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https://en.wikipedia.org/wiki/Darcy%20%28unit%29 | The darcy (or darcy unit) and millidarcy (md or mD) are units of permeability, named after Henry Darcy. They are not SI units, but they are widely used in petroleum engineering and geology. The unit has also been used in biophysics and biomechanics, where the flow of fluids such as blood through capillary beds and cerebrospinal fluid through the brain interstitial space is being examined. A darcy has dimensional units of length2.
Definition
Permeability measures the ability of fluids to flow through rock (or other porous media). The darcy is defined using Darcy's law, which can be written as:
where:
{|
| || is the volumetric fluid flow rate through the medium
|-
| || is the area of the medium
|-
| || is the permeability of the medium
|-
| || is the dynamic viscosity of the fluid
|-
| || is the applied pressure difference
|-
| || is the thickness of the medium
|}
The darcy is referenced to a mixture of unit systems. A medium with a permeability of 1 darcy permits a flow of 1 cm3/s of a fluid with viscosity 1 cP (1 mPa·s) under a pressure gradient of 1 atm/cm acting across an area of 1 cm2.
Typical values of permeability range as high as 100,000 darcys for gravel, to less than 0.01 microdarcy for granite. Sand has a permeability of approximately 1 darcy.
Tissue permeability, whose measurement in vivo is still in its infancy, is somewhere in the range of 0.01 to 100 darcy.
Origin
The darcy is named after Henry Darcy. Rock permeability is usually expressed in millidarcys (md) because rocks hosting hydrocarbon or water accumulations typically exhibit permeability ranging from 5 to 500 md.
The odd combination of units comes from Darcy's original studies of water flow through columns of sand. Water has a viscosity of 1.0019 cP at about room temperature.
The unit abbreviation "d" is not capitalized (contrary to industry use). The American Association of Petroleum Geologists uses the following unit abbreviations and grammar in their publications:
darcy (plural |
https://en.wikipedia.org/wiki/Briggera | Briggera is a genus of diatom known from the fossil record.
Species
B. ornithocephala. |
https://en.wikipedia.org/wiki/Morchella%20brunnea | Morchella brunnea is a species of fungus in the family Morchellaceae. Described as new to science in 2012, it is known from Oregon, where it fruits under hardwood trees. |
https://en.wikipedia.org/wiki/Global%20precedence | Images and other stimuli contain both local features (details, parts) and global features (the whole). Precedence refers to the level of processing (global or local) to which attention is first directed. Global precedence occurs when an individual more readily identifies the global feature when presented with a stimulus containing both global and local features. The global aspect of an object embodies the larger, overall image as a whole, whereas the local aspect consists of the individual features that make up this larger whole. Global processing is the act of processing a visual stimulus holistically. Although global precedence is generally more prevalent than local precedence, local precedence also occurs under certain circumstances and for certain individuals. Global precedence is closely related to the Gestalt principles of grouping in that the global whole is a grouping of proximal and similar objects. Within global precedence, there is also the global interference effect, which occurs when an individual is directed to identify the local characteristic, and the global characteristic subsequently interferes by slowing the reaction time.
Basic methods
Global precedence was first studied using the Navon figure, where many small letters are arranged to form a larger letter that either does or does not match. Variations of the original Navon figure include both shapes and objects.
Individuals presented with a Navon figure will be given one of two tasks. In one type of task, participants are told before the presentation of the stimulus whether to focus on a global or local level, and their accuracy and reaction times are recorded.
In another type of task, participants are first presented with a target stimulus, and later presented with two different visuals. One of the visuals matches the target stimulus on the global level, while the other visual matches the target stimulus on the local level. In this condition, experimenters note which of the t |
https://en.wikipedia.org/wiki/Uniform%20consensus | In computer science, Uniform consensus is a distributed computing problem that is a similar to the consensus problem with one more condition which is no two processes (whether faulty or not) decide differently.
More specifically one should consider this problem:
Each process has an input, should on decide an output (one-shot problem)
Uniform Agreement: every two decisions are the same
Validity: every decision is an input of one of the processes
Termination: eventually all correct processes decide |
https://en.wikipedia.org/wiki/Gigapackets | Gigapackets are billions (109) of packets or datagrams. The packet is the fundamental unit of information in computer networks.
Data transfer rates in gigapackets per second are associated with high speed networks, especially fiber optic networks. The bit rates that are used to create gigapackets are in the range of gigabits per second. These rates are seen in network speeds of gigabit Ethernet or 10 Gigabit Ethernet and SONET Optical Carrier rates of OC-48 at 2.5 Gbit/s and OC-192 at 10 Gbit/s. |
https://en.wikipedia.org/wiki/Indulata%20Sukla | Indulata L. Sukla (7 March 1944 – 30 June 2022) was an Indian academic, who was professor of mathematics for more than three decades at Sambalpur University, Sambalpur, Odisha.
She did her schooling from Maharani Prem Kumari Girls’ School and B.Sc. with Mathematics Honours from M.P.C. College, Baripada. She completed her M.Sc. in Mathematics from Ravenshaw College, Cuttack in 1966, and had a brief stint as a lecturer in M.P.C. College, before moving to the University of Jabalpur with a CSIR Fellowship to pursue Ph.D. under the supervision of Tribikram Pati. While pursuing her researches, she joined Sambalpur University in November 1970 as a lecturer in the School of Mathematical Sciences, and continued there till her retirement in March 2004.
She is the author of the textbook Number Theory and Its Applications to Cryptography (Cuttack: Kalyani Publishers, 2000).
In her research, she worked with English mathematician Brian Kuttner on Fourier Series.
She was a Life Member of the American Mathematical Society (AMS) and the Indian Mathematical Society (IMS).
Awards and honours
The Orissa Mathematical Society (OMS) gave her the Lifetime Achievement Award for her work in Number Theory, Cryptography and Analysis. She received the award from Professor Ramachandran Balasubramanian, Director of the Institute of Mathematical Sciences, Chennai at the 42nd Annual Conference of OMS held at Vyasanagar Autonomous College, Jajpur Road, Orissa on 7 February 2015.
Selected publications
.
. |
https://en.wikipedia.org/wiki/Behavioural%20genetics | Behavioural genetics, also referred to as behaviour genetics, is a field of scientific research that uses genetic methods to investigate the nature and origins of individual differences in behaviour. While the name "behavioural genetics" connotes a focus on genetic influences, the field broadly investigates the extent to which genetic and environmental factors influence individual differences, and the development of research designs that can remove the confounding of genes and environment. Behavioural genetics was founded as a scientific discipline by Francis Galton in the late 19th century, only to be discredited through association with eugenics movements before and during World War II. In the latter half of the 20th century, the field saw renewed prominence with research on inheritance of behaviour and mental illness in humans (typically using twin and family studies), as well as research on genetically informative model organisms through selective breeding and crosses. In the late 20th and early 21st centuries, technological advances in molecular genetics made it possible to measure and modify the genome directly. This led to major advances in model organism research (e.g., knockout mice) and in human studies (e.g., genome-wide association studies), leading to new scientific discoveries.
Findings from behavioural genetic research have broadly impacted modern understanding of the role of genetic and environmental influences on behaviour. These include evidence that nearly all researched behaviours are under a significant degree of genetic influence, and that influence tends to increase as individuals develop into adulthood. Further, most researched human behaviours are influenced by a very large number of genes and the individual effects of these genes are very small. Environmental influences also play a strong role, but they tend to make family members more different from one another, not more similar.
History
Selective breeding and the domestication of anim |
https://en.wikipedia.org/wiki/List%20of%20Bluetooth%20profiles | In order to use Bluetooth, a device must be compatible with the subset of Bluetooth profiles (often called services or functions) necessary to use the desired services. A Bluetooth profile is a specification regarding an aspect of Bluetooth-based wireless communication between devices. It resides on top of the Bluetooth Core Specification and (optionally) additional protocols. While the profile may use certain features of the core specification, specific versions of profiles are rarely tied to specific versions of the core specification, making them independent of each other. For example, there are Hands-Free Profile (HFP) 1.5 implementations using both Bluetooth 2.0 and Bluetooth 1.2 core specifications.
The way a device uses Bluetooth depends on its profile capabilities. The profiles provide standards that manufacturers follow to allow devices to use Bluetooth in the intended manner. For the Bluetooth Low Energy stack, according to Bluetooth 4.0 a special set of profiles applies.
A host Operating System can expose a basic set of profiles (namely OBEX, HID and Audio Sink) and manufacturers can add additional profiles to its driver and stack to enhance what their Bluetooth device can do. Devices such as mobile phones can expose additional profiles by installing appropriate apps.
At a minimum, each profile specification contains information on the following topics:
Dependencies on other formats
Suggested user interface formats
Specific parts of the Bluetooth protocol stack used by the profile. To perform its task, each profile uses particular options and parameters at each layer of the stack. This may include an outline of the required service record, if appropriate.
This article summarizes the current definitions of profiles defined and adopted by the Bluetooth SIG and possible applications of each profile.
Advanced Audio Distribution Profile (A2DP)
This profile defines how multimedia audio can be streamed from one device to another over a Bluetooth connec |
https://en.wikipedia.org/wiki/Eino%20Kaila | Eino Sakari Kaila (8 August 1890 – 31 July 1958) was a Finnish philosopher, critic and teacher. He worked in numerous fields including psychology (sometimes considered to be the founder of Finnish psychology), physics and theater, and attempted to find unifying principles behind various branches of human and natural sciences.
Life
Eino Kaila was born in Alajärvi, Finland. Kaila's father, Erkki Kaila, was a Protestant minister and later archbishop. He graduated from the University of Helsinki in 1910. In the 1920s he worked in the field of literary criticism and psychology as a professor at the University of Turku and is said to have been the first to introduce gestalt psychology to Finland. He was a part of the cultural circles of the time with the likes of Jean Sibelius and Frans Eemil Sillanpää. In 1916 he married the painter Anna Lovisa Snellman, who was granddaughter of Johan Vilhelm Snellman. He had University positions as lecturer in Helsinki and professor in Turku, and in 1930 he was appointed professor of theoretical philosophy at the University of Helsinki. In the 1930s, Kaila was closely associated with the Vienna Circle.
During World War II, Kaila lectured in Germany. In 1948 Kaila became a member of the Finnish Academy. He died in Kirkkonummi on 31 July 1958.
Ideas
Despite being greatly influenced by the logical positivists and critical of unempirical speculation, an aspect common to all of Kaila's work was in strive for a holistic, almost pantheistic understanding of things. He also maintained a more naturalist approach to psychology. His book Persoonallisuus (1934, Personality) was a psychological study with philosophical dimensions, in which emphasized the biological nature of psychological phenomena. During the last years of his life he attempted to construct a theory of everything in Terminalkausalität Als Die Grundlage Eines Unitarischen Naturbegriffs, but this, what was meant to be the first installment in a more extensive study, was not |
https://en.wikipedia.org/wiki/Biofunctionalisation | In the field of bioengineering, biofunctionalisation (or biofunctionalization) is the modification of a material to have biological function and/or stimulus, whether permanent or temporary, while at the same time being biologically compatible.
Various types of medical implants are designed to biofunctionalize so that they can replace or repair a defective biological function and are accepted by the host organism. |
https://en.wikipedia.org/wiki/Tetrodocain | Tetrodocain () is medical injection produced by the Korea Jangsaeng Joint Venture Company () in North Korea. The injection was first claimed to be invented by the company in 2004. According to the state-run Korean Central News Agency (KCNA), the main ingredient of the injection is tetrodotoxin, isolated from puffer poisons, and operates as an anaesthetic. It has been sold for international export on sites based in Russia and China.
KCNA described the medicine as efficacious in treating a wide range of diseases, including cancer, tuberculosis, chronic hepatitis, pancreatitis and HIV/AIDS. These claims have been deemed to be either exaggerated or false. The North Korean government also marketed its use in drug detoxification from narcotics such as opium, cocaine and heroin.
Related works
North korea released a supposed clinical research thesis about the usage of tetrodocain for anesthetics in 2015.
See also
Traditional Korean medicine
Kumdang-2
Neo-Viagra-Y.R.
Royal Blood-Fresh |
https://en.wikipedia.org/wiki/Tissue%20hydration | Tissue hydration is the process of absorbing and retaining water in biological tissues.
Plants
Land plants maintain adequate tissue hydration by means of an outer waterproof layer. In soft or green tissues, this is usually a waxy cuticle over the outer epidermis. In older, woody tissues, waterproofing chemicals are present in the secondary cell wall that limit or inhibit the flow of water. Vascular plants also possess an internal vascular system that distributes fluids throughout the plant.
Some xerophytes, such as cacti and other desert plants, have mucilage in their tissues. This is a sticky substance that holds water within the plant, reducing the rate of dehydration. Some seeds and spores remain dormant until adequate moisture is present, at which time the seed or spore begins to germinate.
