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https://en.wikipedia.org/wiki/ATRAC%20CD | An ATRAC CD is an optical disc containing compressed digital audio in the ATRAC3 or ATRAC3plus formats, which are part of Sony's ATRAC (Adaptive Transform Acoustic Coding) family of proprietary audio compression algorithms.
Description
ATRAC CD was used with SonicStage Simple Burner software (Ver.1.0 / 1.1) in February 2003, and was subsequently replaced with SonicStage in 2004. The new CD Walkman product was called "ATRAC CD Walkman". In the following year (2004-2005), ATRAC CD boombox was introduced as a new product.
*1 "ATRAC" here refers to the SP mode used in the MD format.
Software for burning ATRAC CD
The ATRAC CD can be burned with SonicStage Simple Burner Ver.1.1, SonicStage 2.x to 3.x and SonicStage CP. This software is able to create a disk image from MP3 files and compact discs, and can be burned with the included CD-R/RW drive on a computer.
See also
Walkman
SonicStage
ATRAC
OpenMG
Hi-MD
References
External links
ATRAC
SONY CD Walkman
Sony products
Compact disc
Digital audio |
https://en.wikipedia.org/wiki/Men%20Going%20Their%20Own%20Way | Men Going Their Own Way (MGTOW ) is an anti-feminist, misogynistic, mostly online community advocating for men to separate themselves from women and a society which they believe has been corrupted by feminism. The community is a part of the manosphere, a collection of anti-feminist websites and online communities that also includes the men's rights movement, incels, and pickup artists.
Like other manosphere communities, MGTOW overlaps with the neoreactionary alt-right movement and has been implicated in online harassment of women. The Southern Poverty Law Center categorizes MGTOW as a part of the male supremacist ideology.
History
While it is not clear where the MGTOW ideology originated, it is believed to have emerged in the early 2000s. A blog called No Ma'am was one of the first sites dedicated to the ideology, publishing a "MGTOW Manifesto" in 2001. Earlier members of MGTOW were largely libertarian. There is a divide between early and contemporary members of MGTOW, with some earlier members expressing derision for the present-day MGTOW community. Online MGTOW forums have included the subreddit r/MGTOW, created in 2011, smaller auxiliary subreddits, and the MGTOW Forum, an independent website that emerged in 2014. Following Reddit's 2017 ban of a large incel subreddit, r/MGTOW was briefly the largest and most active manosphere forum on the site.
According to author Soraya Chemaly, MGTOW and other manosphere communities overlap with various white supremacist, authoritarian, and populist movements worldwide, such as the alt-right which came to prominence around 2015. MGTOW and the alt-right overlap both in membership and in ideology; both believe that feminism has destroyed Western society. Far-right commentator and polemicist Milo Yiannopoulos is credited with helping to popularize MGTOW with a 2014 Breitbart article titled "The Sexodus", in which he described men who were eschewing women, love, sex, and marriage because of feminism.
Researchers have implic |
https://en.wikipedia.org/wiki/Itel%20Mobile | itel Mobile is a China-based mobile phone manufacturer company that was founded by Lei Weiguo and Shenzhen Transsion Holdings Co Limited in March 2014, and is headquartered in Shenzhen, China.
Their products are mainly sold in China and parts of Africa, South Asia, Southeast Asia, Europe and Latin America. It mainly sells low budget smartphones, feature phones and lately, television sets and laptops.
Itel targets a specific part of society (mainly the middle class) that cannot afford the expensive phones available on the market. So they bought low-budget feature phones or smartphones from cheap manufacturing companies, and that's why the company focuses on developing markets.
References
Transsion
Display technology companies
Mobile phone companies of China
Telecommunication equipment companies of China
Mobile phone manufacturers
Hong Kong brands
Manufacturing companies of China
Electronics companies established in 2014
Manufacturing companies established in 2014
Chinese companies established in 2014
2014 establishments in China
Privately held companies of China
Chinese brands |
https://en.wikipedia.org/wiki/Graham%E2%80%93Pollak%20theorem | In graph theory, the Graham–Pollak theorem states that the edges of an -vertex complete graph cannot be partitioned into fewer than complete bipartite graphs. It was first published by Ronald Graham and Henry O. Pollak in two papers in 1971 and 1972 (crediting Hans Witsenhausen for a key lemma), in connection with an application to telephone switching circuitry.
The theorem has since become well known and repeatedly studied and generalized in graph theory, in part because of its elegant proof using techniques from algebraic graph theory. More strongly, write that all proofs are somehow based on linear algebra: "no combinatorial proof for this result is known".
Construction of an optimal partition
A partition into exactly complete bipartite graphs is easy to obtain: just order the vertices, and for each vertex except the last, form a star connecting it to all later vertices in the ordering. Other partitions are also possible.
Proof of optimality
The proof of the Graham–Pollak theorem described by (following ) defines a real variable for each vertex , where denotes the set of all vertices in the graph. Let the left sides and right sides of the th bipartite graph be denoted and , respectively and for any set of vertices define to be the sum of variables for vertices in :
Then, in terms of this notation, the fact that the bipartite graphs partition the edges of the complete graph can be expressed as the equation
Now consider the system of linear equations that sets and for each . Any solution to this system of equations would also obey the nonlinear equations
But a sum of squares of real variables can only be zero if all the individual variables are zero, the trivial solution to the system of linear equations.
If there were fewer than complete bipartite graphs, the system of equations would have fewer than equations in unknowns and would have a nontrivial solution, a contradiction. So the number of complete bipartite graphs must be at least .
Relate |
https://en.wikipedia.org/wiki/HTTP%20parameter%20pollution | HTTP Parameter Pollution (HPP) is a web application vulnerability exploited by injecting encoded query string delimiters in already existing parameters. The vulnerability occurs if user input is not correctly encoded for output by a web application. This vulnerability allows the injection of parameters into web application-created URLs. It was first brought forth to the public in 2009 by Stefano di Paola and Luca Carettoni, in the conference OWASP EU09 Poland. The impact of such vulnerability varies, and it can range from "simple annoyance" to complete disruption of the intended behavior of a web application. Overriding HTTP parameters to alter a web application's behavior, bypassing input and access validation checkpoints, as well as other indirect vulnerabilities, are possible consequences of a HPP attack.
There is no RFC standard on what should be done when it has passed multiple parameters. HPP could be used for cross channel pollution, bypassing CSRF protection and WAF input validation checks.
Behaviour
When they are passed multiple parameters with the same name, here is how various back ends behave.
Types
Client-side
First Order / Reflected HPP
Second Order / Stored HPP
Third Order / DOM HPP
Server-side
Standard HPP
Second Order HPP
Prevention
Proper input validation and awareness about web technology on HPP is protection against HTTP Parameter Pollution.
See also
HTTP response splitting
HTTP request smuggling
References
Hypertext Transfer Protocol
Internet security
Computer security exploits
Bibliography |
https://en.wikipedia.org/wiki/List%20of%20descriptive%20plant%20species%20epithets%20%28I%E2%80%93Z%29 | Since the first printing of Carl Linnaeus's Species Plantarum in 1753, plants have been assigned one epithet or name for their species and one name for their genus, a grouping of related species. These scientific names have been catalogued in a variety of works, including Stearn's Dictionary of Plant Names for Gardeners. William Stearn (1911–2001) was one of the pre-eminent British botanists of the 20th century: a Librarian of the Royal Horticultural Society, a president of the Linnean Society and the original drafter of the International Code of Nomenclature for Cultivated Plants.
The first column below lists seed-bearing species epithets from Stearn's Dictionary, Latin for Gardeners by Lorraine Harrison, The A to Z of Plant Names by Allen Coombes, The Gardener's Botanical by Ross Bayton, and the glossary of Stearn's Botanical Latin. Epithets from proper nouns, proper adjectives, and two or more nouns are excluded, along with epithets used only in species names that are no longer widely accepted. Classical and modern meanings are provided in the third column, along with citations to Charlton T. Lewis's An Elementary Latin Dictionary.
Key
LG = language: (L)atin or (G)reek
L = derived from Latin, or both Classical Latin and Greek (unless otherwise noted)
G = derived from Greek
H = listed by Harrison, and (except as noted) by Bayton
D = listed in Stearn's Dictionary
S = listed in Stearn's Botanical Latin
DS = listed in Stearn's Dictionary, with the word or root word listed in Botanical Latin
C = listed by Coombes
Epithets
See also
Glossary of botanical terms
List of Greek and Latin roots in English
List of Latin and Greek words commonly used in systematic names
List of plant genus names with etymologies: A–C, D–K, L–P, Q–Z
List of plant genera named for people: A–C, D–J, K–P, Q–Z
List of plant family names with etymologies
Notes
Citations
References
Available online at the Perseus Digital Library.
See http://www.plantsoftheworldonline.org |
https://en.wikipedia.org/wiki/Privacy%20concerns%20with%20Facebook | Meta Platforms Inc., or Meta for short, (formerly known as Facebook) has faced a number of privacy concerns. These stem partly from the company's revenue model that involves selling information collected about its users for many things including advertisement targeting. Meta Platforms Inc. has also been a part of many data breaches that have occurred within the company. These issues and others are further described including user data concerns, vulnerabilities in the company's platform, investigations by pressure groups and government agencies, and even issues with students. In addition, employers and other organizations/individuals have been known to use Meta Platforms Inc. for their own purposes. As a result, individuals’ identities and private information have sometimes been compromised without their permission. In response to these growing privacy concerns, some pressure groups and government agencies have increasingly asserted the users’ right to privacy and to be able to control their personal data.
User data concerns
Widening exposure of member information 2011–2012
In 2010, the Electronic Frontier Foundation identified two personal information aggregation techniques called "connections" and "instant personalization". They demonstrated that anyone could get access to information saved to a Facebook profile, even if the information was not intended to be made public. A "connection" is created when a user clicks a "Like" button for a product or service, either on Facebook itself or an external site. Facebook treats such relationships as public information, and the user's identity may be displayed on the Facebook page of the product or service.
Instant Personalization was a pilot program that shared Facebook account information with affiliated sites, such as sharing a user's list of "liked" bands with a music website, so that when the user visits the site, their preferred music plays automatically. The EFF noted that "For users that have not opted out, Insta |
https://en.wikipedia.org/wiki/DataSpii | DataSpii (pronounced data-spy) is a leak that directly compromised the private data of as many as 4 million Chrome and Firefox users via at least eight browser extensions. The eight browser extensions included Hover Zoom, SpeakIt!, SuperZoom, SaveFrom.net Helper, FairShare Unlock, PanelMeasurement, Branded Surveys, and Panel Community Surveys. The private data included personally identifiable information (PII), corporate information (CI), and government information (GI). DataSpii impacted the Pentagon, Zoom, Bank of America, Sony, Kaiser Permanente, Apple, Facebook, Microsoft, Amazon, Symantec, FireEye, Trend Micro, Boeing, SpaceX, and Palo Alto Networks. Highly sensitive information (e.g., private network topology) associated with these corporations and agencies was intercepted and sent to foreign-owned entities.
The data was made publicly available via Nacho Analytics (NA), a marketing intelligence company which described itself as "god mode for the internet." Both paid and free-trial members of NA were provided access to the leaked data. Upon signing up for NA membership, members were then provided access to the data via a Google Analytics account.
DataSpii leaked un-redacted information related to medical records, tax returns, GPS location, travel itinerary, genealogy, usernames, passwords, credit cards, genetic profiles, company memos, employee tasks, API keys, proprietary source code, LAN environment, firewall access codes, proprietary secrets, operational materials, and zero-day vulnerabilities.
DataSpii was discovered and elucidated by cybersecurity researcher Sam Jadali. By requesting data for a single domain via the NA service, Jadali was able to observe what staff members at thousands of companies were working on in near real-time. The NA website stated it collected data from millions of opt-in users. Jadali, along with journalists from Ars Technica and The Washington Post, interviewed impacted users, including individuals and major corporations. Acc |
https://en.wikipedia.org/wiki/Lysozyme%20PEGylation | Lysozyme PEGylation is the covalent attachment of Polyethylene glycol (PEG) to Lysozyme, which is one of the most widely investigated PEGylated proteins.
The PEGylation of proteins has become a common practice of modern therapeutic drugs, as the process is capable of enhancing solubility, thermal stability, enzymatic degradation resistance, and serum half-life of the proteins of interest. Lysozyme, as a natural bactericidal enzyme, lyses the cell wall of various gram-positive bacteria and offers protection against microbial infections. Lysozyme has six lysine residues which are accessible for PEGylation reactions. Thus, the PEGylation of lysozyme, or lysozyme PEGylation, can be a good model system for the PEGylation of other proteins with enzymatic activities by showing the enhancement of its physical and thermal stability while retaining its activity.
Previous works on lysozyme PEGylation showed various chromatographic schemes in order to purify PEGylated lysozyme, which included ion exchange chromatography, hydrophobic interaction chromatography, and size-exclusion chromatography (fast protein liquid chromatography), and proved its stable conformation via circular dichroism and improved thermal stability by enzymatic activity assays, SDS-PAGE, and size-exclusion chromatography (high-performance liquid chromatography).
Methodology
PEGylation
The chemical modification of lysozyme by PEGylation involves the addition of methoxy-PEG-aldehyde (mPEG-aldehyde) with varying molecular sizes, ranging from 2 kDa to 40 kDa, to the protein. The protein and mPEG-aldehyde are dissolved using a sodium phosphate buffer with sodium cyanoborohydride, which acts as a reducing agent and conditions the aldehyde group of mPEG-aldehyde to have a strong affinity towards the lysine residue on the N-terminal of lysozyme. The commonly used molar ratio of lysozyme and mPEG-aldehyde is 1:6 or 1:6.67. When sufficient PEGylation is reached, the reaction can be terminated by addition of ly |
https://en.wikipedia.org/wiki/Human%20impact%20on%20river%20systems | Many river systems are shaped by human activity and through anthropogenic forces. The process of human influence on nature, including rivers, is stated with the beginning of the Anthropocene, which has replaced the Holocene. This long-term impact is analyzed and explained by a wide range of sciences and stands in an interdisciplinary context. The natural water cycle and stream flow is globally influenced and linked to global interconnections. Rivers are an essential component of the terrestrial realm and have been a preferable location for human settlements during history. River is the main expression used for river channels themselves, riparian zones, floodplains and terraces, adjoining uplands dissected by lower channels and river deltas.
Human impact
The relationship between humans and rivers, which represent freshwater environments, is complicated. Rivers serve primarily as a freshwater resource and as sinks for domestic and industrial waste water. The consequences from this usage occur from diverse activities and root themselves in complex, interdisciplinary systems and practices.
Environmental changes in rivers usually result from human development, such as population growth, the dependence on fossil resources, urbanization, global commerce and industrial and agricultural emission. Anthropogenic activities also include discrete elements like the use of fire, domestication of plants and animals, soil development, the establishment of settlements and irrigation. River ecosystems have been transformed downstream from the point of pollution. Active human transformations, river engineering, have altered the river systems and ecosystems.
River engineering
River engineering, a branch of civil engineering, deals with the process of planned human intervention to improve and restore rivers for human and environmental needs. With modern technologies, data collection and modelling, navigation can be improved, dredging reduced and new habitats can be created. River e |
https://en.wikipedia.org/wiki/Beam%20origin%20concept | The beam origin concept is used to describe the mechanisms governing the ecological condition of running waters. It is based on the positive influence of sections in very good condition on sections in less good condition. The idea was first introduced in 2008 by the German Council for Land Stewardship to reach the goals defined in the Water Framework Directive of the European Union.
Background
In order to force politics to take more responsibility in acting against ecological, economic and social problems related to water, the European Union implemented the Water Framework Directive. For each river basin district member, the states had to develop, implement and monitor measures to reach its prescribed goals. As a tool to accomplish this goal, so-called river basin management plans were required.
The implementation is an individual matter for the member states and must be reported regularly. In Germany, the German Council for Land Stewardship worked on a project financially supported by the North Rhine-Westphalia State Agency for Nature, Environment and Consumer Protection and Lennart-Bernadotte-Stiftung, in order to investigate how, in the sense of a beam effect, water biocoenoses in restricted areas can be developed and decoupled from a complete structural improvement in the area concerned. The applicability of stepping stones was thereby to be examined for the beam effect of interventions on running waters, as a parallel to wildlife corridors.
Concept
The main driver of the concept is the beam effect, which indicates the influence of sections in very good ecological condition on sections in less good or rather poor condition with respect to their ecological status. There are two categories of beam effects which are biotic and abiotic. The biotic beam effect relies on the migration or drift of typical aquatic organisms; the abiotic beam effect refers to the transport of positive environmental conditions from one directed downstream. In general, the beam effect |
https://en.wikipedia.org/wiki/Linktree | Linktree is a freemium social media reference landing page developed by Alex Zaccaria, Anthony Zaccaria, and Nick Humphreys, headquartered in Melbourne Australia. Founded in 2016, it serves as a landing page for a person or company's entire associated links in social media, which rarely allows linking to multiple sites. The site was inspired by the developers' annoyance with social media that can't allow multiple hyperlinks.
History
Linktree was established in 2016, out of annoyance regarding social media that does not allow multiple hyperlinks in profiles. The site was created in six hours. It is reported to have gained 3,000 users overnight, which caused the server to crash due to overload. In 2018, Instagram banned the site due to "spam", although it was lifted and Instagram issued an apology. In December 2018, the number of users reached 1 million, then 3 million by the end of 2019. By October 2020, Linktree had gained more than 8 million users.
As of March 2021, the number of users reached nearly 16 million, with an increase of 300% over the previous year.
In August 2021 Linktree announced the acquisition of smart link provider Odesli to become a "one-stop-shop" for musicians seeking to monetize their art.
