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https://en.wikipedia.org/wiki/Rees%20decomposition | In commutative algebra, a Rees decomposition is a way of writing a ring in terms of polynomial subrings. They were introduced by .
Definition
Suppose that a ring R is a quotient of a polynomial ring k[x1,...] over a field by some homogeneous ideal. A Rees decomposition of R is a representation of R as a direct sum (of vector spaces)
where each ηα is a homogeneous element and the d elements θi are a homogeneous system of parameters for R and
ηαk[θfα+1,...,θd] ⊆ k[θ1, θfα].
See also
Stanley decomposition
Hironaka decomposition
References
Commutative algebra |
https://en.wikipedia.org/wiki/Critical%20mathematics%20pedagogy | Critical mathematics pedagogy is an approach to mathematics education that includes a practical and philosophical commitment to liberation. Approaches that involve critical mathematics pedagogy give special attention to the social, political, cultural and economic contexts of oppression, as they can be understood through mathematics. They also analyze the role that mathematics plays in producing and maintaining potentially oppressive social, political, cultural or economic structures. Finally, critical mathematics pedagogy demands that critique is connected to action promoting more just and equitable social, political or economic reform.
Critical mathematics pedagogy builds on critical theory developed in the post-Marxist Frankfurt School, as well as critical pedagogy developed out of critical theory by Brazilian educator and educational theorist Paulo Freire. Definitions of critical mathematics pedagogy and critical mathematics education differ among those who practice it and write about it in their work. The focus of critical mathematics pedagogy shifts between three core tenets, but always includes some attention to all three: (1) analysis of injustice and inequitable relations of power made possible through mathematics, (2) critiques of the ways in which mathematics is used to structure and maintain power, and (3) critiques toward plans of action for change and the use of mathematics to reveal and oppose injustices, as well as imagine proposals for more equitable and just relations.
Core concepts and foundations
Critical theory and critical mathematics
Those who build their critical mathematics pedagogy with close relations to critical theory, focus on the analysis of mathematics as having "formatting power" that shapes the way we understand and organize the world. The assumption underlying critical mathematics pedagogy that comes from critical theory is the notion that mathematics is not neutral. According to critical mathematics, neither mathematics itself |
https://en.wikipedia.org/wiki/Karl%20Schr%C3%B6ter | Karl Walter Schröter (7 September 1905 in Biebrich near Wiesbaden – 22 August 1977 in Berlin) was a German mathematician and logician. Later on, after the war, he made important contributions concerning semantic consequences () and provability logic (). He worked as a mathematical theoretician and cryptanalyst for the civilian Pers Z S, the cipher bureau of the Foreign Office (), from Spring 1941 to the end of World War II.
Personal life
From 1928 to 1936, Schröter studied mathematics, physics, philosophy, and psychology at the Universities of Göttingen, Heidelberg and Frankfurt am Main. Due to family reasons he had to interrupt his studies several times. He then worked in the mathematical logic group at the University of Münster led by Heinrich Scholz. From 1 April 1939 he was a research assistant at the Department of Philosophy at the University of Münster. On 20 December 1941 he took his examination for promotion of Dr. phil under the logician Heinrich Scholz studying mathematics, logic, and calculus with a thesis titled Ein allgemeiner Kalkülbegriff (). On 1 April 1941 he took a leave of absence to join Pers Z S, the Foreign Office civilian cipher bureau, working as a mathematician. However, even during this time he continued to work on problems of basic mathematical research.
On 19 March 1943 he presented the application to the Faculty of Philosophy and Natural Sciences, with the publication Axiomatisierung der Fregeschen Aussagenkalküle (), to be admitted to his Habilitation. On the basis of the positive opinions of Heinrich Scholz and Adolf Kratzer, the degree of Doctor rerum naturalium habilitatus was awarded to him by certificate of 22 May 1943. On 9 June 1943 the report on the completed Habilitation was given to the Reich Minister. On 1, 2 and 3 July 1943 he held a public trial lecture on the topic Der Nutzen der mathematischen Logik für die Mathematik () as a prerequisite for a civil service position as a lecturer. On 18 August 1943 he was appointed lec |
https://en.wikipedia.org/wiki/Miguel%20San%20Mart%C3%ADn | Alejandro Miguel San Martín (January 6, 1959) is an Argentine engineer of NASA and a science educator. He is best known for his work as Chief Engineer for the Guidance, Navigation, and Control system in the latest missions to Mars. His best known contribution is the Sky Crane system, of which he is coinventor, used in the Curiosity mission for the descent of the rover.
In addition to his work as an engineer, he is dedicated to giving presentations about the work he does with his team at NASA. He has participated as a speaker at various events such as Campus Party, Robotics Day, Real Talks Atlanta and TEDx Río de la Plata, among other conferences. He is featured in the NASA video "Curiosity Seven Minutes of Terror" along with other Curiosity engineers.
Early life and career
He left Argentina after he graduated from industrial school, moving to the United States to get a bachelor's degree in electrical engineering from Syracuse University College of Engineering and Computer Science, being named Engineering Student of the Year. He completed his master's degree at the Massachusetts Institute of Technology.
In various interviews he said that he decided to be a space engineer on a winter's night in 1976 at his parents’ farm, while he listened to the BBC on short wave reporting the arrival of the Viking mission to Mars.
He started working for the NASA Jet Propulsion Laboratory in 1985, where he participated in the Magellan mission to Venus and Cassini mission to Saturn. Later in the Pathfinder mission he was named Chief Engineer for the Guidance, Navigation, and Control system, which landed Sojourner rover. In the same role he was part of the Spirit and Opportunity missions in 2004. He helped to develop the Sky Crane system which landed Curiosity on Mars as part of the Mars Science Laboratory mission, and with his team at JPL he also worked on the software for the landing.
He is a member of the NASA National Engineering and Safety Center.
In February 2019, he was |
https://en.wikipedia.org/wiki/Infomaniak | Infomaniak is Switzerland's largest web-hosting company, also offering live-streaming and video on demand services.
History
The company started as a user group founded in 1990 by Boris Siegenthaler in the Canton of Geneva, offering a bulletin board system to its members. In 1994, Siegenthaler and fellow developer Fabian Lucchi opened the Siegenthlaer & Lucchi computer store in the Genevan suburb of Châtelaine. They offered low-cost, custom-built computers – acting as an alternative to the larger distributors available at the time. The same year, the pair purchased a modem and 64 kbs line, becoming the first privately owned Internet service provider in the canton (after CERN and the University of Geneva). From 1995 on and for a few months, the store offered complimentary internet access to all customers who purchased a computer with them.
In May 1997, Infomaniak became a fully-fledged ISP with the creation of TWS Infomaniak SA – the company developed its offer based on low-cost internet access and web-hosting services alongside its staple of computer equipment retail.
On 1 January 1998, the Swiss state monopoly on telecom services came to an end and new providers were allowed onto the Swiss market. Sunrise, a joint-venture between Tele Danmark and BT, started offering free internet access services, forcing the company to revise its strategy: in 1999, TWS Infomaniak was reincorporated to create Infomaniak Network. They specialised in web-hosting services for private users and small and medium-sized enterprises, including basic.ch, the first Swiss web radio.
By 2003, Infomaniak was the largest web-host in Western Switzerland, and by July 2005, it was the largest web-radio broadcaster in Western Switzerland and France.
In 2007, the company created and launched their sustainability charter. As a result, it implemented a number of key measures including joining an ethical pension fund on behalf of its employees, a commitment to sustainable travel, and donating 1% of |
https://en.wikipedia.org/wiki/Surface%20Studio | The Surface Studio is an all-in-one PC, designed and produced by Microsoft as part of its Surface series of Windows-based personal computing devices. It was announced at the Windows 10 Devices Event on October 26, 2016, with pre-orders beginning that day.
The first desktop computer to be manufactured entirely by Microsoft, the Surface Studio uses the Windows 10 operating system with the Anniversary Update preinstalled. However, it is optimized for the Windows 10 Creators Update, which was released on April 11, 2017. The product, starting at $2,999, is aimed primarily at people in creative professions such as graphic artists and designers.
Two years later, in October 2018, Microsoft announced its successor, the Surface Studio 2.
Features
Hardware
The Surface Studio has a 28-inch 4.5K "PixelSense" display with 4500 x 3000 pixels, equivalent to 192 dpi. The screen, the thinnest ever built for an all-in-one PC at 12.5 millimetres thick, is capable of being used in both the DCI-P3 and sRGB color spaces, and features a unique hinge design that allows it be tilted to a flat position, in a manner similar to the Wacom Cintiq. The bezel of the display contains a 5.0 megapixel camera and a Windows Hello-compatible backlit infrared camera.
The CPU is located in the base. Its compact design contains a 6th generation (codename "Skylake") Intel Core i5 or Core i7 processor and either a NVIDIA GeForce GTX 965M or GeForce GTX 980M graphics processor (both dependent on configuration). The system can be configured with up to 32 GB of DDR4 RAM and a 2 terabyte hard drive. It also features four USB 3.0 ports, a Mini DisplayPort, an SDXC card reader and a headset connection.
Unlike many desktop PCs, the Surface Studio supports Microsoft's Modern Standby (formerly known as InstantGo) specification, enabling background tasks to operate while the computer is sleeping. A firmware update was released in April 2017 that enabled Cortana to be summoned via a "Hey, Cortana" voice command fr |
https://en.wikipedia.org/wiki/Tore%20Dyb%C3%A5 | Tore Dybå (born 31 July 1961) is a Norwegian scientist and software engineer in the fields of information systems and computer science. He has been a Chief Scientist at SINTEF ICT since 2003.
Career
Dybå received his Master of Science in Electrical Engineering and Computer Science from the Norwegian Institute of Technology in 1987. In 2001 he received his Doctoral degree (PhD) in Computer and Information Science from the Norwegian University of Science and Technology.
He worked as a software engineer and consultant in Norway and Saudi Arabia from 1987 until 1994 when he moved to SINTEF. Dybå had an adjunct position at the Simula Research Laboratory from 2002 to 2009, and from 2010 until 2015 he was a Professor of Software Engineering at the Department of Informatics at the University of Oslo.
Research
Dybå's research is related to organizational and socio-technical aspects of software development and how software development can be improved. He has been particularly concerned with combining rigorous research with topics of importance to the software industry, including software process improvement, agile software development and management, and empirical methods for software engineering.
Awards
For the period 2001–2012, the Journal of Systems and Software ranked Dybå as the top scholar worldwide in agile software development. The ranking named Dybå as the most active researchers by total articles in the period as well as the most cited researcher by total number of citations and adjusted citations.
In 2014 Dybå, together with Kitchenham and Jørgensen, received the Association for Computing Machinery's ACM SIGSOFT award for the most influential paper in the last ten years for the initial paper on evidence-based software engineering.
Dybå et al.’s article on evidence-based software engineering for practitioners was chosen by the editorial and advisory boards of IEEE Software as one of the magazine's 25th anniversary top picks of recommended reading.
Selected |
https://en.wikipedia.org/wiki/Processing%20aid | A processing aid is a substance used in the production of processed food, and which may end up in the finished product, but which is not, by law, required to be disclosed to the consumer as an ingredient.
Ethical concerns
NGOs, journalists, and food writers have raised concerns that the current laws on processing aids amount to a loophole that enables food producers to avoid transparency, and thereby to deceive consumers as to the contents of their food.
Jurisdictions
United Kingdom
Under the United Kingdom food labelling regulations, a "processing aid" is defined as follows:
United States
Under the law of the United States of America, a substance is legally a "processing aid" and can be excluded from ingredients labels if it meets any of the following criteria:
References
Food processing |
https://en.wikipedia.org/wiki/UNESCO-Equatorial%20Guinea%20International%20Prize%20for%20Research%20in%20the%20Life%20Sciences | The UNESCO-Equatorial Guinea International Prize for Research in the Life Sciences a scientific prize launched in 2012 by UNESCO to reward scientific research in the life sciences leading to improving the quality of human life.
Laureates
2012
Maged Al-Sherbiny, Egypt
Felix Dapare Dakora, South Africa
Rossana Arroyo, Mexico
2014
Hossein Baharvand (Iran)
André Bationo (Burkina-Faso)
Instituto de Medicina Tropical von Humboldt (IMT) at Universidad Peruana Cayetano Heredia
2015
Manoel Barral-Netto (Brazil)
Balram Bhargava (India)
Amadou Alpha Sall (Senegal)
2017
Agricultural Research Organisation at the Volcani Centre Israel
Rui Luis Gonçalves dos Reis (Portugal)
Ivan Antonio Izquierdo (Brazil)
2019
Cato Laurencin (USA)
Kevin McGuigan (Ireland)
Youyou Tu (China)
2022
Li Lanjuan (China)
Chad Mirkin (USA)
Christofer Toumazou (England)
See also
List of biology awards
References
Biology awards
Awards established in 2012
UNESCO awards |
https://en.wikipedia.org/wiki/Andy%20Lomas | Andy Lomas (born 1967 in Welwyn Garden City, England) is a British artist with a mathematical background, formerly a television and film CG supervisor and more recently a contemporary digital artist, with a special interest in morphogenesis using mathematical morphology.
Lomas previously worked on visual effects using computer graphics (CGI) for television and films such as The Matrix Reloaded (2003), The Matrix Revolutions (2003) and Avatar (2009). before becoming a digital artist. In 2006 he appeared in The Tech of 'Over the Hedge''', a short documentary. With his collaborators, in 1999 Lomas won the 51st Primetime Emmy Awards Outstanding Special Visual Effects for a Miniseries or a Movie for the 1999 film Alice in Wonderland.
Lomas's works are displayed in the form of videos, still images, and sculptures, produced using a mathematical programming approach. Some works include collaborative music, by Max Cooper for example. His artworks are inspired by the work of Ernst Haeckel, D'Arcy Thompson, and Alan Turing.
Lomas won the 2014 international Lumen Prize Gold Award for digital art, the top category. He has exhibited at the Butler Institute of American Art (Youngstown, Ohio, USA), the Computing Commons Art Gallery (Arizona State University), the Los Angeles Center for Digital Art, and SIGGRAPH.
In June–July 2016, Lomas held a solo exhibition of his work at the Watermans Arts Centre in west London, which has been acquired by the Victoria and Albert Museum for its collection. His work is also held in the D'Arcy Thompson Zoology Museum art collection at the University of Dundee in Scotland, funded by the UK Art Fund. In 2019, he contributed a chapter to the book Museums and Digital Culture''.
By way of summarizing his technique, Lomas counts himself among those who have entered into a "hybrid" relationship with the computer, wherein the latter is used to quickly generate a series of visual images based on an original idea or algorithm.
References
External lin |
https://en.wikipedia.org/wiki/Dainton%20Report | The Dainton Report was a 1968 British government report on secondary schools in the UK, also known as The Swing away from Science.
History
The report was produced in March 1968 by Frederick Dainton, Baron Dainton FRS, who was the Vice-Chancellor of the University of Nottingham. In October 1966 there were 1,600 vacant places in the science and technology faculties of British universities. Sheffield-born Fred Dainton was a Professor of Chemistry for fifteen years, researching radiation chemistry, and was later knighted in 1971. He died in December 1997.
The report was published by the Dainton Committee of the Department for Education and Science. The Dainton Committee was formed in 1965 by the Council for Scientific Policy.
Content
The report found that there was a reduction in the numbers of people entering science and engineering at university. The report was also known as the Enquiry into the Flow of Candidates in Science and Technology into Higher Education.
Around 40,000 of those at sixth-form were studying science in 1964; he predicted this would lower to around 30,000 in 1971, when the total numbers in sixth-form would rise from 107,000 to 130,000. One fifth of those taking science at sixth-form were female. In 1962 around 42% were opting for science at school, but by 1967 it was 31%; it was predicted this would lower to 25% by 1971. 45.9% of university admissions were to science courses, which had lowered to 40.6% in 1967. At the same time, those opting to study social sciences at university was rapidly increasing, doubling in proportion from 1962 to 1967.
The report wanted to improve the position of science, technology, and engineering in the education system, and society. The report wanted to increase the supply of scientists and technologists, which the report claimed, was limited by the immature and misinformed choices of 13 and 14 year olds at school, making premature decisions, often unfavourable to a career in science or technology. The report clai |
https://en.wikipedia.org/wiki/D%27Arcy%20Thompson%20Zoology%20Museum | The D'Arcy Thompson Zoology Museum is a museum of zoology at the University of Dundee in Scotland.
The museum is named after the Scottish biologist and mathematician D'Arcy Thompson (1860–1948), who founded it in the 1880s. Thompson began acquiring specimens for a museum immediately on taking up the post of Professor of Biology at what was then University College, Dundee in 1885. An extension to his department in 1893 allowed the creation of a purpose-built museum, which grew to become one of the largest museums of its kind in Britain at the time.
The original museum building was demolished along with its neighbours in 1956–57 to make way for the Tower Building, and much of Thompson's original collection was dispersed. The remaining material was kept in storage for many years before new museum displays were created in the Biological Sciences Institute in the 1980s. This building was itself later demolished, and in 2007 a new museum was created in the Carnelley Building, formally named the D’Arcy Thompson Zoology Museum after its founder.
The museum has a collection of birds, fish, insects, mammals, and reptiles from around the world, together with many of D'Arcy Thompson's original models and teaching aids, including Glass Sea Creatures by Leopold and Rudolf Blaschka and model and fluid preparations by Vaclav Fric. Many of the specimens and models relate to Thompson's interest in mathematical biology, which led to his celebrated book On Growth and Form.
The museum has 27 specimens from the voyage of of 1872–1876 and material from several other notable expeditions including the Dundee Antarctic Expedition of 1892–3, the Ingolf Expedition of 1895–6, the Nimrod Expedition of 1907-9 and the Discovery Investigations of the 1930s. There are also specimens of various extinct species including Huia and Thylacine.
The museum also has an art collection inspired by the work of D'Arcy Thompson including his 1917 book On Growth and Form, part of which was funded by the UK |
https://en.wikipedia.org/wiki/Quahog%20parasite%20unknown | The quahog parasite unknown, or QPX, is a single-celled protist parasite in the class Labyrinthulomycota that affects hard clams (Mercenaria mercenaria; quahogs), both cultured and wild.
