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https://en.wikipedia.org/wiki/ProSieben | ProSieben (, sieben is German for "seven"; often stylized as Pro7) is a German free-to-air television network owned by ProSiebenSat.1 Media.
It was launched on 1 January 1989. It is Germany's second-largest privately owned television company. Although ProSieben produces some of its programming itself, it also airs many American imports. On 3 May 2012, the network launched a pay-TV channel called ProSieben Fun. A third channel called ProSieben Maxx started broadcasting on 3 September 2013.
The three different feeds of the channel are: ProSieben (for Germany), ProSieben Austria (for Austria), and ProSieben Schweiz (for Switzerland and Liechtenstein). The main difference is that they have different advertisements and news for each target country.
The channel uses an English slogan: "We love to entertain you."
ProSieben broadcasts from the Astra 1L and 3A satellites and is uplinked by MX1 (now part of SES Video).
History
1988–1993
On 13 October 1988, ProSieben Television GmbH was founded as a successor to Eureka TV. The founding partners were Gerhard Ackermans (51%) and Thomas Kirch (49%). Shortly after, Kirch took complete control of the channel.
On 1 January 1989, ProSieben began broadcasting nine hours of programming a day from Munich. The CEO was Georg Kofler from South Tyrol. ProSieben had 70 employees at that time and claimed to reach 2.44 million viewers.
The station began broadcasting on the DFS Kopernikus satellite in July 1989. Broadcasting hours were gradually increased to 17 hours a day. ProSieben was also awarded the first terrestrial frequency in Munich for a private broadcaster. Starting on 8 December 1989, the station was broadcast via Astra 1A satellite.
On 1 March 1990, the television station moved from Munich-Schwabing to Unterföhring near Munich. At that time, ProSieben had 120 employees. ProSieben has broadcast its programs around the clock since 1 October 1990.
In 1991, ProSieben created a subsidiary called Teledirekt GmbH to promote the spread of satellite technology in Germany. In 1992, although ProSieben was still losing money, it co-founded a special-interest channel, Der Kabelkanal, with German Bundespost TELEKOM. ProSieben held a 45% share. Since initially the channel could only be received via cable connection, the channel helped attract new customers to for Telekom's cable television network. In 1995, ProSieben bought the channel outright and renamed it Kabel 1, and began broadcasting it on the SES Astra satellite.
In July 1992 MGM Media Gruppe München (ProSiebenSat.1 Media today) was established. It was responsible for selling advertising on ProSieben channels. On 24 September 1993, SZM Studios (broadcasting center in Munich, since June 2004: ProSiebenSat.1 Produktion GmbH) was inaugurated. At the end of 1993, ProSieben made a profit for the first time.
1994–1999
In 1994, ProSieben started a teletext service. On 24 October 1994, it started using a new station identity and logo. Turnover in 1994 was DM |
https://en.wikipedia.org/wiki/Post-polio%20syndrome | Post-polio syndrome (PPS, poliomyelitis sequelae) is a group of latent symptoms of poliomyelitis (polio), occurring at about a 25–40% rate (latest data greater than 80%). These symptoms are caused by the damaging effects of the viral infection on the nervous system. Symptoms typically occur 15 to 30 years after an initial acute paralytic attack. Symptoms include decreasing muscular function or acute weakness with pain and fatigue. The same symptoms may also occur years after a nonparalytic polio (NPP) infection.
The precise mechanism that causes PPS is unknown. It shares many features with chronic fatigue syndrome, but unlike that disorder it tends to be progressive and can cause loss of muscle strength. Treatment is primarily limited to adequate rest, conservation of available energy, and supportive measures, such as leg braces and energy-saving devices such as powered wheelchairs, analgesia (pain relief), and sleep aids.
Signs and symptoms
After a period of prolonged stability, individuals who had been infected and recovered from polio begin to experience new signs and symptoms, characterised by muscular atrophy (decreased muscle mass), weakness, pain, and fatigue in limbs that were originally affected or in limbs that did not seem to have been affected at the time of the initial polio illness. PPS is a very slowly progressing condition marked by periods of stability followed by new declines in the ability to carry out usual daily activities. Most patients become aware of their decreased capacity to carry out daily routines due to significant changes in mobility and decreasing upper limb function and lung capability. Fatigue is often the most disabling symptom; even slight exertion often produces disabling fatigue and can also intensify other symptoms. Problems breathing or swallowing, sleep-related breathing disorders, such as sleep apnea, and decreased tolerance for cold temperatures are other notable symptoms.
Increased activity during healthy years between the original infection and onset of PPS can amplify the symptoms. Thus, contracting polio at a young age can result in particularly disabling PPS symptoms.
A possible early occurring and long-lasting sign is a slight jitter exhibited in handwriting.
Mechanism
Numerous theories have been proposed to explain post-polio syndrome. Despite this, no absolutely defined causes of PPS are known. The most widely accepted theory of the mechanism behind the disorder is "neural fatigue". A motor unit is a nerve cell (or neuron) and the muscle fibers it activates. Poliovirus attacks specific neurons in the brainstem and the anterior horn cells of the spinal cord, generally resulting in the death of a substantial fraction of the motor neurons controlling skeletal muscles. In an effort to compensate for the loss of these neurons, surviving motor neurons sprout new nerve terminals to the orphaned muscle fibers. The result is some recovery of movement and the development of enlarged motor units.
The |
https://en.wikipedia.org/wiki/ODI | ODI may refer to:
Object Design, Incorporated, a defunct database software company
One Day International, cricket match
Open Data Institute, a UK not-for-profit company promoting open data
Open Data-Link Interface, an implementation of the OSI model data link layer
Oracle Data Integrator, software used in data transformation
Oral direct inhibitor, a type of anticoagulant
Oswestry Disability Index, a questionnaire for rating the severity of back pain
Outcome-Driven Innovation
Outward direct investment; see Internationalization of the renminbi
Overseas Development Institute, a UK think tank on international development
Odi may refer to:
Odi massacre, a military attack on the town of Odi, Nigeria
Odi Stadium, a stadium in South Africa
See also
Odis (disambiguation) |
https://en.wikipedia.org/wiki/Ambystomatidae | Ambystomatidae is a family of salamanders belonging to the order Caudata in the class Amphibia. It contains two genera, Ambystoma (the mole salamanders) and Dicamptodon (the Pacific giant salamanders). Ambystoma contains 32 species and are distributed widely across North America, while Dicamptodon contains four species restricted to the Pacific Northwest. These salamanders are mostly terrestrial and eat invertebrates, although some species are known to eat smaller salamanders. They can be found throughout the US and some areas of Canada in damp forests or plains. This family contains some of the largest terrestrial salamanders in the world, the tiger salamander and the coastal giant salamander. Some species are toxic and can secrete poison from their bodies as protection against predators or infraspecific competition. Neoteny has been observed in several species in Ambystomatidae, and some of them like the axolotl live all of their lives under water in their larval stage.
Characteristics and Behavior
Ambystomatids have chunky bodies with broad, flat heads and short legs. Tails are long and flattened. Colors range from black, brown, or a dull grey and can have brightly colored speckles or spots. Their skin is smooth and shiny. Most adults lack gills/gill slits and moveable eyes. There are no nasolabial grooves on the snout. Lungs are well-developed and functional. They have 10 costal grooves. Adult males have 6 sets of cloacal glands. Adult females have spermathecae in cloaca. Ambystomatids are nocturnal. Although they are more active at night, they may be found on cool days under moist leaf litter, logs, or rocks near water bodies.
Adults tend to live in burrows and only return to waterbodies or streams to breed in early Spring. Fertilization is internal. Courtship occurs in water; males "dance," nudging the females then deposit numerous spermatophores. Most species have a larval period that extends for 3–4 months. Ambystomatids can be found in temperate forests and wetlands.
Taxonomy
The genus Rhyacotriton was formerly included in this family, but is now usually placed into its own family Rhyacotritonidae. In 2006, a large study of amphibian systematics (Frost et al., Bulletin of the American Museum of Natural History, 297 (2006) placed Dicamptodon back within Ambystomatidae, based on cladistic analysis. This has been accepted by the Center for Indian Herpetology.
References
http://amphibiaweb.org/lists/Ambystomatidae.shtml
http://tolweb.org/Ambystomatidae/15448
External links
Tree of Life: Ambystomatidae
Salamanders
Amphibian families |
https://en.wikipedia.org/wiki/NumPy | NumPy (pronounced ) is a library for the Python programming language, adding support for large, multi-dimensional arrays and matrices, along with a large collection of high-level mathematical functions to operate on these arrays. The predecessor of NumPy, Numeric, was originally created by Jim Hugunin with contributions from several other developers. In 2005, Travis Oliphant created NumPy by incorporating features of the competing Numarray into Numeric, with extensive modifications. NumPy is open-source software and has many contributors. NumPy is a NumFOCUS fiscally sponsored project.
History
matrix-sig
The Python programming language was not originally designed for numerical computing, but attracted the attention of the scientific and engineering community early on. In 1995 the special interest group (SIG) matrix-sig was founded with the aim of defining an array computing package; among its members was Python designer and maintainer Guido van Rossum, who extended Python's syntax (in particular the indexing syntax) to make array computing easier.
Numeric
An implementation of a matrix package was completed by Jim Fulton, then generalized by Jim Hugunin and called Numeric (also variously known as the "Numerical Python extensions" or "NumPy"), with influences from the APL family of languages, Basis, MATLAB, FORTRAN, S and S+, and others.
Hugunin, a graduate student at the Massachusetts Institute of Technology (MIT), joined the Corporation for National Research Initiatives (CNRI) in 1997 to work on JPython, leaving Paul Dubois of Lawrence Livermore National Laboratory (LLNL) to take over as maintainer. Other early contributors include David Ascher, Konrad Hinsen and Travis Oliphant.
Numarray
A new package called Numarray was written as a more flexible replacement for Numeric. Like Numeric, it too is now deprecated. Numarray had faster operations for large arrays, but was slower than Numeric on small ones, so for a time both packages were used in parallel for different use cases. The last version of Numeric (v24.2) was released on 11 November 2005, while the last version of numarray (v1.5.2) was released on 24 August 2006.
There was a desire to get Numeric into the Python standard library, but Guido van Rossum decided that the code was not maintainable in its state then.
NumPy
In early 2005, NumPy developer Travis Oliphant wanted to unify the community around a single array package and ported Numarray's features to Numeric, releasing the result as NumPy 1.0 in 2006. This new project was part of SciPy. To avoid installing the large SciPy package just to get an array object, this new package was separated and called NumPy. Support for Python 3 was added in 2011 with NumPy version 1.5.0.
In 2011, PyPy started development on an implementation of the NumPy API for PyPy. It is not yet fully compatible with NumPy.
Features
NumPy targets the CPython reference implementation of Python, which is a non-optimizing bytecode interpreter. Mathematical alg |
https://en.wikipedia.org/wiki/OpenMP | OpenMP (Open Multi-Processing) is an application programming interface (API) that supports multi-platform shared-memory multiprocessing programming in C, C++, and Fortran, on many platforms, instruction-set architectures and operating systems, including Solaris, AIX, FreeBSD, HP-UX, Linux, macOS, and Windows. It consists of a set of compiler directives, library routines, and environment variables that influence run-time behavior.
OpenMP is managed by the nonprofit technology consortium OpenMP Architecture Review Board (or OpenMP ARB), jointly defined by a broad swath of leading computer hardware and software vendors, including Arm, AMD, IBM, Intel, Cray, HP, Fujitsu, Nvidia, NEC, Red Hat, Texas Instruments, and Oracle Corporation.
OpenMP uses a portable, scalable model that gives programmers a simple and flexible interface for developing parallel applications for platforms ranging from the standard desktop computer to the supercomputer.
An application built with the hybrid model of parallel programming can run on a computer cluster using both OpenMP and Message Passing Interface (MPI), such that OpenMP is used for parallelism within a (multi-core) node while MPI is used for parallelism between nodes. There have also been efforts to run OpenMP on software distributed shared memory systems, to translate OpenMP into MPI
and to extend OpenMP for non-shared memory systems.
Design
OpenMP is an implementation of multithreading, a method of parallelizing whereby a primary thread (a series of instructions executed consecutively) forks a specified number of sub-threads and the system divides a task among them. The threads then run concurrently, with the runtime environment allocating threads to different processors.
The section of code that is meant to run in parallel is marked accordingly, with a compiler directive that will cause the threads to form before the section is executed. Each thread has an ID attached to it which can be obtained using a function (called omp_get_thread_num()). The thread ID is an integer, and the primary thread has an ID of 0. After the execution of the parallelized code, the threads join back into the primary thread, which continues onward to the end of the program.
By default, each thread executes the parallelized section of code independently. Work-sharing constructs can be used to divide a task among the threads so that each thread executes its allocated part of the code. Both task parallelism and data parallelism can be achieved using OpenMP in this way.
The runtime environment allocates threads to processors depending on usage, machine load and other factors. The runtime environment can assign the number of threads based on environment variables, or the code can do so using functions. The OpenMP functions are included in a header file labelled in C/C++.
History
The OpenMP Architecture Review Board (ARB) published its first API specifications, OpenMP for Fortran 1.0, in October 1997. In October the followin |
https://en.wikipedia.org/wiki/Clifford%20Berry | Clifford Edward Berry (April 19, 1918 – October 30, 1963) helped John Vincent Atanasoff create the first digital electronic computer in 1939, the Atanasoff–Berry computer (ABC).
Biography
Clifford Berry was born April 19, 1918, in Gladbrook, Iowa, to Fred and Grace Berry. His father owned an appliance repair shop, where he was able to learn about radios. He graduated from Marengo High School in Marengo, Iowa, in 1934 as the class valedictorian at age 16. He went on to study at Iowa State College (now known as Iowa State University), eventually earning a bachelor's degree in electrical engineering in 1939 and followed by his master's degree in physics in 1941.
In 1942, he married an ISU classmate and Atanasoff's secretary, Martha Jean Reed.
By 1948, he earned his PhD in physics from Iowa State University.
He died in 1963, attributed to "possible suicide".
References
External links
1942 and 1962 photos of Berry, Ames Laboratory Archive, Iowa State
Atanasoff-Berry Computer Archive, Computer Science Dept., Iowa State
June 7, 1972 interview with Atanasoff on Berry, Smithsonian National Museum of American History
A. R. Mackintosh, “Dr. Atanasoff’s Computer”, Scientific American, August 1988 (Archived 2009-10-31)
"ABC - Atanasoff-Berry Computer", I Programmer
IEEE Computer Pioneers Biography Entry
American computer scientists
20th-century American physicists
Iowa State University alumni
1918 births
1963 deaths |
https://en.wikipedia.org/wiki/Block%20%28programming%29 | In computer programming, a block or code block or block of code is a lexical structure of source code which is grouped together. Blocks consist of one or more declarations and statements. A programming language that permits the creation of blocks, including blocks nested within other blocks, is called a block-structured programming language. Blocks are fundamental to structured programming, where control structures are formed from blocks.
Blocks have two functions: to group statements so that they can be treated as one statement, and to define scopes for names to distinguish them from the same name used elsewhere. In a block-structured programming language, the objects named in outer blocks are visible inside inner blocks, unless they are masked by an object declared with the same name.
History
Ideas of block structure were developed in the 1950s during the development of the first autocodes, and were formalized in the Algol 58 and Algol 60 reports. Algol 58 introduced the notion of the "compound statement", which was related solely to control flow. The subsequent Revised Report which described the syntax and semantics of Algol 60 introduced the notion of a block and block scope, with a block consisting of " A sequence of declarations followed by a sequence of statements and enclosed between begin and end..." in which "[e]very declaration appears in a block in this way and is valid only for that block."
Syntax
Blocks use different syntax in different languages. Two broad families are:
the ALGOL family in which blocks are delimited by the keywords "begin" and "end" or equivalent. In C, blocks are delimited by curly braces - "{" and "}". ALGOL 68 uses parentheses.
Parentheses - "(" and ")", are used in the MS-DOS batch language
indentation, as in Python
s-expressions with a syntactic keyword such as prog or let (as in the Lisp family)
In 1968 (with ALGOL 68), then in Edsger W. Dijkstra's 1974 Guarded Command Language the conditional and iterative code block are alternatively terminated with the block reserved word reversed: e.g. if ~ then ~ elif ~ else ~ fi, case ~ in ~ out ~ esac and for ~ while ~ do ~ od
Limitations
Some languages which support blocks with declarations do not fully support all declarations; for instance many C-derived languages do not permit a function definition within a block (nested functions). And unlike its ancestor Algol, Pascal does not support the use of blocks with their own declarations inside the begin and end of an existing block, only compound statements enabling sequences of statements to be grouped together in if, while, repeat and other control statements.
Basic semantics
The semantic meaning of a block is twofold. Firstly, it provides the programmer with a way for creating arbitrarily large and complex structures that can be treated as units. Secondly, it enables the programmer to limit the scope of variables and sometimes other objects that have been declared.
In early languages such as Fortran IV an |
https://en.wikipedia.org/wiki/Hal%20Abelson | Harold Abelson (born April 26, 1947) is the Class of 1922 Professor of Computer Science and Engineering in the Department of Electrical Engineering and Computer Science at the Massachusetts Institute of Technology (MIT), a founding director of both Creative Commons and the Free Software Foundation, creator of the MIT App Inventor platform, and co-author of the widely-used textbook Structure and Interpretation of Computer Programs, sometimes also referred to as "the wizard book."
He directed the first implementation of the language Logo for the Apple II, which made the language widely available on personal computers starting in 1981; and published a widely selling book on Logo in 1982. Together with Gerald Jay Sussman, Abelson developed MIT's introductory computer science subject, The Structure and Interpretation of Computer Programs (called by the course number, 6.001), a subject organized around the idea that a computer language is primarily a formal medium for expressing ideas about methodology, rather than just a way to get a computer to perform operations. Abelson and Sussman also cooperate in codirecting the MIT Project on Mathematics and Computation. The MIT OpenCourseWare (OCW) project was spearheaded by Abelson and other MIT faculty.
Abelson led an internal investigation of MIT's choices and role in the prosecution of Aaron Swartz by the Federal Bureau of Investigation (FBI), which concluded that MIT did nothing wrong legally, but recommended that MIT consider changing some of its internal policies.
Education
Abelson graduated with a Bachelor of Arts degree in mathematics from Princeton University in 1969 after completing a senior thesis on Actions with fixed-point set: a homology sphere, supervised by William Browder.
He received his PhD in mathematics from the Massachusetts Institute of Technology in 1973 after completing his research on Topologically distinct conjugate varieties with finite fundamental group supervised by Dennis Sullivan.
Career and research
Abelson is also a founding director of Creative Commons and Public Knowledge, and a director of the Center for Democracy and Technology.
Computer science education
Abelson has a longstanding interest in using computation as a conceptual framework in teaching. He directed the first implementation of Logo for the Apple II, which made the language widely available on personal computers starting in 1981; and published a widely selling book on Logo in 1982. His book Turtle Geometry, written with Andrea diSessa in 1981, presented a computational approach to geometry which has been cited as "the first step in a revolutionary change in the entire teaching/learning process." In March 2015, a copy of Abelson's 1969 implementation of Turtle graphics was sold at The Algorithm Auction, the world’s first auction of computer algorithms.
Together with Gerald Jay Sussman, Abelson developed MIT's introductory computer science subject, Structure and Interpretation of Computer Programs, a subje |
https://en.wikipedia.org/wiki/Eircell | Eircell was an Irish mobile cellular network provider which was established in 1984, with operations commencing in 1986. Its access code was 088 for the original analogue TACS system and 087 for the later GSM system. Following the abolition of the Department of Posts and Telegraphs, Eircell fell under the remit of Telecom Éireann (Later Eircom), which today is known as Eir. The Eircell brand became defunct in 2002 following its acquisition by Vodafone. From 2001, Eircell underwent a major branding exercise after its acquisition by the Vodafone group in December 2000. The main branding was to associate a shade of deep purple with the company. When Vodafone rebranded with its trademark shade of red, the company commented that "red is the new purple". The company was known as Eircell-Vodafone for some time as the process took nine months in total.
History
Early stages of Eircell
In the late 1980s, early adopters of the service numbered in their hundreds rather than thousands and paid handsomely for the phones that were available at the time through a network of independent retailers. The price for mobile phones ranged from IR£1500 to IR£2000 and 'subscribers' were typically politicians or wealthy businessmen. The market-leading phone manufacturers in the early years of the Irish market were Nokia and Motorola.
Popularity of the company rises
In response to negative publicity about security compromises on the TACS system during the early 1990s, Eircell introduced Ireland's first encrypted cellular phone called a Kokusai and it retailed in the region of IR£1400. Sales were poor partly because Eircell was not in the business of selling phones and because switching from encrypted to unencrypted was 'messy'. As phone prices dropped and the network rolled out to more of Ireland, sales took off reaching a milestone 100,000 subscribers by 1995 and in 1997, Eircell launched Ireland's first prepaid mobile phone service which was called 'Ready To Go'. A year later, it launched its GSM 900 networks (access code 087) which quickly took hold as users rapidly switched over to the new digital technology.
See also
Communications in Ireland
Vodafone Ireland
References
External links
Official site (Vodafone, Ireland)
The Telegraph - December 2000 - Vodafone's acquisition of Eircell
Business2000.ie - Eircell Case Study
Mobile telecommunications networks |
https://en.wikipedia.org/wiki/List%20of%20Syfy%20TV%20channels | Syfy (in some countries named Sci Fi) is a family of pay television channels that broadcast programming owned or licensed by entertainment NBCUniversal around the world using the Syfy brand which is focused on science fiction, fantasy, horror, supernatural and paranormal programming. The first such channel was launched in the United States on September 24, 1992. It was originally named "Sci-Fi Channel". In 1995 it kicked off in the United Kingdom, followed by the Netherlands and Belgium in 1996.
The name Syfy was officially adopted on July 7, 2009, and most were renamed Syfy Universal by 2010. Exceptions to this renaming scheme included Syfy Channels in USA, Germany, France, Latin America, Spain, Portugal and future Syfy Channels in Canada, Cyprus, Israel, Nordic countries, South Africa, Türkiye and now defunct and replaced SF Australia (formerly Sci Fi Channel Australia) and Syfy UK, where the channel is simply called Syfy. Sci Fi Channels in Poland, Serbia, Slovenia and future Sci Fi Channels in Greece, Malta and now defunct Sci Fi Channel in Romania, became Sci Fi Universal due to syfy having a profane meaning in Polish. In 2017 the channel got rebranded but the Universal suffix was already dropped.
The list of Syfy or Sci Fi channels around the world
See also
CTV Sci-Fi Channel, a Canadian television channel that shows most of Sci-Fi Channel/Syfy's programming
References
NBCUniversal networks
Science fiction television channels
Syfy
Universal Networks International |
https://en.wikipedia.org/wiki/Streaker | Streaker may refer to:
Someone who engages in streaking, purposely appearing and running nude in public
Streaker (dinghy), a sailing dinghy
Streaker (video game), a 1987 computer game published by Bulldog
Combat Vehicle Reconnaissance (tracked), a high-mobility carrier vehicle named Streaker, from the United Kingdom
Streaker (SpaceDev), a small launch vehicle
MQM-107 Streaker, a target-towing drone used by the U.S. Army and Air Force
The Streaker, a starship crewed by dolphins, from David Brin's Uplift Universe novels
See also
Streak (disambiguation) |
https://en.wikipedia.org/wiki/Electronic%20Recording%20Machine%2C%20Accounting | ERMA (Electronic Recording Machine, Accounting) was a computer technology that automated bank bookkeeping and check processing. Developed at the nonprofit research institution SRI International under contract from Bank of America, the project began in 1950 and was publicly revealed in September 1955.
Payments experts contend that ERMA "established the foundation for computerized banking, magnetic ink character recognition (MICR), and credit-card processing". General Electric (GE) won the production contract, deciding to transistorize the design in the process. Calling the machine the GE-100, a total of 32 ERMA machines were built. GE would use this experience to develop several mainframe computer lines before selling the division to Honeywell in 1970.
History
Background
In 1950, Bank of America (BoA) was the largest bank in California, and led the world in the use of checks. This presented a serious problem due to the workload processing time. An experienced bookkeeper could post 245 accounts in an hour, about 2,000 in an eight-hour workday and approximately 10,000 per week. Bank of America's checking accounts were growing at a rate of 23,000 per month and banks were being forced to close their doors by 2 p.m. to finish daily postings.
S. Clark Beise was a senior vice president at BoA who was introduced to Thomas H. Morrin, SRI's Director of Engineering. They formed an alliance under which SRI would essentially act as BoA's research and development arm. In July 1950 they contracted SRI for an initial feasibility study for automating their bookkeeping and check handling. ERMA was under the technical leadership of computer scientist Jerre Noe.
First study
SRI immediately found a problem. Because accounts were kept alphabetically, adding a new account required a reshuffling of the account listings. SRI instead suggested using account numbers, simply adding new ones to the end of the list. In addition these numbers would be pre-printed on checks, thereby dramatically reducing the time to match the checks with account information (known as "proofing"). Numbered accounts are now a feature of almost all banks.
With that problem out of the way, SRI returned a report in September 1950 that stated a computer-based system was certainly feasible, which they called the Electronic Recording Machine (ERM).
