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https://en.wikipedia.org/wiki/Jech%E2%80%93Kunen%20tree | A Jech–Kunen tree is a set-theoretic tree with properties that are incompatible with the generalized continuum hypothesis. It is named after Thomas Jech and Kenneth Kunen, both of whom studied the possibility and consequences of its existence.
Definition
A ω1-tree is a tree with cardinality and height ω1, where ω1 is the first uncountable ordinal and is the associated cardinal number. A Jech–Kunen tree is a ω1-tree in which the number of branches is greater than and less than .
Existence
found the first model in which this tree exists, and showed that, assuming the continuum hypothesis and , the existence of a Jech–Kunen tree is equivalent to the existence of a compact Hausdorff space with weight and cardinality strictly between and .
References
Trees (set theory)
Independence results |
https://en.wikipedia.org/wiki/Central%20Institute%20of%20Fisheries%20Technology | The Central Institute of Fisheries Technology (CIFT) is an autonomous organization established by the government of India, engaged in research related to fishing and fish processing in the country. The institute has its headquarters in Matsyapuri, Willingdon Island, Kochi and is a subsidiary of Indian Council of Agricultural Research (ICAR), New Delhi, under the Ministry of Agriculture, India.
The Central Institute of Fisheries Technology (CIFT) was formed in 1954 and started functioning in 1957 from its headquarters in Kochi. It is considered to be the only institute where research facilities are available in all disciplines related to fishing and fish processing. CIFT is an ISO/IEC 17025:2005 NABL accredited and ISO 9001:2015 certified body.
CIFT has been selected as the seat for the establishment of the south zone Zonal Technology Management – Business Planning and Development (ZTM-BPD) Unit for catering to the individual and collective needs of 22 agricultural institutes of ICAR in south India.
Mandate
Basic and strategic research in fishing and processing, bioactive compounds & food safety
Design and develop energy efficient fishing systems for responsible fishing and sustainable management
Development of implements and machinery for fishing and fish processing
Human resource development through training, education and extension
Objectives
Basic and strategic research in fishing and processing.
Design and develop energy efficient fishing systems for responsible fishing and sustainable management
Development of implements and machinery for fishing and fish processing.
Human resource Development through training, education and extension.
Divisions
The institute has seven divisions that coordinates its activities across various disciplines.
Fishing Technology Division.
Fish Processing Division.
Biochemistry & Nutrition Division.
Quality Assurance & Management Division.
Engineering Division.
Extension, Information & Statistics Division.
|
https://en.wikipedia.org/wiki/Hunt%3A%20Showdown | Hunt: Showdown is a first-person shooter video game by Crytek. It was launched on Steam in early access on 22 February 2018 and for Xbox Game Preview on 29 May 2019. The full release of the game launched on 27 August 2019 for Microsoft Windows, it was also released on Xbox One on 19 September 2019 and PlayStation 4 on 18 February 2020. In the game, the player assumes the role of a bounty hunter who tries to kill mythical monsters in order to claim their bounties and survive long enough against other bounty hunters to reach an extraction point.
Hunt: Showdown was originally in development at Crytek USA, who wished to create a spiritual successor to Darksiders—a video game series developed by their predecessor, Vigil Games—under the title Hunt: Horrors of the Gilded Age. It was envisioned to be a cooperative multiplayer game. After the initial announcement in June 2014, Crytek USA was shut down due to financial issues, and the development was brought to the Crytek headquarters in Germany. The game, under the new title Hunt: Showdown, was re-announced in May 2017 and became a competitive multiplayer game in which players need to combat other players and enemies controlled by artificial intelligence in a large map that resembles an open world. The game received generally positive reviews upon release and was praised for its innovative gameplay loop. However, the game is notorious for its poor support of console versions.
Gameplay
Hunt: Showdown is a multiplayer first-person shooter with two gameplay modes. In "Bounty Hunt", the player plays as a bounty hunter who hunts down one or two of the game's 5 bosses to claim a bounty. Players can work on their own or with up to two other players to find clues about the monster's location in the three maps. Each map functions as a medium-sized open world filled with other environmental dangers and enemies such as Grunts, Hives, or Armoreds. As the player collects more clues, the location of the monster's lair is narrowed dow |
https://en.wikipedia.org/wiki/Digital%20fashion | Digital Fashion is the visual representation of clothing built using computer technologies and 3D software.
This industry is on the rise due to ethical awareness and uses of digital fashion technology such as artificial intelligence to create products with complex social and technical software.
Digital fashion is also the interplay between digital technology and couture. Human AI is an intersection of technology and human representation. Where human value is emphasized and enhanced by technology and the possibilities of discovering design. Information and communication technologies (ICTs) have been deeply integrated both into the fashion industry, as well as within the experience of clients and prospects. Such interplay has happened at three main levels.
ICTs are used to design and produce fashion products, while also the industry organization leverages onto digital technologies.
ICTs impact marketing, distribution and sales.
ICTs are extensively used in communication activities with all relevant stakeholders, and contribute to co-create the fashion world.
The fashion industry in general has paved the way for digital fashion to be introduced with more technology being in the industry like virtual dressing rooms and the gamification of the fashion industry. Digital fashion is also seen in many different online fashion retail websites. It may be seen on common websites you shop on. This evolution in the fashion industry has called for more education and research of digital fashion which will also be discussed in this article.
Design, production, and organization
Among the many applications available to fashion designers to model the fusion of creativity with digital avenues, the Digital Textile Printing can be mentioned here.
Digital textile printing
Digital textile printing has brought together the worlds of fashion, technology, art, chemistry, and printing to produce a new process for printing textiles on clothing.
Digital printing is a process in which prin |
https://en.wikipedia.org/wiki/Ohlson%20O-score | The Ohlson O-score for predicting bankruptcy is a multi-factor financial formula postulated in 1980 by Dr. James Ohlson of the New York University Stern Accounting Department as an alternative to the Altman Z-score for predicting financial distress.
Calculation of the O-score
The Ohlson O-score is the result of a 9-factor linear combination of coefficient-weighted business ratios which are readily obtained or derived from the standard periodic financial disclosure statements provided by publicly traded corporations. Two of the factors utilized are widely considered to be dummies as their value and thus their impact upon the formula typically is 0. When using an O-score to evaluate the probability of company’s failure, then exp(O-score) is divided by 1 + exp(O-score).
The calculation for Ohlson O-score appears below:
where
TA = total assets
GNP = gross national product price index level (in USD, 1968 = 100)
TL = total liabilities
WC = working capital
CL = current liabilities
CA = current assets
X = 1 if TL > TA, 0 otherwise
NI = net income
FFO = funds from operations
Y = 1 if a net loss for the last two years, 0 otherwise
Interpretation
The original model for the O-score was derived from the study of a pool of just over 2000 companies, whereas by comparison its predecessor the Altman Z-score considered just 66 companies. As a result, the O-score is significantly more accurate a predictor of bankruptcy within a 2-year period. The original Z-score was estimated to be over 70% accurate with its later variants reaching as high as 90% accuracy. The O-score is more accurate than this.
However, no mathematical model is 100% accurate, so while the O-score may forecast bankruptcy or solvency, factors both inside and outside of the formula can impact its accuracy. Furthermore, later bankruptcy prediction models such as the hazard based model proposed by Campbell, Hilscher, and Szilagyi in 2011 have proven more accurate still. For the O-score, any results la |
https://en.wikipedia.org/wiki/Test%20environment%20management | Test environment management (TEM) is a function in a software delivery process which aids the software testing cycle by providing a validated, stable and usable test environment to execute the test scenarios or replicate bugs.
Background
As with a scientific experiment, in Testing repeatability and control of variables is essential. In testing a key component of this control is to manage the environment in which testing is taking place. This environment specifically includes the underlying hardware and software which supports the actual software under test. This encompasses items such as servers, operating systems, communications tools, databases, cloud ecosystems browsers.
In early testing stages only limited formal management of environments is required, if any. For example programmers may typically perform their testing within standardised IDEs which provide control by default. However at later stages, test execution will tend to work across multiple technologies and development streams, and typically involving multiple (teams of) testers. In these circumstances individual testers cannot reasonably be expected to exercise control over the technical landscape. This is where the need for some formal Test Environment Management function arises.
Activities
The activities under the TEM function include:
Maintaining a central repository of test-environments in scope with their latest version and connectivity details (Information management)
Allocation of test environments (booking/scheduling) to teams as per requirement. (Demand management)
Creation of new test environments as per requirement. (Supply management)
Environment Monitoring (Monitoring)
Deleting/ updating outdated test-environments and its details (Housekeeping)
Preliminary investigation of issues on the environment and sometimes co-ordination till an issue resolution (Incident Management)
Analyzing data for environment issues, identifying trends and taking pro-active steps to resolve issues / c |
https://en.wikipedia.org/wiki/Reef%20Life%20Survey | Reef Life Survey is a marine life monitoring programme based in Hobart, Tasmania. It is international in scope, but predominantly Australian, as a large proportion of the volunteers are Australian. Most of the surveys are done by volunteer recreational divers, collecting biodiversity data for marine conservation. The database is available to marine ecology researchers, and is used by several marine protected area managements in Australia, New Zealand, American Samoa and the eastern Pacific.
Function
Reef Life Survey provides data to improve biodiversity conservation and the sustainable management of marine resources. They collect and curate biodiversity information at spatial and temporal scales beyond those possible by most scientific dive teams which have to work with limited resources, by using volunteer recreational divers trained in the RLS survey procedures. The University of Tasmania houses and manages the RLS database, and the data is freely available to the public for non-profit purposes through public outputs, including their website.
History
Reef Life Survey was started by researchers at the University of Tasmania and initially funded by the Commonwealth Environment Research Facilities (CERF) Program. This program is the core activity of the Reef Life Survey Foundation Incorporated – a not for profit Australian organisation.
Personnel
Reef Life Survey includes a volunteer network of recreational scuba divers, trained in the relevant skills, and an Advisory Committee. The advisory committee is made up of managers and scientists who use the collected data, and representatives of the recreational diver network.
Procedures
Standard survey procedures are used matched to a variety of habitat topographies, and using simple equipment - waterproof clipboard with records sheet, underwater camera, and 50m surveyor's tape measure. The surveys are typically repeated at irregular intervals at listed sites, identified by GPS location, transect depth and directio |
https://en.wikipedia.org/wiki/CastAR | castAR (formerly Technical Illusions) was a Palo Alto-based technology startup company founded in March 2013 by Jeri Ellsworth and Rick Johnson. Its first product was to be the castAR, a pair of augmented reality and virtual reality glasses. castAR was a founding member of the nonprofit Immersive Technology Alliance.
History
castAR was founded by two former Valve employees; the castAR glasses were born out of work that started inside Valve. While still at Valve, their team had spent over a year working on the project. They obtained legal ownership of their work after their departure.
In August 2015, Playground Global funded $15M into castAR to build its product and create augmented-reality experiences. In August 2016, Darrell Rodriguez, former President of LucasArts, joined as the new CEO. In addition, Steve Parkis became President and COO, after leading teams at The Walt Disney Company and Zynga. In September 2016, they opened castAR Salt Lake City, a new development studio formed from a team hired out of the former Avalanche Software, which worked on the Disney Infinity series.
In October 2016, they announced the acquisition of Eat Sleep Play, the developer best known for Twisted Metal, also in Salt Lake City UT.
In December 2016, Parkis, who had been President and COO, was named CEO to replace Rodriguez.
In June 2017 it was reported by Polygon that CastAR was shutting down, laying off 70 employees. A core group of administrators was expected to remain, to sell off the company's technology.
In September 2019 Jeri Ellsworth initiated a Kickstarter for a new device based on the same principles called Tilt Five. The company uses CastAR technology acquired from the former startup and is founded by CastAR alumni Jeri Ellsworth, Amy Herndon, Jamie Gennis, and Anthony Aquilio
castAR
The castAR glasses combine elements of augmented reality and virtual reality. After winning Educator's and Editor's Choice ribbons at the 2013 Bay Area Maker Faire, the castAR proje |
https://en.wikipedia.org/wiki/Building%20performance%20simulation | Building performance simulation (BPS) is the replication of aspects of building performance using a computer-based, mathematical model created on the basis of fundamental physical principles and sound engineering practice. The objective of building performance simulation is the quantification of aspects of building performance which are relevant to the design, construction, operation and control of buildings. Building performance simulation has various sub-domains; most prominent are thermal simulation, lighting simulation, acoustical simulation and air flow simulation. Most building performance simulation is based on the use of bespoke simulation software. Building performance simulation itself is a field within the wider realm of scientific computing.
Introduction
From a physical point of view, a building is a very complex system, influenced by a wide range of parameters. A simulation model is an abstraction of the real building which allows to consider the influences on high level of detail and to analyze key performance indicators without cost-intensive measurements. BPS is a technology of considerable potential that provides the ability to quantify and compare the relative cost and performance attributes of a proposed design in a realistic manner and at relatively low effort and cost. Energy demand, indoor environmental quality (incl. thermal and visual comfort, indoor air quality and moisture phenomena), HVAC and renewable system performance, urban level modeling, building automation, and operational optimization are important aspects of BPS.
Over the last six decades, numerous BPS computer programs have been developed. The most comprehensive listing of BPS software can be found in the BEST directory. Some of them only cover certain parts of BPS (e.g. climate analysis, thermal comfort, energy calculations, plant modeling, daylight simulation etc.). The core tools in the field of BPS are multi-domain, dynamic, whole-building simulation tools, which provide u |
https://en.wikipedia.org/wiki/Flexible%20Endoscopic%20Evaluation%20of%20Swallowing%20with%20Sensory%20Testing | Flexible Endoscopic Evaluation of Swallowing with Sensory Testing (FEESST), or laryngopharyngeal sensory testing, is a technique used to directly examine motor and sensory functions of swallowing so that proper treatment can be given to patients with swallowing difficulties to decrease their risk of aspiration (food and liquids going into the lungs instead of the stomach) and choking.
FEESST was invented by Dr. Jonathan E. Aviv MD, FACS in 1993, and has been used by otolaryngologists (ear, nose and throat doctors), pulmonologists (lung doctors), gastroenterologists (stomach and digestion doctors), intensivists (intensive care specialists) and speech-language pathologists for the past 20 years.
Swallowing consists of two distinct but interrelated processes: 1. Moving food and liquids from the mouth into the stomach through a set of coordinated muscle movements of the mouth larynx, pharynx and the esophagus 2. Protecting the airway to prevent food and liquids from entering the lungs.
This natural process of swallowing can be disrupted in many ways. The problem can occur when the movements involved in swallowing are restricted due to a tumor, any type of blockage, or paralysis after a stroke. Besides the motor problems, swallowing can be impaired due to sensory dysfunction, meaning when sensation (the ability to feel) is lost or reduced anywhere in the throat area. The loss of sensation can be caused by a problem originating in the brain, such as what happens after certain types of stroke, or it can be a result of a nerve injury or swelling in the actual throat area.
FEESST is the only test currently available which can identify if there is any loss of sensation in the throat area. Before FEESST was invented, all tests of swallowing, be they X-ray based tests (Modified Barium Swallow (MBS) or endoscopy-based tests (Fiberoptic Endoscopic Evaluation of Swallowing (FEES) solely looked at the motor component of swallowing without examining the sensory aspect of a swall |
https://en.wikipedia.org/wiki/Iterated%20forcing | In mathematics, iterated forcing is a method for constructing models of set theory by repeating Cohen's forcing method a transfinite number of times. Iterated forcing was introduced by in their construction of a model of set theory with no Suslin tree. They also showed that iterated forcing can construct models where Martin's axiom holds and the continuum is any given regular cardinal.
In iterated forcing, one has a transfinite sequence Pα of forcing notions indexed by some ordinals α, which give a family of Boolean-valued models VPα. If α+1 is a successor ordinal then Pα+1 is often constructed from Pα using a forcing notion in VPα, while if α is a limit ordinal then Pα is often constructed as some sort of limit (such as the direct limit) of the Pβ for β<α.
A key consideration is that, typically, it is necessary that is not collapsed. This is often accomplished by the use of a preservation theorem such as:
Finite support iteration of c.c.c. forcings (see countable chain condition) are c.c.c. and thus preserve .
Countable support iterations of proper forcings are proper (see Fundamental Theorem of Proper Forcing) and thus preserve .
Revised countable support iterations of semi-proper forcings are semi-proper and thus preserve .
Some non-semi-proper forcings, such as Namba forcing, can be iterated with appropriate cardinal collapses while preserving using methods developed by Saharon Shelah.
References
Sources
External links
Forcing (mathematics) |
https://en.wikipedia.org/wiki/30107%20KM | 30107 KM is the designation of Russian-built guyed tubular masts for FM-/TV-broadcasting, which were built in the first half of the 1960s at different places in Russia and Ukraine. The 30107 KM-mast has normally a 151 or 182.5 metres high mast body with a wall diameter of 16 – 10 mm, and exists in versions guyed in three and four directions.
Its most unusual feature however, which gives it its characteristic look are the crossbars equipped with a gangway with railing, which run in two levels from the mast structure to each outmost guy. These crossbars are used for oscillation damping of the structure and are used for the installation of antennas.
In the former Soviet Union, guyed tubular masts for broadcasting without these crossbars were also built. However such masts are not something special as such structures also exist in Germany, Czech, Slovakia, France, the United Kingdom, Japan, South Korea, Austria, Sweden, Slovenia and Poland.