Parasites similar to QPX were first observed in New Brunswick, Canada, in 1959, when a mass death of hard clams was observed. Outbreaks have also occurred in Nova Scotia, Prince Edward Island, New York, New Jersey, Massachusetts, and Virginia, always only in quahog clams.
Symptoms of QPX include chipping of the shells, mantle swelling, stunted shell growth and the development of nodules.
Biology
The life stages of thalli, endospores, and sporangia have been observed. It somewhat resembles the unrelated protist haplosporidian parasite Haplosporidium nelsoni (MPX), a pathogen of the eastern oyster.
QPX was originally considered a chytrid, but has now been provisionally assigned to the phylum Labyrinthulomycota in either the families Thraustochytriidae or Labyrinthulidae, based on the organism having a "uninucleate biflagellate zoospore stage, a loose multilaminar cell wall, and particularly an intracellular sagenogen-like structure". However, much about it is still unknown. QPX-like organisms also may not be all of the same species.
Molecular phylogenetic on the SSU rRNA of QPX was able to produce the same phylum-level identification, and more precisely down to the family Thraustochytriidae next to Thraustochytrium pachydermum. A PCR primer targeting this region that detects QPX infection has been constructed.
QPX can be cultured in laboratories, with the optimal temperature being 20 to 23 °C. It produces a mucus that causes inflammation in the clam and shields itself from clam immune response.
Control and epidemiology
Genetics
The partial genome of QPX has been sequenced by the shotgun method in 2013, along with the transcriptome to identify genes important in stress response (mainly temperature). A few interesting proteins and a wide range of genetic polymorphisms have bee |
https://en.wikipedia.org/wiki/Non-ITU%20prefix | Prefixes that are used for radio and television are usually allocated by ITU. They also form the basis for, but do not exactly match, aircraft registration identifiers. But in some cases, especially among amateur radio operators other, by ITU unallocated, callsigns are used when operating from disputed areas or countries that are internationally not (yet) recognized.
They can be:
unofficial - used by individuals without any issued permit
temporary - issued by local authority
official - recognized internationally by different organisations
Prefixes for those stations are either unallocated or unavailable by ITU definitions.
ITU unallocated and unavailable call sign prefixes
Unallocated: The following call sign prefixes are available for future allocation by the ITU. (x represents any letter; n represents any digit from 2–9.)
E8, E9, H5, J9, On, S4, T9*, Un, V9, Xn, YZ*, Z4–Z7, Z9, 4N*.
(* Indicates a prefix that has recently been returned to the ITU.)
Unavailable: Under present ITU guidelines the following call sign prefixes shall not be allocated .
(x represents any letter; n represents any digit from 2–9.)
nn, x0, x1, 0x, 1x, Qx.
no prefixes beginning with Q are used—they may be confused with Q codes.
no prefixes with the digits 1 or 0 are used—they may be confused with the letters I or O.
two digit prefixes (nn) are not as yet considered by the ITU.
Table of Non-ITU radio prefixes
See also
ITU prefix
Amateur radio call signs
Aircraft registration
References
External links
Article: Kosovo - New DXCC entity?
Prefix List (by CT2FZI)
Northern Cyprus 1B: radio amaterur or radio pirate?
Article: 1A: DX Entity with a 900 Year History
Operational Bulletin No. 1149 (1.VI.2018)
Call signs
Amateur radio call signs |
https://en.wikipedia.org/wiki/Citrix%20Cloud | Citrix Cloud is a cloud management platform that allows organizations to deploy cloud-hosted desktops and apps to end users. It was developed by Citrix Systems and released in 2015.
Overview
Citrix Cloud is a cloud-based platform for managing and deploying Citrix products and desktops and applications to end users using any type of cloud, whether public, private or hybrid, or on-premises hardware. The product supports cloud-based versions of every major Citrix product. These can be accessed together as an integrated "workspace" or independently.
Features
Citrix Cloud enables cloud services for Citrix products XenApp, XenDesktop, XenMobile, ShareFile, and NetScaler. In addition, Citrix has developed several cloud-native services, including its Secure Browser Service.
Citrix Cloud is compatible with any device and cloud or data center and can be synced via Citrix Cloud Connector. As of May 2016, Citrix states that Microsoft Azure is its preferred cloud partner. Citrix platforms reside in Citrix Cloud, however other applications and resources may make use of other clouds and infrastructures. A company's IT department retains the ability to choose a custom combination of data centers and cloud providers. Citrix continuously updates Citrix Cloud so that users are automatically running the most current version.
As of 2015, Citrix Cloud offers four different service packages.
History
Citrix Workspace Cloud was announced in May 2015 at the company's industry conference, Citrix Synergy. The offering launched in August 2015 with four core services: App and Desktop Service, Lifecycle Management, Secure Documents, and Mobility. The company positioned Workspace Cloud as an alternative to XenDesktop and XenApp, the company's traditional desktop and application virtualization platforms.
The company renamed Citrix Workspace Cloud to Citrix Cloud in May 2016.r In addition, cloud services were renamed with cloud-based versions of other Citrix products. XenDesktop and XenApp Se |
https://en.wikipedia.org/wiki/Lebesgue%27s%20universal%20covering%20problem | Lebesgue's universal covering problem is an unsolved problem in geometry that asks for the convex shape of smallest area that can cover every planar set of diameter one. The diameter of a set by definition is the least upper bound of the distances between all pairs of points in the set. A shape covers a set if it contains a congruent subset. In other words the set may be rotated, translated or reflected to fit inside the shape.
Formulation and early research
The problem was posed by Henri Lebesgue in a letter to Gyula Pál in 1914. It was published in a paper by Pál in 1920 along with Pál's analysis. He showed that a cover for all curves of constant width one is also a cover for all sets of diameter one and that a cover can be constructed by taking a regular hexagon with an inscribed circle of diameter one and removing two corners from the hexagon to give a cover of area
In 1936, Roland Sprague showed that a part of Pál's cover could be removed near one of the other corners while still retaining its property as a cover. This reduced the upper bound on the area to .
Current bounds
After a sequence of improvements to Sprague's solution, each removing small corners from the solution,
a 2018 preprint of Philip Gibbs claimed the best upper bound known, a further reduction to area 0.8440935944.
The best known lower bound for the area was provided by Peter Brass and Mehrbod Sharifi using a combination of three shapes in optimal alignment, proving that the area of an optimal cover is at least 0.832.
See also
Moser's worm problem, what is the minimum area of a shape that can cover every unit-length curve?
Moving sofa problem, the problem of finding a maximum-area shape that can be rotated and translated through an L-shaped corridor
Kakeya set, a set of minimal area that can accommodate every unit-length line segment (with translations allowed, but not rotations)
Blaschke selection theorem, which can be used to prove that Lebesgue's universal covering problem has a so |
https://en.wikipedia.org/wiki/JShell | JShell is a Java read-eval-print loop which was first introduced in the JDK 9. It is tracked by JEP 222 jshell: The Java Shell (Read-Eval-Print Loop). One reason why JShell was proposed for Java 9 is the lack of a standard interactive environment for the language; the de facto library to use a Java REPL was often BeanShell, which has been dormant since 2003, and arbitrarily diverged from the Java language.
Example
jshell> int a[] = {0,1,3,5,8}
a ==> int[5] { 0, 1, 3, 5, 8 }
jshell> int fact(int n){
...> return n<2?1:n*fact(n-1);
...> }
| created method fact(int)
jshell> for (int i=0 ; i<a.length ; ++i)
...> a[i] = fact(a[i]);
jshell> a
a ==> int[5] { 1, 1, 6, 120, 40320 }
See also
Exploratory programming
References
Command shells
Cross-platform software
Virtual machine
Java platform software
Interpreters (computing) |
https://en.wikipedia.org/wiki/Fronthaul | The fronthaul portion of a C-RAN (Cloud Radio Access Network) telecommunications architecture comprises the intermediate links between the centralized radio controllers and the radio heads (or masts) at the "edge" of a cellular network. In recent years fronthaul is becoming more essential as 5G becomes more mainstream.
In general it is coincident with the backhaul network, but subtly different. Technically in a C-RAN the
backhaul data is only decoded from the fronthaul network at the centralised controllers, from where it is then transferred to the core network.
It comprises dedicated fibers carrying data in the CPRI or OBSAI format. This fiber network is either owned or leased by the mobile network operator. In the UK for example BT Openworld owns a majority of the fiber network to radio masts. There are proposals to modify Ethernet to make it more suitable for the Fronthaul network.
Recently, a novel wireless fronthaul solution has been proposed for ultra-dense small cell deployment where networked flying platforms (NFPs) such UAVs, drones, tethered balloon and high-altitude/medium-altitude/low-altitude platforms carrying FSO transceivers have been introduced as aerial hubs to aggregate the small cell traffic and offer connectivity to the core network.
Further reading
Backhaul
C-RAN
Wireless networks
E-Band
References
Telecommunications infrastructure
Network architecture
Wireless networking |
https://en.wikipedia.org/wiki/Omega2%20%28computer%29 | The Onion Omega series of personal single-board computer created by a startup company called Onion that is based in Boston, Toronto and Shenzhen. It is advertised as "the world's smallest Linux Server". The system combines a tiny form factor and power-efficiency with the power of a general purpose Operating System. They ship with a Linux kernel based lightweight operating system for embedded systems called OpenWRT, but is capable of running other lightweight Unix-based operating systems.
The first shipments of the Onion Omega went out in October, 2015.
History
Omega2 is the next generation of the old product Onion makes, Omega. The original Omega was based on the Qualcomm Atheros AR9331 (MIPS architecture) SoC which runs a full Linux operating system designed for embedded system and sold for $19.99. The company has discontinued development of the Omega, and replaced it with the successor, Omega2, using another SoC chip - Mediatek MT7688 which also has a metal cover over the chip. They have also drastically cut the price to $5 (but later increased it to $7.5).
As of the beginning of 2017, Onion has already attracted crowdfunding of more than $850,000 for the Omega2, which has greatly exceeded their initial goal of $440,000.
Hardware Features
Omega2 comes in two versions, the basic Omega2 and Omega2 Plus. Omega2 CPU is based on MIPS architecture running at 580 MHz clock speed, equipped with 64 MB of RAM and 16 MB of flash memory. Omega2 Plus is similar to Omega2, except it has 128 MB RAM and 32 MB memory and a MicroSD slot, sold for $9 USD. The system comes in a small PCB footprint with dual-in-line 16x2mm pins. The board runs at 3.3 volts with an average power consumption of 0.6W. The devices are intended for as headless computers with no graphical interfaces in Embedded systems.
References
External links
Official website
MIPS32 Architecture
2016 establishments in the United States
Educational hardware
Linux-based devices
MIPS architecture
Products |
https://en.wikipedia.org/wiki/Universal%20chord%20theorem | In mathematical analysis, the universal chord theorem states that if a function f is continuous on [a,b] and satisfies , then for every natural number , there exists some such that .
History
The theorem was published by Paul Lévy in 1934 as a generalization of Rolle's Theorem.
Statement of the theorem
Let denote the chord set of the function f. If f is a continuous function and , then
for all natural numbers n.
Case of n = 2
The case when n = 2 can be considered an application of the Borsuk–Ulam theorem to the real line. It says that if is continuous on some
interval with the condition that , then there exists some such that .
In less generality, if is continuous and , then there exists that satisfies .
Proof of n = 2
Consider the function defined by . Being the sum of two continuous functions, is continuous, . It follows that and by applying the intermediate value theorem, there exists such that , so that . Which concludes the proof of the theorem for
Proof of general case
The proof of the theorem in the general case is very similar to the proof for
Let be a non negative integer, and consider the function defined by . Being the sum of two continuous functions, is continuous. Furthermore, . It follows that there exists integers such that
The intermediate value theorems gives us c such that and the theorem follows.
See also
Intermediate value theorem
Borsuk–Ulam theorem
Rolle's theorem
References
Mathematical theorems |
https://en.wikipedia.org/wiki/Secant%20plane | A secant plane is a plane containing a nontrivial section of a sphere or an ellipsoid, or such a plane that a sphere is projected onto. Secant planes are similar to tangent planes, which contact the sphere's surface at a point, while secant planes contact the surface along curves.
The two-dimensional representations of secant planes are secant lines, the lines that join two distinct points on a curve.
Applications
Secant planes are used in map projections. The secant plane intersects a globe along a small circle with no distortion, forming a standard parallel which has true scale.
See also
Circular section
Circular segment
Spherical cap
Tangent space
References
External links
Tangents and Secants in Map Projections
Planes (geometry) |
https://en.wikipedia.org/wiki/CD4%2B/CD8%2B%20ratio | The CD4+/CD8+ ratio is the ratio of T helper cells (with the surface marker CD4) to cytotoxic T cells (with the surface marker CD8). Both CD4+ and CD8+ T cells contain several subsets.
The CD4+/CD8+ ratio in the peripheral blood of healthy adults and mice is about 2:1, and an altered ratio can indicate diseases relating to immunodeficiency or autoimmunity. An inverted CD4+/CD8+ ratio (namely, less than 1/1) indicates an impaired immune system. Conversely, an increased CD4+/CD8+ ratio corresponds to increased immune function.
Obesity and dysregulated lipid metabolism in the liver leads to loss of CD4+, but not CD8+ cells, contributing to the induction of liver cancer. Regulatory CD4+ cells decline with expanding visceral fat, whereas CD8+ T-cells increase.
Decreased ratio with infection
A reduced CD4+/CD8+ ratio is associated with reduced resistance to infection.
Patients with tuberculosis show a reduced CD4+/CD8+ ratio.
HIV infection leads to low levels of CD4+ T cells (lowering the CD4+/CD8+ ratio) through a number of mechanisms, including killing of infected CD4+. Acquired immunodeficiency syndrome (AIDS) is (by one definition) a CD4+ T cell count below 200 cells per µL. HIV progresses with declining numbers of CD4+ and expanding number of CD8+ cells (especially CD8+ memory cells), resulting in high morbidity and mortality. When CD4+ T cell numbers decline below a critical level, cell-mediated immunity is lost, and the body becomes progressively more susceptible to opportunistic infections. Declining CD4+/CD8+ ratio has been found to be a prognostic marker of HIV disease progression.
COVID-19
In COVID-19 B cell, natural killer cell, and total lymphocyte counts decline, but both CD4+ and CD8+ cells decline to a far greater extent. Low CD4+ predicted greater likelihood of intensive care unit admission, and CD4+ cell count was the only parameter that predicted length of time for viral RNA clearance.
Decreased ratio with aging
A declining CD4+/CD8+ ratio i |
https://en.wikipedia.org/wiki/Flex%20sensor | A flex sensor or bend sensor is a sensor that measures the amount of deflection or bending. Usually, the sensor is stuck to the surface, and resistance of sensor element is varied by bending the surface. Since the resistance is directly proportional to the amount of bend it is used as goniometer, and often called flexible potentiometer.
Types of flex sensor
Conductive ink based flex sensor
Fibre optic flex sensor
Capacitive flex sensor
Velostat flex sensor (popular among hobbyists)
Applications
Flex sensors are used in wide areas of research from computer interfaces, rehabilitation, security systems and even music interfaces. It is also famous among students and hobbyists.
Human Machine Interface devices
A dataglove is human-computer interaction device that is made possible by flex sensors. Deflections of a dataglove are measured via its flex sensors embedded in the glove.
Rehabilitation Research
In rehabilitation research, wired gloves or datagloves are used to record joint movement.
Security Systems
Movement of doors is monitored by placing the sensor at the hinge. Also, damage to metal structures can be identified using the sensor.
References
Sensors |
https://en.wikipedia.org/wiki/VEX%20Robotics | VEX Robotics is a robotics program for elementary through university students and a subset of Innovation First International. The VEX Robotics competitions and programs are managed by the Robotics Education & Competition Foundation (RECF). In April 2018, VEX Robotics Competition was named the largest robotics competition in the world by Guinness World Records.
There are three leagues of VEX robotics competitions meant for different age groups and skill levels:
VEX V5 (previously VEX EDR) is for middle and high school students. VEX V5 Robotics teams have an opportunity to compete annually in the VEX Robotics Competition (VRC)
VEX IQ is for elementary and middle school students. VEX IQ robotics teams have an opportunity to compete annually in the VEX IQ Robotics Competition (VIQRC).
VEX AI is an advanced robotics program for high school and university students. The pilot program registration is scheduled to open to university students in fall of 2020. VEX AI robotics teams will have an opportunity to compete in the VEX AI Competition (VAIC).
In each of the three leagues, students are given a new challenge annually and must design, build, program, and drive a robot to complete the challenge as best as they can. The robotics teams that consistently display exceptional mastery in all of these areas will eventually progress to the VEX Robotics World Championship.
The description and rules for the season's competition are released during the world championship of the previous season. Starting in 2021, the VEX Robotics World Championship has been held in Dallas, Texas each year in mid-April or mid-May, depending on which VEX team you're on.
VEX V5
VEX V5 is a STEM learning system designed by VEX Robotics and the REC Foundation to help middle and high school students develop problem-solving and computational thinking skills. It was introduced at the VEX Robotics World Championship in April 2019 as a replacement for a previous system called VEX EDR. The program utilizes |
https://en.wikipedia.org/wiki/Baltimore%20Underground%20Science%20Space | The Baltimore Underground Science Space (BUGSS) is a non-profit synthetic biology and biotechnology makerspace laboratory for science enthusiasts, hobbyists, and professionals to practice, share and learn about the biological sciences. BUGSS is closely aligned with do-it-yourself biology and the Maryland science community generally, and offers courses and lectures in addition to community lab space. It was founded by Dr. Tom Burkett in 2012. It is located in the Highlandtown neighborhood of Baltimore, Maryland.
BUGSS has regularly hosted teams for the annual International Genetically Engineered Machine (iGEM) competition. In 2014, the team focused on 3D bioprinting. In 2016, the team worked on isolating the genes in the bacterium Ideonella sakaiensis that allow it to consume the plastic PET, and introducing them into Escherichia coli.
BUGSS has 20-25 members in 2017.