Features and subscriptions
Linktree is a freemium service: it is free, but also offers a 'Pro' subscription launched in April 2017, which gives more benefits, such as more customization options, more detailed analytics, email sign-up integration, removal of the Linktree logo, etc. Users can upload as many links as they wish despite not subscribing. Pro analytics allows users to view their click-through rates. Both offerings allow users to create a personalized and customizable page, that houses all social media links and official websites. Linktree also partnered with Amazon, allowing users to upload their Amazon store profile as an affiliate link. Amid the George Floyd protests, Linktree allowed users to adopt a 'Support Anti-Racism' icon, which pops a |
https://en.wikipedia.org/wiki/Ars%20Magna%20Lucis%20et%20Umbrae | Ars Magna Lucis et Umbrae ("The Great Art of Light and Shadow") is a 1646 work by the Jesuit scholar Athanasius Kircher. It was dedicated to Ferdinand IV, King of the Romans and published in Rome by Lodovico Grignani. A second edition was published in Amsterdam in 1671 by Johann Jansson. Ars Magna was the first description published in Europe of the illumination and projection of images. The book contains the first printed illustration of Saturn and the 1671 edition also contained a description of the magic lantern.
Ars magna lucis et umbrae followed soon after Kircher's work on magnetism, Magnes sive de Arte Magnetica (1641) and the title was a play on words. In his introduction Kircher notes that the word 'magna' alluded to the powers of the magnet, so that the title could also be read “The Magnetic Art of Light and Shadow”. The work was well known for several decades.
Content
Ars Magna is the first of Kircher's works to follow a symbolic structure. It consists of ten books, represented as the ten strings of the instrument with which the psalmist praises the Lord in Psalm 143. The ten books also have a kabbalistic significance, betokening the ten sefirot.
Kircher dealt comprehensively with many different aspects of light, including physical, astronomical, astrological and metaphysical. He discussed phenomena such as fluorescence, phosphorescence and luminescence, optics and perspective. He also described pareidolia. The work deals first with the Sun, Moon, stars, comets, eclipses and planets. It also discusses phenomena related to light, such as optical illusions, colour, refraction, projection and distortion. The work includes one of the first scientific on phosphorescence and the luminosity of fireflies. He devoted much care to descriptions of instruments such as sundials, moondials and mirrors that make use of light. He had written extensively on these subjects in an earlier work, the Primitiae gnomoniciae catroptricae. Kircher also discussed the "magic |
https://en.wikipedia.org/wiki/Institute%20of%20Computer%20Engineers%20of%20the%20Philippines | The Institute of Computer Engineers of the Philippines (ICpEP, formerly Philippine Institute of Computer Engineers) is a non-profit professional organization of computer engineers in the Philippines. It is registered under the Securities and Exchange Commission as a non-stock and non-profit organization. ICpEP is also the official computer engineering organization for academic community and industry practitioners in the Philippines.
History
In 1992, a group of computer engineers formed a professional organization for computer engineers, the Philippine Institute of Computer Engineers, or PhICEs. But after years of being active and conducting conventions, seminars, and symposia to fellow computer engineers and students, PhICEs became inactive.
In 2008, several computer engineers tried to revive the professional organization after it's been inactive for years. Then the organization was reformed as Institute of Computer Engineers of the Philippines.
History of ICpEP.SE
ICpEP.SE or Institute of Computer Engineers of the Philippines Student Edition, is a student chapter of the ICpEP, which aims to link academics to various colleges and universities. The first group of student chapters started in 2008, it was founded by 11 schools, namely, Adamson University, Asia Pacific College, Central Colleges of the Philippines, De La Salle University, Far Eastern University Institute of Technology, Mapua Institute of Technology, Pamantasan ng Lungsod ng Maynila, Polytechnic University of the Philippines-Manila, STI College-Recto, Technological Institute of the Philippines-Manila, and Technological Institute of the Philippines-Quezon City. And now, there are more than sixty-eight schools across the Philippines that have an ICpEP student chapter.
See also
Institute of Electronics Engineers of the Philippines
Computer engineering
References
External links
ICpEP official website
ICpEP Singapore Chapter website
ICpEP Facebook page
Professional associations based in the P |
https://en.wikipedia.org/wiki/Mirror%20symmetry%20conjecture | In mathematics, mirror symmetry is a conjectural relationship between certain Calabi–Yau manifolds and a constructed "mirror manifold". The conjecture allows one to relate the number of rational curves on a Calabi-Yau manifold (encoded as Gromov–Witten invariants) to integrals from a family of varieties (encoded as period integrals on a variation of Hodge structures). In short, this means there is a relation between the number of genus algebraic curves of degree on a Calabi-Yau variety and integrals on a dual variety . These relations were original discovered by Candelas, de la Ossa, Green, and Parkes in a paper studying a generic quintic threefold in as the variety and a construction from the quintic Dwork family giving . Shortly after, Sheldon Katz wrote a summary paper outlining part of their construction and conjectures what the rigorous mathematical interpretation could be.
Constructing the mirror of a quintic threefold
Originally, the construction of mirror manifolds was discovered through an ad-hoc procedure. Essentially, to a generic quintic threefold there should be associated a one-parameter family of Calabi-Yau manifolds which has multiple singularities. After blowing up these singularities, they are resolved and a new Calabi-Yau manifold was constructed. which had a flipped Hodge diamond. In particular, there are isomorphisms
but most importantly, there is an isomorphism
where the string theory (the A-model of ) for states in is interchanged with the string theory (the B-model of ) having states in . The string theory in the A-model only depended upon the Kahler or symplectic structure on while the B-model only depends upon the complex structure on . Here we outline the original construction of mirror manifolds, and consider the string-theoretic background and conjecture with the mirror manifolds in a later section of this article.
Complex moduli
Recall that a generic quintic threefold in is defined by a homogeneous polynomial of degr |
https://en.wikipedia.org/wiki/Edward%27s%20Pillar | Edward's Pillar or Galle Tower is a masonry column, which was used as a trigonometrical altitude station, located on the summit of Rumassala Kanda in Unawatuna.
The high column is located upon the hill, above sea level. Originally painted white it also served as a leading navigational mark for vessels entering the western channel into Galle Harbour. The pillar was erected in 1875 by W. Burton of the Ceylon Survey Department for trigonometrical work. The station was originally recorded as "Top of Galle Tower or Gibson's Hill near Galle Harbour". Gibson's Hill, now known as Rumassala Kanda, was named after William Carmichael Gibson, the first English Master Attendant of Galle Harbour, who resided on the hill.
Some locals, incorrectly, believe that it was erected as a fake lighthouse during World War I or served as a military lookout.
On 6 July 2007, it was formally recognised by the Government as an Archaeological Protected Monument.
References
See also
Unawatuna Peace Pagoda
Unawatuna
Towers in Sri Lanka
Buildings and structures in Galle District
Archaeological protected monuments in Galle District
Surveying |
https://en.wikipedia.org/wiki/Industrial%202%20of%205 | Industrial 2 of 5. (also known as Standard 2 of 5) is a variable length, discrete, two width symbology. Industrial 2 of 5 is a subset of two-out-of-five codes.
Industrial 2 of 5 is one of the first 1D and oldest barcodes and can encode only digits (0-9). It was invented in 1971 by Identicon Corp. and Computer Identics Corp. At this time, it has only historical value because of low encoding density and restricted charset. Previously it was used for cardboard printing, photo developing envelopes, warehouse sorting systems and for management of physical distribution.
Industrial 2 of 5 has low encoding density because an information can be encoded only in black bars and white spaces are just ignored. Industrial 2 of 5 barcode may include an optional check digit. Most of barcode readers support this symbology.
Encoding
Industrial 2 of 5 can encode digits from 0 to 9. The digit can be encoded in 5 black bars on digit and white spaces are ignored. Any black bar can have two width: wide or narrow. Any white space can have any width by not more than narrow black bar.
Industrial 2 of 5 start/stop patterns and data patterns are split by white space. Industrial 2 of 5 could include optional checksum character which is added to the end of the barcode.
Industrial 2 of 5 features:
character set is a number (0-9);
encoding density low: barcode length on 50% longer than Interleaved 2 of 5 symbology and on 172% than Code 128;
variable length of symbol;
can include optional checking character.
Four bars in encoding scheme, except zero, have own weights which encode value of the symbol. Also, last black bar is used as parity bit to avoid single error. Symbol consists of five bars: two wide bars and three narrow bars. Value of the symbol is a sum of nonzero weights of first four bars.
As an example, we can see digit 3 is encoded. Weight 1 and 2 is not zero and parity bits is 0 means the count of bits is divisible on 2. The result: 1*1 + 1*2 + 0*4 + 0*7 = 3.
The same with dig |
https://en.wikipedia.org/wiki/Mathematical%20Models%20%28Fischer%29 | Mathematical Models: From the Collections of Universities and Museums – Photograph Volume and Commentary is a book on the physical models of concepts in mathematics that were constructed in the 19th century and early 20th century and kept as instructional aids at universities. It credits Gerd Fischer as editor, but its photographs of models are also by Fischer. It was originally published by Vieweg+Teubner Verlag for their bicentennial in 1986, both in German (titled Mathematische Modelle. Aus den Sammlungen von Universitäten und Museen. Mit 132 Fotografien. Bildband und Kommentarband) and (separately) in English translation, in each case as a two-volume set with one volume of photographs and a second volume of mathematical commentary. Springer Spektrum reprinted it in a second edition in 2017, as a single dual-language volume.
Topics
The work consists of 132 full-page photographs of mathematical models, divided into seven categories, and seven chapters of mathematical commentary written by experts in the topic area of each category.
These categories are:
Wire and thread models, of hypercubes of various dimensions, and of hyperboloids, cylinders, and related ruled surfaces, described as "elementary analytic geometry" and explained by Fischer himself.
Plaster and wood models of cubic and quartic algebraic surfaces, including Cayley's ruled cubic surface, the Clebsch surface, Fresnel's wave surface, the Kummer surface, and the Roman surface, with commentary by W. Barth and H. Knörrer.
Wire and plaster models illustrating the differential geometry and curvature of curves and surfaces, including surfaces of revolution, Dupin cyclides, helicoids, and minimal surfaces including the Enneper surface, with commentary by M. P. do Carmo, G. Fischer, U. Pinkall, H. and Reckziegel.
Surfaces of constant width including the surface of rotation of the Reuleaux triangle and the Meissner bodies, described by J. Böhm.
Uniform star polyhedra, described by E. Quaisser.
Models of the |
https://en.wikipedia.org/wiki/2020%20Twitter%20account%20hijacking | On July 15, 2020, between 20:00 and 22:00 UTC, 130 high-profile Twitter accounts were reportedly compromised by outside parties to promote a bitcoin scam. Twitter and other media sources confirmed that the perpetrators had gained access to Twitter's administrative tools so that they could alter the accounts themselves and post the tweets directly. They appeared to have used social engineering to gain access to the tools via Twitter employees. Three individuals were arrested by authorities on July 31, 2020, and charged with wire fraud, money laundering, identity theft, and unauthorized computer access related to the scam.
The scam tweets asked individuals to send bitcoin currency to a specific cryptocurrency wallet, promising the Twitter user that money sent would be doubled and returned as a charitable gesture. Within minutes from the initial tweets, more than 320 transactions had already taken place on one of the wallet addresses, and bitcoins to a value of more than had been deposited in one account before the scam messages were removed by Twitter. In addition, full message history data from eight non-verified accounts were also acquired.
Dmitri Alperovitch, the co-founder of cybersecurity company CrowdStrike, described the incident as "the worst hack of a major social media platform yet." Security researchers expressed concerns that the social engineering used to execute the hack could affect the use of social media in important online discussions, including the lead-up into the 2020 United States presidential election. On July 31, 2020, the U.S. Department of Justice announced charges against three individuals in connection with the incident.
Incident
Forensic analysis of the scam showed that the initial scam messages were first posted by accounts with short, one- or two-character distinctive names, such as "@6". This was followed by cryptocurrency Twitter accounts at around 20:00 UTC on July 15, 2020, including those of Coinbase, CoinDesk and Binance. The |
https://en.wikipedia.org/wiki/EM%20algorithm%20and%20GMM%20model | In statistics, EM (expectation maximization) algorithm handles latent variables, while GMM is the Gaussian mixture model.
Background
In the picture below, are shown the red blood cell hemoglobin concentration and the red blood cell volume data of two groups of people, the Anemia group and the Control Group (i.e. the group of people without Anemia). As expected, people with Anemia have lower red blood cell volume and lower red blood cell hemoglobin concentration than those without Anemia.
is a random vector such as , and from medical studies it is known that are normally distributed in each group, i.e. .
is denoted as the group where belongs, with when belongs to Anemia Group and when belongs to Control Group. Also where , and . See Categorical distribution.
The following procedure can be used to estimate .
A maximum likelihood estimation can be applied:
As the for each are known, the log likelihood function can be simplified as below:
Now the likelihood function can be maximized by making partial derivative over , obtaining:
If is known, the estimation of the parameters results to be quite simple with maximum likelihood estimation. But if is unknown it is much more complicated.
Being a latent variable (i.e. not observed), with unlabeled scenario, the Expectation Maximization Algorithm is needed to estimate as well as other parameters. Generally, this problem is set as a GMM since the data in each group is normally distributed.
In machine learning, the latent variable is considered as a latent pattern lying under the data, which the observer is not able to see very directly. is the known data, while are the parameter of the model. With the EM algorithm, some underlying pattern in the data can be found, along with the estimation of the parameters. The wide application of this circumstance in machine learning is what makes EM algorithm so important.
EM algorithm in GMM
The EM algorithm consists of two steps: the E-step |
https://en.wikipedia.org/wiki/Kinetic%20exclusion%20assay | A kinetic exclusion assay (KinExA) is a type of bioassay in which a solution containing receptor, ligand, and receptor-ligand complex is briefly exposed to additional ligand immobilized on a solid phase.
Description
During the assay, a fraction of the free receptor is captured by the solid phase ligand and subsequently labeled with a fluorescent secondary molecule (Figure 1). The short contact time with the solid phase does not allow significant dissociation of the pre-formed complexes in the solution. Solution dissociation is thus “kinetically excluded” from contributing to the captured receptor and the resulting signal provides a measure of the free receptor in the solution.
Measuring the free receptor as a function of total ligand in a series of equilibrated solutions enables calculation of the equilibrium dissociation constant (Kd). Measuring the free receptor with several points before equilibrium enables measurement of the association rate constant (kon). The off rate (koff) can also be directly measured, however it is usually calculated from the measured Kd and measured kon, (koff = Kd * kon).
Kinetic exclusion assays have been used to measure Kd’s in the nanomolar to femtomolar range.
Applications
Because the fluorescent secondary molecule is applied after capture of the free receptor from solution (Figure 2) the binding constants measured using a kinetic exclusion assay are for unmodified molecules in solution and thus more accurately reflects endogenous binding interactions than methods requiring modification (typically labeling or immobilization) before measurement. Kinetic exclusion assays have been performed using unpurified molecules, in serum, and have measured binding to cell membrane proteins on intact whole cell which brings the measured binding interactions closer to their endogenous state.
Molecules suited for measurement by KinExA are antibodies, recombinant proteins, small molecules, aptamers, lipids, nanobodies, and toxins.
Kinetic e |
https://en.wikipedia.org/wiki/Linear%20time%20property | In model checking, a branch of computer science, linear time properties are used to describe requirements of a model of a computer system. Example properties include "the vending machine does not dispense a drink until money has been entered" (a safety property) or "the computer program eventually terminates" (a liveness property). Fairness properties can be used to rule out unrealistic paths of a model. For instance, in a model of two traffic lights, the liveness property "both traffic lights are green infinitely often" may only be true under the unconditional fairness constraint "each traffic light changes colour infinitely often" (to exclude the case where one traffic light is "infinitely faster" than the other).
Formally, a linear time property is an ω-language over the power set of "atomic propositions". That is, the property contains sequences of sets of propositions, each sequence known as a "word". Every property can be rewritten as "P and Q both occur" for some safety property P and liveness property Q. An invariant for a system is something that is true or false for a particular state. Invariant properties describe an invariant that every reachable state of a model must satisfy, while persistence properties are of the form "eventually forever some invariant holds".
Temporal logics such as linear temporal logic describe types of linear time properties using formulae.
This article is about propositional linear-time properties and cannot handle predicates about program states, so it cannot define a property like: the current value of y determines the number of times that x toggles between 0 and 1 before termination. The more general formalism used in Safety and liveness properties can handle this.
Definition
Let AP be a set of atomic propositions. A word over (the power set of AP) is an infinite sequence of sets of propositions, such as (for the atomic propositions ). A linear time (LT) property over AP is a subset of i.e. a set of words. An example of |
https://en.wikipedia.org/wiki/Elemental%20tetrad | The elemental tetrad is a conceptual framework used in game design. Based on mechanics, aesthetics, stories and technology.
Description
Mechanics describe the rules of the game, what players can and cannot do, while trying to achieve the game's goal and what happens when they try.
Story some sort of sequences of events that unfolds in a game and that can be linear and pre-scripted, or non-linear or even random.
Aesthetics define how the game looks, sounds and feels. Aesthetics has the most direct relationship to the player’s experience.
Technology is what makes the game work, as an essential medium in which other parts of tetrad work: where the aesthetics take place, in which the mechanics will occur, and through which the story will be told.
References
Video game gameplay
Game terminology
Video game development |
https://en.wikipedia.org/wiki/Herbert%20Winful | Herbert Graves Winful (born 3 December 1952) is a Ghanaian-American engineering professor, whose honours include in 2020 the Quantum Electronics Award. He is the Joseph E. and Anne P. Rowe Professor of Electrical Engineering, Arthur F. Thurnau Professor of Electrical Engineering and Computer Science, and a Professor of Physics at the University of Michigan.
Early years and education
Winful was born in London, England, to Margaret Ferguson Graves, a teacher, and Herbert Francis, an engineer. Winful grew up in Cape Coast, Ghana, where he attended Catholic Jubilee School and St Augustine's College. In 1975 he earned a BS in electrical engineering from the Massachusetts Institute of Technology (MIT) (where he was mentored by Hermann A. Haus), followed by an M.S. in Electrical Engineering (1977) and a PhD in 1981 from the University of Southern California. His thesis was titled "Optical bistability in periodic structures and in four-wave mixing processes" and his doctoral advisor was John Marburger.
From 1980 to 1986, Winful was a Principal Member of Technical Staff at GTE Laboratories in Waltham, Massachusetts, conducting research in fiber optics and semiconductor laser physics.