Animals
Animals maintain adequate tissue hydration by means of (1) an outer skin, shell, or cuticle; (2) a fluid-filled coelom cavity; and (3) a circulatory system.
Hydration of fat free tissues, ratio of total body water to fat free body mass, is stable at 0.73 in mammals.
In humans, a significant drop in tissue hydration can lead to the medical condition of dehydration. This may result from loss of water itself, loss of electrolytes, or a loss of blood plasma. Administration of hydrational fluids as part of sound dehydration management is necessary to avoid severe complications, and in some cases, death.
Some invertebrates are able to survive extreme desiccation of their tissues by entering a state of cryptobiosis.
See also
Osmoregulation |
https://en.wikipedia.org/wiki/Zinc%20finger%20protein%20577 | Zinc finger protein 577 is a protein that in humans is encoded by the ZNF577 gene. |
https://en.wikipedia.org/wiki/Society%20of%20Neuroscientists%20of%20Africa | The Society of Neuroscientists of Africa (SONA) is a non-profit organisation registered in Nairobi, Kenya, which acts as the umbrella organisation for different neuroscience groups and societies in Africa. They organise the bi-annual SONA conference. The current president of the society is Prof. James Olukayode Olopade.
History
SONA was founded in 1993 by James Kimani. The goal of the society is to promote neuroscience research and teaching in Africa. In its history the society has organised 14 international meetings in Africa, of which the first was organized in 1993.
Conferences
1993 - Nairobi, Kenya
1995 - Marrakech, Morocco
1997 - Cape Town, South Africa
1999 - Dakar, Senegal
2001 - Nairobi, Kenya
2003 - Abuja, Nigeria
2005 - Cape Town, South Africa
2007 - Kinshasa, Democratic Republic of Congo
2009 - Faiyum, Egypt
2011 - Addis Ababa, Ethiopia
2013 - Rabat, Morocco
2015 - Durban, South Africa
2017 - Entebbe, Uganda
2019 - Lagos, Nigeria |
https://en.wikipedia.org/wiki/Bridgefy | Bridgefy is a Mexican software company with offices in Mexico and California, the United States, dedicated to developing mesh-networking technology for mobile apps. It was founded circa 2014 by Jorge Rios, after conceiving the idea while participating in a tech competition called StartupBus. Bridgefy's smartphone ad hoc network technology, apparently using Bluetooth Mesh, is licensed to other apps. The app gained popularity during protests in different countries since it can operate without Internet, using Bluetooth instead. Aware of the security issues of not using cryptography and the criticism surrounding it, Bridgefy announced in late October 2020 that they adopted the Signal protocol, in both their app and SDK, to keep information private, though security researchers have demonstrated that Bridgefy's usage of the Signal Protocol is insecure.
Usage
The app gained popularity as a communication tactic during the 2019–2020 Hong Kong protests and Citizenship Amendment Act protests in India, because it requires people who want to intercept the message to be physically close because of Bluetooth's limited range, and the ability to daisy-chain devices to send messages further than Bluetooth's range.
Security
In August 2020, researchers published a paper describing numerous attacks against the application, which allow de-anonymizing users, building social graphs of users’ interactions (both in real time and after the fact), decrypting and reading direct messages, impersonating users to anyone else on the network, completely shutting down the network, performing active man-in-the-middle attacks to read messages and even modify them.
In response to the disclosures, developers acknowledged that "no part of the Bridgefy app is encrypted now" and gave a vague promise to release a new version "encrypted with top security protocols". Later developers said they plan to switch to Signal Protocol, which is widely recognized by cryptographers and used by Signal and WhatsApp. T |
https://en.wikipedia.org/wiki/Enterprise%20encryption%20gateway | An enterprise encryption gateway (EEG) is a layer 2 encryption device, similar to VPN, that allows for strong authentication and encryption for data across a wireless medium. Unlike a residential gateway, an enterprise gateway typically has both an LAN and WLAN interface, where the EEG acts a bridge between the two. The client devices have client-side authentication/encryption software, and the EEGs are the encryption termination point in the network. Benefits of these devices include offloading the encryption duties from the access points. Autonomous access points are placed downstream from the EEGs and may act as an 802.1X authenticator. |
https://en.wikipedia.org/wiki/Docosatetraenoylethanolamide | Docosatetraenoylethanolamide (DEA) (Adrenoyl-ethanolamide) (Adrenoyl-EA) is an endogenous ethanolamide that has been shown to act on the cannabinoid (CB1) receptor. DEA is similar in structure to anandamide (AEA, a recognized endogenous ligand for the CB1 receptor), containing docosatetraenoic acid in place of arachidonic acid. While DEA has been shown to bind to the CB1 receptor with similar potency and efficacy as AEA, its role as a cannabinergic neurotransmitter is not well understood.
Docosatetraenoylethanolamide (DEA) has been found in Tropaeolum tuberosum (Mashua) and Leonotis leonurus (Wild Dagga / Lion's Tail). |
https://en.wikipedia.org/wiki/Wave%20drag | In aeronautics, wave drag is a component of the aerodynamic drag on aircraft wings and fuselage, propeller blade tips and projectiles moving at transonic and supersonic speeds, due to the presence of shock waves. Wave drag is independent of viscous effects, and tends to present itself as a sudden and dramatic increase in drag as the vehicle increases speed to the critical Mach number. It is the sudden and dramatic rise of wave drag that leads to the concept of a sound barrier.
Overview
Wave drag is a component of pressure drag due to compressibility effects. It is caused by the formation of shock waves around a body. Shock waves create a considerable amount of drag, which can result in extreme drag on the body. Although shock waves are typically associated with supersonic flow, they can form at subsonic aircraft speeds on areas of the body where local airflow accelerates to supersonic speed. The effect is typically seen on aircraft at transonic speeds (about Mach 0.8), but it is possible to notice the problem at any speed over that of the critical Mach of that aircraft. It is so pronounced that, prior to 1947, it was thought that aircraft engines would not be powerful enough to overcome the enhanced drag, or that the forces would be so great that aircraft would be at risk of breaking up in midflight. It led to the concept of a sound barrier.
Research
In 1947, studies into wave drag led to the development of perfect shapes to reduce wave drag as much as theoretically possible. For a fuselage the resulting shape was the Sears–Haack body, which suggested a perfect cross-sectional shape for any given internal volume. The von Kármán ogive was a similar shape for bodies with a blunt end, like a missile. Both were based on long narrow shapes with pointed ends, the main difference being that the ogive was pointed on only one end.
Reduction of drag
A number of new techniques developed during and just after World War II were able to dramatically reduce the magnitude |
https://en.wikipedia.org/wiki/J-CODE | J-CODE, an acronym for Joint Criminal Opioid Darknet Enforcement, is an FBI operation announced by U.S. Attorney General Jeff Sessions on January 29, 2018, in Pittsburgh, Pennsylvania which targets illegal opioid distribution on the Darknet. Given the integrity and robustness of the hidden services of the Tor anonymity network, however, sting operations, the seizure of servers, the tracking of postal deliveries, and in general the exploitation of failures of operational security are expected to be standard operating procedure. |
https://en.wikipedia.org/wiki/Henry%20P.%20H.%20Bromwell | Henry Pelham Holmes Bromwell (August 26, 1823 – January 9, 1903) was an American lawyer, politician from Illinois, and prominent Freemason. He was a lawyer and judge who served as a U.S. representative from Illinois from 1865–1869 and continued to practice law when he moved to Colorado in 1870 where he was appointed to compile the state's statutes. Bromwell was initiated into freemasonry in 1854, and he became the Grand Master of Illinois in 1864. When he moved to Colorado he became that state's first Honorary Grand Master. He developed the Free, and Accepted Architects, a new rite for Freemasonry which sought to teach its initiates the lost work of the craft embodied in Bromwell's Geometrical system. After his death, the Grand Lodge of Colorado published his work on the esoteric nature of Sacred geometry in the book Restorations of Masonic Geometry and Symbolry.
Family and education
Born in Baltimore, Maryland, Bromwell moved with his parents to Cincinnati, Ohio, in 1824, and thence to Cumberland County, Illinois, in 1836.
He attended private schools in Ohio and Illinois, including Marshall Academy (Marshall, Illinois), becoming an instructor in that academy in 1844. In 1867 he obtained an honorary degree of Master of Arts from McKendree College for his wide reputation for scholarship.
On June 20, 1858, Bromwell married Emily E. Payne. They had three children together, Emma M. Bromwell (1864–1865), Henry Pelham Payne Bromwell (1862–1881), and Henrietta Elizabeth Bromwell (1859–1946). Emma died around the same time as his wife in February 1865. Henry Jr. caught typhoid fever and died in Denver at the age of nineteen; he was studying law at the time.
After twenty years fighting sickness, Bromwell died in Denver, Colorado, January 9, 1903. He was interred in Riverside Cemetery.
Law and politics
In 1848 the family moved to Vandalia, Illinois, where Bromwell worked for his father's newspaper, The Age of Steam, and studied law. Bromwell was admitted to the bar in 1 |
https://en.wikipedia.org/wiki/Landscape%20genetics | Landscape genetics is the scientific discipline that combines population genetics and landscape ecology. It broadly encompasses any study that analyses plant or animal population genetic data in conjunction with data on the landscape features and matrix quality where the sampled population lives. This allows for the analysis of microevolutionary processes affecting the species in light of landscape spatial patterns, providing a more realistic view of how populations interact with their environments. Landscape genetics attempts to determine which landscape features are barriers to dispersal and gene flow, how human-induced landscape changes affect the evolution of populations, the source-sink dynamics of a given population, and how diseases or invasive species spread across landscapes.
Landscape genetics differs from the fields of biogeography and phylogeography by providing information at finer temporal and spatial scales (i.e., at the level of individual genetic variation within a population). Because it focuses on sampling individuals, landscape genetics has the advantage of not having to subjectively define discrete populations prior to analysis. Genetic tools are used to detect abrupt genetic differences between individuals within a population and statistical tools are used to correlate these genetic discontinuities with landscape and environmental features. The results of landscape genetics studies have potentially important applications to conservation biology and land management practices.
History
Landscape genetics emerged as its own discipline after the seminal article entitled "Landscape genetics: combining landscape ecology and population genetics" by Manel et al. appeared in the journal Trends in Ecology and Evolution in 2003. According to that article, the concept that landscape patterns affect how organisms are distributed dates back to the 18th and 19th centuries in the writings of Augustin Pyramus de Candolle and Alfred Russel Wallace. The mo |
https://en.wikipedia.org/wiki/Zinc%20finger%20protein%20280b | Zinc finger protein 280B is a protein that in humans is encoded by the ZNF280B gene.
Function
The protein encoded by this gene is a transcription factor that upregulates expression of MDM2, which negatively regulates p53 expression. This gene is highly expressed in prostate cancer cells, which leads to a reduction in p53 levels and an increase in growth of the cancer cells. Several transcript variants have been found for this gene, but only one of them is protein-coding. |
https://en.wikipedia.org/wiki/Arzel%C3%A0%E2%80%93Ascoli%20theorem | The Arzelà–Ascoli theorem is a fundamental result of mathematical analysis giving necessary and sufficient conditions to decide whether every sequence of a given family of real-valued continuous functions defined on a closed and bounded interval has a uniformly convergent subsequence. The main condition is the equicontinuity of the family of functions. The theorem is the basis of many proofs in mathematics, including that of the Peano existence theorem in the theory of ordinary differential equations, Montel's theorem in complex analysis, and the Peter–Weyl theorem in harmonic analysis and various results concerning compactness of integral operators.
The notion of equicontinuity was introduced in the late 19th century by the Italian mathematicians Cesare Arzelà and Giulio Ascoli. A weak form of the theorem was proven by , who established the sufficient condition for compactness, and by , who established the necessary condition and gave the first clear presentation of the result. A further generalization of the theorem was proven by , to sets of real-valued continuous functions with domain a compact metric space . Modern formulations of the theorem allow for the domain to be compact Hausdorff and for the range to be an arbitrary metric space. More general formulations of the theorem exist that give necessary and sufficient conditions for a family of functions from a compactly generated Hausdorff space into a uniform space to be compact in the compact-open topology; see .
Statement and first consequences
By definition, a sequence of continuous functions on an interval is uniformly bounded if there is a number such that
for every function belonging to the sequence, and every . (Here, must be independent of and .)
The sequence is said to be uniformly equicontinuous if, for every , there exists a such that
whenever for all functions in the sequence. (Here, may depend on , but not , or .)
One version of the theorem can be stated as follows:
Conside |
https://en.wikipedia.org/wiki/Cofunction | In mathematics, a function f is cofunction of a function g if f(A) = g(B) whenever A and B are complementary angles (pairs that sum to one right angle). This definition typically applies to trigonometric functions. The prefix "co-" can be found already in Edmund Gunter's Canon triangulorum (1620).