30107 KM-masts with crossbars
Other guyed masts with tubular body in the former Soviet Union
External links
http://selenatel.ru/masts/masts-review/
Broadcasting standards
Antennas
Standards of Russia |
https://en.wikipedia.org/wiki/Time-triggered%20architecture | Time-triggered architecture (abbreviated as TTA), also known as a time-triggered system, is a computer system that executes one or more sets of tasks according to a pre-determined and set task schedule. Implementation of a TT system will typically involve use of a single interrupt that is linked to the periodic overflow of a timer. This interrupt may drive a task scheduler (a restricted form of real-time operating system). The scheduler willin turnrelease the system tasks at predetermined points in time.
History and development
Because they have highly deterministic timing behavior, TT systems have been used for many years to develop safety-critical aerospace and related systems.
An early text that sets forth the principles of time triggered architecture, communications, and sparse time approaches is Real-Time Systems: Design Principles for Distributed Embedded Applications in 1997.
Use of TT systems was popularized by the publication of Patterns for Time-Triggered Embedded Systems (PTTES) in 2001 and the related introductory book Embedded C in 2002. The PTTES book also introduced the concepts of time-triggered hybrid schedulers (an architecture for time-triggered systems that require task pre-emption) and shared-clock schedulers (an architecture for distributed time-triggered systems involving multiple, synchronized, nodes).
Since publication of PTTES, extensive research work on TT systems has been carried out.
Current applications
Time-triggered systems are now commonly associated with international safety standards such as IEC 61508 (industrial systems), ISO 26262 (automotive systems), IEC 62304 (medical systems) and IEC 60730 (household goods).
Alternatives
Time-triggered systems can be viewed as a subset of a more general event-triggered (ET) system architecture (see event-driven programming).
Implementation of an ET system will typically involve use of multiple interrupts, each associated with specific periodic events (such as timer overflows) |
https://en.wikipedia.org/wiki/Subhamiltonian%20graph | In graph theory and graph drawing, a subhamiltonian graph is a subgraph of a planar Hamiltonian graph.
Definition
A graph G is subhamiltonian if G is a subgraph of another graph aug(G) on the same vertex set, such that aug(G) is planar and contains a Hamiltonian cycle. For this to be true, G itself must be planar, and additionally it must be possible to add edges to G, preserving planarity,
in order to create a cycle in the augmented graph that passes through each vertex exactly once. The graph aug(G) is called a Hamiltonian augmentation of G.
It would be equivalent to define G to be subhamiltonian if G is a subgraph of a Hamiltonian planar graph, without requiring this larger graph to have the same vertex set. That is, for this alternative definition, it should be possible to add both vertices and edges to G to create a Hamiltonian cycle. However, if a graph can be made Hamiltonian by the addition of vertices and edges it can also be made Hamiltonian by the addition of edges alone, so this extra freedom does not change the definition.
In a subhamiltonian graph, a subhamiltonian cycle is a cyclic sequence of vertices such that adding an edge between each consecutive pair of vertices in the sequence preserves the planarity of the graph. A graph is subhamiltonian if and only if it has a subhamiltonian cycle.
History and applications
The class of subhamiltonian graphs (but not this name for them) was introduced by , who proved that these are exactly the graphs with two-page book embeddings. Subhamiltonian graphs and Hamiltonian augmentations have also been applied in graph drawing to problems involving embedding graphs onto universal point sets, simultaneous embedding of multiple graphs, and layered graph drawing.
Related graph classes
Some classes of planar graphs are necessarily Hamiltonian, and therefore also subhamiltonian; these include the 4-connected planar graphs and the Halin graphs.
Every planar graph with maximum degree at most four is subhamiltonian |
https://en.wikipedia.org/wiki/Terrainability | The terrainability of a machine or robot is defined as its ability to negotiate terrain irregularities.
Terrainability is a term coined in the research community and related to locomotion in the field of mobile robotics. Its various definitions generically describe the ability of the robot to handle various terrains in terms of their ground support, obstacle sizes and spacing, passive/dynamic stability, etc.
References
Robotics |
https://en.wikipedia.org/wiki/Artin%20transfer%20%28group%20theory%29 | In the mathematical field of group theory, an Artin transfer is a certain homomorphism from an arbitrary finite or infinite group to the commutator quotient group of a subgroup of finite index. Originally, such mappings arose as group theoretic counterparts of class extension homomorphisms of abelian extensions of algebraic number fields by applying Artin's reciprocity maps to ideal class groups and analyzing the resulting homomorphisms between quotients of Galois groups. However, independently of number theoretic applications, a partial order on the kernels and targets of Artin transfers has recently turned out to be compatible with parent-descendant relations between finite p-groups (with a prime number p), which can be visualized in descendant trees. Therefore, Artin transfers provide a valuable tool for the classification of finite p-groups and for searching and identifying particular groups in descendant trees by looking for patterns defined by the kernels and targets of Artin transfers. These strategies of pattern recognition are useful in purely group theoretic context, as well as for applications in algebraic number theory concerning Galois groups of higher p-class fields and Hilbert p-class field towers.
Transversals of a subgroup
Let be a group and be a subgroup of finite index
Definitions. A left transversal of in is an ordered system of representatives for the left cosets of in such that
Similarly a right transversal of in is an ordered system of representatives for the right cosets of in such that
Remark. For any transversal of in , there exists a unique subscript such that , resp. . Of course, this element with subscript which represents the principal coset (i.e., the subgroup itself) may be, but need not be, replaced by the neutral element .
Lemma. Let be a non-abelian group with subgroup . Then the inverse elements of a left transversal of in form a right transversal of in . Moreover, if is a normal subgroup of , then any |
https://en.wikipedia.org/wiki/MetaGer | MetaGer is a metasearch engine focused on protecting users' privacy. Based in Germany,
and hosted as a cooperation between the German NGO 'SUMA-EV - Association for Free Access to Knowledge' and the University of Hannover,
the system is built on 24 small-scale web crawlers under MetaGer's own control.
In September 2013, MetaGer launched MetaGer.net, an English-language version of their search engine.
Features
Search queries are relayed to as many as 50 search engines. The results are filtered, compiled and sorted before being presented to the user.
Users can select the search engines to query according to their individual choices among other options (such as "check for availability and sort by date"). MetaGer is free, but has a paid plan to remove all advertising. Users can create personal blacklists to filter out websites.
Privacy protection is implemented by several features:
MetaGer provides access to their services only through encrypted connections. As of December 2013, there is also a Tor Hidden Service that allows users to access the MetaGer search functionality from within the Tor network. Since February 2014 MetaGer additionally offers the option to open the result webpages anonymously ("open anonymously"). Unlike popular privacy search engines such as DuckDuckGo, MetaGer servers are not located in one of the Fourteen Eyes.
Since the 29th of August 2013 an English version of MetaGer is available. MetaGer's source code was released on GitLab at the 16th of August 2016.
References
External links
Internet search engines
Metasearch engines
Tor onion services |
https://en.wikipedia.org/wiki/RhodeCode | RhodeCode is an open source self-hosted platform for behind-the-firewall source code management. It provides centralized control over Git, Mercurial, and Subversion repositories within an organization, with common authentication and permission management. RhodeCode allows forking, pull requests, and code reviews via a web interface.
Software
RhodeCode is an enterprise source code management platform for Mercurial, Git, and SVN repositories. It also provides a web interface and APIs to control source code access, manage users, and conduct code reviews. The platform applies existing tools and integrations across the whole code base in a unified way.
RhodeCode is written in Python using the Pylons Framework. It is run as a standalone hosted application on a dedicated server (or in a private cloud) to manage multiple repositories within an organization. RhodeCode CE is free, with an unlimited number of users and repositories. RhodeCode EE is for-fee and builds enterprise integrations on top of CE.
Features
Team collaboration:
Advanced code reviews.
Side-by-side diffs.
Pull requests.
Inline source code chat.
Full-text code search and source code indexing.
Web-based file adding, editing, deletion.
Code snippets system (pastebin).
Repository management:
Unified support for Mercurial, Git, and Subversion.
Fine-grained user management and tools for the access control.
Advanced permission system with IP restrictions.
Code security and authentication:
Pluggable authentication system with tokens and LDAP support, Atlassian Crowd, Http-Headers, Pam.
Enterprise authentication options: Active Directory, GitHub/Google/Bitbucket authentication, 2-factor authentication.
Integration with 3rd party issue trackers and CI tools (Jira, Redmine, Jenkins, etc.)
Editions
RhodeCode platform comes in two editions:
RhodeCode CE (Community Edition) is free and open source. It is licensed under the terms of AGPLv3 license, with the source code openly available.
RhodeCode EE |
https://en.wikipedia.org/wiki/Friday%20Night%20Football%20%28NRL%29 | Friday Night Football is an Australian sports broadcast of National Rugby League games on Friday evenings.
In 1982, several early season NSWRL games were played on a Friday night, however regular non-weekend football began as Monday Night Football in 1985, with Canterbury meeting Manly on 24 June. However moderate attendances and a night game prior to a working day eventually saw the game shifted to Friday from 1988 on. As with Monday Night Football, regular Friday fixtures only commenced in the latter half of the season, due to the midweek competition. By 1990, a Friday night game was usually scheduled in all rounds.
The Friday night game is considered to be the most watched game of the week and many NRL clubs have openly stated that they appreciate the publicity given by these matches. The Nine Network choose the game they consider to be the "match of the round" 5 or 6 weeks in advance. This system has both positive and negative consequences, as it increases the likelihood of a good game played between two in-form sides, but does not allow fans or clubs a large amount of time to know on which day they will play in any given round.
Broadcast history
The Nine Network has broadcast Friday Night NRL games since 1992. From 2007 the Nine Network now broadcasts two NRL games in New South Wales, Queensland and the Australian Capital Territory on Friday Night - one live at 7.30, and the second match replayed at 9.30. Whichever of the two matches is televised first can depend on which teams are playing, for example, a match involving a Queensland-based team would in most cases be televised first into Queensland, and delayed in New South Wales; conversely, a match involving a New South Wales based team is usually televised first into New South Wales, and delayed in Queensland.
In the past, a Nine News or Nightline update separated the two broadcast matches, however in 2008 this was discontinued. In 2010, it was reinstated, before it was again scrapped.
From Round 5 of |
https://en.wikipedia.org/wiki/Preventable%20years%20of%20life%20lost | Preventable years of life lost (PrYLL) is an epidemiological measure. It is an estimate of the average years a person would have lived if s/he had not died prematurely due to a preventable cause of death.
PrYLL is closely related to potential years of life lost (PYLL) and like PYLL, it gives more weight than mortality rates to deaths that occur among younger people. Unlike PYLL, PrYLL excludes causes of death that aren't deemed to be preventable.
Premature deaths are those that could be avoided through public health interventions such as getting people to take more exercise or stop smoking, or in tackling the wider social determinants of health.
Causes of death can be classified using the International Classification of Diseases (ICD) codes. The United Kingdom’s Office for National Statistics (ONS) has published lists of ICD codes that are deemed to be avoidable, amenable and preventable. Within this publication, the ONS proposes the following definition for preventable causes of death: “A death is preventable if, in the light of current understanding of the determinants of health, all or most deaths from that cause (subject to age limits if appropriate) could be avoided by public health interventions in the broadest sense”.
History
PrYLL was developed in 2012 by Errol Taylor at The Royal Society for the Prevention of Accidents (RoSPA) to highlight the burden to society of accidental injury.
PrYLL features prominently in RoSPA’s Big Book of Accident Prevention and RoSPA’s guidance for local government decision-makers, which was supported by Public Health England(PHE) and funded by the UK Department of Health.
Calculation
To calculate the preventable years of life lost, the analyst has to set an upper reference age. This is essentially arbitrary and can be set, for example, to 65 to capture the whole population up to retirement, or 75 which, in developed countries, corresponds roughly to the life expectancy of the population being studied.
The analyst must th |
https://en.wikipedia.org/wiki/Plover-NET | Plover-NET, often misspelled Plovernet, was a popular bulletin board system in the early 1980s. Hosted in New York state and originally owned and operated by a teenage hacker who called himself Quasi-Moto, whom was a member of the short lived yet famed Fargo 4A phreak group. The popular bulletin board system attracted a large group of hackers, telephone phreaks, engineers, computer programmers, and other technophiles, at one point reaching over 600 users until LDX, a long distance phone company, began blocking all calls to its number (516-935-2481).
Naming and creation
The name Plover-NET came from a conversation between Quasi Moto, and Greg Schaefer. The topic of computer games came up. One of them, the 'Extended Adventure' game which was based on the 'Original Adventure' fantasy computer game was mentioned. This game was available on Compuserve and during game play the magic word PLOVER had to be used.
Past sysop of Plover-NET included Eric Corley, under the pseudonym Emmanuel Goldstein, and Lex Luthor, the founder of the notorious hacker group Legion of Doom.
Quasi-Moto personally recounted the creation of Plover-NET,
I met Lex in person while we lived in Florida during the Fall of 1983 after corresponding via email on local phreak boards. I was due to move to Long Island, New York (516 Area Code) soon after and asked him about starting up a phreak BBS. He agreed to help and flew up during his Christmas break from school in late December 1983. We worked feverishly for a couple of days to learn the GBBS Bulletin Board software which was to run on my Apple with a 300 baud Hayes micoSLOWdom %micromodem% and make modifications as necessary. The system accepted its first phone call from Lex in the first week of January 1984 and it became chronically busy soon after.
Legion of Doom
Lex Luthor, under the age of 18 at the time, was a COSMOS (Central System for Mainframe Operations) expert, when he operated Plover-NET. At the time there were a few hacking groups i |
https://en.wikipedia.org/wiki/Enterprise%20interoperability%20framework | The enterprise interoperability framework is used as a guideline for collecting and structuring knowledge/solution for enterprise interoperability. The framework defines the domains and sub-domains for interoperability research and development in order to identify a set of pieces of knowledge for solving enterprise interoperability problems by removing barriers to interoperability.
Existing interoperability frameworks
Some existing works on interoperability have been carried out to define interoperability framework or reference models, in particular, the LISI reference model, European Interoperability Framework (EIF), IDEAS interoperability framework, ATHENA interoperability framework, and E-Health Interoperability Framework. These existing approaches constitute the basis for the enterprise interoperability framework.
Existing interoperability frameworks do not explicitly address barriers to interoperability, which is a basic assumption of this research; they are not aimed at structuring interoperability knowledge with respect to their ability to remove various barriers.
The enterprise Interoperability framework has three basic dimensions:
Interoperability concerns define the content (or aspect) of interoperation that may take place at various levels of the enterprise. In the domain of Enterprise Interoperability, the following four interoperability concerns are identified: data, service, process, and business.
Interoperability barriers: Interoperability barrier is a fundamental concept in defining the interoperability domain. Many interoperability issues are specific to particular application domains. These can be things like support for particular attributes or particular access control regimes. Nevertheless, general barriers and problems of interoperability can be identified; and most of them being already addressed, Consequently, the objective is to identify common barriers to interoperability. By the term ‘barrier’ we mean an ‘incompatibility’ or ‘misma |
https://en.wikipedia.org/wiki/1QBit | 1QB Information Technologies, Inc. (1QBit) is a quantum computing software company, based in Vancouver, British Columbia. 1QBit was founded on December 1, 2012 and has established hardware partnerships with Microsoft, IBM, Fujitsu and D-Wave Systems. While 1QBit develops general purpose algorithms for quantum computing hardware, the organization is primarily focused on computational finance, materials science, quantum chemistry, and the life sciences.
Technology
1QBit has divisions focused on universal quantum computing, advanced AI techniques, cloud based quantum processing, and hardware innovation.
1QBit's 1Qloud platform is focused on optimization including reformulating optimization problems into the quadratic unconstrained binary optimization (QUBO) format necessary to compute with quantum annealing processors and similar devices from organizations such as Fujitsu, D-Wave, Hitachi and NTT, while their QEMIST platform is focused on advanced materials and quantum chemistry research with universal quantum computing processors.
History
1QBit was founded as the first dedicated quantum computing software company in 2012. In 2013, 1QBit raised seed funding from US and Canadian angel investors, before closing a Series A financing round led by the Chicago Mercantile Exchange in 2014.
On August 5, 2015 the World Economic Forum announced 1QBit as a recipient of the 2015 Technology Pioneer Award recognizing 1QBit as a leader among the world's most promising technology companies. In 2017, 1QBit raised a $45M Series B financing round led by Fujitsu with participation from Allianz, Accenture, The Royal Bank of Scotland and the Chicago Mercantile Exchange. In April 2018, 1QBit joined the IBM Q Network, a global community of leading Fortune 500 companies, academic institutions, startups, and national research labs designed to explore practical applications for quantum computing.
In May 2020, 1QBit and its collaborators serving health authorities from East to West obtained |
https://en.wikipedia.org/wiki/FlowVella | FlowVella (formerly Flowboard) is an interactive presentation platform that includes an iPad/iPhone app, a Mac app and web site for viewing presentations, built first for the iPad and web. FlowVella allows users to create, publish and share presentations through their cloud-based SaaS system. FlowVella allows embedding of text, images, PDFs, video and gallery objects in easy linkable screens, defining modern interactive presentations. FlowVella grew out of Treemo Labs.
History
FlowVella launched as 'Flowboard' on April 18, 2013 after being built for almost a year. FlowVella was incubated out of Treemo Labs, which had years of experience building native apps for iPhone, iPad and Android devices. FlowVella is an iPad app and Mac app where users create, view, publish and share interactive presentations. Presentations are viewable on flowvella.com through a web-based viewer on any device or through the FlowVella native iPad app or Mac app.
On December 18, 2014, Flowboard rebranded as FlowVella after a trademark dispute.
Presentation format
FlowVella is an interactive presentation format where instead of single directional slides, presentations are made up of linkable screens with embeddable media and content objects. While 'Flows' can be exported to PDF, they all have a web address and are meant to be viewed via a web browser or the FlowVella native applications.