References
External links
Official website
The Rise of Do-It-Yourself Biology: A Look at the Baltimore Underground Science Space (BUGSS) - a documentary film about the organization
Biotechnology organizations
2012 establishments in Maryland
Public laboratories
Non-profit organizations based in Maryland |
https://en.wikipedia.org/wiki/North%20South%20Atlantic%20Training%20Transect | The North South Atlantic Training Transect (NoSoAT) is a program developed by the Alfred Wegener Institute (AWI), the Strategic Marine Alliance for Research and Training (SMART), and the Partnership for Observation of the Global Oceans (POGO) to further the education and practical training of postgraduate students in climate and marine sciences. Each year, about 30 students are selected through a rigorous application process to join a voyage from Bremerhaven, Germany to Cape Town, South Africa aboard the RV Polarstern. The month-long course provides students with relevant lectures and projects, including hands-on training with atmospheric and oceanographic equipment, and instruction on data processing and analysis.
Results from Previous Cruises
Each cruise has a unique focus that varies from year to year as topics become more or less important. While the 2015 cruise had a strong focus on biological oceanography, the 2016 cruise was more focused on physical and chemical oceanography. These different approaches to studying marine and climate sciences allow groups of post-doctorate students to be specifically trained in their respective fields.
NoSoAT 2015 - Expeditions PS95.1 and PS95.2
The cruise track covered a broad range of habitats for various organisms and a broad range of characteristically different waters. Data collected came from equipment that included a Conductivity, Temperature, and Depth (CTD) Sonde; a Bongonet; a Ferrybox; and a Continuous Plankton Recorder (CPR). Samples of phytoplankton and zooplankton were obtained and analyzed in conjunction with satellite data. Preliminary results included the identification of three distinct water masses along the transect; discrepancies in the comparison of ship-board chlorophyll a measurements with satellite-derived chlorophyll a data; latitudinal variations in the depth of the chlorophyll a maximum; and variations in the impact of microzooplankton grazing on phytoplankton communities.
References
Marine bi |
https://en.wikipedia.org/wiki/Kea%20%28software%29 | Kea is an open-source DHCP server developed by the Internet Systems Consortium, authors of ISC DHCP, also known as DHCPd. Kea and ISC DHCP are both implementations of the Dynamic Host Configuration Protocol, a set of standards established by the Internet Engineering Task Force (IETF). Kea software is distributed in source code form on GitHub, from various ISC sites, and through a number of operating system packages. Kea is licensed under the Mozilla Public License 2.0.
The Kea distribution includes a DHCPv4 server, a DHCPv6 server, and a Dynamic DNS (DDNS) server. Significant features include: support for IPv6 prefix delegation, host reservations (which may be optionally stored in a separate back end database), Preboot Execution Environment (PXE) boot, client classification, shared networks, and high-availability (failover pairs). Kea can store leases locally in a memfile, or in a PostgreSQL or MySQLdatabase. Kea has a supported API for writing optional extensions, using 'hooks'.
Kea has a graphical management application, called Stork, that integrates an agent running on the Kea server, an exporter to a Prometheus time-series data store, a Grafana template for data visualization, and the Stork web dashboard. Like Kea, Stork is licensed under the MPL 2.0 license. The Stork dashboard provides a simple graphical display for managing one or many Kea servers. Current features include server status, pool utilization, high-availability status, host reservations, and leases per second. Via the integration with Grafana it also provides detailed statistics on DHCP messages over time. Stork was first released in 2014, and features are being added rapidly in monthly releases.
References
External links
Project repository and issue tracker
Project repository and issue tracker for Stork management dashboard.
Kea documentation on ReadTheDocs
Stork documentation on ReadTheDocs
ISC Kea packages
Unix network-related software
Servers (computing)
Free network-related soft |
https://en.wikipedia.org/wiki/Topological%20recursion | In mathematics, topological recursion is a recursive definition of invariants of spectral curves.
It has applications in enumerative geometry, random matrix theory, mathematical physics, string theory, knot theory.
Introduction
The topological recursion is a construction in algebraic geometry. It takes as initial data a spectral curve: the data of , where: is a covering of Riemann surfaces with ramification points; is a meromorphic differential 1-form on , regular at the ramification points; is a symmetric meromorphic bilinear differential form on having a double pole on the diagonal and no residue.
The topological recursion is then a recursive definition of infinite sequences of symmetric meromorphic n-forms on , with poles at ramification points only, for integers g≥0 such that 2g-2+n>0. The definition is a recursion on the integer 2g-2+n.
In many applications, the n-form is interpreted as a generating function that measures a set of surfaces of genus g and with n boundaries. The recursion is on 2-2g+n the Euler characteristics, whence the name "topological recursion".
Origin
The topological recursion was first discovered in random matrices. One main goal of random matrix theory, is to find the large size asymptotic expansion of n-point correlation functions, and in some suitable cases, the asymptotic expansion takes the form of a power series. The n-form is then the gth coefficient in the asymptotic expansion of the n-point correlation function. It was found that the coefficients always obey a same recursion on 2g-2+n. The idea to consider this universal recursion relation beyond random matrix theory, and to promote it as a definition of algebraic curves invariants, occurred in Eynard-Orantin 2007 who studied the main properties of those invariants.
An important application of topological recursion was to Gromov–Witten invariants. Marino and BKMP conjectured that Gromov–Witten invariants of a toric Calabi–Yau 3-fold are the TR invariants of a spe |
https://en.wikipedia.org/wiki/Eagle%20Flight | Eagle Flight is a virtual reality simulation video game developed by Ubisoft Montreal and published by Ubisoft. It was released for Microsoft Windows and PlayStation 4 in late 2016. Players must have a virtual reality headset, such as the Oculus Rift, PlayStation VR, or HTC Vive, in order to play the game.
The game is set fifty years after humanity's extinction, focusing on a post-apocalyptic version of Paris. Players assume control of an eagle, which must travel around the city and defeat rival animals in order to build its nest on five different landmarks. Gameplay revolves around players tilting their heads to control the movement of the eagle, and using sonar waves to defeat enemies. The game also features a six-player competitive multiplayer Capture the Flag-styled mode, and a cooperative multiplayer mode called Free Flight, which allows the player to explore the city with five other players.
Development of the game began in October 2014 after the completion of Far Cry 4. The game was greenlit in mid-2015, through Ubisoft's own idea-pitching platform, Fun House. The game was originally set in Notre Dame de Paris, but the scale was later expanded to include the entire city. To reduce the possibility of players suffering from motion sickness, the team researched extensively and read NASA's articles and documents on the subject. Inon Zur served as the game's composer; the soundtracks were described as "soaring and uplifting".
Announced at PlayStation Experience 2015, the game was the first virtual reality game developed by Ubisoft. It received mixed to positive reviews upon its release, with critics praising the game's controls, gameplay, and the competitive multiplayer mode, but criticizing the single-player mode and city's design.
Setting
In the near future, fifty years after humanity's extinction, wildlife in Paris is flourishing. Nature has reclaimed the land, and the city has become home to various animals and plants. As an eagle inhabiting the city, the |
https://en.wikipedia.org/wiki/Shadowverse | Shadowverse is a digital collectible card game developed and published by Cygames. It was released free-to-play for iOS and Android devices in June 2016. macOS and Windows versions were released in October 2016.
Shadowverse employs an anime art style with some illustrations reused from the developer's previous title, Rage of Bahamut, an earlier digital collectible card game released in 2012. The game has been compared favorably with Hearthstone (2014), a difference being that Cygames sought to minimize the impact of randomness on match outcomes. Another difference is Shadowverses "Evolve" game mechanic which allows players to grant played cards bonus stats and effects at the cost of an evolution point.
An anime television series adaptation by Zexcs aired from April 2020 to March 2021. A second anime series titled Shadowverse Flame has been announced. An RPG card game based on the anime, Shadowverse: Champion's Battle was released on the Nintendo Switch in Japan in November 2020. The game was released overseas on August 10, 2021.
Gameplay
Shadowverse matches are structured between two players taking turns playing cards from their deck. Each player is represented by a Leader with 20 defense and a starting hand of three cards. The player going first has two evolution points, and the player going second has three evolution points, can evolve one turn earlier, and draws an extra card at the player's first turn. The objective of the player is to reduce the other player's defense to zero or attain a win via certain cards (e.g. Enstatued Seraph or a Victory Card by playing Spartacus). Each player utilizes the Play Point resource to play cards. Both players begin at having zero play point orbs, and gain one play point orb at the beginning of the respective player's turn, up to a limit of 10. Play Point orbs are refilled at the beginning of each player's turn.
Development
New sets are added to Shadowverse at a regular interval of three months. The game launched with an i |
https://en.wikipedia.org/wiki/Eukaryogenesis | Eukaryogenesis, the process which created the eukaryotic cell and lineage, is a milestone in the evolution of life, since eukaryotes include all complex cells and almost all multicellular organisms. The process is widely agreed to have involved symbiogenesis, in which archaea and bacteria came together to create the first eukaryotic common ancestor (FECA). This cell had a new level of complexity and capability, with a nucleus, at least one centriole and cilium, facultatively aerobic mitochondria, sex (meiosis and syngamy), a dormant cyst with a cell wall of chitin and/or cellulose and peroxisomes. It evolved into a population of single-celled organisms that included the last eukaryotic common ancestor (LECA), gaining capabilities along the way, though the sequence of the steps involved has been disputed, and may not have started with symbiogenesis. In turn, the LECA gave rise to the eukaryotes' crown group, containing the ancestors of animals, fungi, plants, and a diverse range of single-celled organisms.
Context
Life arose on Earth once it had cooled enough for oceans to form. The last universal common ancestor (LUCA) was an organism which had ribosomes and the genetic code; it lived some 4 billion years ago. It gave rise to two main branches of prokaryotic life, the bacteria and the archaea. From among these small-celled, rapidly-dividing ancestors arose the Eukaryotes, with much larger cells, nuclei, and distinctive biochemistry. The eukaryotes form a domain that contains all complex cells and most types of multicellular organism, including the animals, plants, and fungi.
Symbiogenesis
According to the theory of symbiogenesis (also known as the endosymbiotic theory) championed by Lynn Margulis, a member of the archaea gained a bacterial cell as a component. The archaeal cell was a member of the Asgard group. The bacterium was one of the Alphaproteobacteria, which had the ability to use oxygen in its respiration. This enabled it – and the archaeal cells that |
https://en.wikipedia.org/wiki/Public%20Law%20114-216 | Public Law 114-216 is a federal law of the United States that regulates GMO food labeling. It was enacted on July 29, 2016 when President Obama signed then Senate Bill 764 (S.764). While the law is officially termed A bill to reauthorize and amend the National Sea Grant College Program Act, and for other purposes, it evolved over time into "the legislative vehicle for a measure concerning bioengineered food disclosure", which opponents have called the "DARK Act", an acronym for "Deny Americans the Right to Know Act".
Legislative history
The bill was crafted by Senator Pat Roberts (R-KS) and Debbie Stabenow (D-MI). The "GMO labeling bill" was introduced on 17 March 2015 by its sponsor, Sen. Roger F. Wicker (R-MS), cosponsored by Sen. Dan Sullivan (R-AK), and passed Senate and House in June 2016. The law overturned relevant state laws such as Vermont's GMO labeling law that had called for strict and transparent GMO food labeling in Vermont after July 1, 2016.
Labeling of GMO food is mandated in at least 64 countries, including most European countries, China, Russia, Japan, Brazil, South Africa, and Australia.
Contents
Senate resolution S.744 as originally introduced on 17 March 2015 contained no language to regulate bioengineered foods. A bill entitled "Safe and Accurate Food Labeling Act of 2015" was received in the Senate on 24 July 2015 and referred to the Committee on Agriculture, Nutrition, and Forestry (ANF), which resulted in the amendments to Public Law 114-216 seen now; this was done on 7 July 2016 to "establish a national bioengineered food disclosure standard", whereby bioengineered food (commonly referred to as genetically modified organism or GMO food) is defined as "food that has been genetically engineered in a way that could not be obtained through conventional breeding or found in nature".
Mitch McConnell introduced on 29 June 2016 the "Roberts GMO bill" named after Pat Roberts who was then Chair of the Committee on ANF, and Public Law 114-21 |
https://en.wikipedia.org/wiki/Permutational%20analysis%20of%20variance | Permutational multivariate analysis of variance (PERMANOVA), is a non-parametric multivariate statistical permutation test. PERMANOVA is used to compare groups of objects and test the null hypothesis that the centroids and dispersion of the groups as defined by measure space are equivalent for all groups. A rejection of the null hypothesis means that either the centroid and/or the spread of the objects is different between the groups. Hence the test is based on the prior calculation of the distance between any two objects included in the experiment.
PERMANOVA shares some resemblance to ANOVA where they both measure the sum-of-squares within and between group and make use of F test to compare within-group to between-group variance. However, while ANOVA bases the significance of the result on assumption of normality, PERMANOVA draws tests for significance by comparing the actual F test result to that gained from random permutations of the objects between the groups. Moreover, whilst PERMANOVA tests for similarity based on a chosen distance measure, ANOVA tests for similarity of the group averages.
Calculation of the statistic
In the simple case of a single factor with p groups and n objects in each group, the total sum-of-squares is determined as:
where is the total number of objects, and is the squared distance between objects i and j.
Similarly, the within groups sum-of-squares is determined as:
where is 1 if the observations i and j belong to the same group, and 0 otherwise.
Then, the between groups sum-of-squares () can be calculated as the difference between the overall and the within groups sum-of-squares:
Finally, a pseudo F-statistic is calculated:
where p is the number of groups.
Drawing significance
Finally, the PERMANOVA procedure draws significance for the actual F statistic by performing multiple permutations of the data. In each permutation the items are shuffled between groups, and the F-ratio is calculated for it, . The P-value |
https://en.wikipedia.org/wiki/Peter%20Lynch%20%28meteorologist%29 | Peter Lynch is an Irish meteorologist, mathematician, blogger and book author. His interests include numerical weather prediction, dynamic meteorology, Hamiltonian mechanics, the history of meteorology, and the popularisation of mathematics.
Life and career
Lynch was born in Dublin, and educated at University College Dublin, where he obtained his BSc (1968) and MSc (1969) in mathematical science. He enlisted in the Irish meteorological service (now known as Met Éireann) in 1971, and worked there until 2004, rising to the rank of Head of the Research and Training Division and later Deputy Director. In 1982, he was awarded a PhD by Trinity College Dublin for his thesis Planetary-scale Hydrodynamic Instability in the Atmosphere written under the supervision of Ray Bates.
In 2004, he moved to academia, becoming Met Éireann Professor of Meteorology at the School of Mathematical Sciences. He has supervised several doctoral theses there. He is now an Emeritus Professor at the School of Mathematical Sciences.
Shortly after formally retiring from UCD in 2011, he started writing a weekly mathematical blog called "That's Maths", about half of the columns also appearing in The Irish Times newspaper (on the first and third Thursdays of each month). Two books of collected columns have resulted, in 2016 and 2020, respectively.
Scientific meteorology
One of Lynch's principal interests is the scientific approach to weather forecasting and its history, for example publishing a 2000 paper called "Weather Forecasting: from woolly art to solid science". Lewis Fry Richardson pioneered mathematical techniques of weather forecasting and dreamed that weather prediction would one day be an exact science. Modern computers were not available in Richardson's day and further theoretical advances were needed before Richardson's dream could be a realised. Lynch examined this issue first in a 2008 paper, and later in his book The Emergence of Numerical Weather Prediction: Richardson's Dre |
https://en.wikipedia.org/wiki/Graph%20entropy | In information theory, the graph entropy is a measure of the information rate achievable by communicating symbols over a channel in which certain pairs of values may be confused. This measure, first introduced by Körner in the 1970s, has since also proven itself useful in other settings, including combinatorics.
Definition
Let be an undirected graph. The graph entropy of , denoted is defined as
where is chosen uniformly from , ranges over independent sets of G, the joint distribution of and is such that with probability one, and is the mutual information of and .
That is, if we let denote the independent vertex sets in , we wish to find the joint distribution on with the lowest mutual information such that (i) the marginal distribution of the first term is uniform and (ii) in samples from the distribution, the second term contains the first term almost surely. The mutual information of and is then called the entropy of .
Properties
Monotonicity. If is a subgraph of on the same vertex set, then .
Subadditivity. Given two graphs and on the same set of vertices, the graph union satisfies .
Arithmetic mean of disjoint unions. Let be a sequence of graphs on disjoint sets of vertices, with vertices, respectively. Then .
Additionally, simple formulas exist for certain families classes of graphs.
Complete balanced k-partite graphs have entropy . In particular,
Edge-less graphs have entropy .
Complete graphs on vertices have entropy .
Complete balanced bipartite graphs have entropy .
Complete bipartite graphs with vertices in one partition and in the other have entropy , where is the binary entropy function.
Example
Here, we use properties of graph entropy to provide a simple proof that a complete graph on vertices cannot be expressed as the union of fewer than bipartite graphs.
Proof By monotonicity, no bipartite graph can have graph entropy greater than that of a complete bipartite graph, which is bounded by . Thus, by sub-addit |
https://en.wikipedia.org/wiki/Radio%20acoustic%20ranging | Radio acoustic ranging, occasionally written as "radio-acoustic ranging" and sometimes abbreviated RAR, was a method for determining a ship's precise location at sea by detonating an explosive charge underwater near the ship, detecting the arrival of the underwater sound waves at remote locations, and radioing the time of arrival of the sound waves at the remote stations to the ship, allowing the ship's crew to use true range multilateration to determine the ship's position. Developed by the United States Coast and Geodetic Survey in 1923 and 1924 for use in accurately fixing the position of survey ships during hydrographic survey operations, it was the first navigation technique in human history other than dead reckoning that did not require visual observation of a landmark, marker, light, or celestial body, and the first non-visual means to provide precise positions. First employed operationally in 1924, radio acoustic ranging remained in use until 1944, when new radio navigation techniques developed during World War II rendered it obsolete.