For example, sine (Latin: sinus) and cosine (Latin: cosinus, sinus complementi) are cofunctions of each other (hence the "co" in "cosine"):
The same is true of secant (Latin: secans) and cosecant (Latin: cosecans, secans complementi) as well as of tangent (Latin: tangens) and cotangent (Latin: cotangens, tangens complementi):
These equations are also known as the cofunction identities.
This also holds true for the versine (versed sine, ver) and coversine (coversed sine, cvs), the vercosine (versed cosine, vcs) and covercosine (coversed cosine, cvc), the haversine (half-versed sine, hav) and hacoversine (half-coversed sine, hcv), the havercosine (half-versed cosine, hvc) and hacovercosine (half-coversed cosine, hcc), as well as the exsecant (external secant, exs) and excosecant (external cosecant, exc):
See also
Hyperbolic functions
Lemniscatic cosine
Jacobi elliptic cosine
Cologarithm
Covariance
List of trigonometric identities |
https://en.wikipedia.org/wiki/Video%20copy%20detection | Video copy detection is the process of detecting illegally copied videos by analyzing them and comparing them to original content.
The goal of this process is to protect a video creator's intellectual property.
History
Indyk et al. produced a video copy detection theory based on the length of the film; however, it worked only for whole films without modifications. When applied to short clips of a video, Idynk et al.'s technique does not detect that the clip is a copy.
Later, Oostveen et al. introduced the concept of a fingerprint, or hash function, that creates a unique signature of the video based on its contents. This fingerprint is based on the length of the video and the brightness, as determined by splitting it into a grid. The fingerprint cannot be used to recreate the original video because it describes only certain features of its respective video.
Some time ago, B.Coskun et al. presented two robust algorithms based on discrete cosine transform.
Hampapur and Balle created an algorithm creating a global description of a piece of video based on the video's motion, color, space, and length.
To look at the color levels of the image was thought, and for this reason, Li et al. created an algorithm that examines the colors of a clip by creating a binary signature get from the histogram of every frame. This algorithm, however, returns inconsistent results in cases in which a logo is added to the video, because the insertion of the logo's color elements adds false information that can confuse the system.
Techniques
Watermarks
Watermarks are used to introduce an invisible signal into a video to ease the detection of illegal copies. This technique is widely used by photographers. Placing a watermark on a video such that it is easily seen by an audience allows the content creator to detect easily whether the image has been copied.
The limitation of watermarks is that if the original image is not watermarked, then it is not possible to know whether other ima |
https://en.wikipedia.org/wiki/Dual%20loyalty | In politics, dual loyalty is loyalty to two separate interests that potentially conflict with each other, leading to a conflict of interest.
Inherently controversial
While nearly all examples of alleged "dual loyalty" are considered highly controversial, they point to the inherent difficulty in distinguishing between what constitutes a "danger" of dual loyalty, a pair of misaligned interests, versus what might be more simply a pair of partially-aligned or even, according to the party being accused, a pair of fully-aligned interests. For example, immigrants who still have feelings of loyalty to their country of origin often insist that their two (or more) loyalties do not conflict. As Stanley A. Renshon at the Center for Immigration Studies noted,
Transnationalist interpretations
Some scholars refer to a growing trend of transnationalism and suggest that as societies become more heterogeneous and multicultural, the term "dual loyalty" had increasingly become a meaningless bromide. According to the theory of transnationalism, migration and other factors, including improved global communication, produce new forms of identity that transcend traditional notions of physical and cultural space. Nina Glick Schiller, Linda Basch, and Cristina Blanc-Szanton define a process by which immigrants "link together" their country of origin and their country of settlement.
The transnationalist view is that "dual loyalty" is a potentially-positive expression of multi-culturalism and can contribute to the diversity and strength of civil society. That view is popular in many academic circles, but others are skeptical of the idea. As one paper describes it,
Beyond its usage in particular instances, the terms "dual loyalty" and "transnationalism" continue to be the subject of much debate. As one academic wrote:
Historical examples
Other historical examples of actual or perceived "dual loyalty" include the following:
During World War II, a number of United States citizens of Japanes |
https://en.wikipedia.org/wiki/Golden%20age%20of%20physics | A golden age of physics appears to have been delineated for certain periods of progress in the physics sciences, and this includes the previous and current developments of cosmology and astronomy. Each "golden age" introduces significant advancements in theoretical and experimental methods. Discernible time periods marking a "golden age" of advancements are, for example, the development of mechanics under Galileo (1564–1642) and Isaac Newton (1642–1727). Another small epoch seen as a golden age is the unification of electricity, magnetism, and optics because of 19th century notables, including Michael Faraday, James Clerk Maxwell, and others.
Significant advancements in methods of investigation were introduced for celestial mechanics, which includes realizing a universal gravitational force, with the introduction of the telescope. Basing mechanics on experimental results was possible with the development of devices that could measure time, and tools for measuring distance. The advances in electromagnetism in the 19th century enamored physicists, as another golden age closed, and there was a reluctance to perceive further advancement. Hence, the progress of one era, termed a "golden age" has appeared to mark the completion of physics as a science. Yet, this perception has turned out to be erroneous. For example, around 1980, Stephen Hawking predicted the end of theoretical physics within 20 years. Around 2001, he amended his prediction to twenty years more from that year. Steven Weinberg predicts a unified physics by 2050. Tadeusz Lulek, Barbara Lulek, and A. Wal – the authors of a 2001 book – believed themselves to be at the beginning of a new "golden age of physics".
Paul Davies notes that whilst "many elderly scientists" may regard the first 30 years of the 20th century as a golden age of physics, historians may well, instead, regard it to be the dawning days of "the New Physics".
The golden age of physics was the 19th century. According to Emilio Segrè, in Ita |
https://en.wikipedia.org/wiki/Top%20quark%20condensate | In particle physics, the top quark condensate theory (or top condensation) is an alternative to the Standard Model fundamental Higgs field, where the Higgs boson is a composite field, composed of the top quark and its antiquark.
The top quark-antiquark pairs are bound together by a new force called topcolor, analogous to the binding of Cooper pairs in a BCS superconductor, or mesons in the strong interactions. The top quark is very heavy, with a measured mass of approximately 174 GeV (comparable to the electroweak scale), and so its Yukawa coupling is of order unity, suggesting the possibility of strong coupling dynamics at high energy scales. This model attempts to explain how the electroweak scale may match the top quark mass.
History
The idea was described by Yoichiro Nambu and subsequently developed by Miransky, Tanabashi, and Yamawaki (1989) and Bardeen, Hill, and Lindner (1990), who connected the theory to the renormalization group, and improved its predictions.
The renormalization group reveals that top quark condensation is fundamentally based upon the ‘infrared fixed point’ for the top quark Higgs-Yukawa coupling, proposed by Pendleton and Ross (1981). and Hill,
The ‘infrared’ fixed point originally predicted that the top quark would be heavy, contrary to the prevailing view of the early 1980s. Indeed, the top quark was discovered in 1995 at the large mass of 174 GeV. The infrared-fixed point implies that it is strongly coupled to the Higgs boson at very high energies, corresponding to the Landau pole of the Higgs-Yukawa coupling. At this high scale a bound-state Higgs forms, and in the ‘infrared’, the coupling relaxes to its measured value of order unity by the renormalization group. The Standard Model renormalization group fixed point prediction
is about 220 GeV, and the observed top mass is roughly 20% lower than this prediction.
The simplest top condensation models are now ruled out by the LHC discovery of the Higgs boson at a mass scale of 125 GeV. |
https://en.wikipedia.org/wiki/VCDIFF | VCDIFF is a format and an algorithm for delta encoding, described in IETF's RFC 3284. The algorithm is based on Jon Bentley and Douglas McIlroy's paper "Data Compression Using Long Common Strings" written in 1999. VCDIFF is used as one of the delta encoding algorithms in "Delta encoding in HTTP" (RFC 3229) and was employed in Google's Shared Dictionary Compression Over HTTP technology, formerly used in their Chrome browser.
Delta instructions
VCDIFF has 3 delta instructions. ADD, COPY, and RUN. ADD adds a new sequence, COPY copies from an old sequence, and RUN adds repeated data.
Implementations
Free software implementations include xdelta (version 3) and open-vcdiff.
Google's Shared Dictionary Compression Over HTTP proposal uses this algorithm, and was included in the Google Chrome browser, up to version 58.
xdelta - A tool, which is an Open Source VCDIFF delta compression implementation
google/open-vcdiff - Another Open Source VCDIFF delta compression implementation
vczip as part of vcodex and ast-open packages (also part of UWIN)
diffable - Java implementation, but some kind of original modification of VCDIFF
jvcdiff - Full decoder/encoder Java implementation of VCDIFF
vcdiff-java - another Java implementation of VCDIFF
Miscellaneous Utility Library - C# implementation, decoding only
CyanDelta - Updates CyanogenMod ROMs using Xdelta3 patches.
See also
Delta encoding
Data differencing |
https://en.wikipedia.org/wiki/Loudness%20monitoring | Loudness monitoring of programme levels is needed in radio and television broadcasting, as well as in audio post production. Traditional methods of measuring signal levels, such as the peak programme meter and VU meter, do not give the subjectively valid measure of loudness that many would argue is needed to optimise the listening experience when changing channels or swapping disks.
The need for proper loudness monitoring is apparent in the loudness war that is now found everywhere in the audio field, and the extreme compression that is now applied to programme levels.
Loudness meters
Meters have been introduced that aim to measure the human perceived loudness by taking account of the equal-loudness contours and other factors, such as audio spectrum, duration, compression and intensity. One such device was developed by CBS Laboratories in the 1980s. Complaints to broadcasters about the intrusive level of interstitials programs (advertisements, commercials) has resulted in projects to develop such meters. Based on loudness metering, many manufacturers have developed real-time audio processors that adjust the audio signal to match a specified target loudness level that preserves volume consistency at home listeners.
EBU Mode meters
In August 2010, the European Broadcasting Union published a new metering specification EBU Tech 3341, which builds on ITU-R BS.1770. To make sure meters from different manufacturers provide the same reading in LUFS units, EBU Tech 3341 specifies the EBU Mode, which includes a Momentary (400ms), Short term (3s) and Integrated (from start to stop) meter and a set of audio signals to test the meters.
See also
Audio normalization |
https://en.wikipedia.org/wiki/Inflammatory%20bowel%20disease | Inflammatory bowel disease (IBD) is a group of inflammatory conditions of the colon and small intestine, with Crohn's disease and ulcerative colitis (UC) being the principal types. Crohn's disease affects the small intestine and large intestine, as well as the mouth, esophagus, stomach and the anus, whereas ulcerative colitis primarily affects the colon and the rectum.
Signs and symptoms
In spite of Crohn's and UC being very different diseases, both may present with any of the following symptoms: abdominal pain, diarrhea, rectal bleeding, severe internal cramps/muscle spasms in the region of the pelvis and weight loss. Anemia is the most prevalent extraintestinal complication of inflammatory bowel disease. Associated complaints or diseases include arthritis, pyoderma gangrenosum, primary sclerosing cholangitis, and non-thyroidal illness syndrome (NTIS). Associations with deep vein thrombosis (DVT) and bronchiolitis obliterans organizing pneumonia (BOOP) have also been reported. Diagnosis is generally by assessment of inflammatory markers in stool followed by colonoscopy with biopsy of pathological lesions.
Causes
IBD is a complex disease which arises as a result of the interaction of environmental and genetic factors leading to immunological responses and inflammation in the intestine.
Diet
People living with IBD are very interested in diet, but little is known about the impact of diet on these patients. Recent reviews underlined the important role of nutritional counselling in IBD patients. Patients should be encouraged to adopt diets that are best supported by evidence and involve monitoring for the objective resolution of inflammation.
A 2022 study found that diets with increased intake of fruits and vegetables, reduction of processed meats and refined carbohydrates, and preference of water for hydration were associated with lower risk of active symptoms with IBD, although increased intake of fruits and vegetables alone did not reduce risk of symptoms wit |
https://en.wikipedia.org/wiki/Netgear%20WGR614L | The WGR614L (also known as the WGR614v8) is an 802.11b/g wireless network router created by Netgear. It was officially launched on June 30, 2008. The WGR614L runs an open source linux firmware and supports the installation of third party packages such as DD-WRT, Tomato, and OpenWrt.
Hardware
Broadcom BCM5354 240 MHz SoC
4 MB Flash memory
16 MB RAM
16 kB instruction cache
16 kB data cache
1000 byte pre-fetch cache
4 MB CPU cache
2 dBi gain antennas (1 internal and 1 external dipole)
802.11 b/g wireless support
Certified for use with Windows Vista
Features
Supports installation of OpenWrt, Tomato firmware, and DD-WRT
Supports Wi-Fi Protected Setup (WPS)
Automatically detects ISP type, exposed host (DMZ), MAC address authentication, URL content filtering, logs and email alerts of Internet activity
Static & dynamic routing with TCP/IP, VPN pass-through (IPsec, L2TP), NAT, PPTP, PPPoE, DHCP (client & server)
Applications
The WGR614L is designed to be used in home or business environments. It is often used in connection with third-party firmware and solutions, such as SputnikNet and Titan Hotspots. The router can also be used as a wireless client bridge (utilizing OpenWrt firmware) and as a wireless repeater bridge (using DD-WRT firmware).