Revenue model
FlowVella uses the freemium model for its presentation apps. Free users can make 4 public presentations with limited number of screens/slides, but most features are available to try out the software. In 2016, FlowVella introduced a second paid plan called PRO which includes team sharing, tracking and newly introduced 'Kiosk Mode' that launched in March of 2017.
Features
FlowVella is a native iPad app and Mac app which has advantages over web based tools. All downloaded presentations can be viewed offline, without an Internet connection. This includes videos which are enabled by cachin |
https://en.wikipedia.org/wiki/Thickness%20%28graph%20theory%29 | In graph theory, the thickness of a graph is the minimum number of planar graphs into which the edges of can be partitioned. That is, if there exists a collection of planar graphs, all having the same set of vertices, such that the union of these planar graphs is , then the thickness of is at most . In other words, the thickness of a graph is the minimum number of planar subgraphs whose union equals to graph .
Thus, a planar graph has thickness 1. Graphs of thickness 2 are called biplanar graphs. The concept of thickness originates in the Earth–Moon problem on the chromatic number of biplanar graphs, posed in 1959 by Gerhard Ringel, and on a related 1962 conjecture of Frank Harary: For any graph on 9 points, either itself or its complementary graph is non-planar. The problem is equivalent to determining whether the complete graph is biplanar (it is not, and the conjecture is true). A comprehensive survey on the state of the arts of the topic as of 1998 was written by Petra Mutzel, Thomas Odenthal and Mark Scharbrodt.
Specific graphs
The thickness of the complete graph on vertices, , is
except when for which the thickness is three.
With some exceptions, the thickness of a complete bipartite graph is generally:
Properties
Every forest is planar, and every planar graph can be partitioned into at most three forests. Therefore, the thickness of any graph is at most equal to the arboricity of the same graph (the minimum number of forests into which it can be partitioned) and at least equal to the arboricity divided by three.
The graphs of maximum degree have thickness at most . This cannot be improved: for a -regular graph with girth at least , the high girth forces any planar subgraph to be sparse, causing its thickness to be exactly .
Graphs of thickness with vertices have at most edges. Because this gives them average degree less than , their degeneracy is at most and their chromatic number is at most . Here, the degeneracy can be defined as the |
https://en.wikipedia.org/wiki/Applied%20Mathematics%20and%20Mechanics%20%28English%20Edition%29 | Applied Mathematics and Mechanics (English Edition) is a peer-reviewed journal of mechanics, established in 1980 by Wei-zang Chien in 1980. Chien was the editor-in-chief from 1980 to 2002 and subsequently an honorary editor-in-chief. Xingming Guo is the editor-in-chief now. In 1980, it was quarterly, became bimonthly in 1981, and then monthly in 1985.
Abstracting and indexing
The journal is abstracted and indexed in the following bibliographic databases:
According to the Journal Citation Reports, it has a 2016 impact factor of 1.205.
References
External links
Academic journals established in 1980
Monthly journals
English-language journals |
https://en.wikipedia.org/wiki/SMPTE%202071 | SMPTE ST 2071 is a suite of standards published by the Society of Motion Picture and Television Engineers (SMPTE) that define a framework, protocol, and method of service discovery for the control of objects within an Internet of Things. The standards focus on the interoperability and discoverability of objects within the network, and treat media as first-class citizen. The standard also describes a programming methodology that allows objects to describe their behaviors (features) to other objects over the network and allows objects to change their behavior dynamically at runtime. Application developers developing to the SMPTE ST 2071 standards focus on writing their applications to the behaviors they wish to support and not the object or class of object that implements those behaviors.
Media as a first-class citizen
The SMPTE ST 2071 standards define media as a first-class citizen, changing the focus from controlling devices and services to controlling media. This paradigm shift provides a more natural method of discovering, managing, and manipulating media as it harmonizes the way media is controlled with the way that it is conceptually perceived.
Features as first-class citizens
The SMPTE ST 2071 standards define a development methodology that elevates features to a first-class citizen status, allowing for those features to be decoupled from the objects that implement them. The standard defines capabilities as uniquely identified features that may be defined through normative prose and/or interface definition languages, such as OMG IDL or WSDL, and consequently documented or registered within a repository to foster feature-level interoperability within heterogeneous environments.
Interoperability and new applications
The interoperable exchange of media requires common file formats, compression/encoding techniques, transport mechanisms, semantics, and a common means by which media can be discovered, located, accessed, and managed. The SMPTE ST 2071 suite o |
https://en.wikipedia.org/wiki/Psychology%27s%20Feminist%20Voices | Psychology's Feminist Voices (PFV) is an online, multimedia digital archive containing the stories of women of psychology's past and contemporary feminist psychologists who have shaped and continue to transform the discipline of psychology. It houses a wide range of materials, including original biographical profiles, oral history interview transcripts, video content, timelines, bibliographies, teaching resources, and an original 40-minute documentary on the emergence and current status of feminist psychology in the United States. The project is continually expanding and currently has a database containing the profiles of over 250 psychologists from around the world.
PFV is also an online teaching resource, with sample syllabi for teaching history of psychology from a feminist perspective, teaching guides for incorporating PFV material into history and psychology of gender courses, assignments, handouts, and teaching videos.
PFV is a free resource and all interview transcripts are downloadable as .pdf files; all video content is available at the site and at the psychsfeministvoices YouTube channel; all interview transcripts are copyrighted to Feminist Voices except where indicated.
History
The Psychology's Feminist Voices project was founded by Alexandra Rutherford in 2004. It began as a collection of oral histories with contemporary feminist psychologists, many of whom established the field of feminist psychology in the United States and Canada in the early 1970s. It quickly expanded, however, to encompass a larger goal: the documentation of women throughout psychology's history, as well as a large and diverse sample of feminist psychologists in order to create a comprehensive picture of the impact of gender, women's participation, and feminism, on the development of psychology as a science and profession. The online resource, www.feministvoices.com, was launched in 2010 and now has a corresponding Facebook site, YouTube channel, and Twitter feed.
This |
https://en.wikipedia.org/wiki/Falcon%209%20first-stage%20landing%20tests | The Falcon 9 first-stage landing tests were a series of controlled-descent flight tests conducted by SpaceX between 2013 and 2016. Since 2017, the first stage of Falcon 9 missions has been routinely landed if the rocket performance allowed it, and if SpaceX chose to recover the stage.
The program's objective was to reliably execute controlled re-entry, descent and landing (EDL) of the Falcon 9 first stage into Earth's atmosphere after the stage completes the boost phase of an orbital spaceflight. The first tests aimed to touch down vertically in the ocean at zero velocity. Later tests attempted to land the rocket precisely on an autonomous spaceport drone ship (a barge commissioned by SpaceX to provide a stable landing surface at sea) or at Landing Zone 1 (LZ-1), a concrete pad at Cape Canaveral. The first ground landing at LZ-1 succeeded in December 2015, and the first landing at sea on a drone ship in April 2016. The second landed booster, B1021, was the first to fly again in March 2017, and was recovered a second time.
Landings of Falcon 9 first-stage boosters
Overview
The first landing test occurred in September 2013 on the sixth flight of a Falcon 9 and maiden launch of the v1.1 rocket version. From 2013 to 2016, sixteen test flights were conducted, six of which achieved a soft landing and recovery of the booster:
flight 20 (Orbcomm OG2 M2) safely touching down on the LZ-1 ground pad upon first attempt in December 2015;
flight 23 (CRS-8) finally achieving a stable landing at sea in the Atlantic on the drone ship Of Course I Still Love You in April 2016 after four previous attempts ended in destruction of the booster upon impact;
flights 24 (JCSAT-14) and 25 (Thaicom 8) returning at higher speed from GTO missions at sea on a drone ship in May 2016;
flight 27 (CRS-9) returning to LZ-1 in July 2016;
flight 28 (JCSAT-16) landing on a drone ship in August 2016;
Since the January 2017 return to flight, SpaceX has stopped referring to landing attempts as "ex |
https://en.wikipedia.org/wiki/Formal%20ball | In topology, a formal ball is an extension of the notion of ball to allow unbounded and negative radius. The concept of formal ball was introduced by Weihrauch and Schreiber in 1981 and the negative radius case (the generalized formal ball) by Tsuiki and Hattori in 2008.
Specifically, if is a metric space and the nonnegative real numbers, then an element of is a formal ball. Elements of are known as generalized formal balls.
Formal balls possess a partial order defined by if , identical to that defined by set inclusion.
Generalized formal balls are interesting because this partial order works just as well for as for , even though a generalized formal ball with negative radius does not correspond to a subset of .
Formal balls possess the Lawson topology and the Martin topology.
References
K. Weihrauch and U. Schreiber 1981. "Embedding metric spaces into CPOs". Theoretical computer science, 16:5-24.
H. Tsuiki and Y. Hattori 2008. "Lawson topology of the space of formal balls and the hyperbolic topology of a metric space". Theoretical computer science, 405:198-205
Y. Hattori 2010. "Order and topological structures of posets of the formal balls on metric spaces". Memoirs of the Faculty of Science and Engineering. Shimane University. Series B 43:13-26
Topology |
https://en.wikipedia.org/wiki/Batch%20cryptography | Batch cryptography is the area of cryptology where cryptographic protocols are studied and developed for doing cryptographic processes like encryption/decryption, key exchange, authentication, etc. in a batch way instead of one by one. The concept of batch cryptography was introduced by Amos Fiat in 1989.
References
Cryptography |
https://en.wikipedia.org/wiki/Key%20checksum%20value | In cryptography, a Key Checksum Value (KCV) is the checksum of a cryptographic key. It is used to validate the key integrity or compare keys without knowing their actual values. The KCV is computed by encrypting a block of bytes, each with value '00' or '01', with the cryptographic key and retaining the first 6 hexadecimal characters of the encrypted result. It is used in key management in different ciphering devices, like SIM-cards or Hardware Security Modules (HSM).
In the GlobalPlatform technical specifications the KCV is defined for DES/3DES and AES keys as follows:
The same definition is used by the GSMA.
KCV for symmetric key management in retail financial services
The payments cards industry uses the following definition, as documented in requirement 15-1 of PCI PIN Security standard. The same definitions can also be found in the ASC X9 standards under ANSI x9.24-1-2017 Retail Financial Services Symmetric Key Management Part 1Check values may be computed by two methods. TDEA may use either method. AES must only use the CMAC method. In the first method, check values are computed by encrypting an all binary zeros block using the key or component as the encryption key, using the leftmost n-bits of the result; where n is at most 24 bits (6 hexadecimal digits/3 bytes). In the second method the KCV is calculated by MACing an all binary zeros block using the CMAC algorithm as specified in ISO 9797-1 (see also NIST SP 800-38B). The check value will be the leftmost n-bits of the result, where n is at most 40 bits (10 hexadecimal digits). The block cipher used in the CMAC function is the same as the block cipher of the key itself. A TDEA key or a component of a TDEA key will be MACed using the TDEA block cipher, while a 128-bit AES key or component will be MACed using the AES-128 block cipher.
References
Key management |
https://en.wikipedia.org/wiki/Time/memory/data%20tradeoff%20attack | A time/memory/data tradeoff attack is a type of cryptographic attack where an attacker tries to achieve a situation similar to the space–time tradeoff but with the additional parameter of data, representing the amount of data available to the attacker. An attacker balances or reduces one or two of those parameters in favor of the other one or two. This type of attack is very difficult, so most of the ciphers and encryption schemes in use were not designed to resist it.
History
Tradeoff attacks on symmetric cryptosystems date back to 1980, when Martin Hellman suggested a time/memory tradeoff method to break block ciphers with possible keys in time and memory related by the tradeoff curve where . Later, in 1995, Babbage and Golic devised a different tradeoff attack for stream ciphers with a new bound such that for where is the output data available to the cryptanalyst at real time.
Attack mechanics
This attack is a special version of the general cryptanalytic time/memory tradeoff attack, which has two main phases:
Preprocessing: During this phase, the attacker explores the structure of the cryptosystem and is allowed to record their findings in large tables. This can take a long time.
Realtime: In this phase, the cryptanalyst is granted real data obtained from a specific unknown key. They then try to use this data with the precomputed table from the preprocessing phase to find the particular key in as little time as possible.
Any time/memory/data tradeoff attack has the following parameters:
search space size
time required for the preprocessing phase
time required for the realtime phase
amount of memory available to the attacker
amount of realtime data available to the attacker
Hellman's attack on block ciphers
For block ciphers, let be the total number of possible keys and also assume the number of possible plaintexts and ciphertexts to be . Also let the given data be a single ciphertext block of a specific plaintext counterpart. If we co |
https://en.wikipedia.org/wiki/Behavior%20tree%20%28artificial%20intelligence%2C%20robotics%20and%20control%29 | A behavior tree is a mathematical model of plan execution used in computer science, robotics, control systems and video games. They describe switchings between a finite set of tasks in a modular fashion. Their strength comes from their ability to create very complex tasks composed of simple tasks, without worrying how the simple tasks are implemented. Behavior trees present some similarities to hierarchical state machines with the key difference that the main building block of a behavior is a task rather than a state. Its ease of human understanding make behavior trees less error prone and very popular in the game developer community. Behavior trees have been shown to generalize several other control architectures.
Background
A behavior based control structure has been initially proposed by Rodney Brooks in his paper titled 'A robust layered control system for a mobile robot'. In the initial proposal a list of behaviors could work as alternative one another, later the approach has been extended and generalized in a tree-like organization of behaviors, with extensive application in the game industry as a powerful tool to model the behavior of non-player characters (NPCs).
They have been extensively used in high-profile video games such as Halo, Bioshock, and Spore. Recent works propose behavior trees as a multi-mission control framework for UAV, complex robots, robotic manipulation, and multi-robot systems.
Behavior trees have now reached the maturity to be treated in Game AI textbooks, as well as generic game environments such as Unity (game engine) and Unreal Engine (see links below).
Behavior trees became popular for their development paradigm: being able to create a complex behavior by only programming the NPC's actions and then designing a tree structure (usually through drag and drop) whose leaf nodes are actions and whose inner nodes determine the NPC's decision making. Behavior trees are visually intuitive and easy to design, test, and debug, and provide m |
https://en.wikipedia.org/wiki/Hetzner | Hetzner Online GmbH is a company and data center operator based in Gunzenhausen, Bavaria, in Germany.
History
Hetzner Online GmbH (Gesellschaft mit beschränkter Haftung) began operations in Germany in 1997 under the name Hetzner Online Services. Between 2000 and 2015, Hetzner Online in Germany operated under the legal status AG ("Aktiengesellschaft"). In 2015, it changed its legal status to GmbH. In addition, Hetzner Online expanded its chief executive team with Stephan Konvickova and Günther Müller at the beginning of the year 2019.
The company is named after its founder Martin Hetzner. Hetzner Online owns and operates four data center parks in Nuremberg and Falkenstein (Germany), Tuusula (Finland), and Ashburn, Virginia (United States). In addition, Hetzner Online is a co-investor in the Cinia C-Lion1 project, which connected Helsinki and Rostock, Germany together with a 1,100 km long submarine fiberglass cable. The cable provides a high-speed connection between Hetzner's German and Finnish data centers.
Services
Hetzner Online provides dedicated hosting, shared web hosting, virtual private servers, managed servers, domain names, SSL certificates, storage boxes, and cloud. At the data center parks located in Nuremberg, Falkenstein and Tuusula/Finland, customers can also connect their hardware to Hetzner Online's infrastructure and network with the company's colocation services. The company operates a server auction site online where the chance to rent older dedicated servers (not purchase or colocate) are auctioned off in the form of a Dutch auction.
Hetzner Online has a domain name registrar arrangement with ICANN (for registering domains under .com, .net and .org and others), DENIC (for .de), and nic.at (for .at).
Infrastructure
Hetzner Online's datacenter projects are coordinated and implemented in-house with as little outsourcing as possible. Data center units served by multiple redundant uplinks, including 1300 Gbit/s to DE-CIX and fiber optic links to N |
https://en.wikipedia.org/wiki/Embedded%20controller | An Embedded Controller (EC) is a microcontroller in computers that handles various system tasks. Now it is usually merged with Super I/O, especially on mobile platforms (such as laptop).
Tasks
An embedded controller can have the following tasks:
Receiving and processing signals from the keyboard and the touchpad (including touchpad disable)
Other buttons and switches (e.g., power button, laptop lid switch (received from hall sensor))
Controlling access to the A20 line
Thermal measurement (CPU, GPU, Motherboard) and response including fan control, CPU and GPU throttling, and emergency shutdown in response to rising temperatures
Controlling indicator LEDs (e.g. caps lock, scroll lock, num lock, battery, ac, power, wireless LAN, sleep)
Managing the battery charger and the battery
Allowing remote diagnostics and remediation over the network
Performing software-requested CPU reset
Controlling the watchdog timer
System Management Interrupt (entry to System Management Mode)
Bluetooth toggle
Display backlight toggle
USB OC (overcurrent) (USB disable)
Display power toggle
Controls RGB lighting
eSATA toggle
Wake-on-LAN
Debug Card Interface (Enables repair centers to monitor the boot process with a special device in an attempt to fix problems)
SCI from the Embedded Controller to inform the ACPI driver (in the ) of an ACPI Event
As a core system component, the embedded controller is always on when power is supplied to the mainboard. To communicate with the main computer system, several forms of communication can be used, including ACPI, SMBus, or shared memory.
The embedded controller has its own RAM, independent of that used by the main computer system, and often its own flash ROM on which the controller's software is stored. Many BIOS updates also include upgrades for the embedded controller firmware.