Second study
Bank of America then offered a second six-month contract in November to fully study the changes needed to banking procedures, and design the logical layout of production ERM machines. While this was underway, Bank of America went to a number of industrial companies to set up production of the machines, but none were interested. So SRI was given another contract in January 1952 to build a prototype machine.
One of the biggest problems found in the second phase was how to input the check information, especially the account numbers, with any sort of speed. Beise demanded a system that would not require the information to be changed from |
https://en.wikipedia.org/wiki/IGS | IGS may stand for:
Computers/Video Games
Information Global Service, Japanese video game company
Initial Graphics Exchange Specification, file extension .igs
InteGraphics Systems a former chip manufacturer
Interactive geometry software
Internet Go server, for the game of Go
IGS Go server, Japanese Go server
Technology
Image guided surgery
Information Gathering Satellites, Japan
Instrument guidance system
Science
Institute of General Semantics
Intergenic spacer
International Glaciological Society
International Graphonomics Society
International GNSS Service
Schools
Ilkley Grammar School
International Grammar School, Sydney
Ipswich Grammar School
Islington Green School
Other
Imerslund-Gräsbeck syndrome
International Graduates Scheme, a UK immigration scheme
Irish Georgian Society |
https://en.wikipedia.org/wiki/CQ | CQ may refer to:
Arts and entertainment
CQ (film), a 2001 film
La CQ, a Cartoon Network sitcom
Cinémathèque québécoise, a Montreal film museum
People
CQ (playwright) or C. Quintana, a Cuban-American playwright, poet, and writer
Charles Q. Brown Jr., current Chairman of the Joint Chiefs of Staff.
Places
Central Queensland (geographical division of Queensland)
Chongqing, China (Guobiao abbreviation CQ)
Northern Mariana Islands (FIPS Pub 10-4 or obsolete NATO digram CQ)
Sark, Channel Islands (ISO 3166-1 alpha-2 exceptionally reserved code CQ for Sark)
Publications
CQ Amateur Radio
CQ ham radio
CQ Press, a US publisher in government and politics
The China Quarterly, a journal published by Cambridge University Press
Congressional Quarterly, a US publishing company
Science and technology
Conjunctive query, in relational databases and database theory
CQ (call), in radio communications, a general call, to anyone who receives it
Norinco CQ, a variant of the AR-15 rifle
Cissus quadrangularis, medicinal plant from the grape family
Adobe Experience Manager, formerly CQ, a web content management system
Other uses
Cadit quaestio, Latin for "the question falls", in copy-editing means "has been checked"
Carrier qualification, qualifications for modern US Navy carrier air operations
Charge of Quarters, the military task of guarding the front entrance to a barracks
Communication quotient, in business and organizational psychology
Constellation Airlines (IATA airline designator CQ)
Cultural Quotient, in business, education, government and academic research
Knight of the National Order of Quebec (post-nominal letters CQ) |
https://en.wikipedia.org/wiki/DF | DF or df may refer to:
Gaming
DeFRaG, a modification for the computer game Quake III Arena
DragonFable, a 2006 video game by Artix Entertainment
Dwarf Fortress, a 2006 sandbox-style computer game
Places
Distrito Federal (Brazil), or the Federal District
Distrito Federal (Mexico), or the Federal District, now known as Mexico City
Politics
Danish People's Party (Dansk Folkeparti)
Democratic Front (Bosnia and Herzegovina) (Demokratska fronta)
Democratic Front (Montenegro) (Demokratski front)
Science and technology
df (Unix), a Unix command to report disk space usage by a filesystem
Dairy free, identifying products that contain no milk
Decapacitation factor, in biochemistry
Degrees of freedom, various measures in statistics, mathematics and physics
Density function, a mathematical function with a wide range of applications
Dielectric loss
Direction finding, a technique used to locate radio transmitters
Direction flag, a flag stored in the FLAGS register on all x86-compatible CPUs
Dissipation factor, a measure of loss-rate of energy of an oscillation mode in a dissipative system
Dongfeng (missile), a Chinese intercontinental ballistic missile
Dongfeng series of diesel locomotives
China Railways DF
China Railways DF4
China Railways DF8
Methylphosphonyl difluoride, a chemical weapons precursor
Daylight factor (DF), the ratio of the light level inside a structure to the light level outside the structure.
Other uses
Defender (association football)
Delta Force, a component of the U.S. Army Joint Special Operations Command
Design Factory, a department of Aalto University
Duty Free, goods which are free from tax or duty
New Zealand DF class locomotive (1979)
Quantum Air (formerly AeBal), Spanish airline (IATA code DF)
Disfellowshipping (see Jehovah's Witnesses and congregational discipline)
See also
Dongfeng (disambiguation) |
https://en.wikipedia.org/wiki/Peter%20G.%20Neumann | Peter Gabriel Neumann (born 1932) is a computer-science researcher who worked on the Multics operating system in the 1960s. He edits the RISKS Digest columns for ACM Software Engineering Notes and Communications of the ACM. He founded ACM SIGSOFT and is a Fellow of the ACM, IEEE, and AAAS.
Early life and education
Neumann holds three degrees from Harvard University: an A.B. (1954) in Mathematics, and an S.M. (1955) and Ph.D. (1961) in Applied Mathematics and Science. He held a Fulbright scholarship in Germany from 1958–1960.
While a student at Harvard, he had a two-hour breakfast with Albert Einstein, on 8 November 1952, discussing simplicity in design.
Career
Neumann worked at Bell Labs from 1960 to 1970. He has worked at SRI International in Menlo Park, California since 1971.
Before the RISKS mailing list, Neumann was known for the Provably Secure Operating System (PSOS).
Neumann worked with Dorothy E. Denning in the 1980s to develop a computer intrusion detection system known as IDES that was a model for later computer security software.
Memberships and awards
Neumann has long served as moderator of RISKS Digest and is a member of the ACCURATE project.
Neumann is the founding editor of ACM Software Engineering Notes (SEN), and is a Fellow of the ACM.
In 2018, Neumann received the EPIC Lifetime Achievement Award from Electronic Privacy Information Center.
Selected publications
Neumann, Peter G., Computer-Related Risks, Addison-Wesley/ACM Press, , 1995.
References
External links
Home page
Short biography
RISKS Forum archive
Peter G. Neumann oral history, Charles Babbage Institute, University of Minnesota
1932 births
Living people
Harvard John A. Paulson School of Engineering and Applied Sciences alumni
American computer scientists
Fellows of the Association for Computing Machinery
Fellow Members of the IEEE
Fellows of the American Association for the Advancement of Science
Multics people
Computer security specialists
Scientists at Bell Labs
SRI International people
Computer science writers
Fulbright alumni |
https://en.wikipedia.org/wiki/Mitel | Mitel Networks Corporation is a Canadian telecommunications company. The company previously produced TDM PBX systems and applications, but after a change in ownership in 2001, now focuses almost entirely on Voice-over-IP (VoIP), unified communications, collaboration and contact center products. Mitel is headquartered in Ottawa, Ontario, Canada, with offices, partners and resellers worldwide.
In April 2018, the company announced it had been bought by an investor group led by Searchlight Capital Partners.
History
Founding
Michael Cowpland and Terry Matthews founded Mitel in 1973 (officially on June 8, 1973). Conventionally, its name is regarded as a combination of the founders’ first names and their first product, Mike and Terry Lawnmowers. Michael Cowpland stated that the name stands for Mike and Terry Lawnmowers, whereas Terry Matthews confirmed the lawnmower acronym during an interview on BBC Radio 4's The Bottom Line in May 2011.
Cowpland and Matthews formed the corporation with the blessing of their employer, Bell Northern Research, in order to protect their intellectual property rights of the converter design from their employer, who otherwise would have legal ownership rights.
Their first shipment of three lawnmowers was lost in shipping, so they quickly adjusted to produce a telephony tone receiver product (a tone-to-pulse converter for central office use based on Cowpland's Ph.D. thesis). Michael Cowpland has also stated that the lawnmowers were not suited to Canadian lawns.
Following the success of the tone receiver, the founders extended their interest in the telecommunications industry. Early on, the pair realized the significance of the then-new microprocessor and software technology to the design of telecom switches. In 1975, they introduced the SX200 PBX. The company grew at a rate of over 100% per year for several years. They reached the $100 million annual revenue mark by 1981.
In 1976, the company expanded into the semiconductor field with the acquisition of Siltex, a bankrupt ISO-CMOS foundry in Bromont, Quebec. This evolved into a semiconductor division that specialized in mixed signal and thick film hybrid devices.
The next major product was a large digital PBX called the SX2000. This was an early attempt to integrate the voice and data functions of office systems. It was conceived as moving beyond the PBX to become an Office Controller, which would handle both voice and data applications within an organization.
In 1985, due to a financial crisis in the company, the board of directors created enough new shares to sell a controlling interest (51%) to British Telecom. British Telecom left the equipment business a few years later and sold its controlling interest in Mitel to an investment company called Schroder Ventures. Schroeder Ventures installed new management, which revitalized the company.
In the meantime, Mitel continued to diversify its product line, introducing the successful SUPERSET line of phone terminal |
https://en.wikipedia.org/wiki/EWR%20%28disambiguation%29 | EWR is the IATA airport code for Newark Liberty International Airport.
EWR may also refer to:
Entwicklungsring Süd, a German aircraft manufacturer
Extreme Warfare Revenge, a computer game
Early-warning radar, a radar detection system
Rail
East West Rail, a proposed rail line in England
Elkhart and Western Railroad, a railroad in Indiana, United States
East Worthing railway station, Sussex, England |
https://en.wikipedia.org/wiki/Algorithmic%20learning%20theory | Algorithmic learning theory is a mathematical framework for analyzing
machine learning problems and algorithms. Synonyms include formal learning theory and algorithmic inductive inference. Algorithmic learning theory is different from statistical learning theory in that it does not make use of statistical assumptions and analysis. Both algorithmic and statistical learning theory are concerned with machine learning and can thus be viewed as branches of computational learning theory.
Distinguishing characteristics
Unlike statistical learning theory and most statistical theory in general, algorithmic learning theory does not assume that data are random samples, that is, that data points are independent of each other. This makes the theory suitable for domains where observations are (relatively) noise-free but not random, such as language learning and automated scientific discovery.
The fundamental concept of algorithmic learning theory is learning in the limit: as the number of data points increases, a learning algorithm should converge to a correct hypothesis on every possible data sequence consistent with the problem space. This is a non-probabilistic version of statistical consistency, which also requires convergence to a correct model in the limit, but allows a learner to fail on data sequences with probability measure 0 .
Algorithmic learning theory investigates the learning power of Turing machines. Other frameworks consider a much more restricted class of learning algorithms than Turing machines, for example, learners that compute hypotheses more quickly, for instance in polynomial time. An example of such a framework is probably approximately correct learning .
Learning in the limit
The concept was introduced in E. Mark Gold's seminal paper "Language identification in the limit". The objective of language identification is for a machine running one program to be capable of developing another program by which any given sentence can be tested to determine whether it is "grammatical" or "ungrammatical". The language being learned need not be English or any other natural language - in fact the definition of "grammatical" can be absolutely anything known to the tester.
In Gold's learning model, the tester gives the learner an example sentence at each step, and the learner responds with a hypothesis, which is a suggested program to determine grammatical correctness. It is required of the tester that every possible sentence (grammatical or not) appears in the list eventually, but no particular order is required. It is required of the learner that at each step the hypothesis must be correct for all the sentences so far.
A particular learner is said to be able to "learn a language in the limit" if there is a certain number of steps beyond which its hypothesis no longer changes. At this point it has indeed learned the language, because every possible sentence appears somewhere in the sequence of inputs (past or future), and the hypothesis i |
https://en.wikipedia.org/wiki/Chaos%20model | In computing, the chaos model is a structure of software development. Its creator, who used the pseudonym L.B.S. Raccoon, noted that project management models such as the spiral model and waterfall model, while good at managing schedules and staff, didn't provide methods to fix bugs or solve other technical problems. At the same time, programming methodologies, while effective at fixing bugs and solving technical problems, do not help in managing deadlines or responding to customer requests. The structure attempts to bridge this gap. Chaos theory was used as a tool to help understand these issues.
Software development life cycle
The chaos model notes that the phases of the life cycle apply to all levels of projects, from the whole project to individual lines of code.
The whole project must be defined, implemented, and integrated.
Systems must be defined, implemented, and integrated.
Modules must be defined, implemented, and integrated.
Functions must be defined, implemented, and integrated.
Lines of code are defined, implemented and integrated.
One important change in perspective is whether projects can be thought of as whole units, or must be thought of in pieces. Nobody writes tens of thousands of lines of code in one sitting. They write small pieces, one line at a time, verifying that the small pieces work. Then they build up from there. The behavior of a complex system emerges from the combined behavior of the smaller building blocks.
Chaos strategy
The chaos strategy is a strategy of software development based on the chaos model. The main rule is always resolve the most important issue first.
An issue is an incomplete programming task.
The most important issue is a combination of big, urgent, and robust.
Big issues provide value to users as working functionality.
Urgent issues are timely in that they would otherwise hold up other work.
Robust issues are trusted and tested when resolved. Developers can then safely focus their attention elsewhere.
To resolve means to bring it to a point of stability.
The chaos strategy resembles the way that programmers work toward the end of a project, when they have a list of bugs to fix and features to create. Usually someone prioritizes the remaining tasks, and the programmers fix them one at a time. The chaos strategy states that this is the only valid
way to do the work.
The chaos strategy was inspired by Go strategy.
Connections with chaos theory
There are several tie-ins with chaos theory.
The chaos model may help explain why software tends to be so unpredictable.
It explains why high-level concepts like architecture cannot be treated independently of low-level lines of code.
It provides a hook for explaining what to do next, in terms of the chaos strategy.
See also
V-model
References
Further reading
Roger Pressman (1997) Software Engineering: A Practitioner's Approach 4th edition, pages 29–30, McGraw Hill.
Raccoon (1995) The Chaos Model and the Chaos Life Cycle, in ACM So |
https://en.wikipedia.org/wiki/Index%20register | An index register in a computer's CPU is a processor register (or an assigned memory location) used for pointing to operand addresses during the run of a program. It is useful for stepping through strings and arrays. It can also be used for holding loop iterations and counters. In some architectures it is used for read/writing blocks of memory. Depending on the architecture it may be a dedicated index register or a general-purpose register. Some instruction sets allow more than one index register to be used; in that case additional instruction fields may specify which index registers to use.
Generally, the contents of an index register is added to (in some cases subtracted from) an immediate address (that can be part of the instruction itself or held in another register) to form the "effective" address of the actual data (operand). Special instructions are typically provided to test the index register and, if the test fails, increments the index register by an immediate constant and branches, typically to the start of the loop. While normally processors that allow an instruction to specify multiple index registers add the contents together, IBM had a line of computers in which the contents were or'd together.
Index registers has proved useful for doing vector/array operations and in commercial data processing for navigating from field to field within records. In both uses index registers substantially reduced the amount of memory used and increased execution speed.
History
In early computers without any form of indirect addressing, array operations had to be performed by modifying the instruction address, which required several additional program steps and used up more computer memory, a scarce resource in computer installations of the early era (as well as in early microcomputers two decades later).
Index registers, commonly known as B-lines in early British computers, as B-registers on some machines and a X-registers on others, were first used in the British Manchester Mark 1 computer, in 1949. In general, index registers became a standard part of computers during the technology's second generation, roughly 1954–1966. Most machines in the IBM 700/7000 mainframe series had them, starting with the IBM 704 in 1954, though they were optional on some smaller machines such as the IBM 650 and IBM 1401.
Early "small machines" with index registers include the AN/USQ-17, around 1960, and the 9 series of real-time computers from Scientific Data Systems, from the early 1960s.
The 1962 UNIVAC 1107 has 15 X-registers, four of which were also A-registers.
The 1964 GE-635 has 8 dedicated X-registers; however, it also allows indexing by the instruction counter or by either half of the A or Q register.
The Digital Equipment Corporation (DEC) PDP-6, introduced in 1964, and the IBM System/360, announced in 1964, do not include dedicated index registers; instead, they have general-purpose registers (called "accumulators" in the PDP-6) that can contain eithe |
https://en.wikipedia.org/wiki/NEC | is a Japanese multinational information technology and electronics corporation, headquartered at the NEC Supertower in Minato, Tokyo, Japan. It provides IT and network solutions, including cloud computing, artificial intelligence (AI), Internet of Things (IoT) platform, and telecommunications equipment and software to business enterprises, communications services providers and to government agencies, and has also been the biggest PC vendor in Japan since the 1980s when it launched the PC-8000 series.
NEC was the world's fourth-largest PC manufacturer by 1990. Its semiconductors business unit was the world's largest semiconductor company by annual revenue from 1985 to 1992, the second largest in 1995, one of the top three in 2000, and one of the top 10 in 2006. NEC spun off its semiconductor business to Renesas Electronics and Elpida Memory. Once Japan's major electronics company, NEC has largely withdrawn from manufacturing since the beginning of the 21st century.
NEC was #463 on the 2017 Fortune 500 list. NEC is a member of the Sumitomo Group.
History
NEC
Kunihiko Iwadare and Takeshiro Maeda established Nippon Electric Limited Partnership on August 31, 1898, by using facilities that they had bought from Miyoshi Electrical Manufacturing Company. Iwadare acted as the representative partner; Maeda handled company sales. Western Electric, which had an interest in the Japanese phone market, was represented by Walter Tenney Carleton. Carleton was also responsible for the renovation of the Miyoshi facilities. It was agreed that the partnership would be reorganized as a joint-stock company when the treaty would allow it. On July 17, 1899, the revised treaty between Japan and the United States went into effect. Nippon Electric Company, Limited was organized the same day as Western Electric Company to become the first Japanese joint-venture with foreign capital. Iwadare was named managing director. Ernest Clement and Carleton were named as directors. Maeda and Mototeru Fujii were assigned to be auditors. Iwadare, Maeda, and Carleton handled the overall management.
The company started with the production, sales, and maintenance of telephones and switches. NEC modernized the production facilities with the construction of the Mita Plant in 1901 at Mita Shikokumachi. It was completed in December 1902.
The Japanese Ministry of Communications adopted a new technology in 1903: the common battery switchboard supplied by NEC. The common battery switchboards powered the subscriber phone, eliminating the need for a permanent magnet generator in each subscriber's phone. The switchboards were initially imported, but were manufactured locally by 1909.
NEC started exporting telephone sets to China in 1904. In 1905, Iwadare visited Western Electric in the U.S. to see their management and production control. On his return to Japan, he discontinued the "oyakata" system of sub-contracting and replaced it with a new system where managers and employees were all direct |
https://en.wikipedia.org/wiki/List%20of%20United%20States%20defense%20contractors | The Top 100 Contractors Report on the Federal Procurement Data System lists the top 100 defense contractors by sales to the United States Armed Forces and Department of Defense. ('DoD 9700' worksheet). The Department of Defense announces contracts valued at $7 million or more each business day at 5 pm. All defense contractors maintain CAGE (Commercial and Government Entity) Codes and are profiled in the System for Award Management (SAM).
List of Top 100 United States defense contractors
Academi
Action Target
ADT Corporation
Advanced Armament Corporation
AECOM
Aerospace Corporation
Aerovironment
AirScan
AM General
American Petroleum Institute
Argon ST
ARINC
Artis
Assett
Astronautics Corporation of America
Atec
Aurora Flight Sciences
Axon Enterprise
BAE Systems
BAE Systems Inc
Ball Corporation
Ball Aerospace & Technologies
Barrett Firearms Manufacturing
Battelle Memorial Institute
Bechtel
Berico Technologies
Boeing Defense, Space & Security
Insitu
Booz Allen Hamilton
Boston Dynamics
Bravo Strategic
CACI
Carlyle Group
Carnegie Mellon University
Ceradyne
Cloudera
Colt Defense
The Columbia Group
Computer Sciences Corporation
Concurrent Technologies Corporation
CSRA (IT services company)
Cubic Corporation
Omega Training Group
Curtiss-Wright
DeciBel Research
Dillon Aero
Dine Development Corporation
Draper Laboratories
DRS Technologies
DynCorp
Edison Welding Institute
Elbit Systems
M7 Aerospace
Ensco
/ Ernst & Young
Evergreen International Aviation
Exxon
Fluor Corporation
Force Protection Inc
Foster-Miller
Foster Wheeler
Franklin Armoury
General Atomics
General Dynamics
Bath Iron Works
General Dynamics Electric Boat
Gulfstream
Vangent
General Electric Military Jet Engines Division
Halliburton Corporation
Health Net
Hewlett-Packard
Honeywell
Humana Inc.
Huntington Ingalls Industries
Hybricon Corporation
IBM
Insight Technology
Intelsat
International Resources Group
iRobot
ITT Exelis
Jacobs Engineering Group
JANUS Research Group
Johns Hopkins University
Kaman Aircraft
KBR
Kearfott Corporation
Knight's Armament Company
Kratos Defense & Security Solutions
L3Harris Technologies
Aerojet
Brashear
/ Lafayette Praetorian Group
Lake Shore Systems
Leidos
EOTech
Lewis Machine & Tool Company
Lockheed Martin
Gyrocam Systems
Sikorsky
LRAD Corporation
ManTech International
Maxar Technologies
McQ
Microsoft
Mission Essential Personnel
Motorola
Natel Electronic Manufacturing Services
Navistar Defense
Nextel
Northrop Grumman
Northrop Grumman Electronic Systems
Northrop Grumman Ship Systems
Northrop Grumman Technical Services
Northrop Grumman Innovation Systems
NOVA
Oceaneering International
Olin Corporation; also see John M. Olin and John M. Olin Foundation
Oshkosh Corporation
Para-Ordnance
Perot Systems
Picatinny Arsenal
Pinnacle Armor
Precision Castparts Corporation
Raytheon Technologies
Collins Aerospace
Rockwell Collins
Goodrich Corporation
Pr |
https://en.wikipedia.org/wiki/MOBIDIC | Sylvania's MOBIDIC, short for "MOBIle DIgital Computer", was a transistorized computer intended to store, sort and route information as one part of the United States Army's Fieldata concept. Fieldata aimed to automate the distribution of battlefield data in any form, ensuring the delivery of reports to the proper recipients regardless of the physical form they were sent or received. MOBIDIC was mounted in the trailer of a semi-trailer truck, while a second supplied power, allowing it to be moved about the battlefield. The Army referred to the system as the AN/MYK-1, or AN/MYK-2 for the dual-CPU version, Sylvania later offered a commercial version as the S 9400.
History
In early 1956 the Army Signal Corps at Fort Monmouth released a contract tender for the development of a van-mounted mobile computer as part of their Fieldata efforts. Fieldata envisioned a system where any sort of reports would be converted into text format and then sent electronically around an extended battlefield. At the recipient's end, it would be converted into an appropriate output, often on a line printer or similar device. By automating the process of routing the messages in the middle of the information flow, the Signal Corps was hoping to guarantee delivery and improve responsiveness. Fieldata can be thought of as a general purpose version of the system the US Air Force was developing in their SAGE system, which did the same task but limited to the field of information about aircraft locations and status.
The heart of Fieldata would be computer systems that would receive, store, prioritize and send the messages. The machines would have to be built using transistors in order to meet the size and power requirements, so in effect, the Army was paying to develop transistorized computers. In spite of this, most established players ignored the Army's calls for the small machine. Sylvania's director of development speculated that the Army's terminology in the contract may have hidden the apparent wonderful opportunity. In the end, RCA and Sylvania entered bids, along with a number of smaller companies with unproven track records. Sylvania's bid was the lower of the "big two", and they won the contract in September 1956.
The first experimental machine, retroactively known as MOBIDIC A, was delivered to Fort Monmouth in December 1959. By this time the Army had expressed increasing interest in the concept and had ordered four additional machines and associated software, including a COBOL compiler. The original contract for the experimental machine was for $1.6 million, but the new developments increased the total to between $20 and $30 million.
MOBIDIC B was supplied to the Army's Tactical Operations Center and featured dual CPUs for increased reliability.
MOBIDIC A/B weighed about .
MOBIDIC C was sent to Fort Huachuca as a software testing system. MOBIDIC D was ordered for the Army Security Agency in Europe, and MOBIDIC 7A was shipped to the 7th Army Stock Control Center i |
https://en.wikipedia.org/wiki/Fieldata | FIELDATA (also written as Fieldata) was a pioneering computer project run by the US Army Signal Corps in the late 1950s that intended to create a single standard (as defined in MIL-STD-188A/B/C) for collecting and distributing battlefield information. In this respect it could be thought of as a generalization of the US Air Force's SAGE system that was being created at about the same time.
Unlike SAGE, FIELDATA was intended to be much larger in scope, allowing information to be gathered from any number of sources and forms. Much of the FIELDATA system was the specifications for the format the data would take, leading to a character set that would be a huge influence on ASCII a few years later. FIELDATA also specified the message formats and even the electrical standards for connecting FIELDATA-standard machines together.