External links
Press Release announcing WGR614L
Official Support Page
List Of WGR614L Resources
The WGR614L at DD-WRT.com
Using the WGR614L As A Wireless Repeater Bridge Using DD-WRT
Netgear_WGR614 Client Resources
Using the WGR614L As a Wireless Client Bridge using OpenWrt Firmware
Firmware downloads
DD-WRT Router Database (lookup WGR614L).
Old DD-WRT, Tomato and OpenWrt links over on My Open Router website.
WGR614L
Hardware routers
Linux |
https://en.wikipedia.org/wiki/Riesz%20transform | In the mathematical theory of harmonic analysis, the Riesz transforms are a family of generalizations of the Hilbert transform to Euclidean spaces of dimension d > 1. They are a type of singular integral operator, meaning that they are given by a convolution of one function with another function having a singularity at the origin. Specifically, the Riesz transforms of a complex-valued function ƒ on Rd are defined by
for j = 1,2,...,d. The constant cd is a dimensional normalization given by
where ωd−1 is the volume of the unit (d − 1)-ball. The limit is written in various ways, often as a principal value, or as a convolution with the tempered distribution
The Riesz transforms arises in the study of differentiability properties of harmonic potentials in potential theory and harmonic analysis. In particular, they arise in the proof of the Calderón-Zygmund inequality .
Multiplier properties
The Riesz transforms are given by a Fourier multiplier. Indeed, the Fourier transform of Rjƒ is given by
In this form, the Riesz transforms are seen to be generalizations of the Hilbert transform. The kernel is a distribution which is homogeneous of degree zero. A particular consequence of this last observation is that the Riesz transform defines a bounded linear operator from L2(Rd) to itself.
This homogeneity property can also be stated more directly without the aid of the Fourier transform. If σs is the dilation on Rd by the scalar s, that is σsx = sx, then σs defines an action on functions via pullback:
The Riesz transforms commute with σs:
Similarly, the Riesz transforms commute with translations. Let τa be the translation on Rd along the vector a; that is, τa(x) = x + a. Then
For the final property, it is convenient to regard the Riesz transforms as a single vectorial entity Rƒ = (R1ƒ,...,Rdƒ). Consider a rotation ρ in Rd. The rotation acts on spatial variables, and thus on functions via pullback. But it also can act on the spatial vector Rƒ. The final t |
https://en.wikipedia.org/wiki/Spiral%20of%20Theodorus | In geometry, the spiral of Theodorus (also called square root spiral, Spiral of Einstein, Pythagorean spiral, or Pythagoras's snail) is a spiral composed of right triangles, placed edge-to-edge. It was named after Theodorus of Cyrene.
Construction
The spiral is started with an isosceles right triangle, with each leg having unit length. Another right triangle is formed, an automedian right triangle with one leg being the hypotenuse of the prior triangle (with length the square root of 2) and the other leg having length of 1; the length of the hypotenuse of this second triangle is the square root of 3. The process then repeats; the th triangle in the sequence is a right triangle with the side lengths and 1, and with hypotenuse . For example, the 16th triangle has sides measuring , 1 and hypotenuse of .
History and uses
Although all of Theodorus' work has been lost, Plato put Theodorus into his dialogue Theaetetus, which tells of his work. It is assumed that Theodorus had proved that all of the square roots of non-square integers from 3 to 17 are irrational by means of the Spiral of Theodorus.
Plato does not attribute the irrationality of the square root of 2 to Theodorus, because it was well known before him. Theodorus and Theaetetus split the rational numbers and irrational numbers into different categories.
Hypotenuse
Each of the triangles' hypotenuses gives the square root of the corresponding natural number, with .
Plato, tutored by Theodorus, questioned why Theodorus stopped at . The reason is commonly believed to be that the hypotenuse belongs to the last triangle that does not overlap the figure.
Overlapping
In 1958, Kaleb Williams proved that no two hypotenuses will ever coincide, regardless of how far the spiral is continued. Also, if the sides of unit length are extended into a line, they will never pass through any of the other vertices of the total figure.
Extension
Theodorus stopped his spiral at the triangle with a hypotenuse of . If the spir |
https://en.wikipedia.org/wiki/Glycoside%20hydrolase%20family%2078 | In molecular biology, glycoside hydrolase family 78 is a family of glycoside hydrolases.
Glycoside hydrolases are a widespread group of enzymes that hydrolyse the glycosidic bond between two or more carbohydrates, or between a carbohydrate and a non-carbohydrate moiety. A classification system for glycoside hydrolases, based on sequence similarity, has led to the definition of >100 different families. This classification is available on the CAZy web site, and also discussed at CAZypedia, an online encyclopedia of carbohydrate active enzymes.
Glycoside hydrolase family 78 CAZY GH_78 includes enzymes with α-L-rhamnosidase activity. This family includes bacterial rhamnosidase A and B enzymes. L-Rhamnose is abundant in biomass as a common constituent of glycolipids and glycosides, such as plant pigments, pectic polysaccharides, gums or biosurfactants. Some rhamnosides are important bioactive compounds. For example, terpenyl glycosides, the glycosidic precursor of aromatic terpenoids, act as important flavouring substances in grapes. Other rhamnosides act as cytotoxic rhamnosylated terpenoids, as signal substances in plants or play a role in the antigenicity of pathogenic bacteria. |
https://en.wikipedia.org/wiki/2007%20New%20England%20Patriots%E2%80%93New%20York%20Giants%20game | On December 29, 2007, during the final week of the 2007 season, the New England Patriots defeated the New York Giants, 38–35, at Giants Stadium in East Rutherford, New Jersey. In what became a preview of Super Bowl XLII, the game was a close comeback win for the Patriots, giving them the first undefeated regular season since the 1972 Miami Dolphins and the only undefeated regular season since the league expanded to 16 games.
While the game was originally notable for its television coverage, the teams would later meet in Super Bowl XLII, in which the Giants won 17–14, ending the Patriots' hopes of a perfect season.
Network television coverage
When the NFL announced its 2007 regular season schedule, the game was scheduled to air exclusively on the NFL Network, as was the case with all Saturday NFL games beginning with the 2006 television contract in an attempt to boost carriage of the NFL Network by cable providers.
The game was also offered to local stations in each team's home market under a long-standing league policy for games televised on cable networks. In the case of the Patriots–Giants game, the local rights were originally sold to WCVB-TV and WMUR-TV (both ABC affiliates owned by Hearst-Argyle Television) in the Boston / Manchester market, and MyNetworkTV owned-and-operated station WWOR-TV in the New York City market.
It was a prime time matchup of regional rivals, but as the Patriots moved closer to a perfect season, the game become even more important. Therefore, the network increasingly promoted the game via television commercials on other stations. It was clear the game was one of the most anticipated in recent history, and could therefore serve as an important promotion for the NFL Network, which had tried unsuccessfully over the previous year to expand its viewership by becoming included as an "extended basic service" on the major American cable television providers such as Comcast and Time Warner Cable.
Political pressure from the Northeast to mak |
https://en.wikipedia.org/wiki/Viral%20strategies%20for%20immune%20response%20evasion | The mammalian immune system has evolved complex methods for addressing and adapting to foreign antigens. At the same time, viruses have co-evolved evasion machinery to address the many ways that host organisms attempt to eradicate them. DNA and RNA viruses use complex methods to evade immune cell detection through disruption of the Interferon Signaling Pathway, remodeling of cellular architecture, targeted gene silencing, and recognition protein cleavage.
Interferon system
The human immune system relies on a plethora of cell-cell signaling pathways to transmit information about a cell's health and microenvironment. Many of these pathways are mediated by soluble ligands, cytokines, that fit like a lock-and-key into adjacent cell surface receptors. This language of cell communication imparts both specificity and spatiotemporal control for the transmission of data.
The Interferon System is composed of a family of cytokines. Type-I Interferons, IFN-α/β, and Type-III Interferons, IFN-λ play key roles in adaptive immunity, acting as communication highways between cells infected with foreign double stranded DNA or double stranded RNA. Mammalian cells utilize specialized receptors known as Pattern Recognition Receptors(PRRs) to detect viral infection; these receptors are able to recognize pathogen-associated molecular patterns (PAMPs) inscribed in viral DNA and RNA. These pattern recognition receptors, often localized to either the cytosol or the nucleus, are responsible for notifying infected cells and initiating the secretion of interferon cytokines.
Double-stranded RNA mediated immune response
The precise role of double-stranded (ds)RNA is still widely investigated as a central player in the Interferon System. Groups have found that positive-strand RNA viruses and dsRNA viruses produced significant amounts of dsRNA, but the precise methods mammalian cells leverage to distinguish between self vs. non-self dsRNA have yet to be uncovered. Studies suggest that recogniti |
https://en.wikipedia.org/wiki/Dynamic%20Multipoint%20Virtual%20Private%20Network | Dynamic Multipoint Virtual Private Network (DMVPN) is a dynamic tunneling form of a virtual private network (VPN) supported on Cisco IOS-based routers, and Huawei AR G3 routers, and on Unix-like operating systems.
Benefits
DMVPN provides the capability for creating a dynamic-mesh VPN network without having to pre-configure (static) all possible tunnel end-point peers, including IPsec (Internet Protocol Security) and ISAKMP (Internet Security Association and Key Management Protocol) peers. DMVPN is initially configured to build out a hub-and-spoke network by statically configuring the hubs (VPN headends) on the spokes, no change in the configuration on the hub is required to accept new spokes. Using this initial hub-and-spoke network, tunnels between spokes can be dynamically built on demand (dynamic-mesh) without additional configuration on the hubs or spokes. This dynamic-mesh capability alleviates the need for any load on the hub to route data between the spoke networks.
Technologies
Next Hop Resolution Protocol,
Generic Routing Encapsulation (GRE), , or multipoint GRE if spoke-to-spoke tunnels are desired
An IP-based routing protocol, EIGRP, OSPF, RIPv2, BGP or ODR (DMVPN hub-and-spoke only).
IPsec (Internet Protocol Security) using an IPsec profile, which is associated with a virtual tunnel interface in IOS software. All traffic sent via the tunnel is encrypted per the policy configured (IPsec transform set)
Internal routing
Routing protocols such as OSPF, EIGRP v1 or v2 or BGP are generally run between the hub and spoke to allow for growth and scalability. Both EIGRP and BGP allow a higher number of supported spokes per hub.
Encryption
As with GRE tunnels, DMVPN allows for several encryption schemes (including none) for the encryption of data traversing the tunnels. For security reasons Cisco recommend that customers use AES.
Phases
DMVPN has three phases that route data differently.
Phase 1: All traffic flows from spokes to and through the hub.
|
https://en.wikipedia.org/wiki/Rotation%20%28mathematics%29 | Rotation in mathematics is a concept originating in geometry. Any rotation is a motion of a certain space that preserves at least one point. It can describe, for example, the motion of a rigid body around a fixed point. Rotation can have a sign (as in the sign of an angle): a clockwise rotation is a negative magnitude so a counterclockwise turn has a positive magnitude.
A rotation is different from other types of motions: translations, which have no fixed points, and (hyperplane) reflections, each of them having an entire -dimensional flat of fixed points in a -dimensional space.
Mathematically, a rotation is a map. All rotations about a fixed point form a group under composition called the rotation group (of a particular space). But in mechanics and, more generally, in physics, this concept is frequently understood as a coordinate transformation (importantly, a transformation of an orthonormal basis), because for any motion of a body there is an inverse transformation which if applied to the frame of reference results in the body being at the same coordinates. For example, in two dimensions rotating a body clockwise about a point keeping the axes fixed is equivalent to rotating the axes counterclockwise about the same point while the body is kept fixed. These two types of rotation are called active and passive transformations.
Related definitions and terminology
The rotation group is a Lie group of rotations about a fixed point. This (common) fixed point or center is called the center of rotation and is usually identified with the origin. The rotation group is a point stabilizer in a broader group of (orientation-preserving) motions.
For a particular rotation:
The axis of rotation is a line of its fixed points. They exist only in .
The plane of rotation is a plane that is invariant under the rotation. Unlike the axis, its points are not fixed themselves. The axis (where present) and the plane of a rotation are orthogonal.
A representation of rotations is a p |
https://en.wikipedia.org/wiki/AdS/CMT%20correspondence | In theoretical physics, anti-de Sitter/condensed matter theory correspondence is the program to apply string theory to condensed matter theory using the AdS/CFT correspondence.