Technique
To fix their position using radio acoustic ranging, a ship's crew first ascertained the temperature and salinity of sea water in the vicinity of the ship to determine an accurate velocity of sound through the water. The crew then threw a small TNT bomb off the ship's stern. It exploded at a depth of about , and a chronograph aboard the ship automatically recorded the time the explosion was heard at the ship. The sound traveled outward from the explosion, eventually reaching hydrophones at known locations – shore stations, anchored station ships, or moored buoys – at a distance from the ship. Each hydrophone was connected to a radio transmitter that automatically sent a signal indicating the time its hydrophone detected the sound. At the distances involved – generally less than – each of these radio signals arrived at the ship at essentially the same instant that each of the remote hydrophones detected the sound of |
https://en.wikipedia.org/wiki/Charles%20F.%20Roos | Charles Frederick Roos (May 18, 1901 – January 6, 1958) was an American economist who made contributions to mathematical economics. He was one of the founders of the Econometric Society together with American economist Irving Fisher and Norwegian economist Ragnar Frisch in 1930. He served as Secretary-Treasurer during the first year of the Society and was elected as President in 1948. He was director of research of the Cowles Commission from September 1934 to January 1937.
Roos earned a PhD in mathematics from Rice University in 1926, under supervision of Griffith C. Evans. He was amongst the first, together with Evans and mathematician Frank P. Ramsey, to use the calculus of variations in mathematical economics. His direct involvement with two key institutions in economic history, both the Econometric Society and the Cowles Commission, place him in a pivotal position in the mathematization of economics in the first half of the 20th century. His own work, however, would not be so influential. Mathematical economics and econometrics eventually favored technical and epistemological approaches that were different from his own.
Biography
Charles Frederick Roos was born in New Orleans, Louisiana on 18 May 1901. He studied mathematics at the Rice Institute, receiving his Bachelor of Arts degree in 1921, his Master of Arts degree in 1924, and, being awarded his PhD in 1926. His main interests were in the calculus of variations, integral equations, and the applications of these to economic theory. His early research was deeply inspired by the work of his thesis advisor Griffith C. Evans who used these same mathematical tools to analyze business cycles, economic equilibrium, and economic competition. During the following years, from 1926 to 1928, Roos continued his academic studies as National Research Fellow at the University of Chicago and Princeton University.
At Princeton, Roos met the Norwegian economist Ragnar Frisch who was travelling there under a grant from the |
https://en.wikipedia.org/wiki/Accelerated%20Mobile%20Pages | AMP (originally an acronym for Accelerated Mobile Pages) is an open source HTML framework developed by the AMP Open Source Project. It was originally created by Google as a competitor to Facebook Instant Articles and Apple News. AMP is optimized for mobile web browsing and intended to help webpages load faster. AMP pages may be cached by a CDN, such as Microsoft Bing or Cloudflare's AMP caches, which allows pages to be served more quickly.
AMP was first announced on October 7, 2015. After a technical preview period, AMP pages began appearing in Google mobile search results in February 2016. AMP has been criticized for potentially giving further control over the web to Google and other concerns. The AMP Project announced it would move to an open governance model on September 18, 2018 and is part of the OpenJS Foundation as of October 10, 2019.
History
Announcement and launch
The AMP Project was announced by Google on October 7, 2015, following discussions with its partners in the Digital News Initiative (DNI), and other news publishers and technology companies around the world, about improving the performance of the mobile web. More than 30 news publishers and several technology companies (including Twitter, Pinterest, LinkedIn and WordPress) were initially announced as collaborators in the AMP Project.
AMP pages first appeared to web users in February 2016, when Google began to show the AMP versions of webpages in mobile search results. Initially links to AMP pages were restricted to a "Top Stories" section of Google's mobile search results; by September 2016 Google started linking to AMP content in the main mobile search results area. At the time, Google search distinguished AMP links with an icon.
According to one of the co-founders of the AMP Project, Malte Ubl, AMP was originally called PCU, which stood for Portable Content Unit.
Growth and expansion
In September 2016, Microsoft announced support for AMP in the Bing apps for iOS and Android.
In February |
https://en.wikipedia.org/wiki/Segregated%20Runge%E2%80%93Kutta%20methods | The Segregated Runge–Kutta (SRK) method is a family of IMplicit–EXplicit (IMEX) Runge–Kutta methods that were developed to approximate the solution of differential algebraic equations (DAE) of index 2.
The SRK method were motivated as a numerical method for the time integration of the incompressible Navier–Stokes equations with two salient properties. First, velocity and pressure computations are segregated. Second, the method keeps the same order of accuracy for both velocities and pressures. However, the SRK method can also be applied to any other DAE of index 2.
The Segregated Runge–Kutta method
Consider an index 2 DAE defined as follows:
where , , and
In the previous equations is known as the differential variable, while is known as the algebraic variable. The time derivative of the differential variable, , depends on itself, , on the algebraic variable, , and on the time, . The second equation can be seen as a constraint on differential variable, .
Let us take the time derivative of the second equation. Assuming that the function is linear and does not depend on time, and that the function is linear with respect to , we have that
A Runge–Kutta time integration scheme is defined as a multistage integration in which each stage is computed as a combination of the unknowns evaluated in other stages. Depending on the definition of the parameters, this combination can lead to an implicit scheme or an explicit scheme. Implicit and explicit schemes can be combined, leading to IMEX schemes.
Suppose that the function can be split into two operators and such that
where and are the terms to be treated implicitly and explicitly, respectively.
The SRK method is based on the use of IMEX Runge–Kutta schemes and can be defined by the following scheme:
Given a time step size , at a time ,
for each Runge-Kutta stage , with , solve:
1)
2) .
Update the variables at solving:
3)
4) .
References
Equations |
https://en.wikipedia.org/wiki/Buzi%20%28fortification%29 | Buzi are small forts built along the northern frontier of China. They are prevalent in the Loess Plateau of Shaanxi, Gansu and Ningxia provinces, usually square or oval (as hill forts) and built out of rammed earth walls. The forts are built on hilltops, at strategic locations or within villages. A large number of forts are found in Tianshui (over 500) and Dingxi prefectures, totalling over 1400 forts. One of the densest concentration of forts is Tongwei County, which has the nickname "thousand forts county" (). Qin'an County is home to three larger castles.
Although each fort may not be impressive on its own, the combined defense line of forts has been compared to the Great Wall of China.
Usage
Although some of the forts date back to the Qin dynasty, they have been used as late as the Sino-Japanese war. During the Dungan Revolt, villagers sought refuge from the raiding and fighting in these forts, and new forts were even constructed with the same methods. As of now, most of the forts lie abandoned, partly due to the difficulty of reaching the hilltops. The courtyards of some forts have filled by farmhouses or Taoist temples.
The defenders inside the forts varied, with some larger forts being permanently manned by trained military, smaller ones were just refuge places for villagers from nearby.
References
Fortification lines
Chinese architectural history
Military history of China
Forts in China
Buildings and structures in Gansu |
https://en.wikipedia.org/wiki/Digital%20enclosure | Digital enclosure is a model of interrogating the relationship that has arisen between surveillance and the new emerging interactive economy developed by Mark Andrejevic, an associate professor at the University of Iowa. The new interactivity-enhanced spaces born of the new digital era has created "digital enclosures" in both a physical and virtual sense. It is this enclosure that allows for individuals or companies to own, operate, and claim ownership over the information generated by the users who interact within their boundaries.
Andrejevic cites the example of Google and Earthlink to provide the city of San Francisco with free wireless access within the city in multiple articles. This project was to be funded through "contextual advertising", the use of custom-targeted ads developed by tracking the location of users throughout the day. This potentially opens the door for google to create custom algorithms to gain information on users from search engine inquiries, map requests, and even Gmail accounts.
Companies who invest in such information from enclosures due to their potentially profit contributes to what Andrejevic describes as "the work of being watched", individuals who unknowingly or willingly submit to giving up their information that generates such economic value in exchange for use of digital commodities.
Andrejevic connects this idea back to the forcible separation of workers from the means of production – a process defined by Marx as "primitive" accumulation. Marx developed this from the first agrarian enclosure of land, where works were separated from the land in order to force workers to regain access to be contractually regulated.
The model of digital enclosures is necessary to understanding new information commodities being valuable resources in the new era of digital capitalism. The private ownership of such enclosures aims to separate users from the means of interaction, transaction, communication, and expression, much like the farmer's se |
https://en.wikipedia.org/wiki/Multidimensional%20empirical%20mode%20decomposition | In signal processing, multidimensional empirical mode decomposition (multidimensional EMD) is an extension of the one-dimensional (1-D) EMD algorithm to a signal encompassing multiple dimensions. The Hilbert–Huang empirical mode decomposition (EMD) process decomposes a signal into intrinsic mode functions combined with the Hilbert spectral analysis, known as the Hilbert–Huang transform (HHT). The multidimensional EMD extends the 1-D EMD algorithm into multiple-dimensional signals. This decomposition can be applied to image processing, audio signal processing, and various other multidimensional signals.
Motivation
Multidimensional empirical mode decomposition is a popular method because of its applications in many fields, such as texture analysis, financial applications, image processing, ocean engineering, seismic research, etc. Several methods of Empirical Mode Decomposition have been used to analyze characterization of multidimensional signals.
Introduction to empirical mode decomposition (EMD)
The empirical mode decomposition (EMD) method can extract global structure and deal with fractal-like signals.
The EMD method was developed so that data can be examined in an adaptive time–frequency–amplitude space for nonlinear and non-stationary signals.
The EMD method decomposes the input signal into several intrinsic mode functions (IMF) and a residue. The given equation will be as follows:
where is the multi-component signal. is the intrinsic mode function, and represents the residue corresponding to intrinsic modes.
Ensemble empirical mode decomposition
The ensemble mean is an approach to improving the accuracy of measurements. Data is collected by separate observations, each of which contains different noise over an ensemble of universes. To generalize this ensemble idea, noise is introduced to the single data set, , as if separate observations were indeed being made as an analogue to a physical experiment that could be repeated many times. The added w |
https://en.wikipedia.org/wiki/Cross%20ventilation | Cross ventilation is a natural phenomenon where wind, fresh air or a breeze enters upon an opening, such as a window, and flows directly through the space and exits through an opening on the opposite side of the building (where the air pressure is lower). This produces a cool stream of air and as well as a current across the room from the exposed area to the sheltered area. Other terms used for the effect include, cross-breeze, cross-draft, wind effect ventilation and cross-flow ventilation.
Windows or vents positioned on opposite sides of the room allow passive breezes a pathway through the structure, which circulate the air and provide passive cooling. Cross ventilation is a wind-driven effect and requires no energy, in addition to being the most effective method of wind ventilation. A commonly used technique to remove pollutants and heat in an indoor environment, cross ventilation can also decrease or even obviate the need for an air-conditioner and can improve indoor air quality.
Process
The phenomenon occurs when openings in an environment (including vehicles) or building (houses, factories, sheds, etc) are set on opposite or adjoining walls, which allow air to enter and exit, thus creating a current of air across the interior environment. There is also a pressure difference between the opposite sides of the establishment. The effect is mostly driven by the wind, whereby the air is pulled into the building on the high pressure windward part and is pushed out on the low pressure downwind side of the establishment (because of the pressure difference between the openings). A wind's effect on a structure creates regions that have positive pressure on the building's upwind area and a negative pressure on the downwind side. Thus, the building shape and local wind patterns are critical in making wind pressures that force airflow through its openings.
If the windows on both sides of the buildings are opened, the overpressure on the side facing the wind, and/or lo |
https://en.wikipedia.org/wiki/Verifi | Verifi is a payment protection and management firm founded in 2005. It is based in Los Angeles, California, and has close to 9000 verified accounts. It was acquired by Visa Inc. in 2019 for an undisclosed sum.
History
Matthew Katz, Verifi’s founder and CEO, started the company after developing a customized solution that systematically identifies multiple types of payment risk. Katz initially started a successful business while still in college and saw subsequent success as an entrepreneur, having founded and partnered several other businesses and consulting firms. Mr. Katz is a graduate of Washington University in St. Louis with a degree in Economics.
Process
The company’s primary product offering is Cardholder Dispute Resolution Network (CDRN), which helps connect financial organizations and merchants, allowing merchants to act in real time to issue refunds, work to clear up equivocal transaction histories, or initiate traditional chargeback procedures.
In April 2017, Verifi launched Order Insight, a collaboration platform that connects cardholders, merchants and issuers to resolve billing confusion and disputes in real time. Through the platform, order details are made available to consumers via their card issuer. If a consumer elects to contact the issuing bank, their call center or back office personnel have access to the same order details and compelling evidence.
Industries
Verifi works within most retail-related industries, with omni-channel and e-commerce merchants, and maximizes "payment yield" across the entire transaction life-cycle.
References
External links
Official Website
Payment service providers
Online payments
Credit cards in the United States
Companies based in Los Angeles
Financial services companies established in 2005
Financial services companies of the United States |
https://en.wikipedia.org/wiki/Proof%20of%20space | Proof of space (PoS) is a type of consensus algorithm achieved by demonstrating one's legitimate interest in a service (such as sending an email) by allocating a non-trivial amount of memory or disk space to solve a challenge presented by the service provider. The concept was formulated in 2013 by Dziembowski et al. and (with a different formulation) by Ateniese et al..
Proofs of space are very similar to proofs of work (PoW), except that instead of computation, storage is used to earn cryptocurrency. Proof-of-space is different from memory-hard functions in that the bottleneck is not in the number of memory access events, but in the amount of memory required.
After the release of Bitcoin, alternatives to its PoW mining mechanism were researched, and PoS was studied in the context of cryptocurrencies. Proofs of space are seen as a fairer and greener alternative by blockchain enthusiasts due to the general-purpose nature of storage and the lower energy cost required by storage.
In 2014, Signum (formerly Burstcoin) became the first practical implementation of a PoS (initially as proof of capacity) blockchain technology and is still actively developed. Other than Signum, several theoretical and practical implementations of PoS have been released and discussed, such as SpaceMint and Chia, but some were criticized for increasing demand and shortening the life of storage devices due to greater disc reading requirements than Signum.
Concept description
A proof-of-space is a piece of data that a prover sends to a verifier to prove that the prover has reserved a certain amount of space. For practicality, the verification process needs to be efficient, namely, consume a small amount of space and time. For security, it should be hard for the prover to pass the verification if it does not actually reserve the claimed amount of space.
One way of implementing PoS is by using hard-to-pebble graphs. The verifier asks the prover to build a labeling of a hard-to-pebble graph. Th |
https://en.wikipedia.org/wiki/Sergey%20Pavlovich | Sergey Alexandrovich Pavlovich (also known as Police Dog, panther[757], Fallen Angel, diplomaticos) is one of the most famous carders on the territory of the former Soviet Union.
Biography
Born 22 February 1983 in Vyazye, a village in Mogilev region of Belarus. In 2000 finished School No 124 in Minsk. In 2000–2003 was studying on the faculty of Journalism of Belarusian State University. In 2004–2009 was brought to trial three times on account of cyber crimes. The total sentence amounted to 16 years in jail. While being in jail, Sergey wrote and published a book:
How to Steal A Million: The Memoirs of a Russian Hacker
in which he convinced young men not to follow in his criminal steps. All of the honorarium for the book the author donated to a Children's Oncologic Clinic of Borovlyany (Belarus).
Criminal activities
Sergey started his criminal career with contributing to Russia's largest carding forum CarderPlanet.
Among Sergey's friends and e.f.g. partners in crime were such people as BadB (Vladislav Khorokhorin), Fidel (Sergey Storchak), Maksik (Maksim Yastremskiy), JonnyHell (Alexander Suvorov) and a Chinese Triad boss Michael Cheung Ho and others.
In 2008 Sergey appeared among the 11 people charged with "the largest personal data theft in the history of the USA". An associate of the famous hacker Albert Gonzalez.
Currently he is an entrepreneur (4 businesses on the Internet), the author of the popular YouTube channels "People PRO" and "Mother Russia", acts as a speaker on cybersecurity and promotion on YouTube.
References
1983 births
Carding (fraud)
Living people |
https://en.wikipedia.org/wiki/Gradient-enhanced%20kriging | Gradient-enhanced kriging (GEK) is a surrogate modeling technique used in engineering. A surrogate model (alternatively known as a metamodel, response surface or emulator) is a prediction of the output of an expensive computer code.
This prediction is based on a small number of evaluations of the expensive computer code.
Introduction
Adjoint solvers are now becoming available in a range of computational fluid dynamics (CFD) solvers, such as Fluent, OpenFOAM, SU2 and US3D. Originally developed for optimization, adjoint solvers are now finding more and more use in uncertainty quantification.
Linear speedup
An adjoint solver allows one to compute the gradient of the quantity of interest with respect to all design parameters at the cost of one additional solve. This, potentially, leads to a linear speedup: the computational cost of constructing an accurate surrogate decrease, and the resulting computational speedup scales linearly with the number of design parameters.
The reasoning behind this linear speedup is straightforward. Assume we run primal solves and adjoint solves, at a total cost of . This results in data; values for the quantity of interest and partial derivatives in each of the gradients. Now assume that each partial derivative provides as much information for our surrogate as a single primal solve. Then, the total cost of getting the same amount of information from primal solves only is . The speedup is the ratio of these costs:
A linear speedup has been demonstrated for a fluid-structure interaction problem and for a transonic airfoil.
Noise
One issue with adjoint-based gradients in CFD is that they can be particularly noisy.
When derived in a Bayesian framework, GEK allows one to incorporate not only the gradient information, but also the uncertainty in that gradient information.
Approach
When using GEK one takes the following steps:
Create a design of experiment (DoE): The DoE or 'sampling plan' is a list of different location |
https://en.wikipedia.org/wiki/ET-188 | ET-188 was an IBM PC XT compatible computer made by the Yugoslav company Novkabel (Novosadska fabrika kabela - Novi Sad Cable Factory) from Novi Sad (now Serbia) in the 1980s.
Novkabel already had experience in developing computer systems (ERA 20, ERA 60 and others) which was used to make ET-188 as an original design, compatible with IBM PC XT.
To save space and to lower the cost, ET-188 used 8 MHz Intel 80188 CPU, with integrated timer, DMA and interrupt controller. This also made it faster than the original XT.
ET-188 was offered to the public in 1985 and advertised in the Yugoslav computer press.
An improved ET-188A model was in May 1986 presented to the public at the Belgrade International Fair of Technique and Technical Advancements with more RAM and a new redesigned case.
Among other things, ET-188A was used for education in classrooms throughout Vojvodina province.