Another part of the FIELDATA project was the design and construction of computers at several different scales, from data-input terminals at one end, to theatre-wide data processing centers at the other. Several FIELDATA-standard computers were built during the lifetime of the project, including the transportable MOBIDIC from Sylvania, and the BASICPAC and LOGICPAC from Philco. Another system, ARTOC, was intended to provide graphical output (in the form of photographic slides), but was never completed.
Because FIELDATA did not specify codes for interconnection and data transmission control, different systems (like "STANDARD FORM", "COMLOGNET Common language code", "SACCOMNET (465L) Control Code") used different control functions. Intercommunication between them was difficult.
FIELDATA is the original character set used internally in UNIVAC computers of the 1100 series, each six-bit character contained in six sequential bits of the 36-bit word of that computer. The direct successor to the UNIVAC 1100 is the Unisys 2200 series computers, which used FIELDATA (although ASCII is now also common with each character encoded in 1/4 of a word, or 9 bits). Because some of the FIELDATA characters are not represented in ASCII, the Unisys 2200 uses '^', '"' and '_' characters for codes 004oct, 076oct and 077oct respectively.
The FIELDATA project ran from 1956 until it was stopped during a reorganization in 1962.
FIELDATA characters
Military
UNIVAC
The code version used on the UNIVAC was based on the second half (primary code) of the military version with some changes.
Character map
Military version
The following table is representative of a reference version of the military set, as described in . Various other variants exist, with in some cases dramatic differences in the supervisory code (the first four rows 0–3). The letters in the first two rows are intended for use in "alphabetic supervisory information".
UNIVAC version
The code version used on the UNIVAC was based on the second half (6-bit primary code) of the military version with some changes.
Footnotes
References and further reading
Character sets
Early c |
https://en.wikipedia.org/wiki/Modified%20frequency%20modulation | Modified frequency modulation (MFM) is a run-length limited (RLL) line code used to encode data on most floppy disks and some hard disk drives. It was first introduced on hard disks in 1970 with the IBM 3330 and then in floppy disk drives beginning with the IBM 53FD in 1976.
MFM is a modification to the original frequency modulation encoding (FM) code specifically for use with magnetic storage. MFM allowed devices to double the speed data was written to the media as the code guaranteed only one polarity change per encoded data bit. For this reason, MFM disks are typically known as "double density" while the earlier FM became known as "single density".
MFM is used with a data rate of 250–500 kbit/s (500–1000 kbit/s encoded) on industry-standard -inch and -inch ordinary and high-density floppy diskettes. MFM was also used in early hard disk designs, before the advent of more efficient types of RLL codes. Outside of niche applications, MFM encoding is obsolete in magnetic recording.
Magnetic storage
Magnetic storage devices, like hard drives and magnetic tape, store data not as absolute values, but in the changes in polarity. This is because a changing magnetic field will induce an electrical current in a nearby wire, and vice versa. By sending a series of changing currents to the read/write head while the media moves past it, the result will be a pattern of magnetic polarities on the media that change where the data was a "1". The exact nature of the media determines how many of these changes can occur within a given surface area, and when this is combined with the nominal speed of movement, it produces the maximum data rate for that system.
Disk drives are subject to a variety of mechanical and materials effects that cause the original pattern of data to "jitter" in time. If a long string of "0" are sent to disk, there is nothing to indicate which bit a following "1" might belong to - due to the effects of jitter it may become misplaced in time. Re-aligning the signals on the disk with individual data bits requires some sort of timing encoded to the disk along with the data.
A diverse range of suitable encodings, known generally as line codes, have been developed for this purpose. Their suitability depends on the media or transmission mechanism being used.
Frequency modulation
Frequency modulation encoding (FM) was the first widely used system to perform this operation. The drive controller includes an accurate clock running at half the selected data rate of the disk media. When data is written to the disk, the clock signal is interleaved with the data. On reading, the clock signals are used as short-term triggers to time the presence or lack of a following signal that represents the data bits.
The upside to the FM approach is that it is extremely easy to implement the writing circuity and the clock recovery on reading is also relatively simple. The downside is that it uses up half of the disk surface for the clock signal, thus halving the |
https://en.wikipedia.org/wiki/Madhu%20Sudan | Madhu Sudan (born 12 September 1966) is an Indian-American computer scientist. He has been a Gordon McKay Professor of Computer Science at the Harvard John A. Paulson School of Engineering and Applied Sciences since 2015.
Career
He received his bachelor's degree in computer science from IIT Delhi in 1987 and his doctoral degree in computer science at the University of California, Berkeley in 1992. He was a research staff member at the IBM Thomas J. Watson Research Center in Yorktown Heights, New York from 1992 to 1997 and moved to MIT after that. From 2009 to 2015 he was a permanent researcher at Microsoft Research New England before joining Harvard University in 2015.
Research contribution and awards
He was awarded the Rolf Nevanlinna Prize at the 24th International Congress of Mathematicians (ICM) in 2002. The prize recognizes outstanding work in the mathematical aspects of computer science. Sudan was honored for his work in advancing the theory of probabilistically checkable proofs—a way to recast a mathematical proof in computer language for additional checks on its validity—and developing error-correcting codes. For the same work, he received the ACM's Distinguished Doctoral Dissertation Award in 1993 and the Gödel Prize in 2001 and was an Invited Speaker of the ICM in 1998. He is a Fellow of the ACM (2008). In 2012 he became a fellow of the American Mathematical Society. In 2014 he won the Infosys Prize in the mathematical sciences.
In 2017 he was elected to the National Academy of Sciences.
In 2021, he was awarded the IEEE Richard W. Hamming Medal for 2022.
Sudan has made important contributions to several areas of theoretical computer science, including probabilistically checkable proofs, non-approximability of optimization problems, list decoding, and error-correcting codes.
References
External links
DBLP: Madhu Sudan
Madhu Sudan's Home Page
Bio from the Microsoft Research New England page
1966 births
Living people
Indian computer scientists
Indian emigrants to the United States
American computer scientists
Theoretical computer scientists
20th-century Indian mathematicians
University of California, Berkeley alumni
Massachusetts Institute of Technology faculty
Gödel Prize laureates
Nevanlinna Prize laureates
American people of Indian Tamil descent
Fellows of the Association for Computing Machinery
Fellows of the American Mathematical Society
IIT Delhi alumni
Scientists from Chennai
American academics of Indian descent
Members of the United States National Academy of Sciences
Harvard John A. Paulson School of Engineering and Applied Sciences faculty
Simons Investigator |
https://en.wikipedia.org/wiki/Health%20Level%207 | Health Level Seven or HL7 is a range of global standards for the transfer of clinical and administrative health data between applications. The HL7 standards focus on the application layer, which is "layer 7" in the Open Systems Interconnection model. The standards are produced by Health Level Seven International, an international standards organization, and are adopted by other standards issuing bodies such as American National Standards Institute and International Organization for Standardization. There are a range of primary standards that are commonly used across the industry, as well as secondary standards which are less frequently adopted.
Purpose
Health organizations typically have many different computer systems used to process different patient administration or clinical tasks, such as billing, medication management, patient tracking, and documentation. All of these systems should communicate, or "interface", with each other when they receive new information or when they wish to retrieve information. HL7 International specifies a number of flexible standards, guidelines, and methodologies by which these healthcare systems can communicate with each other. The standards allow for easier 'interoperability' of healthcare data as it is shared and processed uniformly and consistently by the different systems. This allows clinical and non-clinical data to be shared more easily, theoretically improving patient care and health system performance.
Primary standards
HL7 International considers the following standards to be its primary standards – those standards that are most commonly used and implemented:
Version 2.x Messaging Standard – an interoperability specification for health and medical transactions
Version 3 Messaging Standard – an interoperability specification for health and medical transactions
Clinical Document Architecture (CDA) – an exchange model for clinical documents, based on HL7 Version 3
Continuity of Care Document (CCD) – a US specification for the exchange of medical summaries, based on CDA.
Structured Product Labeling (SPL) – the published information that accompanies a medicine, based on HL7 Version 3
Clinical Context Object Workgroup (CCOW) – an interoperability specification for the visual integration of user applications
Other HL7 standards/methodologies include:
Fast Healthcare Interoperability Resources (FHIR) – a standard for the exchange of resources
Arden Syntax – a grammar for representing medical conditions and recommendations as a Medical Logic Module (MLM)
Claims Attachments – a Standard Healthcare Attachment to augment another healthcare transaction
Functional Specification of Electronic Health Record (EHR) and Personal Health Record (PHR) systems – a standardized description of health and medical functions sought for or available in such software applications
GELLO – a standard expression language used for clinical decision support
Version 2 messaging
The HL7 version 2 standard (also known as |
https://en.wikipedia.org/wiki/C%2B%2B%20Standard%20Library | In the C++ programming language, the C++ Standard Library is a collection of classes and functions, which are written in the core language and part of the C++ ISO Standard itself.
Overview
The C++ Standard Library provides several generic containers, functions to use and manipulate these containers, function objects, generic strings and streams (including interactive and file I/O), support for some language features, and functions for common tasks such as finding the square root of a number. The C++ Standard Library also incorporates most headers of the ISO C standard library ending with ".h", but their use was deprecated (reverted the deprecation since C++23). C++23 instead considers these headers as useful for interoperability with C, and recommends against their usage outside of programs that are intended to be both valid C and C++ programs. No other headers in the C++ Standard Library end in ".h". Features of the C++ Standard Library are declared within the std namespace.
The C++ Standard Library is based upon conventions introduced by the Standard Template Library (STL), and has been influenced by research in generic programming and developers of the STL such as Alexander Stepanov and Meng Lee. Although the C++ Standard Library and the STL share many features, neither is a strict superset of the other.
A noteworthy feature of the C++ Standard Library is that it not only specifies the syntax and semantics of generic algorithms, but also places requirements on their performance. These performance requirements often correspond to a well-known algorithm, which is expected but not required to be used. In most cases this requires linear time O(n) or linearithmic time O(n log n), but in some cases higher bounds are allowed, such as quasilinear time O(n log2 n) for stable sort (to allow in-place merge sort). Previously, sorting was only required to take O(n log n) on average, allowing the use of quicksort, which is fast in practice but has poor worst-case performance, but introsort was introduced to allow both fast average performance and optimal worst-case complexity, and as of C++11, sorting is guaranteed to be at worst linearithmic. In other cases requirements remain laxer, such as selection, which is only required to be linear on average (as in quickselect), not requiring worst-case linear as in introselect.
The C++ Standard Library underwent ISO standardization as part of the C++ ISO Standardization effort in the 1990s. Since 2011, it has been expanded and updated every three years with each revision of the C++ standard.
Implementations
Discontinued
Apache C++ Standard Library
The Apache C++ Standard Library is another open-source implementation. It was originally developed commercially by Rogue Wave Software and later donated to the Apache Software Foundation. However, after more than five years without a release, the board of the Apache Software Foundation decided to end this project and move it to Apache Attic.
See also
The following |
https://en.wikipedia.org/wiki/C%20dynamic%20memory%20allocation | C dynamic memory allocation refers to performing manual memory management for dynamic memory allocation in the C programming language via a group of functions in the C standard library, namely , , , and .
The C++ programming language includes these functions; however, the operators and provide similar functionality and are recommended by that language's authors. Still, there are several situations in which using new/delete is not applicable, such as garbage collection code or performance-sensitive code, and a combination of malloc and placement new may be required instead of the higher-level new operator.
Many different implementations of the actual memory allocation mechanism, used by , are available. Their performance varies in both execution time and required memory.
Rationale
The C programming language manages memory statically, automatically, or dynamically. Static-duration variables are allocated in main memory, usually along with the executable code of the program, and persist for the lifetime of the program; automatic-duration variables are allocated on the stack and come and go as functions are called and return. For static-duration and automatic-duration variables, the size of the allocation must be compile-time constant (except for the case of variable-length automatic arrays). If the required size is not known until run-time (for example, if data of arbitrary size is being read from the user or from a disk file), then using fixed-size data objects is inadequate.
The lifetime of allocated memory can also cause concern. Neither static- nor automatic-duration memory is adequate for all situations. Automatic-allocated data cannot persist across multiple function calls, while static data persists for the life of the program whether it is needed or not. In many situations the programmer requires greater flexibility in managing the lifetime of allocated memory.
These limitations are avoided by using dynamic memory allocation, in which memory is more explicitly (but more flexibly) managed, typically by allocating it from the an area of memory structured for this purpose. In C, the library function malloc is used to allocate a block of memory on the heap. The program accesses this block of memory via a pointer that malloc returns. When the memory is no longer needed, the pointer is passed to free which deallocates the memory so that it can be used for other purposes.
The original description of C indicated that calloc and cfree were in the standard library, but not malloc. Code for a simple model implementation of a storage manager for Unix was given with alloc and free as the user interface functions, and using the sbrk system call to request memory from the operating system. The 6th Edition Unix documentation gives alloc and free as the low-level memory allocation functions. The malloc and free routines in their modern form are completely described in the 7th Edition Unix manual.
Some platforms provide library or intrinsic func |
https://en.wikipedia.org/wiki/ESER | ESER is an abbreviation for Einheitliches System Elektronischer Rechenmaschinen (German for standardized system of electronic computers), a term used in the GDR for ES EVM computers produced according to a treaty between the members of Comecon signed on December 23, 1968 covering the development of a standardized computing system.
ESER was also the name for computers developed by this standard. Most ESER Computers were named ЕС (which is Cyrillic for "ES") followed by a four digit number, e.g., EC 1055, often also called ESER (e.g., ESER 1055). Robotron also produced minicomputers, whose names started with "K" (Kleinrechner for "minicomputer").
The ESER systems were in operation in GDR and later in the new states of Germany until 1995.
GDR manufacturing
Robotron
EC 1834, 1835 (IBM PC XT compatibles)
EC 1040, 1055, 1055M, 1056, 1057
EC 7927
K 1001, 1002, 1003, K 1510, K 1520, K 1820, K 5103, K 5201, K 8913, K 8915, K 8924
CM 1910
Hungarian manufacturing
Videoton
EC 1010, 1011, 1012
See also
History of computer hardware in Eastern Bloc countries
External links
Technical data of some ESER computers by Robotron
Technical data of some ESER computers by Videoton
Some photos of a ESER Mainframe
Overview of different ESER Mainframes in German (page 6, PDF)
Overview of different ESER Computers in Russian (with pictures)
Computer standards
Eastern Bloc
Comecon |
https://en.wikipedia.org/wiki/BBC%20UKTV | BBC UKTV is an Australian pay television channel in Australia and New Zealand, screening British entertainment programming, sourced mainly from the archives of the BBC, RTL Group (mainly Talkback Thames material) and ITV plc. The channel was originally a joint venture with Foxtel (60% ownership), the RTL Group (20% ownership) and BBC Worldwide (20% ownership). It is now owned solely by BBC Studios. It is the home of the channel's flagship programme The Graham Norton Show.
History
The channel was first launched in Australia in August 1996, becoming available on Austar in April 1999 and on Optus in December 2002. A New Zealand version with different programming launched on Sky TV, in November 2003.
It shows a mix of repeats of old UK shows previously screened in Australia or New Zealand and new episodes of programs not shown before in Australia or New Zealand. Repeated series include Doctor Who, Hitchhiker's Guide to the Galaxy, Are You Being Served?, Dad's Army, Torchwood, Torchwood Declassified, The Jewel in the Crown, Never the Twain, The Sweeney, and The Bill that have already been seen on free-to-air terrestrial television in Australia. New series include Shameless, new episodes of popular soap operas Coronation Street and EastEnders and the original UK version of The Weakest Link which have not otherwise been screened in Australia. UK soap opera Family Affairs, which has never been screened on free-to-air Australian television, ran on UKTV from 1998 to 2007. In July 2006 UKTV began screening 2006 episodes of UK soap opera Emmerdale which had never before been screened in Australia.
UKTV's episodes of EastEnders are currently two weeks behind the United Kingdom, and Coronation Street is about one week behind. Current Emmerdale episodes currently in 2021 are about four weeks behind the original UK broadcasts.
In addition to British programming UKTV has repeated Australian soap operas Sons and Daughters and Prisoner which were both produced by the Reg Grundy Organisation (now owned by FremantleMedia). In both cases the entire series was shown; the Sons and Daughters repeat run was from 1997 until 2000 and Prisoner ran from 1997 until October 2004, Prisoner is now screening on 111 Hits from March 2011. It also screened the TVNZ soap opera Shortland Street for several years in the 1990s, after early episodes of that series had briefly been screened by SBS on free-to-air television in Australia.
In Australia, UKTV, like all pay TV drama channels, is legally required to spend 10 per cent of its total program expenditure on funding new eligible (Australian and New Zealand) drama programs. Such productions include Changi, Supernova, Make or Break and False Witness.
UKTV has separate services in Australia and New Zealand, partly to reflect different local tastes, but also for rights reasons, as many programmes are shown on free-to-air channels in New Zealand. For example, Coronation Street has been shown on TVNZ 1 for many years, while until Ma |
https://en.wikipedia.org/wiki/Lilith%20%28computer%29 | The DISER Lilith is a custom built workstation computer based on the Advanced Micro Devices (AMD) 2901 bit slicing processor, created by a group led by Niklaus Wirth at ETH Zürich. The project began in 1977, and by 1984 several hundred workstations were in use. It has a high resolution full page portrait oriented cathode ray tube display, a mouse, a laser printer interface, and a computer networking interface. Its software is written fully in Modula-2 and includes a relational database program named Lidas.
The Lilith processor architecture is a stack machine. Citing from Sven Erik Knudsen's contribution to "The Art of Simplicity": "Lilith's clock speed was around 7 MHz and enabled Lilith to execute between 1 and 2 million instructions (called M-code) per second. (...) Initially, the main memory was planned to have 65,536 16-bit words memory, but soon after its first version, it was enlarged to twice that capacity. For regular Modula-2 programs however, only the initial 65,536 words were usable for storage of variables."
History
The development of Lilith was influenced by the Xerox Alto from the Xerox PARC (1973) where Niklaus Wirth spent a sabbatical from 1976 to 1977. Unable to bring back one of the Alto systems to Europe, Wirth decided to build a new system from scratch between 1978 and 1980, selling it under the company name DISER (Data Image Sound Processor and Emitter Receiver System). In 1985, he had a second sabbatical leave to PARC, which led to the design of the Oberon System. Ceres, the follow-up to Lilith, was released in 1987.
Operating system
The Lilith operating system (OS), named Medos-2, was developed at ETH Zurich, by Svend Erik Knudsen with advice from Wirth. It is a single user, object-oriented operating system built from modules of Modula-2.
Its design influenced design of the OS Excelsior, developed for the Soviet Kronos workstation (see below), by the Kronos Research Group (KRG).
Soviet variants
From 1986 into the early 1990s, Soviet Union technologists created and produced a line of printed circuit board systems, and workstations based on them, all named Kronos. The workstations were based on Lilith, and made in small numbers.
Mouse
The computer mouse of the Lilith was custom-designed, and later used with the Smaky computers. It then inspired the first mice produced by Logitech.
References
External links
Documentation on BitSavers
Geissman, L et al. (August 1982) Lilith Handbook
Wirth, N (1981) The Personal Computer Lilith
Emulith emulator for the Lilith, homepage and documentation
Lilith and Modula-2
ETHistory - Lilith Workstation
AMD AM2901DC entry on CPU World
Computer workstations
Computers using bit-slice designs
High-level language computer architecture |
https://en.wikipedia.org/wiki/Open%20Sound%20Control | Open Sound Control (OSC) is a protocol for networking sound synthesizers, computers, and other multimedia devices for purposes such as musical performance or show control. OSC's advantages include interoperability, accuracy, flexibility and enhanced organization and documentation. Its disadvantages include inefficient coding of information, increased load on embedded processors, and lack of standardized messages/interoperability. The first specification was released in March 2002.
Motivation
OSC is a content format developed at CNMAT by Adrian Freed and Matt Wright comparable to XML, WDDX, or JSON. It was originally intended for sharing music performance data (gestures, parameters and note sequences) between musical instruments (especially electronic musical instruments such as synthesizers), computers, and other multimedia devices. OSC is sometimes used as an alternative to the 1983 MIDI standard, when higher resolution and a richer parameter space is desired. OSC messages are transported across the internet and within local subnets using UDP/IP and Ethernet. OSC messages between gestural controllers are usually transmitted over serial endpoints of USB wrapped in the SLIP protocol.
Features
OSC's main features, compared to MIDI, include:
Open-ended, dynamic, URI-style symbolic naming scheme
Symbolic and high-resolution numeric data
Pattern matching language to specify multiple recipients of a single message
High resolution time tags
"Bundles" of messages whose effects must occur simultaneously
Applications
There are dozens of OSC applications, including real-time sound and media processing environments, web interactivity tools, software synthesizers, programming languages and hardware devices. OSC has achieved wide use in fields including musical expression, robotics, video performance interfaces, distributed music systems and inter-process communication.
The TUIO community standard for tangible interfaces such as multitouch is built on top of OSC. Similarly the GDIF system for representing gestures integrates OSC.
OSC is used extensively in experimental musical controllers, and has been built into several open source and commercial products.
The Open Sound World (OSW) music programming language is designed around OSC messaging.
OSC is the heart of the DSSI plugin API, an evolution of the LADSPA API, in order to make the eventual GUI interact with the core of the plugin via messaging the plugin host. LADSPA and DSSI are APIs dedicated to audio effects and synthesizers.
In 2007, a standardized namespace within OSC called SYN, for communication between controllers, synthesizers and hosts, was proposed,
Notable software with OSC implementations include:
Notable hardware with OSC implementations include:
Design
OSC messages consist of an address pattern (such as /oscillator/4/frequency), a type tag string (such as ,fi for a float32 argument followed by an int32 argument), and the arguments themselves (which may include a time ta |
https://en.wikipedia.org/wiki/OSC | OSC may refer to:
Organizations
Odborové sdružení československé, the Czechoslovak Trade Union Association
Office of Special Counsel (in the United States of America)
Ohio Supercomputer Center, a computing research facility in Columbus
Onslow County Schools, a school district in Onslow County, North Carolina
Ontario Science Centre, a science museum in Toronto, Canada
Ontario Securities Commission, a securities regulatory agency
Open Source Center, a United States government center that provides analysis of open-source intelligence
Open Source Consortium, The UK Open Source trade association
Orbital Sciences Corporation, a satellite-oriented company
Order of Saint Clare, a Religious Order founded by Clare of Assisi whose members use the post-nominal letters O.S.C.
Ordo Sanctae Crucis or Canons Regular of the Order of the Holy Cross, a Roman Catholic religious order commonly called Crosiers
Orlando Science Center, a science-education establishment in Florida
Overseas School of Colombo, a multinational English medium international school located in Colombo, Sri Lanka.
Computing
Open Sound Control, a music-oriented electronic communications protocol used in computers and multimedia devices
openSUSE Command-line tool, a command-line tool used for openSUSE build service
Orthogonal signal correction, a spectral preprocessing technique
Operating system command, one of the C0 and C1 control codes
Optical Signature Code, an industry standard format for LWIR signatures.
Other
Off-site construction, a mode of construction
Osceola (Amtrak station), Iowa, United States; Amtrak station code OSC
Orson Scott Card, author of speculative fiction
Organic solar cell
Oscoda–Wurtsmith Airport (IATA code) - Michigan, United States
Order to show cause |
https://en.wikipedia.org/wiki/Dennis%20Hayes%20%28businessman%29 | Dennis C. Hayes (born 1950) is the inventor of PC modem and founder of Hayes Microcomputer Products, a manufacturer of modems mostly known for introducing the Hayes AT command set, which has subsequently been used in most modems produced to this day.
Background
Hayes had a student job at AT&T Long Lines, in an engineering group, while attending Georgia Institute of Technology.
He left Georgia Tech in the mid-1970s to work at an early data communications company, National Data Corporation in Atlanta, a company that handled electronic money transfers and credit card authorizations. Hayes' job was to set up modem connections for NDC's customers. In 1977, Hayes started his company "by assembling modems by hand on a borrowed kitchen table." He met Dale Heatherington (born 1948) at National Data Corporation and together they developed and marketed the first high-quality IBM PC modem, and built the company named Hayes Communications around it. While Heatherington left the company early (in 1985) to retire, Hayes ran the company until it filed for bankruptcy in 1998 when the technology was incorporated into the products of competitors.
In 1994, Hayes' share of the modem market was 20% and still "the market leader in modems", but a decline in relation to its previous market share of over 50%.
Personal life
In 1982, Hayes married Melita Easters. They divorced in 1987 with an estimated $40 million divorce settlement, one of the largest ever in Georgia. The same year of his divorce, Hayes married Mina Chan with whom, according to Georgia Trend magazine, he had an affair in 1986 while still married to Easters. Chan was a director of Hayes's company. From two marriages he has four children.
References
1950 births
20th-century American businesspeople
American computer businesspeople
Businesspeople in information technology
American company founders
Georgia Tech alumni
Living people
Hayes Microcomputer Products |
https://en.wikipedia.org/wiki/Free-form%20language | In computer programming, a free-form language is a programming language in which the positioning of characters on the page in program text is insignificant. Program text does not need to be placed in specific columns as on old punched card systems, and frequently ends of lines are insignificant. Whitespace characters are used only to delimit tokens, and have no other significance.