Career
In 1987 Winful took up the post of associate professor in the Electrical Engineering and Computer Sciences (EECS) department at the University of Michigan, and was promoted to become a full professor in 1992, then a year later promoted to an endowed professorship as Thurnau Professor.
As noted by Anis Haffar: "His many contributions to photonics and quantum electronics include pioneering work on nonlinear optical periodic structures; the nonlinear dynamics of coherently coupled laser arrays; the physics of quantum tunneling time; polarization instabilities and distributed-feedback fiber Raman lasers."
A close colleague at the University of Michigan was Gérard Mourou, who in 2018 was co-winner of the Nobel Prize in Physics for the invention of a technique known as Chirped Pulse Amplif |
https://en.wikipedia.org/wiki/Photo-crayotype | Photo-crayotypes (also known as Chromatypes and Crayon Collotypes) were an artistic process used for the hand-colouring of photographs by the application of crayons and pigments over a photographic impression.
History
From its inception in 1839 photographers had been using pigments to hand colour photographs. The most common method used was the addition of colour to the finished daguerreotype, ambrotype or print. But by the 1850s there were two well-established processes based on using photographs as the base layer over which pigments were applied. The first involved printing a light photographic positive on salted paper using a toned or bleached negative to lower the contrast. The other, producing what is generally referred to as a “crayon enlargement”, was to use a magic lantern to project the photograph onto the rear of drawing paper or a canvas. Both of these provided a photographic image which could then be used as the base from which to colour in the features using crayons, oils or watercolours.
England
The English photographer John Jabez Mayall took out a patent on chromotypes as early as 1852 and the process was published in the Photographic Journal in 1853.
Australia
An early Australian proponent of this kind of work was the English painter and photographer Frederick Frith who moved to Australia around 1853. By 1855 he was advertising salt paper prints finished in oils, watercolours or crayons which he called ‘Chromatypes’. These he claimed were made using a special apparatus (perhaps an enlarging camera) manufactured expressly for him by Voigtlander and Son, of Vienna. In October 1856 Douglas Kilburn, of Melbourne, created a sensation selling life sized ‘chromotypes’ which appear to have used the same process as Frith.
The following year similar processes were being touted by Sydney photographers. On 29 August 1857, three advertisements, one following the other, promoted photographs overpainted with crayons, oils or watercolours. In the first of |
https://en.wikipedia.org/wiki/Whitewater%20Interactive%20System%20Development%20with%20Object%20Models | Wisdom (Whitewater Interactive System Development with Object Models) is a software development process and method to design software-intensive interactive systems. It is based on object modelling, and focuses human-computer interaction (HCI) in order to model the software architecture of the system i.e. it is architecture-centric. The focus on HCI while being architecture-centric places Wisdom as a pioneer method within human-centered software engineering. Wisdom was conceived by Nuno Nunes and first published in the years 1999-2000 in order to close the gaps of existing software engineering methods regarding the user interface design.
Notably, the Wisdom method identifies for each use case the tasks of the user, the interaction spaces of the user interface, and the system responsibilities that support that user activity, which are complemented with the data entities used in each case, completing a usable software architecture, an MVC model. The Wisdom model clarifies the relation between the human and the computer-based system, allows rationalization over the software artifacts that must be implemented, therefore facilitating effort affection for a software development team.
From Wisdom, other relevant contributions were derived targeting the enhancement of software development based on the Wisdom model, such as: CanonSketch, Hydra Framework Cruz's
Another relevant contribution is related to effort estimation of software development, the iUCP method, which is based in traditional UCP method leveling the estimation based on the predicted user interface design. A comparison study was carried out using both methods, revealing that there is positive effect in the usage of iUCP when compared to UCP when considering the user interface design, a recurrent situation in nowadays software systems development.
References
Object models
Computer architecture
Software architecture
Software frameworks
Software development process
fa:توسعه سیستم تعاملی Whitewater |
https://en.wikipedia.org/wiki/Hong%20Kong%20Academy%20of%20Engineering%20Sciences | The Hong Kong Academy of Engineering Sciences (HKAES) is an engineering science institution based in Hong Kong. It aims on encouraging and maintaining distinction in the field of engineering with useful resolution, and to promote the development of the science, art and practice of engineering for the social well-being.
History
The Academy was established on 13 September 1994, by Sir S.Y. Chung, Prof. Yau-Kai Cheung, Sir Charles K. Kao and other engineering scholars in Hong Kong.
References
External links
HKAES Website
Professional associations based in Hong Kong
National academies of engineering
Learned societies of Hong Kong
1994 establishments in Hong Kong |
https://en.wikipedia.org/wiki/Assault%20Engineering%20Brigades | Assault Engineering Brigades () or Storm Engineer-Sapper Brigades were formations of the Reserve of the Supreme High Command of the Red Army, being notable for their service during the Second World War. These brigades were designed to storm settlements and to break through heavily fortified enemy lines. These units are commonly abbreviated as ShISBr (), and are occasionally referred to as "armoured infantry" or "cuirass infantry" ().
History
Sapper-engineering assault units were formed in 1943. By 30 May of that year, the formation of the first 15 brigades was completed. Most of these units were formed from existing combat battalions, well-proven in battle. In August 1943, assault engineer-sapper brigades arrived at the front. These were each composed of:
Brigade Command (40 people)
Command Company (87 people)
Motorized Engineer-Scout Company (101 people)
5 Assault Engineer-Sapper Battalions (388 people each)
Light Bridging and Crossing Equipment Crew (36 people)
During the formations of assault engineering brigades, all soldiers over 40 years of age were reassigned. The most distinctive piece of individual equipment used by soldiers of the assault engineering brigades was the SN-42 () steel breastplate.
In December 1943, a procedure was developed for the combat utilization of assault formations. Assault brigades were sent into battle to facilitate key breakthroughs in fortified defensive lines by means of combat engineering and sapping. Success in battle hinged on close coordination with infantry, armoured, mechanized, and artillery units. As soldiers of the assault brigades were not equipped with heavy small arms or their own artillery, they were immediately withdrawn after a successful breakthrough in the enemy lines to limit casualties.
In the spring of 1944 the assault engineering brigades were supplied with ROKS-3 flamethrowers. The 1st, 2nd, 4th, 10th, and 2nd Guards assault engineer-sapper brigades were supplemented with engineer-tank regiments in |
https://en.wikipedia.org/wiki/Plane%E2%80%93plane%20intersection | In analytic geometry, the intersection of two planes in three-dimensional space is a line.
Formulation
The line of intersection between two planes and where are normalized is given by
where
Derivation
This is found by noticing that the line must be perpendicular to both plane normals, and so parallel to their cross product (this cross product is zero if and only if the planes are parallel, and are therefore non-intersecting or entirely coincident).
The remainder of the expression is arrived at by finding an arbitrary point on the line. To do so, consider that any point in space may be written as , since is a basis. We wish to find a point which is on both planes (i.e. on their intersection), so insert this equation into each of the equations of the planes to get two simultaneous equations which can be solved for and .
If we further assume that and are orthonormal then the closest point on the line of intersection to the origin is . If that is not the case, then a more complex procedure must be used.
Dihedral angle
Given two intersecting planes described by and , the dihedral angle between them is defined to be the angle between their normal directions:
References
Euclidean geometry
Computational physics
Geometric algorithms
Geometric intersection
Planes (geometry) |
https://en.wikipedia.org/wiki/Bklyner | Bklyner (pronounced "Brooklyner", often stylized in all-caps) is a hyper-local news site from the borough of Brooklyn in New York City.
It has been described as "telling the stories considered too small for the major newspapers to bother with." Exclusives such as a 27,000 gallon oil spill "that the authorities had not made public" led to legal changes.
Major New York City newspapers such the New York Daily News and the New York Post cite their information as a source.
History
The site began in 2017 when several hyper-local sites merged into one. The publication mostly publishes material online, but has also published printed newspapers.
A neighborhood news website named Ditmas Park Corner, after five years on its own, was folded into Bklyner. Prior to merging into Bklyner, Ditmas Park Corner funded paying a reporter to walk around the neighborhood.
On 26 August 2021, editor Liena Zagare announced that Bklyner would cease publication on 10 September 2021 after over 50000 articles, citing financial sustainability issues and a burnout caused in particular by the two years prior.
Funding
Bklyner, although it carries ads, in 2017 "cut its staff from six full-time reporters to two-and-a-half, primarily because ad revenue had fallen" and also sought "paying subscribers, even though the site remains free." As of early 2020, ads and subscribers was still the support model for free access.
References
Online journalism
2017 establishments in New York City
Free daily newspapers
Mass media in New York City |
https://en.wikipedia.org/wiki/Enhanced%20Transmission%20Selection | Enhanced Transmission Selection (ETS) is a network scheduler scheduling algorithm that has been defined by the Data Center Bridging Task Group of the IEEE 802.1 Working Group. It is a hierarchical scheduler that combines static priority scheduling and a bandwidth sharing algorithms (such as Weighted round robin or Deficit round robin).
Description
The Enhanced Transmission Selection algorithm is one scheduling algorithm supported by IEEE 802.1Q. In Enhanced Transmission Selection, they are two types or queues: Strict priority or Credit-based queues, and bandwidth-assigned queues. Each bandwidth-assigned queue has a bandwidth parameter, and the total for all bandwidth-assigned queue must be 100%.
If there is no frame ready for transmission, in the Strict priority and Credit-based queues, a frame from the bandwidth-assigned queue can be transmitted. A bandwidth-sharing algorithm is in charge of selecting the queue such that the bandwidth consumed by each queue approaches its percentage of the bandwidth leftover by the Strict priority and Credit-based queues. If a queue uses less than its percentage, the remainder of its percentage used by other queues.
The standard does not specify which bandwidth-sharing algorithm must be used since there are a number of variants of bandwidth sharing algorithm, but gives some constraints and references Weighted round robin. The Linux implementation of ETS does not consider Credit-based queues and uses Deficit round robin as bandwidth-sharing algorithm. ETS is also implemented in Microsoft Network Drivers
See also
Deficit round robin
Fairness measure
Max-min fairness
Scheduling algorithm
Statistical time division multiplexing
Weighted round robin
Data center bridging
802.1Qaz working group home page
References
Network scheduling algorithms |
https://en.wikipedia.org/wiki/Ezra%20Brown | Ezra Abraham "Bud" Brown (born January 22, 1944, in Reading, Pennsylvania) is an American mathematician active in combinatorics, algebraic number theory, elliptic curves, graph theory, expository mathematics and cryptography. He spent most of his career at Virginia Tech where he is now Alumni Distinguished Professor Emeritus of Mathematics.
Education and career
Brown earned a BA at Rice University in 1965. He then studied mathematics at Louisiana State University (LSU), getting an MS in 1967 and a PhD in 1969 with the dissertation "Representations of Discriminantal Divisors by Binary Quadratic Forms" under Gordon Pall. He joined Virginia Tech in 1969 becoming Assistant Professor (1969–73), Associate Professor (1973–81), Professor (1981–2005), and Alumni Distinguished Professor of Mathematics and Distinguished Professor of Mathematics (2005–2017). He retired from Virginia Tech in 2017.
Brown became interested in elliptic curves while at LSU and this has remained one of his principal areas of research along with quadratic forms and algebraic number theory in general.
His books include The Unity of Combinatorics (MAA, 2020), co-authored with Richard K. Guy.
Personal life
While at LSU he met his future wife Jo. Brown remained at Virginia Tech until his retirement in 2017.
At the age of 16 Brown taught himself to play the piano, and in college he acted in several musicals and joined an a cappella chorus. In 1989, he joined the Blacksburg Master Chorale and the chorus of Opera Roanoke. Starting in 2011 he took his love of music and math to MathFest where he an his fellow mathematicians composed new words to old show tunes and even took part in a Gilbert-and-Sullivan Singalong at MathFest 2016 with his "Biscuits of Number Theory" co-editor Art Benjamin.
Brown and his mathematical grandfather, L. E. Dickson, have the same birthday.
Selected publications
papers
2018 "Five Families Around a Well: A New Look at an Old Problem" (with Matthew Crawford)
2015 "Many |
https://en.wikipedia.org/wiki/Logarithmic%20Sobolev%20inequalities | In mathematics, logarithmic Sobolev inequalities are a class of inequalities involving the norm of a function f, its logarithm, and its gradient . These inequalities were discovered and named by Leonard Gross, who established them in dimension-independent form, in the context of constructive quantum field theory. Similar results were discovered by other mathematicians before and many variations on such inequalities are known.
Gross proved the inequality:
where is the -norm of , with being standard Gaussian measure on Unlike classical Sobolev inequalities, Gross's log-Sobolev inequality does not have any dimension-dependent constant, which makes it applicable in the infinite-dimensional limit.
In particular, a probability measure on is said to satisfy the log-Sobolev inequality with constant if for any smooth function f
where is the entropy functional.
Notes
References
Axiomatic quantum field theory
Sobolev spaces
Logarithms |
https://en.wikipedia.org/wiki/A%20Topological%20Picturebook | A Topological Picturebook is a book on mathematical visualization in low-dimensional topology by George K. Francis. It was originally published by Springer in 1987, and reprinted in paperback in 2007. The Basic Library List Committee of the Mathematical Association of America has recommended its inclusion in undergraduate mathematics libraries.
Topics
Although the book includes some computer-generated images, most of it is centered on hand drawing techniques. After an introductory chapter on topological surfaces, the cusps in the outlines of surfaces formed when viewing them from certain angles, and the self-intersections of immersed surfaces, the next two chapters are centered on drawing techniques: chapter two concerns ink, paper, cross-hatching, and shading techniques for indicating the curvature of surfaces, while chapter three provides some basic techniques of graphical perspective.
The remaining five chapters of the book provide case studies of different visualization problems in mathematics, called by the book "picture stories". The mathematical topics visualized in these chapters include the Penrose triangle and related optical illusions; the Roman surface and Boy's surface, two different immersions of the projective plane, and deformations between them; sphere eversion and the Morin surface; group theory, the mapping class groups of surfaces, and the braid groups; and knot theory, Seifert surfaces, the Hopf fibration of space by linked circles, and the construction of knot complements by gluing polyhedra.
Audience and reception
Reviewer Athanase Papadopoulos calls the book "a drawing manual for mathematicians". However, reviewer Dave Auckly disagrees, writing that, although the book explains the principles of Francis's own visualizations, it is not really a practical guide to constructing visualizations more generally. Auckly also calls the chapter on perspective "a bizarre mix of mathematical formulas and artistic constructions". Nevertheless, he review |
https://en.wikipedia.org/wiki/Strejc%20method | The Strejc system identification method allows the estimate of the transfer function of a non-periodic, black box-type system based on its step response and is widely used in all branches of industrial and mechanical engineering.
It allows specifically to estimate the order n of the studied system, its time constant and its delay.
To use the Strejc method, it is necessary to apply a step signal to the system and record its tu and tg parameters by observing the inflection point of the response curve. These parameters are then compared with the ones in the numeric table to estimate what order approximates better the system's behaviour and then find the time constant t with the second column (using the appropriate order).
Strejc table
See also
System identification
References
V.Strejc, Näherungsverfahren für aperiodische Übergangscharakteristiken, Automatisierungstechnik, DeGruyter, 1959
J. Mikles, M. Fikar, Process Modelling, Identification, and Control, Springer, 2007, pp. 230-233
Classical control theory
Identification
Identification
Identification |
https://en.wikipedia.org/wiki/2.5D%20integrated%20circuit | A 2.5D integrated circuit (2.5D IC) is an advanced packaging technique that combines multiple integrated circuit dies in a single package without stacking them into a three-dimensional integrated circuit (3D-IC) with through-silicon vias (TSVs). The term "2.5D" originated when 3D-ICs with TSVs were quite new and still very difficult. Chip designers realized that many of the advantages of 3D integration could be approximated by placing bare dies side by side on an interposer instead of stacking them vertically. If the pitch is very fine and the interconnect very short, the assembly can be packaged as a single component with better size, weight, and power characteristics than a comparable 2D circuit board assembly. This half-way 3D integration was facetiously named "2.5D" and the name stuck.
Since then, 2.5D has proven to be far more than just "half-way to 3D."
Some benefits:
An interposer can support heterogeneous integration – that is, dies of different pitch, size, material, and process node.
Placing dies side by side instead of stacking them reduces heat buildup.
Upgrading or modifying a 2.5D assembly is as easy as swapping in a new component and revamping the interposer to suit; much faster and simpler than reworking an entire 3D-IC or System-on-Chip (SoC).
Some sophisticated 2.5D assemblies even incorporate TSVs and 3D components. Several foundries now support 2.5D packaging.
The success of 2.5D assembly has given rise to "chiplets" – small, functional circuit blocks designed to be combined in mix-and-match fashion on interposers. Several high-end products already take advantage of these LEGO-style chiplets; some experts predict the emergence of an industry-wide chiplet ecosystem.
References
Integrated circuits |
https://en.wikipedia.org/wiki/PM%20Sayeed%20Marine%20Birds%20Conservation%20Reserve | PM Sayeed Marine Birds Conservation Reserve is the first protected area for marine birds in India. It is located in the Indian Union Territory of Lakshadweep. It was formed in 2020. It covers an area of 62 km2.
The PM Sayeed Marine Birds Conservation Reserve will be home to four species of pelagic seabirds – the Greater crested tern, Lesser crested tern, Sooty tern, and the Brown noddy.
See also
Dr KK Mohammed Koya Sea Cucumber Conservation Reserve
Pichavaram
Karimpuzha Wildlife Sanctuary
References
Protected areas of India
Tourism in Lakshadweep
Nature conservation in India
Biodiversity
2020 establishments in Lakshadweep |
https://en.wikipedia.org/wiki/Sunspot%20drawing | Sunspot drawing or sunspot sketching is the act of drawing sunspots. Sunspots are darker spots on the Sun's photosphere. Their prediction is very important for radio communication because they are strongly associated with solar activity, which can seriously damage radio equipment.