Technical specifications
CPU: Intel 80188 running at 8 MHz
ROM: 8 KB custom made BIOS
RAM: 256KB (ET-188) or 512 KB (ET-188A), expandable up to 640 KB
Operating system: MS-DOS 3.20
Secondary storage: 2 x 5.25’’ 360KB floppy drive or 5.25’’ 360KB floppy drive + 22MB Tandon hard disk
Display: CGA or Hercules compatible adapter
Sound: beeper
I/O ports: DE9 video output, RS-232, parallel port, keyboard
References
IBM PC compatibles |
https://en.wikipedia.org/wiki/Dragon%20kiln | A dragon kiln () or "climbing kiln", is a traditional Chinese form of kiln, used for Chinese ceramics, especially in southern China. It is long and thin, and relies on having a fairly steep slope, typically between 10° and 16°, up which the kiln runs. The kiln could achieve the very high temperatures, sometimes as high as 1400 °C, necessary for high-fired wares including stoneware and porcelain, which long challenged European potters, and some examples were very large, up to 60 metres long, allowing up to 25,000 pieces to be fired at a time. By the early 12th century CE they might be over 135 metres long, allowing still larger quantities to be fired; more than 100,000 have been claimed.
History
According to recent excavations in Shangyu District in the northeast of Zhejiang province and elsewhere, the origins of the dragon kiln may go back as far as the Shang dynasty (c. 1600 to 1046 BCE), and is linked to the introduction of stoneware, fired at 1200 °C or more. These kilns were much smaller than later examples, at some 5–12 metres long, and also sloped far less.
The type had certainly developed by the Warring States period, and by the Eastern Wu kingdom (220–280 CE), there were over 60 kilns at Shangyu. Thereafter it remained the main design used in southern China until the Ming dynasty. The pottery areas of south China are mostly hilly, whereas those on the plains of north China typically lack suitable slopes; here the mantou kiln type predominated.
The Nanfeng Kiln in Guangdong province is several centuries old and still functioning. It was a producer of Shiwan ware as well as architectural ceramics, and today also functions as a tourist attraction.
Characteristics
The kilns were normally made of brick, and are one type of "cross-draught" kilns, where the flames travel more or less horizontally, rather than up from or down to the floor. The firing time could be relatively short, meaning about 24 hours for a small kiln. Early kilns were rising tunnels, not |
https://en.wikipedia.org/wiki/Trellis-Owl | Trellis Owl (alternately, Trellis or Trellis-Owl) is a defunct object-oriented programming language created by Digital Equipment Corporation. A programming environment, just called Trellis, was also produced.
References
Programming languages |
https://en.wikipedia.org/wiki/Haggis%20%28programming%20language%29 | Haggis is a high-level reference programming language used primarily to examine computing science for Scottish pupils taking SQA courses on the subject. Haggis is used as a tool to bridge the gap between pseudocode and typical computer programming.
Haggis is not based on any one language but a mixture that is intended to allow a pupil familiar with any of the many languages used in classrooms to easily understand the syntactic construct being used in an example. It has multiple programming paradigms of functional, imperative and object-oriented to suit this purpose.
There are three separate language definitions, one for each level at which computing is assessed by the SQA; these are proper subsets of each other, so for example any program contained by the National 5 level language is also well-defined at Higher and Advanced Higher levels. Higher includes the definition of procedures and functions and the use of record types and files, while Advanced Higher includes object-orientation.
Online Haggis interpreters have been developed to provide a way for examiners and teachers to check their programs are correctly defined and behave as expected.
Overview
In Scotland, school-level computing qualifications are awarded by the Scottish Qualifications Authority. A decision was made for computing courses that a single choice of programming language for examination should not be mandated: this allows teachers to choose languages as appropriate to context. This however leaves the issue of how to examine programming, especially in the light of recent educational research which encourages the teaching of reading and understanding code as a core discipline, which should therefore be examined.
Initially, a form of pseudocode language emerged among examiners, to avoid any such language dependency. However this led to the very undesirable situation that, while students are being taught about the importance of rigour of terms in a programming language, they can look back over p |
https://en.wikipedia.org/wiki/Arabic%20Speech%20Corpus | The Arabic Speech Corpus is a Modern Standard Arabic (MSA) speech corpus for speech synthesis. The corpus contains phonetic and orthographic transcriptions of more than 3.7 hours of MSA speech aligned with recorded speech on the phoneme level. The annotations include word stress marks on the individual phonemes.
The Arabic Speech Corpus was built as part of a doctoral project by Nawar Halabi at the University of Southampton funded by MicroLinkPC who own an exclusive license to commercialise the corpus, but the corpus is available for strictly non-commercial purposes through the official Arabic Speech Corpus website. It is distributed under the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Purpose
The corpus was mainly built for speech synthesis purposes, specifically Speech Synthesis, but the corpus has been used for building HMM based voices in Arabic. It was also used to automatically align other speech corpora with their phonetic transcript and could be used as part of a larger corpus for training speech recognition systems.
Contents
The package contains the following:
1813 .wav files containing spoken utterances.
1813 .lab files containing text utterances.
1813 .TextGrid files containing the phoneme labels with time stamps of the boundaries where these occur in the .wav files.
phonetic-transcript.txt which has the form "[wav_filename]" "[Phoneme Sequence]" in every line.
orthographic-transcript.txt which has the form "[wav_filename]" "[Orthographic Transcript]" in every line. Orthography is in Buckwalter Format which is friendlier where there is software that does not read Arabic script. It can be easily converted back to Arabic.
There is an extra 18 minutes of fully annotated corpus (separate from above but with the same structure as above) which was used to evaluated the corpus (see PhD thesis).
The corpus was also used to prove that using automatically extracted, orthography-based stress marks improve the quality o |
https://en.wikipedia.org/wiki/Aruba%20S.p.A. | Aruba S.p.A is an Italian company mainly active in the Web hosting and domain registration businesses. It is the market leader in Italy, and also has a large market share in the Czech Republic and Slovakia.
References
External links
Technology companies established in 1994
Internet technology companies of Italy
Domain name registrars
Web hosting |
https://en.wikipedia.org/wiki/Maskin%20monotonicity | Maskin monotonicity is a desired property of voting systems, suggested by Eric Maskin.
Each voter reports his entire preference relation over the set of alternatives. The set of reports is called a preference profile. A social choice rule maps the preference profile to the selected alternative.
For a preference profile with a chosen alternative , there is another preference profile such that the position of relative to each of the other alternatives either improves or stays the same as in . With Maskin monotonicity, should still be chosen at .
Maskin monotonicity is a necessary condition for implementability in Nash equilibrium. Moreover, any social choice rule that satisfies Maskin monotonicity and another property called "no veto power" can be implemented in Nash equilibrium form if there are three or more voters.
See also
Monotonicity (mechanism design)
The monotonicity criterion in voting systems
References
Mechanism design
Voting |
https://en.wikipedia.org/wiki/Tesla%20Automation | Tesla Automation GmbH (formerly Grohmann Engineering GmbH) is a German engineering automation company based in Prüm in the state of Rhineland-Palatinate. The company operates a development center in Neutraubling, Bavaria, as well as support offices in Chandler, Arizona, and Shanghai, China. The company was founded in 1983 by Klaus Grohmann and acquired by Tesla, Inc., in January 2017. Klaus Grohmann was ousted after clashing with Tesla CEO Elon Musk.
The product portfolio includes machinery for the production of microprocessors and memory chips, airbag sensors and power steering controllers, as well as systems for the production of car door and roof seals, lithium-ion battery cells and modules. Among other things, the company manufactures robotics that are used in the production of batteries and electronics.
The firm works closely with universities within dual track studies of Mechanical Engineering and Robotic Process Automation. In addition, it provides training in the field of Technical Product Design, Industrial Mechanics, CNC Operation, Construction Technology, IT, Mechatronics and Industrial Electronic Technology.
History
Grohmann Engineering was founded by Klaus Grohmann in 1963. It moved its headquarters to Prüm in 1983.
In November 2016, the privately held company agreed to be acquired by the American automotive company Tesla Motors. At the time, 74.9% of the company was owned by Klaus Grohmann and 25.1% was owned by the . At the time, the company had 700 employees, with annual revenues of about €120 million. The deal was completed on 3 January 2017, at which point the company employed 800 people. According to a May 2017 SEC filing, Tesla paid $109.5 million in cash for the company, and in addition paid $25.8 million for a new incentive compensation agreement.
In April 2017, founder Klaus Grohmann left the company due to a dispute with Tesla CEO Elon Musk. Musk demanded the company halt production for competitors, such as BMW and Daimler AG, to focus |
https://en.wikipedia.org/wiki/Class-XD%20Amplifier | Class XD (crossover displacement) is a proprietary and patented amplifier technology developed in-house by Cambridge Audio.
First appearing in 2006 in the Azur 840A integrated amplifier, the Crossover Displacement design sought to combine the performance of a traditional Class A design with the efficiency of Class B but without the linearity and distortion limitations of Class AB.
In Class A amplification the output transistors are modulated by the audio signal to turn more or less ‘on’ but never actually turn off. However, in Class B the output transistors actually at some point turn off as the output is passed from one transistor to another.
In the point at which the output moves from one transistor to another (the crossover point), a small amount of distortion is created. "This crossover distortion is inevitable and although it can be minimized, Cambridge's Class XD alternative doesn't eliminate crossover distortion, it shifts it away from the zero-crossing point of the waveform."
Amplifier technology
Class A
Class A amplifiers avoid crossover distortion (because the transistors are always on) but at the expense generating a lot of heat. Managing this heat and power dissipation means that Class A designs can be expensive to implement and of lower power output to minimize heat build-up.
Class B
Class B amplifiers inherently generate crossover distortion and display this non-linearity at the zero-crossing, where the crossover distortion is in evidence no matter how low the signal amplitude. At one unique value of quiescent current, the distortion produced is a minimum, and this is what characterizes optimal Class B.
Class XD
It would be much more desirable for some to have an amplifier that would give Class A performance up to the transition level, with Class B after that, rather than AB. This would abolish the AB gain changes that cause extra distortion.
This is the basic Class XD principle, to develop a topology that displaces the crossover point to on |
https://en.wikipedia.org/wiki/Andela | Andela is a global job placement network for software developers. Andela focuses on sustainable careers, connecting technologists with long-term engagements, access to international roles, competitive compensation, and career coaching through the Andela Learning Community.
History
Andela was founded in 2014 by Jeremy Johnson, Iyinoluwa Aboyeji, Nadayar Enegesi, Brice Nkengsa, Ian Carnevale, and Christina Sass. In May 2014, Andela launched their first recruitment cycle in Lagos by putting their first call for applications on Twitter. The company hired their first cohort—four Nigerian software engineers—after receiving 700 applications for 4 spots.
In 2018, Andela celebrated the first two sets of engineers to complete the four-year program.
In 2019, Christina Sass stepped down from her full-time role as President and transitioned into a supporting role as the Chair of the Andela Advisory Council and the Andela Alumni Group. Of the six original founders, Jeremy Johnson continues to work at Andela.
While the initial route for engineers to join the company was via the Andela Fellowship, a four-year program geared towards junior engineers, this changed in 2019. Andela widened its hiring criteria for mid and senior-level engineers in Lagos, Nairobi, and Kampala. After their first remote expansions to Ghana and Egypt, the entire organization went fully remote in 2020.
As of 2021, Andela provides technologists from six continents to access opportunities with global companies on long-term embedded contracts. Andela’s applicants can undertake training in software languages such as Ruby on Rails, JavaScript, Python, Ruby, React Native, Node, PHP, and more.
Funding
On June 25, 2015, Andela secured $10 million in Series A funding. Spark Capital led the investment and many of the Seed investors participated.
The following year, The Chan Zuckerberg Initiative—founded and owned by Facebook founder Mark Zuckerberg and Priscilla Chan—led in Andela’s $24 million Series |
https://en.wikipedia.org/wiki/Multiplicative%20weight%20update%20method | The multiplicative weights update method is an algorithmic technique most commonly used for decision making and prediction, and also widely deployed in game theory and algorithm design. The simplest use case is the problem of prediction from expert advice, in which a decision maker needs to iteratively decide on an expert whose advice to follow. The method assigns initial weights to the experts (usually identical initial weights), and updates these weights multiplicatively and iteratively according to the feedback of how well an expert performed: reducing it in case of poor performance, and increasing it otherwise. It was discovered repeatedly in very diverse fields such as machine learning (AdaBoost, Winnow, Hedge), optimization (solving linear programs), theoretical computer science (devising fast algorithm for LPs and SDPs), and game theory.
Name
"Multiplicative weights" implies the iterative rule used in algorithms derived from the multiplicative weight update method. It is given with different names in the different fields where it was discovered or rediscovered.
History and background
The earliest known version of this technique was in an algorithm named "fictitious play" which was proposed in game theory in the early 1950s. Grigoriadis and Khachiyan applied a randomized variant of "fictitious play" to solve two-player zero-sum games efficiently using the multiplicative weights algorithm. In this case, player allocates higher weight to the actions that had a better outcome and choose his strategy relying on these weights. In machine learning, Littlestone applied the earliest form of the multiplicative weights update rule in his famous winnow algorithm, which is similar to Minsky and Papert's earlier perceptron learning algorithm. Later, he generalized the winnow algorithm to weighted majority algorithm. Freund and Schapire followed his steps and generalized the winnow algorithm in the form of hedge algorithm.
The multiplicative weights algorithm is also wid |
https://en.wikipedia.org/wiki/Stormfall%3A%20Age%20of%20War | Stormfall: Age of War is a social browser game created in 2012 by Plarium and then moved to Facebook in November. This game franchise builds on the success of Plarium's earlier Facebook titles in the crowded web-based PvP strategy game market, though a pay-to-win aspect of the game raises concerns.
Plarium, which has a global registered player base of 250 million players, introduced Stormfall: Rise of Balur as the sequel to the hugely popular Stormfall: Age of War.
Gameplay
Stormfall: Age of War challenges players to fortify an army and castle within the fictional Kingdom of Darkshine.
Players are required to employ strategy skills to build castles, manage resources, and participate in player-versus-player warfare under the guidance of Lord Oberon, protector of Stormfall. The game has a top-down isometric camera angle and retro style 2D graphics. Players' military units can raid enemy bases, defend their own base, and be used to participate in group warfare in a league system.
Reception
The game became one of the twenty fastest-growing games on Facebook globally, according to Julien Codorniou, Facebook's head of European platform partnerships in 2013. Pete Davison of Adweek called Stormfall "a very solid addition to the growing lineup of mid-core strategy titles on the social network" (referring to Facebook), and wrote that it "features solid gameplay, reasonable (if slightly inconsistent) presentation and plenty of things to do."
References
External links
Stormfall: Age of War - on Plarium.com
Facebook games
2012 video games
Browser games
Online games
Free-to-play video games
Massively multiplayer online real-time strategy games
Video games scored by Jesper Kyd
Video games developed in Israel
Plarium games |
https://en.wikipedia.org/wiki/Bubble-net%20feeding | Bubble-net feeding is a feeding behavior engaged in by humpback whales and Bryde's whales. It is one of the few surface feeding behaviors that humpback whales are known to engage in. This type of feeding can be done alone or in groups with as many as twenty whales participating at once. Whales can also perform a similar method of surface feeding called "lunge feeding".
Humpback whales are migratory and only eat during half of the year. During this feeding season humpback whales actively feed for up to twenty-two hours a day. They do this so they can store enough fat reserves to live through their breeding season when they do not eat at all. Humpback whales typically spend summer months in feeding grounds with cooler waters that they return to every year. They have been documented feeding in areas such as Southeast Alaska and off the coast of Antarctica.
Method
Bubble-net feeding is a cooperative feeding method used by groups of humpback whales. This behavior is not instinctual, it is learned; not every population of humpbacks knows how to bubble net feed. Humpback whales use vocalizations to coordinate and efficiently execute the bubble net so they all can feed. As the group circles a school of small fish such as salmon, krill, or herring, they use a team effort to disorient and corral the fish into a "net" of bubbles. One whale will typically begin to exhale out of their blowhole at the school of fish to begin the process. More whales will then blow bubbles while continuing to circle their prey. The size of the net created can range from in diameter. One whale will sound a feeding call, at which point all whales simultaneously swim upwards with mouths open to feed on the trapped fish. As the whales swim up to the surface to feed they can hold up to 15,000 gallons of sea water in their mouths. Humpback whales have 14 to 35 throat grooves that run from the top of the chin all the way down to the navel. These grooves allow the mouth to expand. When they swallow th |
https://en.wikipedia.org/wiki/Ley%20Org%C3%A1nica%20de%20Protecci%C3%B3n%20de%20Datos%20de%20Car%C3%A1cter%20Personal | The Organic Law 15/1999 of December 13 on Protection of Personal Data (, LOPD) was Spanish organic law that guaranteed and protected the processing of personal data, public liberties, and fundamental human rights, and especially of personal and family honor and privacy. It was approved by the General Court on December 13, 1999. This law was developed based on Article 18 of the Spanish Constitution of 1978, the familiar and personal right to privacy, and the secrecy of communications.
Its main objective was to regulate the treatment of data and files, of a personal nature, regardless of the support in which they are treated, the rights of citizens over them and the obligations of those who create or treat them. This law affected all data that referred to registered humans on any support, computer or otherwise. Excluded from this regulation are those data collected for domestic use, classified materials of the state and those files that collected data on Terrorism and other forms of organized crime (not simple delinquency).
Based on this law, the Spanish Agency for Data Protection was created, at the state level, which ensures compliance with this Law.
This act was repealed by the passage of a new data protection act, the Organic Law 3/2018 of December 5, about protection of personal data and guarantees of digital rights, to conform the Spanish legislation with the General Data Protection Regulation
Regulatory development
The Royal Decree 994/1999 on Security Measures for automated files that containing personal data of June 11, 1999 (RMS): It is a regulation that develops the Organic Law 5/1992, of October 29, of Regulation of the Automated Treatment of Personal Data (LORTAD), regulates the technical and organizational measures that must be applied to the information systems in which personal data are processed in an automated way. (Repealed since April 19 of 2010)
The Royal Decree 1720/2007, of December 21 on the development of the Organic Law on Data Protect |
https://en.wikipedia.org/wiki/ClickHouse | ClickHouse is an open-source column-oriented DBMS (columnar database management system) for online analytical processing (OLAP) that allows users to generate analytical reports using SQL queries in real-time. ClickHouse Inc. is headquartered in the San Francisco Bay Area with the subsidiary, ClickHouse B.V., based in Amsterdam, Netherlands.