Most free-form languages descend from ALGOL, including C, Pascal, and Perl. Lisp languages are free-form, although they do not descend from ALGOL. Rexx is mostly free-form, though in some cases whitespace characters are concatenation operators. SQL, though not a full programming language, is also free-form.
Most free-form languages are also structured programming languages, which is sometimes thought to go along with the free-form syntax: Earlier imperative programming languages such as Fortran 77 used particular columns for line numbers, which many structured languages do not use or need.
Structured languages exist which are not free-form, such as ABC, Curry, Haskell, Python and others. Many of these use some variant of the off-side rule, in which indentation, rather than keywords or braces, is used to group blocks of code.
See also
Indent style
Obfuscated code
Curly-bracket programming language Many free-form languages are within this set.
Programming language classification |
https://en.wikipedia.org/wiki/Andrew%20Morton%20%28computer%20programmer%29 | Andrew Keith Paul Morton (born 1959) is an Australian software engineer, best known as one of the lead developers of the Linux kernel. He is currently a co-maintainer of the Ext3 file system, the journaling layer for block devices (JBD) and Memory Management.
In the late 1980s, he was one of the partners of a company in Sydney, Australia that produced a kit computer called the Applix 1616, as well as a hardware engineer for the (now-defunct) Australian gaming equipment manufacturer Keno Computer Systems. He holds an honours degree in electrical engineering from the University of New South Wales in Australia.
Morton maintains a Linux kernel patchset known as the mm tree, which contains work-in-progress patches that might later be accepted into the official Linux tree maintained by Linus Torvalds. "mm" as a primary testing ground became unmanageably large and busy, and in 2008 the "linux-next" tree was created to fill much of this role.
In 2001, Andrew Morton and his family moved from Wollongong, New South Wales to Palo Alto, California.
In July 2003, Morton joined the Open Source Development Labs under an agreement with his then-employer Digeo Inc. (makers of the Moxi home entertainment media center), in which OSDL supported Morton's Linux kernel development work while he continued in his official role as principal engineer at Digeo.
Since August 2006, Morton has been employed by Google and continues his current work in maintaining the kernel.
Andrew Morton delivered the keynote speech at the 2004 Ottawa Linux Symposium. He was also a featured speaker at MontaVista Software's Vision 2007 Conference.
He was an expert witness in the SCO v. IBM lawsuit contesting UNIX copyrights.
Andrew is also known by his username akpm, as found in e-mail addresses and as part of the URL to his now-defunct webpage. On being asked what the initials KP stood for, he replied, "Some say 'Kernel Programmer.' My parents said 'Keith Paul.'"
References
External links
Interview: Andrew Morton; Jeremy Andrews; Kerneltrap; February 14, 2002.
Interview; Nadia Cameron; LinuxWorld; July 16, 2003.
Keynote speech; Ottawa Linux Symposium, 2004
Interview ; Ingrid Marson; ZDNet UK; May 5, 2006.
Interview; Fosdem Conference; Feb 06, 2007.
Audio of Talk at SDForum
Video with Andrew Morton at Hannover Industry Trade Fair, Germany, May 2008
Link to his patches
Link to his own kernel tree
Archive of his now-defunct webpage, hosted by Internet Archive
1959 births
Australian computer programmers
Free software programmers
Google employees
Linux kernel programmers
Living people |
https://en.wikipedia.org/wiki/Virtual%20address%20%28disambiguation%29 | Virtual address refers to an address identifying a virtual, i.e. non-physical, entity. For example:
Virtual address space in computing
Virtual address translation to physical address in computing
Virtual postal address, see virtual mailbox or commercial mail receiving agency
Virtual business address, see Virtual office
See also
Virtual (disambiguation) |
https://en.wikipedia.org/wiki/Substitution%E2%80%93permutation%20network | In cryptography, an SP-network, or substitution–permutation network (SPN), is a series of linked mathematical operations used in block cipher algorithms such as AES (Rijndael), 3-Way, Kalyna, Kuznyechik, PRESENT, SAFER, SHARK, and Square.
Such a network takes a block of the plaintext and the key as inputs, and applies several alternating rounds or layers of substitution boxes (S-boxes) and permutation boxes (P-boxes) to produce the ciphertext block. The S-boxes and P-boxes transform of input bits into output bits. It is common for these transformations to be operations that are efficient to perform in hardware, such as exclusive or (XOR) and bitwise rotation. The key is introduced in each round, usually in the form of "round keys" derived from it. (In some designs, the S-boxes themselves depend on the key.)
Decryption is done by simply reversing the process (using the inverses of the S-boxes and P-boxes and applying the round keys in reversed order).
Components
An S-box substitutes a small block of bits (the input of the S-box) by another block of bits (the output of the S-box). This substitution should be one-to-one, to ensure invertibility (hence decryption). In particular, the length of the output should be the same as the length of the input (the picture on the right has S-boxes with 4 input and 4 output bits), which is different from S-boxes in general that could also change the length, as in Data Encryption Standard (DES), for example. An S-box is usually not simply a permutation of the bits. Rather, a good S-box will have the property that changing one input bit will change about half of the output bits (or an avalanche effect). It will also have the property that each output bit will depend on every input bit.
A P-box is a permutation of all the bits: it takes the outputs of all the S-boxes of one round, permutes the bits, and feeds them into the S-boxes of the next round. A good P-box has the property that the output bits of any S-box are distributed to as many S-box inputs as possible.
At each round, the round key (obtained from the key with some simple operations, for instance, using S-boxes and P-boxes) is combined using some group operation, typically XOR.
Properties
A single typical S-box or a single P-box alone does not have much cryptographic strength: an S-box could be thought of as a substitution cipher, while a P-box could be thought of as a transposition cipher. However, a well-designed SP network with several alternating rounds of S- and P-boxes already satisfies Shannon's confusion and diffusion properties:
The reason for diffusion is the following: If one changes one bit of the plaintext, then it is fed into an S-box, whose output will change at several bits, then all these changes are distributed by the P-box among several S-boxes, hence the outputs of all of these S-boxes are again changed at several bits, and so on. Doing several rounds, each bit changes several times back and forth, therefore, by the end, t |
https://en.wikipedia.org/wiki/ISO/IEC%2011404 | ISO/IEC 11404, General Purpose Datatypes (GPD), are a collection of datatypes defined independently of any particular programming language or implementation. These datatypes can be used to describe interfaces to existing libraries without having to specify the language (such as Fortran or C).
The first edition of this standard was published in 1996 under the title "Language-independent datatypes". The standard was revised by the responsible ISO sub-committee (JTC1/SC22 - Information Technology - Programming languages). The revised version has the new title "General Purpose Datatypes".
External links
ISO/IEC 11404:2007, complete text of General purpose datatypes.
Data types
11404 |
https://en.wikipedia.org/wiki/Inverse%20scattering%20problem | In mathematics and physics, the inverse scattering problem is the problem of determining characteristics of an object, based on data of how it scatters incoming radiation or particles. It is the inverse problem to the direct scattering problem, which is to determine how radiation or particles are scattered based on the properties of the scatterer.
Soliton equations are a class of partial differential equations which can be studied and solved by a method called the inverse scattering transform, which reduces the nonlinear PDEs to a linear inverse scattering problem. The nonlinear Schrödinger equation, the Korteweg–de Vries equation and the KP equation are examples of soliton equations. In one space dimension the inverse scattering problem is equivalent to a Riemann-Hilbert problem. Since its early statement for radiolocation, many applications have been found for inverse scattering techniques, including echolocation, geophysical survey, nondestructive testing, medical imaging, quantum field theory.
References
.
Inverse Acoustic and Electromagnetic Scattering Theory; Colton, David and Kress, Rainer
Scattering theory
Scattering, absorption and radiative transfer (optics)
Inverse problems |
https://en.wikipedia.org/wiki/Famous%20Idaho%20Potato%20Bowl | The Famous Idaho Potato Bowl, previously the Humanitarian Bowl (1997–2003, 2007–2010) and the MPC Computers Bowl (2004–2006), is an NCAA-sanctioned post-season college football bowl game that has been played annually since 1997 at Albertsons Stadium on the campus of Boise State University in Boise, Idaho. The game is televised nationally on the ESPN family of networks. Cincinnati defeated Utah State in the inaugural game in 1997.
History
Conference tie-ins
The Humanitarian Bowl was launched, in part, as a response to changes made to the Las Vegas Bowl’s selection process. When the bowl was launched in 1992 as the successor to the California Bowl, it inherited the bowl’s contracted matchup of the champions of the Big West Conference and the Mid-American Conference (MAC) that had been taking place since 1982. However, after the 1996 edition, the Las Vegas Bowl dropped its affiliations with the Big West and the MAC in favor of offering a bid to a team from the Western Athletic Conference (WAC), forcing the conferences to find other solutions. This resulted in two new bowl games being launched for the 1997 season, one of which was awarded to Boise and initially named the Humanitarian Bowl. The Big West, which had Boise State as a member at the time, agreed to terms to send its champion to the bowl. The MAC, meanwhile, sent its champion to the Motor City Bowl in Detroit.
From 1997 to 1999, the Big West champion was matched with a team from Conference USA (C-USA), while in 2000 the WAC sent a representative. The Big West stopped sponsoring football after the 2000 season, and bowl organizers extended a permanent invite to the WAC to replace the Big West as host of the game, and struck an agreement with the Atlantic Coast Conference (ACC) to provide a bowl-eligible team if it had yet to fill its bowl allotment. The WAC champion received the automatic bid to the game unless that team received a better offer from another bowl game or qualified for the Bowl Championship Series (BCS).
The WAC and ACC met in the 2001 through 2008 editions of the bowl, except for 2002 when the ACC's slot was filled by Iowa State of the Big 12 Conference. In 2009, the Mountain West Conference was to provide a team, but Mountain West champion TCU was selected for the Fiesta Bowl and the conference did not have enough bowl-eligible teams to send a replacement; as a result, Bowling Green of the MAC was invited. In 2010, the bowl inherited the MAC's International Bowl tie-in after that Toronto-based bowl folded; the bowl featured a MAC vs. WAC matchup through 2012.
After the WAC stopped sponsoring football in 2012, Mountain West inherited its spot as host, reaching agreement with the bowl to provide a team, starting with the December 2013 edition. The bowl featured MAC vs. Mountain West matchups in the 2013 through 2015 games. In 2016, the bowl invited in-state Idaho of the Sun Belt Conference in place of a MAC team. The 2017 edition returned to MAC vs. Mountain West, while in |
https://en.wikipedia.org/wiki/Luc%20Steels | Luc Steels (born in 1952) is a Belgian scientist and artist. Steels is considered a pioneer of Artificial Intelligence in Europe who has made contributions to expert systems, behavior-based robotics, artificial life and evolutionary computational linguistics. He was a fellow of the Catalan Institution for Research and Advanced Studies ICREA associated as a research professor with the Institute for Evolutionary Biology (UPF/CSIC) in Barcelona. He was formerly founding Director of the Artificial Intelligence Laboratory of the Vrije Universiteit Brussel and founding director of the Sony Computer Science Laboratory in Paris. Steels has also been active in the arts collaborating with visual artists and theater makers and composing music for opera.
Biography
Steels obtained a master's degree in Computer Science at MIT, specializing in AI under the supervision of Marvin Minsky and Carl Hewitt. He obtained a Ph.D. at the University of Antwerp with a thesis in computational linguistics on a parallel model of parsing. In 1980, he joined the Schlumberger-Doll Research Laboratory in Ridgefield (US) to work on knowledge-based approaches to the interpretation of oil well logging data and became leader of the group who developed the Dipmeter Advisor which he transferred into industrial use while at Schlumberger Engineering, Clamart (Paris). In 1983, he was appointed tenured professor in Computer Science with a chair in AI at the Free University of Brussels (VUB). The same year he founded the VUB Artificial Intelligence Laboratory and became the first chairman of the VUB Computer Science Department from 1990 to 1995. The VUB AI Lab focused initially on knowledge-based systems for various industrial applications (equipment diagnosis, transport scheduling, design) but gradually focused more on basic research in AI, moving at the cutting edge of the field.
In 1996 Steels founded the Sony Computer Science Laboratory (CSL) in Paris and became its acting director. This laboratory was a spin-off from the Sony Computer Science Laboratory in Tokyo directed by Mario Tokoro and Toshi Doi. The laboratory targeted cutting-edge research in AI, particularly on the emergence and evolution of grounded language and ontologies on robots, the use of AI in music, and contributions to sustainability. The CSL music group was directed by Francois Pachet and the sustainability group by Peter Hanappe.
In 2011 Steels became fellow at the Institute for Research and Advanced Studies (ICREA) and research professor at the Universitat Pompeu Fabra (UPF) in Barcelona, embedded in the Evolutionary Biology Laboratory (IBE). There he pursued further his fundamental research in the origins and evolution of language through experiments with robotic agents.
Throughout his career Steels spent many research and educational visits to other institutions. He was a regular lecturer at the Theseus International Management Institute in Sophia Antipolis, developed courses for the Open University in the N |
https://en.wikipedia.org/wiki/Magneto-optical%20drive | A magneto-optical drive is a kind of optical disc drive capable of writing and rewriting data upon a magneto-optical disc. Both 130 mm (5.25 in) and 90 mm (3.5 in) form factors exist. In 1983, just a year after the introduction of the compact disc, Kees Schouhamer Immink and Joseph Braat presented the first experiments with erasable magneto-optical compact discs during the 73rd AES
Convention in Eindhoven. The technology was introduced commercially in 1985. Although optical, they normally appear as hard disk drives to an operating system and can be formatted with any file system. Magneto-optical drives were common in some countries, such as Japan, but have fallen into disuse.
Overview
Early drives are 130 mm and have the size of full-height 130 mm hard-drives (like in the IBM PC XT). 130 mm media looks similar to a CD-ROM enclosed in an old-style caddy, while 90 mm media is about the size of a regular 3-inch floppy disk, but twice the thickness. The cases provide dust resistance, and the drives themselves have slots constructed in such a way that they always appear to be closed. Original MO systems were WORM (write once, read many), and later systems were read/write.
The disc consists of a ferromagnetic material sealed beneath a plastic coating. The only physical contact is during recording when a magnetic head is brought into contact with the side of the disc opposite to the laser, similar to Floptical drives, but not the same. During reading, a laser projects a beam on the disk and, according to the magnetic state of the surface, the reflected light varies due to the magneto-optic Kerr effect. During recording, laser power is increased to heat the material to the Curie point in a single spot. This enables an electromagnet positioned on the opposite side of the disc to change the local magnetic polarization. The polarization is retained after the temperature drops.
Each write cycle requires both a pass to erase a region and another pass to write information. Both passes use the laser to heat the recording layer; the magnetic field is used to change the magnetic orientation of the recording layer. The electromagnet reverses polarity for writing, and the laser is pulsed to record spots of "1" over the erased region of "0". As a result of this two-pass process, it takes twice as long to write data as it does to read it.
In 1996, Direct Overwrite technology was introduced for 90 mm discs eliminating the initial erase pass when writing. This requires special media.
By default, magneto-optical drives verify information after writing it to the disc, and are able to immediately report any problems to the operating system. This means writing can actually take three times longer than reading, but it makes the media extremely reliable, unlike the CD-R or DVD-R media upon which data is written without any concurrent data integrity checking. Using a magneto-optical disc is much more like using a diskette drive than a CD-RW drive.
During a read cycle, |
https://en.wikipedia.org/wiki/Alt.sex | alt.sex is a Usenet newsgroup – a discussion group within the Usenet network – relating to human sexual activity. It was popular in the 1990s. An October 1993 survey by Brian Reid reported an estimated worldwide readership for the newsgroup of 3.3 million, that being 8% of the total Usenet readership, with 67% of all Usenet "nodes" (news servers users log in to access the system) carrying the group. At that time, had an estimated traffic of 2,300 messages per month.
The newsgroup hierarchy below comprises several newsgroups, including (which is the biggest newsgroup in the hierarchy after itself), , , , , and . The former four newsgroups generally feature text and images similar to the type that can be found in mainstream adult magazines, such as Playboy or Penthouse. The latter three newsgroups exemplify a set of sub-groups that deals in more "extreme" or less socially accepted topics. Other sub-groups include some with intentionally humorous names, such as , , and . There are more newsgroups on the less mainstream topics or sub-cultures, although as of 1998 they were generally far lower in traffic than those that deal in the more mainstream sexual behaviours. In a 1993 analysis of the hierarchy, Maureen Furniss concluded that "sexually oriented boards act as a kind of support group for people who post notices to them, especially individuals whose sexual orientations are very marginalized (those who practice sadomasochism or bestiality, for example)."
The first usenet BDSM newsgroup, alt.sex.bondage, was created in 1991. The term BDSM itself was first recorded on a post in alt.sex.bondage in 1991.
The University of Waterloo in 1994 ceased carrying , , , and upon the recommendation of its ethics committee, which had expressed concerns that the content of those newsgroups may have violated the Canadian Criminal Code.
is a Usenet newsgroup set up specifically to help combat newsgroup spam cross-posted to the entire alt.sex hierarchy. The newsgroup is a simple "spamtrap" – a trap used to collect samples of unsolicited messages that can then be acted on by an automated anti-spam system. According to its charter, any message posted to may be cancelled automatically.
The well-known mass-mailing macro computer virus called the "Melissa virus" was originally distributed via the newsgroup. It was hidden inside a list purporting to contain passwords to pornographic websites. The messages containing the virus were posted with message headers claiming that the post had been written using the America Online (AOL) account of Scott Steinmetz, whose username was "skyroket". Kizza reports that the headers on the post were probably forged by Melissa's author, David L. Smith.
References
Further reading
External links
alt.sex Newsgroup FAQs
alt.sex.bondage group on Google
Usenet alt.* hierarchy
Sexuality and computing |
https://en.wikipedia.org/wiki/WPA | WPA may refer to:
Computing
Wi-Fi Protected Access, a wireless encryption standard
Windows Product Activation, in Microsoft software licensing
Wireless Public Alerting (Alert Ready), emergency alerts over LTE in Canada
Windows Performance Analyzer
Organizations
Wisconsin Philosophical Association
World Pool-Billiard Association
World Psychiatric Association
Western Provident Association, United Kingdom
United States
Works Progress Administration or Work Projects Administration, a former American New Deal agency
Washington Project for the Arts
Western Psychological Association
Women's Prison Association
Other
WPA, a 2009 album by Works Progress Administration (band)
Win probability added, a baseball statistic
Water pinch analysis
Whistleblower Protection Act, a law protecting certain whistleblowers in the USA
Woomera Prohibited Area, a tract of land in South Australia covering more than 120,000 sq km of arid 'outback'
Waterfowl production area, land protected through easements or purchase to conserve habitat for waterfowl in the United States
An abbreviation for Western Pennsylvania |
https://en.wikipedia.org/wiki/Digitization | Digitization is the process of converting information into a digital (i.e. computer-readable) format. The result is the representation of an object, image, sound, document, or signal (usually an analog signal) obtained by generating a series of numbers that describe a discrete set of points or samples. The result is called digital representation or, more specifically, a digital image, for the object, and digital form, for the signal. In modern practice, the digitized data is in the form of binary numbers, which facilitates processing by digital computers and other operations, but digitizing simply means "the conversion of analog source material into a numerical format"; the decimal or any other number system can be used instead.
Digitization is of crucial importance to data processing, storage, and transmission, because it "allows information of all kinds in all formats to be carried with the same efficiency and also intermingled." Though analog data is typically more stable, digital data has the potential to be more easily shared and accessed and, in theory, can be propagated indefinitely without generation loss, provided it is migrated to new, stable formats as needed. This potential has led to institutional digitization projects designed to improve access and the rapid growth of the digital preservation field.
Sometimes digitization and digital preservation are mistaken for the same thing. They are different, but digitization is often a vital first step in digital preservation. Libraries, archives, museums, and other memory institutions digitize items to preserve fragile materials and create more access points for patrons. Doing this creates challenges for information professionals and solutions can be as varied as the institutions that implement them. Some analog materials, such as audio and video tapes, are nearing the end of their life cycle, and it is important to digitize them before equipment obsolescence and media deterioration makes the data irretrievable.
There are challenges and implications surrounding digitization including time, cost, cultural history concerns, and creating an equitable platform for historically marginalized voices. Many digitizing institutions develop their own solutions to these challenges.
Mass digitization projects have had mixed results over the years, but some institutions have had success even if not in the traditional Google Books model.
Technological changes can happen often and quickly, so digitization standards are difficult to keep updated. Professionals in the field can attend conferences and join organizations and working groups to keep their knowledge current and add to the conversation.
Process
The term digitization is often used when diverse forms of information, such as an object, text, sound, image, or voice, are converted into a single binary code. The core of the process is the compromise between the capturing device and the player device so that the rendered result represents the orig |
https://en.wikipedia.org/wiki/History%20of%20computing | The history of computing is longer than the history of computing hardware and modern computing technology and includes the history of methods intended for pen and paper or for chalk and slate, with or without the aid of tables.
Concrete devices
Digital computing is intimately tied to the representation of numbers. But long before abstractions like the number arose, there were mathematical concepts to serve the purposes of civilization. These concepts are implicit in concrete practices such as:
One-to-one correspondence, a rule to count how many items, e.g. on a tally stick, eventually abstracted into numbers.
Comparison to a standard, a method for assuming reproducibility in a measurement, for example, the number of coins.
The 3-4-5 right triangle was a device for assuring a right angle, using ropes with 12 evenly spaced knots, for example.
Numbers
Eventually, the concept of numbers became concrete and familiar enough for counting to arise, at times with sing-song mnemonics to teach sequences to others. All known human languages, except the Piraha language, have words for at least "one" and "two", and even some animals like the blackbird can distinguish a surprising number of items.
Advances in the numeral system and mathematical notation eventually led to the discovery of mathematical operations such as addition, subtraction, multiplication, division, squaring, square root, and so forth. Eventually the operations were formalized, and concepts about the operations became understood well enough to be stated formally, and even proven. See, for example, Euclid's algorithm for finding the greatest common divisor of two numbers.
By the High Middle Ages, the positional Hindu–Arabic numeral system had reached Europe, which allowed for systematic computation of numbers. During this period, the representation of a calculation on paper actually allowed calculation of mathematical expressions, and the tabulation of mathematical functions such as the square root and the common logarithm (for use in multiplication and division) and the trigonometric functions. By the time of Isaac Newton's research, paper or vellum was an important computing resource, and even in our present time, researchers like Enrico Fermi would cover random scraps of paper with calculation, to satisfy their curiosity about an equation. Even into the period of programmable calculators, Richard Feynman would unhesitatingly compute any steps which overflowed the memory of the calculators, by hand, just to learn the answer; by 1976 Feynman had purchased an HP-25 calculator with a 49 program-step capacity; if a differential equation required more than 49 steps to solve, he could just continue his computation by hand.
Early computation
Mathematical statements need not be abstract only; when a statement can be illustrated with actual numbers, the numbers can be communicated and a community can arise. This allows the repeatable, verifiable statements which are the hallmark of mathematics a |
https://en.wikipedia.org/wiki/Brook | A brook is a small river or natural stream of fresh water. It may also refer to:
Computing
Brook, a programming language for GPU programming based on C
Brook+, an explicit data-parallel C compiler
BrookGPU, a framework for GPGPU programming
People
Brook (surname)
People with the given name Brook, or nickname
Brook Benton (1931–1988), American singer and songwriter
Brook Hannah (1874–1961), Australian rules footballer and missionary
Brook Mahealani Lee (born 1971), former Miss USA and Miss Universe (1997) from Hawaii, U.S.
Brook Lopez, American basketball player
Brook Taylor (1685–1731), English mathematician of Taylor series fame
Brook, a persona of Mary J. Blige
Brook, a fictional character in the manga and anime One Piece
Places
Brook, Indiana, United States
Brook, Isle of Wight, England
Brook, Kent, England
Brook, Surrey, England
Brook, Guildford, a hamlet in the parish of Albury, Surrey, England
Brook Islands National Park, Australia
Brook House Immigration Removal Centre, a detention centre near Gatwick Airport, England
Other uses
Brook (One Piece), a fictional skeleton from the anime and manga One Piece
Brook Advisory Centres, a British contraceptive services organisation
See also
Brock (disambiguation)
Brock (surname)
Brooke (disambiguation)
Brooks (disambiguation)
Bruck (disambiguation)
The Brook (disambiguation) |
https://en.wikipedia.org/wiki/Product%20key | A product key, also known as a software key, serial key or activation key, is a specific software-based key for a computer program. It certifies that the copy of the program is original.
Product keys consist of a series of numbers and/or letters. This sequence is typically entered by the user during the installation of computer software, and is then passed to a verification function in the program. This function manipulates the key sequence according to a mathematical algorithm and attempts to match the results to a set of valid solutions.
Effectiveness
Standard key generation, where product keys are generated mathematically, is not completely effective in stopping copyright infringement of software, as these keys can be distributed. In addition, with improved communication from the rise of the Internet, more sophisticated attacks on keys such as cracks (removing the need for a key) and product key generators have become common.