History
Sunspots were probably first drawn by an English monk John of Worcester on 8 December 1128. There are records of observing sunspots from 28 BC, but that is the first known drawing of sunspots, almost 500 years before the telescope. His drawing seems to come around solar maximum. Five days later, the Korean astronomer saw the northern lights above his country, so this is also the first prediction of coronal mass ejection.
In 1612, Galileo Galilei was writing letters on sunspots to Mark Welser. They were published in 1613. In his telescope, he saw some darker spots on Sun's surface. It seems like he was observing the Sun and drawing sunspots without any filter, which is very hard. He said, "The spots seen at sunset are observed to change the place from one evening to the next, descending from the part of the sun then uppermost, and the morning spots ascend from the part then below ...". From there it seems that he observed the Sun at sunset, but not at sunrise because of the high horizon of Apennines. It is also possible, that he was referring to Scheiner's observation, where he first saw that the Sun is rotating. He complained that he couldn't observe the Sun every morning and evening because of low clouds and so he couldn't see their motion with confidence. He Probably never observed them in the middle of the day. In the same year, his student Benedetto Castelli invented a new method for observing and drawing sunspots, the projection method. Probably, he was never looking at the Sun directly through the telescope.
The Mount Wilson observatory started drawing sunspots by hand in 1917. This tradition continues still today. The early drawers did not draw their shapes and positions |
https://en.wikipedia.org/wiki/Conceptual%20question | Conceptual questions or conceptual problems in science, technology, engineering, and mathematics (STEM) education are questions that can be answered based only on the knowledge of relevant concepts, rather than performing extensive calculations. They contrast with most homework and exam problems in science and engineering that typically require plugging in numerical values into previously discussed formulas. Such "plug-and-chug" numerical problems can often be solved correctly by just matching the pattern of the problem to a previously discussed problem and changing the numerical inputs, which requires significant amounts of time to perform the calculations but does not test or deepen the understanding of how the concepts and formulas should work together. Conceptual questions, therefore, provide a good complement to conventional numerical problems because they need minimal or no calculations and instead encourage the students to engage more deeply with the underlying concepts and how they relate to formulas.
Conceptual problems are often formulated as multiple-choice questions, making them easy to use during in-class discussions, particularly when utilizing active learning, peer instruction, and audience response. An example of a conceptual question in undergraduate thermodynamics is provided below:
During adiabatic expansion of an ideal gas, its temperatureincreases
decreases
stays the same
Impossible to tell/need more information
The use of conceptual questions in physics was popularized by Eric Mazur, particularly in the form of multiple-choice tests that he called ConcepTests. In recent years, multiple websites that maintain lists of conceptual questions have been created by instructors for various disciplines. Some books on physics provide many examples of conceptual questions as well.
Multiple conceptual questions can be assembled into a concept inventory to test the working knowledge of students at the beginning of a course or to track the improvement in |
https://en.wikipedia.org/wiki/Sexual%20segregation%20%28biology%29 | In biology, sexual segregation is the differential use of space, habitats, and resources by males and females, or the separation of males and females into different social groups outside the breeding season. Sexual segregation is widespread among animals, especially among vertebrates that live in groups, and has also been observed in plants. It was first formally proposed by Charles Darwin in his book The Descent of Man, and Selection in Relation to Sex.
Definition
Sexual segregation has traditionally been defined as the differential use of space (spatial segregation) or habitat (habitat segregation) by males and females. Recently, it has also been defined as the separation of males and females into different social groups (social segregation) outside the breeding season. Some authors consider social segregation to be a by-product of habitat segregation but it is now known that social segregation can occur independently of habitat segregation. Conradt (2005) argued that spatial segregation should be treated as a auxiliary concept as both habitat segregation and social segregation can lead to spatial segregation.
References
Ecology
Ethology |
https://en.wikipedia.org/wiki/High-frequency%20oscillations | High-frequency oscillations (HFO) are brain waves of the frequency faster than ~80 Hz, generated by neuronal cell population. High-frequency oscillations can be recorded during an electroencephalagram (EEG), local field potential (LFP) or electrocorticogram (ECoG) electrophysiology recordings. They are present in physiological state during sharp waves and ripples - oscillatory patterns involved in memory consolidation processes. HFOs are associated with pathophysiology of the brain like epileptic seizure and are often recorded during seizure onset. It makes a promising biomarker for the identification of the epileptogenic zone. Other studies points to the HFO role in psychiatric disorders and possible implications to psychotic episodes in schizophrenia.
Background and history
Traditional classification of the frequency bands, that are associated to different functions/states of the brain and consist of delta, theta, alpha, beta and gamma bands. Due to the limited capabilities of the early experimental/medical setup to record fast frequencies, for historical reason, all oscillations above 30 Hz were considered as high frequency and were difficult to investigate. Recent advance in manufacturing electrophysiological setups enables to record electric potential with high temporal and space resolution, and to "catch" dynamics of single cell action potential. In neuroscience nomenclature, there is still a reaming gap between ~100 Hz and multi unit activity (>500 Hz), so these oscillations are often called high gamma or HFO.
Neurophysiological features
HFO are generated by different cellular mechanisms and can be detected in many brain areas. In hippocampus, this fast neuronal activity is effect of the population synchronous spiking of pyramidal cells in the CA3 region and dendritic layer of the CA1, which give rise to a characteristic oscillation pattern (see more in sharp waves and ripples). The HFO occurrence during memory task (encoding and recalling images) was als |
https://en.wikipedia.org/wiki/Mars%20jar | A Mars jar or Mars simulation chamber is a container that simulates the atmosphere of the planet Mars. It is used in astrobiology experiments to determine what kind of life on Mars might be viable.
Features
Mars jars have evolved from simple glass containers that resembled kitchen jars in the 1950s to sophisticated temperature-controlled pressure vessels that are now more commonly called "Mars environmental simulation chamber" or "Mars atmosphere simulation chamber". In such devices, a variety of aspects of the Martian environment can be replicated, such as atmospheric composition and pressure, surface materials, temperature cycles and solar radiation.
History
The concept and the name "Mars jar" originate with Hubertus Strughold, a German physiologist and pioneering space medicine researcher. Strughold described Mars jars in his 1953 publication The Green and Red Planet: A Physiological Study of the Possibility of Life on Mars, in which he also coined the term "astrobiology". By 1956, Mars jars were part of U.S. Air Force research projects into crewed Mars missions.
The concept was popularized outside military circles in 1957 by the biologist Joshua Lederberg, who proposed it to NASA leaders, and then by the astrophysicist and science educator Carl Sagan, who featured Mars jars in his TV shows. According to the science historian Jordan Bimm, Strughold's work was not mentioned in later descriptions of Mars jars because civilian scientists wanted to avoid association with the military and with Strughold's involvement in human experimentation in Nazi Germany.
References
Astrobiology
Atmosphere of Mars |
https://en.wikipedia.org/wiki/Tower%20crane%20anti-collision%20system | A tower crane anti-collision system is an operator support system for tower cranes on construction sites. It helps an operator to anticipate the risk of contact between the moving parts of a tower crane and other tower cranes and structures. In the event that a collision becomes imminent, the system can send a command to the crane's control system, ordering it to slow down or stop. An anti-collision system can describe an isolated system installed on an individual tower crane. It can also describe a site wide coordinated system, installed on many tower cranes in close proximity.
History
Developments in tower crane design and the increasing complexity of construction sites in the 1970’s and 1980’s led to an increase in the quantity and proximity of tower cranes on construction sites. This increased the risk of collisions between cranes, particularly when their operating areas overlapped.
The first tower crane anti-collision systems were developed in France in 1985 by SMIE.
A Ministry of Labour directive issued in 1987 made anti-collision systems compulsory on all tower cranes in France.
In 2011, Hong Kong introduced a "Code of Practice for the Safe Use of Tower Cranes" and Singapore introduced a "Workplace Safety and Health construction Regulation". Both required the provision of an anti-collision system where more than one tower crane is in use.
In 2015, Luxembourg required automatic devices to be installed to avoid the risk of collision between tower cranes.
Collision avoidance with structures and other tower cranes
Various sensors are used to measure the position, velocity and angle of each tower crane’s moving parts. These sensors can be part of the anti-collision system or the crane. This information is sent via radio link to a computer and a display in the operator’s cabin. Several features commonly found across tower crane anti-collision systems use this data.
Zoning
Anti-collision systems allow prohibited zones to be defined. These are areas (such as |
https://en.wikipedia.org/wiki/EFootball | eFootball is a series of association football simulation video games developed and published by Konami. It has been completely rebranded from the original Pro Evolution Soccer (known as Winning Eleven in Japan) series. The game's first year, entitled eFootball 2022, was released on 30 September 2021. It was later changed to the game's second year, eFootball 2023, on August 25, 2022 and the game's third year, eFootball 2024 on September 7, 2023. This game is part of the International Esports Federation's World Championship and North and Eastern Europa League (NEEC).
Development
On 21 July 2021, Konami released a six-minute video revealing the new game. The announcement revealed that the Pro Evolution Soccer brand had been dropped.
The game was released on PlayStation 4, PlayStation 5, Microsoft Windows, Xbox One, and Xbox Series X/S on 30 September 2021. It was built using Unreal Engine 4 for the first time in the franchise.
On 8 October 2021, Konami announced that it would release a new update with fixes for the game's issues on 28 October 2021. The update was delayed and the release postponed to November 2021. Konami then launched the update 0.9.1 on 5 November, and announced that the 1.0 update release was delayed until Spring 2022. Version 1.0.0 of eFootball 2022 was finally announced on 6 April 2022, with release date on 14 April 2022.
On 31 May 2022, Konami announced their roadmap for the rest of 2022 up until 2023 for features such as Master League and the number of teams that can be used in offline mode which will all be released as paid content. However, as of October 2023, features such as Master League and Edit Mode have not been released on PC or consoles, and no further announcements have been made by Konami.
Reception
At launch, eFootball 2022 was panned by critics and players, who criticized the "atrocious" graphics, lack of content, laggy engine and finicky controls. With 92% negative reviews, it became the worst-rated game on Steam a day afte |
https://en.wikipedia.org/wiki/Convex%20drawing | In graph drawing, a convex drawing of a planar graph is a drawing that represents the vertices of the graph as points in the Euclidean plane and the edges as straight line segments, in such a way that all of the faces of the drawing (including the outer face) have a convex boundary. The boundary of a face may pass straight through one of the vertices of the graph without turning; a strictly convex drawing asks in addition that the face boundary turns at each vertex. That is, in a strictly convex drawing, each vertex of the graph is also a vertex of each convex polygon describing the shape of each incident face.
Every polyhedral graph has a strictly convex drawing, for instance obtained as the Schlegel diagram of a convex polyhedron representing the graph. For these graphs, a convex (but not necessarily strictly convex) drawing can be found within a grid whose length on each side is linear in the number of vertices of the graph, in linear time. However, strictly convex drawings may require larger grids; for instance, for any polyhedron such as a pyramid in which one face has a linear number of vertices, a strictly convex drawing of its graph requires a grid of cubic area. A linear-time algorithm can find strictly convex drawings of polyhedral graphs in a grid whose length on each side is quadratic.
Other graphs that are not polyhedral can also have convex drawings, or strictly convex drawings. Some graphs, such as the complete bipartite graph , have convex drawings but not strictly convex drawings. A combinatorial characterization for the graphs with convex drawings is known, and they can be recognized in linear time, but the grid dimensions needed for their drawings and an efficient algorithm for constructing small convex grid drawings of these graphs are not known in all cases.
Convex drawings should be distinguished from convex embeddings, in which each vertex is required to lie within the convex hull of its neighboring vertices. Convex embeddings can exist in |
https://en.wikipedia.org/wiki/Clozapine%20N-oxide | Clozapine N-oxide (CNO) is a synthetic drug used mainly in biomedical research as a ligand to activate DREADD receptors. Although CNO was initially believed to be biologically inert. However, it has been shown not to enter the brain after administration and to reverse metabolise in peripheral tissues to form clozapine. Clozapine can bind to a number of different serotonergic, dopaminergic and adrenergic receptors within the brain. Therefore, behavioural data using the CNO-DREADD system in neuroscience experiments have to be interpreted with caution.
Alternatives to CNO with more affinity, more inert character, and faster kinetics include Compound 21 (C21) and deschloroclozapine (DCZ).
References
Neuroscience
Pharmacology |
https://en.wikipedia.org/wiki/Albert%20Wilansky | Albert "Tommy" Wilansky (13 September 1921, St. John's, Newfoundland – 3 July 2017, Bethlehem, Pennsylvania) was a Canadian-American mathematician, known for introducing Smith numbers.
Biography
Wilansky was educated as an undergraduate at Dalhousie University, where he received an M.A. in mathematics in 1944. From 1944 to 1947 he was a graduate student at Brown University. In 1947 he received his Ph.D. with advisor Clarence Raymond Adams and dissertation An application of Banach linear functionals to the theory of summability.
From 1948 until his official retirement in 1992, Wilansky was a faculty member of the mathematics department of Lehigh University.
Wilansky did research in analysis, specializing in summability theory, linear topological spaces, Banach algebras, and functional analysis. He was the author of several books and the author or co-author of more than 80 articles. He lectured at over 50 different universities. In 1969 he received the Mathematical Association of America's Lester R. Ford Award for his 1968 article Spectral Decomposition of Matrices for High School Students. (The 1969 award was also given individually to 5 other mathematicians.)
Wilansky was married to his first wife from 1947 until her death in 1969. They had two daughters. He had three step-daughters from his second marriage.
Selected publications
Articles
Books
References
1921 births
2017 deaths
20th-century American mathematicians
21st-century American mathematicians
Functional analysts
Mathematical analysts
Dalhousie University alumni
Brown University alumni
Lehigh University faculty
Canadian emigrants to the United States |
https://en.wikipedia.org/wiki/Split%20octal | Syllabic octal and split octal are two similar notations for 8-bit and 16-bit octal numbers, respectively, used in some historical contexts.
Syllabic octal
Syllabic octal is an 8-bit octal number representation that was used by English Electric in conjunction with their KDF9 machine in the mid-1960s.
Although the word 'byte' had been coined by the designers of the IBM 7030 Stretch for a group of eight bits, it was not yet well known, and English Electric used the word 'syllable' for what is now called a byte.
Machine code programming used an unusual form of octal, known locally as 'bastardized octal'. It represented 8 bits with three octal digits but the first digit represented only the two most-significant bits (with values 0..3), whilst the others the remaining two groups of three bits (with values 0..7) each. A more polite colloquial name was 'silly octal', derived from the official name which was syllabic octal (also known as 'slob-octal' or 'slob' notation,).
This 8-bit notation was similar to the later 16-bit split octal notation.
Split octal
Split octal is an unusual address notation used by Heathkit's PAM8 and portions of HDOS for the Heathkit H8 in the late 1970s (and sometimes up to the present). It was also used by Digital Equipment Corporation (DEC).
Following this convention, 16-bit addresses were split into two 8-bit numbers printed separately in octal, that is base 8 on 8-bit boundaries: the first memory location was "000.000" and the memory location after "000.377" was "001.000" (rather than "000.400").
In order to distinguish numbers in split-octal notation from ordinary 16-bit octal numbers, the two digit groups were often separated by a slash (/), dot (.), colon (:), comma (,), hyphen (-), or hash mark (#).
Most mini- and micro-computers used either straight octal (where 377 is followed by 400) or hexadecimal. With the introduction of the optional HA8-6 Z80 processor replacement for the 8080 board, the front-panel keyboard got a new set of |
https://en.wikipedia.org/wiki/Society%20of%20Nepali%20Architects | Society of Nepali Architects(SONA) is an independent non-profit association of architectures in Nepal. It was established in 1990. It has collaboration with the ARCASIA, SAARCH, and UIA.
Objectives
promote the development of architecture and its related art, science and technology throughout Nepal
promote the companionship, kindness and support within the architects and to safeguard their professional rights and interests
increase the participation of the national architects in the national development
enhance the professional ideals among the members
develop relations, fellowship and goodwill with international architect's associations and institutions
Activities
It organizes an Architecture Festival annually in Nepal
It was involved in reconstruction work in association with the American Institute of Architects after the Gorkha earthquake.
It hosted the 14th regional assembly of South Asian architects in 2016.
External links
official website
References
Scientific organisations based in Nepal
Professional associations based in Nepal
1990 establishments in Nepal
Engineering organizations in Nepal |
https://en.wikipedia.org/wiki/Rainbow-independent%20set | In graph theory, a rainbow-independent set (ISR) is an independent set in a graph, in which each vertex has a different color.
Formally, let be a graph, and suppose vertex set is partitioned into subsets , called "colors". A set of vertices is called a rainbow-independent set if it satisfies both the following conditions:
It is an independent set – every two vertices in are not adjacent (there is no edge between them);
It is a rainbow set – contains at most a single vertex from each color .
Other terms used in the literature are independent set of representatives, independent transversal, and independent system of representatives.
As an example application, consider a faculty with departments, where some faculty members dislike each other. The dean wants to construct a committee with members, one member per department, but without any pair of members who dislike each other. This problem can be presented as finding an ISR in a graph in which the nodes are the faculty members, the edges describe the "dislike" relations, and the subsets are the departments.
Variants
It is assumed for convenience that the sets are pairwise-disjoint. In general the sets may intersect, but this case can be easily reduced to the case of disjoint sets: for every vertex , form a copy of for each such that contains . In the resulting graph, connect all copies of to each other. In the new graph, the are disjoint, and each ISR corresponds to an ISR in the original graph.
ISR generalizes the concept of a system of distinct representatives (SDR, also known as transversal). Every transversal is an ISR where in the underlying graph, all and only copies of the same vertex from different sets are connected.
Existence of rainbow-independent sets
There are various sufficient conditions for the existence of an ISR.
Condition based on vertex degree
Intuitively, when the departments are larger, and there is less conflict between faculty members, an ISR should be more likely t |
https://en.wikipedia.org/wiki/Nepal%20Engineers%20Association | Nepal Engineers' Association (NEA) (Nepali:नेपाल ईन्जिनियर्स एसोसियसन) is an independent non-profit organization of engineers of Nepal. Its headquarters is located in Pulchowk, Lalitpur. It was established in 1962. It has the provincial committee in each province of Nepal.