Overview
Over the decades, experimental condensed matter physicists have discovered a number of exotic states of matter, including superconductors and superfluids. These states are described using the formalism of quantum field theory, but some phenomena are difficult to explain using standard field theoretic techniques. Some condensed matter theorists including Subir Sachdev hope that the AdS/CFT correspondence will make it possible to describe these systems in the language of string theory and learn more about their behavior.
So far some success has been achieved in using string theory methods to describe the transition of a superfluid to an insulator. A superfluid is a system of electrically neutral atoms that flows without any friction. Such systems are often produced in the laboratory using liquid helium, but recently experimentalists have developed new ways of producing artificial superfluids by pouring trillions of cold atoms into a lattice of criss-crossing lasers. These atoms initially behave as a superfluid, but as experimentalists increase the intensity of the lasers, they become less mobile and then suddenly transition to an insulating state. During the transition, the atoms behave in an unusual way. For example, the atoms slow to a halt at a rate that depends on the temperature and on Planck's constant, the fundamental parameter of quantum mechanics, which does not enter into the description of the other phases. This behavior has recently been understood by considering a dual description where properties of the fluid are described in terms of a higher dimensional black hole.
Criticism
Despite many physicists turning towards string-based methods to address problems in condensed matter physics, some theorists working in this area have expressed doubts about whether the AdS/CF |
https://en.wikipedia.org/wiki/Risk%E2%80%93return%20ratio | The risk-return ratio is a measure of return in terms of risk for a specific time period. The percentage return (R) for the time period is measured in a straightforward way:
where and simply refer to the price by the start and end of the time period.
The risk is measured as the percentage maximum drawdown (MDD) for the specific period:
where DDt, DDt-1, Pt and Pt-1 refer the drawdown (DD) and prices (P) at a specific point in time, t, or the time right before that, t-1.
The risk-return ratio is then defined and measured, for a specific time period, as:
Note that dividing a percentage numerator by a percentage denominator renders a single number. This RRR number is a measure of the return in terms of risk. It is fully comparable, i.e. it's possible to compare the RRR for one share with the RRR of another share, just as long as it's the same time period.
The RRR as defined here is formally the same as the so-called MER ratio, and shares some similarities with the Calmar ratio, the Sterling ratio and the Burke ratio. However, the RRR can arguably be regarded as more general than the MER ratio since it can be used for any time interval even daily or intra-day prices, while the MER ratio seems to be confined to measuring only the risk and return of a fund since inception until the current date. It is also less ad hoc than the Calmar, the Sterling and the Burke ratios.
The RRR was first defined and popularized by Dr. Richard CB Johnsson in his investment newsletter ('A Simple Risk-Return-Ratio', July 25, 2010). |
https://en.wikipedia.org/wiki/List%20of%20alpha%20emitting%20materials | The following are among the principal radioactive materials known to emit alpha particles.
209Bi, 211Bi, 212Bi, 213Bi
210Po, 211Po, 212Po, 214Po, 215Po, 216Po, 218Po
215At, 217At, 218At
218Rn, 219Rn, 220Rn, 222Rn, 226Rn
221Fr
223Ra, 224Ra, 226Ra
225Ac, 227Ac
227Th, 228Th, 229Th, 230Th, 232Th
231Pa
233U, 234U, 235U, 236U, 238U
237Np
238Pu, 239Pu, 240Pu, 244Pu
241Am
244Cm, 245Cm, 248Cm
249Cf, 252Cf
Alpha emitting
Alpha emitting |
https://en.wikipedia.org/wiki/First-player%20and%20second-player%20win | In combinatorial game theory, a two-player deterministic perfect information turn-based game is a first-player-win if with perfect play the first player to move can always force a win. Similarly, a game is second-player-win if with perfect play the second player to move can always force a win. With perfect play, if neither side can force a win, the game is a draw.
Some games with relatively small game trees have been proven to be first or second-player wins. For example, the game of nim with the classic 3–4–5 starting position is a first-player-win game. However, Nim with the 1-3-5-7 starting position is a second-player-win. The classic game of Connect Four has been mathematically proven to be first-player-win.
With perfect play, checkers has been determined to be a draw; neither player can force a win. Another example of a game which leads to a draw with perfect play is tic-tac-toe, and this includes play from any opening move.
Significant theory has been completed in the effort to solve chess. It has been speculated that there may be first-move advantage which can be detected when the game is played imperfectly (such as with all humans and all current chess engines). However, with perfect play, it remains unsolved as to whether the game is a first-player win (White), a second player win (Black), or a forced draw.
See also
Solved game
Strategy-stealing argument
Zugzwang
Determinacy
Combinatorial game theory
First-move advantage in chess |
https://en.wikipedia.org/wiki/Waterproofing | Waterproofing is the process of making an object or structure waterproof or water-resistant so that it remains relatively unaffected by water or resisting the ingress of water under specified conditions. Such items may be used in wet environments or underwater to specified depths.
Water-resistant and waterproof often refer to resistance to penetration of water in its liquid state and possibly under pressure, whereas damp proof refers to resistance to humidity or dampness. Permeation of water vapour through a material or structure is reported as a moisture vapor transmission rate (MVTR).
The hulls of boats and ships were once waterproofed by applying tar or pitch. Modern items may be waterproofed by applying water-repellent coatings or by sealing seams with gaskets or o-rings.
Waterproofing is used in reference to building structures (such as basements, decks, or wet areas), watercraft, canvas, clothing (raincoats or waders), electronic devices and paper packaging (such as cartons for liquids).
In construction
In construction, a building or structure is waterproofed with the use of membranes and coatings to protect contents and structural integrity. The waterproofing of the building envelope in construction specifications is listed under 07 - Thermal and Moisture Protection within MasterFormat 2004, by the Construction Specifications Institute, and includes roofing and waterproofing materials.
In building construction, waterproofing is a fundamental aspect of creating a building envelope, which is a controlled environment. The roof covering materials, siding, foundations, and all of the various penetrations through these surfaces must be water-resistant and sometimes waterproof. Roofing materials are generally designed to be water-resistant and shed water from a sloping roof, but in some conditions, such as ice damming and on flat roofs, the roofing must be waterproof. Many types of waterproof membrane systems are available, including felt paper or tar paper wi |
https://en.wikipedia.org/wiki/Area%20code%20900 | Area code 900 is a telephone area code in the North American Numbering Plan for premium-rate telephone numbers. Area code 900 was installed in 1971.
Premium rate services are dialed in the format 1-900-XXX-XXXX. This is often called a 900 number or a 1 900 number ("one-nine-hundred").
A call to a 900-number can result in high per-minute or per-call charges. For example, a "psychic hotline" may charge for the first minute and for each additional minute.
History
The first 900-service known to have been used in the United States, was for the "Ask President Carter" program in March 1977, for incoming calls to a nationwide talk radio broadcast featuring the newly elected President Jimmy Carter, hosted by anchorman Walter Cronkite. At that time, the intent for area code 900 was as a choke exchange—a code that blocked large numbers of simultaneous callers from jamming up the long-distance network. Numbers with the 900 area code were those which were expected to have a huge number of potential callers, and the 900 area code was screened at the local level to allow only a certain number of the callers in each area to access the nationwide long-distance network for reaching the destination number. Also, the early incarnation of 900 was not billed at premium-rate charges, but rather at regular long-distance charges based on the time of day and day of week that the call was placed. The number used for the radio program was one that was specially arranged by AT&T Corporation, CBS Radio, and the White House, to be free to the calling party. However, by 1980, the 900 area code was completely restructured by AT&T to be the premium-rate special area code which it remains today. At that time, many evening news agencies conducted "pulse polls" for $0.50 per call charges and displayed results on television. One early use was by Saturday Night Live producers for the sketch "Larry the Lobster", featuring Eddie Murphy. The comedy sketch drew nearly 500,000 calls. AT&T and the pro |
https://en.wikipedia.org/wiki/AIBO | AIBO (stylized as aibo, abbreviated as Artificial Intelligence RoBOt, homonymous with , "pal" or "partner" in Japanese) is a series of robotic dogs designed and manufactured by Sony. Sony announced a prototype Aibo in mid-1998, and the first consumer model was introduced on 11 May 1999. New models were released every year until 2006. Although most models were dogs, other inspirations included lion cubs, huskies, Jack Russell terriers, bull terrier, and space explorers. Only the ERS-7, ERS-110/111 and ERS-1000 versions were explicitly a "robotic dog", but the 210 can also be considered a dog due to its Jack Russell Terrier appearance and face.
In 2006, AIBO was added into the Carnegie Mellon University Robot Hall of Fame.
On 26 January 2006 Sony announced that it would discontinue AIBO and several other products in an effort to make the company more profitable. Sony's AIBO customer support was withdrawn gradually, with support for the final ERS-7M3 ending in March 2013.
In July 2014, Sony stopped providing repairs for AIBO products and did not provide customer support or repair for the older AIBO robots.
In November 2017, Sony announced a new generation of AIBO. The fourth generation model, ERS-1000, was launched in Japan on 11 January 2018. The second lottery sale was set on 6 February 2018.
History
The AIBO product line was developed at Sony's Computer Science Laboratory (CSL). Founded in 1990, CSL was set up to emulate the innovation center at Xerox's Palo Alto Research Center (PARC). CSL's first product was the Aperios operating system, which later formed the base software used by some AIBO models. When Nobuyuki Idei became president of Sony in 1995, he sought to adopt a digital agenda and gave greater prominence to CSL.
Dr. Toshitada Doi is credited as AIBO's original progenitor: in 1994 he had started work on robots at CSL with artificial intelligence expert Masahiro Fujita. Fujita felt that the robot's behaviors needed to "be sufficiently complex or unexp |
https://en.wikipedia.org/wiki/Faroe-Bank%20Channel%20overflow | Cold and dense water from the Nordic Seas is transported southwards as Faroe-Bank Channel overflow. This water flows from the Arctic Ocean into the North Atlantic through the Faroe-Bank Channel between the Faroe Islands and Scotland. The overflow transport is estimated to contribute to one-third (2.1±0.2 Sv, on average) of the total overflow over the Greenland-Scotland Ridge. The remaining two-third of overflow water passes through Denmark Strait (being the strongest overflow branch with an estimated transport of 3.5 Sv), the Wyville Thomson Ridge (0.3 Sv), and the Iceland-Faroe Ridge (1.1 Sv).
Faroe-Bank Channel overflow (FBCO) contributes to a large extent to the formation of North Atlantic Deep Water. Therefore, FBCO is important for water transport towards the deep parts of the North Atlantic, playing a significant role in Earth's climate system.
Faroe-Bank Channel
The Faroe-Bank Channel (FBC) is a deeply eroded channel in the Greenland-Scotland Ridge (GSR). Its primary sill, located south of the Faroe Islands, has a width of about 15 km and a maximum depth of 840 m, with very steep walls at both sides of the channel. 100 km north-west of this sill, there is a secondary sill with a maximum depth of 850 m. Faroe-Bank Channel overflow enters the FBC from the northeast, turns towards the west between the Faroe Islands and the Faroe Bank, and leaves the GSR in southwestern direction, west-southwest of the Faroe Islands.
Hydrography
The water flowing over the Greenland-Scotland Ridge through the Faroe-Bank Channel consists of a very well-mixed bottom layer, with a stratified water layer on top. The temperature of this stratified layer can get to 11 °C in the upper 100 m of the channel, with a salinity around 35.1 g/kg; between 100 and 400 m depth the temperature of the water in the stratified layer is around 8 °C, with a salinity of 35.2 g/kg. The water below 400 m, in the well-mixed layer, can be characterised as overflow water.
Definition of overflow
The mi |
https://en.wikipedia.org/wiki/Loop%20maintenance%20operations%20system | The Loop Maintenance Operations System (LMOS) is a telephone company trouble ticketing system to coordinate repairs of local loops (telephone lines). When a problem is reported by a subscriber, it is filed and relayed through the Cross Front End, which is a link from the CRSAB (Centralized Repair Service Answering Bureau) to the LMOS network. The trouble report is then sent to the Front End via the Datakit network, where a Basic Output Report is requested (usually by a screening agent or lineman). The BOR provides line information including past trouble history and MLT (Mechanized Loop Testing) tests. As LMOS is responsible for trouble reports, analysis, and similar related functions, MLT does the actual testing of customer loops. MLT hardware is located in the Repair Service Bureau. Test trunks connect MLT hardware to the telephone exchanges or wire centers, which in turn connect with the subscriber loops.
The LMOS database is a proprietary file system, designed with 11 access methods (variable index, index, hash tree, fixed partition file, etc.). This is highly tuned for the various pieces of data used by LMOS.
LMOS, which was first brought on line as a mainframe application in the 1970s, was one of the first telephone company operations support systems to be ported to the UNIX operating system. The first port of LMOS was to Digital Equipment Corporation's PDP 11/70 machines and was completed in 1981. Later versions used VAX-11/780s. Today, LMOS runs on HP-UX 11i systems. |
https://en.wikipedia.org/wiki/MariaDB | MariaDB is a community-developed, commercially supported fork of the MySQL relational database management system (RDBMS), intended to remain free and open-source software under the GNU General Public License. Development is led by some of the original developers of MySQL, who forked it due to concerns over its acquisition by Oracle Corporation in 2009.