In September 2021 in San Francisco, CA, ClickHouse incorporated to house the open source technology with an initial $50 million investment from Index Ventures and Benchmark Capital with participation by Yandex N.V. and others. On October 28, 2021 the company received Series B funding totaling $250 million at an valuation of $2 billion from Coatue Management, Altimeter Capital, and other investors. The company continues to build the open source project and engineering cloud technology.
History
ClickHouse’s technology was first developed over 10 years ago at Yandex, Russia's largest technology company. In 2009, Alexey Milovidov and developers started an experimental project to check the hypothesis if it was viable to generate analytical reports in real-time from non-aggregated data that is also constantly added in real-time. The developers spent 3 years to prove this hypothesis, and in 2012 ClickHouse launched in production for the first time to power Yandex.Metrica, the second-largest web analytics platform in the world, after Google Analytics.
Unlike custom data structures used before, ClickHouse was applicable more generally to work as a database management system. The power and utility of ClickHouse offered a true column-oriented DBMS, it allowed for systems to generate reports from petabytes of raw data with sub-second latencies. ClickHouse was widely adopted at Yandex including for Yandex.Tank load testing tool and Yandex.Market to monitor site accessibility and KPIs.
In 2016, the ClickHouse project was released as open-source software under the Apache 2 license in June 2016 to power analytical use cases around the globe |
https://en.wikipedia.org/wiki/Cannabis%20in%20South%20Africa | Cannabis in South Africa has been decriminalized for personal adult consumption in private by the Constitutional Court of South Africa. However, laws still prohibit its use outside of one's private dwelling as well as the buying and selling of cannabis. Regulations prohibiting the purchase of cannabis-containing products remain in effect, raising questions about the enforceability of the ruling.
Prior to the lifting of the prohibition of cannabis in 2018, advocates pressured the government to amend laws restricting cannabis that were first established in 1922 to allow exceptions for medical use, religious practices, and other purposes. The Afrikaans term commonly used to refer to cannabis is dagga (), derived from the Khoikhoi word , which was adopted by early European colonial settlers in the Dutch Cape Colony.
Cannabis is believed to have been introduced to Africa by early Arab or Indian traders. It was already in widespread use among South Africa's indigenous Khoisan and Bantu peoples before European settlement in the Cape in 1652. Additionally, it was traditionally utilized by Basotho communities to facilitate childbirth. According to author Hazel Crampton, historical Afrikaner recipes for teas and foods incorporated the use of cannabis. The plant's use was primarily associated with traditional African populations and individuals of lower economic status.
Long-term research conducted by the Medical Research Council (MRC) indicates that the number of cannabis users in South Africa was 2.2 million in 2004, which increased to 3.2 million by 2008. In 2003, Interpol ranked South Africa as the world's fourth-largest cannabis producer, and the Institute for Security Studies reported that a significant portion of cannabis seized in the United Kingdom, and a third seized globally, originated from South Africa.
History
The first written record of the plant in South Africa is by Jan van Riebeeck, who ordered officers of the Voorman to purchase "daccha" in Natal for tra |
https://en.wikipedia.org/wiki/Bernoulli%27s%20triangle | Bernoulli's triangle is an array of partial sums of the binomial coefficients. For any non-negative integer n and for any integer k included between 0 and n, the component in row n and column k is given by:
i.e., the sum of the first k nth-order binomial coefficients. The first rows of Bernoulli's triangle are:
Similarly to Pascal's triangle, each component of Bernoulli's triangle is the sum of two components of the previous row, except for the last number of each row, which is double the last number of the previous row. For example, if denotes the component in row n and column k, then:
Sequences derived from the Bernoulli triangle
As in Pascal's triangle and other similarly constructed triangles, sums of components along diagonal paths in Bernoulli's triangle result in the Fibonacci numbers.
As the third column of Bernoulli's triangle (k = 2) is a triangular number plus one, it forms the lazy caterer's sequence for n cuts, where n ≥ 2. The fourth column (k = 3) is the three-dimensional analogue, known as the cake numbers, for n cuts, where n ≥ 3.
The fifth column (k = 4) gives the maximum number of regions in the problem of dividing a circle into areas for n + 1 points, where n ≥ 4.
In general, the (k + 1)th column gives the maximum number of regions in k-dimensional space formed by hyperplanes, for n ≥ k. It also gives the number of compositions (ordered partitions) of n + 1 into k + 1 or fewer parts.
References
External links
The sequence of numbers formed by Bernoulli's triangle on the On-Line Encyclopedia of Integer Sequences: https://oeis.org/A008949.
Factorial and binomial topics
Triangles of numbers |
https://en.wikipedia.org/wiki/Video%20Display%20Corporation | Video Display Corp. is a Tucker, Georgia manufacturer of digital projector display units, and a manufacturer and distributor of cathode ray tubes used in data display screens.
History
Video Display was founded in 1975 by Ronald Ordway, who has remained chairman and CEO since that time. He is also the company's largest single shareholder.
Products and Markets
Video Display's largest business segment involves designing and manufacturing digital projector display units for defense contractors, including Boeing and Lockheed Martin, for use in flight simulation and training. Video Display also makes the display units for the industrial and medical industry sectors. Its digital projector display unit operations are located at Cape Canaveral, Fla.
Video Display also manufactures and distributes cathode ray tubes for video display terminals. Its AYON Cyber Security subsidiary, located in Palm Bay, Florida manufactures video displays for the defense industry, security and monitoring industry and other sectors.
References
External links
Video Display Corp. website
Companies based in Tucker, Georgia
Defense companies of the United States
Electronics companies established in 1975
Display technology companies
Electronics companies of the United States
1975 establishments in Georgia (U.S. state) |
https://en.wikipedia.org/wiki/List%20of%20digital%20therapeutics%20companies | This is a list of companies in digital therapeutics, a healthcare discipline that utilizes digital and Internet-based health technologies to make behavioral and lifestyle changes in patients. Digital therapeutics is a relatively new discipline that uses digital implements like mobile devices, apps, sensors, the Internet of Things, and others to spur behavioral changes in patients. The methodology operates as both a preventative technique for at-risk patients and a treatment for patients with existing conditions. The companies in this list are organized by the health conditions or functions on which they focus.
Companies
Diabetes, obesity, and heart disease
Glooko produces a software for diabetes patients that also uses Internet-connected insulin pumps and blood glucose meters to collect data.
Omada Health produces a program called "Prevent" that provides patients with health coaching, support groups, and education for preventing type 2 diabetes, heart disease, and obesity.
Fitness
MyFitnessPal
Digital Physical Therapy
Sword Health
References
Health information technology companies
Medical lists |
https://en.wikipedia.org/wiki/Gosi%20Khurd%20Irrigation%20Project | GosiKhurd Irrigation Project also known as Indira Sagar Irrigation Project is one of the major irrigation projects in Godavari basin in Indian state Maharashtra in the Bhandara district on the river Wainganga. The project was launched in 7th Five Year Plan by former Prime Minister Rajiv Gandhi during 1984. It has been declared as National Irrigation Project by Government of India.
The project involved, Gose Khurd Dam along with the network of water canals including 99 km long right bank canal, 22.93 km left bank canal, lifting stations at Akot, Ambhora, Mokharbardi, Nerla and Tekepar. The project also included renovation of Asolamendha dam on river Pathari. The project is aimed to irrigate 2.5 lakh hectares of land. The project is designed to provide an annual irrigation to an area of 89,856 ha in Bhandara district, 19,481 ha in Nagpur district and 1,41,463 ha in Chandrapur district.
Project timelines
The project was accepted by the technical advisory committee in 1988 with an estimated cost of INR 461.19 Crores at the 1981–82 price level. The project got approval by the Forest and Environment department in 1988. The project was approved by Planning Commission of India in 1995. The updated cost of the project was INR 7777.85 Crores at 2007–08 prices that were approved by Planning Commission. The project was getting funds under Accelerated Irrigation Benefits Program (AIBP) since 1996. In 2009 it was declared as a National Project. Till 2009 19179 hectares of irrigation potential was created while remaining will be created as a national project.
Project affected people started receiving compensations promised by Chief Minister Pruthviraj Chavan in 2013.
Project hurdles and criticism
A major criticism of the project involved environmental damage and damage to local livelihood. Around 92 villages were affected by this project making total PAP (Project affected people) of more than 1 lakh. Organization of the project affected inhabitants was formed named Gosikh |
https://en.wikipedia.org/wiki/ExtraTorrent | ExtraTorrent (commonly abbreviated ET) was an online index of digital content of entertainment media and software. Until its shut down it was among the top 5 BitTorrent indexes in the world, where visitors could search, download and contribute magnet links and torrent files, which facilitate peer-to-peer file sharing among users of the BitTorrent protocol.
History
ExtraTorrent was founded in 2006 by the administrator who acted under the alias "SaM".
In November 2016, the website celebrated its 10-year anniversary. The website briefly changed their logo with a celebratory theme and launched a contest for users to guess the most downloaded movies on the site in exchange for prizes.
Shutdown
On 17 May 2017, ExtraTorrent voluntarily ceased operations out of the blue. The entire website was replaced with a message from the administrator, stating that the website was to shut down permanently (as well as all mirror domains), and wipe all data relating to the website and its content. The website was already down for days due to an emergency maintenance situation, just two days before the website shut down permanently.
At the time of its shutdown, ExtraTorrent's primary domain name was the 291st most viewed website globally, according to statistics from Alexa Internet.
Clones
Shortly after the shutdown of the official ExtraTorrent website, multiple clones and imitations appeared online. Initially, the most popular one of these clones was located at extratorrent.cd. While this was at first speculated to be an official rehosting, it was later discovered to be a re-skinned of The Pirate Bay, serving exact information from their database, under an ExtraTorrent interface. Despite this however, the website still quickly gained a large userbase, reaching two million unique visitors in May 2017. To date, there are no new "official" ExtraTorrent mirrors as the database for the original was wiped during its shutdown in 2017. The site was blocked in Spain in 2019, with the bloc |
https://en.wikipedia.org/wiki/GlTF | glTF (Graphics Library Transmission Format or GL Transmission Format and formerly known as WebGL Transmissions Format or WebGL TF) is a standard file format for three-dimensional scenes and models. A glTF file uses one of two possible file extensions: .gltf (JSON/ASCII) or .glb (binary). Both .gltf and .glb files may reference external binary and texture resources. Alternatively, both formats may be self-contained by directly embedding binary data buffers (as base64-encoded strings in .gltf files or as raw byte arrays in .glb files). An open standard developed and maintained by the Khronos Group, it supports 3D model geometry, appearance, scene graph hierarchy, and animation. It is intended to be a streamlined, interoperable format for the delivery of 3D assets, while minimizing file size and runtime processing by apps. As such, its creators have described it as the "JPEG of 3D."
Overview
The glTF format stores data primarily in JSON. The binary .glb format is still JSON data, but serialized as an efficient binary blob instead of plain text. The JSON may also contain blobs of binary data known as buffers, and refer to external files, for storing mesh data, images, etc.
The fundamental building blocks of a glTF scene are nodes. Nodes are organized into a hierarchy, such that a node may have other nodes defined as children. Nodes may have transforms relative to their parent. Nodes may refer to resources, such as meshes, skins, and cameras. Meshes may refer to materials, which refer to textures, which refer to images. Scenes are defined using an array of root nodes.
Most of the top-level glTF properties use a flat hierarchy for storage. Nodes are saved in an array called "nodes", and are referred to by index, including by other nodes. A glTF scene refers to its root nodes by index. Furthermore, nodes refer to meshes by index, which refer to materials by index, which refer to textures by index, which refer to images by index.
All glTF data structures support being |
https://en.wikipedia.org/wiki/Gc%20%28engineering%29 | {{DISPLAYTITLE:gc (engineering)}}
In engineering and physics, gc is a unit conversion factor used to convert mass to force or vice versa. It is defined as
In unit systems where force is a derived unit, like in SI units, gc is equal to 1. In unit systems where force is a primary unit, like in imperial and US customary measurement systems, gc may or may not equal 1 depending on the units used, and value other than 1 may be required to obtain correct results. For example, in the kinetic energy (KE) formula, if gc = 1 is used, then KE is expressed in foot-poundals; but if gc = 32.174 is used, then KE is expressed in foot-pounds.
Motivations
According to Newton's second law, the force F is proportional to the product of mass m and acceleration a:
or
If F = 1 lbf, m = 1 lb, and a = , then
Leading to
gc is defined as the reciprocal of the constant K
or equivalently, as
Specific systems of units
References
Equations |
https://en.wikipedia.org/wiki/Two-dimensional%20window%20design | Windowing is a process where an index-limited sequence has its maximum energy concentrated in a finite frequency interval. This can be extended to an N-dimension where the N-D window has the limited support and maximum concentration of energy in a separable or non-separable N-D passband. The design of an N-dimensional window particularly a 2-D window finds applications in various fields such as spectral estimation of multidimensional signals, design of circularly symmetric and quadrantally symmetric non-recursive 2D filters, design of optimal convolution functions, image enhancement so as to reduce the effects of data-dependent processing artifacts, optical apodization and antenna array design.
Two-dimensional window
Due to the various applications of multi-dimensional signal processing, the various design methodologies of 2-D windows is of critical importance in order to facilitate these applications mentioned above, respectively.
Consider a two-dimensional window function (or window array) with its Fourier transform denoted by . Let and denote the impulse and frequency response of an ideal filter and and denote the impulse and frequency response of a filter approximating the ideal filter, then we can approximate by . Since has an infinite extent it can be approximated as a finite impulse response by multiplying with a window function as shown below
and in the Fourier domain
The problem is to choose a window function with an appropriate shape such that is close to and in any region surrounding a discontinuity of , shouldn't contain excessive ripples due to the windowing.
2-D window function from 1-D function
There are four approaches for generating 2-D windows using a one-dimensional window as a prototype.
Approach I
One of the methods of deriving the 2-D window is from the outer product of two 1-D windows, i.e., The property of separability is exploited in this approach. The window formed has a square region of support and is separabl |
https://en.wikipedia.org/wiki/Budgie%20%28desktop%20environment%29 | Budgie is an independent, free and open-source desktop environment for Linux and other Unix-like operating systems that targets the desktop metaphor. Budgie is developed by the Buddies of Budgie organization, which is composed of a team of contributors from Linux distributions such as Fedora, Debian, and Arch Linux. Its design emphasizes simplicity, minimalism, and elegance, while providing the means to extend or customize the desktop in various ways. Unlike desktop environments like Cinnamon, Budgie does not have a reference platform, and all distributions that ship Budgie are recommended to set defaults that best fit their desired user experience.
History
Budgie was created by Ikey Doherty as the default desktop environment for his new Linux distribution, EvolveOS, which was eventually renamed to Solus. The intention was to use GNOME components to create a more lightweight and traditional desktop that still had most of the features that GNOME provided at the time. Development was announced on , with the first public version being released soon after on .
Budgie would see a flurry of releases in 2015, culminating in version 10 being released in December of that year, a full rewrite of the codebase in the Vala programming language. The desktop would soon spread to distributions other than Solus, with SparkyLinux and Manjaro adopting the desktop environment in 2015. Arch Linux, Ubuntu, and Void Linux would follow in 2016, with a dedicated "remix" edition for Ubuntu being created, eventually renamed to Ubuntu Budgie when it was adopted by Canonical as an official flavor.
Doherty would make his last commit to the repository on . Later, on , it was announced that Doherty had ceased communication with the rest of the Solus team for unknown reasons, leaving Solus (and thus Budgie) without a lead developer. Joshua Strobl, one of the members of the newly formed Solus core team and an already active contributor to Budgie, would take up the responsibility of continuing |
https://en.wikipedia.org/wiki/General%20der%20Nachrichtenaufkl%C3%A4rung | General der Nachrichtenaufklärung was the signals intelligence agency of the Heer (German Army), before and during World War II. It was the successor to the former cipher bureau known as Inspectorate 7/VI in operation between 1940 and 1942, when it was further reorganised into the Headquarters for Signal Intelligence () (abbr. LNA) between 1942 and 1944, until it was finally reorganised in October 1944 into the GdNA. The agency was also known at the OKH/Gend Na, GendNa or Inspectorate 7 or more commonly OKH/GdNA. Inspectorate 7/VI was also known as In 7 or In/7 or In 7/VI and also OKH/Chi.
Chi-Stelle
The letter "Chi" for the Chiffrierabteilung ("cipher department") is, contrary to what one might expect, not the Greek letter Chi, nor anything to do with the chi-squared test, a common cryptographic test used as part of deciphering of enciphered message, and invented by Solomon Kullback, but simply the first three letters of the word Chiffrierabteilung.
Background
Key personnel
Senior personnel
General der Nachrichtentruppe Erich Fellgiebel, was Director of the Code and Cipher section of the Defense Ministry from 1931 to 1932 and held the dual combined office of Chef HNW and Chief Signal Officer Armed Forces (Chef WNF) from 1939 until 20 July 1944. Fellgiebel was executed in July 1944 after an attempt on Hitler's life in the failed 20th July plot.
The unit was then subordinated to Generalleutnant Fritz Thiele, who was Director of Section III of the Armed Forces Signal Communication Group, Radio Defense Corps, or more accurately the AgWBNV, Radio Communication Group 3 (), (AgWNV/FU III) were responsible for locating, eliminating, or neutralizing all enemy agents' radio activities.