Objectives
It has the following objectives:
promote the development of the engineering science and technology
promote fellowship and safeguard their rights and interests of engineers
enhance participation of the national engineering manpower for national development activities
develop relations, fellowship and goodwill with international engineering associations and institutions.
Activities
NEA celebrates its annual Engineers' day on Shrawan 3.
Veteran engineers are facilitated with lifetime achievement award and young and upcoming fellow engineers are recognized within the event. Apart for annual event NEA also holds international conventions every two years.
Training and rapid response in disaster management
Members
Year 2022: 36,500 plus numbers
International centers
NEA Qatar, established 2004
Australia
Thailand
United Kingdom
Japan
External links
Official website
See also
Nepal Engineering Council
References
Scientific organisations based in Nepal
Professional associations based in Nepal
1962 establishments in Nepal
Engineering organizations in Nepal |
https://en.wikipedia.org/wiki/Graph%20homology | In algebraic topology and graph theory, graph homology describes the homology groups of a graph, where the graph is considered as a topological space. It formalizes the idea of the number of "holes" in the graph. It is a special case of a simplicial homology, as a graph is a special case of a simplicial complex. Since a finite graph is a 1-complex (i.e., its 'faces' are the vertices - which are 0-dimensional, and the edges - which are 1-dimensional), the only non-trivial homology groups are the 0-th group and the 1-th group.
The 1st homology group
The general formula for the 1st homology group of a topological space X is: The example below explains these symbols and concepts in full detail on a graph.
Example
Let X be a directed graph with 3 vertices {x,y,z} and 4 edges {a: x→y, b: y→z, c: z→x, d: z→x}. It has several cycles:
One cycle is represented by the loop a+b+c. Here, the plus sign represents the fact that all edges are travelled at the same direction. Since the addition operation is commutative, the + sign represents the fact that the loops a+b+c, b+c+a, and c+a+b, all represent the same cycle.
A second cycle is represented by the loop a+b+d.
A third cycle is represented by the loop c−d. Here, the minus sign represents the fact that the edge d is travelled backwards.
If we cut the plane along the loop a+b+d, and then cut at c and "glue" at d, we get a cut along the loop a+b+c. This can be represented by the following relation: (a+b+d) + (c-d) = (a+b+c). To formally define this relation, we define the following commutative groups:
C0 is the free abelian group generated by the set of vertices {x,y,z}. Each element of C0 is called a 0-dimensional chain.
C1 is the free abelian group generated by the set of directed edges {a,b,c,d}. Each element of C1 is called a 1-dimensional chain. The three cycles mentioned above are 1-dimensional chains, and indeed the relation (a+b+d) + (c-d) = (a+b+c) holds in the group C1.
Most elements of C1 are not cycles, |
https://en.wikipedia.org/wiki/Evening%20%28painting%29 | Evening (German - Der Abend) is an 1821 oil on canvas painting by Caspar David Friedrich, now in the Niedersächsischen Landesmuseum Hannover. With Morning, Midday and Afternoon, it forms a series on different times of day.
The whole canvas is filled by a pine forest, with a slightly wavy forest floor in brown-green tones with red blooming flowers and vanishing points to far left and far right. In the foreground is a clearing with pine bushes, a path leading diagonally from the left to centre and two figures in old German costume looking at the red and yellow sunset. Also in the background are light and dark clouds and a low horizon in the background.
See also
List of works by Caspar David Friedrich
Bibliography (in German)
Helmut Börsch-Supan, Karl Wilhelm Jähnig: Caspar David Friedrich. Gemälde, Druckgraphik und bildmäßige Zeichnungen, Prestel Verlag, München 1973, (Werkverzeichnis)
Hilmar Frank: Aussichten ins Unermessliche. Perspektivität und Sinnoffenheit bei Caspar David Friedrich. Akademie Verlag, Berlin 2004
Willi Geismeier: Zur Bedeutung und entwicklungsgeschichtlichen Stellung von Naturgefühl und Landschaftsdarstellung bei Caspar David Friedrich. Dissertation, Berlin 1966
Christina Grummt: Caspar David Friedrich. Die Zeichnungen. Das gesamte Werk. 2 Bde., München 2011
Sigrid Hinz (ed.): Caspar David Friedrich in Briefen und Bekenntnissen. Henschelverlag Kunst und Gesellschaft, Berlin 1974
Christian Cay Lorenz Hirschfeld: Theorie der Gartenkunst. Fünf Bände, M. G. Weidmanns Erben und Reich, Leipzig 1797 bis 1785
Werner Hofmann: Caspar David Friedrich. Naturwirklichkeit und Kunstwahrheit. C.H. Beck Verlag, München 2000,
Jens Christian Jensen: Caspar David Friedrich. Leben und Werk. DuMont Verlag, Köln 1999
Wieland Schmied: Caspar David Friedrich. Zyklus, Zeit und Ewigkeit. Prestel Verlag, München 1999
Detlef Stapf: Caspar David Friedrichs verborgene Landschaften. Die Neubrandenburger Kontexte. Greifswald 2014, netzbasiert P-Book
Herrmann Zscho |
https://en.wikipedia.org/wiki/VC-6 | SMPTE ST 2117-1, informally known as VC-6, is a video coding format.
Overview
The VC-6 codec is optimized for intermediate, mezzanine or contribution coding applications. Typically, these applications involve compressing finished compositions for editing, contribution, primary distribution, archiving and other applications where it is necessary to preserve image quality as close to the original as possible, whilst reducing bitrates, and optimizing processing, power and storage requirements. VC-6, like other codecs in this category uses only intra-frame compressions, where each frame is stored independently and can be decoded with no dependencies on any other frame. The codec implements lossless and lossy compression, depending on the encoding parameters that have been selected. It was standardized in 2020. Earlier variants of the codec have been deployed by V-Nova since 2015 under the trade name Perseus. The codec is based on hierarchical data structures called s-trees, and does not involve DCT or wavelet transform compression. The compression mechanism is independent of the data being compressed, and can be applied to pixels as well as other non-image data.
Unlike DCT based codecs, VC-6 is based on hierarchical, repeatable s-tree structures that are similar to modified quadtrees. These simple structures provide intrinsic capabilities, such as massive parallelism and the ability to choose the type of filtering used to reconstruct higher-resolution images from lower-resolution images. In the VC-6 standard an up-sampler developed with an in-loop Convolutional Neural Network is provided to optimize the detail in the reconstructed image, without requiring a large computational overhead. The ability to navigate spatially within the VC-6 bitstream at multiple levels also provides the ability for decoding devices to apply more resources to different regions of the image allowing for Region-of-Interest applications to operate on compressed bitstreams without requiring a |
https://en.wikipedia.org/wiki/Nonadaptive%20radiation | Nonadaptive radiations are a subset of evolutionary radiations (or species flocks) that are characterized by diversification that is not driven by resource partitioning. The species that are a part of a nonadaptive radiation will tend to have very similar niches, and in many (though not all) cases will be morphologically similar. Nonadaptive radiations are driven by nonecological speciation. In many cases, this nonecological speciation is allopatric, and the organisms are dispersal-limited such that populations can be geographically isolated within a landscape with relatively similar ecological conditions. For example, Albinaria land snails on islands in the Mediterranean and Batrachoseps salamanders from California each include relatively dispersal-limited, and closely related, ecologically similar species often have minimal range overlap, a pattern consistent with allopatric, nonecological speciation. In other cases, such as certain damselflies and crickets from Hawaii, there can be range overlap in closely related species, and it is likely that sexual selection (and species recognition) plays a role in maintaining (and perhaps giving rise to) species boundaries.
See also
Adaptive radiation
Species complex
Ecological speciation
References
Speciation
Ecology
Evolutionary biology
Paleobiology |
https://en.wikipedia.org/wiki/Nonecological%20speciation | When speciation is not driven by (or strongly correlated with) divergent natural selection, it can be said to be nonecological, so as to distinguish it from the typical definition of ecological speciation: "It is useful to consider ecological speciation as its own form of species formation because it focuses on an explicit mechanism of speciation: namely divergent natural selection. There are numerous ways other than via divergent natural selection in which populations might become genetically differentiated and reproductively isolated." It is likely that many instances of nonecological speciation are allopatric, especially when the organisms in question are poor dispersers (e.g., land snails, salamanders), however sympatric nonecological speciation may also be possible, especially when accompanied by an "instant" (at least in evolutionary time) loss of reproductive compatibility, as when polyploidization happens. Other potential mechanisms for nonecological speciation include mutation-order speciation and changes in chirality in gastropods.
Nonecological speciation might not be accompanied by strong morphological differentiation, so might give rise to cryptic species, however there are some species that are difficult for humans to differentiate that are strongly differentiated with respect to their resource use, and so are likely a result of ecological speciation (e.g., host shifts in parasites or phytophagous insects). When species recognition/sexual selection plays a strong role in maintaining species boundaries, the species generated by nonecological speciation might be straightforward for humans to differentiate, as in some odonates.
See also
Nonadaptive radiation
References
Ecology
Evolutionary biology |
https://en.wikipedia.org/wiki/HD-PLC | HD-PLC (short for High Definition Power Line Communication) is one of the wired communication technologies. It adopts high frequency band (2 MHz~28 MHz) over mediums like powerlines, phone lines, twisted-pair, and coaxial cables. It is the IEEE 1901-based standard.
Specification and features
There are essentially two different types of HD-PLC: HD-PLC Complete and HD-PLC Multi-hop. They are incompatible.
HD-PLC Complete
This is for high speed applications such as TV, AV, and surveillance camera.
The major technical features include:
IEEE 1901 full compliant
QoS by the priority control
CSMA/CA and DVTP(Dynamic Virtual Token Passing) supported
Concurrent multi-AV stream, VoIP, and file transfer and file transfer supported using IP packet classification
Multi-network access at priority CSMA/CA with network synchronization
HD-PLC Multi-hop
This is for long-distance applications such as smart meter, building network, factory, energy management, and IoT devices.
The major technical features include:
ITU-T G.9905 multihop technology
Common features
Uplinking/downlinking through 432 of 26 MHz (between 1.8 MHz and 28 MHz) bandwidth subcarriers with Wavelet OFDM
Maximum 240 Mbit/s PHY rate
Multilevel modulation for each subcarrier which suits the properties of the power line transmission channel and allows for the best transmission speed
Subcarrier masking with the arbitrary number which can comply with the rules in each country
Forward error correction (FEC) which enables effective frame transmission
Channel estimation launch system with change detector for cycle and transmission channel
HD-PLC network bridging compatible to Ethernet address system
Advanced encryption with 128 bit AES
4th-generation HD-PLC (HD-PLC Quatro Core technology)
We now come to communication speed issues like high-definition video images (4K/8K) or in some cases multi hop technology is not enough to reach an isolated and distant PLC terminal. HD-PLC Quatro Core has |
https://en.wikipedia.org/wiki/SlimRoms | SlimRoms (also Slim7, Slim6, SlimLP, SlimKat or SlimBean) is an Android custom ROM. Its main feature is the many setting options of the user interface.
Since September 2, 2015 SlimRoms is an LTD in Great Britain, after having previously been an e. V. in Germany.
Features
The name of the current SlimRoms version is usually composed of Slim and the code name of the Android version used. An exception is the current version called Slim6 (Android version: Marshmallow).
Some of these features are no longer included in SlimRoms since SlimLP. In most cases the reason is the change of the user interface of Android with the introduction of the material design for Android 5.0 and upwards.
Features no longer available since SlimLP
TRDS
With "the real dark Slim" option (TRDS) dark backgrounds in the menu of the versions SlimKat and SlimBean were coloured deep black and not dark grey like e.g. Stock-Android. Furthermore, some Google Apps were partially inverted. The light backgrounds became black and the font turned white. This option could optionally be adjusted automatically depending on the lighting conditions.
SlimPie
With SlimPIE there was a customizable menu based on CyanogenMod's CM Pie, which appeared semicircular when touched at the edge of the screen. This allowed shortcuts to apps or functions without navigating through menus.
Dialer
The dialer of SlimRom allows you to browse telephone books and additionally displays corresponding telephone book entries for incoming calls. However, this function is only available in Canada and the USA.
Shake Events
Shake events allowed the user to start certain apps or lock the device when shaking it. Here it could be set whether a distinction should be made between horizontal and vertical shaking.
Camera
The camera has been enhanced with SmartCapture and TrueView functions. The former is intended to enable particularly short shutter release times, the latter is intended to display the entire area captured by the camera |
https://en.wikipedia.org/wiki/Yangtze%20Memory%20Technologies | Yangtze Memory Technologies Corp (YMTC) is a Chinese semiconductor integrated device manufacturer specializing in flash memory (NAND) chips. Founded in Wuhan, China, in 2016, with government investment and a goal of reducing the country's dependence on foreign chip manufacturers, the company was formerly a subsidiary of partially state-owned enterprise Tsinghua Unigroup.
YMTC produces enterprise solid state drives under its own brand. Its consumer products are marketed under the brand ZhiTai ().
History
Tsinghua Unigroup founded YMTC in July 2016, with a total investment of US$24 billion, including investments from the Hubei provincial government and the Chinese national "Big Fund" China Integrated Circuit Industry Investment Fund.
In 2018, YMTC released its Xtacking architecture designed for Vertical NAND chips at the Flash Memory Summit, receiving the "Best of Show" award for "Most Innovative Flash Memory Start-up Company". Xtacking enables YMTC to manufacture the memory and the logic circuits on separate wafers and connect them using plasma activation and thermal annealing. According to YMTC, this enables a higher speed for the production process and increases NAND performance. YMTC's 3D NAND flash memory chips were the first to be domestically mass-produced in China. Later in 2018, YMTC announced mass production of its 32-layer 3D NAND flash memory chip, and in September 2019, YMTC reported that it had started mass-producing its 64-layer TLC 3D NAND flash memory chip, with both chips using its Xtacking architecture.
In April 2020, YMTC announced that it had developed a 128-layer 1.33 Tb ( GB) flash memory chip. From 2020 to 2021, YMTC suffered from unsatisfactory yield from its initial risk production of the 128-layer memory chip, averaging around 30 to 40 percent. In September 2020, YMTC unveiled its first line of consumer products under the brand name Zhitai.
, YMTC was planning its second fab with a capacity of 100,000 wafers per month which will double |
https://en.wikipedia.org/wiki/Polynomial%20evaluation | In mathematics and computer science, polynomial evaluation refers to computation of the value of a polynomial when its indeterminates are substituted for some values. In other words, evaluating the polynomial at consists of computing See also
For evaluating the univariate polynomial the most naive method would use multiplications to compute , use multiplications to compute and so on for a total of multiplications and additions.
Using better methods, such as Horner's rule, this can be reduced to multiplications and additions. If some preprocessing is allowed, even more savings are possible.
Background
This problem arises frequently in practice. In computational geometry, polynomials are used to compute function approximations using Taylor polynomials. In cryptography and hash tables, polynomials are used to compute k-independent hashing.
In the former case, polynomials are evaluated using floating-point arithmetic, which is not exact. Thus different schemes for the evaluation will, in general, give slightly different answers. In the latter case, the polynomials are usually evaluated in a finite field, in which case the answers are always exact.
General methods
Horner's rule
Horner's method evaluates a polynomial using repeated bracketing:
This method reduces the number of multiplications and additions to just
Horner's method is so common that a computer instruction "multiply–accumulate operation" has been added to many computer processors, which allow doing the addition and multiplication operations in one combined step.
Multivariate
If the polynomial is multivariate, Horner's rule can be applied recursively over some ordering of the variables.
E.g.
can be written as
An efficient version of this approach was described by Carnicer and Gasca.
Estrin's scheme
While it's not possible to do less computation than Horner's rule (without preprocessing), on modern computers the order of evaluation can matter a lot for the computational efficien |
https://en.wikipedia.org/wiki/Birkhoff%20algorithm | Birkhoff's algorithm (also called Birkhoff-von-Neumann algorithm) is an algorithm for decomposing a bistochastic matrix into a convex combination of permutation matrices. It was published by Garrett Birkhoff in 1946. It has many applications. One such application is for the problem of fair random assignment: given a randomized allocation of items, Birkhoff's algorithm can decompose it into a lottery on deterministic allocations.
Terminology
A bistochastic matrix (also called: doubly-stochastic) is a matrix in which all elements are greater than or equal to 0 and the sum of the elements in each row and column equals 1. An example is the following 3-by-3 matrix:
A permutation matrix is a special case of a bistochastic matrix, in which each element is either 0 or 1 (so there is exactly one "1" in each row and each column). An example is the following 3-by-3 matrix:
A Birkhoff decomposition (also called: Birkhoff-von-Neumann decomposition) of a bistochastic matrix is a presentation of it as a sum of permutation matrices with non-negative weights. For example, the above matrix can be presented as the following sum:
Birkhoff's algorithm receives as input a bistochastic matrix and returns as output a Birkhoff decomposition.
Tools
A permutation set of an n-by-n matrix X is a set of n entries of X containing exactly one entry from each row and from each column. A theorem by Dénes Kőnig says that: Every bistochastic matrix has a permutation-set in which all entries are positive.The positivity graph of an n-by-n matrix X is a bipartite graph with 2n vertices, in which the vertices on one side are n rows and the vertices on the other side are the n columns, and there is an edge between a row and a column iff the entry at that row and column is positive. A permutation set with positive entries is equivalent to a perfect matching in the positivity graph. A perfect matching in a bipartite graph can be found in polynomial time, e.g. using any algorithm for maximum cardinalit |
https://en.wikipedia.org/wiki/Magnetic%20Thermodynamic%20Systems | In thermodynamics and thermal physics, the theoretical formulation of magnetic systems entails expressing the behavior of the systems using the Laws of Thermodynamics. Common magnetic systems examined through the lens of Thermodynamics are ferromagnets and paramagnets as well as the ferromagnet to paramagnet phase transition. It is also possible to derive thermodynamic quantities in a generalized form for an arbitrary magnetic system using the formulation of magnetic work.