An embedded controller is sometimes known as a "Keyboard Controller BIOS", which comes from the fact that the embedded controller evolved from the keyboard controller and |
https://en.wikipedia.org/wiki/SecureSafe | SecureSafe is a cloud based software-as-a-service with a password safe, a document storage and digital spaces for online collaboration. The service is developed based on the principles of security by design and privacy by design.
Data centers
SecureSafe stores customers’ data in three data centers using triple redundancy mirroring. The first data center is dedicated to production, the second is a hot standby and the third acts as the so-called disaster recovery center. The first two data centers are located in the greater area of Zürich at the company Interxion. The third center is located in a former military bunker in the mountains of central Switzerland.
Features
Password manager
A password manager is used to store passwords. The passwords that are stored in SecureSafe are protected by AES-256 and RSA-2048 encryption.
File storage
A file storage or cloud storage is used to store files online.
2-factor authentication
The login method 2-factor authentication is also known from e-banking systems. It works by sending a one-time code to a user’s mobile every time he or she logs into a given online account. Even if a hacker should get to the user’s login data, the information is useless without the additional security code.
Data rooms
Data rooms are digital spaces where groups of people can share data online.
Data inheritance
Data inheritance or digital inheritance enables customers to pass on important digital assets to others. Among the digital assets people pass on is login criteria to online accounts, insurance and legal documents and photo collections.
References
External links
File hosting
Data synchronization
Cloud storage
File hosting for macOS
File hosting for Windows
Companies' terms of service |
https://en.wikipedia.org/wiki/Principalization%20%28algebra%29 | In the mathematical field of algebraic number theory, the concept of principalization refers to a situation when, given an extension of algebraic number fields, some ideal (or more generally fractional ideal) of the ring of integers of the smaller field isn't principal but its extension to the ring of integers of the larger field is. Its study has origins in the work of Ernst Kummer on ideal numbers from the 1840s, who in particular proved that for every algebraic number field there exists an extension number field such that all ideals of the ring of integers of the base field (which can always be generated by at most two elements) become principal when extended to the larger field. In 1897 David Hilbert conjectured that the maximal abelian unramified extension of the base field, which was later called the Hilbert class field of the given base field, is such an extension. This conjecture, now known as principal ideal theorem, was proved by Philipp Furtwängler in 1930 after it had been translated from number theory to group theory by Emil Artin in 1929, who made use of his general reciprocity law to establish the reformulation. Since this long desired proof was achieved by means of Artin transfers of non-abelian groups with derived length two, several investigators tried to exploit the theory of such groups further to obtain additional information on the principalization in intermediate fields between the base field and its Hilbert class field. The first contributions in this direction are due to Arnold Scholz and Olga Taussky in 1934, who coined the synonym capitulation for principalization. Another independent access to the principalization problem via Galois cohomology of unit groups is also due to Hilbert and goes back to the chapter on cyclic extensions of number fields of prime degree in his number report, which culminates in the famous Theorem 94.
Extension of classes
Let be an algebraic number field, called the base field, and let be a field extension of |
https://en.wikipedia.org/wiki/Post-Internet | Post-Internet is a 21st-century art movement involving works that are derived from the Internet or its effects on aesthetics, culture and society.
Definition
Post-Internet is a loosely-defined term that was coined by artist/curator Marisa Olson in an attempt to describe her practice. It emerged from mid-2000s discussions about Internet art by Gene McHugh (author of a blog titled "Post-Internet"), and Artie Vierkant (artist, and creator of Image Object sculpture series). The movement itself grew out of Internet Art (or Net Art). According to the UCCA Center for Contemporary Art in Beijing, rather than referring "to a time “after” the internet", the term refers to "an internet state of mind". Eva Folks of AQNB wrote that it "references one so deeply embedded in and propelled by the internet that the notion of a world or culture without or outside it becomes increasingly unimaginable, impossible."
The term is controversial and the subject of much criticism in the art community. Art in Americas Brian Droitcour in 2014 opined that the term fails to describe the form of the works, instead "alluding only to a hazy contemporary condition and the idea of art being made in the context of digital technology." According to a 2015 article in The New Yorker, the term describes "the practices of artists [whose] artworks move fluidly between spaces, appearing sometimes on a screen, other times in a gallery." Fast Companys Carey Dunne summarizes they are "artists who are inspired by the visual cacophony of the web" and notes that "mediums from Second Life portraits to digital paintings on silk to 3-D-printed sculpture" are used.
There is theoretical overlap with writer and artist James Bridle's term New Aesthetic. Ian Wallace of Artspace writes that "the influential blog The New Aesthetic, run since May 2011 by Bridle, is a pioneering institution in the post-Internet movement" and concludes that "much of the energy around the New Aesthetic seems, now, to have filtered over into t |
https://en.wikipedia.org/wiki/Building%20Performance%20Database | The Building Performance Database (BPD) is an anonymized database that contains energy use intensity data for hundreds of thousands of buildings in the United States. It is built by the Department of Energy in the United States and maintained by the Lawrence Berkeley National Laboratory. Users can examine specific building types and geographic areas, compare performance trends among similar buildings, identify and prioritize cost-saving energy efficiency improvements, and assess the range of likely savings from these improvements.
History
Prior to its launch, the BPD was described in a conference presentation by Elena Alschuler and Cody Taylor from October 2012. and another presentation by Alschuler in May 2013.
The BPD was launched in June 2013 with data from over 60,000 commercial and residential buildings.
A factsheet put out by the White House Press Room on May 28, 2014, cited the Building Performance Database as an example of a success story, saying that it has exceeded a milestone of 750,000 building records, making it the world's largest public database of real buildings’ energy performance information.
Data and API
The BPD has an application programming interface (API) that can return the energy use intensity for any group of buildings defined by an API request. The BPD contains business proprietary and confidential information, and all data is anonymized and can only be analyzed in aggregate. The API can be accessed using Python, Ruby, or cURL.
References
External links
Building energy rating
Energy conservation
Online databases |
https://en.wikipedia.org/wiki/T.H.%20Tse | T.H. Tse () is a Hong Kong academic who is a professor and researcher in program testing and debugging. He is ranked internationally as the second most prolific author in metamorphic testing.
According to Bruel et al., "Research on integrated formal and informal techniques can trace its roots to the work of T.H. Tse in the mid-eighties." The application areas of his research include object-oriented software, services computing, pervasive computing, concurrent systems, imaging software, and numerical programs. In addition, he creates graphic designs for non-government organizations.
Tse received the PhD from the London School of Economics in 1988 under the supervision of Frank Land and Ian Angell. He was a Visiting Fellow at the University of Oxford in 1990 and 1992. He is currently an honorary professor in computer science at The University of Hong Kong after retiring from his full professorship in 2014. He was decorated with an MBE by Queen Elizabeth II of the United Kingdom.
In 2013, an international event entitled "The Symposium on Engineering Test Harness" was held in Nanjing, China "in honor of the retirement of T.H. Tse". The acronym of the symposium was "TSE-TH".
In 2017 to 2020, Tse served as the intermediary for the fundraising of $140 million for The University of Hong Kong to establish the Tam Wing Fan Innovation Wings I and II in the Faculty of Engineering.
In 2019, Tse and team applied metamorphic testing to verify the robustness of citation indexing services, including Scopus and Web of Science. The innovative method, known as "metamorphic robustness testing", revealed that the presence of simple hyphens in the titles of scholarly papers adversely affects citation counts and journal impact factors, regardless of the quality of the publications. This "bizarre new finding", as well as the refutation by Web of Science and the clarification by Tse, was reported in ScienceAlert, Nature Index, Communications of the ACM, Psychology Today, and The Austral |
https://en.wikipedia.org/wiki/Coriell%20Institute%20for%20Medical%20Research | The Coriell Institute for Medical Research is an independent, non-profit biomedical research center dedicated to the study of the human genome. Coriell features programs in biobanking, personalized medicine, cell biology, cytogenetics, genotyping, and induced pluripotent stem cell science. Located in downtown Camden, New Jersey, the Institute has partnered with several prominent state and national health leaders, including Cooper University Hospital, the Cooper Medical School of Rowan University, the United States Air Force, the University of Pennsylvania, and Stanford University.
History
Coriell Institute was chartered in 1953 as the South Jersey Medical Research Foundation Laboratory and constructed facilities in 1956. The laboratory was later named for director Lewis L. Coriell, who had worked at the Camden Municipal Hospital and developed aseptic tissue culture techniques that ultimately allowed poliovirus to be grown in culture. Dr. Coriell also led the field trials for the resulting vaccine.
Operations
Biobanking
Regarded as one of the most diverse sources of cell lines and DNA available to the international research community, the Coriell Biorepositories maintain longstanding contracts with the National Institutes of Health and houses several significant collections, including the National Institute of General Medical Sciences Human Genetic Cell Repository, the National Institute of Neurological Disorders and Stroke Human Genetics DNA and Cell Line Repository, and the National Institute on Aging Cell Repository. The Institute houses cells for biotechnology companies and research foundations as well.
Research
In 2018, Coriell partnered with Cooper University Health Care and the Cooper Medical School of Rowan University to form the Camden Opioid Research Initiative (CORI), a state-funded research project studying risk factors for opioid use disorder. CORI utilizes a three-pronged approach: a study of chronic pain patients, a study of patients currently |
https://en.wikipedia.org/wiki/The%20Lacassane%20Company | The Lacassane Company is a land management company, with a goal of sustainable land management using an environmental management scheme that involves a host of tools including holistic management. Located primarily in Jefferson Davis and Cameron parish, with property in Ragley, Louisiana, the company headquarters is in Lake Charles, Louisiana.
History
Founded in 1929, by eight Lake Charles area businessmen, with land purchased from Jim Gardiner. The company was formed with 2250 common shares of stock with share-holders including, W. P. Weber, H. G. Chalkley, C. O. Noble, Henry Pomeroy, George M. King and Frank Roberts, M. J. Muller, and purchased 21,000 acres that included farm machinery, implements, stock, and cattle bought for $380,000.00, that included what was the Lowery and Illinois plantations, that became known as "The Illinois Plant", and "The Lowery Plant".
The Lacassane company continued with the previous form of tenant farming, increasing the original cattle herd, establishing trapping, hunting, oil and gas leases, and then the wetlands mitigation project. The Lacassine National Wildlife Refuge was established in 1937, when the company sold south of the Illinois Plant to the United States Government for $51,774.00.
Current
The Illinois Plant is called the Lacassane Coastal Prairie Mitigation Bank and the Ragley property, in conjunction with the "Calcasieu Mitigation Bank" and partnered with Ecosystem Investment Partners (EIP), is known as the Bill Jackson Longleaf Savannah Mitigation Bank. Both have been designated (through The Lacassane Company) by the Corps of Engineers as a mitigation bank providing ecosystem services to the public in the form of Environmental mitigation (compensatory mitigation) to ensure the no net loss wetlands policy is followed to prevent Biodiversity loss that keeps the greenhouse debt in check. The Lacassane Company partnered with The Coastal Plain Conservancy to hold conservation servitudes on the land. The banks are mon |
https://en.wikipedia.org/wiki/Eric%20Vanderburg | Eric Vanderburg is an American cyber security, storage networking and information technology professional and writer living in Cleveland, Ohio.
Vanderburg is Vice President of Cybersecurity at TCDI and an author and speaker on information security. He has been interviewed on TV and radio to discuss information security and he presents and conferences and seminars and has participated in panels on information security.
Education
Vanderburg attended Kent State University earning both a bachelor of Science in Technology and a Masters in Business Administration. He also has a Master of Business Administration (MBA), and pursued a doctorate in information assurance.
Life and career
Vanderburg has been interested in technology from an early age, often reading through computer manuals in his library, thus allowing himself to learn "some basics of programming". After spending some time with hackers and "Internet deviants" in the early 1990s, he managed to turn his interest in IT security into a career, and since the late 1990s his interest has primarily been that of cybersecurity within the business world. He has also spoken about the development of DevOps in the business world.
Vanderburg founded Independent Systems Consulting, an IT consulting firm, in 1997, which he ran for almost ten years. He then joined Jurinnov in 2006 where he directed IT, digital forensics, and cybersecurity consulting teams. In 2009, he built a network operations center at Jurinnov's headquarters to monitor data center operations and to perform transaction monitoring of key business and client systems. In 2016, Vanderburg became Vice President of Cybersecurity at TCDI when TCDI acquired Jurinnov. He is also a TechMin Network board member.
Vanderburg was involved with Hitachi Data Systems in testing their Essential NAS product which he compared to the Netapp FAS3000 NAS and he partnered with Lateral Data in using their Viewpoint eDiscovery tool to perform large-scale litigation document rev |
https://en.wikipedia.org/wiki/Geometric%20cryptography | Geometric cryptography is an area of cryptology where messages and ciphertexts are represented by geometric quantities such as angles or intervals and where computations are performed by ruler and compass constructions. The difficulty or impossibility of solving certain geometric problems like trisection of an angle using ruler and compass only is the basis for the various protocols in geometric cryptography. This field of study was suggested by Mike Burmester, Ronald L. Rivest and Adi Shamir in 1996. Though the cryptographic methods based on geometry have practically no real life applications, they are of use as pedagogic tools for the elucidation of other more complex cryptographic protocols. Geometric cryptography may have applications in the future once current mainstream encryption methods are made obsolete by quantum computing.
A geometric one-way function
Some of the geometric cryptographic methods are based on the impossibility of trisecting an angle using ruler and compass. Given an arbitrary angle, there is a straightforward ruler and compass construction for finding the triple of the given angle. But there is no ruler and compass construction for finding the angle which is exact one-third of an arbitrary angle. Hence the function which assigns the triple of an angle to a given angle can be thought of as a one-way function, the only constructions allowed being ruler and compass constructions.
A geometric identification protocol
A geometric identification protocol has been suggested based on the one-way function indicated above.
Assume that Alice wishes to establish a means of proving her identity later to Bob.
Initialization: Alice publishes a copy of an angle YA which is constructed by Alice as the triple of an angle XA she has constructed at random. Because trisecting an angle is impossible Alice is confident that she is the only one who knows XA.
Identification Protocol:
Alice gives Bob a copy of an angle R which she has constructed as the |
https://en.wikipedia.org/wiki/International%20Society%20for%20Developmental%20Psychobiology | International Society for Developmental Psychobiology (ISDP) promotes research on the behavioral development on all species including humans. It is an international-nonprofit organization. Its official scientific journal is Developmental Psychobiology published by John Wiley & Sons. It conducts annual meetings during which research on developmental psychobiology is presented and abstracts are published in Developmental Psychobiology.
References
External links
ISDP Official Website
Developmental Psychobiology, Official journal of ISDP
Health care-related professional associations based in the United States
Developmental biology
Psychology organizations based in the United States |
https://en.wikipedia.org/wiki/Network%20domain | A network domain is an administrative grouping of multiple private computer networks or local hosts within the same infrastructure. Domains can be identified using a domain name; domains which need to be accessible from the public Internet can be assigned a globally unique name within the Domain Name System (DNS).
A domain controller is a server that automates the logins, user groups, and architecture of a domain, rather than manually coding this information on each host in the domain. It is common practice, but not required, to have the domain controller act as a DNS server. That is, it would assign names to hosts in the network based on their IP addresses.
Example
Half of the staff of Building A uses Network 1, . This network has the VLAN identifier of VLAN 10. The other half of the staff of Building A uses Network 2, . This network has the VLAN identifier of VLAN 20. All of the staff of Building B uses Network 3, . This has the VLAN identifier of VLAN 11.
The router R1 serves as the gateway for all three networks, and the whole infrastructure is connected physically via ethernet. Network 2 and 3 are routed through R1 and have full access to each other.
Network 1 is completely separate from the other two, and does not have access to either of them. Network 2 and 3 are therefore in the same network domain, while Network 1 is in its own network domain, albeit alone.
A network administrator can then suitably name these network domains to match the infrastructure topology.
Usage
Use of the term network domain first appeared in 1965 and saw increasing usage beginning in 1985. It initially applied to the naming of radio stations based on broadcast frequency and geographic area. It entered its current usage by network theorists to describe solutions to the problems of subdividing a single homogeneous LAN and joining multiple networks, possibly constituted of different network architectures.
References
Computer networking
Domain Name System |
https://en.wikipedia.org/wiki/Predictive%20control%20of%20switching%20power%20converters | Predictive controllers rely on optimum control systems theory and aim to solve a cost function minimization problem. Predictive controllers are relatively easy to numerically implement but electronic power converters are non-linear time-varying dynamic systems, so a different approach to predictive must be taken.
Principles of non-linear predictive optimum control
The first step to designing a predictive controller is to derive a detailed direct dynamic model (including non-linearities) of the switching power converter. This model must contain enough detail of the converter dynamics to allow, from initial conditions, a forecast in real time and with negligible error, of the future behavior of the converter.
Sliding mode control of switching power converters chooses a vector to reach sliding mode as fast as possible (high switching frequency).
It would be better to choose a vector to ensure zero error at the end of the sampling period Δt.To find such a vector, a previous calculation can be made (prediction);
The converter has a finite number of vectors (states) and is usually non-linear: one way is to try all vectors to find the one that minimizes the control errors, prior to the application of that vector to the converter.
Direct dynamics model-based predictive control (DDMBPC)
Inverse dynamics optimum predictive control (IDOPC)
References
Power supplies
Power electronics
Electric power conversion |
https://en.wikipedia.org/wiki/Distributed%20Data%20Management%20Architecture | Distributed Data Management Architecture (DDM) is IBM's open, published software architecture for creating, managing and accessing data on a remote computer. DDM was initially designed to support record-oriented files; it was extended to support hierarchical directories, stream-oriented files, queues, and system command processing; it was further extended to be the base of IBM's Distributed Relational Database Architecture (DRDA); and finally, it was extended to support data description and conversion. Defined in the period from 1980 to 1993, DDM specifies necessary components, messages, and protocols, all based on the principles of object-orientation. DDM is not, in itself, a piece of software; the implementation of DDM takes the form of client and server products. As an open architecture, products can implement subsets of DDM architecture and products can extend DDM to meet additional requirements. Taken together, DDM products implement a distributed file system.