Generalleutnant Wilhelm Gimmler, () was Chief Signals Officer subordinated to Commander in Chief OB West and Chief of the Armed Forces Signal Communications Office. Gimmler was responsible for coordinating all the cryptographic security studies undertaken by German Armed Forces and was |
https://en.wikipedia.org/wiki/Hexagonal%20fast%20Fourier%20transform | The fast Fourier transform (FFT) is an important tool in the fields of image and signal processing. The hexagonal fast Fourier transform (HFFT) uses existing FFT routines to compute the discrete Fourier transform (DFT) of images that have been captured with hexagonal sampling. The hexagonal grid serves as the optimal sampling lattice for isotropically band-limited two-dimensional signals and has a sampling efficiency which is 13.4% greater than the sampling efficiency obtained from rectangular sampling. Several other advantages of hexagonal sampling include consistent connectivity, higher symmetry, greater angular resolution, and equidistant neighbouring pixels. Sometimes, more than one of these advantages compound together, thereby increasing the efficiency by 50% in terms of computation and storage when compared to rectangular sampling. Despite all of these advantages of hexagonal sampling over rectangular sampling, its application has been limited because of the lack of an efficient coordinate system. However that limitation has been removed with the recent development of the hexagonal efficient coordinate system (HECS, formerly known as array set addressing or ASA) which includes the benefit of a separable Fourier kernel. The existence of a separable Fourier kernel for a hexagonally sampled image allows the use of existing FFT routines to efficiently compute the DFT of such an image.
Preliminaries
Hexagonal Efficient Coordinate System (HECS)
The hexagonal efficient coordinate system (formerly known as array set addressing (ASA)) was developed based on the fact that a hexagonal grid can be represented as a combination of two interleaved rectangular arrays. It is easy to address each individual array using familiar integer-valued row and column indices and the individual arrays are distinguished by a single binary coordinate. Therefore, a full address for any point in the hexagonal grid can be uniquely represented by three coordinates.
where the coordinate |
https://en.wikipedia.org/wiki/Directory-based%20coherence | Directory-based coherence is a mechanism to handle Cache coherence problem in Distributed shared memory (DSM) a.k.a. Non-Uniform Memory Access (NUMA). Another popular way is to use a special type of computer bus between all the nodes as a "shared bus" (a.k.a. System bus). Directory-based coherence uses a special directory to serve instead of the shared bus in the bus-based coherence protocols. Both of these designs use the corresponding medium (i.e. directory or bus) as a tool to facilitate the communication between different nodes, and to guarantee that the coherence protocol is working properly along all the communicating nodes. In directory based cache coherence, this is done by using this directory to keep track of the status of all cache blocks, the status of each block includes in which cache coherence "state" that block is, and which nodes are sharing that block at that time, which can be used to eliminate the need to broadcast all the signals to all nodes, and only send it to the nodes that are interested in this single block.
Following are a few advantages and disadvantages of the directory based cache coherence protocol:
Scalability: This is one of the strongest motivations for going to directory based designs. What we mean by scalability, in short, is how good a specific system is in handling the growing amount of work that it is responsible to do . For this criteria, Bus based systems cannot do well due to the limitation caused when having a shared bus that all nodes are using in the same time. For a relatively small number of nodes, bus systems can do well. However, while the number of nodes is growing, some problems may occur in this regard. Especially since only one node is allowed to use the bus at a time, which will significantly harm the performance of the overall system. On the other hand, using directory-based systems, there will be no such bottleneck to constrain the scalability of the system.
Simplicity: This is one of the points where the |
https://en.wikipedia.org/wiki/Dependent%20component%20analysis | Dependent component analysis (DCA) is a blind signal separation (BSS) method and an extension of Independent component analysis (ICA). ICA is the separating of mixed signals to individual signals without knowing anything about source signals. DCA is used to separate mixed signals into individual sets of signals that are dependent on signals within their own set, without knowing anything about the original signals. DCA can be ICA if all sets of signals only contain a single signal within their own set.
Mathematical representation
For simplicity, assume all individual sets of signals are the same size, k, and total N sets. Building off the basic equations of BSS (seen below) instead of independent source signals, one has independent sets of signals, s(t) = ({s1(t),...,sk(t)},...,{skN-k+1(t)...,skN(t)})T, which are mixed by coefficients A=[aij]εRmxkN that produce a set of mixed signals, x(t)=(x1(t),...,xm(t))T. The signals can be multidimensional.
The following equation BSS separates the set of mixed signals, x(t), by finding and using coefficients, B=[Bij]εRkNxm, to separate and get the set of approximation of the original signals, y(t)=({y1(t),...,yk(t)},...,{ykN-k+1(t)...,ykN(t)})T.
Methods
Sub-Band Decomposition ICA (SDICA) is based on the fact that wideband source signals are dependent, but that other subbands are independent. It uses an adaptive filter by choosing subbands using a minimum of mutual information (MI) to separate mixed signals. After finding subband signals, ICA can be used to reconstruct, based on subband signals, by using ICA. Below is a formula to find MI based on entropy, where H is entropy.
References
Signal processing |
https://en.wikipedia.org/wiki/Slim%20lattice | In lattice theory, a mathematical discipline, a finite lattice is slim if no three join-irreducible elements form an antichain. Every slim lattice is planar. A finite planar semimodular lattice is slim if and only if it contains no cover-preserving diamond sublattice M3 (this is the original definition of a slim lattice due to George Grätzer and Edward Knapp).
Notes
References
Lattice theory |
https://en.wikipedia.org/wiki/WiTrack | A WiTrack is a 3-D motion tracking sensor that is capable of monitoring human body movements. This sensor is able to serve three main purposes, such functions being the following: turning on/off home appliances, tracking a lethal fall, and improving gaming experience. This new piece of technology, currently in its developing stages, was developed primarily by Fadel Adib and Dina Katabi at MIT. The WiTrack functions through the use of radio signals, which help perform the task of finding a person's current location, the radio signals not been affected at all by walls and other physical obstacles present.
Technology
WiTrack functions through the use of radio signals that reflect off a person, this does not require a user to hold on to a wireless device like other previous similar inventions. WiTrack uses a total of four antennas, one antenna is used for transmitting signals and three antennas are used for receiving the signals. Through the use of these antennas, a geometric model is created which is able to calculate the distance between the antennas receiving the signals and the user where the signals derive from.
Time-of-flight estimation
The time it takes for the signal to travel from the transmitter to the person's body, and back again to the transmitter.
3-D localization
Through the use of the antennas, a geometric model is created which is able to calculate the distance between the antennas and the person's body.
Fall detection and pointing
WiTrack classifies a fall as a rapid change on the elevation of a person. WiTrack can track the motion of a person's arm and detect on what direction the arm is pointing at.
Future goals
The WiTrack was well received, this led to the creation of Emerald. Emerald was an extension to the WiTrack's ability to track falls among the elderly. Just like WiTrack, Emerald tracks the motion of a person through the use of radio signals reflected off the person's body. Once a fall is detected it alerts the person taking care of the |
https://en.wikipedia.org/wiki/3D%20sound%20reconstruction | 3D sound reconstruction is the application of reconstruction techniques to 3D sound localization technology. These methods of reconstructing three-dimensional sound are used to recreate sounds to match natural environments and provide spatial cues of the sound source. They also see applications in creating 3D visualizations on a sound field to include physical aspects of sound waves including direction, pressure, and intensity. This technology is used in entertainment to reproduce a live performance through computer speakers. The technology is also used in military applications to determine location of sound sources. Reconstructing sound fields is also applicable to medical imaging to measure points in ultrasound.
Techniques
To reproduce robust and natural-sounding audio from a three-dimensional audio recording, sound localization and reverberation reconstruction techniques are used. These techniques process sound to reproduce the spatial cues.
The location of a sound source is determined through three-dimensional sound localization using multiple microphone arrays, binaural hearing methods, and HRTF (head-related transfer function).
After identifying the direction, other signal processing techniques are used to measure the impulse response over lengths of time to determine the intensity components in different directions. By having both data and combining intensity of sound with direction, a three-dimensional sound field is determined and physical qualities that create the resulting changes in intensity are reconstructed.
As a result of this two-step process, the reconstructed three-dimensional sound field contains information not only on the localization of the sound source, but also on the physical aspects of the environment of the original signal source. This is its difference from the results of the sound localization process.
After the sound is reconstructed and the spatial cues are available, they need to be delivered to the customer. The different met |
https://en.wikipedia.org/wiki/Vector-radix%20FFT%20algorithm | The vector-radix FFT algorithm, is a multidimensional fast Fourier transform (FFT) algorithm, which is a generalization of the ordinary Cooley–Tukey FFT algorithm that divides the transform dimensions by arbitrary radices. It breaks a multidimensional (MD) discrete Fourier transform (DFT) down into successively smaller MD DFTs until, ultimately, only trivial MD DFTs need to be evaluated.
The most common multidimensional FFT algorithm is the row-column algorithm, which means transforming the array first in one index and then in the other, see more in FFT. Then a radix-2 direct 2-D FFT has been developed, and it can eliminate 25% of the multiplies as compared to the conventional row-column approach. And this algorithm has been extended to rectangular arrays and arbitrary radices, which is the general vector-radix algorithm.
Vector-radix FFT algorithm can reduce the number of complex multiplications significantly, compared to row-vector algorithm. For example, for a element matrix (M dimensions, and size N on each dimension), the number of complex multiples of vector-radix FFT algorithm for radix-2 is , meanwhile, for row-column algorithm, it is . And generally, even larger savings in multiplies are obtained when this algorithm is operated on larger radices and on higher dimensional arrays.
Overall, the vector-radix algorithm significantly reduces the structural complexity of the traditional DFT having a better indexing scheme, at the expense of a slight increase in arithmetic operations. So this algorithm is widely used for many applications in engineering, science, and mathematics, for example, implementations in image processing, and high speed FFT processor designing.
2-D DIT case
As with the Cooley–Tukey FFT algorithm, the two dimensional vector-radix FFT is derived by decomposing the regular 2-D DFT into sums of smaller DFT's multiplied by "twiddle" factors.
A decimation-in-time (DIT) algorithm means the decomposition is based on time domain , see more in |
https://en.wikipedia.org/wiki/Multisite%20cloud | A multisite cloud is a cloud composed of several single sites (or data centers), each from the same or different providers and explicitly accessible to cloud users. In the multisite cloud environment, the tasks of a program or a workflow should be scheduled in order to achieve efficient processing.
References
Cloud computing |
https://en.wikipedia.org/wiki/Fake%20news%20website | Fake news websites (also referred to as hoax news websites) are websites on the Internet that deliberately publish fake news—hoaxes, propaganda, and disinformation purporting to be real news—often using social media to drive web traffic and amplify their effect. Unlike news satire, fake news websites deliberately seek to be perceived as legitimate and taken at face value, often for financial or political gain. Such sites have promoted political falsehoods in India, Germany, Indonesia and the Philippines, Sweden, Mexico, Myanmar, and the United States. Many sites originate in, or are promoted by, Russia, North Macedonia, and Romania, among others. Some media analysts have seen them as a threat to democracy. In 2016, the European Parliament's Committee on Foreign Affairs passed a resolution warning that the Russian government was using "pseudo-news agencies" and Internet trolls as disinformation propaganda to weaken confidence in democratic values.
In 2015, the Swedish Security Service, Sweden's national security agency, issued a report concluding Russia was using fake news to inflame "splits in society" through the proliferation of propaganda. Sweden's Ministry of Defence tasked its Civil Contingencies Agency with combating fake news from Russia. Fraudulent news affected politics in Indonesia and the Philippines, where there was simultaneously widespread usage of social media and limited resources to check the veracity of political claims. German Chancellor Angela Merkel warned of the societal impact of "fake sites, bots, trolls".
Fraudulent articles spread through social media during the 2016 U.S. presidential election, and several officials within the U.S. Intelligence Community said that Russia was engaged in spreading fake news. Computer security company FireEye concluded that Russia used social media to spread fake news stories as part of a cyberwarfare campaign. Google and Facebook banned fake sites from using online advertising. Facebook launched a partners |
https://en.wikipedia.org/wiki/Bibliography%20of%20British%20and%20Irish%20History | The Bibliography of British and Irish History (BBIH) is an electronic bibliography of British and Irish history.
The bibliography covers the Roman period up to the present day including relations with the British Empire and Commonwealth. It is published electronically and was developed from the printed Royal Historical Society Bibliography of British and Irish History. It is usually updated three times per year (February, June and October) and contained just over 600,000 entries by January 2019. It is managed by Brepols Publishers in association with the Royal Historical Society and the Institute of Historical Research. The initial academic editor was Dr Ian Archer of Oxford University; he was succeeded in 2011 by Professor Stephen Taylor of Durham University and he was succeeded in turn by Professor Roey Sweet of the University of Leicester in 2018.
References
External links
Archer, Ian W. Bibliographies of British history
Leaflet for the Bibliography of British and Irish History from Brepols.
Bibliographies of history
Historiography of Ireland
Historiography of the United Kingdom
Online databases |
https://en.wikipedia.org/wiki/SYCL | SYCL is a higher-level programming model to improve programming productivity on various hardware accelerators. It is a single-source embedded domain-specific language (eDSL) based on pure C++17. It is a standard developed by Khronos Group, announced in March 2014.
Origin of the name
SYCL (pronounced ‘sickle’) originally stood for SYstem-wide Compute Language, but since 2020 SYCL developers have stated that SYCL is a name and have made clear that it is no longer an acronym and contains no reference to OpenCL.
Purpose
SYCL is a royalty-free, cross-platform abstraction layer that builds on the underlying concepts, portability and efficiency inspired by OpenCL that enables code for heterogeneous processors to be written in a “single-source” style using completely standard C++. SYCL enables single-source development where C++ template functions can contain both host and device code to construct complex algorithms that use hardware accelerators, and then re-use them throughout their source code on different types of data.
While the SYCL standard started as the higher-level programming model sub-group of the OpenCL working group and was originally developed for use with OpenCL and SPIR, SYCL is a Khronos Group workgroup independent from the OpenCL working group since September 20, 2019 and starting with SYCL 2020, SYCL has been generalized as a more general heterogeneous framework able to target other systems. This is now possible with the concept of a generic backend to target any acceleration API while enabling full interoperability with the target API, like using existing native libraries to reach the maximum performance along with simplifying the programming effort. For example, the Open SYCL implementation targets ROCm and CUDA via AMD's cross-vendor HIP.
Versions
SYCL was introduced at GDC in March 2014 with
provisional version 1.2, then the SYCL 1.2 final version was
introduced at IWOCL 2015 in May 2015.
The latest version for the previous SYCL 1.2.1 series is |
https://en.wikipedia.org/wiki/Multidimensional%20signal%20restoration | In multidimensional signal processing, Multidimensional signal restoration refers to the problem of estimating the original input signal from observations of the distorted or noise contaminated version of the original signal using some prior information about the input signal and /or the distortion process. Multidimensional signal processing systems such as audio, image and video processing systems often receive as input, signals that undergo distortions like blurring, band-limiting etc. during signal acquisition or transmission and it may be vital to recover the original signal for further filtering. Multidimensional signal restoration is an inverse problem, where only the distorted signal is observed and some information about the distortion process and/or input signal properties is known. A general class of iterative methods have been developed for the multidimensional restoration problem with successful applications to multidimensional deconvolution, signal extrapolation and denoising.
Definition
In general, the multidimensional signal restoration problem can be represented by an equation of the form,
where represents the observed m-dimensional distorted output signal, represents the m-dimensional undistorted input signal and represents the distortion operator acting upon the input signal. can be used to model a wide range of transformations such as blurring, additive noise, time limiting, band limiting etc. of multidimensional signals.
A simple straightforward solution to above equation is of the form,
where is the inverse distortion operator.
However, in most cases of practical use, it may be extremely difficult to implement the inverse distortion operator or the such an inverse distortion operator may not exist and even in situations where the distortion operator is known and its inverse can be approximately implemented, the resultant reconstructed signal can have very large reconstruction errors due to the inaccuracies present in the estimation |
https://en.wikipedia.org/wiki/Azoic%20hypothesis | The Azoic hypothesis (sometimes referred to as the Abyssus theory) is a superseded scientific theory proposed by Edward Forbes in 1843, stating that the abundance and variety of marine life decreased with increasing depth and, by extrapolation of his own measurements, Forbes calculated that marine life would cease to exist below .
Overview
The theory was based upon Forbes' findings aboard , a survey ship to which he had been appointed naturalist by the ship's commander Captain Thomas Graves. With Forbes aboard, HMS Beacon set sail around the Aegean Sea on 17 April 1841, from Malta. It was at this point that Forbes began to take dredging samples at various depths of the ocean, he observed that samples from greater depths displayed a narrower diversity of creatures which were generally smaller in size.
Forbes reported his findings from the Aegean Sea in his 1843 report to the British Association entitled Report on the Mollusca and Radiata of the Aegean Sea. His findings were widely accepted by the scientific community and were bolstered by other scientific figures of the time. David Page (1814–1879), a respected geologist, reinforced the theory by stating that "according to experiment, water at the depth of 1000 feet is compressed th of its own bulk; and at this rate of compression we know that at great depths animal and vegetable life as known to us cannot possibly exist – the extreme depressions of seas being thus, like the extreme elevations of the land, barren and lifeless solitudes."
The theory was not disproven until the late 1860s when biologist Michael Sars, Professor of Zoology at Christiania (now Oslo) University, discovered life at a depth greater than 300 fathoms. Sars listed 427 animal species which had been found along the Norwegian coast at a depth of 450 fathoms, and gave a description of a crinoid Rhizocrinus lofotensis which his son had recovered from a depth of 300 fathoms in Lofoten.
In 1869, Charles Wyville Thomson dredged marine life from a de |
https://en.wikipedia.org/wiki/Russian%20AI%20Cup | Russian AI Cup is the annual championship on programming of an artificial intelligence organized by Mail.Ru Group and My.com.
The Russian AI Cup is carried out in the form of a game for descriptive reasons, clearness and simplicity. Briefly, participants create an algorithm that describes a game strategy. The resulting bot is fighting with other similar. The best of them wins the round. Thus, from a series of rounds the tournament which will take place in several stages will be organized.
On the one side, the main mechanics of a game is quite simple that it allows to write really minimum working strategy in a couple of hours. On another side — in game turned out a lot of nuances. To think over to sharpen strategy, rising up standings, it is possible indefinitely. In 2016 the contest is focused on the MOBA game CodeWizards.
2015 contest "CodeRacing"
In the 2015 contest, contestants must make an artificial intelligence to control a car on the squared-tile tracks. The rules are similar to the Rock n' Roll Racing game.