Simplified thermodynamic models of magnetic systems include the Ising model, the mean field approximation, and the ferromagnet to paramagnet phase transition expressed using the Landau Theory of Phase Transitions.
Arbitrary magnetic systems
In order to incorporate magnetic systems into the first law of thermodynamics, it is necessary to formulate the concept of magnetic work. The magnetic contribution to the quasi-static work done by an arbitrary magnetic system is
where is the magnetic field and is the magnetic flux density. So the first law of thermodynamics in a reversible process can be expressed as
Accordingly the change during a quasi-static process in the Helmholtz free energy, , and the Gibbs free energy, , will be
Paramagnetic systems
In a paramagnetic system, that is, a system in which the magnetization vanishes without the influence of an external magnetic field, assuming some simplifying assumptions (such as the sample system being ellipsoidal), one can derive a few compact thermodynamic relations. Assuming the external magnetic field is uniform and shares a common axis with the paramagnet, the extensive parameter characterizing the magnetic state is , the magnetic dipole moment of the system. The fundamental thermodynamic relation describing the system will then be of the form . In the more general case where the paramagnet does not share an axis with the magnetic field, the extensive parameters characterizing the magnetic state will be . In this case, the fundamental relati |
https://en.wikipedia.org/wiki/Privacy%20seal | A privacy seal is a type of trust seal or trustmark granted by third party providers for display on a company's website. Companies pay an annual fee (usually ranging from a few hundred to several thousand U.S. dollars) to have an image of the third party provider's seal pasted onto their homepage or privacy policy page. Users can oftentimes click on the seal and be redirected to the web assurance seal service's website which verifies the validity of the privacy seal. They are meant to act as a visual assurance for consumers that the website in question meets a certain standard of privacy. The idea of a privacy seal originates with its physical manifestation – companies have long sought seals of approval like Good Housekeeping to be placed on their tangible products in order to draw in customers who value "quality". While all web assurance seal services follow the guidelines set by the Federal Trade Commission, some providers may have additional requirements. Checks are then conducted on a regular or random basis to ensure compliance. Privacy seals can be applied to various types of e-commerce websites. Some seal providers even create a special privacy seal that is geared toward a certain product like mobile apps or accounting. There are many privacy compliance technology companies, most notably TRUSTArc (formerly TRUSTe), CPA Canada WebTrust, PwC Privacy and BBBOnline.
The U.S. does not regulate e-commerce privacy as stringently as Europe or other countries in the world. With this in mind, U.S. companies have more freedom when it comes to disclosure notices and selling data to third parties for advertising purposes. American based privacy seal companies make a pivot toward the broader field of reliability assurance and complaint resolution in the European marketplace. Privacy seals also have a major presence in the accounting industry of Canada and in general e-commerce in Japan and South Korea.
Privacy seals are meant to boost customers' perception of a company's |
https://en.wikipedia.org/wiki/Underwater%20construction | Underwater construction is industrial construction in an underwater environment. It is a part of the marine construction industry. It can involve the use of a variety of building materials, mainly concrete and steel. There is often, but not necessarily, a significant component of commercial diving involved. Some underwater work can be done by divers, but they are limited by depth and site conditions, and it is hazardous work, with expensive risk reduction and mitigation, and a limited range of suitable equipment. Remotely operated underwater vehicles are an alternative for some classes of work, but are also limited and expensive. When reasonably practicable, the bulk of the work is done out of the water, with underwater work restricted to installation, modification and repair, and inspection.
Scope and applications
Underwater construction is common in the civil engineering, coastal engineering, energy, and petroleum extraction industries.
Civil engineering
Construction below the water table is mostly managed by using cofferdams or pressurised caissons to exclude water sufficiently to work above the local water level within the enclosure, though it may also be possible to keep the water level down by pumping it out as fast as it seeps in, thereby artificially lowering the water table at the worksite.
Dams, reservoirs, canals, locks
Bridges and causeways over bodies of water often require foundation structure below water level. Usually this is done using coffer dams and caissons, which themselves may involve underwater work.
Coastal engineering
Coastal engineering is a branch of civil engineering concerned with the specific demands posed by constructing at or near the coast, as well as the development of the coast itself.
Harbours, docks, breakwaters, jetties, piers, wharfs and similar structures are all immediately adjacent to, or project into coastal waters, and are supported in part by seabed.
Stormwater and sewer outfalls require pipelines to be laid u |
https://en.wikipedia.org/wiki/Applications%20of%20sensitivity%20analysis%20to%20environmental%20sciences | Sensitivity analysis studies the relationship between the output of a model and its input variables or assumptions. Historically, the need for a role of sensitivity analysis in modelling, and many applications of sensitivity analysis have originated from environmental science and ecology.
Early works
Hydrology and water quality are two modelling fields where sensitivity analysis was applied quite early. Relevant examples are the work of Bruce Beck,
George M. Hornberger, Keith Beven and Robert C. Spear.
Other applications
More recent applications encompass snow avalanche models, land depletion, marine biogeochemical modelling, irrigation and again hydrological modelling.
Methods
Several methods related sensitivity analysis have been developed in the context of environmental applications, such as Data Based Mechanistic Model due to Peter Young and VARS due to S. Razavi and H. V.Gupta.
Prevalence across disciplines
In a 2019 work on the take-up of sensitivity analysis in different disciplines, among 19 different subject areas, environmental sciences were found to have the highest number of papers, which become even higher if the papers in earth sciences are included.
Journals
Reference journals for applications of sensitivity analysis in environmental science are Environmental Modelling & Software, Water Resources Research, Water Research, Ecological indicators and others.
Checklists
Sensitivity analysis is part of recent checklists or guidelines for environmental modelling.
Forthcoming special issues
A Special Issue on Sensitivity analysis for environmental modelling in preparation.
References
Mathematical modeling |
https://en.wikipedia.org/wiki/Basque%20Cybersecurity%20Centre | The Basque Cybersecurity Centre (BCSC) is the organization appointed by the Basque Government to promote cybersecurity in the Basque Country. It is made up of departments of the Basque Government (Economic Development and Infrastructures, Safety, Public Governance, and Education) and technology centres (Tecnalia, Vicomtech, Ik4-Ikerlan, and Basque Center for Applied Mathematics).
BCSC is currently a member of FIRST, a global association devoted to offering coordinated responses in the event of computer attacks, and it has achieved CERT homologation. It also takes part in collaborations with other analogous centres on an international scale:
Member of the international cybersecurity consortium Global EPIC.
Member of the European Cyber Security Organisation (ECSO).
In partnership with Instituto Nacional de Ciberseguridad (INCIBE) and INCIBE-CERT.
Entity acknowledged by the European Union Agency for Cybersecurity (ENISA).
Scope and services
As CSIRT team, BCSC offers the following services:
Cybersecurity event management, offering advice on the phone and via email, both in Spanish and Basque.
Vulnerability handling, ensuring communication among the people or firms which discover them, and software or device developers.
Malware analysis, developing strategies for detection, protection and elimination.
Releasing warnings about safety vulnerabilities in IT systems, to lower their risk.
Early alert in case a risk becomes an actual threat.
Spreading information by publishing good practice guides in the scope of cybersecurity. Also, publishing situation reports.
Collaborating with other fast response teams, internet service providers, devices manufacturers and other entities, sharing information.
Training for professionals, through workshops and seminars to promote learning in the field of cybersecurity.
Awareness building for young people and companies and associations working in the industrial field, through seminars focusing on the need to implement the |
https://en.wikipedia.org/wiki/Arthur%20J.%20Robson | Arthur J. Robson is a New Zealand economist whose research interests include game theory and the biological evolution of economic behaviour. In the period between 2003 and 2017, Robson held a Canada Research Chair in Economic Theory and Evolution at Simon Fraser University, where he has been a University Professor since 2017.
Education
Robson graduated with a Bachelor of Science (honors) in pure and applied mathematics from the Victoria University of Wellington in 1968. Subsequently, he obtained a Ph.D. degree in economics from the Massachusetts Institute of Technology in 1974, where he also took courses in pure mathematics. His doctoral thesis’ title was “Congestion, Pollution and Urban Structure” and his supervisor was Robert M. Solow.
Research
Robson's recent research has focused on the biological basis of economics and neuroeconomics. In particular, Robson has worked extensively on the study of the evolution of preferences. As a result of his work, Robson is ranked third by contributions on the field of evolutionary economics according to a RePEc ranking. Furthermore, among economic researchers in general, he is ranked fifth in Canada and 270th in the world according to another RePEc ranking. As of August 2020, Robson had published 72 papers altogether, with 14 of those in top economic journals such as the American Economic Review, Econometrica, the Journal of Political Economy and the Journal of Economic Literature.
Academic positions
Robson held a long-term position at the University of Western Ontario from 1975 to 2005. During this period he also held visiting appointments at several universities including the University of Mannheim from 1985 to 1986 and the University of Michigan in 1989. Later, in 2003, Robson started his current tenure as professor at Simon Fraser University. Since then, Robson also held other visiting appointments in universities such as Johns Hopkins University in 2006.
Awards and honors
Robson is a distinguished fellow of the New Ze |
https://en.wikipedia.org/wiki/Adventures%20Among%20the%20Toroids | Adventures Among the Toroids: A study of orientable polyhedra with regular faces is a book on toroidal polyhedra that have regular polygons as their faces. It was written, hand-lettered, and illustrated by mathematician Bonnie Stewart, and self-published under the imprint "Number One Tall Search Book" in 1970. Stewart put out a second edition, again hand-lettered and self-published, in 1980. Although out of print, the Basic Library List Committee of the Mathematical Association of America has recommended its inclusion in undergraduate mathematics libraries.
Topics
The Platonic solids, known to antiquity, have all faces regular polygons, all symmetric to each other (each face can be taken to each other face by a symmetry of the polyhedron). However, if less symmetry is required, a greater number of polyhedra can be formed while having all faces regular. The convex polyhedra with all faces regular were catalogued in 1966 by Norman Johnson (after earlier study e.g. by Martyn Cundy and A. P. Rollett), and have come to be known as the Johnson solids. Adventures Among the Toroids extends the investigation of polyhedra with regular faces to non-convex polyhedra, and in particular to polyhedra of higher genus than the sphere. Many of these polyhedra can be formed by gluing together smaller polyhedral pieces, carving polyhedral tunnels through them, or piling them into elaborate towers. The toroidal polyhedra described in this book, formed from regular polygons with no self-intersections or flat angles, have come to be called Stewart toroids.
The second edition is rewritten in a different page format, letter sized in landscape mode compared to the tall and narrow by page size of the first edition, with two columns per page. It includes new material on knotted polyhedra and on rings of regular octahedra and regular dodecahedra; as the ring of dodecahedra forms the outline of a golden rhombus, it can be extended to make skeletal pentagon-faced versions of the convex polyh |
https://en.wikipedia.org/wiki/Reciprocity%20%28electrical%20networks%29 | Reciprocity in electrical networks is a property of a circuit that relates voltages and currents at two points. The reciprocity theorem states that the current at one point in a circuit due to a voltage at a second point is the same as the current at the second point due to the same voltage at the first. The reciprocity theorem is valid for almost all passive networks. The reciprocity theorem is a feature of a more general principle of reciprocity in electromagnetism.
Description
If a current, , injected into port A produces a voltage, , at port B and injected into port B produces at port A, then the network is said to be reciprocal. Equivalently, reciprocity can be defined by the dual situation; applying voltage, , at port A producing current at port B and at port B producing current at port A. In general, passive networks are reciprocal. Any network that consists entirely of ideal capacitances, inductances (including mutual inductances), and resistances, that is, elements that are linear and bilateral, will be reciprocal. However, passive components that are non-reciprocal do exist. Any component containing ferromagnetic material is likely to be non-reciprocal. Examples of passive components deliberately designed to be non-reciprocal include circulators and isolators.
The transfer function of a reciprocal network has the property that it is symmetrical about the main diagonal if expressed in terms of a z-parameter, y-parameter, or s-parameter matrix. A non-symmetrical matrix implies a non-reciprocal network. A symmetric matrix does not imply a symmetric network.
In some parametisations of networks, the representative matrix is not symmetrical for reciprocal networks. Common examples are h-parameters and ABCD-parameters, but they all have some other condition for reciprocity that can be calculated from the parameters. For h-parameters the condition is and for the ABCD parameters it is . These representations mix voltages and currents in the |
https://en.wikipedia.org/wiki/List%20of%20SysML%20tools | This article compares SysML tools. SysML tools are software applications which support some functions of the Systems Modeling Language.
General
Features
References
Technical communication
Software comparisons
Diagramming software
Computing-related lists |
https://en.wikipedia.org/wiki/Biotechnology%20industry%20in%20Italy | Biotechnology industry in Italy is a highly innovative and fast-growing sector dedicated to research.
At the end of 2019, there are 696 biotech companies active in Italy.
Industry
The turnover exceeds 12 billion euros, the number of employees exceeds 13,000 units. Between 2017 and 2019, over 50 new innovative start-ups active in biotechnology were registered.
Healthcare
Vaccine
The first Ebola vaccine in the world was developed in the IRBM Science Park laboratories, Pomezia, Rome, Italy.
In the laboratories of the IRBM Science Park a team of Italian and American researchers has developed the Chad3Ebola-Zaire anti-ebola vaccine, a monovalent adenovirus capable of neutralizing the «Zaire» strain of the virus, conceived and produced by OKAIROS, a biotech company founded by Prof. Riccardo Cortese, with whom IRBM set up the Advent equal joint venture.
A COVID-19 vaccine was developed in the IRBM Science Park laboratories, Pomezia, Rome, Italy, in cooperation with Jenner Institute Oxford University.
An other COVID-19 vaccine was developed by ReiThera, Castel Romano, Rome, Italy, in cooperation with Lazzaro Spallanzani National Institute for Infectious Diseases.On 10 August 2020, 3,000 candidates (including doctors) are ready for the test phase. Screening tests carried out throughout the course of the study will be used to select suitable people to test the safety of the vaccine in this early phase of testing (Phase I). Volunteers are divided into two age groups: from 18 to 55, and from 65 to 85. Each group will be divided into three subgroups who will be given a different dosage of vaccine.
Agricultural biotechnology
Research
The research intensity of the biotech sector is significantly higher than that found for the Italian industry as a whole.
Organizations
Ministries
Ministero della Salute
Ministero delle Politiche Agricole Alimentari e Forestali (MiPAAF)
Ministero dell'istruzione, dell'università e della ricerca (MIUR)
Agencies
Federchimica Assobiotec
|
https://en.wikipedia.org/wiki/Mixed%20Hodge%20structure | In algebraic geometry, a mixed Hodge structure is an algebraic structure containing information about the cohomology of general algebraic varieties. It is a generalization of a Hodge structure, which is used to study smooth projective varieties.
In mixed Hodge theory, where the decomposition of a cohomology group may have subspaces of different weights, i.e. as a direct sum of Hodge structures
where each of the Hodge structures have weight . One of the early hints that such structures should exist comes from the long exact sequence of a pair of smooth projective varieties . The cohomology groups (for ) should have differing weights coming from both and .
Motivation
Originally, Hodge structures were introduced as a tool for keeping track of abstract Hodge decompositions on the cohomology groups of smooth projective algebraic varieties. These structures gave geometers new tools for studying algebraic curves, such as the Torelli theorem, Abelian varieties, and the cohomology of smooth projective varieties. One of the chief results for computing Hodge structures is an explicit decomposition of the cohomology groups of smooth hypersurfaces using the relation between the Jacobian ideal and the Hodge decomposition of a smooth projective hypersurface through Griffith's residue theorem. Porting this language to smooth non-projective varieties and singular varieties requires the concept of mixed Hodge structures.
Definition
A mixed Hodge structure (MHS) is a triple such that
is a -module of finite type
is an increasing -filtration on ,
is a decreasing -filtration on ,
where the induced filtration of on the graded piecesare pure Hodge structures of weight .
Remark on filtrations
Note that similar to Hodge structures, mixed Hodge structures use a filtration instead of a direct sum decomposition since the cohomology groups with anti-holomorphic terms, where , don't vary holomorphically. But, the filtrations can vary holomorphically, giving a better define |
https://en.wikipedia.org/wiki/Nearby%20Share | Nearby Share is a functionality developed by Google that allows data to be transferred between devices via Bluetooth and Wi-Fi. It is available on their mobile and desktop operating systems, Android and ChromeOS, as well as Microsoft's Windows. Nearby Share uses Bluetooth, Bluetooth Low Energy, WebRTC, UWB, and peer-to-peer Wi-Fi to allow users to share files and links between devices. It was first released on August 4, 2020.
Nearby Share is not to be confused with Microsoft's similarly-named "nearby sharing" feature, which is only available for PCs running Windows 10 or later and uses Microsoft's own proprietary protocol.
History
Before Nearby Share, Google launched Android Beam in 2011. By 2017, ComputerWorld included Android Beam in a list of "once-trumpeted features that quietly faded away", observing that "despite the admirable marketing effort, Beam never quite worked particularly well, and numerous other systems for sharing stuff proved to be simpler and more reliable."
Nearby Share was officially released for devices running Android Marshmallow and later on August 4, 2020. The program worked much like Apple's AirDrop, allowing users to select "Nearby Share" on the share menu and then to wait for a nearby phone to appear.
In June 2021 with the rollout of ChromeOS 91, Nearby Share was released for ChromeOS with the same features and options as the Android version. During CES 2022, Google announced Nearby Share for Windows. On March 31, 2023, the beta version of the Nearby Share App was released for Windows PCs allowing cross-platform file transfers.
Usage
On Android and ChromeOS, Nearby Share is enabled by going to Connected Devices > Connection preferences > Nearby Share (or Google > Devices & sharing > Nearby Share) in the settings app and enabling "Use Nearby Share." On Windows, Nearby Share is downloaded from android.com. Once the setup program is done installing Nearby Share, or from the Nearby Share settings menu Android, the user will be able to |
https://en.wikipedia.org/wiki/Graph%20Theory%2C%201736%E2%80%931936 | Graph Theory, 1736–1936 is a book in the history of mathematics on graph theory. It focuses on the foundational documents of the field, beginning with the 1736 paper of Leonhard Euler on the Seven Bridges of Königsberg and ending with the first textbook on the subject, published in 1936 by Dénes Kőnig. Graph Theory, 1736–1936 was edited by Norman L. Biggs, E. Keith Lloyd, and Robin J. Wilson, and published in 1976 by the Clarendon Press. The Oxford University Press published a paperback second edition in 1986, with a corrected reprint in 1998.