Distributed applications
The designers of distributed applications must determine the best placement of the application's programs and data in terms of the quantity and frequency of data to be transmitted, along with data management, security, and timeliness considerations. There are three client–server models for the design of distributed applications:
File Transfer Protocol (FTP) copies or moves whole files or database tables to each client so they can be operated on locally. This model is appropriate for highly interactive applications, such as document and spreadsheet editors, where each client has a copy of the corresponding editor and the sharing of such documents is generally not a concern.
Thin client applications present the interface of an application to users while the computational parts of the application are centralized with the affected files or databases. Communication then consists of remote procedure calls between the thin clients and a server in which uniquely designed message |
https://en.wikipedia.org/wiki/Historical%20dynamics | Historical dynamics broadly includes the scientific modeling of history. This might also be termed computer modeling of history, historical simulation, or simulation of history - allowing for an extensive range of techniques in simulation and estimation. Historical dynamics does not exist as a separate science, but there are individual efforts such as long range planning, population modeling, economic forecasting, demographics, global modeling, country modeling, regional planning, urban planning and many others in the general categories of computer modeling, planning, forecasting, and simulations.
Some examples of "large" history where historical dynamics simulations would be helpful include; global history, large structures, histories of empires, long duration history, philosophy of history, Eurasian history, comparative history, long-range environmental history, world systems theory, non-Western political and economic development, and historical demography.
Information sources for simulations
With the rise of technologies like wikis, and internet-wide search engines, some historical and social data can be mined to constrain models of history and society. Data from social media sites, and busy sites, can be mined for human patterns of action. These can provide more and more realistic behavioral models for individuals and groups of any size. Agent-based models and microsimulations of human behavior can be embedded in larger historical simulations. Related subfields are behavioral economics and human behavioral ecology.
Data mining, web mining, predictive analytics
Social media, web analytics, social networks
Automated translation, natural language processing, Turing test
Crowd computing has been applied to history, and offers another tool for historical verification and validation.
Sectoral databases
In every sector of human activity, there are extensive databases for transportation data, urban development, health statistics, education data, social data |
https://en.wikipedia.org/wiki/Zhao%20Youqin%27s%20%CF%80%20algorithm | Zhao Youqin's algorithm was an algorithm devised by Yuan dynasty Chinese astronomer and mathematician Zhao Youqin (, ? – 1330) to calculate the value of in his book Ge Xiang Xin Shu ().
Algorithm
Zhao Youqin started with an inscribed square in a circle with radius r.
If denotes the length of a side of the square, draw a perpendicular line d from the center of the circle to side l. Let e denotes r − d. Then from the diagram:
Extend the perpendicular line d to dissect the circle into an octagon; denotes the length of one side of octagon.
Let denotes the length of a side of hexadecagon
similarly
Proceeding in this way, he at last calculated the side of a 16384-gon, multiplying it by 16384 to obtain 3141.592 for a circle with diameter = 1000 units, or
He multiplied this number by 113 and obtained 355. From this he deduced that of the traditional values of , that is 3, 3.14, and , the last is the most exact.
See also
Liu Hui's algorithm
References
Chinese mathematics
Pi algorithms |
https://en.wikipedia.org/wiki/42%20%28school%29 | 42 is a private institution of higher education in computer science founded by Xavier Niel, Nicolas Sadirac (former executive director at Epitech), Kwame Yamgnane, and Florian Bucher (former executives at Epitech). The school opened in Paris in 2013. The school does not have any professors and is open 24/7. Students are trained through peer-to-peer pedagogy, and project-based learning.
42's name is a reference to the book The Hitchhiker's Guide to the Galaxy written by British author Douglas Adams: in the book, 42 is the Answer to the Ultimate Question of Life, the Universe, and Everything.
In addition to the official campus in Paris, France, the school model was adopted in Lyon, Reims, and Mulhouse, France, as well as in Spain, Romania, South Africa, Ukraine, Bulgaria, Moldova, Belgium, Russia, Morocco, the Netherlands, Indonesia, Finland, Germany, Adelaide, Australia, Armenia, the United Arab Emirates, London, Quebec, Canada, Bangkok, Florence, Rome, Lausanne Switzerland and Turkey.
History
Announced on March 26, 2013, 42 was opened in Paris on July 15, 2013, for the selection phase called La Piscine (the swimming-pool).
On May 17, 2016, 42 announced plans to open a second campus in Fremont, California. The Fremont campus was closed in 2020.
As of 2023, 47 campuses have been opened in 26 countries.
Endorsements
42 already had big supporters in tech like Snapchat CEO Evan Spiegel, Twitter and Square CEO Jack Dorsey, and Slack CEO Stewart Butterfield. Spiegel called it a school from the future, and Dorsey gave a glowing endorsement, saying "We are always looking for great engineers from any background and any education like 42."
Paul Graham founder of Y combinator stated on Twitter "My God is 42 impressive. This is not another programming bootcamp. It's another MIT."
Operation
The mode of operation of 42 was notably inspired by that of Epitech: selection using "swimming pool" sessions and teaching according to the project mode. 42 Network attempts to e |
https://en.wikipedia.org/wiki/Dashlane | Dashlane is a subscription-based password manager and digital wallet application available on macOS, Windows, iOS and Android. Dashlane uses a freemium pricing model with a subscription plan option.
Overview
Dashlane was founded on July 6, 2009, releasing their first software on May 23, 2012, that first included a password manager (encrypted using AES-256), which was walled behind a single master password. Over time, more features were introduced to the product such as:
Multi-factor authentication
Automatic form filling
Password generation
Digital wallet
Security breach alert
Virtual private network
Source code
The source code for the Android and the iOS app is available under the Creative Commons NonCommercial license 4.0.
See also
List of password managers
Cryptography
References
External links
Password managers
Cryptographic software
Nonfree unsigned Firefox WebExtensions
Internet Explorer add-ons
Google Chrome extensions
2012 software |
https://en.wikipedia.org/wiki/RCCA%20security | Replayable CCA security (RCCA security) is a security notion in cryptography that relaxes the older notion of Security against Chosen-Ciphertext Attack (CCA, more precisely adaptive security notion CCA2): all CCA-secure systems are RCCA secure but the converse is not true. The claim is that for a lot of use cases, CCA is too strong and RCCA suffices. Nowadays a certain amount of cryptographic scheme are proved RCCA-secure instead of CCA secure. It was introduced in 2003 in a research publication by Ran Canetti, Hugo Krawczyk and Jesper B. Nielsen.
References
Cryptography |
https://en.wikipedia.org/wiki/Hausdorff%20gap | In mathematics, a Hausdorff gap consists roughly of two collections of sequences of integers, such that there is no sequence lying between the two collections. The first example was found by . The existence of Hausdorff gaps shows that the partially ordered set of possible growth rates of sequences is not complete.
Definition
Let be the set of all sequences of non-negative integers, and define to mean .
If is a poset and and are cardinals, then a -pregap in is a set of elements for and a set of elements for such that:
The transfinite sequence is strictly increasing;
The transfinite sequence is strictly decreasing;
Every element of the sequence is less than every element of the sequence .
A pregap is called a gap if it satisfies the additional condition:
There is no element greater than all elements of and less than all elements of .
A Hausdorff gap is a -gap in such that for every countable ordinal and every natural number there are only a finite number of less than such that for all we have .
There are some variations of these definitions, with the ordered set replaced by a similar set. For example, one can redefine to mean for all but finitely many . Another variation introduced by is to replace by the set of all subsets of , with the order given by if has only finitely many elements not in but has infinitely many elements not in .
Existence
It is possible to prove in ZFC that there exist Hausdorff gaps and -gaps where is the cardinality of the smallest unbounded set in , and that there are no -gaps. The stronger open coloring axiom can rule out all types of gaps except Hausdorff gaps and those of type with .
References
External links
Descriptive set theory
Order theory
Integer sequences
General topology |
https://en.wikipedia.org/wiki/Nokia%20X%20platform | The Nokia X platform was a Linux-based mobile operating system and software platform originally developed by Nokia, and subsequently by Microsoft Mobile. Introduced on 24 February 2014, it was forked from Android and used on all the devices of the Nokia X family. It was also the next Nokia Linux project after the ill-fated MeeGo.
On 17 July 2014, after the acquisition of Nokia's devices unit, Microsoft announced that no more Nokia X smartphones will be introduced, marking the end of the Nokia X platform within only a few months after its introduction. The phones were succeeded by low-cost Lumia devices under the Microsoft Mobile brand name. Microsoft did not release an Android-based device under their own brand until 2020, in the form of the foldable Surface Duo.
Overview
The Nokia X software platform was based on the Android Open Source Project (AOSP) and the Linux kernel. Nokia combined Android apps with Nokia experiences (such as HERE Maps, Nokia Xpress and MixRadio) and Microsoft services (such as Skype and Outlook). Nokia officially described the software as bringing "the best of all worlds". It also encompasses features from the Asha platform, such as the Fastlane notification centre. The user interface mimics that of Windows Phone.
The OS has been compared to Amazon.com's Fire OS, which is also based on AOSP.
Applications
Google's applications were replaced by Nokia's and Microsoft's. When first released, the Google Play store was not included, with Nokia offering apps from their own Nokia Store. After the v2.1 update in September 2014 users were allowed to install Google Play and various other Google services through third party tools, but if users attempt to install Google services on their Nokia X devices it would usually be "bricked" and would require the Nokia Software Recovery Tool to restore the data.
As of February 2014, 75% of Android apps were compatible with the platform. Nokia noted that developers could port the remaining missing apps in a m |
https://en.wikipedia.org/wiki/RC%20coupling | RC coupling is the most widely used method of coupling in multistage amplifiers. It is an application of capacitive coupling. In this case the resistance R is the resistor connected at the collector terminal and the capacitor C is connected in between the amplifiers. It is also called a blocking capacitor, since it will block DC voltage. The main disadvantage of this coupling method is that it causes some loss for the low frequency signals. However, for amplifying signals of frequencies greater than 10 Hz, this coupling is the best and least expensive method. It is usually applied in small signal amplifiers, such as in record players, tape recorders, radio receivers, etc.
References
Audio amplifiers |
https://en.wikipedia.org/wiki/Cheetah%20Mobile | Cheetah Mobile Inc () is a Chinese mobile internet company headquartered in Beijing. , it has more than 634 million monthly active users.
History
Formation
Chen Rui (:zh:陳睿 current CEO of Bilibili) founded Cheetah Mobile. The company was established in 2010 as a merger of Kingsoft Security (Chen served as General Manager) and Conew Image, and grew to be the second-largest internet security software provider in China, according to iResearch. The company is located at 1st Yaojiayuan South Rd, Chaoyang District, Beijing, China.
Initial public offering
In 2014, Cheetah Mobile launched an IPO selling 13 million American depositary shares at US$14 per share, and thereby raised US$168 million. The IPO was managed by Morgan Stanley, JP Morgan Chase & Co., and Credit Suisse Group. Kingsoft and Tencent are major investors in Cheetah Mobile, holding 54% and 18% respectively.
Post IPO
In the late 2015, Cheetah Mobile announced that it had entered into a global strategic partnership with Yahoo. The company incorporated Yahoo's search and native advertising platforms within its own apps. As a result of this, Cheetah Mobile stated that its revenue generated from Yahoo increased by 30 percent daily within the first two weeks.
In February 2016, Cheetah Mobile and Cubot launched the CheetahPhone, an Android 6.0 Marshmallow based smartphone, at MWC in Barcelona, Spain.
Acquisition
On August 2, 2016, Cheetah Mobile announced its acquisition of a French startup News Republic for $57 million. News Republic is a news aggregator.
Ad fraud accusation
In March 2020, Cheetah Mobile was banned from Google Play due to their scheme of ad fraud, resulting in all of their games being removed as part of a 600 app deletion.
Insider trading charges
In September 2022, the U.S. Securities and Exchange Commission charged the company's CEO and former President with insider trading.
Products
Cheetah Mobile's ad supported products include:
Computer applications
Clean Master for PC – It cla |
https://en.wikipedia.org/wiki/AMD%20Eyefinity | AMD Eyefinity is a brand name for AMD video card products that support multi-monitor setups by integrating multiple (up to six) display controllers on one GPU. AMD Eyefinity was introduced with the Radeon HD 5000 Series "Evergreen" in September 2009 and has been available on APUs and professional-grade graphics cards branded AMD FirePro as well.
AMD Eyefinity supports a maximum of 2 non-DisplayPort displays (e.g., HDMI, DVI, VGA, DMS-59, VHDCI) (which AMD calls "legacy output") and up to 6 DisplayPort displays simultaneously using a single graphics card or APU. To feed more than two displays, the additional panels must have native DisplayPort support. Alternatively active DisplayPort-to-DVI/HDMI/VGA adapters can be employed.
The setup of large video walls by connecting multiple computers over Gigabit Ethernet or Ethernet is also supported.
The version of AMD Eyefinity (aka DCE, display controller engine) introduced with Excavator-based Carrizo APUs features a Video underlay pipe.
Overview
AMD Eyefinity is implemented by multiple on-die display controllers. The HD 5000-series designs host two internal clocks and one external clock. Displays connected over VGA, DVI, or HDMI each require their own internal clock. But all displays connected over DisplayPort can be driven from only one external clock. This external clock is what allows Eyefinity to fuel up to six monitors from a single card.
The entire HD 5000 series of products have Eyefinity capabilities supporting three outputs. The Radeon HD 5870 Eyefinity Edition, however, supports six mini DisplayPort outputs, all of which can be simultaneously active.
The display controller has two RAMDACs that drive the VGA or DVI ports in analog mode. For example, when a DVI-to-VGA converter is attached to a DVI port). It also has a maximum of six digital transmitters that can output either a DisplayPort signal or a TMDS signal for either DVI or HDMI, and two clock signal generators to drive the digital outputs in TMDS |
https://en.wikipedia.org/wiki/FAO%20GM%20Foods%20Platform | The FAO GM Foods Platform is a web platform where participating countries can share information on their assessments of the safety of genetically modified (recombinant-DNA) foods and feeds based on the Codex Alimentarius. It also allows for sharing of assessments of low-level GMO contamination (LLP, low-level presence).
The platform was set up by the Food and Agriculture Organization of the United Nations, and was launched at the FAO headquarters in Rome on 1 July 2013. The information uploaded to the platform is freely available to be read.
References
Agricultural organizations
Environmental organisations based in Italy
Food and Agriculture Organization
Food law
Food politics
Food safety
Food science
Information systems
International law |
https://en.wikipedia.org/wiki/Edmund%20Copeland | Edmund "Ed" J. Copeland () is a theoretical physicist, cosmologist, and professor of physics working in the Faculty of Science at the University of Nottingham, United Kingdom. Copeland won the 2013 Rayleigh Medal and Prize awarded by the Institute of Physics for his work on particle/string cosmology. He obtained his PhD from the University of Newcastle upon Tyne in 1985, with a thesis entitled "Quantum aspects of Kaluza-Klein cosmologies".
Copeland is well known for his appearances on the physics-popularizing YouTube channel Sixty Symbols, as well as the mathematics-popularizing channel Numberphile.
References
Academics of the University of Nottingham
British theoretical physicists
Mathematics popularizers
Science communicators
Living people
Year of birth missing (living people) |
https://en.wikipedia.org/wiki/WOEID | A WOEID (Where On Earth IDentifier) is a unique 32-bit reference identifier, originally defined by GeoPlanet and now assigned by Yahoo!, that identifies any feature on Earth. In 2009, Yahoo! released GeoPlanet's WOEID data to the public, with the last release on 1 June 2012, after which Yahoo! decided to cease making the data downloadable until they "determine a better way to surface the data as a part of the service".
WOEIDs are used by a number of other projects, including Flickr, OpenStreetMap, Twitter, WOEID Search Engine and Nations24.
WOEID of some popular locations on Earth
From WOEID Search Engine:
4118 - Toronto
44418 - London
615702 - Paris
2295019 - New Delhi
2295380 - Varanasi
2442047 - Los Angeles
2459115 - New York
2487956 - San Francisco
23424851 - Iran
29128560 - Kaithi
Example
E.g. Berlin does not know about Germany, which itself doesn't know about Europe and so forth. GeoPlanet records, or places as they are called by Yahoo!, always (except one) have a reference to its parent place and therefore offer relations between places like the following:
Parent (direct surrounding place)
Child (direct sub-places)
Siblings (places sharing the same parent and place type)
Ancestors (set of all parents)
If you take e.g. our company's district you will get the following family tree:
Deutschland (WOEID 23424829)
Bundesland Berlin (WOEID 2345496)
Stadtkreis Berlin (WOEID 1259838)
Berlin (WOEID 638242)
Ortsteil Pankow (WOEID 26821868)
Ortsteil Prenzlauer Berg (WOEID 26821872)
Ortsteil Wedding (WOEID 26821851)
Suan Luang (WOEID 12756344)
...
See also
Discrete Global Grid
List of geocoding systems
References
Geographic object identifiers
Geocodes |
https://en.wikipedia.org/wiki/Immunoediting | Immunoediting is a dynamic process that consists of immunosurveillance and tumor progression. It describes the relation between the tumor cells and the immune system. It is made up of three phases: elimination, equilibrium, and escape.