MariaDB is intended to maintain high compatibility with MySQL, with exact matching with MySQL APIs and commands, allowing it in many cases to function as drop-in replacement for MySQL. However, new features are diverging. It includes new storage engines like Aria, ColumnStore, and MyRocks.
Its lead developer/CTO is Michael "Monty" Widenius, one of the founders of MySQL AB and the founder of Monty Program AB. On 16 January 2008, MySQL AB announced that it had agreed to be acquired by Sun Microsystems for approximately $1 billion. The acquisition completed on 26 February 2008. Sun was then bought the following year by Oracle Corporation. MariaDB is named after Widenius' younger daughter, Maria. (MySQL is named after his other daughter, My.)
Features
MariaDB Server
Licensing
The MariaDB Foundation mentions:MariaDB Server will remain Free and Open Source Software licensed under GPLv2, independent of any commercial entities.
Versioning
MariaDB version numbers follow MySQL's numbering scheme up to version 5.5. Thus, MariaDB 5.5 offers all of the MySQL 5.5 features. There exists a gap in MySQL versions between 5.1 and 5.5, while MariaDB issued 5.2 and 5.3 point releases.
Since specific new features have been developed in MariaDB, the developers decided that a major version number change was necessary.
Third-party software
MariaDB's API and protocol are compatible with those used by MySQL, plus some features to support native non-blocking operations and progress reporting. This means that all connectors, libraries and applications which work with MySQL should also work on MariaDB—whether or not they support its n |
https://en.wikipedia.org/wiki/Newtonian%20material | With regard to materials science, a material is said to be "Newtonian" if it exhibits a linear relationship between stress and strain rate.
See also
Stress
Strain
Classical mechanics |
https://en.wikipedia.org/wiki/Generalized%20geography | In computational complexity theory, generalized geography is a well-known PSPACE-complete problem.
Introduction
Geography is a children's game, where players take turns naming cities from anywhere in the world. Each city chosen must begin with the same letter that ended the previous city name. Repetition is not allowed. The game begins with an arbitrary starting city and ends when a player loses because he or she is unable to continue.
Graph model
To visualize the game, a directed graph can be constructed whose nodes are each cities of the world. An arrow is added from node N1 to node N2 if and only if the city labeling N2 starts with the letter that ending the name of the city labeling node N1. In other words, we draw an arrow from one city to another if the first can lead to the second according to the game rules. Each alternate edge in the directed graph corresponds to each player (for a two player game). The first player unable to extend the path loses. An illustration of the game (containing some cities in Michigan) is shown in the figure below.
In a generalized geography (GG) game, we replace the graph of city names with an arbitrary directed graph. The following graph is an example of a generalized geography game.
Playing the game
We define P1 as the player moving first and P2 as the player moving second and name the nodes N1 to Nn. In the above figure, P1 has a winning strategy as follows: N1 points only to nodes N2 and N3. Thus P1's first move must be one of these two choices. P1 chooses N2 (if P1 chooses N3, then P2 will choose N9 as that is the only option and P1 will lose). Next P2 chooses N4 because it is the only remaining choice. P1 now chooses N5 and P2 subsequently chooses N3 or N7. Regardless of P2's choice, P1 chooses N9 and P2 has no remaining choices and loses the game.
Computational complexity
The problem of determining which player has a winning strategy in a generalized geography game is PSPACE-complete.
Generalized geography is |
https://en.wikipedia.org/wiki/Saito%E2%80%93Kurokawa%20lift | In mathematics, the Saito–Kurokawa lift (or lifting) takes elliptic modular forms to Siegel modular forms of degree 2. The existence of this lifting was conjectured in 1977 independently by Hiroshi Saito and . Its existence was almost proved by , and and completed the proof.
Statement
The Saito–Kurokawa lift σk takes level 1 modular forms f of weight 2k − 2 to level 1 Siegel modular forms of degree 2 and weight k. The L-functions (when f is a Hecke eigenforms) are related by L(s,σk(f)) = ζ(s − k + 2)ζ(s − k + 1)L(s, f).
The Saito–Kurokawa lift can be constructed as the composition of the following three mappings:
The Shimura correspondence from level 1 modular forms of weight 2k − 2 to a space of level 4 modular forms of weight k − 1/2 in the Kohnen plus-space.
A map from the Kohnen plus-space to the space of Jacobi forms of index 1 and weight k, studied by Eichler and Zagier.
A map from the space of Jacobi forms of index 1 and weight k to the Siegel modular forms of degree 2, introduced by Maass.
The Saito–Kurokawa lift can be generalized to forms of higher level.
The image is the Spezialschar (special band), the space of Siegel modular forms whose Fourier coefficients satisfy
See also
Doi–Naganuma lifting, a similar lift to Hilbert modular forms.
Ikeda lift, a generalization to Siegel modular forms of higher degree. |
https://en.wikipedia.org/wiki/Shlomo%20Sternberg | Shlomo Zvi Sternberg (born 1936), is an American mathematician known for his work in geometry, particularly symplectic geometry and Lie theory.
Education and career
Sternberg earned his PhD in 1955 from Johns Hopkins University, with a thesis entitled "Some Problems in Discrete Nonlinear Transformations in One and Two Dimensions", supervised by Aurel Wintner.
After postdoctoral work at New York University (1956–1957) and an instructorship at University of Chicago (1957–1959), Sternberg joined the Mathematics Department at Harvard University in 1959, where he was George Putnam Professor of Pure and Applied Mathematics until 2017. Since 2017, he is Emeritus Professor at the Harvard Mathematics Department.
Among other honors, Sternberg was awarded a Guggenheim fellowship in 1974 and a honorary doctorate by the University of Mannheim in 1991. He delivered the AMS Colloquium Lecture in 1990 and the Hebrew University's Albert Einstein Memorial Lecture in 2006.
Sternberg was elected member of the American Academy of Arts and Sciences in 1969, of the National Academy of Sciences in 1986, of the Spanish Royal Academy of Sciences In 1999, and of the American Philosophical Society in 2010.
Research
Sternberg's first well-known published result, based on his PhD thesis, is known as the "Sternberg linearization theorem" which asserts that a smooth map near a hyperbolic fixed point can be made linear by a smooth change of coordinates provided that certain non-resonance conditions are satisfied. He also proved generalizations of the Birkhoff canonical form theorems for volume preserving mappings in n-dimensions and symplectic mappings, all in the smooth case.
In the 1960s Sternberg became involved with Isadore Singer in the project of revisiting Élie Cartan's papers from the early 1900s on the classification of the simple transitive infinite Lie pseudogroups, and of relating Cartan's results to recent results in the theory of G-structures and supplying rigorous (by present- |
https://en.wikipedia.org/wiki/Symplectic%20matrix | In mathematics, a symplectic matrix is a matrix with real entries that satisfies the condition
where denotes the transpose of and is a fixed nonsingular, skew-symmetric matrix. This definition can be extended to matrices with entries in other fields, such as the complex numbers, finite fields, p-adic numbers, and function fields.
Typically is chosen to be the block matrix
where is the identity matrix. The matrix has determinant and its inverse is .
Properties
Generators for symplectic matrices
Every symplectic matrix has determinant , and the symplectic matrices with real entries form a subgroup of the general linear group under matrix multiplication since being symplectic is a property stable under matrix multiplication. Topologically, this symplectic group is a connected noncompact real Lie group of real dimension , and is denoted . The symplectic group can be defined as the set of linear transformations that preserve the symplectic form of a real symplectic vector space.
This symplectic group has a distinguished set of generators, which can be used to find all possible symplectic matrices. This includes the following sets
where is the set of symmetric matrices. Then, is generated by the setp. 2
of matrices. In other words, any symplectic matrix can be constructed by multiplying matrices in and together, along with some power of .
Inverse matrix
Every symplectic matrix is invertible with the inverse matrix given by
Furthermore, the product of two symplectic matrices is, again, a symplectic matrix. This gives the set of all symplectic matrices the structure of a group. There exists a natural manifold structure on this group which makes it into a (real or complex) Lie group called the symplectic group.
Determinantal properties
It follows easily from the definition that the determinant of any symplectic matrix is ±1. Actually, it turns out that the determinant is always +1 for any field. One way to see this is through the use of the P |
https://en.wikipedia.org/wiki/Projective%20line%20over%20a%20ring | In mathematics, the projective line over a ring is an extension of the concept of projective line over a field. Given a ring A with 1, the projective line P(A) over A consists of points identified by projective coordinates. Let U be the group of units of A; pairs and from are related when there is a u in U such that and . This relation is an equivalence relation. A typical equivalence class is written U[a, b].
that is, U[a, b] is in the projective line if the ideal generated by a and b is all of A.
The projective line P(A) is equipped with a group of homographies. The homographies are expressed through use of the matrix ring over A and its group of units V as follows: If c is in Z(U), the center of U, then the group action of matrix on P(A) is the same as the action of the identity matrix. Such matrices represent a normal subgroup N of V. The homographies of P(A) correspond to elements of the quotient group .
P(A) is considered an extension of the ring A since it contains a copy of A due to the embedding
. The multiplicative inverse mapping , ordinarily restricted to the group of units U of A, is expressed by a homography on P(A):
Furthermore, for , the mapping can be extended to a homography:
Since u is arbitrary, it may be substituted for u−1.
Homographies on P(A) are called linear-fractional transformations since
Instances
Rings that are fields are most familiar: The projective line over GF(2) has three elements: , , and . Its homography group is the permutation group on these three.
The ring Z / 3Z, or GF(3), has the elements 1, 0, and −1; its projective line has the four elements , , , since both 1 and −1 are units. The homography group on this projective line has 12 elements, also described with matrices or as permutations. For a finite field GF(q), the projective line is the Galois geometry . J. W. P. Hirschfeld has described the harmonic tetrads in the projective lines for q = 4, 5, 7, 8, 9.
Over discrete rings
Consider when n is |
https://en.wikipedia.org/wiki/High-resolution%20computed%20tomography | High-resolution computed tomography (HRCT) is a type of computed tomography (CT) with specific techniques to enhance image resolution. It is used in the diagnosis of various health problems, though most commonly for lung disease, by assessing the lung parenchyma. On the other hand, HRCT of the temporal bone is used to diagnose various middle ear diseases such as otitis media, cholesteatoma, and evaluations after ear operations.
Technique
HRCT is performed using a conventional CT scanner. However, imaging parameters are chosen so as to maximize spatial resolution: a narrow slice width is used (usually 1–2 mm), a high spatial resolution image reconstruction algorithm is used, field of view is minimized, so as to minimize the size of each pixel, and other scan factors (e.g. focal spot) may be optimized for resolution at the expense of scan speed.
Depending on the suspected diagnosis, the scan may be performed in both inspiration and expiration. In inspiration images are taken in the prone position. In expiratory HRCT the scan is taken in the supine position (face up).
As HRCT's aim is to assess a generalized lung disease, the test is conventionally performed by taking thin sections which are 10–40 mm apart from each other. The result is a few images that should be representative of the lungs in general, but that cover only approximately one tenth of the lungs.
Intravenous contrast agents are not used for HRCT as the lung inherently has very high contrast (soft tissue against air), and the technique itself is unsuitable for assessment of the soft tissues and blood vessels, which are the major targets of contrast agents.
Impact of modern CT technology
The technique of HRCT was developed with relatively slow CT scanners, which did not make use of multi-detector (MDCT) technology. The parameters of scan duration, z-axis resolution and coverage were interdependent. To cover the chest in a reasonable time period with a conventional chest CT scan required thick sectio |
https://en.wikipedia.org/wiki/Havis%2C%20Inc. | Havis, Inc. is an American manufacturer of in-vehicle mobile office and prisoner transport products for private and public corporate, military and law enforcement, and enterprise fleets. Founded in Philadelphia and now headquartered in Warminster, Pennsylvania, Havis serves numerous industries including, but not limited to: public safety, military and government, utility and public works, energy services, transportation, material handling, and other mobile professions. Along with its factory in Warminster, Havis also operates a satellite office in Plymouth, Michigan.
History
Havis began in 1928 as the Havis-Shields Equipment Corporation, named for founders Dan Havis and Jim Shields. Havis-Shields supplied heavy duty automotive and electrical equipment to police departments and other areas of the public sector.
By the early 1980s, the company had branched into manufacturing, selling high-intensity scene lighting to the public safety sector. In 2009, the company announced a merger with LEDCO-ChargeGuard. Havis-Shields was renamed to Havis, Inc.
In 2011, Havis announced the sale of its Lighting Solutions product line of Kwik-Raze, Magnafire, Collins Dynamics, and Quester to R-O- M Corporation in order to focus more on its current product lines of docking stations, prisoner and K9 transport, and integrated control systems.