Topics
Graph Theory, 1736–1936 contains copies, extracts, and translations of 37 original sources in graph theory, grouped into ten chapters and punctuated by commentary on their meaning and context. It begins with Euler's 1736 paper "Solutio problematis ad geometriam situs pertinentis" on the seven bridges of Königsberg (both in the original Latin and in English translation) and ending with Dénes Kőnig's book Theorie der endlichen und unendlichen Graphen. The source material touches on recreational mathematics, chemical graph theory, the analysis of electrical circuits, and applications of graph theory in abstract algebra. Also included are background material and portraits on the mathematicians who originally developed this material.
The chapters of the book organize the material into topics within graph theory, rather than being strictly chronological. The first chapter, on paths, includes maze-solving algorithms as well as Euler's work on Euler tours. Next, a chapter on circuits includes material on knight's tours in chess (a topic that long predates Euler), Hamiltonian cycles, and the work of Thomas Kirkman on polyhedral graphs. Next follow chapters on spanning trees and Cayley's formula, chemical graph theory and graph enumeration, and planar graphs, Kuratowski's theorem, and Euler's polyhedral formula. There are three chapters on the four color theorem and graph coloring, a chapter on algebraic graph theory, and a fin |
https://en.wikipedia.org/wiki/HPG80 | hPG80 refers to the extracellular and oncogenic version of progastrin. This name first appeared in a scientific publication in January 2020. Until that date, scientific publications only mention 'progastrin', without necessarily explicitly specifying whether it is intracellular (in the context of digestion) or extracellular (circulating and detectable in plasma) in the tumor pathological setting.
For more clarity, the remainder of this article uses exclusively the name hPG80 to refer to extracellular progastrin.
A link between this protein and cancer has been known for more than 30 years. hPG80 is involved in most of the biological functions that ensure the existence of cancer. The peptide is secreted by tumor cells and found in the plasma of cancer patients from early stages. It then has functions that are independent of digestion and totally different from progastrin and its only role as an intracellular precursor of gastrin.
Terminology
In the name hPG80, the "h" describes the human species: human; "PG" is a common script for the progastrin protein and the number 80 corresponds to the size of the protein: 80 amino acids.
The name hPG80 was thus proposed in the publication resulting from the work of Professor Benoît You under the management of Dominique Joubert and Alexandre Prieur in order to remove ambiguities between the intracellular version of the protein (in the function of digestion) and its extracellular version of the protein (in the case of cancer patients) which is no longer, despite its name, the precursor of gastrin.
Moreover, the existence of a phonetically identical peptide, the Pro-Gastrin Releasing Peptide (proGRP), accentuated a possible confusion around the name progastrin and the need for a specific name.
Chronology of scientific discoveries on hPG80
1990: hPG80 is secreted by pancreatic cancer cells.
1993 - 1994: hPG80 is secreted by ovarian and colon cancer cells.
1996 - 1997: hPG80 is identified as necessary for the proliferation |
https://en.wikipedia.org/wiki/Adaptive%20machine | The adaptive machine is a category of flexible industrial machinery characterized by the ability to intelligently adapt itself to the product to be produced, e.g. to move individual products through the manufacturing, assembly, inspection, packaging and other process stations required for to produce them.
Examples of intelligent adaptive capabilities
Detecting the size and shape of products in a current production batch and automatically adapting the distance of the actuators used to clamp them and to transport them through the processing line
Adapting the route a product takes through a processing line based on the specifications of the product; each product can take its own individual route through a production line and only stop at processing stations where it actually needs processing. Unnecessary stations are by-passed, via an alternate route or just passed through. This is in stark contrast to fixed-indexing systems such as belt and chain conveyors or round dials that still represent the majority of installed manufacturing equipment.
Exemplary non-characteristics
Using a multitude of work-piece holders specific to each single product variant
Operator intervention for mechanical change-over (e.g. exchanging mechanical cams)
Design approach
At first glance, the adaptive capabilities are rooted in software. But a second look reveals that machines handle physical products. For doing so machines need a proper mechanical design as well as a proper electrical design to power the mechanical movements. An adaptive machine is best designed by applying an interdisciplinary mechatronic design approach where mechanics, electrics and software as well as their interfaces and interactions are considered holistically.
Purpose
The primary function of an adaptive machine is to make production more flexible by enable greater product variety (e.g. with respect to product size and shape) and smaller batches. The ultimate goal of an adaptive machine is mass customizati |
https://en.wikipedia.org/wiki/JOLED | is a Japanese display technology company headquartered in Tokyo, Japan, incorporated in 2015 as the result of a consolidation of the OLED business units of Panasonic and Sony. Notable for pioneering an inkjet printing process for coating emissive materials, the company is specializing in development and production of OLED displays and of cost-effective manufacturing systems for them.
History
Sumitomo Chemical, a main supplier to Japanese electronics makers, acquired Cambridge Display Technology in 2007, procuring polymer organic emitter technology.
Panasonic and Sony, the producer of Sony XEL-1, had been developing OLED technology independently and, in July 2012, struck an agreement to jointly conduct the development to make OLED televisions commercially viable. At the CES 2013, the prototypes of inkjet-printed, RGB OLED television as large as 56-inch were demonstrated by Panasonic. However, aside from unveiling prototypes, the pact between the two companies failed to deliver on its mission and was brought to an end in December 2013.
On July 31, 2014, Sony, Panasonic and Japan Display, the display joint venture of Hitachi, Toshiba and Sony, announced plans to establish a company named JOLED by early 2015 that inherits the OLED operations of Panasonic and Sony, which will withhold some assets related to its professional business, to develop small-to-medium size OLED displays namely for tablet devices, not the larger ones for televisions they had been working on, and that there is a negotiation ongoing for investment with INCJ, a public-private fund in Japan. Apart from INCJ which would inject 75 percent of startup capital, Japan Display (15%), Panasonic (5%), and Sony (5%) were set to participate as initial investors as well.
In January 2015, JOLED formally came into operation, and reportedly started to make use of Sony's WRGB technology and Panasonic's inkjet printing method, targeting markets for tablets, laptops and signage.
In 2016, Japan Display made clear |
https://en.wikipedia.org/wiki/Zolotarev%20polynomials | In mathematics, Zolotarev polynomials are polynomials used in approximation theory. They are sometimes used as an alternative to the Chebyshev polynomials where accuracy of approximation near the origin is of less importance. Zolotarev polynomials differ from the Chebyshev polynomials in that two of the coefficients are fixed in advance rather than allowed to take on any value. The Chebyshev polynomials of the first kind are a special case of Zolotarev polynomials. These polynomials were introduced by Russian mathematician Yegor Ivanovich Zolotarev in 1868.
Definition and properties
Zolotarev polynomials of degree in are of the form
where is a prescribed value for and the are otherwise chosen such that the deviation of from zero is minimum in the interval .
A subset of Zolotarev polynomials can be expressed in terms of Chebyshev polynomials of the first kind, . For
then
For values of greater than the maximum of this range, Zolotarev polynomials can be expressed in terms of elliptic functions. For , the Zolotarev polynomial is identical to the equivalent Chebyshev polynomial. For negative values of , the polynomial can be found from the polynomial of the positive value,
The Zolotarev polynomial can be expanded into a sum of Chebyshev polynomials using the relationship
In terms of Jacobi elliptic functions
The original solution to the approximation problem given by Zolotarev was in terms of Jacobi elliptic functions. Zolotarev gave the general solution where the number of zeroes to the left of the peak value () in the interval is not equal to the number of zeroes to the right of this peak (). The degree of the polynomial is . For many applications, is used and then only need be considered. The general Zolotarev polynomials are defined as
where
is the Jacobi eta function
is the incomplete elliptic integral of the first kind
is the quarter-wave complete elliptic integral of the first kind. That is,
is the Jacobi elliptic |
https://en.wikipedia.org/wiki/F-I%20curve | In neuroscience, a frequency-current curve (fI or F-I curve) is the function that relates the net synaptic current (I) flowing into a neuron to its firing rate (F)
Because the f-I curve only specifies the firing rate rather than exact spike times, it is a concept suited to the rate coding rather than temporal coding model of neuronal computation. Common mathematical models for f-I include the sigmoid, exponential, and rectified linear functions.
The experimental study of how neuronal firing rates can relate to applied currents goes back at least as far as Hodgkin.
References
Neuroscience |
https://en.wikipedia.org/wiki/Microparallelism | Microparallelism is the use of software to exploit fine-grained parallelism within standard computer processors, by writing code that allows the full use of existing parallel units within superscalar processors.
References
Parallel computing
Superscalar microprocessors |
https://en.wikipedia.org/wiki/Slowly%20%28app%29 | Slowly (stylized as SLOWLY) is a geosocial networking application that allows users to exchange delayed messages or "letters". The time taken by a message to be delivered depends on the distance between the sender and the recipient.
History
Slowly was released on iOS in 2017 and on Android a year later. It was featured as App Store's "App of the Day" in over 30 regions worldwide. It was also awarded 2019's "Best Breakthrough App" by Google Play. By January 2019, it had reached 1 million users.
The Slowly web application was launched in version 5.0, in mid-September 2019. In 2020, features such as Dark Mode, the ability to exchange audio notes and to pass a letter without it affecting the user's sent/received ratio were introduced in version 6.0 of the app. A paid membership feature called SLOWLY PLUS was also launched that allows members to double their quotas for the number of friends, excluded topics and regions, and photo sharing.
Operation
Users are required to create a nickname and an avatar for themselves to get started. They can either manually browse user profiles or be "auto-matched" using an algorithm. It lets users search for people using various filters such as common interests or people from particular countries. The app establishes several "House Rules" that must be agreed to before a user can use the app. The "letters" take anything from 30 minutes to 60 hours to "slowly" reach their destination, depending on how far apart the sender and the recipient live. Virtual stamps are collected and attached to the "letters" before mailing them.
A large variety of virtual stamps can also be obtained for free on special days (Holidays, International Days, etc.) or bought in the app's "Stamp Store", and paid by "SLOWLY Coins". These coins can be purchased with local currencies, or obtained as free rewards by watching short in-app video ads. Messages may also include photos and audio notes with the recipient's consent.
Slowly users can also use a "Web Vers |
https://en.wikipedia.org/wiki/DRE-i%20with%20enhanced%20privacy | Direct Recording Electronic with Integrity and Enforced Privacy (DRE-ip) is an End-to-End (E2E) verifiable e-voting system without involving any tallying authorities, proposed by Siamak Shahandashti and Feng Hao in 2016. It improves a previous DRE-i system by using a real-time computation strategy and providing enhanced privacy. A touch-screen based prototype of the system was trialed in the Gateshead Civic Centre polling station on 2 May 2019 during the 2019 United Kingdom local elections with positive voter feedback. A proposal that includes DRE-ip as a solution for large-scale elections was ranked 3rd place in the 2016 Economist Cybersecurity Challenge jointly organized by The Economist and Kaspersky Lab.
Protocol
The DRE-ip protocol is applicable to both onsite polling station voting and remote Internet voting implementations. In the specification below, it is described for polling station voting. The protocol consists of three stages: setup, voting and tallying.
Setup
Let and be two large primes, where . is a subgroup of of prime order . Let and be two random generators of , whose discrete logarithm relationship is unknown. This can be realized by choosing a non-identity element in as and computing based on applying a one-way hash function with the inclusion of election specific information such as the date, election title and questions as the input. All modulo operations are performed with respect to the modulus . Alternatively, the protocol can be implemented using an elliptic curve, while the protocol specification remains unchanged.
Voting
For simplicity, the voting process is described for a single-candidate (Yes/No) election held in a polling station using a touch-screen DRE machine. There are standard ways to extend a single candidate election to support multiple candidates, e.g., providing a Yes/No selection for each of the candidates or using different encoded values for different candidates as described by Baudron et al.
After being au |
https://en.wikipedia.org/wiki/Probability%20and%20statistics | Probability and statistics are two closely related fields in mathematics, sometimes combined for academic purposes. They are covered in several articles:
Probability
Statistics
Glossary of probability and statistics
Notation in probability and statistics
Timeline of probability and statistics |
https://en.wikipedia.org/wiki/ELMo | ELMo ("Embeddings from Language Model") is a word embedding method for representing a sequence of words as a corresponding sequence of vectors. Character-level tokens are taken as the inputs to a bi-directional LSTM which produces word-level embeddings. Like BERT (but unlike the word embeddings produced by "Bag of Words" approaches, and earlier vector approaches such as Word2Vec and GloVe), ELMo embeddings are context-sensitive, producing different representations for words that share the same spelling but have different meanings (homonyms) such as "bank" in "river bank" and "bank balance".
It was created by researchers at the Allen Institute for Artificial Intelligence and University of Washington and first released in February, 2018.
References
Machine learning
Natural language processing
Natural language processing software
Computational linguistics |
https://en.wikipedia.org/wiki/Vadym%20Slyusar | Vadym Slyusar (born 15 October 1964, vil. Kolotii, Reshetylivka Raion, Poltava region, Ukraine) – Soviet and Ukrainian scientist, Professor, Doctor of Technical Sciences, Honored Scientist and Technician of Ukraine, founder of tensor-matrix theory of digital antenna arrays (DAAs), N-OFDM and other theories in fields of radar systems, smart antennas for wireless communications and digital beamforming.
Scientific results
N-OFDM theory
In 1992 Vadym Slyusar patented the 1st optimal demodulation method for N-OFDM signals after Fast Fourier transform (FFT).
From this patent was started the history of N-OFDM signals theory. In this regard, W. Kozek and A. F. Molisch wrote in 1998 about N-OFDM signals with the sub-carrier spacing , that "it is not possible to recover the information from the received signal, even in the case of an ideal channel." But in 2001 Vadym Slyusar proposed such Non-orthogonal frequency digital modulation (N-OFDM) as an alternative of OFDM for communications systems.
The next publication of V. Slysuar about this method has priority in July 2002 before the conference paper of I. Darwazeh and M.R.D. Rodrigues (September, 2003) regarding SEFDM.
The description of the method of optimal processing for N-OFDM signals without FFT of ADC samples was transferred to publication by V. Slyusar in October 2003.
The theory N-OFDM of V. Slyusar inspired numerous investigations in this area of other scientists.
Tensor-matrix theory of digital antenna array
In 1996 V. Slyusar proposed the column-wise Khatri–Rao product to estimate four coordinates of signals sources at a digital antenna array. The alternative concept of the matrix product, which uses row-wise splitting of matrices with a given quantity of rows (Face-splitting product), was proposed by V. Slyusar in 1996 as well.
After these results the tensor-matrix theory of digital antenna arrays and new matrix operations was evolved (such as the Block Face-splitting product, Generalized Face-splitting pr |
https://en.wikipedia.org/wiki/When%20Topology%20Meets%20Chemistry | When Topology Meets Chemistry: A Topological Look At Molecular Chirality is a book in chemical graph theory on the graph-theoretic analysis of chirality in molecular structures. It was written by Erica Flapan, based on a series of lectures she gave in 1996 at the Institut Henri Poincaré, and was published in 2000 by the Cambridge University Press and Mathematical Association of America as the first volume in their shared Outlooks book series.
Topics
A chiral molecule is a molecular structure that is different from its mirror image. This property, while seemingly abstract, can have big consequences in biochemistry, where the shape of molecules is essential to their chemical function, and where a chiral molecule can have very different biological activities from its mirror-image molecule. When Topology Meets Chemistry concerns the mathematical analysis of molecular chirality.
The book has seven chapters, beginning with an introductory overview and ending with a chapter on the chirality of DNA molecules.
Other topics covered through the book include the rigid geometric chirality of tree-like molecular structures such as tartaric acid, and the stronger topological chirality of molecules that cannot be deformed into their mirror image without breaking and re-forming some of their molecular bonds. It discusses results of Flapan and Jonathan Simon on molecules with the molecular structure of Möbius ladders, according to which every embedding of a Möbius ladder with an odd number of rungs is chiral while Möbius ladders with an even number of rungs have achiral embeddings. It uses the symmetries of graphs, in a result that the symmetries of certain graphs can always be extended to topological symmetries of three-dimensional space, from which it follows that non-planar graphs with no self-inverse symmetry are always chiral. It discusses graphs for which every embedding is topologically knotted or linked. And it includes material on the use of knot invariants to detect topol |
https://en.wikipedia.org/wiki/Morse%20Micro | Morse Micro is a Sydney-based developer of Wi-Fi HaLow microprocessors; chips that enable high data rates, with long range and low power consumption. Amongst all Wi-Fi HaLow systems on a chip, Morse Micro processors are reported to be the smallest, fastest, longest-range with lowest-power-use.
The main application of the technology is machine-to-machine communications. With the Internet of things expected to extend to 30 billion devices by 2025, this represents a steeply growing number of users of the technology. The founders plan to be part of "expanding Wi-Fi so it can go into everything, every smoke alarm, every camera."
The firm has its global HQ in Sydney, which is also its main base for R&D, with additional centres in India, China and the United States. As of 2022, Morse Micro was producing more semiconductors than any other Australian-based tech company.
Technology
After eight years' development, the company's Wifi HalLow processor was reported to deliver 10 times the range of conventional Wi-Fi technology, and able to function for several years before needing battery change.
Data rates and range
The microprocessor allows for a range of data rates, depending on the modulation and coding scheme (MCS) used. This can be as low as 150 kilobytes per second using MCS10 with BPSK modulation, to a top rate of 4 megabytes per second using MCS9 at 256 quadrature amplitude modulation.
The chip uses low-bandwidth wireless network protocols, operating in the 1 GHz spectrum, while providing a communications range of 1,000 metres. In one field test, researchers found the technology could sustain high speed data transmission between a device placed by the north end of Sydney Harbour Bridge and a device across the harbour at Sydney Opera House. The company claims their chip provides 10 times the range, 100 times the area and 1000 times the volume of data offered by traditional wi-fi.