Definition
Immunoediting is characterized by changes in the immunogenicity of tumors due to the anti-tumor response of the immune system, resulting in the emergence of immune-resistant variants.
Phase 1: Elimination
The elimination phase, also known as immunosurveillance, includes innate and adaptive immune responses to tumour cells. For the innate immune response, several effector cells such as natural killer cells and T cells are activated by the inflammatory cytokines, which are released by the growing tumour cells, macrophages and stromal cells surrounding the tumour cells. The recruited tumour-infiltrating NK cells and macrophages produce interleukin 12 and interferon gamma, which kill tumour cells by cytotoxic mechanisms such as perforin, TNF-related apoptosis-inducing ligands (TRAILs), and reactive oxygen species. Most of the tumor cells are destroyed in this phase, but some of them survive and are able to reach equilibrium with the immune system.
The elimination phase consists of the following four phases:
The first phase involves the initiation of an antitumor immune response. Cells of the innate immune system recognize the presence of a growing tumor which has undergone stromal remodeling, causing local tissue damage. This is followed by the induction of inflammatory signals which is essential for recruiting cells of the innate immune system (e.g. natural killer cells, natural killer T cells, macrophages and dendritic cells) to the tumor site. During this phase, the infiltrating lymphocytes such as the natural killer cells and natural killer T cells are stimulated to produce IFN-gamma.
In the second phase, newly synthesized IFN-gamma induces tumor death (to a limited amount) as well as promoting the production of ch |
https://en.wikipedia.org/wiki/CodeHS | CodeHS is an interactive online learning platform offering computer science and programming instruction for schools and individual learners. CodeHS is focused on spreading access to and knowledge of computer science by offering online instructional materials supported by remote tutors. In the introductory learning module, students on the site practice computer science concepts and programming skills by giving commands to a dog named Karel. In the most popular course offered, which is similar to the original Karel programming language developed by Richard E. Pattis, Karel the dog must complete various tasks by moving around a grid world, and putting down and picking up tennis balls using only simple commands. Later learning modules teach more advanced concepts using languages like JavaScript, Java, and HTML.
History
CodeHS was founded in 2012 by Jeremy Keeshin and Zach Galant, both Stanford University Computer Science graduates. Keeshin and Galant based CodeHS on their experience as section leaders and teaching assistants for several of Stanford's introductory computer science courses. The company joined the Imagine K12 incubator's third class, launching in October 2012, and its investors include NewSchools Venture Fund, Seven Peaks Ventures, Kapor Capital, Learn Capital, Imagine K12, Marc Bell Ventures, and Lighter Capital. In total, CodeHS has raised $2.9 million as of December 2016.
NBC Education Nation
CodeHS was selected as one of three education technology companies to take part in the 2013 Innovation Challenge, part of the NBC Education Nation initiative. Innovation Nation challenge participants CodeHS, Teachley, and GigaBryte participated in a series of challenges in October 2013, culminating in a live pitch contest broadcast live on NBC during the Education Nation Summit. CodeHS won the Innovation Challenge, earning a $75,000 prize awarded by the Robin Hood Foundation.
Hour of Code
During the week of December 9, 2013, CodeHS participated in the nationwid |
https://en.wikipedia.org/wiki/Interstitial%20site | In crystallography, interstitial sites, holes or voids are the empty space that exists between the packing of atoms (spheres) in the crystal structure.
The holes are easy to see if you try to pack circles together; no matter how close you get them or how you arrange them, you will have empty space in between. The same is true in a unit cell; no matter how the atoms are arranged, there will be interstitial sites present between the atoms. These sites or holes can be filled with other atoms (interstitial defect). The picture with packed circles is only a 2D representation. In a crystal lattice, the atoms (spheres) would be packed in a 3D arrangement. This results in different shaped interstitial sites depending on the arrangement of the atoms in the lattice.
Close packed
A close packed unit cell, both face-centered cubic and hexagonal close packed, can form two different shaped holes. Looking at the three green spheres in the hexagonal packing illustration at the top of the page, they form a triangle-shaped hole. If an atom is arranged on top of this triangular hole it forms a tetrahedral interstitial hole. If the three atoms in the layer above are rotated and their triangular hole sits on top of this one, it forms an octahedral interstitial hole. In a close-packed structure there are 4 atoms per unit cell and it will have 4 octahedral voids (1:1 ratio) and 8 tetrahedral voids (1:2 ratio) per unit cell. The tetrahedral void is smaller in size and could fit an atom with a radius 0.225 times the size of the atoms making up the lattice. An octahedral void could fit an atom with a radius 0.441 times the size of the atoms making up the lattice. An atom that fills this empty space could be larger than this ideal radius ratio, which would lead to a distorted lattice due to pushing out the surrounding atoms, but it cannot be smaller than this ratio.
Face-centered cubic (FCC)
If half of the tetrahedral sites of the parent FCC lattice are filled by ions of opposit |
https://en.wikipedia.org/wiki/Euclides%20Danicus | Euclides Danicus (the Danish Euclid) is one of three books of mathematics written by Georg Mohr. It was published in 1672 simultaneously in Copenhagen and Amsterdam, in Danish and Dutch respectively. It contains the first proof of the Mohr–Mascheroni theorem, which states that every geometric construction that can be performed using a compass and straightedge can also be done with compass alone.
The book is divided into two parts. In the first part, Mohr shows how to perform all of the constructions of Euclid's Elements using a compass alone. In the second part, he includes some other specific constructions, including some related to the mathematics of the sundial.
Euclides Danicus languished in obscurity, possibly caused by its choice of language, until its rediscovery in 1928 in a bookshop in Copenhagen. Until then, the Mohr–Mascheroni theorem had been credited to Lorenzo Mascheroni, who published a proof in 1797, independently of Mohr's work. Soon after the rediscovery of Mohr's book, publications about it by Florian Cajori and Nathan Altshiller Court made its existence much more widely known. The Danish version was republished in facsimile in 1928 by the Royal Danish Academy of Sciences and Letters, with a foreword by Johannes Hjelmslev, and a German translation was published in 1929.
Only eight copies of the original publication of the book are known to survive. In 2005, one of these original copies was sold at auction, to Fry's Electronics, for what Gerald L. Alexanderson calls a "ridiculously low price": US$13,000.
References
Wikicommons has a copy of the original: https://commons.wikimedia.org/wiki/File:Georg_Mohr%27s_Euclides_Danicus.pdf
Further reading
.
1672 books
Danish non-fiction books
Dutch non-fiction books
Mathematics books |
https://en.wikipedia.org/wiki/Tixati | Tixati is a proprietary Linux and Windows BitTorrent client written in C++. It has standalone and portable versions with each new client version.
Features
In addition to standard BitTorrent client-sharing functions, Tixati provides integral chatrooms with channel chat as well as encrypted private messaging. Chatrooms can be either public or secret. Users are allowed to optionally share lists of magnet or URL links which are then searchable across all channels a user is joined to. Browsing a specific user's share list is also supported. The channels also allow for streaming audio and video media.
Fopnu
Since July 20, 2017, the developers of Tixati have released regular updates of a new P2P system (network and client) called Fopnu. It's visually similar to Tixati but Fopnu is not a torrent client. Fopnu is a decentralized network with the latest advances in P2P technology, pure UDP and with all communications being encrypted. The ad-free freeware client includes chat rooms, contacts list (with private messages), search windows, browsing of a contact's library and creation of contacts groups (to control access to your library). Sharing massive amounts of files is much easier (than creating a lot of Torrent files) and has very little overhead.
Reception
In 2012, TorrentFreak listed it among the top 10 μTorrent alternatives. The same year, it received a positive review from Ghacks. A 2014 review at BestVPN.com praised it for its lightweight design. In May 2015, Tixati was the fifth most popular torrent client by the audience of Lifehacker.
On January 6, 2017, the developer announced the release of version 2.52 for user alpha testing, which added an encrypted forum function to the channels. Posts to the forum may be visible to all users in the channel or may be private, between only 2 users. In March 2017, it was listed as a popular BitTorrent client by Tom's Guide. In December 2017, it received a positive review by TechRadar. In January 2018, it was reviewed posi |
https://en.wikipedia.org/wiki/Sony%20NEX-C3 | The Sony NEX-C3 is a digital camera announced 8 June 2011. It is a mirrorless interchangeable lens camera with a compact form factor and APS-C size image sensor. The Sony camera was manufactured in Black, Silver, and Pink. This camera was unfairly compared against later models such as the NEX-5R using a body only weight of 225g compared the NEX-5R battery and card inclusive weight of 276g, which lead to the mistaken claim that the NEX-C3 was 51g lighter. The camera was later replaced by the NEX-F3.
See also
Sony NEX-5
List of Sony E-mount cameras
List of smallest mirrorless cameras
References
NEX-C3
NEX-C3
Cameras introduced in 2011 |
https://en.wikipedia.org/wiki/Central%20polynomial | In algebra, a central polynomial for n-by-n matrices is a polynomial in non-commuting variables that is non-constant but yields a scalar matrix whenever it is evaluated at n-by-n matrices. That such polynomials exist for any square matrices was discovered in 1970 independently by Formanek and Razmyslov. The term "central" is because the evaluation of a central polynomial has the image lying in the center of the matrix ring over any commutative ring. The notion has an application to the theory of polynomial identity rings.
Example: is a central polynomial for 2-by-2-matrices. Indeed, by the Cayley–Hamilton theorem, one has that for any 2-by-2-matrices x and y.
See also
Generic matrix ring
References
Ring theory |
https://en.wikipedia.org/wiki/List%20of%20common%20EMC%20test%20standards | The following list outlines a number of electromagnetic compatibility (EMC) standards which are known at the time of writing to be either available or have been made available for public comment. These standards attempt to standardize product EMC performance, with respect to conducted or radiated radio interference from electrical or electronic equipment, imposition of other types of disturbance on the mains supply by such equipment, and the sensitivity of such equipment to received interference.
The legal status of these standards varies according to the jurisdiction. Standards called up by the European Union's EMC Directive effectively have the force of law in the EU.
IEC standards
The IEC standards on Electromagnetic compatibility (EMC) are mostly part of the IEC 61000 family. Below are some examples.
IEC/TR EN 61000-1-1, Electromagnetic compatibility (EMC) - Part 1: General - Section 1: Application and interpretation of fundamental definitions and terms
IEC/TR EN 61000-2-1, Electromagnetic compatibility (EMC) - Part 2: Environment - Section 1: Description of the environment - Electromagnetic environment for low-frequency conducted disturbances and signaling in public power supply systems
IEC/TR EN 61000-2-3, Electromagnetic compatibility (EMC) - Part 2: Environment - Section 3: Description of the environment - Radiated and non-network-frequency-related conducted phenomena
IEC EN 61000-3-2, Electromagnetic compatibility (EMC) - Part 3-2 - Limits - Limits for harmonic current emissions (equipment input current ≤ 16 A per phase)
IEC EN 61000-3-3, Electromagnetic compatibility (EMC) - Part 3-3 - Limits - Limitation of voltage changes, voltage fluctuations and flicker in public low-voltage supply systems, for equipment with rated current ≤ 16 A per phase and not subject to conditional connection
IEC EN 61000-3-4, Electromagnetic compatibility (EMC) - Part 3-4: Limits - Limitation of emission of harmonic currents in low-voltage power supply systems for equipment w |
https://en.wikipedia.org/wiki/Representation%20on%20coordinate%20rings | In mathematics, a representation on coordinate rings is a representation of a group on coordinate rings of affine varieties.
Let X be an affine algebraic variety over an algebraically closed field k of characteristic zero with the action of a reductive algebraic group G. G then acts on the coordinate ring of X as a left regular representation: . This is a representation of G on the coordinate ring of X.
The most basic case is when X is an affine space (that is, X is a finite-dimensional representation of G) and the coordinate ring is a polynomial ring. The most important case is when X is a symmetric variety; i.e., the quotient of G by a fixed-point subgroup of an involution.
Isotypic decomposition
Let be the sum of all G-submodules of that are isomorphic to the simple module ; it is called the -isotypic component of . Then there is a direct sum decomposition:
where the sum runs over all simple G-modules . The existence of the decomposition follows, for example, from the fact that the group algebra of G is semisimple since G is reductive.
X is called multiplicity-free (or spherical variety) if every irreducible representation of G appears at most one time in the coordinate ring; i.e., .
For example, is multiplicity-free as -module. More precisely, given a closed subgroup H of G, define
by setting and then extending by linearity. The functions in the image of are usually called matrix coefficients. Then there is a direct sum decomposition of -modules (N the normalizer of H)
,
which is an algebraic version of the Peter–Weyl theorem (and in fact the analytic version is an immediate consequence.) Proof: let W be a simple -submodules of . We can assume . Let be the linear functional of W such that . Then .
That is, the image of contains and the opposite inclusion holds since is equivariant.
Examples
Let be a B-eigenvector and X the closure of the orbit . It is an affine variety called the highest weight vector variety by Vinberg–Popov. It is multipli |
https://en.wikipedia.org/wiki/Broadcom%20Crystal%20HD | Crystal HD is Broadcom's hardware semiconductor intellectual property (SIP) core that performs video decoding.
Features
Crystal HD includes single chip high-definition advanced media processors BCM70012 (codenamed Link) and BCM70015 (codenamed Flea); these chips are available on mini PCIe cards.
The BCM970012 supports hardware decoding of H.264/MPEG-4 AVC, VC-1, WMV9 and MPEG-2 and the BCM970015 additionally supports DivX 3.11, 4.1, 5.X, 6.X and Xvid. VP8, VP9, Daala and HEVC are not supported.
Crystal HD is found in Intel Atom based machines, such as the Dell Inspiron Mini 10 HP Slate 500 or ExoPC, ASUS Eee Keyboard.
The commercial relevancy of dedicated video decoding accelerators was ended by the launch of the Intel Core i-series, featuring an integrated GPU with hardware video decoding (formerly only widespreadly available in discrete GPUs).
Operating system support
The Crystal HD SIP core must be supported by a device driver, which provides the video interfaces. One of these interfaces is then used by end-user software, for example Media Player Classic or GStreamer, to access CrystalHD.
Linux
Broadcom published a Linux device driver under GNU General Public License (GPL) version 2. Broadcom also published application and library source code on a royalty-free basis under the GNU Lesser General Public License (LGPL), version 2.1
Crystal HD can be accessed through the Video Acceleration API interface via an experimental driver (however, it cannot be recovered from the linked archive). A GStreamer plugin is available.
Crystal HD support is available in FFmpeg and MPlayer when compiled with the corresponding option.
It could be added to first generation Apple TV when OSMC is installed, although support was dropped in 2017.
Microsoft Windows
Broadcom published a device driver for Microsoft Windows that provides accelerated DirectShow renderers filters.
See also
Nvidia PureVideo
AMD Unified Video Decoder
Intel Quick Sync Video
Amlogic Video Engine
|
https://en.wikipedia.org/wiki/General%20Assembly%20%28school%29 | General Assembly is an American-headquartered private, for-profit education organization founded by CEO Jake Schwartz, Adam Pritzker, Matthew Brimer, and Brad Hargreaves in early 2011 and purchased by The Adecco Group in 2018. It maintains campuses in various countries throughout the world to teach entrepreneurs and business professionals practical technology skills. It provides courses in mobile and software engineering, data science, product management, and other digital technology–related courses.
History
General Assembly began in early 2011 as a co-working space in Midtown Manhattan, and evolved into a private school. It built its first campus in the Flatiron District with a grant from the New York City Economic Development Corporation. In 2015 the company raised $70 million in venture capital funding. , General Assembly has 15 campus locations on 4 continents.
In April 2018, human resources services company Adecco Group announced they were acquiring General Assembly for $413 million.
Course offerings
The school offers short courses, online classes (including overnight courses and free short online courses), and immersive 10- and 12- week courses in computer programming, data science, and product management, with an emphasis on web development and user experience design. Approximately 20% of its courses are offered through companies to their employees. In 2016 it worked with accounting firms to develop a framework for assessing student outcomes that it plans to market to other private educational institutions.
General Assembly is not accredited but has been approved by the California Bureau for Private Postsecondary Education.
Local General Assembly branches have provided discounted programs sponsored by the charity Get Well Cities for training the homeless. On Women's Equality Day in 2016 the company launched a hashtag campaign, #ilooklikeadeveloper, and scheduled events around the world focusing on women in computing.
References
External links
Gener |
https://en.wikipedia.org/wiki/Arrangement%20%28space%20partition%29 | In discrete geometry, an arrangement is the decomposition of the d-dimensional linear, affine, or projective space into connected cells of different dimensions, induced by a finite collection of geometric objects, which are usually of dimension one less than the dimension of the space, and often of the same type as each other, such as hyperplanes or spheres.
Definition
For a set of objects in , the cells in the arrangement
are the connected components of sets of the form
for subsets of . That is, for each the cells are the connected components of the points that belong to every object in and do not belong to any other object. For instance the cells of an arrangement of lines in the Euclidean plane are of three types:
Isolated points, for which is the subset of all lines that pass through the point.
Line segments or rays, for which is a singleton set of one line. The segment or ray is a connected component of the points that belong only to that line and not to any other line of
Convex polygons (possibly unbounded), for which is the empty set, and its intersection (the empty intersection) is the whole space. These polygons are the connected components of the subset of the plane formed by removing all the lines in .
Types of arrangement
Of particular interest are the arrangements of lines and arrangements of hyperplanes.
More generally, geometers have studied arrangements of other types of curves in the plane, and of other more complicated types of surface. Arrangements in complex vector spaces have also been studied; since complex lines do not partition the complex plane into multiple connected components, the combinatorics of vertices, edges, and cells does not apply to these types of space, but it is still of interest to study their symmetries and topological properties.