In 2014, Havis acquired long-time partner, Schlotter Precision Products, a manufacturer of plastic parts and molds, and formed Havis Molding.
Havis has been at its Warminster headquarters since 2002, with an on-site expansion completed in the summer of 2016.
Corporate overview
Havis is led by CEO Joe Bernert, his team of Executive Directors, and a number of small teams that focus on marketing, customer service, engineering, ISO certification, and other fields. Havis employs more than 300 workers who build and install company products.
Markets served
Havis, Inc. serves several different industries.
Public Safety
Military and Government
Uti |
https://en.wikipedia.org/wiki/Arsenic%20biochemistry | Arsenic biochemistry refers to biochemical processes that can use arsenic or its compounds, such as arsenate. Arsenic is a moderately abundant element in Earth's crust, and although many arsenic compounds are often considered highly toxic to most life, a wide variety of organoarsenic compounds are produced biologically and various organic and inorganic arsenic compounds are metabolized by numerous organisms. This pattern is general for other related elements, including selenium, which can exhibit both beneficial and deleterious effects. Arsenic biochemistry has become topical since many toxic arsenic compounds are found in some aquifers, potentially affecting many millions of people via biochemical processes.
Sources of arsenic
Organoarsenic compounds in nature
The evidence that arsenic may be a beneficial nutrient at trace levels below the background to which living organisms are normally exposed has been reviewed. Some organoarsenic compounds found in nature are arsenobetaine and arsenocholine, both being found in many marine organisms. Some As-containing nucleosides (sugar derivatives) are also known. Several of these organoarsenic compounds arise via methylation processes. For example, the mold Scopulariopsis brevicaulis produces significant amounts of trimethylarsine if inorganic arsenic is present. The organic compound arsenobetaine is found in some marine foods such as fish and algae, and also in mushrooms in larger concentrations. In clean environments, the edible mushroom species Cyanoboletus pulverulentus hyperaccumulates arsenic in concentrations reaching even 1,300 mg/kg in dry weight; cacodylic acid is the major As compound. A very unusual composition of organoarsenic compounds was found in deer truffles (Elaphomyces spp.). The average person's intake is about 10–50 µg/day. Values about 1000 µg are not unusual following consumption of fish or mushrooms; however, there is little danger in eating fish since this arsenic compound is nearly non-toxic. |
https://en.wikipedia.org/wiki/List%20of%20server-side%20JavaScript%20implementations | This is a list of server-side JavaScript implementations.
Server-side JavaScript use
Other common server-side programming languages are JavaServer Pages (JSP), Active Server Pages (ASP), Perl, PHP, Python, Ruby, ColdFusion, and others.
See also |
https://en.wikipedia.org/wiki/Cross-conjugation | Cross-conjugation is a special type of conjugation in a molecule, when in a set of three pi bonds only two pi bonds interact with each other by conjugation, while the third one is excluded from interaction. Whereas a normal conjugated system such as a polyene typically has alternating single and double bonds along consecutive atoms, a cross-conjugated system has an alkene unit bonded to one of the middle atoms of another conjugated chain through a single bond. In classical terms, one of the double-bonds branches off rather than continuing consecutively: the main chain is conjugated, and part of that same main chain is conjugated with the side group, but all parts are not conjugated together as strongly. Examples of cross-conjugation can be found in molecules such as benzophenone, , p-quinones, dendralenes, radialenes, fullerene, and Indigo dye. The type of conjugation affects reactivity and molecular electronic transitions. |
https://en.wikipedia.org/wiki/Hilbert%E2%80%93Poincar%C3%A9%20series | In mathematics, and in particular in the field of algebra, a Hilbert–Poincaré series (also known under the name Hilbert series), named after David Hilbert and Henri Poincaré, is an adaptation of the notion of dimension to the context of graded algebraic structures (where the dimension of the entire structure is often infinite). It is a formal power series in one indeterminate, say , where the coefficient of gives the dimension (or rank) of the sub-structure of elements homogeneous of degree . It is closely related to the Hilbert polynomial in cases when the latter exists; however, the Hilbert–Poincaré series describes the rank in every degree, while the Hilbert polynomial describes it only in all but finitely many degrees, and therefore provides less information. In particular the Hilbert–Poincaré series cannot be deduced from the Hilbert polynomial even if the latter exists. In good cases, the Hilbert–Poincaré series can be expressed as a rational function of its argument .
Definition
Let K be a field, and let be an -graded vector space over K, where each subspace of vectors of degree i is finite-dimensional. Then the Hilbert–Poincaré series of V is the formal power series
A similar definition can be given for an -graded R-module over any commutative ring R in which each submodule of elements homogeneous of a fixed degree n is free of finite rank; it suffices to replace the dimension by the rank. Often the graded vector space or module of which the Hilbert–Poincaré series is considered has additional structure, for instance, that of a ring, but the Hilbert–Poincaré series is independent of the multiplicative or other structure.
Example: Since there are monomials of degree k in variables (by induction, say), one can deduce that the sum of the Hilbert–Poincaré series of is the rational function .
Hilbert–Serre theorem
Suppose M is a finitely generated graded module over with an Artinian ring (e.g., a field) A. Then the Poincaré series of M is a polynomi |
https://en.wikipedia.org/wiki/Governing%20equation | The governing equations of a mathematical model describe how the values of the unknown variables (i.e. the dependent variables) change when one or more of the known (i.e. independent) variables change.
Physical systems can be modeled phenomenologically at various levels of sophistication, with each level capturing a different degree of detail about the system. A governing equation represents the most detailed and fundamental phenomenological model currently available for a given system.
For example, at the coarsest level, a beam is just a 1D curve whose torque is a function of local curvature. At a more refined level, the beam is a 2D body whose stress-tensor is a function of local strain-tensor, and strain-tensor is a function of its deformation. The equations are then a PDE system. Note that both levels of sophistication are phenomenological, but one is deeper than the other. As another example, in fluid dynamics, the Navier-Stokes equations are more refined than Euler equations.
As the field progresses and our understanding of the underlying mechanisms deepens, governing equations may be replaced or refined by new, more accurate models that better represent the system's behavior. These new governing equations can then be considered the deepest level of phenomenological model at that point in time.
Mass balance
A mass balance, also called a material balance, is an application of conservation of mass to the analysis of physical systems. It is the simplest governing equation, and it is simply a budget (balance calculation) over the quantity in question:
Differential equation
Physics
The governing equations in classical physics that are
lectured
at universities are listed below.
balance of mass
balance of (linear) momentum
balance of angular momentum
balance of energy
balance of entropy
Maxwell-Faraday equation for induced electric field
Ampére-Maxwell equation for induced magnetic field
Gauss equation for electric flux
Gauss equation for magnetic |
https://en.wikipedia.org/wiki/AG%20Neovo | Associated Industries China, Inc. (, ), known as AG Neovo, is a Taiwan-based multinational computer hardware and electronics company, headquartered in Nangang District, Taipei, Taiwan. Its main products include computer monitors, digital signage, commercial display, large format display, surveillance display, and healthcare displays. The company was established on May 18, 1978. In 1999, it transitioned its business direction to the development of electronic technology. In October of the same year, the company launched its owned brand - AG Neovo, with branch offices for Europe, Asia, and North America. Its digital photo frames and desktop computer monitors were once awarded by IF Product Design Award and Taiwan Excellence Awards.
Brand Name
AG Neovo. AG is an abbreviation of Aktiengesellschaft, which is a German term for a public limited company. Neovo is said to be a portmanteau of two Greek words, Neo and Vo.
History
Associated Industries China, Inc. was founded in 1978 in Taipei, Taiwan, producing steel intermodal containers as the revenue source.
In 1992, it was first listed on the Taiwan Stock Exchange under the ticker code 9912. In October 1999, it launched its own brand name AG Neovo.
In 2000, the company's business direction changed to the hi-tech industry. At the beginning, the business covered both computer monitors OEM and AG Neovo owned-branded product sales and marketing.
In 2003, it withdrew from the OEM business, focusing on brand owned business. The product line includes computer monitors, digital photo frames, large format displays, surveillance displays and digital signage display products.
In 2014, it set up the healthcare business unit. This product line includes dental handpieces and portable dental units.
In 2017, it set up the Solutions business unit. This product lines includes cloud-based digital signage, interactive flat panel displays and display management software.
Products
Monitor and Hardware Displays: Desktop monitors, sec |
https://en.wikipedia.org/wiki/Commutativity%20of%20conjunction | In propositional logic, the commutativity of conjunction is a valid argument form and truth-functional tautology. It is considered to be a law of classical logic. It is the principle that the conjuncts of a logical conjunction may switch places with each other, while preserving the truth-value of the resulting proposition.
Formal notation
Commutativity of conjunction can be expressed in sequent notation as:
and
where is a metalogical symbol meaning that is a syntactic consequence of , in the one case, and is a syntactic consequence of in the other, in some logical system;
or in rule form:
and
where the rule is that wherever an instance of "" appears on a line of a proof, it can be replaced with "" and wherever an instance of "" appears on a line of a proof, it can be replaced with "";
or as the statement of a truth-functional tautology or theorem of propositional logic:
and
where and are propositions expressed in some formal system.
Generalized principle
For any propositions H1, H2, ... Hn, and permutation σ(n) of the numbers 1 through n, it is the case that:
H1 H2 ... Hn
is equivalent to
Hσ(1) Hσ(2) Hσ(n).
For example, if H1 is
It is raining
H2 is
Socrates is mortal
and H3 is
2+2=4
then
It is raining and Socrates is mortal and 2+2=4
is equivalent to
Socrates is mortal and 2+2=4 and it is raining
and the other orderings of the predicates. |
https://en.wikipedia.org/wiki/Caesium%20auride | Caesium auride is the inorganic compound with the formula CsAu. It is the Cs+ salt of the unusual Au− anion.
Preparation and reactions
CsAu is obtained by heating a stoichiometric mixture of caesium and gold. The two metallic-yellow liquids react to give a transparent yellow product. Despite being a compound of two metals, CsAu lacks metallic properties since it is a salt with localized charges; it instead behaves as a semiconductor with band gap 2.6 eV.
The compound hydrolyzes readily, yielding caesium hydroxide, metallic gold, and hydrogen.
2 CsAu + 2 H2O → 2 CsOH + 2 Au + H2
The solution in liquid ammonia is brown, and the ammonia adduct is blue; the latter has ammonia molecules intercalated between layers of the CsAu crystal parallel to the (110) plane. Solutions undergo metathesis with tetramethylammonium loaded ion exchange resin to give tetramethylammonium auride. |
https://en.wikipedia.org/wiki/Semigroup%20with%20three%20elements | In abstract algebra, a semigroup with three elements is an object consisting of three elements and an associative operation defined on them. The basic example would be the three integers 0, 1, and −1, together with the operation of multiplication. Multiplication of integers is associative, and the product of any two of these three integers is again one of these three integers.
There are 18 inequivalent ways to define an associative operation on three elements: while there are, altogether, a total of 39 = 19683 different binary operations that can be defined, only 113 of these are associative, and many of these are isomorphic or antiisomorphic so that there are essentially only 18 possibilities.
One of these is C3, the cyclic group with three elements. The others all have a semigroup with two elements as subsemigroups. In the example above, the set {−1,0,1} under multiplication contains both {0,1} and {−1,1} as subsemigroups (the latter is a subgroup, C2).
Six of these are bands, meaning that all three elements are idempotent, so that the product of any element with itself is itself again. Two of these bands are commutative, therefore semilattices (one of them is the three-element totally ordered set, and the other is a three-element semilattice that is not a lattice). The other four come in anti-isomorphic pairs.
One of these non-commutative bands results from adjoining an identity element to LO2, the left zero semigroup with two elements (or, dually, to RO2, the right zero semigroup). It is sometimes called the flip-flop monoid, referring to flip-flop circuits used in electronics: the three elements can be described as "set", "reset", and "do nothing". This semigroup occurs in the Krohn–Rhodes decomposition of finite semigroups. The irreducible elements in this decomposition are the finite simple groups plus this three-element semigroup, and its subsemigroups.
There are two cyclic semigroups, one described by the equation x4 = x3, which has O2, the null semi |
https://en.wikipedia.org/wiki/International%20Journal%20of%20Algebra%20and%20Computation | The International Journal of Algebra and Computation is published by World Scientific, and contains articles on general mathematics, as well as:
Combinatorial group theory and semigroup theory
Universal algebra
Algorithmic and computational problems in algebra
Theory of automata
Formal language theory
Theory of computation
Theoretical computer science
According to the Journal Citation Reports, the journal has a 2020 impact factor of 0.719.