Because of this, software publishers use additional product activation methods to verify that keys are both valid and uncompromised. One method assigns a product key based on a unique feature of the purchaser's computer hardware, which cannot be as easily duplicated since it depends on the user's hardware. Another method involves requiring one-time or periodical validation of the product key with an internet server (for games with an online component, this is done whenever the user signs in). The server can deactivate unmodified client software presenting invalid or compromised keys. Modified clients may bypass these checks, but the server can still deny those clients information or communication.
Examples
Windows 95 retail key
Windows 95 retail product keys take the form XXX-XXXXXXX. To determine whether the key is valid, Windows 95 performs the following checks:
The first 3 characters must not be equal to 333, 444, 555, 666, 777, 888 or 999.
The last 7 characters must all be numbers from 0-8.
The sum of the last 7 numbers must be divisible by 7 with no remainder.
The fourth character is unchecked.
If all checks pass, the product key is valid.
Controversy
Some of the most effective product key protections are controversial due to inconvenience, strict enforcement, harsh penalties and, in some cases, false positives. Some product keys use uncompromising digital procedures to enforce the license agreement.
Inconvenience
Product keys are somewhat inconvenient for end users. Not only do they need to be entered whenever a program is installed, but the user must also be sure not to lose them. Loss of a product key usually means the software is useless once uninstalled, unless, prior to uninstallation, a key recovery application is used (although not all programs support this).
Product keys also present new ways for distribution to go wrong. If a product is shipped with missing or invalid keys, then the product itself is useless. For example, all copies of Splinter Cell: Pandora Tomorrow originally shipped to Aus |
https://en.wikipedia.org/wiki/Open-source%20intelligence | Open-source intelligence (OSINT) is the collection and analysis of data gathered from open sources (covert sources and publicly available information (PAI)) to produce actionable intelligence. OSINT is primarily used in national security, law enforcement, and business intelligence functions and is of value to analysts who use non-sensitive intelligence in answering classified, unclassified, or proprietary intelligence requirements across the previous intelligence disciplines.
Categories
OSINT sources can be divided up into six different categories of information flow:
Media, print newspapers, magazines, radio, and television from across and between countries.
Internet, online publications, blogs, discussion groups, citizen media (i.e. – cell phone videos, and user created content), YouTube, and other social media websites (i.e. – Facebook, Twitter, Instagram, etc.). This source also outpaces a variety of other sources due to its timeliness and ease of access.
Public government data, public government reports, budgets, hearings, telephone directories, press conferences, websites, and speeches. Although this source comes from an official source they are publicly accessible and may be used openly and freely.
Professional and academic publications, information acquired from journals, conferences, symposia, academic papers, dissertations, and theses.
Commercial data, commercial imagery, financial and industrial assessments, and databases.
Grey literature, technical reports, preprints, patents, working papers, business documents, unpublished works, and newsletters.
OSINT is distinguished from research in that it applies the process of intelligence to create tailored knowledge supportive of a specific decision by a specific individual or group.
Definition
OSINT is defined in the United States of America by Public Law 109-163 as cited by both the U.S. Director of National Intelligence and the U.S. Department of Defense (DoD), as intelligence "produced from publicly available information that is collected, exploited, and disseminated in a timely manner to an appropriate audience for the purpose of addressing a specific intelligence requirement." As defined by NATO, OSINT is intelligence "derived from publicly available information, as well as other unclassified information that has limited public distribution or access."
According to political scientist Jeffrey T. Richelson, “open source acquisition involves procuring verbal, written, or electronically transmitted material that can be obtained legally. In addition to documents and videos available via the Internet or provided by a human source, others are obtained after U.S. or allied forces have taken control of a facility or site formerly operated by a foreign government or terrorist group.”
Former Assistant Director of Central Intelligence for Analysis Mark M. Lowenthal defines OSINT as “any and all information that can be derived from overt collection: all types of media, government reports an |
https://en.wikipedia.org/wiki/Triple%20fault | On the x86 computer architecture, a triple fault is a special kind of exception generated by the CPU when an exception occurs while the CPU is trying to invoke the double fault exception handler, which itself handles exceptions occurring while trying to invoke a regular exception handler.
x86 processors beginning with the 80286 will cause a shutdown cycle to occur when a triple fault is encountered. This typically causes the motherboard hardware to initiate a CPU reset, which, in turn, causes the whole computer to reboot.
Possible causes of triple faults
Triple faults indicate a problem with the operating system kernel or device drivers. In modern operating systems, a triple fault is typically caused by a buffer overflow or underflow in a device driver which writes over the interrupt descriptor table (IDT). If the IDT is corrupted, when the next interrupt happens, the processor will be unable to call either the needed interrupt handler or the double fault handler because the descriptors in the IDT are corrupted.
Virtual machines
In QEMU, a triple fault produces a dump of the virtual machine in the console, with the instruction pointer set to the instruction that triggered the first exception.
In VirtualBox, a triple fault causes a Guru Meditation error to be displayed to the user. A virtual machine in this state has most features disabled and cannot be restarted. If the VirtualBox Debugger is open, a message is printed indicating a Triple fault has occurred, followed by a register dump and disassembly of the last instruction executed, similar to the output of the rg debugger command.
When using Intel VT-x, a triple fault causes a VM exit, with exit reason 2. The exit reason is saved to the VMCS and may be handled by the VMM software.
Other uses
The Intel 80286 processor was the first x86 processor to introduce the now-ubiquitous protected mode. However, the 286 could not revert to the basic 8086-compatible "real mode" without resetting the processor, which can only be done using hardware external to the CPU. On the IBM AT and compatibles, the documented method of doing this was to use a special function on the Intel 8042 keyboard controller, which would assert the RESET pin of the processor. However, intentionally triple-faulting the CPU was found to cause the transition to occur much faster (800 microseconds instead of 15+ milliseconds) and more cleanly, permitting multitasking operating systems to switch back and forth at high speed.
Some operating system kernels, such as Linux, still use triple faults as a last effort in their rebooting process if an ACPI reboot fails. This is done by setting the IDT register to 0 and then issuing an interrupt. Since the table now has length 0, all attempts to access it fail and the processor generates a triple fault.
References
Computer errors |
https://en.wikipedia.org/wiki/Alternative%20DNS%20root | The Internet uses the Domain Name System (DNS) to associate numeric computer IP addresses with human-readable names. The top level of the domain name hierarchy, the DNS root, contains the top-level domains that appear as the suffixes of all Internet domain names. The most widely used (and first) DNS root is administered by the Internet Corporation for Assigned Names and Numbers (ICANN). In addition, several organizations operate alternative DNS roots, often referred to as alt roots. These alternative domain name systems operate their own root name servers and commonly administer their own specific name spaces consisting of custom top-level domains.
The Internet Architecture Board (IAB) has spoken out strongly against alternative roots in .
Overview
The DNS root zone consists of pointers to the authoritative domain name servers for all top-level domains (TLDs). The root zone is hosted on a collection of root servers operated by several organizations around the world that all use a specific, approved list of domains that is managed by ICANN. By contrast, alternative roots typically include pointers to all of the TLD servers for domains delegated by ICANN, as well as name servers for other, custom top-level domains that are not sanctioned by ICANN. Some alternative roots are operated by the organizations that manage these alternative TLDs.
Zach Bastick proposes that alternative DNS roots have allowed for more democratic control of the Internet:
Unless one specifically changes their DNS resolution settings, alternative DNS top level domains are generally unreachable, and very few Internet service providers provide this configuration by default.
Implementations
Some organizations provide alternative DNS root services, such as additional top-level domains.
Handshake
Handshake is a decentralized implementation of a DNS root zone using blockchain and cryptocurrency technology to create a peer-to-peer alternative to the 13 root name servers managed by ICANN.
Unlike other attempts, Handshake does not aim to replace the existing DNS; rather, it seeks to supplement and enhance it by allowing anyone to bid, register, and manage their own TLDs without an intermediate registrar or delegating authority. Since the root zone file records are not centrally managed, and instead are stored on a public blockchain, owners of Handshake TLDs can add or change top-level resource records to delegate authoritative name servers and set up DNSSEC zone signing directly.
Existing TLDs are reserved in the Handshake blockchain such that resolving traditional domain names (i.e. zones under .com, .org, .net, etc.) through a Handshake node or name server are directed back to ICANN's root servers. In addition, the top 100,000 most popular domains are reserved as Handshake TLDs which can be redeemed by the original domain owner.
Namecoin
Namecoin is a blockchain and cryptocurrency to support the alternative top-level domain .bit.
OpenNIC
OpenNIC is a user owned and contro |
https://en.wikipedia.org/wiki/Computational%20learning%20theory | In computer science, computational learning theory (or just learning theory) is a subfield of artificial intelligence devoted to studying the design and analysis of machine learning algorithms.
Overview
Theoretical results in machine learning mainly deal with a type of inductive learning called supervised learning. In supervised learning, an algorithm is given samples that are labeled in some useful way. For example, the samples might be descriptions of mushrooms, and the labels could be whether or not the mushrooms are edible. The algorithm takes these previously labeled samples and uses them to induce a classifier. This classifier is a function that assigns labels to samples, including samples that have not been seen previously by the algorithm. The goal of the supervised learning algorithm is to optimize some measure of performance such as minimizing the number of mistakes made on new samples.
In addition to performance bounds, computational learning theory studies the time complexity and feasibility of learning. In
computational learning theory, a computation is considered feasible if it can be done in polynomial time. There are two kinds of time
complexity results:
Positive resultsShowing that a certain class of functions is learnable in polynomial time.
Negative resultsShowing that certain classes cannot be learned in polynomial time.
Negative results often rely on commonly believed, but yet unproven assumptions, such as:
Computational complexity – P ≠ NP (the P versus NP problem);
Cryptographic – One-way functions exist.
There are several different approaches to computational learning theory based on making different assumptions about the inference principles used to generalise from limited data. This includes different definitions of probability (see frequency probability, Bayesian probability) and different assumptions on the generation of samples. The different approaches include:
Exact learning, proposed by Dana Angluin;
Probably approximately correct learning (PAC learning), proposed by Leslie Valiant;
VC theory, proposed by Vladimir Vapnik and Alexey Chervonenkis;
Inductive inference as developed by Ray Solomonoff;
Algorithmic learning theory, from the work of E. Mark Gold;
Online machine learning, from the work of Nick Littlestone.
While its primary goal is to understand learning abstractly, computational learning theory has led to the development of practical algorithms. For example, PAC theory inspired boosting, VC theory led to support vector machines, and Bayesian inference led to belief networks.
See also
Error tolerance (PAC learning)
Grammar induction
Information theory
Occam learning
Stability (learning theory)
References
Further reading
A description of some of these publications is given at important publications in machine learning.
Surveys
Angluin, D. 1992. Computational learning theory: Survey and selected bibliography. In Proceedings of the Twenty-Fourth Annual ACM Symposium on Theory o |
https://en.wikipedia.org/wiki/Anycast | Anycast is a network addressing and routing methodology in which a single IP address is shared by devices (generally servers) in multiple locations. Routers direct packets addressed to this destination to the location nearest the sender, using their normal decision-making algorithms, typically the lowest number of BGP network hops. Anycast routing is widely used by content delivery networks such as web and name servers, to bring their content closer to end users.
Addressing methods
There are four principal addressing methods in the Internet Protocol:
History
The first documented use of anycast routing for topological load-balancing of Internet-connected services was in 1989, the technique was first formally documented in the IETF four years later. It was first applied to critical infrastructure in 2001 with the anycasting of the I-root nameserver.
Early objections
Early objections to the deployment of anycast routing centered on the perceived conflict between long-lived TCP connections and the volatility of the Internet's routed topology. In concept, a long-lived connection, such as an FTP file transfer (which can take hours to complete for large files) might be re-routed to a different anycast instance in mid-connection due to changes in network topology or routing, with the result that the server changes mid-connection, and the new server is not aware of the connection and does not possess the TCP connection state of the previous anycast instance.
In practice, such problems were not observed, and these objections dissipated by the early 2000s. Many initial anycast deployments consisted of DNS servers, using principally UDP transport. Measurements of long-term anycast flows revealed very few failures due to mid-connection instance switches, far fewer (less than 0.017% or "less than one flow per ten thousand per hour of duration" according to various sources) than were attributed to other causes of failure. Numerous mechanisms were developed to efficiently share state between anycast instances. And some TCP-based protocols, notably HTTP, incorporated "redirect" mechanisms, whereby anycast service addresses could be used to locate the nearest instance of a service, whereupon a user would be redirected to that specific instance prior to the initiation of any long-lived stateful transaction.
Internet Protocol version 4
Anycast can be implemented via Border Gateway Protocol (BGP). Multiple hosts (usually in different geographic areas) are given the same unicast IP address and different routes to the address are announced through BGP. Routers consider these to be alternative routes to the same destination, even though they are actually routes to different destinations with the same address. As usual, routers select a route by whatever distance metric is in use (the least cost, least congested, shortest). Selecting a route in this setup amounts to selecting a destination.
Internet Protocol version 6
Anycast is supported explicitly in the IPv6 |
https://en.wikipedia.org/wiki/RTD | RTD may refer to:
Science and technology
Real-time data
Residence time distribution
Resonant-tunneling diode
Round-trip delay time, in telecommunications
Research and development, Research and Technical (or Technological) Development
Resistance Temperature Detector, a resistance thermometer; RTD is also used to rate or describe plywood manufacturing processes where RTD sensors significantly reduce the delamination caused by insufficient heating of the plywood during the press cycle.
Broadcasting
Radio Tanzania Dar es Salaam
Radio Television of Djibouti (Radiodiffusion Télévision de Djibouti)
RT Documentary, an English- and Russian-language TV channel
Russell T Davies, Welsh screenwriter and television producer
Publications
RTD info, a European science magazine
Richmond Times-Dispatch newspaper, Virginia, US
Transportation
Regional Transportation District, Denver, Colorado, US
San Joaquin Regional Transit District, Stockton, California, US
Southern California Rapid Transit District, merged into Los Angeles County Metropolitan Transportation Authority
Other uses
Ready to drink beverage
Corner retirement (referee technical decision), in boxing
Retired (abbreviation)
Right to Die
Russell's theory of descriptions |
https://en.wikipedia.org/wiki/Southern%20Pacific%20Transportation%20Company | The Southern Pacific (or Espee from the railroad initials) was an American Class I railroad network that existed from 1865 to 1996 and operated largely in the Western United States. The system was operated by various companies under the names Southern Pacific Railroad, Southern Pacific Company and Southern Pacific Transportation Company.
The original Southern Pacific began in 1865 as a land holding company. The last incarnation of the Southern Pacific, the Southern Pacific Transportation Company, was founded in 1969 and assumed control of the Southern Pacific system. The Southern Pacific Transportation Company was acquired in 1996 by the Union Pacific Corporation and merged with their Union Pacific Railroad.
The Southern Pacific legacy founded hospitals in San Francisco, Tucson, and Houston. In the 1970s, it also founded a telecommunications network with a state-of-the-art microwave and fiber optic backbone. This telecommunications network became part of Sprint, a company whose name came from the acronym for Southern Pacific Railroad Internal Networking Telephony.
History
The original Southern Pacific, Southern Pacific Railroad, was founded as a land holding company in 1865, later acquiring the Central Pacific Railroad in 1885 through leasing. By 1900, the Southern Pacific system was a major railroad system incorporating many smaller companies, such as the Texas and New Orleans Railroad and Morgan's Louisiana and Texas Railroad. It extended from New Orleans through Texas to El Paso, across New Mexico and through Tucson, to Los Angeles, through most of California, including San Francisco and Sacramento. Central Pacific lines extended east across Nevada to Ogden, Utah, and reached north through Oregon to Portland. Other subsidiaries eventually included the St. Louis Southwestern Railway (Cotton Belt), El Paso and Southwestern Railroad,
the Northwestern Pacific Railroad at , the Southern Pacific Railroad of Mexico, and a variety of narrow-gauge routes. The SP was the defendant in the landmark 1886 United States Supreme Court case Santa Clara County v. Southern Pacific Railroad, which is often interpreted as having established certain corporate rights under the Constitution of the United States. The Southern Pacific Railroad was replaced by the Southern Pacific Company and assumed the railroad operations of the Southern Pacific Railroad. In 1929, Southern Pacific/Texas and New Orleans operated 13,848 route-miles not including Cotton Belt, whose purchase of the Golden State Route circa 1980 nearly doubled its size to , bringing total SP/SSW mileage to around .
In 1969, the Southern Pacific Transportation Company was established and took over the Southern Pacific Company; this Southern Pacific railroad is the last incarnation and was at times called "Southern Pacific Industries", though "Southern Pacific Industries" is not the official name of the company. By the 1980s, route mileage had dropped to , mainly due to the pruning of branch lines. O |
https://en.wikipedia.org/wiki/2001%20bomb%20plot%20in%20Europe | In 2001, a network of interconnected terrorist cells in France, Belgium, and the Netherlands was uncovered by law enforcement. The network had connections to al-Qaeda and was planning to commit one or more bombings.
Plot
Three cells were involved: one in Rotterdam, one in Brussels, and one in a suburb of Paris. According to Djamel Beghal, Nizar Trabelsi planned to strap a bomb onto himself, cover it up with a business suit, and then detonate the bomb along with himself in the U.S. Embassy in Paris. Concurrently, a van packed with explosives would be detonated outside a U.S. cultural centre at the nearby Place de la Madeleine. Trabelsi denied this, but admitted that he had planned to commit a suicide bombing by detonating a car bomb next to the canteen at Kleine Brogel Air Base in Belgium. Trabelsi also said that he had met Osama bin Laden and personally requested to become a suicide bomber.
Investigation
Beghal was arrested on 28 July 2001 in Dubai as he was attempting to travel back to Europe on a false French passport after visiting an al-Qaeda camp in Afghanistan. During interrogation, Beghal said that there was a plan to attack the U.S. Embassy in Paris and told investigators of terrorist cells in Rotterdam and Paris. He also said that Abu Zubaydah, a close associate of Osama bin Laden, had ordered the attack. After being extradited from the United Arab Emirates to France on 1 October 2001, Beghal retracted his confession, saying that it had been extracted using torture.
Surveillance of a suspected terrorist cell led by Kamel Daoudi in Corbeil-Essonnes near Paris started on 10 September. Following surveillance officers overhearing discussion of destroying evidence, French police moved in and arrested seven men on 21 September. Daoudi was not among the arrested, but he was shortly thereafter arrested in Leicester and extradited from the United Kingdom to France on 29 September 2001.
Dutch police started surveilling the Rotterdam cell in August. The four members of the cell were arrested on 13 September.
Police became aware of a connection between the Rotterdam cell and one led by Trabelsi in Brussels. Trabelsi and a Belgian Moroccan were arrested in two different areas of the Brussels metropolitan area on 13 September in an operation coordinated with the arrests in the Netherlands on the same day. At Trabelsi's apartment, police found machine pistols, chemical formulas for bomb-making, detailed maps of the U.S. embassy in Paris, and a business suit. In a restaurant run by one of Trabelsi's associates, police found materials that could have been used to make a bomb capable of blowing up a building.
Legal proceedings
In December 2002, four men were found not guilty of charges relating to the plot by a Dutch court, citing insufficient and improperly obtained evidence. Two of them, Jérôme Courtailler and Abdelghani Rabia, were convicted in absentia of belonging to a terrorist organization by an appellate court on 21 June 2004, and Courtail |
https://en.wikipedia.org/wiki/George%20Woltman | George Woltman (born November 10, 1957) is the founder of the Great Internet Mersenne Prime Search (GIMPS), a distributed computing project researching Mersenne prime numbers using his software Prime95. He graduated from the Massachusetts Institute of Technology (MIT) with a degree in computer science. He lives in North Carolina. His mathematical libraries created for the GIMPS project are the fastest known for multiplication of large integers, and are used by other distributed computing projects as well, such as Seventeen or Bust.
He also worked on a TTL version of Maze War while a student at MIT. Later he worked as a programmer for Data General.
See also
Prime95
References
External links
The Prime Pages Titan Biography
GIMPS home page
1957 births
Living people
Great Internet Mersenne Prime Search
20th-century American mathematicians
21st-century American mathematicians
MIT School of Engineering alumni |
https://en.wikipedia.org/wiki/Warren%20Robinett | Joseph Warren Robinett Jr. (born December 25, 1951) is a designer of interactive computer graphics software, notable as the developer of the Atari 2600's Adventure — the first graphical adventure video game — and as a founder of The Learning Company, where he designed Rocky's Boots and Robot Odyssey. More recently he has worked on virtual reality projects.
Robinett graduated in 1974 with a B.A. from Rice University, with a major in "Computer Applications to Language and Art". After graduating from Rice University, he was a Fortran programmer for Western Geophysical in Houston, Texas. He received an M.S. from University of California, Berkeley in 1976, and went to work at Atari, Inc. in November 1977.
Atari, Inc.
His first effort at Atari was Slot Racers for the Atari 2600. While he was working on it, he had discovered and played Crowther and Woods' Colossal Cave Adventure at the Stanford Artificial Intelligence Laboratory, and decided that a graphical video game version "would be really cool". However, with 128 bytes of RAM and 4096 bytes of ROM, Atari's Adventure was a much simpler program, and with only a joystick for input, the set of "commands" was necessarily brief. Adventure was a hit upon its 1979 release, and it eventually sold a million copies.
Atari designers at the time were not given credit for their games, because Atari feared having to bargain with well-known designers. In response to this, Robinett placed a hidden object in the game that would allow the player to reach a hidden screen which displayed the words "Created by Warren Robinett," hence creating one of the earliest known Easter eggs in a video game, and the first to which the name "Easter egg" was applied.
Robinett then wrote the BASIC Programming cartridge, finishing both BASIC Programming and Adventure in June 1979, and quit Atari.
The Learning Company and later
He founded The Learning Company in 1980, and he worked on several educational games there, including Rocky's Boots and Robot Odyssey for the Apple II. The Learning Company was acquired by Softkey in 1995 for US$606 million.
He has since worked on virtual reality projects for NASA and the University of North Carolina.
In 2016, Robinett announced The Annotated Adventure, a book describing the design and implementation of Adventure for the Atari 2600. In 2018 Robinett stated that the initial book was being split into two books: The Annotated Adventure focusing on the technical aspect of the game and Making the Dragon focusing on the political story. As of December 2022 only the table of contents has been made public.
Robinett's Adventure Easter egg is a plot element in the 2011 novel and 2018 film Ready Player One.
References
Further reading
External links
Warren Robinett's homepage
Warren Robinett at MobyGames
Warren Robinett on the history of Adventure, speaking at the Classic Gaming Expo 2002
1951 births
Living people
American video game programmers
Atari people
Rice University alumni
Universit |
https://en.wikipedia.org/wiki/Quantitative%20research | Quantitative research is a research strategy that focuses on quantifying the collection and analysis of data. It is formed from a deductive approach where emphasis is placed on the testing of theory, shaped by empiricist and positivist philosophies.
Associated with the natural, applied, formal, and social sciences this research strategy promotes the objective empirical investigation of observable phenomena to test and understand relationships. This is done through a range of quantifying methods and techniques, reflecting on its broad utilization as a research strategy across differing academic disciplines.
There are several situations where quantitative research may not be the most appropriate or effective method to use:
1. When exploring in-depth or complex topics.
2. When studying subjective experiences and personal opinions.
3. When conducting exploratory research.
4. When studying sensitive or controversial topics
The objective of quantitative research is to develop and employ mathematical models, theories, and hypotheses pertaining to phenomena. The process of measurement is central to quantitative research because it provides the fundamental connection between empirical observation and mathematical expression of quantitative relationships.
Quantitative data is any data that is in numerical form such as statistics, percentages, etc. The researcher analyses the data with the help of statistics and hopes the numbers will yield an unbiased result that can be generalized to some larger population. Qualitative research, on the other hand, inquires deeply into specific experiences, with the intention of describing and exploring meaning through text, narrative, or visual-based data, by developing themes exclusive to that set of participants.
Quantitative research is widely used in psychology, economics, demography, sociology, marketing, community health, health & human development, gender studies, and political science; and less frequently in anthropology and history. Research in mathematical sciences, such as physics, is also "quantitative" by definition, though this use of the term differs in context. In the social sciences, the term relates to empirical methods originating in both philosophical positivism and the history of statistics, in contrast with qualitative research methods.
Qualitative research produces information only on the particular cases studied, and any more general conclusions are only hypotheses. Quantitative methods can be used to verify which of such hypotheses are true. A comprehensive analysis of 1274 articles published in the top two American sociology journals between 1935 and 2005 found that roughly two-thirds of these articles used quantitative method.
Overview
Quantitative research is generally closely affiliated with ideas from 'the scientific method', which can include:
The generation of models, theories and hypotheses
The development of instruments and methods for measurement
Experimental control and m |
https://en.wikipedia.org/wiki/IWM | IWM may refer to:
Imperial War Museum, British national museum organisation
Information Warfare Monitor
iShares Russell 2000, NYSE Arca symbol
Integrated Woz Machine, Apple computer floppy drives
Intelligent workload management of computing resources
International Woman Master, now Woman International Master, chess titles
Institut für die Wissenschaften vom Menschen ("Institute for human sciences") (IWM) |
https://en.wikipedia.org/wiki/SPITBOL | SPITBOL (Speedy Implementation of SNOBOL) is a compiled implementation of the SNOBOL4 programming language. Originally targeted for the IBM System/360 and System/370 family of computers, it has now been ported to most major microprocessors including the SPARC. It was created by Robert Dewar and Ken Belcher, who were then at the Illinois Institute of Technology.