Applications
An interest in the study of arrangements was driven by advances in computational geometry, where the arrangements were unifying structures for many problems. Advances in st |
https://en.wikipedia.org/wiki/Deeplearning4j | Eclipse Deeplearning4j is a programming library written in Java for the Java virtual machine (JVM). It is a framework with wide support for deep learning algorithms. Deeplearning4j includes implementations of the restricted Boltzmann machine, deep belief net, deep autoencoder, stacked denoising autoencoder and recursive neural tensor network, word2vec, doc2vec, and GloVe. These algorithms all include distributed parallel versions that integrate with Apache Hadoop and Spark.
Deeplearning4j is open-source software released under Apache License 2.0, developed mainly by a machine learning group headquartered in San Francisco. It is supported commercially by the startup Skymind, which bundles DL4J, TensorFlow, Keras and other deep learning libraries in an enterprise distribution called the Skymind Intelligence Layer. Deeplearning4j was contributed to the Eclipse Foundation in October 2017.
Introduction
Deeplearning4j relies on the widely used programming language Java, though it is compatible with Clojure and includes a Scala application programming interface (API). It is powered by its own open-source numerical computing library, ND4J, and works with both central processing units (CPUs) and graphics processing units (GPUs).
Deeplearning4j has been used in several commercial and academic applications. The code is hosted on GitHub. A support forum is maintained on Gitter.
The framework is composable, meaning shallow neural nets such as restricted Boltzmann machines, convolutional nets, autoencoders, and recurrent nets can be added to one another to create deep nets of varying types. It also has extensive visualization tools, and a computation graph.
Distributed
Training with Deeplearning4j occurs in a cluster. Neural nets are trained in parallel via iterative reduce, which works on Hadoop-YARN and on Spark. Deeplearning4j also integrates with CUDA kernels to conduct pure GPU operations, and works with distributed GPUs.
Scientific computing for the JVM
Deeplearning4j |
https://en.wikipedia.org/wiki/Planarization | In the mathematical field of graph theory, planarization is a method of extending graph drawing methods from planar graphs to graphs that are not planar, by embedding the non-planar graphs within a larger planar graph.
Planarization may be performed by using any method to find a drawing (with crossings) for the given graph, and then replacing each crossing point by a new artificial vertex, causing each crossed edge to be subdivided into a path. The original graph will be represented as an immersion minor of its planarization.
In incremental planarization, the planarization process is split into two stages. First, a large planar subgraph is found within the given graph. Then, the remaining edges that are not already part of this subgraph are added back one at a time, and routed through an embedding of the planar subgraph. When one of these edges crosses an already-embedded edge, the two edges that cross are replaced by two-edge paths, with a new artificial vertex that represents the crossing point placed at the middle of both paths. In some case a third local optimization stage is added to the planarization process, in which edges with many crossings are removed and re-added in an attempt to improve the planarization.
Finding the largest planar subgraph
Using incremental planarization for graph drawing is most effective when the first step of the process finds as large a planar graph as possible. Unfortunately, finding the planar subgraph with the maximum possible number of edges (the maximum planar subgraph problem) is NP-hard, and MaxSNP-hard, implying that there probably does not exist a polynomial time algorithm that solves the problem exactly or that approximates it arbitrarily well.
In an n-vertex connected graph, the largest planar subgraph has at most 3n − 6 edges, and any spanning tree forms a planar subgraph with n − 1 edges. Thus, it is easy to approximate the maximum planar subgraph within an approximation ratio of one-third, simply by finding a spann |
https://en.wikipedia.org/wiki/FireChat | FireChat was a proprietary mobile app, developed by Open Garden, which used wireless mesh networking to enable smartphones to pass messages to each other peer-to-peer via Bluetooth, Wi-Fi, or Apple's Multipeer, without an internet connection.
Though it was not designed with the purpose in mind, FireChat was used as a communication tool in some civil protests.
FireChat is now discontinued. The official URL displays a 404 error page, and apps have not been updated since 2018.
History
The app was first introduced in March 2014 for iPhones, followed on April 3 by a version for Android devices.
In July 2015, FireChat introduced private messaging. Until then, it had only been possible to post messages to public chatrooms.
In May 2016, FireChat introduced FireChat Alerts, which allowed users to "push" alerts during a specific time and in a specific place. This feature was added for the benefit of aid workers doing disaster relief and stemmed from a partnership with the city of Marikina.
Usage
FireChat became popular in 2014 in Iraq following government restrictions on internet use, and thereafter during the 2014 Hong Kong protests. In 2015, FireChat was also promoted by protesters during the 2015 Ecuadorian protests. On September 11, 2015, during the pro-independence demonstration called Free Way to the Catalan Republic, FireChat was used 131,000 times. In January 2016, students protested at the University of Hyderabad, India, following the suicide of a PhD student named Rohith Vemula. Some students were reported to have used Firechat after the university shut down its Wi-Fi.
Security
In June 2014, Firechat's developers told Wired that "[p]eople need to understand that this is not a tool to communicate anything that would put them in a harmful situation if it were to be discovered by somebody who's hostile ... It was not meant for secure or private communications." By July 2015, the FireChat developers claimed to have added end-to-end encryption for its one-to-one p |
https://en.wikipedia.org/wiki/Least-squares%20adjustment | Least-squares adjustment is a model for the solution of an overdetermined system of equations based on the principle of least squares of observation residuals. It is used extensively in the disciplines of surveying, geodesy, and photogrammetry—the field of geomatics, collectively.
Formulation
There are three forms of least squares adjustment: parametric, conditional, and combined:
In parametric adjustment, one can find an observation equation relating observations explicitly in terms of parameters (leading to the A-model below).
In conditional adjustment, there exists a condition equation which is involving only observations (leading to the B-model below) — with no parameters at all.
Finally, in a combined adjustment, both parameters and observations are involved implicitly in a mixed-model equation .
Clearly, parametric and conditional adjustments correspond to the more general combined case when and , respectively. Yet the special cases warrant simpler solutions, as detailed below. Often in the literature, may be denoted .
Solution
The equalities above only hold for the estimated parameters and observations , thus . In contrast, measured observations and approximate parameters produce a nonzero misclosure:
One can proceed to Taylor series expansion of the equations, which results in the Jacobians or design matrices: the first one,
and the second one,
The linearized model then reads:
where are estimated parameter corrections to the a priori values, and are post-fit observation residuals.
In the parametric adjustment, the second design matrix is an identity, B=-I, and the misclosure vector can be interpreted as the pre-fit residuals, , so the system simplifies to:
which is in the form of ordinary least squares.
In the conditional adjustment, the first design matrix is null, .
For the more general cases, Lagrange multipliers are introduced to relate the two Jacobian matrices, and transform the constrained least squares problem into an uncon |
https://en.wikipedia.org/wiki/Synchronization%20of%20TV%20transmitter%20and%20receiver | In general, synchronizations is the process in which the signals are transmitted and received in accordance with the clock pulses. In synchronization of Television transmitter, a sharp pulse is sent between each video signal line so that to maintain the impeccable transmitter-receiver synchronization.
The receiver detects the video signal, synchronizing the transmitter and receiver is necessary to overcome the delay between different video packet arrivals.
The receiver must start scanning same line on the CRT output display or picture tube when the TV camera starts scanning that line, these are the horizontal lines that are being scanned.
The scanning speed of transmitter and receiver must be same so as to avoid signal distortion and deformation at the image in receiver output.
When horizontal lines are completely scanned, vertical flyback or retrace must occur simultaneously at both transmitter and receiver moving the electron beam from bottom line end to the start of the top line.
When the electron beam is returned to the left-hand side to start tracing a new line during the horizontal retrace, must occur inadvertently at both transmitter and receiver.
Cathode ray tube
Television transmitter
Vertical blanking interval
Terrestrial television
References
Television technology |
https://en.wikipedia.org/wiki/Philippine%20Diamond%20Tower | The Philippine Diamond Tower (PDT) was a proposed broadcast and observation tower to be built in the former Manila Seedling Bank property in QC CBD Triangle Park- North Triangle, Quezon City, Metro Manila, Philippines. The groundbreaking for the tower was initially scheduled to take place last October 12, 2014, in line with Quezon City's 75th foundation anniversary. Construction of the tower was planned to take place in mid 2015 and was planned to be completed in 2019.
The tower's height was planned to be at , to signify the country's Independence Day which is celebrated annually on June 12. It is set to be completed in 3 years and will be open to the public by 2017 - 2018. Philippine Diamond Tower is planned to be a major landmark not only of Manila, but the entire Philippines. A city ordinance was planned to be enacted to support the development of the tower.
In February 2016, the Japanese government was reportedly interested to invest in the project through The Corporation for the Overseas Development of Japan's ICT and Postal Services with a local subsidiary. China was also reportedly interested in the project and was likely to bid. The tower was expected to cost around and was projected to be completed by 2019.
However, construction of PDT was cancelled due to unknown reasons when it was shelved out. Construction never commenced like the proposed Centennial Tower and the Pagcor Tower despite the introduction of Digital Terrestrial Television and ISDB-T.
See also
Pagcor Tower
References
Unbuilt buildings and structures in the Philippines
Observation towers in the Philippines
Buildings and structures in Quezon City
Radio masts and towers |
https://en.wikipedia.org/wiki/Open%20coloring%20axiom | The open coloring axiom (abbreviated OCA) is an axiom about coloring edges of a graph whose vertices are a subset of the real numbers: two different versions were introduced by and by .
Statement
Suppose that X is a subset of the reals, and each pair of elements of X is colored either black or white, with the set of white pairs being open in the complete graph on X. The open coloring axiom states that either:
X has an uncountable subset such that any pair from this subset is white; or
X can be partitioned into a countable number of subsets such that any pair from the same subset is black.
A weaker version, OCAP, replaces the uncountability condition in the first case with being a compact perfect set in X. Both OCA and OCAP can be stated equivalently for arbitrary separable spaces.
Relation to other axioms
OCAP can be proved in ZFC for analytic subsets of a Polish space, and from the axiom of determinacy. The full OCA is consistent with (but independent of) ZFC, and follows from the proper forcing axiom.
OCA implies that the smallest unbounded set of Baire space has cardinality . Moreover, assuming OCA, Baire space contains few "gaps" between sets of sequences — more specifically, that the only possible gaps are Hausdorff gaps and analogous (κ,ω)-gaps where κ is an initial ordinal not less than ω2.
References
Axioms of set theory
Real analysis
Graph coloring
Infinite graphs
Independence results
Determinacy |
https://en.wikipedia.org/wiki/Elliptic%20algebra | In algebra, an elliptic algebra is a certain regular algebra of a Gelfand–Kirillov dimension three (quantum polynomial ring in three variables) that corresponds to a cubic divisor in the projective space P2. If the cubic divisor happens to be an elliptic curve, then the algebra is called a Sklyanin algebra. The notion is studied in the context of noncommutative projective geometry.
References
Algebraic structures
Algebraic logic |
https://en.wikipedia.org/wiki/Weil%E2%80%93Brezin%20Map | In mathematics, the Weil–Brezin map, named after André Weil and Jonathan Brezin, is a unitary transformation that maps a Schwartz function on the real line to a smooth function on the Heisenberg manifold. The Weil–Brezin map gives a geometric interpretation of the Fourier transform, the Plancherel theorem and the Poisson summation formula. The image of Gaussian functions under the Weil–Brezin map are nil-theta functions, which are related to theta functions. The Weil–Brezin map is sometimes referred to as the Zak transform, which is widely applied in the field of physics and signal processing; however, the Weil–Brezin Map is defined via Heisenberg group geometrically, whereas there is no direct geometric or group theoretic interpretation from the Zak transform.
Heisenberg manifold
The (continuous) Heisenberg group is the 3-dimensional Lie group that can be represented by triples of real numbers with multiplication rule
The discrete Heisenberg group is the discrete subgroup of whose elements are represented by the triples of integers. Considering acts on on the left, the quotient manifold is called the Heisenberg manifold.
The Heisenberg group acts on the Heisenberg manifold on the right. The Haar measure on the Heisenberg group induces a right-translation-invariant measure on the Heisenberg manifold. The space of complex-valued square-integrable functions on the Heisenberg manifold has a right-translation-invariant orthogonal decomposition:
where
.
Definition
The Weil–Brezin map is the unitary transformation given by
for every Schwartz function , where convergence is pointwise.
The inverse of the Weil–Brezin map is given by
for every smooth function on the Heisenberg manifold that is in .
Fundamental unitary representation of the Heisenberg group
For each real number , the fundamental unitary representation of the Heisenberg group is an irreducible unitary representation of on defined by
.
By Stone–von Neumann theorem, this is the unique |
https://en.wikipedia.org/wiki/100%20prisoners%20problem | The 100 prisoners problem is a mathematical problem in probability theory and combinatorics. In this problem, 100 numbered prisoners must find their own numbers in one of 100 drawers in order to survive. The rules state that each prisoner may open only 50 drawers and cannot communicate with other prisoners. At first glance, the situation appears hopeless, but a clever strategy offers the prisoners a realistic chance of survival.
Danish computer scientist Peter Bro Miltersen first proposed the problem in 2003.
Problem
The 100 prisoners problem has different renditions in the literature. The following version is by Philippe Flajolet and Robert Sedgewick:
The director of a prison offers 100 death row prisoners, who are numbered from 1 to 100, a last chance. A room contains a cupboard with 100 drawers. The director randomly puts one prisoner's number in each closed drawer. The prisoners enter the room, one after another. Each prisoner may open and look into 50 drawers in any order. The drawers are closed again afterwards. If, during this search, every prisoner finds their number in one of the drawers, all prisoners are pardoned. If even one prisoner does not find their number, all prisoners die. Before the first prisoner enters the room, the prisoners may discuss strategy — but may not communicate once the first prisoner enters to look in the drawers. What is the prisoners' best strategy?
If every prisoner selects 50 drawers at random, the probability that a single prisoner finds their number is 50%. Therefore, the probability that all prisoners find their numbers is the product of the single probabilities, which is ()100 ≈ , a vanishingly small number. The situation appears hopeless.
Solution
Strategy
Surprisingly, there is a strategy that provides a survival probability of more than 30%. The key to success is that the prisoners do not have to decide beforehand which drawers to open. Each prisoner can use the information gained from the contents of every draw |
https://en.wikipedia.org/wiki/Bioluminescent%20bacteria | Bioluminescent bacteria are light-producing bacteria that are predominantly present in sea water, marine sediments, the surface of decomposing fish and in the gut of marine animals. While not as common, bacterial bioluminescence is also found in terrestrial and freshwater bacteria. These bacteria may be free living (such as Vibrio harveyi) or in symbiosis with animals such as the Hawaiian Bobtail squid (Aliivibrio fischeri) or terrestrial nematodes (Photorhabdus luminescens). The host organisms provide these bacteria a safe home and sufficient nutrition. In exchange, the hosts use the light produced by the bacteria for camouflage, prey and/or mate attraction. Bioluminescent bacteria have evolved symbiotic relationships with other organisms in which both participants benefit close to equally. Another possible reason bacteria use luminescence reaction is for quorum sensing, an ability to regulate gene expression in response to bacterial cell density.
History
Records of bioluminescence due to bacteria have existed for thousands of years. They appear in the folklore of many regions, including Scandinavia and the Indian subcontinent. Both Aristotle and Charles Darwin have described the phenomenon of the oceans glowing. Since its discovery less than 30 years ago, the enzyme luciferase and its regulatory gene, lux, have led to major advances in molecular biology, through use as a reporter gene. Luciferase was first purified by McElroy and Green in 1955. It was later discovered that there were two subunits to luciferase, called subunits α and β. The genes encoding these enzymes, luxA and luxB, respectively, were first isolated in the lux operon of Aliivibrio fisheri.
Purpose of bio-luminescence
The wide-ranged biological purposes of bio-luminescence include but are not limited to attraction of mates, defense against predators, and warning signals. In the case of bioluminescent bacteria, bio-luminescence mainly serves as a form of dispersal. It has been hypothesized that |
https://en.wikipedia.org/wiki/Cyber%20Essentials | Cyber Essentials is a United Kingdom certification scheme designed to show an organisation has a minimum level of protection in cyber security through annual assessments to maintain certification.
Backed by the UK government and overseen by the National Cyber Security Centre (NCSC). It encourages organisations to adopt good practices in information security. Cyber Essentials also includes an assurance framework and a simple set of security controls to protect information from threats coming from the internet.
The certification underwent substantial changes in January 2022 which included bringing all cloud services into scope and changes to the requirements on multi-factor authentication, passwords and pins.
Certification
The Cyber Essentials program provides two levels, the first is self-certification and the second requires independent validation of claims made:
Cyber Essentials
Commonly referred to as mark your own homework, organisations self-assess their systems, and then complete an online assessment. The online assessment is marked by a Cyber Essentials Assessor who provides feedback on any areas where improvements could be made.
There is no independent validation of the accuracy of the answers at this level.
The cost for Cyber Essentials starts from £300 and is subject to VAT in the UK. The pricing model is tiered based on the number of employees and more information can be found on the IASME website.
Cyber Essentials Plus
The same as the basic but with independent validation by an accredited third party.
Systems are independently tested, and Cyber Essentials is integrated into the organisation's information risk management.
The cost for the Plus accreditation is dependent on the complexity of the environment but for a simple SME would typically cost around £1,400 and subject to VAT within the UK.
IASME has incorporated the Cyber Essentials into the wider IASME information assurance standard.