2016 contest "CodeWizards"
In the 2016 contest, contestants must make an artificial intelligence (strategy) to control a wizard in a special game world. The contest rules are based on a popular computer game genre MOBA. In each game players will confront 5 strategies of other players. At the same time, they will have 4 allies. Each five strategies make a faction: Academy or Renegades. The main goal of the faction is to destroy an opposing faction's base. The main personal goal of each wizard is to gain maximal possible number of points. The winner of the game, as well as other places, is determined by the gained score. A player is given points when his wizard deals damage, destroys or is just hanging nearby during death of opposite faction's unit, as well as for some other actions. Each player of a faction is given a significant number of points in case of reaching the main faction goal.
The championship runs from 26 November until 18 December. Wi |
https://en.wikipedia.org/wiki/Volume%20and%20displacement%20indicators%20for%20an%20architectural%20structure | The volume (W) and displacement (Δ) indicators have been discovered by Philippe Samyn in 1997 to help the search for the optimal geometry of architectural structures.
Objective
The study is limited to the quest of the geometry giving the structure of minimum volume.
The cost of a structure depends on the nature and the quantity of the materials used as well as the tools and human resources required for its production.
Although technological progress has reduced the cost of tools and the amount of human resources required, and despite the fact that computerised calculation tools can now be used to determine the dimension of a structure so that the load it bears at every point is within the admissible limits allowed by its constituent materials, it is also necessary for its geometry to be optimal. It is far from simple to find this optimal point because the choice available is so vast.
Furthermore, the resistance of the structure is not the only criterion to take into account. In many cases, it is also important to ensure that it will not undergo excessive deformation under static loads or that it does not vibrate to inconvenient or dangerous levels when subjected to dynamic loads.
Volume and displacement indicators, W and Δ, discovered by Philippe Samyn in August 1997, are useful tools in this regard. This approach does not take into account phenomena of elastic instability. It can indeed be shown that it is always possible to design a structure so that this effect becomes negligible.
The indicators
The objective is to ascertain the optimal morphology for a two-dimensional structure with constant thickness, which:
fits in a rectangle of pre-determined dimensions, longitudinal L and horizontal H, expressed in metres (m);
is made of one (or several) material(s) with a modulus of elasticity E, expressed in Pascals (Pa), and bearing a load at all points within its allowable stress(es) σ, expressed in Pascals (Pa);
is resistant to the maximum loads to which i |
https://en.wikipedia.org/wiki/Convergence%20group | In mathematics, a convergence group or a discrete convergence group is a group acting by homeomorphisms on a compact metrizable space in a way that generalizes the properties of the action of Kleinian group by Möbius transformations on the ideal boundary of the hyperbolic 3-space .
The notion of a convergence group was introduced by Gehring and Martin (1987) and has since found wide applications in geometric topology, quasiconformal analysis, and geometric group theory.
Formal definition
Let be a group acting by homeomorphisms on a compact metrizable space . This action is called a convergence action or a discrete convergence action (and then is called a convergence group or a discrete convergence group for this action) if for every infinite distinct sequence of elements there exist a subsequence and points such that the maps converge uniformly on compact subsets to the constant map sending to . Here converging uniformly on compact subsets means that for every open neighborhood of in and every compact there exists an index such that for every . Note that the "poles" associated with the subsequence are not required to be distinct.
Reformulation in terms of the action on distinct triples
The above definition of convergence group admits a useful equivalent reformulation in terms of the action of on the "space of distinct triples" of .
For a set denote , where . The set is called the "space of distinct triples" for .
Then the following equivalence is known to hold:
Let be a group acting by homeomorphisms on a compact metrizable space with at least two points. Then this action is a discrete convergence action if and only if the induced action of on is properly discontinuous.
Examples
The action of a Kleinian group on by Möbius transformations is a convergence group action.
The action of a word-hyperbolic group by translations on its ideal boundary is a convergence group action.
The action of a relatively hyperbolic group by |
https://en.wikipedia.org/wiki/Moser%E2%80%93de%20Bruijn%20sequence | In number theory, the Moser–de Bruijn sequence is an integer sequence named after Leo Moser and Nicolaas Govert de Bruijn, consisting of the sums of distinct powers of 4. Equivalently, they are the numbers whose binary representations are nonzero only in even positions.
The Moser–de Bruijn numbers in this sequence grow in proportion to the square numbers. They are the squares for a modified form of arithmetic without carrying. The difference of two Moser–de Bruijn numbers, multiplied by two, is never square. Every natural number can be formed in a unique way as the sum of a Moser–de Bruijn number and twice a Moser–de Bruijn number. This representation as a sum defines a one-to-one correspondence between integers and pairs of integers, listed in order of their positions on a Z-order curve.
The Moser–de Bruijn sequence can be used to construct pairs of transcendental numbers that are multiplicative inverses of each other and both have simple decimal representations. A simple recurrence relation allows values of the Moser–de Bruijn sequence to be calculated from earlier values, and can be used to prove that the Moser–de Bruijn sequence is a 2-regular sequence.
Definition and examples
The numbers in the Moser–de Bruijn sequence are formed by adding distinct powers of four. The sequence lists these numbers in sorted order; it begins
For instance, 69 belongs to this sequence because it equals 64 + 4 + 1, a sum of three distinct powers of 4.
Another definition of the Moser–de Bruijn sequence is that it is the ordered sequence of numbers whose binary representation has nonzero digits only in the even positions. For instance, 69 belongs to the sequence, because its binary representation 10001012 has nonzero digits in the positions for 26, 22, and 20, all of which have even exponents. The numbers in the sequence can also be described as the numbers whose base-4 representation uses only the digits 0 or 1. For a number in this sequence, the base-4 representation can be fou |
https://en.wikipedia.org/wiki/Sociome | The Sociome is a concept used by scientists in Biology and Sociology referring to the dimensions of existence that are social. The term is also an indication of the convergence of systems biology and the study of society as a complex system that has begun to occur among early 21st Century scientists. Just as the phenome is typically thought of as the set of expressed phenotypes of an organism, the sociome can be thought of as the set of observed characteristics of societies. For example, while all societies consisting of humans might be thought of as having the potential to become egalitarian social democracies, not all observed societies are egalitarian or social democracies. Thus, the sociome can also be thought of indirectly as an ideal type of the unrealized potential of any given organization of social beings.
Origin of term
The first known usage of the term sociome was in 2001 by Daichi Kamiyama. The term has also been utilized by sociologist Adam Thomas Perzynski. The two scientists differ in their usage. Kamiyama's study describes a new scientific "era of the sociome (Sociology[+ome])" characterized by the study of the social activities of molecules. This usage is an anthropomorphism of social behavior, wherein molecules are described as having the ability to socialize. Perzynski's social scientific usage varies from this considerably. While Sociology is the study of society, behavior and social relationships, the sociome is the characterization and quantification of patterns, variables, activities, relationships and attributes across all societies that exist and can be studied. The suffix -ome has been used primarily in biology, as in genome, proteome, microbiome, metabolome and phenome. Basu and colleagues have used the term sociome to refer to a sort of standardized approach to the characterization of geocoded social attributes (e.g. neighborhood level). In 2014, Del Savio and colleagues discussed the blurring of the boundaries between disciplines, and |
https://en.wikipedia.org/wiki/Weighted%20planar%20stochastic%20lattice | Physicists often use various lattices to apply their favorite models in them. For instance, the most favorite lattice is perhaps the square lattice. There are 14 Bravais space lattice where every cell has exactly the same number of nearest, next nearest, nearest of next nearest etc. neighbors and hence they are called regular lattice. Often physicists and mathematicians study phenomena which require disordered lattice where each cell do not have exactly the same number of neighbors rather the number of neighbors can vary wildly. For instance, if one wants to study the spread of disease, viruses, rumors etc. then the last thing one would look for is the square lattice. In such cases a disordered lattice is necessary. One way of constructing a disordered lattice is by doing the following.
Starting with a square, say of unit area, and dividing randomly at each step only one block, after
picking it preferentially with respect to ares, into four smaller blocks creates weighted planar stochastic lattice (WPSL). Essentially it is a disordered planar lattice as its block size and their coordination number are random.
Description
In applied mathematics, a weighted planar stochastic lattice (WPSL) is a structure that has properties in common with those of lattices and those of graphs. In general, space-filling planar cellular structures can be useful in a wide variety of seemingly disparate physical and biological systems.
Examples include grain in polycrystalline structures, cell texture and tissues in biology, acicular texture in martensite growth, tessellated pavement on ocean shores, soap froths
and agricultural land division according to ownership etc. The question of how these structures appear and the understanding of their topological and geometrical properties have always been an interesting proposition among scientists in general and physicists in particular.
Several models prescribe how to generate cellular structures. Often these
structures can mimic directly th |
https://en.wikipedia.org/wiki/Secure%20signature%20creation%20device | A secure signature creation device (SSCD) is a specific type of computer hardware or software that is used in creating an electronic signature. To be put into service as a secure signature creation device, the device must meet the rigorous requirements laid out under Annex II of Regulation (EU) No 910/2014 (eIDAS), where it is referred to as a qualified (electronic) signature creation device (QSCD). Using secure signature creation devices helps in facilitating online business processes that save time and money with transactions made within the public and private sectors.
Description
The minimum requirements that must be met to elevate an electronic signature creation device to the level of a secure signature creation device are provided in Annex II of eIDAS. Through appropriate procedural and technical means, the device must reasonably assure the confidentiality of the data used to create an electronic signature. It further must ensure that the data used to create an electronic signature is unique and only used once. Lastly it shall only allow a qualified trust service provider or certificate authority to create or manage a signatory’s electronic signature data.
To ensure security, signature creation data used by the SSCD to create an electronic signature must provide reasonable protection through current technology to prevent forgery or duplication of the signature. The creation data must remain under the sole control of its signatory to prevent unauthorized use. The SSCD itself is prohibited from altering the signature’s accompanying data.
When a trust service provider or certificate authority places an SSCD into service, they must securely prepare the device according to Annex II of eIDAS in fully compliance to the following three conditions:
While in use or in storage, the SSCD must remain secure.
Further, a reactivation and deactivation of the SSCD must occur under secure conditions.
Any user activation data, include PIN codes be delivered separately from |
https://en.wikipedia.org/wiki/List%20of%20fellows%20of%20the%20AACR%20Academy | The American Association for Cancer Research elects classes of fellows to recognize influential scientists in the field of cancer research.
Six fellows were appointed to Vice President Biden’s Cancer Moonshot Initiative Blue Ribbon Panel. Several are members of the National Academy of Sciences, several have won a Lasker Award, several have won a Nobel Prize, several are HHMI Investigators, and several are past presidents of the AACR.
References
American oncologists
Biology awards |
https://en.wikipedia.org/wiki/Dana%2053 | The Dana/Spicer model 53 is an automotive rear axle produced by Dana-Spicer used in medium to heavy duty truck applications. The Dana/Spicer model 53 (Dana 53) is a semi-float axle that was produced from 1947–1965, both with a 53 differential and wheel ends, and with a Dana 44 differential and Dana 53 wheel ends.
Known vehicles
Jeep Forward Control 170 ('56-'65)
Willys Jeep Truck ('47-'65)
Jeep Pickup ('62-'88)
Lincoln Continental (‘61-‘65)
Notes
Automotive engineering
Automobile axles |
https://en.wikipedia.org/wiki/Matriphagy | Matriphagy is the consumption of the mother by her offspring. The behavior generally takes place within the first few weeks of life and has been documented in some species of insects, nematode worms, pseudoscorpions, and other arachnids as well as in caecilian amphibians.
The specifics of how matriphagy occurs varies among different species. However, the process is best described in the Desert spider, Stegodyphus lineatus, where the mother harbors nutritional resources for her young through food consumption. The mother can regurgitate small portions of food for her growing offspring, but between 1–2 weeks after hatching the progeny capitalize on this food source by eating her alive. Typically, offspring only feed on their biological mother as opposed to other females in the population. In other arachnid species, matriphagy occurs after the ingestion of nutritional eggs known as trophic eggs (e.g. Black lace-weaver Amaurobius ferox, Crab spider Australomisidia ergandros). It involves different techniques for killing the mother, such as transfer of poison via biting and sucking to cause a quick death (e.g. Black lace-weaver) or continuous sucking of the hemolymph, resulting in a more gradual death (e.g. Crab spider). The behavior is less well described but follows a similar pattern in species such as the Hump earwig, pseudoscorpions, and caecilians.
Spiders that engage in matriphagy produce offspring with higher weights, shorter and earlier moulting time, larger body mass at dispersal, and higher survival rates than clutches deprived of matriphagy. In some species, matriphagous offspring were also more successful at capturing large prey items and had a higher survival rate at dispersal. These benefits to offspring outweigh the cost of survival to the mothers and help ensure that her genetic traits are passed to the next generation, thus perpetuating the behavior.
Overall, matriphagy is an extreme form of parental care but is highly related to extended care in the F |
https://en.wikipedia.org/wiki/Shenzhen%20I/O | Shenzhen I/O is a puzzle video game and programming game developed by Zachtronics for Microsoft Windows, Linux, and macOS-based personal computers. The game was released in November 2016.
Gameplay
Shenzhen I/O is a puzzle video game set in the near future in which players assume the role of an electronics engineer who has emigrated to Shenzhen, China to work for fictional technology company Shenzhen Longteng Electronics. The player is tasked with creating products for clients, which involves constructing circuits and then writing code to run them. The programming language used in the game is similar to assembly language and the circuit elements resemble simplified versions of real-world electronics.
The game allows players to create their own challenges by writing Lua scripts.
Development and release
Shenzhen I/O was developed by Zachtronics. The game is seen as a spiritual successor to their previous title TIS-100, a coding puzzle game released in 2015. Shenzhen I/O was designed with the same niche audience in mind, specifically people interested in programming. The idea of using the city of Shenzhen, which is a major electronics and high technology manufacturing center in China, as the setting came from Barth reading blogs from Andrew "bunnie" Huang about his experiences there.
The game features a more approachable user interface than TIS-100 and a cast of characters. Zachtronics was reluctant to include a tutorial to teach players how to play Shenzhen I/O. Instead they opted to include a dense manual containing helpful information. Narrative elements are woven into the manual and gameplay by tasking the player to create fictional products.
Zachtronics announced Shenzhen I/O in September 2016, and released an in-development version of the game via Steam Early Access in October 2016. The game launched out of early access for Linux, macOS, and Windows on November 17, 2016. The release was at the conclusion of about six months of development work.
From players' |
https://en.wikipedia.org/wiki/BMW%20FIZ | The BMW Group Forschungs- und Innovationszentrum (BMW FIZ) is the main engineering and development campus of the BMW Group. It is located in Milbertshofen-Am Hart, a district in northern Munich.
About 20,000 engineers and workers develop cars as well as motorcycles on a 500,000 m2 area spread out across several areas and buildings.
Since October 2017, the BMW FIZ was extended by the BMW Autonomous Driving Campus, located in Unterschleißheim about 13 km north of the main FIZ campus. There, BMW intends to colocate all BMW engineers working on autonomous driving capabilities in the cooperation with Intel.
References
External links
BMW
Milbertshofen-Am Hart
Research institutes in Munich |
https://en.wikipedia.org/wiki/Johnson%27s%20parabolic%20formula | In structural engineering, Johnson's parabolic formula is an empirically based equation for calculating the critical buckling stress of a column. The formula is based on experimental results by J. B. Johnson from around 1900 as an alternative to Euler's critical load formula under low slenderness ratio (the ratio of radius of gyration to effective length) conditions.
The equation interpolates between the yield stress of the material to the critical buckling stress given by Euler's formula relating the slenderness ratio to the stress required to buckle a column.
Buckling refers to a mode of failure in which the structure loses stability. It is caused by a lack of structural stiffness. Placing a load on a long slender bar may cause a buckling failure before the specimen can fail by compression.
Johnson Parabola
Eulers formula for buckling of a slender column gives the critical stress level to cause buckling but doesn't consider material failure modes such as yield which has been shown to lower the critical buckling stress. Johnson's formula interpolates between the yield stress of the column material and the critical stress given by Euler's formula. It creates a new failure border by fitting a parabola to the graph of failure for Euler buckling using
There is a transition point on the graph of the Euler curve, located at the critical slenderness ratio. At slenderness values lower than this point (occurring in specimens with a relatively short length compared to their cross section), the graph will follow the Johnson parabola; in contrast, larger slenderness values will align more closely with the Euler equation.
Euler's formula is
where
critical stress,
critical force,
area of cross section,
Effective length of the rod,
modulus of elasticity,
area moment of inertia of the cross section of the rod,
= slenderness ratio.
Euler's equation is useful in situations such as an ideal pinned-pinned column, or in cases in which the effective length can be used t |
https://en.wikipedia.org/wiki/James%20Ferris | James "Jim" P. Ferris (1932 – March 4, 2016) was an American chemist. He is known for his contributions to the understanding of the origins of life on Earth, specifically by demonstrating a successful mechanism of clay-catalyzed polymerization of RNA, providing further evidence for the RNA World Hypothesis. Additionally, his work in atmospheric photochemistry has illuminated many of the chemical processes which occur in the atmospheres of Jupiter and Saturn's moon, Titan.
Life and career
Jim Ferris was born in Nyack, New York to Richard and Mabel Ferris, the youngest of five children. He completed his undergraduate studies at the University of Pennsylvania and earned a Bachelor of Science in chemistry. He went on to earn a doctorate in natural products chemistry at Indiana University, and continued his post-doctoral studies at the Massachusetts Institute of Technology.
Ferris began his career as a professor at Florida State University, and performed research at the Salk Institute for Biological Studies. He joined the Rensselaer Polytechnic Institute in 1967. He was the editor of Origins of Life and Evolution of Biospheres (OLEB), an academic journal sponsored by The International Society for the Study of the Origin of Life (ISSOL), from 1982 to 1999. He also served as president of ISSOL from 1993 to 1996.
Between 1998 and 2006, he served as director of NASA's New York Center for Studies on the Origins of Life, which would later become the New York Center for Astrobiology at Rensselaer, of which he remained an active member until 2015.
Ferris died on March 4, 2016, at Daughters of Sarah Nursing Center in Albany, New York.
Research
During more than fifty years of research, Ferris made landmark contributions to the field of prebiotic chemistry. His interests in the origins of life led him to explore in detail a diverse array of prebiotic reaction mechanisms, and to make the discovery of clay-directed RNA synthesis. By providing a plausible mechanism for the preb |
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