Prior to the development of SPITBOL, SNOBOL4 was thought to be slow, memory-intensive, and impossible to compile due to its dynamic nature. While delayed binding prevents everything from being determined at compile time, SPITBOL adopts various strategies for making decisions as early as possible. Recent versions of the SPITBOL compiler are available. Since 2001 the source code for the original SPITBOL 360 compiler has been made available under the GNU General Public License.
MACRO SPITBOL is an implementation of SPITBOL written in the 1970s by Robert Dewar and Anthony P. McCann. MACRO SPITBOL is coded in MINIMAL, an assembly language for an abstract machine. The instruction set is carefully defined to allow some latitude in its implementation, so that hardware operations favorable to string processing can be exploited.
An implementation of MINIMAL that was designed for interpretation on microcomputers was done by translating MINIMAL into MICRAL using a translator that was itself implemented in SPITBOL. The MICRAL version of MACRO SPITBOL, together with the MICRAL interpreter ran in under 40K bytes. This extreme object code compression of MICRAL is achieved using a set of machine code macro substitutions that minimizes the space required for the object code and macro table. The complexity of known algorithms for an optimal solution to this problem are high, but efficient heuristics attain near-optimal results.
The source code for MACRO SPITBOL was released under the GNU General Public License on April 17, 2009.
References
Compilers
Pattern matching programming languages
SNOBOL programming language family |
https://en.wikipedia.org/wiki/Search%20space | Search space may refer to one of the following:
In mathematical optimization and computer science, the set of all possible points of an optimization problem that satisfy the problem's targets or goals. It may also refer to the optimization of the domain of the function.
In artificial intelligence search algorithms, the feasible region defining the set of all possible solutions
In computational geometry, part of the input data in geometric search problems
Version space, developed via machine learning, is the subset of all hypotheses that are consistent with the observed training examples
See also
Space (disambiguation) |
https://en.wikipedia.org/wiki/Particle%20system | A particle system is a technique in game physics, motion graphics, and computer graphics that uses many minute sprites, 3D models, or other graphic objects to simulate certain kinds of "fuzzy" phenomena, which are otherwise very hard to reproduce with conventional rendering techniques – usually highly chaotic systems, natural phenomena, or processes caused by chemical reactions.
Introduced in the 1982 film Star Trek II: The Wrath of Khan for the fictional "Genesis effect", other examples include replicating the phenomena of fire, explosions, smoke, moving water (such as a waterfall), sparks, falling leaves, rock falls, clouds, fog, snow, dust, meteor tails, stars and galaxies, or abstract visual effects like glowing trails, magic spells, etc. – these use particles that fade out quickly and are then re-emitted from the effect's source. Another technique can be used for things that contain many strands – such as fur, hair, and grass – involving rendering an entire particle's lifetime at once, which can then be drawn and manipulated as a single strand of the material in question.
Particle systems are defined as a group of points in space, guided by a collection of rules defining behavior and appearance. Particle systems model phenomena as a cloud of particles, using stochastic processes to simplify the definition of dynamical system and fluid mechanics with that are difficult to represent with affine transformations.
Typical implementation
Particle systems typically implement the following modules:
An emission stage, which provides a location and generates new particles.
A simulation stage, which update parameters and simulates how particles evolve.
A rendering stage, which specifies how to render a particle.
Emission stage
An emitter implements a spawning rate (how many particles are generated per unit of time), the particles' initial velocity vector (the direction they are emitted upon creation). When using a mesh object as an emitter, the initial velocity vector is often set to be normal to the individual face(s) of the object, making the particles appear to "spray" directly from each face but this is optional.
Simulation stage
During the simulation stage, the number of new particles that must be created is calculated based on spawning rates and the interval between updates, and each of them is spawned in a specific position in 3D space based on the emitter's position and the spawning area specified. Each of the particle's parameters (i.e. velocity, color, etc.) is initialized according to the emitter's parameters. At each update, all existing particles are checked to see if they have exceeded their lifetime, in which case they are removed from the simulation. Otherwise, the particles' position and other characteristics are advanced based on a physical simulation, which can be as simple as translating their current position, or as complicated as performing physically accurate trajectory calculations which take into account external fo |
https://en.wikipedia.org/wiki/Zipf%E2%80%93Mandelbrot%20law | In probability theory and statistics, the Zipf–Mandelbrot law is a discrete probability distribution. Also known as the Pareto–Zipf law, it is a power-law distribution on ranked data, named after the linguist George Kingsley Zipf who suggested a simpler distribution called Zipf's law, and the mathematician Benoit Mandelbrot, who subsequently generalized it.
The probability mass function is given by:
where is given by:
which may be thought of as a generalization of a harmonic number. In the formula, is the rank of the data, and and are parameters of the distribution. In the limit as approaches infinity, this becomes the Hurwitz zeta function . For finite and the Zipf–Mandelbrot law becomes Zipf's law. For infinite and it becomes a Zeta distribution.
Applications
The distribution of words ranked by their frequency in a random text corpus is approximated by a power-law distribution, known as Zipf's law.
If one plots the frequency rank of words contained in a moderately sized corpus of text data versus the number of occurrences or actual frequencies, one obtains a power-law distribution, with exponent close to one (but see Powers, 1998 and Gelbukh & Sidorov, 2001). Zipf's law implicitly assumes a fixed vocabulary size, but the Harmonic series with s=1 does not converge, while the Zipf–Mandelbrot generalization with s>1 does. Furthermore, there is evidence that the closed class of functional words that define a language obeys a Zipf–Mandelbrot distribution with different parameters from the open classes of contentive words that vary by topic, field and register.
In ecological field studies, the relative abundance distribution (i.e. the graph of the number of species observed as a function of their abundance) is often found to conform to a Zipf–Mandelbrot law.
Within music, many metrics of measuring "pleasing" music conform to Zipf–Mandelbrot distributions.
Notes
References
Reprinted as
Van Droogenbroeck F.J., 'An essential rephrasing of the Zipf–Mandelbrot law to solve authorship attribution applications by Gaussian statistics' (2019)
External links
Z. K. Silagadze: Citations and the Zipf–Mandelbrot's law
NIST: Zipf's law
W. Li's References on Zipf's law
Gelbukh & Sidorov, 2001: Zipf and Heaps Laws’ Coefficients Depend on Language
C++ Library for generating random Zipf–Mandelbrot deviates.
Discrete distributions
Power laws
Computational linguistics
Quantitative linguistics
Corpus linguistics |
https://en.wikipedia.org/wiki/Larry%20Austin | Larry Don Austin (September 12, 1930 – December 30, 2018) was an American composer noted for his electronic and computer music works. He was a co-founder and editor of the avant-garde music periodical Source: Music of the Avant Garde. Austin gained additional international recognition when he realized a completion of Charles Ives's Universe Symphony. Austin served as the president of the International Computer Music Association (ICMA) from 1990 to 1994 and served on the board of directors of the ICMA from 1984 to 1988 and from 1990 to 1998.
Early life
Austin was born in Duncan, Oklahoma. He received a bachelor's (Music Education, 1951) and master's degree (Music, 1952) from University of North Texas College of Music. In 1955 he studied at Mills College, and from 1955 to 1958 he engaged in graduate study at the University of California, Berkeley, leaving to accept a faculty position at the University of California, Davis. Austin studied with Canadian composer Violet Archer at the University of North Texas, French composer Darius Milhaud at Mills College, and with American composer Andrew Imbrie at the University of California, Berkeley.
Teaching career
Austin taught at the University of California, Davis from 1958 till 1972 rising from assistant professor to full professor. While at the University of California, Davis, he founded the improvisational New Music Ensemble. In 1972 he accepted a position at the University of South Florida, where he taught until 1978. In that year he returned to Texas, teaching at his alma mater, the University of North Texas, from 1978 until 1996 when he was named professor emeritus. His notable students include William Basinski, Dary John Mizelle and Rodney Waschka II.
Compositions
Austin received early recognition for his instrumental and orchestral works and of those pieces, Improvisations for Orchestra and Jazz Soloists, was performed and recorded by the New York Philharmonic under Leonard Bernstein. Other orchestral works of special note include Charles Ives's Universe Symphony, "as realized and completed by Larry Austin" (1974–93) for large orchestra, and Sinfonia Concertante: A Mozartean Episode (1986) for chamber orchestra and tape. Chamber works with particularly significant computer music/electro-acoustic music aspects include Accidents for electronically prepared piano (1967), written for David Tudor, Canadian Coastlines: Canonic Fractals for Musicians and Computer Band for eight musicians and tape from 1981, and BluesAx for saxophonist and tape (1995), which won the Magisterium Prize, at Bourges in 1996. BluesAx has been recorded by Steve Duke.
Later work included John Explains... (2007) for octophonic sound, based on a recording of an interview with John Cage. John Explains... was premiered at the 2008 North Carolina Computer Music Festival. At the CEMI Circles festival, Austin's 2013 piece, Suoni della Bellagio—Sounds and sights of Bellagio, July–August, 1998 for video and two-channel tape was premi |
https://en.wikipedia.org/wiki/Keihin%E2%80%93T%C5%8Dhoku%20Line | The is a railway line in Japan which connects the cities of Saitama, Kawaguchi, Tokyo, Kawasaki, and Yokohama. It is part of the East Japan Railway Company (JR East) network. The line's name is derived from the characters for Tokyo (), Yokohama () and the Tōhoku Main Line (). The line runs parallel with the Tōkaidō Main Line between Yokohama and Tokyo and the Utsunomiya Line (part of the Tōhoku Main Line) except between Ueno and Akabane stations where the two lines are physically separate and thus alternate routes.
Most Keihin–Tōhoku Line trains have a through service onto the Negishi Line between Yokohama and Ōfuna stations. As a result, the entire service between Ōmiya and Ōfuna is typically referred to as the Keihin-Tōhoku–Negishi Line () on system maps and in-train station guides. Keihin-Tōhoku Line–Negishi Line trains are recognizable by their light blue stripe (the line's color on maps is also light blue).
Service outline
Trains run every 2–3 minutes at peak hours, every 5-6 minutes during the daytime, and less frequently the rest of the time. In general, these trains are classified as , stopping at all stations en route. However, all trains in the daytime (10:30-15:30) are classified as . These rapid trains skip some stations in central Tokyo, where the Keihin-Tōhoku Line runs parallel to the Yamanote Line.
Station list
Local trains stop at all stations. Rapid trains stop at stations marked "●" and "■". (Stations marked "■" allow cross-platform transfers to the Yamanote Line). Additionally, stations marked "▲" are served by rapid trains on weekends and national holidays only.
Keihin–Tōhoku Line
Rolling stock
As of January 2010, all Keihin-Tohoku Line services are formed of E233-1000 series 10-car electrical multiple unit (EMU) trains. These were phased in from December 2007, and replaced the previous 209 series 10-car EMUs by 24 January 2010. All Keihin-Tohoku Line rolling stock is based at Urawa Depot. Yokohama Line E233-6000 series 8-car EMUs also operate on through services over the Keihin-Tohoku Line between Higashi-Kanagawa and Ofuna stations.
Keihin–Tohoku Line & Negishi Line services
E233-1000 series 10-car EMUs (sky blue stripe) (from December 2007)
Yokohama Line through services
E233-6000 series 8-car EMUs (light/dark green stripe) (from February 2014)
Rolling stock used in the past
72 series 8-car EMUs (brown livery) (until October 1970)
101 series 10-car EMUs (sky blue livery) (from December 1970 until March 1978)
103 series 10-car EMUs (sky blue livery) (from October 1965 until March 1998)
205 series 10-car EMU (sky blue stripe) (from October 1989 until February 1996)
205 series 8-car EMUs (light/dark green stripe, on Yokohama Line through services until August 2014)
209-900 series 10-car EMUs (sky blue stripe) (from May 1992 until August 2007)
209-0 series 10-car EMUs (sky blue stripe) (from March 1993 until January 2010)
209-500 series 10-car EMUs (sky blue stripe) (from January 2001 until 2009)
Timeline
Hist |
https://en.wikipedia.org/wiki/Graphics%20processing%20unit | A graphics processing unit (GPU) is a specialized electronic circuit initially designed to accelerate computer graphics and image processing (either on a video card or embedded on motherboards, mobile phones, personal computers, workstations, and game consoles). After their initial design, GPUs were found to be useful for non-graphic calculations involving embarrassingly parallel problems due to their parallel structure. Other non-graphical uses include the training of neural networks and cryptocurrency mining.
History
1970s
Arcade system boards have used specialized graphics circuits since the 1970s. In early video game hardware, RAM for frame buffers was expensive, so video chips composited data together as the display was being scanned out on the monitor.
A specialized barrel shifter circuit helped the CPU animate the framebuffer graphics for various 1970s arcade video games from Midway and Taito, such as Gun Fight (1975), Sea Wolf (1976), and Space Invaders (1978). The Namco Galaxian arcade system in 1979 used specialized graphics hardware that supported RGB color, multi-colored sprites, and tilemap backgrounds. The Galaxian hardware was widely used during the golden age of arcade video games, by game companies such as Namco, Centuri, Gremlin, Irem, Konami, Midway, Nichibutsu, Sega, and Taito.
The Atari 2600 in 1977 used a video shifter called the Television Interface Adaptor. Atari 8-bit computers (1979) had ANTIC, a video processor which interpreted instructions describing a "display list"—the way the scan lines map to specific bitmapped or character modes and where the memory is stored (so there did not need to be a contiguous frame buffer). 6502 machine code subroutines could be triggered on scan lines by setting a bit on a display list instruction. ANTIC also supported smooth vertical and horizontal scrolling independent of the CPU.
1980s
The NEC µPD7220 was the first implementation of a personal computer graphics display processor as a single large-scale integration (LSI) integrated circuit chip. This enabled the design of low-cost, high-performance video graphics cards such as those from Number Nine Visual Technology. It became the best-known GPU until the mid-1980s. It was the first fully integrated VLSI (very large-scale integration) metal–oxide–semiconductor (NMOS) graphics display processor for PCs, supported up to 1024×1024 resolution, and laid the foundations for the emerging PC graphics market. It was used in a number of graphics cards and was licensed for clones such as the Intel 82720, the first of Intel's graphics processing units. The Williams Electronics arcade games Robotron 2084, Joust, Sinistar, and Bubbles, all released in 1982, contain custom blitter chips for operating on 16-color bitmaps.
In 1984, Hitachi released ARTC HD63484, the first major CMOS graphics processor for personal computers. The ARTC could display up to 4K resolution when in monochrome mode. It was used in a number of graphics cards and termi |
https://en.wikipedia.org/wiki/Ratfor | Ratfor (short for Rational Fortran) is a programming language implemented as a preprocessor for Fortran 66. It provides modern control structures, unavailable in Fortran 66, to replace GOTOs and statement numbers.
Features
Ratfor provides the following kinds of flow-control statements, described by Kernighan and Plauger as "shamelessly stolen from the language C, developed for the UNIX operating system by D.M. Ritchie" ("Software Tools", p. 318):
statement grouping with braces
if-else, while, for, do, repeat-until, break, next
"free-form" statements, i.e., not constrained by Fortran format rules
<, >, >=, ... in place of .LT., .GT., .GE., ...
include
# comments
For example, the following code
if (a > b) {
max = a
} else {
max = b
}
might be translated as
IF(.NOT.(A.GT.B))GOTO 1
MAX = A
GOTO 2
1 CONTINUE
MAX = B
2 CONTINUE
The version of Ratfor in Software Tools is written in Ratfor, as are the sample programs, and inasmuch as its own translation to Fortran is available, it can be ported to any Fortran system. Ratfor source code file names end in .r or .rat.
History
Ratfor was designed and implemented by Brian Kernighan at Bell Telephone Laboratories in 1974, and described in Software—Practice & Experience in 1975. It was used in the book "Software Tools" (Kernighan and Plauger, 1976).
In 1977, at Purdue University, an improved version of the Ratfor preprocessor was written. It was called Mouse4, as it was smaller and faster than Ratfor. A published document by Dr. Douglas Comer, professor at Purdue, concluded "contrary to the evidence exhibited by the designer of Ratfor, sequential search is often inadequate for production software. Furthermore, in the case of lexical analysis, well-known techniques do seem to offer efficiency while retaining the simplicity, ease of coding and modularity of ad hoc methods." (CSD-TR236).
In comparison to the Ratfor preprocessor on a program of 3000 source lines running on a CDC 6500 system took 185.470 CPU seconds. That was cut by 50% when binary search was used in the Ratfor code. Rewriting the ad hoc lexical scanner using a standard method based on finite automata reduced run time to 12.723 seconds.
With the availability of Fortran 77, a successor named Ratfiv (Ratfor=rat4 => rat5=Ratfiv) could, with an option /f77, output a more readable Fortran 77 code:
IF (A .GT. B) THEN
MAX = A
ELSE
MAX = B
ENDIF
Initial Ratfor source code was ported to C in 1985 and improved to produce Fortran 77 code too. A git tree has been set in 2010 in order to revive ratfor
.
Although the GNU C compiler had the ability to directly compile a Ratfor file (.r) without keeping a useless intermediate Fortran code (.f) (gcc foo.r), this functionality was lost in version 4 during the move in 2005 from f77 to GNU Fortran.
Source packages, .deb or src.rpm package are still available for users who need to compile old Ratfor software on any operating system. |
https://en.wikipedia.org/wiki/BLISS | BLISS is a system programming language developed at Carnegie Mellon University (CMU) by W. A. Wulf, D. B. Russell, and A. N. Habermann around 1970. It was perhaps the best known system language until C debuted a few years later. Since then, C became popular and common, and BLISS faded into obscurity. When C was in its infancy, a few projects within Bell Labs debated the merits of BLISS vs. C.
BLISS is a typeless block-structured programming language based on expressions rather than statements, and includes constructs for exception handling, coroutines, and macros. It does not include a goto statement.
The name is variously said to be short for Basic Language for Implementation of System Software or System Software Implementation Language, Backwards. However, in his 2015 oral history for the Babbage Institute's Computer Security History Project, Wulf claimed that the acronym was originally based on the name "Bill's Language for Implementing System Software."
The original Carnegie Mellon compiler was notable for its extensive use of optimizations, and formed the basis of the classic book The Design of an Optimizing Compiler.
Digital Equipment Corporation (DEC) developed and maintained BLISS compilers for the PDP-10, PDP-11, VAX, DEC PRISM, MIPS, DEC Alpha, and Intel IA-32, The language did not become popular among customers and few had the compiler, but DEC used it heavily in-house into the 1980s; most of the utility programs for the OpenVMS operating system were written in BLISS-32. The DEC BLISS compiler has been ported to the IA-64 and x86-64 architectures as part of the ports of OpenVMS to these platforms. The x86-64 BLISS compiler uses LLVM as its backend code generator, replacing the proprietary GEM backend used for Alpha and IA-64.
Language description
The BLISS language has the following characteristics:
All constants are full word for the machine being used, e.g. on a 16-bit machine such as the PDP-11, a constant is 16 bits; on a VAX computer, constants are 32 bits, and on a PDP-10, a constant is 36 bits.
A reference to a variable is always to the address of that variable. For example, the instruction Z+8 refers to adding 8 to the address of Z, not to its value. If one needs to add 8 to the value of Z, one must prefix the variable with a period; so one would type .Z+8 to perform this function, which adds 8 to the contents of Z.
Assignment is done with the standard = symbol, e.g. Z=8 – which says to create a full-word constant containing 8, and store it in the location whose address corresponds to that of Z. So Z+12=14 (or, alternatively 12+Z=14) places the constant 14 into the location which is 12 words after the address of Z. (This is considered bad practice.)
Block statements are similar to those of ALGOL: a block is started with a BEGIN statement and terminated with END. As with ALGOL, statements are terminated with the semicolon (";"). When a value is computed, it is saved until the next statement terminator – which means t |
https://en.wikipedia.org/wiki/Jython | Jython is an implementation of the Python programming language designed to run on the Java platform. The implementation was formerly known as JPython until 1999.
Overview
Jython programs can import and use any Java class. Except for some standard modules, Jython programs use Java classes instead of Python modules. Jython includes almost all of the modules in the standard Python programming language distribution, lacking only some of the modules implemented originally in C. For example, a user interface in Jython could be written with Swing, AWT or SWT. Jython compiles Python source code to Java bytecode (an intermediate language) either on demand or statically.
History
Jython was initially created in late 1997 to replace C with Java for performance-intensive code accessed by Python programs, moving to SourceForge in October 2000. The Python Software Foundation awarded a grant in January 2005. Jython 2.5 was released in June 2009.
Status and roadmap
The most recent release is Jython 2.7.3. It was released on September 10, 2022 and is compatible with Python 2.7.
Python 3 compatible changes are planned in Jython 3 Roadmap.
Although Jython implements the Python language specification, it has some differences and incompatibilities with CPython, which is the reference implementation of Python.
License terms
From version 2.2 on, Jython (including the standard library) is released under the Python Software Foundation License (v2). Older versions are covered by the Jython 2.0, 2.1 license and the JPython 1.1.x Software License.
The command-line interpreter is available under the Apache Software License.
Usage
JBoss Application Server's command line interface scripting using Jython
Oracle Weblogic Server Scripting Tool uses Jython
IBM Rational development tools allow Jython scripting
IBM WebSphere Application Server tool scripting with wsadmin allows using Jython and Jacl
ZK – a Java Ajax framework that allows glue logic written in Jython
Ignition - A software development platform focused on HMI and SCADA
Ghidra - a reverse engineering tool developed by the NSA allows plugins to be written in Java or Jython
openHAB - home automation software
See also
List of JVM languages
IronPython – an implementation of Python for .NET and Mono
PyPy – a self-hosting interpreter for the Python programming language.
JRuby – similar project for the Ruby programming language.
GraalVM - a polyglot runtime written in Java, has a Python 3 implementation
References
External links
JVM programming languages
Object-oriented programming languages
Python (programming language) implementations
Scripting languages
Software using the PSF license |
https://en.wikipedia.org/wiki/Tandy%202000 | The Tandy 2000 is a personal computer introduced by Radio Shack in September 1983 based on the 8 MHz Intel 80186 microprocessor running MS-DOS. By comparison, the IBM PC XT (introduced in March 1983) used the older 4.77 MHz Intel 8088 processor, and the IBM PC/AT (introduced in 1984) would later use the newer 6 MHz Intel 80286. Due to the 16-bit data bus and more efficient instruction decoding of the 80186, the Tandy 2000 ran significantly faster than other PC compatibles, and slightly faster than the PC AT. (Later IBM upgraded the 80286 in new PC AT models to 8 MHz, though with wait states.) The Tandy 2000 was the company's first computer built around an Intel x86 series microprocessor; previous models used the Zilog Z80 and Motorola 6809 CPUs.
While touted as being compatible with the IBM XT, the Tandy 2000 was different enough that most existing PC software that was not purely text-oriented failed to work properly.
The Tandy 2000 and its special version of MS-DOS supported up to 768 KB of RAM, significantly more than the 640 KB limit imposed by the IBM architecture. It used 80-track double-sided quad-density floppy drives of 720 KB capacity; the IBM standard at the time of the introduction of the Tandy 2000 was only 360 KB.
The Tandy 2000 had both "Tandy" and "TRS-80" logos on its case, marking the start of the phaseout of the "TRS-80" brand.
History
The introduction of IBM's Model 5150 Personal Computer in August 1981 created an entirely new market for microcomputers. Many hardware and software companies were founded specifically to exploit IBM's and Microsoft's new presence as a standard-setter for small computers, and most other established manufacturers shifted focus to it as well.
By this date Tandy/Radio Shack had been in the small-computer market for four years, since its August 1977 introduction of the TRS-80 Model I. The new computer division followed in October 1979 with the TRS-80 Model II—a high-end business-oriented system. In 1983 the TRS-80 Model 4 succeeded the Model III (which itself had replaced the Model I) in the consumer and educational markets. In the business segment the TRS-80 Model 12 and Model 16 succeeded the Model II, adding higher-end features. Thus far Tandy/Radio Shack's computer lines occupied their own niches in the market because of their proprietary system software and applications. Tandy attempted to monopolize software and peripheral sales by not offering third-party products in company stores. Until the IBM PC was introduced, the nearest thing to an industry standard in small computers was CP/M-80; no single manufacturer dominated.
By 1983 the IBM PC, and Tandy's discouraging of third-party products, had halved the company's market share and stopped profit growth. Tandy's motive for moving into the new MS-DOS domain was twofold: to capitalize on the new market, and to leverage sales opportunities afforded by their solid position in small computers. Marketing management believed that many Tandy custo |
https://en.wikipedia.org/wiki/List%20of%20computer%20term%20etymologies | This is a list of the origins of computer-related terms or terms used in the computing world (i.e., a list of computer term etymologies). It relates to both computer hardware and computer software.
Names of many computer terms, especially computer applications, often relate to the function they perform, e.g., a compiler is an application that compiles (programming language source code into the computer's machine language). However, there are other terms with less obvious origins, which are of etymological interest. This article lists such terms.