As with ISO/IEC 27001, organisations may choose to li |
https://en.wikipedia.org/wiki/Proton%20Mail | Proton Mail (previously written as ProtonMail) is a Swiss end-to-end encrypted email service founded in 2013 headquartered in Plan-les-Ouates, Switzerland. It uses client-side encryption to protect email content and user data before they are sent to Proton Mail servers, unlike other common email providers such as Gmail and Outlook.com. The service can be accessed through a webmail client, the Tor network, or dedicated iOS and Android apps.
Proton Mail is run by Proton AG (formerly Proton Technologies), which is based in Plan-les-Ouates, Switzerland. The company also operates Proton VPN, Proton Drive and Proton Calendar. Proton Mail received initial funding through a crowdfunding campaign. Although the default account setup is free, the service is sustained by optional paid services. Initial membership was by invitation only; however, beginning in March 2016, Proton Mail was opened to the public. Acquiring more than 2 million users by 2017, membership grew to almost 70 million by 2022.
History
On May 16, 2014, Proton Mail entered into public beta. It was met with enough response that after three days they needed to temporarily suspend beta signups to expand server capacity. Two months later, Proton Mail received from 10,576 donors through a crowdfunding campaign on Indiegogo, while aiming for . During the campaign, PayPal froze Proton Mail's PayPal account, thereby preventing the withdrawal of worth of donations. PayPal stated that the account was frozen due to doubts of the legality of encryption, statements that opponents said were unfounded. The restrictions were lifted the following day.
On March 18, 2015, Proton Mail received from the non-profit Fondation Genevoise pour l'Innovation Technologique (FONGIT) and Charles River Ventures, although by 2022, the company no longer had venture capital investors. On 14 August 2015, Proton Mail released major version 2.0, which included a rewritten codebase for its web interface. On 17 March 2016, Proton Mail release |
https://en.wikipedia.org/wiki/Flexible%20battery | Flexible batteries are batteries, both primary and secondary, that are designed to be conformal and flexible, unlike traditional rigid ones. They can maintain their characteristic shape even against continual bending or twisting. The increasing interest in portable and flexible electronics has led to the development of flexible batteries which can be implemented in products such as smart cards, wearable electronics, novelty packaging, flexible displays and transdermal drug delivery patches. The advantages of flexible batteries are their conformability, light weight, and portability, which makes them easy to be implemented in products such as flexible and wearable electronics. Hence efforts are underway to make different flexible power sources including primary and rechargeable batteries with high energy density and good flexibility.
Basic methods and designs
In general, a battery is made of one or several galvanic cells, where each cell consists of cathode, anode, separator, and in many cases current collectors. In flexible batteries all these components need to be flexible. These batteries can be fabricated into different shapes and sizes and by different methods. One approach is to use polymer binders to fabricate composite electrodes where conductive additives are used to enhance their conductivity. The electrode materials can be printed or coated onto flexible substrates. The cells are assembled into flexible packaging materials to maintain bendability. Others approaches include the filtering of electrode suspension through filters to form free-standing films, or use flexible matrix to hold electrode materials. There are also other designs like cable batteries.
Flexible secondary (rechargeable) batteries
There have been many efforts in adapting conventional batteries such as zinc-carbon and lithium ion, and at the same time new materials such as those based on nanoparticle complexes are being developed for flexible battery and supercapacitor electrodes. For |
https://en.wikipedia.org/wiki/Thermal%20tails | Thermal tails are an effect found in amplifiers, typically in op-amps, emitter-followers, and differential pairs. The effect is to cause a slow drift from ideal of the output of the amplifier from ideal over time. The cause is the mismatch of temperature of the different transistors on the substrate. Differential pairs have poor recovery from temperature mismatch.
The extent of the problem can be determined from the thermal conductivity of the substrate. The lower it is, the more of an issue this will be. It can also be caused by a non-shallow trench isolation.
When the power dissipation of a BJT changes the temperature changes. This causes a change in Vbe, thus affecting the output.
Thermal tails generally start on the output transistor as it is the one delivering the most power.
A thermal tail can be quantified by either loading the output stage of the amplifier or by conducting an AC frequency plot and looking for a rolloff not found due to parasitical components.
References
http://www.analog.com/library/analogdialogue/archives/29-2/qanda.html
Electronic amplifiers |
https://en.wikipedia.org/wiki/Clinical%20geropsychology | Clinical geropsychology is the application by psychologists in a range of sub-disciplines (clinical psychology, counseling psychology) of "the knowledge and methods of psychology to understanding and helping older persons and their families to maintain well-being, overcome problems and achieve maximum potential during later life".
Background and definition
The population of the world is aging at a rapid rate. Globally, those aged 60 years or over numbered 962 million in 2017, more than twice as large as the number of older persons in 1980. The number of older persons is expected to double again by 2050, when it is projected to reach nearly 2.1 billion persons. Globally, the number of persons aged 80 years or over is projected to increase more than threefold between 2017 and 2050, rising from 137 million to 425 million. For the first time in human history, the world has more individuals age 65 and older than those age 5 years old and under.
The Administration on Aging reports that people age 65 and older constituted about 15.6% of the US population in 2017, and these numbers are expected to grow exponentially. From 2007-2017, the population age 65 and over saw a 34% increase, compared with a 4% increase for the under-65 population. By 2040, there will be an estimated 80.8 million older adults in the US, constituting approximately 21.6% of the population.
According to the World Health Organization, over 20% of adults aged 60 and over have a mental or neurological disorder (excluding headache disorders), and 6.6% of all disability (disability adjusted life years-DALYs) among people over 60 years is attributed to mental and neurological disorders. In addition, older adults often experience a multitude of changes in later life, including declines in health, loss of loved ones, work transitions, changes in residence, and loss of independence, and the approach of their mortality.
Given the expected growth of the older adult population, many psychologists will end up |
https://en.wikipedia.org/wiki/Geometric%20transformation | In mathematics, a geometric transformation is any bijection of a set to itself (or to another such set) with some salient geometrical underpinning. More specifically, it is a function whose domain and range are sets of points — most often both or both — such that the function is bijective so that its inverse exists. The study of geometry may be approached by the study of these transformations.
Classifications
Geometric transformations can be classified by the dimension of their operand sets (thus distinguishing between, say, planar transformations and spatial transformations). They can also be classified according to the properties they preserve:
Displacements preserve distances and oriented angles (e.g., translations);
Isometries preserve angles and distances (e.g., Euclidean transformations);
Similarities preserve angles and ratios between distances (e.g., resizing);
Affine transformations preserve parallelism (e.g., scaling, shear);
Projective transformations preserve collinearity;
Each of these classes contains the previous one.
Möbius transformations using complex coordinates on the plane (as well as circle inversion) preserve the set of all lines and circles, but may interchange lines and circles.
Conformal transformations preserve angles, and are, in the first order, similarities.
Equiareal transformations, preserve areas in the planar case or volumes in the three dimensional case. and are, in the first order, affine transformations of determinant 1.
Homeomorphisms (bicontinuous transformations) preserve the neighborhoods of points.
Diffeomorphisms (bidifferentiable transformations) are the transformations that are affine in the first order; they contain the preceding ones as special cases, and can be further refined.
Transformations of the same type form groups that may be sub-groups of other transformation groups.
Opposite group actions
Many geometric transformations are expressed with linear algebra. The bijective linear transformations ar |
https://en.wikipedia.org/wiki/Dualex | The Dualex is an optical sensor developed by Force-A (No longer in business) for the assessment of flavonol, anthocyanin, and chlorophyll contents in leaves. The sensor is a result of technology transfer from the CNRS (National Center for Scientific Research) and University of Paris-Sud Orsay. It allows to perform real-time and non-destructive measurements. The main applications are plant science and agriculture research.
Calculated indices
The assessment of polyphenolic compounds in leaves is based on the absorbance of the leaf epidermis through the screening effect it procures to chlorophyll fluorescence.
The indices calculated by Dualex are:
Anth, for the anthocyanin index
Chl, for the chlorophyll index
Flav, for the flavonols index
NBI, for the nitrogen balance index
Applications
Based on the four measured indices, this optical sensor is applied in the fields of research as follows:
Plant physiology
Genetic studies
Plant phenology
Herbal selection
It is equally applied in studies related to chlorophyll (nutritional chlorosis, potential photosynthesis), flavonols (UV protection, leaf light environment) and anthocyanins (temperature stress, light selection).
References
Optical devices
Sensors |
https://en.wikipedia.org/wiki/Random%20algebra | In set theory, the random algebra or random real algebra is the Boolean algebra of Borel sets of the unit interval modulo the ideal of measure zero sets. It is used in random forcing to add random reals to a model of set theory. The random algebra was studied by John von Neumann in 1935 (in work later published as ) who showed that it is not isomorphic to the Cantor algebra of Borel sets modulo meager sets. Random forcing was introduced by .
See also
Random number
References
Boolean algebra
Forcing (mathematics) |
https://en.wikipedia.org/wiki/Institute%20of%20Refrigeration | The Institute of Refrigeration is an organisation in the UK that supports the refrigeration and air-conditioning industry.
History
The Institute was formed in 1899 as the Cold Storage and Ice Association, the first national society in the world for the refrigeration industry. The Institute's first president was Alan Egerton, 3rd Baron Egerton. It became the IOR in 1944 when professional membership was introduced. In 2010 the Institute launched a short video explaining the opportunities for careers in the refrigeration industry under the title Careers in Cooling. This uses interviews with a wide range of young people working in different aspects of refrigeration and air-conditioning to explain what a rewarding career it can be. A webpage was also set up to support the video.
Structure
The Institute of Refrigeration is governed by a board of trustees which comprises the President, the President-Elect, the Immediate Past-President, the Honorary Treasurer and six elected members.
The current council comprises
President - Graeme Fox, FInstR
Immediate Past-President - Mike Creamer, FInstR
President Elect -
Hon Treasurer - Nick Rivers, FInstR
Elected Members - Lisa-Jayne Cook, MInstR, Juliet Loiselle, MInstR, John Skelton, FInstR, John Ellis, FInstR, Catarina Marques, MInstR, Ian Fisher, FInstR
The work of the Institute is carried out by committees, including
Membership Committee - chair Dr Rob Lamb
Technical Committee - chair David Paget
Papers and Publications Committee - chair Colin Vines
International Refrigeration Committee - chair Dr Andy Pearson
Service Engineers Section - chair David Sowden
Sustainable Innovation in Refrigeration and Air Conditioning - chair Prof Graeme Maidment
Annual Dinner Steering Committee - chair Paul Arrowsmith
Education Committee - chair John Skelton
Women in RACHP Network - Chair Samantha Buckell
Branches
It has branches covering:
East Anglia
Northern
Scotland
and co-operates with independent refrigeration soci |
https://en.wikipedia.org/wiki/Rotameter%20%28railway%29 | The New South Wales Government Railways constructed in 1903 a device for measuring the length of its lines of railway. That authority named the machine a Rotameter. It consisted of a four-wheel trolley with an additional large fifth wheel which traveled along the running surface of the rail. Its last recorded use was in the 1920s.
References
Railway buildings and structures
Measuring instruments |
https://en.wikipedia.org/wiki/Cheyette%20model | In mathematical finance, the Cheyette Model is a quasi-Gaussian, quadratic volatility model of interest rates intended to overcome certain limitations of the Heath-Jarrow-Morton framework.
By imposing a special time dependent structure on the forward rate volatility function, the Cheyette approach allows for dynamics which are Markovian, in contrast to the general HJM model.
This in turn allows the application of standard econometric valuation concepts.
External links and references
Cheyette, O. (1994). Markov representation of the Heath-Jarrow-Morton model (working paper). Berkeley: BARRA Inc.
Chibane, M. and Law, D. (2013). A quadratic volatility Cheyette model, Risk.net
Financial models
Mathematical finance
Fixed income analysis
Heath–Jarrow–Morton framework |
https://en.wikipedia.org/wiki/Z-source%20inverter | A Z-source inverter is a type of power inverter, a circuit that converts direct current to alternating current. The circuit functions as a buck-boost inverter without making use of DC-DC converter bridge due to its topology.
Impedance (Z) source networks efficiently convert power between source and load from DC to DC, DC to AC, and from AC to AC.
The numbers of modifications and new Z-source topologies have grown rapidly since 2002. Improvements to the impedance networks by introducing coupled magnetics have also been lately proposed for achieving even higher voltage boosting, while using a shorter shoot-through time. They include the Γ-source, T-source, trans-Z-source, TZ-source, LCCT-Z-source that utilizes a high-frequency transformer connected in series with two DC-current-blocking capacitors, high-frequency transformer-isolated, and Y-source networks. Amongst them, the Y-source network is more versatile and can be viewed as the generic network, from which the Γ-source, T-source, and trans-Z-source networks are derived. The incommensurate properties of this network open a new horizon to researchers and engineers to explore, expand, and modify the circuit for a wide range of power conversion applications.
Types of inverters
Inverters can be classified by their structure as
Single-phase inverter: This type of inverter consists of two legs or two poles. (A pole is connection of two switches where source of one and drain of other are connected and this common point is taken out).
Three-phase inverter: This type of inverter consists of three legs or poles or four legs (three legs for phases and one for neutral).
Inverters are also classified based on the type of input source as follows:
Voltage-source inverter (VSI): In this type of inverter, a constant voltage source acts as input to the inverter bridge. The constant voltage source is obtained by connecting a large capacitor across the DC source.
Current-source inverter (CSI): In this type of inverter, a co |
https://en.wikipedia.org/wiki/Cloud%20computing%20issues | Cloud computing has become a social phenomenon used by most people every day. As with every important social phenomenon there are issues that limit its widespread adoption. In the present scenario, cloud computing is seen as a fast developing area that can instantly supply extensible services by using internet with the help of hardware and software virtualization. The biggest advantage of cloud computing is flexible lease and release of resources as per the requirement of the user. Other benefits encompass betterment in efficiency, compensating the costs in operations and management. It curtails down the high prices of hardware and software
Although, there are numerous benefits of adopting the latest cloud technology still there are privacy issues involved in cloud computing because in the cloud at any time the data can outbreak the service provider and the information is deleted purposely. There are security issues of various kinds related to cloud computing falling into two broader categories: First, the issues related to the cloud security that the cloud providers face (like software provided to the organizations, infrastructure as a service). Secondly, the issues related to the cloud security that the customers experience (organizations who store data on the cloud)
Most issues start from the fact that the user loses control of their data, because it is stored on a computer belonging to someone else (the cloud provider). This happens when the owner of the remote servers is a person or organization other than the user; as their interests may point in different directions (for example, the user may wish that their information is kept private, but the owner of the remote servers may want to take advantage of it for their own business). Other issues hampering the adoption of cloud technologies include the uncertainties related to guaranteed QoS provisioning, automated management, and remediation in cloud systems.
Many issues relate to cloud computing, some of whic |
https://en.wikipedia.org/wiki/Cloud%20management | Cloud management is the management of cloud computing products and services.
Public clouds are managed by public cloud service providers, which include the public cloud environment’s servers, storage, networking and data center operations. Users may also opt to manage their public cloud services with a third-party cloud management tool.
Users of public cloud services can generally select from three basic cloud provisioning categories:
User self-provisioning: Customers purchase cloud services directly from the provider, typically through a web form or console interface. The customer pays on a per-transaction basis.
Advanced provisioning: Customers contract in advance a predetermined amount of resources, which are prepared in advance of service. The customer pays a flat fee or a monthly fee.
Dynamic provisioning: The provider allocates resources when the customer needs them, then decommissions them when they are no longer needed. The customer is charged on a pay-per-use basis.
Managing a private cloud requires software tools to help create a virtualized pool of compute resources, provide a self-service portal for end users and handle security, resource allocation, tracking and billing. Management tools for private clouds tend to be service driven, as opposed to resource driven, because cloud environments are typically highly virtualized and organized in terms of portable workloads.
In hybrid cloud environments, compute, network and storage resources must be managed across multiple domains, so a good management strategy should start by defining what needs to be managed, and where and how to do it. Policies to help govern these domains should include configuration and installation of images, access control, and budgeting and reporting. Access control often includes the use of Single sign-on (SSO), in which a user logs in once and gains access to all systems without being prompted to log in again at each of them.
Characteristics of Cloud Management
Cloud ma |
https://en.wikipedia.org/wiki/Multicloud | Multicloud (also written as multi-cloud or multi cloud) refers to a company utilizing multiple cloud computing services from various public vendors within a single, heterogeneous architecture. This approach enhances cloud infrastructure capabilities and optimizes costs. It also refers to the distribution of cloud assets, software, applications, etc. across several cloud-hosting environments. With a typical multicloud architecture utilizing two or more public clouds as well as multiple private clouds, a multicloud environment aims to eliminate the reliance on any single cloud provider and thereby alleviate vendor lock-in.
For instance, an enterprise may use separate cloud providers for infrastructure (IaaS), platform (PaaS), software (SaaS) and container (FaaS) services. In the latter case, they may use different infrastructure providers for different workloads, deploy a single workload load balanced across multiple providers (active-active), or deploy a single workload on one provider, with a backup on another (active-passive).
Advantages and challenges
There are several advantages to using a multicloud approach, including the ability to negotiate better pricing with cloud providers, the ability to quickly switch to another provider if needed, and the ability to avoid vendor lock-in. Multicloud can also be a good way to hedge against the risks of obsolescence, as it allows you to rely on multiple vendors and open standards, which can prolong the life of your systems.
Additional benefits of the multicloud architecture include adherence to local policies that require certain data to be physically present within the area/country, geographical distribution of processing requests from physically closer cloud unit which in turn reduces latency and protect against disasters.
Various issues and challenges also present themselves in a multicloud environment. Security and governance is more complicated, and more "moving parts" may create resiliency issues.
Difference be |
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