Connectivity and energy
To enable networked communications between machines, a sing |
https://en.wikipedia.org/wiki/Parameter%20word | In the mathematical study of combinatorics on words, a parameter word is a string over a given alphabet having some number of wildcard characters. The set of strings matching a given parameter word is called a parameter set or combinatorial cube. Parameter words can be composed, to produce smaller subcubes of a given combinatorial cube. They have applications in Ramsey theory and in computer science in the detection of duplicate code.
Definitions and notation
Formally, a word of length , over a given alphabet , is a sequence of characters, some of which may be drawn from and the others of which are distinct wildcard characters . Each wildcard character is required to appear at least once, but may appear multiple times, and the wildcard characters must appear in the order given by their indexes: the first wildcard character in the word must be , the next one that is different from must be , etc. As a special case, a word over the given
alphabet, without any wildcard characters, is said to be a 0-parameter word. For 1-parameter words, the subscripts may be omitted, as there is no ambiguity between different wildcard characters. The set of all words over , of length , is
A word represents a set of strings (0-parameter words), obtained by substituting a symbol of for each wildcard character. This set of strings is called a parameter set of combinatorial cube, and is called its dimension. A one-dimensional combinatorial cube may be called a combinatorial line.
In a combinatorial cube, each copy of a particular wildcard character must have the same replacement. A generalization of parameter words allows different copies of the same wildcard character to be replaced by different characters from the alphabet, in a controlled way. If is an alphabet and is a group with an action on , then a parameter word is a word together with an assignment of a group element to each wildcard character in the word. The first occurrence of each wildcard character must be a |
https://en.wikipedia.org/wiki/Harmony%20%28operating%20system%29 | Harmony is an experimental computer operating system (OS) developed at the National Research Council Canada in Ottawa. It is a second-generation message passing system that was also used as the basis for several research projects, including robotics sensing and graphical workstation development. Harmony was actively developed throughout the 1980s and into the mid-1990s.
History
Harmony was a successor to the Thoth system developed at the University of Waterloo. Work on Harmony began at roughly the same time as that on the Verex kernel developed at the University of British Columbia. David Cheriton was involved in both Thoth and Verex, and would later go on to develop the V System at Stanford University. Harmony's principal developers included W. Morven Gentleman, Stephen A. MacKay, Darlene A. Stewart, and Marceli Wein.
Early ports of the system existed for a variety of Motorola 68000-based computers, including ones using the VMEbus and Multibus backplanes and in particular the Multibus-based Chorus multiprocessor system at Waterloo. Other hosts included the Atari 520 or 1040 ST. A port also existed for the Digital Equipment Corporation VAX.
Harmony achieved formal verification in 1995.
Features
Harmony was designed as a real-time operating system (RTOS) for robot control. It is a multitasking, multiprocessing system. It is not multi-user. Harmony provided a runtime system (environment) only; development took place on a separate system, originally an Apple Macintosh. For each processor in the system, an image is created that combines Harmony with the one multitask program for that processor at link time, an exception being a case where the kernel is programmed into a read-only memory (ROM).
Although the term did not appear in the original papers, Harmony was later referred to as a microkernel. A key in Harmony is its use of the term task, which in Harmony is defined as the "unit of sequential and synchronous execution" and "the unit of resource ownership". It is |
https://en.wikipedia.org/wiki/Algorithmic%20Combinatorics%20on%20Partial%20Words | Algorithmic Combinatorics on Partial Words is a book in the area of combinatorics on words, and more specifically on partial words. It was written by Francine Blanchet-Sadri, and published in 2008 by Chapman & Hall/CRC in their Discrete Mathematics and its Applications book series.
Topics
A partial word is a string whose characters may either belong to a given alphabet or be a wildcard character. Such a word can represent a set of strings over the alphabet without wildcards, by allowing each wildcard character to be replaced by any single character of the alphabet, independently of the replacements of the other wildcard characters. Two partial words are compatible when they agree on their non-wildcard characters, or equivalently when there is a string that they both match; one partial word contains another partial word if they are compatible and the non-wildcard positions of contain those of ; equivalently, the strings matched by are a subset of those matched by .
The book has 12 chapters, which can be grouped into five larger parts. The first part consists of two introductory chapters defining partial words, compatibility and containment, and related concepts. The second part generalizes to partial words some standard results on repetitions in strings, and the third part studies the problem of characterizing and recognizing primitive partial words, the partial words that have no repetition. Part four concerns codes defined from sets of partial words, in the sense that no two distinct concatenations of partial words from the set can be compatible with each other. A final part includes three chapters on advanced topics including the construction of repetitions of given numbers of copies of partial words that are compatible with each other, enumeration of the possible patterns of repetitions of partial words, and sets of partial words with the property that every infinite string contains a substring matching the set. Each chapter includes a set of exercises, and |
https://en.wikipedia.org/wiki/Mackey%E2%80%93Glass%20equations | In mathematics and mathematical biology, the Mackey–Glass equations, named after Michael Mackey and Leon Glass, refer to a family of delay differential equations whose behaviour manages to mimic both healthy and pathological behaviour in certain biological contexts, controlled by the equation's parameters. Originally, they were used to model the variation in the relative quantity of mature cells in the blood. The equations are defined as:
and
where represents the density of cells over time, and are parameters of the equations.
Equation (), in particular, is notable in dynamical systems since it can result in chaotic attractors with various dimensions.
Introduction
There exist an enormous number of physiological systems that involve or rely on the periodic behaviour of certain subcomponents of the system. For example, many homeostatic processes rely on negative feedback to control the concentration of substances in the blood; breathing, for instance, is promoted by the detection, by the brain, of high CO2 concentration in the blood. One way to model such systems mathematically is with the following simple ordinary differential equation:
where is the rate at which a "substance" is produced, and controls how the current level of the substance discourages the continuation of its production. The solutions of this equation can be found via an integrating factor, and have the form:
where is any initial condition for the initial value problem.
However, the above model assumes that variations in the substance concentration is detected immediately, which often not the case in physiological systems. In order to ease this problem, proposed changing the production rate to a function of the concentration at an earlier point in time, in hope that this would better reflect the fact that there is a significant delay before the bone marrow produces and releases mature cells in the blood, after detecting low cell concentration in the blood. By taking the production r |
https://en.wikipedia.org/wiki/Oxford%E2%80%93Liverpool%20Inventory%20of%20Feelings%20and%20Experiences | The Oxford–Liverpool Inventory of Feelings and Experiences (O-LIFE) is a questionnaire for measuring psychosis-proneness, principally schizotypy. It was introduced in 1995 and has since been used in a variety of experimental and clinical studies. The O-LIFE is a tool with 104 items in the Yes/No response format, although a shorter version (sO-LIFE) can be used as well with only 43 items. It has been used, for instance, in several studies assessing schizotypy in relation to Kamin blocking.
References
Neuroscience
Works about schizophrenia |
https://en.wikipedia.org/wiki/2016%20%28number%29 | 2016 is the natural number following 2015 and preceding 2017.
In mathematics
2016 is a triangular number, being 1 + 2 + 3 + ... + 63. Equivalently, .
2016 is a 24-gonal number and a generalized 28-gonal (icosioctagonal) number .
2016 has 36 divisors.
211 − 25 = 2016.
2016 forms a friendly pair with 360, as and . The number 360 itself is a highly composite number, while 2016, while not highly composite, is highly composite among the positive integers not divisible by five.
2016 × 2 + 1 = 4033. Although 4033 is not prime, as 4033 = 37 × 109, it is a strong pseudoprime to base 2 . Aside from 2016, the only other numbers below 10,000 with this property are 1023, 1638, 2340, 4160, and 7920.
There are 2016 five-cubes in a nine-cube.
2016 is an Erdős–Nicolas number because, while not perfect, 2016 is the sum of its first 31 divisors (up to and including 288).
2016 × 20 = 40,320 = (read as "8 factorial").
is prime. Since 2017 is similarly prime, 201617 + 1 is a semiprime.
Integers |
https://en.wikipedia.org/wiki/Citrix%20Virtual%20Desktops | Citrix Virtual Desktops (formerly XenDesktop) is a desktop virtualization product.
History
The virtualization technology that led to XenDesktop was first developed in 2000 through an open-source hypervisor research project led by Ian Pratt at the University of Cambridge called Xen Project for x86. Pratt founded a company called XenSource in 2004, which made a commercial version of the Xen hypervisor. In 2007, Citrix acquired XenSource, releasing XenDesktop version 2.0 in 2008. The company continues to release updated versions, with XenDesktop 7.6 featuring HDX technology enhancements for audio, video and graphics user experience, as well as a reduction in storage costs associated with virtual desktop deployments as a result of improvements to Citrix provisioning services.
In 2018, the software was renamed Citrix Virtual Desktops.
Product overview
The product's aim is to give employees the ability to work from anywhere while cutting information technology management costs because desktops and applications are centralized. XenDesktop also aims to provide security, because data is not stored on the devices of end users, instead being saved in a centralized datacenter or cloud infrastructure. Citrix developed the software for use by medium to large enterprise customers.
Citrix Workspace is able to manage and deliver applications and desktops using a connection broker called Desktop Delivery Controller. It supports multiple hypervisors, including Citrix Hypervisor, VMware vSphere, Microsoft Hyper-V and Nutanix Acropolis to create virtual machines to run the applications and desktops. The software allows for several types of delivery methods and is compatible with multiple architectures, including desktops and servers, datacenters, and private, public or hybrid clouds. Virtualized applications can be delivered to virtual desktops using Virtual Apps.
Release history
Version 7.5 - March 26, 2014
Version 7.6 - September 30, 2014
Version 7.6 Feature Pack 1 - March 31 |
https://en.wikipedia.org/wiki/Japan%20Society%20for%20Industrial%20and%20Applied%20Mathematics | Japan Society for Industrial and Applied Mathematics (JSIAM) is a Japanese non-profit organization for the field of applied mathematics. JSIAM is not a branch but a Japanese counterpart of the Society for Industrial and Applied Mathematics (SIAM) based in the United States.
Activities
As same as SIAM, JSIAM publishes academic journals in Japanese and English, hold academic conferences, and give awards to applied mathematicians with JSIAM membership.
English Journals and Publications from JSIAM
SIAM Online Magazine
JJIAM (Japan Journal of Industrial and Applied Mathematics)
JSIAM Letters
Finance
The finance of JSIAM is based on membership fee and support from their corporate sponsors. Their sponsors include Canon, Nissan, NEC, NTT, Hitachi, Fujitsu and Ricoh.
Contributions to EASIAM
EASIAM (East Asia Section of SIAM) aims to advance the studies of applied mathematics in eastern Asia. As part of the Eastern Asian community, JSIAM is partially supporting EASIAM. Within their support, EASIAM is publishing the East Asian Journal of Applied Mathematics from the Global Science Press, and hold the EASIAM conference every year.
ICIAM 2023
JSIAM has announced that they will be organizing the International Congress on Industrial and Applied Mathematics in 2023 with the Mathematical Society of Japan.
Notes
See also
Japan Society for the Promotion of Science
Society for Industrial and Applied Mathematics
Applied mathematics
Non-profit organizations based in Japan
1990 establishments in Japan |
https://en.wikipedia.org/wiki/British%20Hydromechanics%20Research%20Association | The British Hydromechanics Research Association is a former government research association that supplies consulting engineering over fluid dynamics.
History
It was formed on 20 September 1947 in Essex, under the Companies Act 1929
It had moved to Bedfordshire by the 1960s. In the 1970s it was known as BHRA Fluid Engineering.
Next door was the National Centre for Materials Handling, set up by the Ministry of Technology (MinTech), later known as the National Materials Handling Centre.
On 16 October 1989 it became a private consultancy.
Fluid engineering
The BHRA conducted most of the research for the aerodynamics of British power station infrastructure in the 1960s, such as cooling towers.
In 1966 it designed an early Thames flood barrier.
Computational fluid dynamics
It developed early CFD software.
Visits
On Tuesday 21 June 1966, the new Bedfordshire laboratories were opened by Duke of Edinburgh.
Structure
The organisation, Framatome BHR, is now in Cranfield in west Bedfordshire, near the M1.
See also
Bierrum, has built and designed Britain's power station cooling towers since 1965, also in Bedfordshire.
References
External links
BHR Group
1947 establishments in the United Kingdom
British research associations
Central Bedfordshire District
Computational fluid dynamics
Engineering research institutes
Hydraulic engineering organizations
Hydraulic laboratories
Research institutes established in 1947
Science and technology in Bedfordshire
Science and technology in Essex
Wind tunnels |
https://en.wikipedia.org/wiki/OroraTech | OroraTech is a German aerospace start-up company providing wildfire monitoring by employing nanosatellites. It was founded in 2018 as a university spin-off at the Technical University of Munich (TUM). The headquarters are in Munich, Germany.
History
OroraTech's key idea had been developed during the MOVE-II CubeSat project and WARR at the TUM. Starting as a spin-off in January 2017, the company was incorporated as Orbital Oracle Technologies GmbH (short: OroraTech) in September 2018. Since OroraTech's technology is based on academic research at the TUM, TUM professors Ulrich Walter, a former astronaut, and Alexander W. Koch act as advisors to the company.
Technology
Wildfire detection using infrared sensors in space had been proposed as a technology since the 1990s. Technological advances, notably sunk space launch cost, enabled non-state actors to enter the market. As such, OroraTech operates a software platform for the detection and monitoring of wildfires based on measuring thermal-infrared radiation from space. The company is using data from existing satellites and develops their own constellation of 3-U CubeSats with thermal-infrared cameras to further improve temporal and spatial resolution of fire detection.
The software platform generates various overlays on base maps to visualize fire risk and fire detections. At the current stage, the platform uses data from twelve satellites in polar and geostationary orbits, including such by NASA, ESA, and EUMETSAT. In early 2020, the platform had around 100 active users.
The satellite technology is based on research from the MOVE-II project at the Chair of Astronautics (LRT) at the TUM. During the project, a 1-Unit CubeSat was launched with SpaceX in December 2018. OroraTech's first nanosatellite, based on the original CubeSat, was developed to reach 10 cm x 10 cm x 34 cm in size, weighing around 1.2 kg, and it was launched on 13 January 2022 as part of SpaceX's Transporter-3 rideshare mission. The satellite fe |
https://en.wikipedia.org/wiki/Graham%E2%80%93Rothschild%20theorem | In mathematics, the Graham–Rothschild theorem is a theorem that applies Ramsey theory to combinatorics on words and combinatorial cubes. It is named after Ronald Graham and Bruce Lee Rothschild, who published its proof in 1971. Through the work of Graham, Rothschild, and in 1972, it became part of the foundations of structural Ramsey theory. A special case of the Graham–Rothschild theorem motivates the definition of Graham's number, a number that was popularized by Martin Gardner in Scientific American and listed in the Guinness Book of World Records as the largest number ever appearing in a mathematical proof.
Background
The theorem involves sets of strings, all having the same length , over a finite alphabet, together with a group acting on the alphabet. A combinatorial cube is a subset of strings determined by constraining some positions of the string to contain a fixed letter of the alphabet, and by constraining other pairs of positions to be equal to each other or to be related to each other by the group action. This determination can be specified more formally by means of a labeled parameter word, a string with wildcard characters in the positions that are not constrained to contain a fixed letter and with additional labels describing which wildcard characters must be equal or related by the group action. The dimension of the combinatorial cube is the number of free choices that can be made for these wildcard characters. A combinatorial cube of dimension one is called a combinatorial line.
For instance, in the game of tic-tac-toe, the nine cells of a tic-tac-toe board can be specified by strings of length two over the three-symbol alphabet {1,2,3} (the Cartesian coordinates of the cells), and the winning lines of three cells form combinatorial lines. Horizontal lines are obtained by fixing the -coordinate (the second position of the length-two string) and letting the -coordinate be chosen freely, and vertical lines are obtained by fixing the -coordinate and |
https://en.wikipedia.org/wiki/Journey%20into%20Geometries | Journey into Geometries is a book on non-Euclidean geometry. It was written by Hungarian-Australian mathematician Márta Svéd, and published in 1991 by the Mathematical Association of America in their MAA Spectrum book series.
Topics
Journey into Geometries is written as a conversation between three characters: Alice, from Alice's Adventures in Wonderland (but older and familiar with Euclidean geometry), Lewis Carroll, the author of Alice's adventures, and a modern mathematician named "Dr. Whatif". Its topics include hyperbolic geometry, inversive geometry, and projective geometry, following an arrangement of these topics credited to Australian mathematician Carl Moppert, and possibly based on an earlier German-language textbook on similar topics by F. Gonseth and P. Marti.
As in Alice's original adventures, the first part of the book is arranged as a travelogue. This part of the book has six chapters, each ending with a set of exercises. Following these chapters, more conventionally written material covers geometric axiom systems and provides solutions to the exercises.
Audience and reception
Reviewer William E. Fenton is unsure of the audience of the book, writing that it is not suitable as a textbook and would scare most undergraduates, but is too unserious for graduate students. David A. Thomas identifies the audience as "people who like to play with mathematical ideas".
Fenton criticizes the book's style as a little too glib and lead-footed, and its illustrations as amateurish. H. W. Guggenheimer faults the treatment of projective geometry as "rather sketchy". Nevertheless Fenton writes that he found the book engrossing and well-organized, particularly praising its exercises. Both Fenton and Guggenheimer recommend the book to talented students of mathematics, and both Fenton and David A. Thomas suggest it as auxiliary reading for geometry courses.
References
External links
Journey into Geometries on the Internet Archive
Non-Euclidean geometry
Mathematics |
https://en.wikipedia.org/wiki/Integrable%20module | In algebra, an integrable module (or integrable representation) of a Kac–Moody algebra (a certain infinite-dimensional Lie algebra) is a representation of such that (1) it is a sum of weight spaces and (2) the Chevalley generators of are locally nilpotent. For example, the adjoint representation of a Kac–Moody algebra is integrable.
References
External links
Algebra |
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