A
ABEND – originally from an IBM System/360 error message, short for "abnormal end". Jokingly reinterpreted as German Abend ("evening"), because "it is what system operators do to the machine late on Friday when they want to call it a day."
Ada – named after Ada Lovelace, who is considered by many to be the first programmer.
Apache – originally chosen from respect for the Native American Indian tribe of Apache. It was suggested that the name was appropriate, as Apache began as a series of patches to code written for NCSA's HTTPd daemon. The result was "a patchy" server.
AWK – composed of the initials of its authors Aho, Weinberger, and Kernighan.
B
B – probably a contraction of "BCPL", reflecting Ken Thompson's efforts to implement a smaller BCPL in 8 KB of memory on a DEC PDP-7. Or, named after Bon.
biff – named after a dog known by the developers at Berkeley, who – according to the UNIX manual page – died on 15 August 1993, at the age of 15, and belonged to a certain Heidi Stettner. Some sources report that the dog would bark at the mail carrier, making it a natural choice for the name of a mail notification system. The Jargon File contradicts this description, but confirms at least that the dog existed.
bit – first used by Claude E. Shannon in his seminal 1948 paper "A Mathematical Theory of Communication". Shannon's "bit" is a portmanteau of "binary digit". He attributed its origin to John W. Tukey, who had used the word in a Bell Labs memo of 9 January 1947.
Bon – created by Ken Thompson and named either after his wife Bonnie, or else after "a religion whose rituals involve the murmuring of magic formulas" (a reference to the Tibetan native religion Bön).
booting or bootstrapping – from the phrase "to pull oneself up by one's bootstraps", originally used as a metaphor for any self-initiating or self-sustaining process. Used in computing due to the apparent paradox that a computer must run code to load anything into memory, but code cannot be run until it is loaded.
bug – often (but erroneously) credited to Grace Hopper. In 1946, she joined the Harvard Faculty at the Computation Laboratory where she traced an error in the Harvard Mark II to a moth trapped in a relay. This bug was carefully removed and taped to the log book. However, use of the word 'bug' to describe defects in mechanical systems dates back to at least the 1870s, perhaps especially in Scotland. Thomas Edison, for on |
https://en.wikipedia.org/wiki/Overloading | The term overloading may refer to:
Function overloading, a software engineering process whereby multiple functions of different types are defined with the same name
Operator overloading, a software engineering process whereby operators (e.g. + or -) are treated as polymorphic functions having different behaviors depending on the types of arguments used
Overloading (chess), a tactical theme arising out of an opponent piece performing more than one defensive task in the game
Overloading, in weight training, refers to performing exercises with higher resistance than the muscles can handle, causing microtrauma which leads to hypertrophy or muscle growth
See also
Overload (disambiguation)
Overlay (disambiguation)
Overlap (disambiguation) |
https://en.wikipedia.org/wiki/Type%20introspection | In computing, type introspection is the ability of a program to examine the type or properties of an object
at runtime.
Some programming languages possess this capability.
Introspection should not be confused with reflection, which goes a step further and is the ability for a program to manipulate the values, metadata, properties, and functions of an object at runtime. Some programming languages also possess that capability (e.g.,
Java,
Python,
Julia,
and
Go).
Examples
Ruby
Type introspection is a core feature of Ruby. In Ruby, the Object class (ancestor of every class) provides and methods for checking the instance's class. The latter returns true when the particular instance the message was sent to is an instance of a descendant of the class in question. For example, consider the following example code (you can immediately try this with the Interactive Ruby Shell):
$ irb
irb(main):001:0> A=Class.new
=> A
irb(main):002:0> B=Class.new A
=> B
irb(main):003:0> a=A.new
=> #<A:0x2e44b78>
irb(main):004:0> b=B.new
=> #<B:0x2e431b0>
irb(main):005:0> a.instance_of? A
=> true
irb(main):006:0> b.instance_of? A
=> false
irb(main):007:0> b.kind_of? A
=> true
In the example above, the class is used as any other class in Ruby. Two classes are created, and , the former is being a superclass of the latter, then one instance of each class is checked. The last expression gives true because is a superclass of the class of .
Further, you can directly ask for the class of any object, and "compare" them (code below assumes having executed the code above):
irb(main):008:0> A.instance_of? Class
=> true
irb(main):009:0> a.class
=> A
irb(main):010:0> a.class.class
=> Class
irb(main):011:0> A > B
=> true
irb(main):012:0> B <= A
=> true
Objective-C
In Objective-C, for example, both the generic Object and NSObject (in Cocoa/OpenStep) provide the method which returns true if the argument to the method is an instance of the specified class. The method analogously returns true if the argument inherits from the specified class.
For example, say we have an and an class inheriting from .
Now, in the method we can write
- (void)eat:(id)sth {
if ([sth isKindOfClass:[Fruit class]]) {
// we're actually eating a Fruit, so continue
if ([sth isMemberOfClass:[Apple class]]) {
eatApple(sth);
} else if ([sth isMemberOfClass:[Orange class]]) {
eatOrange(sth);
} else {
error();
}
} else {
error();
}
}
Now, when is called with a generic object (an ), the function will behave correctly depending on the type of the generic object.
C++
C++ supports type introspection via the run-time type information (RTTI) typeid and dynamic_cast keywords.
The expression can be used to determine whether a particular object is of a particular derived class. For instance:
Person* p = dynamic_cast<Person *>(obj);
if (p != nullptr) {
p->walk();
}
The operator retrieves a object describing the mo |
https://en.wikipedia.org/wiki/Ad%20hoc%20polymorphism | In programming languages, ad hoc polymorphism is a kind of polymorphism in which polymorphic functions can be applied to arguments of different types, because a polymorphic function can denote a number of distinct and potentially heterogeneous implementations depending on the type of argument(s) to which it is applied. When applied to object-oriented or procedural concepts, it is also known as function overloading or operator overloading. The term ad hoc in this context is not intended to be pejorative; it refers simply to the fact that this type of polymorphism is not a fundamental feature of the type system. This is in contrast to parametric polymorphism, in which polymorphic functions are written without mention of any specific type, and can thus apply a single abstract implementation to any number of types in a transparent way. This classification was introduced by Christopher Strachey in 1967.
Early binding
Ad hoc polymorphism is a dispatch mechanism: control moving through one named function is dispatched to various other functions without having to specify the exact function being called. Overloading allows multiple functions taking different types to be defined with the same name; the compiler or interpreter automatically ensures that the right function is called. This way, functions appending lists of integers, lists of strings, lists of real numbers, and so on could be written, and all be called append—and the right append function would be called based on the type of lists being appended. This differs from parametric polymorphism, in which the function would need to be written generically, to work with any kind of list. Using overloading, it is possible to have a function perform two completely different things based on the type of input passed to it; this is not possible with parametric polymorphism. Another way to look at overloading is that a routine is uniquely identified not by its name, but by the combination of its name and the number, order and types of its parameters.
This type of polymorphism is common in object-oriented programming languages, many of which allow operators to be overloaded in a manner similar to functions (see operator overloading). Some languages that are not dynamically typed and lack ad hoc polymorphism (including type classes) have longer function names such as print_int, print_string, etc. This can be seen as advantage (more descriptive) or a disadvantage (overly verbose) depending on one's point of view.
An advantage that is sometimes gained from overloading is the appearance of specialization, e.g., a function with the same name can be implemented in multiple different ways, each optimized for the particular data types that it operates on. This can provide a convenient interface for code that needs to be specialized to multiple situations for performance reasons. The downside is that the type system cannot guarantee the consistency of the different implementations.
Since overloading is done at com |
https://en.wikipedia.org/wiki/GNU%20Classpath | GNU Classpath is a free software implementation of the standard class library for the Java programming language. Most classes from J2SE 1.4 and 5.0 are implemented. Classpath can thus be used to run Java-based applications. GNU Classpath is a part of the GNU Project. It was originally developed in parallel with libgcj due to license incompatibilities, but later the two projects merged.
GNU Classpath was deemed a high priority project by the Free Software Foundation. When the Classpath project began, the license for the official Java implementation from Sun Microsystems did not allow distribution of any alterations. Since the inception of the Classpath project, the OpenJDK was released under the GPL and now serves as the official reference implementation for the Java platform.
License
GNU Classpath is licensed under the GNU General Public License with a linking exception. This is a free software license. All code is formally owned by the Free Software Foundation, and this owner is bound by its own contractual obligations to the developers.
Uses
GNU Classpath is used by many free Java runtimes (like Kaffe, SableVM, JamVM, Jikes RVM, and VMKit) because every full-featured Java virtual machine must provide an implementation of the standard class libraries.
Some other uses include:
The GNU Compiler for Java, which is capable of compiling Java code into native standalone executables.
GCJAppletViewer for launching Java applets from command line if they are not supported by the browser in use.
IKVM.NET, which integrates Java with the .NET Framework
JNode, an operating system for running Java applications. This system is written in Java and assembler only.
Specialised virtual machines such as Jaos for integration with the Oberon programming language, and JamaicaVM for embedded systems with real-time guarantees.
Virtual machines for distributed computing with clusters, having up to 128 processors on Myrinet.
The IcedTea project used GNU Classpath as a replacement for proprietary elements of OpenJDK, prior to their replacement upstream.
History
GNU Classpath development started in 1998 with five developers. During the history, it merged several times with other projects having similar goals (Kaffe, libgcj). In the past, GNU Classpath supplied its own virtual machine (Japhar). As Classpath was becoming a base library, shared with a lot of different projects, this virtual machine received less and less attention and is now no longer supported.
After implementing the majority of the official Java 1.4 API, the work in the project became more bug oriented rather than API coverage oriented. On October 24, 2006, the implementation of the last missing 1.4 class, HTMLWriter, was committed. The development speed (computed mathematically as the average number of the new lines of code per day) reached its highest ever in 2006.
The name GNU Classpath was originally suggested by Bradley M. Kuhn to one of the first developers, Paul Fisher. At the tim |
https://en.wikipedia.org/wiki/Re-order%20buffer | A re-order buffer (ROB) is a hardware unit used in an extension to the Tomasulo algorithm to support out-of-order and speculative instruction execution. The extension forces instructions to be committed in-order.
The buffer is a circular buffer (to provide a FIFO instruction ordering queue) implemented as an array/vector (which allows recording of results against instructions as they complete out of order).
There are three stages to the Tomasulo algorithm: "Issue", "Execute", "Write Result". In an extension to the algorithm, there is an additional "Commit" stage. During the Commit stage, instruction results are stored in a register or memory. The "Write Result" stage is modified to place results in the re-order buffer. Each instruction is tagged in the reservation station with its index in the ROB for this purpose.
The contents of the buffer are used for data dependencies of other instructions scheduled in the buffer. The head of the buffer will be committed once its result is valid. Its dependencies will have already been calculated and committed since they must be ahead of the instruction in the buffer though not necessarily adjacent to it. Data dependencies between instructions would normally stall the pipeline while an instruction waits for its dependent values. The ROB allows the pipeline to continue to process other instructions while ensuring results are committed in order to prevent data hazards such as read ahead of write (RAW), write ahead of read (WAR) and write ahead of write (WAW).
There are additional fields in every entry of the buffer to support the extended algorithm:
Instruction type (jump, store to memory, store to register)
Destination (either memory address or register number)
Result (value that goes to destination or indication of a (un)successful jump)
Validity (does the result already exist?)
The consequences of the re-order buffer include precise exceptions and easy rollback control of target address mis-predictions (branch or jump). When jump prediction is not correct or a nonrecoverable exception is encountered in the instruction stream, the ROB is cleared of all instructions (by setting the circular queue tail to the head) and reservation stations are re-initialized.
References
External links
Hardware Based Speculation - Prof. Dr. Ben H. Juurlink
Reorder Buffer
Instruction processing |
https://en.wikipedia.org/wiki/PTL | PTL may refer to:
The PTL Club, a former television program
PTL Satellite Network
Pass transistor logic in digital electronic circuits
Pittsburgh Today Live, program on KDKA-TV
Propositional temporal logic (Linear temporal logic)
"PTL", a song by Relient K from the album Collapsible Lung
Paschall Truck Lines |
https://en.wikipedia.org/wiki/Tomasulo%27s%20algorithm | Tomasulo's algorithm is a computer architecture hardware algorithm for dynamic scheduling of instructions that allows out-of-order execution and enables more efficient use of multiple execution units. It was developed by Robert Tomasulo at IBM in 1967 and was first implemented in the IBM System/360 Model 91’s floating point unit.
The major innovations of Tomasulo’s algorithm include register renaming in hardware, reservation stations for all execution units, and a common data bus (CDB) on which computed values broadcast to all reservation stations that may need them. These developments allow for improved parallel execution of instructions that would otherwise stall under the use of scoreboarding or other earlier algorithms.
Robert Tomasulo received the Eckert–Mauchly Award in 1997 for his work on the algorithm.
Implementation concepts
The following are the concepts necessary to the implementation of Tomasulo's algorithm:
Common data bus
The Common Data Bus (CDB) connects reservation stations directly to functional units. According to Tomasulo it "preserves precedence while encouraging concurrency". This has two important effects:
Functional units can access the result of any operation without involving a floating-point-register, allowing multiple units waiting on a result to proceed without waiting to resolve contention for access to register file read ports.
Hazard Detection and control execution are distributed. The reservation stations control when an instruction can execute, rather than a single dedicated hazard unit.
Instruction order
Instructions are issued sequentially so that the effects of a sequence of instructions, such as exceptions raised by these instructions, occur in the same order as they would on an in-order processor, regardless of the fact that they are being executed out-of-order (i.e. non-sequentially).
Register renaming
Tomasulo's algorithm uses register renaming to correctly perform out-of-order execution. All general-purpose and reservation station registers hold either a real value or a placeholder value. If a real value is unavailable to a destination register during the issue stage, a placeholder value is initially used. The placeholder value is a tag indicating which reservation station will produce the real value. When the unit finishes and broadcasts the result on the CDB, the placeholder will be replaced with the real value.
Each functional unit has a single reservation station. Reservation stations hold information needed to execute a single instruction, including the operation and the operands. The functional unit begins processing when it is free and when all source operands needed for an instruction are real.
Exceptions
Practically speaking, there may be exceptions for which not enough status information about an exception is available, in which case the processor may raise a special exception, called an "imprecise" exception. Imprecise exceptions cannot occur in in-order implementations, as processor |
https://en.wikipedia.org/wiki/Hazard%20%28computer%20architecture%29 | In the domain of central processing unit (CPU) design, hazards are problems with the instruction pipeline in CPU microarchitectures when the next instruction cannot execute in the following clock cycle, and can potentially lead to incorrect computation results. Three common types of hazards are data hazards, structural hazards, and control hazards (branching hazards).
There are several methods used to deal with hazards, including pipeline stalls/pipeline bubbling, operand forwarding, and in the case of out-of-order execution, the scoreboarding method and the Tomasulo algorithm.
Background
Instructions in a pipelined processor are performed in several stages, so that at any given time several instructions are being processed in the various stages of the pipeline, such as fetch and execute. There are many different instruction pipeline microarchitectures, and instructions may be executed out-of-order. A hazard occurs when two or more of these simultaneous (possibly out of order) instructions conflict.
Types
Data hazards
Data hazards occur when instructions that exhibit data dependence modify data in different stages of a pipeline. Ignoring potential data hazards can result in race conditions (also termed race hazards). There are three situations in which a data hazard can occur:
read after write (RAW), a true dependency
write after read (WAR), an anti-dependency
write after write (WAW), an output dependency
Read after read (RAR) is not a hazard case.
Consider two instructions and , with occurring before in program order.
Read after write (RAW)
( tries to read a source before writes to it)
A read after write (RAW) data hazard refers to a situation where an instruction refers to a result that has not yet been calculated or retrieved. This can occur because even though an instruction is executed after a prior instruction, the prior instruction has been processed only partly through the pipeline.
Example
For example:
i1. R2 <- R5 + R3
i2. R4 <- R2 + R3
The first instruction is calculating a value to be saved in register , and the second is going to use this value to compute a result for register . However, in a pipeline, when operands are fetched for the 2nd operation, the results from the first have not yet been saved, and hence a data dependency occurs.
A data dependency occurs with instruction , as it is dependent on the completion of instruction .
Write after read (WAR)
( tries to write a destination before it is read by )
A write after read (WAR) data hazard represents a problem with concurrent execution.
Example
For example:
i1. R4 <- R1 + R5
i2. R5 <- R1 + R2
In any situation with a chance that may finish before (i.e., with concurrent execution), it must be ensured that the result of register is not stored before has had a chance to fetch the operands.
Write after write (WAW)
( tries to write an operand before it is written by )
A write after write (WAW) data hazard may occur in a concurrent execution environment |
https://en.wikipedia.org/wiki/NOP%20%28code%29 | In computer science, a NOP, no-op, or NOOP (pronounced "no op"; short for no operation) is a machine language instruction and its assembly language mnemonic, programming language statement, or computer protocol command that does nothing.
Machine language instructions
Some computer instruction sets include an instruction whose explicit purpose is to not change the state of any of the programmer-accessible registers, status flags, or memory. It often takes a well-defined number of clock cycles to execute. In other instruction sets, there is no explicit NOP instruction, but the assembly language mnemonic NOP represents an instruction which acts as a NOP; e.g., on the SPARC, sethi 0, %g0.
A NOP must not access memory, as that could cause a memory fault or page fault.
A NOP is most commonly used for timing purposes, to force memory alignment, to prevent hazards, to occupy a branch delay slot, to render void an existing instruction such as a jump, as a target of an execute instruction, or as a place-holder to be replaced by active instructions later on in program development (or to replace removed instructions when reorganizing would be problematic or time-consuming). In some cases, a NOP can have minor side effects; for example, on the Motorola 68000 series of processors, the NOP opcode causes a synchronization of the pipeline.
Listed below are the NOP instruction for some CPU architectures:
From a hardware design point of view, unmapped areas of a bus are often designed to return zeroes; since the NOP slide behavior is often desirable, it gives a bias to coding it with the all-zeroes opcode.
Code
A function or a sequence of programming language statements is a NOP or null statement if it has no effect. Null statements may be required by the syntax of some languages in certain contexts.
Ada
In Ada, the null statement serves as a NOP. As the syntax forbids that control statements or functions be empty, the null statement must be used to specify that no action is required. (Thus, if the programmer forgets to write a sequence of statements, the program will fail to compile.)
C and derivatives
The simplest NOP statement in C is the null statement, which is just a semi-colon in a context requiring a statement.
;
An empty block (compound statement) is also a NOP, and may be more legible:
{}
In some cases, such as the body of a function, a block must be used, but this can be empty. In C, statements cannot be empty—simple statements must end with a ; (semicolon) while compound statements are enclosed in {} (braces), which does not itself need a following semicolon. Thus in contexts where a statement is grammatically required, some such null statement can be used.
The null statement is useless by itself, but it can have a syntactic use in a wider context, e.g., within the context of a loop:
while (getchar() != '\n') {}
alternatively,
while (getchar() != '\n')
;
or more tersely:
while (getchar() != '\n');
(note that the last form |
https://en.wikipedia.org/wiki/Red%20Hat%20%28disambiguation%29 | Red Hat is an American software company that provides open source software products.
Red hat or Red Hat may also refer to:
Red Hat Enterprise Linux, a computer operating system
Red Hat Linux, a computer operating system
Red Hat, a site in Project 112, an American biological and chemical weapon experimentation project
Red Hat sect, three different schools of Tibetan Buddhism
Red Hat Society, a social organization traditionally for women over 50
Red hat, on of de Bono's Six Thinking Hats
Red hat, a trainee in a volunteer fire department
Red Hat Cell Block, a former prison cell block at the Louisiana State Penitentiary
Operation Red Hat, a 1971 United States movement of chemical warfare munitions
See also
Redcap (disambiguation)
Red beret, a military beret worn by many military police forces
Galero, a red hat traditionally worn by cardinals of the Catholic Church
Zucchetto, a small, hemispherical, form-fitting ecclesiastical skullcap
Make America Great Again |
https://en.wikipedia.org/wiki/Youth%20For%20Understanding | Youth For Understanding (YFU) is an international educational exchange organization. A network of over 50 independent national organizations worldwide, YFU representatives work together to advance learning across cultures.
Each year, YFU exchanges approximately 4,500 students worldwide.
Organization
YFU conducts its exchange programs via direct contact between independent national organizations in over 50 countries. These autonomous organizations represent the international community network of YFU. Other YFU international activities are carried out by a volunteer International Advisory Council and a professional staff known as the International Secretariat.
YFU organizations around the world subscribe to a set of basic operating and philosophic basic standards.
The umbrella body for national Youth For Understanding organisations across Europe is EEE-YFU.
History of YFU
Youth for Understanding was founded by Rachel Andresen. In 1951 it was proposed to church leaders in Ann Arbor, Michigan, USA that teenagers from Germany be brought to the United States to live with a family and attend high school for a year. As a result, 75 German teenagers arrived in Michigan in July 1951 and were hosted by volunteer U.S. families.
The exchange program itself originated in late summer 1951 by the High Commission in Germany as the "Urban/Rural Teen-Age Exchange Program". Already in its first year it was supported by members of the Michigan Council of Churches (MCC) under the motto "Youth for Understanding". Within the next 10 years it evolved into two organizations YFU-USA and YFU-Germany. The first "exchange" from the United States to Germany was a summer program with 30 US high school students organized by MCC-alumni. During that year, Germany became a sovereign country, and the US government stopped funding the exchange program with Germany, which continued as a not-for-profit activity between the two YFU organizations. In 1961/62, a one-year exchange program from the US to Germany was added with 6 initial students from the US.
YFU Japan and YFU Mexico were established in 1958.
YFU, Inc., the non-profit educational organization, was established in 1964, and the organization's offices were moved to Rosedale in Washington, D.C. in 1978.
On March 8, 2002, YFU, Inc. ceased operations and filed for Chapter 11 bankruptcy later that year.
The YFU organization in United States was reorganized as YFU USA Inc., which opened on March 9, 2002. The organization's offices were moved to Bethesda, Maryland later in 2002. Ulrich Zahlten, founder and former chair of YFU Deutschland, became the new chairman of the board of YFU USA.
Organization
The guidelines for the work of the national YFU organizations will be decided by the International Advisory Council. The committee, which meets twice a year, consists of 15 representatives from national organizations. The national organisations from the United States, Germany and Japan as the largest members are constantly repre |
https://en.wikipedia.org/wiki/IBM%20Information%20Management%20System | The IBM Information Management System (IMS) is a joint hierarchical database and information management system that supports transaction processing.
History
IBM designed the IMS with Rockwell and Caterpillar starting in 1966 for the Apollo program, where it was used to inventory the very large bill of materials (BOM) for the Saturn V Moon rocket and Apollo space vehicle.
The first "IMS READY" message appeared on an IBM 2740 terminal in Downey, California, on August 14, 1968.
In the interim period, IMS has undergone many developments as IBM System/360 technology evolved into the current z/OS and IBM zEnterprise System technologies. For example, IMS now supports the Java programming language, JDBC, XML, and, since late 2005, web services.
Vern Watts was IMS's chief architect for many years. Watts joined IBM in 1956 and worked at IBM's Silicon Valley development labs until his death on April 4, 2009. He had continuously worked on IMS since the 1960s.
Database
The IMS Database component stores data using a hierarchical model, which is quite different from IBM's later released relational database, IBM Db2. In IMS, the hierarchical model is implemented using blocks of data known as segments. Each segment can contain several pieces of data, which are called fields. For example, a customer database may have a root segment (or the segment at the top of the hierarchy) with fields such as phone, name, and age. Child segments may be added underneath another segment, for instance, one order segment under each customer segment represents each order a customer has placed with a company. Likewise, each order segment may have many children segments for each item on the order.
Unlike other databases, you do not need to define all of the data in a segment to IMS. A segment may be defined with a size of 40 bytes but only define one field that is six bytes long as a key field that you can use to find the segment when performing queries. IMS will retrieve and save all 40 bytes as directed by a program but may not understand (or care) what the other bytes represent. In practice, often all the data in a segment may map to a COBOL copybook. Besides DL/I query usage, a field may be defined in IMS so that the data can be hidden from certain applications for security reasons. The database component of IMS can be purchased standalone, without the transaction manager component, and used by systems such as CICS.
There are three basic forms of IMS hierarchical databases:
"Full Function" databases
Directly descended from the Data Language Interface (DL/I) databases originally developed for Apollo, full function databases can have primary and secondary indexes, accessed using DL/I calls from an application program, like SQL calls to IBM Db2 or Oracle.
Full function databases can be accessed by a variety of methods, although Hierarchical Direct (HDAM) and Hierarchical Indexed Direct (HIDAM) dominate. The other formats are Simple Hierarchical Indexed Sequential |
https://en.wikipedia.org/wiki/Parametric | Parametric may refer to:
Mathematics
Parametric equation, a representation of a curve through equations, as functions of a variable
Parametric statistics, a branch of statistics that assumes data has come from a type of probability distribution
Parametric derivative, a type of derivative in calculus
Parametric model, a family of distributions that can be described using a finite number of parameters
Parametric oscillator, a harmonic oscillator whose parameters oscillate in time
Parametric surface, a particular type of surface in the Euclidean space R3
Parametric family, a family of objects whose definitions depend on a set of parameters
Science
Parametric process, in optical physics, any process in which an interaction between light and matter does not change the state of the material
Spontaneous parametric down-conversion, in quantum optics, a source of entangled photon pairs and of single photons
Optical parametric amplifier, a type of laser light source that emits light of variable wavelengths
Statistical parametric mapping, a statistical technique for examining differences in brain activity recorded during functional neuroimaging
Parametric search
Financial services
Parametric contract, a financial or investment contract
Parametric insurance, insurance that agrees to make a payment upon the occurrence of a triggering event
Parametric feature based modeler, a modeler using features defined to be parametric shapes associated with attributes
Computing
Parametric polymorphism, a feature of some type systems in computer programming
Parametric animation, a computer-animation technique
Parametric Technology Corporation, an American technology company
Software parametric models, a set of related mathematical equations that incorporates variable parameters
Other uses
Parametric feature based modeler, a modeler using features defined to be parametric shapes associated with attributes
Parametric determinism, a Marxist interpretation of the course of history
Parametric equalizer, a multi-band variable equalizer
Parametric array, a nonlinear transduction mechanism
Parametric design, a design process
See also
Parameter (disambiguation) |
https://en.wikipedia.org/wiki/Job%20Control%20Language | Job Control Language (JCL) is a name for scripting languages used on IBM mainframe operating systems to instruct the system on how to run a batch job or start a subsystem. The purpose of JCL is to say which programs to run, using which files or devices for input or output, and at times to also indicate under what conditions to skip a step. Parameters in the JCL can also provide accounting information for tracking the resources used by a job as well as which machine the job should run on.
There are two distinct IBM Job Control languages:
one for the operating system lineage that begins with DOS/360 and whose latest member is z/VSE; and
the other for the lineage from OS/360 to z/OS, the latter now including JES extensions, Job Entry Control Language (JECL).
They share some basic syntax rules and a few basic concepts, but are otherwise very different.
The VM operating system does not have JCL as such; the CP and CMS components each have command languages.
Terminology
Certain words or phrases used in conjunction to JCL are specific to IBM mainframe technology.
Dataset: a "dataset" is a file; it can be temporary or permanent, and located on a disk drive, tape storage, or other device.
Member: a "member" of a partitioned dataset (PDS) is an individual dataset within a PDS. A member can be accessed by specifying the name of the PDS with the member name in parentheses. For example, the system macro GETMAIN in SYS1.MACLIB can be referenced as SYS1.MACLIB(GETMAIN).
Partitioned dataset: a "partitioned dataset" or PDS is collection of members, or archive. Partitioned datasets are commonly used to store textual data such as source code, assembler macros (SYS1.MACLIB), system configuration (SYS1.PARMLIB), reusable JCL procedures (SYS1.PROCLIB), etc. As such, they have something in common with archive files (ZIP, TAR, etc) and with directories in other operating systems. They are also used to store binary code (load modules or program objects); in that guise, they are roughly analogous to ar-based static libraries in Unix-based systems. As with most such structures, a member, once stored, cannot be updated; the member must be deleted and replaced, such as with the IEBUPDTE utility. Since the 1989 release of MVS DFP 3.2, PDSEs (Partitioned Data Set Extended) have existed as an improved version of PDS; from the user or application programmer viewpoint, they are largely unchanged (save the removal of some obscure legacy features), but their internal implementation is very different.
USS: Unix system services, a complete Unix environment running as part of the MVS base control program, and allowing Unix files, scripts, tasks, and programs to run on a mainframe in a fully POSIX compliant Unix environment without virtualization.
Motivation
Originally, mainframe systems were oriented toward batch processing. Many batch jobs require setup, with specific requirements for main storage, and dedicated devices such as magnetic tapes, private disk volumes, and |
https://en.wikipedia.org/wiki/Jean-Louis%20Gass%C3%A9e | Jean-Louis Gassée (born March 1944 in Paris, France) is a business executive. He is best known as a former executive at Apple Computer, where he worked from 1981 to 1990. He also founded Be Inc., creators of the BeOS computer operating system. After leaving Be, he became Chairman of PalmSource, Inc. in November 2004.
Career
1980s: Apple Computer
Gassée worked for six years at Hewlett-Packard from 1968 to 1974, where he was responsible for overseeing the launching of the company’s first desktop scientific computer and the development of its sales organization in France, before his promotion to Sales Manager of Europe, in Geneva, Switzerland. From 1974 to 1981, Gassée served as the Chief Executive Officer of the French affiliates of Data General and Exxon Office Systems.
In 1981, Gassée became Director of European Operations at Apple Computer. In 1985, after learning of Steve Jobs's plan to oust CEO John Sculley over Memorial Day weekend while Sculley was in China, Gassée preemptively informed the board of directors, which eventually led to Jobs's resignation from Apple.
Later, Sculley personally appointed Gassée to Jobs's old position as head of Macintosh development. Gassée introduced several Macintosh products on-stage in the late 1980s including the Macintosh Portable in 1989, and also the Macintosh IIfx. In his product introductions, he was often very comical. Gassée was less formal than many executives. He wore tailored suits when necessary, but he often addressed employees wearing a black (lambskin) leather jacket and a single diamond-stud earring .
When the idea of licensing the Mac OS for other companies use was brought up by various members of Apple, Jean-Louis refused to give in to the idea, maintaining that the Macintosh was more powerful than any other computer at the present, and had a superior architectural roadmap for future expansion than any other computer. Although many of the companies were interested (such as AT&T, for the use of the OS in their own equipment—they were so interested in this idea that the then-CEO of AT&T made a personal phone call to Sculley), Gassée would have none of it, and so the idea of licensing the Mac OS was shelved.
In the mid-1980s, Gassée started the skunkworks project to create what eventually became the Newton MessagePad.
In 1987, Apple CEO John Sculley published his memoir Odyssey. In the hope of inspiring "excellence," he ordered a hardback copy for each Apple employee, at Apple's expense. Shortly afterward, Gassée ordered a paperback copy of Fred Brooks's The Mythical Man-Month for all product-development employees, in the hope of inspiring good sense in project management. Brooks gave a lecture at nearby De Anza College: the room was filled with Apple employees with copies of his book, who told him stories that confirmed his conclusions.
In 1988, Gassée became head of Apple's advanced product development and worldwide marketing, and rumors of his taking over as president of Apple from |
https://en.wikipedia.org/wiki/CLIST | CLIST (Command List) (pronounced "C-List") is a procedural programming language for TSO in MVS systems. It originated in OS/360 Release 20 and has assumed a secondary role since the availability of Rexx in TSO/E Version 2. The term CLIST is also used for command lists written by users of NetView.
In its basic form, a CLIST program (or "CLIST" for short) can take the form of a simple list of commands to be executed in strict sequence (like a DOS batch file (*.bat) file). However, CLIST also features If-Then-Else logic as well as loop constructs.
CLIST is an interpreted language. That is, the computer must translate a CLIST every time the program is executed. CLISTs therefore tend to be slower than programs written in compiled languages such as COBOL, FORTRAN, or PL/1. (A program written in a compiled language is translated once to create a "load module" or executable.)
CLIST can read/write MVS files and read/write from/to a TSO terminal. It can read parameters from the caller and also features a function to hold global variables and pass them between CLISTs. A CLIST can also call an MVS application program (written in COBOL or PL/I, for example). CLISTs can be run in background (by running JCL which executes the TSO control program (IKJEFT01)). TSO I/O screens and menus using ISPF dialog services can be displayed by CLISTs.
Compare the function of CLIST with that provided by REXX.
Example programs
PROC 0
WRITE HELLO WORLD!
Adding If-Then-Else logic:
/********************************************************************/
/* MULTI-LINGUAL "HELLO WORLD" PROGRAM. */
/* */
/* THIS CLIST, STORED AS USERID.TSO.CLIST(TEST), CAN BE INVOKED */
/* FROM THE ISPF COMMAND LINE AS SHOWN IN THE FOLLOWING EXAMPLE: */
/* */
/* COMMAND ===> TSO TEST SPANISH */
/* */
/********************************************************************/
PROC 1 LANGUAGE
IF &LANGUAGE = SPANISH THEN +
WRITE HOLA, MUNDO
ELSE IF &LANGUAGE = FRENCH THEN +
WRITE BONJOUR, MONDE
ELSE +
WRITE HELLO, WORLD
EXIT
See also
Rexx
Footnotes
References
IBM mainframe operating systems
Procedural programming languages
Command shells
Text-oriented programming languages
Scripting languages |
https://en.wikipedia.org/wiki/Dynabook | The KiddiComp concept, envisioned by Alan Kay in 1968 while a PhD candidate, and later developed and described as the Dynabook in his 1972 proposal "A personal computer for children of all ages", outlines the requirements for a conceptual portable educational device that would offer similar functionality to that now supplied via a laptop computer or (in some of its other incarnations) a tablet or slate computer with the exception of the requirement for any Dynabook device offering near eternal battery life. Adults could also use a Dynabook, but the target audience was children.
Part of the motivation and funding for the Dynabook project came from the need for portable military maintenance, repair, and operations documentation. Eliminating the need to move large amounts of difficult-to-access paper in a dynamic military theatre provided significant US Department of Defense funding.
Though the hardware required to create a Dynabook is here today, Alan Kay still thinks the Dynabook hasn't been invented yet, because key software and educational curricula are missing. When Microsoft came up with its tablet PC, Kay was quoted as saying "Microsoft's Tablet PC, the first Dynabook-like computer good enough to criticize".
Toshiba also has a line of sub-notebook computers called DynaBooks. In June 2018, Sharp acquired a majority stake in Toshiba's PC business including laptops and tablets sold under the Dynabook brand.
Original concept
Describing the idea as "A Personal Computer For Children of All Ages", Kay wanted the Dynabook concept to embody the learning theories of Jerome Bruner and some of what Seymour Papert— who had studied with developmental psychologist Jean Piaget and who was one of the inventors of the Logo programming language — was proposing. This concept was created two years before the founding of Xerox PARC. The ideas led to the development of the Xerox Alto prototype, which was originally called "the interim Dynabook". It embodied all the elements of a graphical user interface, or GUI, as early as 1972. The software component of this research was Smalltalk, which went on to have a life of its own independent of the Dynabook concept.
The hardware on which the programming environment ran was relatively irrelevant.
At the same time, Kay tried in his 1972 article to identify existing hardware components that could be used in a Dynabook, including screens, processors and storage memory. For example:
The Dynabook vision was most fully laid out in Kay’s 1977 article "Personal Dynamic Media", co-authored with collaborator (and Smalltalk co-inventor) Adele Goldberg.
In 2019, Kay gave a detailed answer to a question on Quora, about the origins of the Dynabook concept.
Later works
Since the late 1990s, Kay has been working on the Squeak programming system, an open source Smalltalk-based environment which could be seen as a logical continuation of the Dynabook concept.
He was actively involved in the One Laptop Per Child project, w |
https://en.wikipedia.org/wiki/International%20Plant%20Names%20Index | The International Plant Names Index (IPNI) describes itself as "a database of the names and associated basic bibliographical details of seed plants, ferns and lycophytes." Coverage of plant names is best at the rank of species and genus. It includes basic bibliographical details associated with the names. Its goals include eliminating the need for repeated reference to primary sources for basic bibliographic information about plant names.
The IPNI also maintains a list of standardized author abbreviations. These were initially based on Brummitt & Powell (1992), but new names and abbreviations are continually added.
Description
IPNI is the product of a collaboration between The Royal Botanic Gardens, Kew (Index Kewensis), The Harvard University Herbaria (Gray Herbarium Index), and the Australian National Herbarium (APNI). The IPNI database is a collection of the names registered by the three cooperating institutions and they work towards standardizing the information. The standard of author abbreviations recommended by the International Code of Nomenclature for algae, fungi, and plants is Brummitt and Powell's Authors of Plant Names. A digital and continually updated list of authors and abbreviations can be consulted online at IPNI.
The IPNI provides names that have appeared in scholarly publications, with the objective of providing an index of published names rather than prescribing the accepted botanical nomenclature.
See also
Plants of the World Online
The Plant List
Index Fungorum
Multilingual Multiscript Plant Name Database
References
External links
of the IPNI – searchable for plant name, author name, publication
Botany books
Botanical nomenclature
Databases in the United Kingdom
Online botany databases
Online taxonomy databases
Royal Botanic Gardens, Kew |
https://en.wikipedia.org/wiki/Direct%20manipulation%20interface | In computer science, human–computer interaction, and interaction design, direct manipulation is an approach to interfaces which involves continuous representation of objects of interest together with rapid, reversible, and incremental actions and feedback. As opposed to other interaction styles, for example, the command language, the intention of direct manipulation is to allow a user to manipulate objects presented to them, using actions that correspond at least loosely to manipulation of physical objects. An example of direct manipulation is resizing a graphical shape, such as a rectangle, by dragging its corners or edges with a mouse.
Having real-world metaphors for objects and actions can make it easier for a user to learn and use an interface (some might say that the interface is more natural or intuitive), and rapid, incremental feedback allows a user to make fewer errors and complete tasks in less time, because they can see the results of an action before completing the action, thus evaluating the output and compensating for mistakes.
The term was introduced by Ben Shneiderman in 1982 within the context of office applications and the desktop metaphor. Individuals in academia and computer scientists doing research on future user interfaces often put as much or even more stress on tactile control and feedback, or sonic control and feedback than on the visual feedback given by most GUIs. As a result, the term has been more widespread in these environments.
In the contrast to WIMP/GUI interfaces
Direct manipulation is closely associated with interfaces that use windows, icons, menus, and a pointing device (WIMP GUI) as these almost always incorporate direct manipulation to at least some degree. However, direct manipulation should not be confused with these other terms, as it does not imply the use of windows or even graphical output. For example, direct manipulation concepts can be applied to interfaces for blind or vision-impaired users, using a combination of tactile and sonic devices and software.
Compromises to the degree to which an interface implements direct manipulation are frequently seen. For some examples, most versions of windowing interfaces allow users to reposition a window by dragging it with the mouse. In early systems, redrawing the window while dragging was not feasible due to computational limitations. Instead, a rectangular outline of the window was drawn while dragging. The complete window contents were redrawn once the user released the mouse button.
In computer graphics
Because of the difficulty of visualizing and manipulating various aspects of computer graphics, including geometry creation and editing, animation, the layout of objects and cameras, light placement, and other effects, direct manipulation is a significant part of 3D computer graphics. There is standard direct manipulation widgets as well as many unique widgets that are developed either as a better solution to an old problem or as a solution for |
https://en.wikipedia.org/wiki/External%20Data%20Representation | External Data Representation (XDR) is a standard data serialization format, for uses such as computer network protocols. It allows data to be transferred between different kinds of computer systems. Converting from the local representation to XDR is called encoding. Converting from XDR to the local representation is called decoding. XDR is implemented as a software library of functions which is portable between different operating systems and is also independent of the transport layer.
XDR uses a base unit of 4 bytes, serialized in big-endian order; smaller data types still occupy four bytes each after encoding. Variable-length types such as string and opaque are padded to a total divisible by four bytes. Floating-point numbers are represented in IEEE 754 format.
History
XDR was developed in the mid 1980s at Sun Microsystems, and first widely published in 1987.
XDR became an IETF standard in 1995.
The XDR data format is in use by many systems, including:
Network File System (protocol)
ZFS File System
NDMP Network Data Management Protocol
Open Network Computing Remote Procedure Call
Legato NetWorker backup software (later sold by EMC)
NetCDF (a scientific data format)
The R language and environment for statistical computing
The HTTP-NG Binary Wire Protocol
The SpiderMonkey JavaScript engine, to serialize/deserialize compiled JavaScript code
The Ganglia distributed monitoring system
The sFlow network monitoring standard
The libvirt virtualization library, API and UI
The Firebird (database server) for Remote Binary Wire Protocol
Stellar Payment Network
XDR data types
boolean
int – 32-bit integer
unsigned int – unsigned 32-bit integer
hyper – 64-bit integer
unsigned hyper – unsigned 64-bit integer
IEEE float
IEEE double
quadruple (new in RFC1832)
enumeration
structure
string
fixed length array
variable length array
union – discriminated union
fixed length opaque data
variable length opaque data
void – zero byte quantity
optional – optional data is notated similarly to C pointers, but is represented as the data type "pointed to" with a boolean "present or not" flag. Semantically this is option type.
See also
Structured Data eXchange Format (SDXF)
Remote Procedure Call
Abstract Syntax Notation One
Data Format Description Language
Comparison of data serialization formats
References
External links
The XDR standard exists in three different versions in the following RFCs:
2006 This document makes no technical changes to RFC 1832 and is published for the purposes of noting IANA considerations, augmenting security considerations, and distinguishing normative from informative references.
1995 version. Added Quadruple precision floating point to .
Cisco's XDR: Technical Notes
jsxdrapi.c, the main source file of SpiderMonkey that uses XDR
protocol.cpp main xdr source file used in Firebird remote protocol
The GNU Libc implementation of rpcgen, the XDR parser.
Mu Dynamics Research Labs racc grammar for XDR
|
https://en.wikipedia.org/wiki/Adjacency%20list | In graph theory and computer science, an adjacency list is a collection of unordered lists used to represent a finite graph. Each unordered list within an adjacency list describes the set of neighbors of a particular vertex in the graph. This is one of several commonly used representations of graphs for use in computer programs.
Implementation details
An adjacency list representation for a graph associates each vertex in the graph with the collection of its neighbouring vertices or edges. There are many variations of this basic idea, differing in the details of how they implement the association between vertices and collections, in how they implement the collections, in whether they include both vertices and edges or only vertices as first class objects, and in what kinds of objects are used to represent the vertices and edges.
An implementation suggested by Guido van Rossum uses a hash table to associate each vertex in a graph with an array of adjacent vertices. In this representation, a vertex may be represented by any hashable object. There is no explicit representation of edges as objects.
Cormen et al. suggest an implementation in which the vertices are represented by index numbers. Their representation uses an array indexed by vertex number, in which the array cell for each vertex points to a singly linked list of the neighboring vertices of that vertex. In this representation, the nodes of the singly linked list may be interpreted as edge objects; however, they do not store the full information about each edge (they only store one of the two endpoints of the edge) and in undirected graphs there will be two different linked list nodes for each edge (one within the lists for each of the two endpoints of the edge).
The object oriented incidence list structure suggested by Goodrich and Tamassia has special classes of vertex objects and edge objects. Each vertex object has an instance variable pointing to a collection object that lists the neighboring edge objects. In turn, each edge object points to the two vertex objects at its endpoints. This version of the adjacency list uses more memory than the version in which adjacent vertices are listed directly, but the existence of explicit edge objects allows it extra flexibility in storing additional information about edges.
Operations
The main operation performed by the adjacency list data structure is to report a list of the neighbors of a given vertex. Using any of the implementations detailed above, this can be performed in constant time per neighbor. In other words, the total time to report all of the neighbors of a vertex v is proportional to the degree of v
It is also possible, but not as efficient, to use adjacency lists to test whether an edge exists or does not exist between two specified vertices. In an adjacency list in which the neighbors of each vertex are unsorted, testing for the existence of an edge may be performed in time proportional to the minimum degree of the two given |
https://en.wikipedia.org/wiki/Herbarium | A herbarium (plural: herbaria) is a collection of preserved plant specimens and associated data used for scientific study.
The specimens may be whole plants or plant parts; these will usually be in dried form mounted on a sheet of paper (called exsiccatum, plur. exsiccata) but, depending upon the material, may also be stored in boxes or kept in alcohol or other preservative. The specimens in a herbarium are often used as reference material in describing plant taxa; some specimens may be types.
The same term is often used in mycology to describe an equivalent collection of preserved fungi, otherwise known as a fungarium. A xylarium is a herbarium specialising in specimens of wood. The term hortorium (as in the Liberty Hyde Bailey Hortorium) has occasionally been applied to a herbarium specialising in preserving material of horticultural origin.
History
The making of herbaria is an ancient phenomenon, at least six centuries old, although the techniques have changed little, and has been an important step in the transformation of the study of plants from a branch of medicine to an independent discipline, and to make available plant material from far away places and over a long period of time.
The oldest traditions of making herbarium collections have been traced to Italy. The Bologna physician and botanist, Luca Ghini (1490–1556) reintroduced the study of actual plants as opposed to relying on classical texts, such as Dioscorides, which lacked sufficient accuracy for identification. At first, he needed to make available plant material, even in winter, hence his Hortus hiemalis (winter garden) or Hortus siccus (dry garden). He and his students placed freshly gathered plants between two sheets of paper and applied pressure to flatten them and absorb moisture. The dried specimen was then glued onto a page in a book and annotated. This practice was supplemented by the parallel development of the Hortus simplicium or Orto botanico (botanical garden) to supply material, which he established at the University of Pisa in 1544.
Although Ghini's herbarium has not survived, the oldest extant herbarium is that of Gherardo Cibo from around 1532. While most of the early herbaria were prepared with sheets bound into books, Carl Linnaeus came up with the idea of maintaining them on free sheets that allowed their easy re-ordering within cabinets.
Specimen preservation
Commensurate with the need to identify the specimen, it is essential to include in a herbarium sheet as much of the plant as possible (e.g., roots, flowers, stems, leaves, seed, and fruit), or at least representative parts of them in the case of large specimens. To preserve their form and colour, plants collected in the field are carefully arranged and spread flat between thin sheets, known as flimsies (equivalent to sheets of newsprint), and dried, usually in a plant press, between blotters or absorbent paper.
During the drying process the specimens are retained within their flimsies at al |
https://en.wikipedia.org/wiki/4-H | 4-H is a U.S.-based network of youth organizations whose mission is "engaging youth to reach their fullest potential while advancing the field of youth development". Its name is a reference to the occurrence of the initial letter H four times in the organization's original motto head, heart, hands, and health, which was later incorporated into the fuller pledge officially adopted in 1927. In the United States, the organization is administered by the National Institute of Food and Agriculture of the United States Department of Agriculture (USDA). 4-H Canada is an independent non-profit organization overseeing the operation of branches throughout Canada. There are 4-H organizations in over 50 countries; the organization and administration varies from country to country.
The goal of 4-H is to develop citizenship, leadership, responsibility and life skills of youth through experiential learning programs and a positive youth development approach. Though typically thought of as an agriculturally focused organization as a result of its history, 4-H today focuses on citizenship, healthy living, science, engineering, and technology programs. Clubs in today's 4-H world consist of a wide range of options each allowing for personal growth and career success. The 4-H motto is "To make the best better", while its slogan is "Learn by doing" (sometimes written as "Learn to do by doing"). As of 2016, the organization had nearly 6 million active participants and more than 25 million alumni.
History
The foundations of 4-H began in 1902 with the work of several people in different parts of the United States. The focal point of 4-H has been the idea of practical and hands-on learning, which came from the desire to make public school education more connected to rural life. Early programs incorporated both public and private resources. 4-H was founded with the purpose of instructing rural youth in improved farming and farm-homemaking practices. By the 1970s, it was broadening its goals to cover a full range of youth, including minorities, and a wide range of life experiences.
During this time, researchers at experiment stations of the land-grant universities and USDA saw that adults in the farming community did not readily accept new agricultural discoveries. However, educators found that youth would experiment with these new ideas and then share their experiences and successes with the adults. Thus rural youth programs became a way to introduce new agriculture technology to the adults.
Club work began wherever a public-spirited person did something to give rural children respect for themselves and their ways of life and it is very difficult to credit one sole individual. Instances of work with rural boys and girls can be found all throughout the 19th century. In the spring of 1882, Delaware College announced a statewide corn contest for boys, in which each boy was to plant a quarter of an acre, according to instructions sent out from the college, and cash pri |
https://en.wikipedia.org/wiki/PCF | PCF may refer to:
1+3
Computing
PC Format, a monthly magazine
Percentage-closer filtering, a shadow mapping technique in computer graphics
Pivotal Cloud Foundry, a version of the open source Cloud Foundry software supported by Pivotal Software
Point coordination function, a media access control technique used in wireless LANs
Pair correlation function, a statistical tool to measure spatial correlation
Polymer-clad fiber, a type of optical fiber
Programming Computable Functions, a functional programming language
File formats
Physical Constraints File, a file format for the specification of FPGA
Portable Compiled Format, a file format for distributing bitmap fonts
Portable Content Format, a file format for DVB-based interactive television
Profile Configuration File, a configuration file used to set up VPN connections
Page configuration Format (Guidewire)
Technology
Photonic-crystal fiber
Pounds per cubic foot, a non-SI unit for density
Pivotal Cloud Foundry
Product carbon footprint method
Other
Pan-Canadian Framework on Clean Growth and Climate Change
PAP Community Foundation, Singapore charity
Parti Communiste Français, the French Communist party
Participatory Culture Foundation, U.S. charity to encourage individual political participation
Patrol Craft Fast or Swift Boat, used by U.S. Navy in the Vietnam War
PathCheck Foundation, COVID-19 Exposure Notification App
President's Choice Financial, Canadian financial service company
Prevent Cancer Foundation, U.S. charity
Princeton Christian Fellowship, campus ministry
Prostate Cancer Foundation, U.S. charity
People Can Fly, a video game developer
Port Canaveral, Florida, United States |
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