Abstracting and indexing
The journal is indexed in:
ISI Alerting Services
CompuMath Citation Index
Science Citation Index
Current Contents/Physical, Chemical and Earth Sciences
Mathematical Reviews
INSPEC
Zentralblatt MATH
Computer Abstracts
Mathematics journals
Academic journals established in 1991
World Scientific academic journals
English-language journals |
https://en.wikipedia.org/wiki/Plane%20joint | A plane joint (arthrodial joint, gliding joint, plane articulation) is a synovial joint which, under physiological conditions, allows only gliding movement.
Plane joints permit sliding movements in the plane of articular surfaces. The opposed surfaces of the bones are flat or almost flat, with movement limited by their tight joint capsules. Based only on their shape, plane joints can allow multiple movements, including rotation. Thus plane joints can be functionally classified as multiaxial joints. Plane joints are numerous and are nearly always small, such as the acromioclavicular joint between the acromion of the scapula and the clavicle. Typically, they are found in the wrists, ankles, the 2nd through 7th sternocostal joints, vertebral transverse and spinous processes. |
https://en.wikipedia.org/wiki/Distance%20measure | Distance measures are used in physical cosmology to give a natural notion of the distance between two objects or events in the universe. They are often used to tie some observable quantity (such as the luminosity of a distant quasar, the redshift of a distant galaxy, or the angular size of the acoustic peaks in the cosmic microwave background (CMB) power spectrum) to another quantity that is not directly observable, but is more convenient for calculations (such as the comoving coordinates of the quasar, galaxy, etc.). The distance measures discussed here all reduce to the common notion of Euclidean distance at low redshift.
In accord with our present understanding of cosmology, these measures are calculated within the context of general relativity, where the Friedmann–Lemaître–Robertson–Walker solution is used to describe the universe.
Overview
There are a few different definitions of "distance" in cosmology which are all asymptotic one to another for small redshifts. The expressions for these distances are most practical when written as functions of redshift , since redshift is always the observable. They can also be written as functions of scale factor
In the remainder of this article, the peculiar velocity is assumed to be negligible unless specified otherwise.
We first give formulas for several distance measures, and then describe them in more detail further down. Defining the "Hubble distance" as
where is the speed of light, is the Hubble parameter today, and is the dimensionless Hubble constant, all the distances are asymptotic to for small .
According to the Friedmann equations, we also define a dimensionless Hubble parameter:
Here, and are normalized values of the present radiation energy density, matter density, and "dark energy density", respectively (the latter representing the cosmological constant), and determines the curvature. The Hubble parameter at a given redshift is then .
The formula for comoving distance, which serves as the ba |
https://en.wikipedia.org/wiki/Horst%20Sachs | Horst Sachs (27 March 1927 – 25 April 2016) was a German mathematician, an expert in graph theory, a recipient of the Euler Medal (2000).
He earned the degree of Doctor of Science (Dr. rer. nat.) from the Martin-Luther-Universität Halle-Wittenberg in 1958. Following his retirement in 1992, he was professor emeritus at the Institute of Mathematics of the Technische Universität Ilmenau.
His encyclopedic book in spectral graph theory, Spectra of Graphs. Theory and Applications (with Dragos Cvetković and Michael Doob) has several editions and was translated in several languages.
Two theorems in graph theory bear his name. One of them relates the coefficients of the characteristic polynomial of a graph to certain structural features of the graph. Another one is a simple relation between the characteristic polynomials of a graph and its line graph. Sachs subgraphs are also named after Sachs. |
https://en.wikipedia.org/wiki/Synchronous%20circuit | In digital electronics, a synchronous circuit is a digital circuit in which the changes in the state of memory elements are synchronized by a clock signal. In a sequential digital logic circuit, data are stored in memory devices called flip-flops or latches. The output of a flip-flop is constant until a pulse is applied to its "clock" input, upon which the input of the flip-flop is latched into its output. In a synchronous logic circuit, an electronic oscillator called the clock generates a string (sequence) of pulses, the "clock signal". This clock signal is applied to every storage element, so in an ideal synchronous circuit, every change in the logical levels of its storage components is simultaneous. Ideally, the input to each storage element has reached its final value before the next clock occurs, so the behaviour of the whole circuit can be predicted exactly. Practically, some delay is required for each logical operation, resulting in a maximum speed limitations at which each synchronous system can run.
To make these circuits work correctly, a great deal of care is needed in the design of the clock distribution networks. Static timing analysis is often used to determine the maximum safe operating speed.
Nearly all digital circuits, and in particular nearly all CPUs, are fully synchronous circuits with a global clock.
Exceptions are often compared to fully synchronous circuits.
Exceptions include self-synchronous circuits,
globally asynchronous locally synchronous circuits,
and fully asynchronous circuits.
See also
Synchronous network
Asynchronous circuit
Moore machine
Mealy machine
Finite state machine
Sequential logic
Memory
Control unit
Arithmetic logic unit
Processor register
Application-specific integrated circuit (ASIC) |
https://en.wikipedia.org/wiki/Ruled%20variety | In algebraic geometry, a variety over a field k is ruled if it is birational to the product of the projective line with some variety over k. A variety is uniruled if it is covered by a family of rational curves. (More precisely, a variety X is uniruled if there is a variety Y and a dominant rational map Y × P1 – → X which does not factor through the projection to Y.) The concept arose from the ruled surfaces of 19th-century geometry, meaning surfaces in affine space or projective space which are covered by lines. Uniruled varieties can be considered to be relatively simple among all varieties, although there are many of them.
Properties
Every uniruled variety over a field of characteristic zero has Kodaira dimension −∞. The converse is a conjecture which is known in dimension at most 3: a variety of Kodaira dimension −∞ over a field of characteristic zero should be uniruled. A related statement is known in all dimensions: Boucksom, Demailly, Păun and Peternell showed that a smooth projective variety X over a field of characteristic zero is uniruled if and only if the canonical bundle of X is not pseudo-effective (that is, not in the closed convex cone spanned by effective divisors in the Néron-Severi group tensored with the real numbers). As a very special case, a smooth hypersurface of degree d in Pn over a field of characteristic zero is uniruled if and only if d ≤ n, by the adjunction formula. (In fact, a smooth hypersurface of degree d ≤ n in Pn is a Fano variety and hence is rationally connected, which is stronger than being uniruled.)
A variety X over an uncountable algebraically closed field k is uniruled if and only if there is a rational curve passing through every k-point of X. By contrast, there are varieties over the algebraic closure k of a finite field which are not uniruled but have a rational curve through every k-point. (The Kummer variety of any non-supersingular abelian surface over p with p odd has these properties.) It is not known whether var |
https://en.wikipedia.org/wiki/Global%20shipping%20network | The global shipping network is the worldwide network of maritime traffic. From a network science perspective ports represent nodes and routes represent lines. Transportation networks have a crucial role in today's economy, more precisely, maritime traffic is one of the most important drivers of global trade.
History
Despite estimates that 90% of world trade is transported on water, the shipping industry is probably less in the public eye than other sectors. Due to bigger vessels and economies of scale – partly also because of the appearance of standardized containers - the cost of shipping is quite cheap: a transport of a DVD player costs only $1.5 to reach Europe. Today's most crowded sea route is between China and the US, which is also quite unbalanced, as the amount of goods travelling from China to the US are four times higher than the opposite direction. Also new routes can be opened – for example Russia's Northeast Passage is a quicker way to get to Europe from China. High-tech Ports are also having ever better services. (automated terminals etc.)
Until recently one could not really know much about how these ports and kilometer long ferries are related from a network science perspective. Luckily we can have a detailed picture about how maritime traffic works. Due to a Climatological Database a visualization can be seen on the 18-19th century ocean traffic. Not only the year-to-year changes – that mostly represent strong trade relations between countries like Britain and India – but seasonal changes can be also recognized.
The network science perspective
As with every network, maritime traffic can be also viewed through a network scientist's glass. Ports can be regarded as nodes and the paths ferries travelling on are the lines. If this network is just as any other like railway or airport networks, one can have valid statements about its operation. The ocean's traffic system also has its routes, gateways, some of which functioning as a major hub or interco |
https://en.wikipedia.org/wiki/Ted%20Belytschko | Ted Bohdan Belytschko (January 13, 1943 – September 15, 2014) was an American mechanical engineer. He was Walter P. Murphy Professor and McCormick Professor of Computational Mechanics at Northwestern University. He worked in the field of computational solid mechanics and was known for development of methods like element-free Galerkin method and the Extended finite element method.
Belytschko received his B.S. in Engineering Sciences (1965) and his Ph.D. in Mechanics (1968) from the Illinois Institute of Technology. He was named in ISI Database as the fourth most cited engineering researcher in January 2004. He was also the editor of the International Journal for Numerical Methods in Engineering. He died at the age of 71 on September 15, 2014.
Awards and honors
William Prager Medal, 2011.
Member of the National Academy of Sciences (2011)
Member of the National Academy of Engineering (1992)
John von Neumann Medal of the United States Association for Computational Mechanics (2001)
Timoshenko Medal of the American Society of Mechanical Engineers (2001)
Fellow of the American Academy of Arts and Sciences (2002)
Gauss Newton Medal of the International Association for Computational Mechanics (2002)
Theodore von Karman Medal, 1999. |
https://en.wikipedia.org/wiki/X86%20assembly%20language | x86 assembly language is the name for the family of assembly languages which provide some level of backward compatibility with CPUs back to the Intel 8008 microprocessor, which was launched in April 1972. It is used to produce object code for the x86 class of processors.
Regarded as a programming language, assembly is machine-specific and low-level. Like all assembly languages, x86 assembly uses mnemonics to represent fundamental CPU instructions, or machine code. Assembly languages are most often used for detailed and time-critical applications such as small real-time embedded systems, operating-system kernels, and device drivers, but can also be used for other applications. A compiler will sometimes produce assembly code as an intermediate step when translating a high-level program into machine code.
Keyword
Reserved keywords of x86 assembly language
Mnemonics and opcodes
Each x86 assembly instruction is represented by a mnemonic which, often combined with one or more operands, translates to one or more bytes called an opcode; the NOP instruction translates to 0x90, for instance, and the HLT instruction translates to 0xF4. There are potential opcodes with no documented mnemonic which different processors may interpret differently, making a program using them behave inconsistently or even generate an exception on some processors. These opcodes often turn up in code writing competitions as a way to make the code smaller, faster, more elegant or just show off the author's prowess.
Syntax
x86 assembly language has two main syntax branches: Intel syntax and AT&T syntax. Intel syntax is dominant in the DOS and Windows world, and AT&T syntax is dominant in the Unix world, since Unix was created at AT&T Bell Labs.
Here is a summary of the main differences between Intel syntax and AT&T syntax:
Many x86 assemblers use Intel syntax, including FASM, MASM, NASM, TASM, and YASM. GAS, which originally used AT&T syntax, has supported both syntaxes since version 2.10 via t |
https://en.wikipedia.org/wiki/Sesamodil | Sesamodil is a calcium channel blocker.
Calcium channel blockers
Benzodioxoles
Benzothiazines
Lactams
Phenol ethers |
https://en.wikipedia.org/wiki/Commissural%20fiber | The commissural fibers or transverse fibers are axons that connect the two hemispheres of the brain. In contrast to commissural fibers, association fibers connect regions within the same hemisphere of the brain, and projection fibers connect each region to other parts of the brain or to the spinal cord.
Structure
The commissural fibers make up tracts that include the corpus callosum, the anterior commissure, and the posterior commissure.
Corpus callosum
The corpus callosum is the largest commissural tract in the human brain. It consists of about 200–300 million axons that connect the two cerebral hemispheres. The corpus callosum is essential to the communication between the two hemispheres.
A recent study of individuals with agenesis of the corpus callosum suggests that the corpus callosum plays a vital role in problem solving strategies, verbal processing speed, and executive performance. Specifically, the absence of a fully developed corpus callosum is shown to have a significant relationship with impaired verbal processing speed and problem solving.
Another study of individuals with multiple sclerosis provides evidence that structural and microstructural abnormalities of the corpus callosum are related to cognitive dysfunction. Particularly, verbal and visual memory, information processing speed, and executive tasks were shown to be impaired when compared to healthy individuals. Physical disabilities in multiple sclerosis patients also seem to be related to abnormalities of the corpus callosum, but not to the same extent of other cognitive functions.
Using diffusion tensor imaging, researchers have been able to produce a visualization of this network of fibers, which shows the corpus callosum has an anteroposterior topographical organization that is uniform with the cerebral cortex.
Anterior commissure
The anterior commissure (also known as the precommissure) is a tract that connects the two temporal lobes of the cerebral hemispheres across the midline, |
https://en.wikipedia.org/wiki/Svenska%20Spindlar | The book or (Swedish and Latin, respectively, for "Swedish spiders") is one of the major works of the Swedish arachnologist and entomologist Carl Alexander Clerck and was first published in Stockholm in the year 1757. It was the first comprehensive book on the spiders of Sweden and one of the first regional monographs of a group of animals worldwide. The full title of the work is – , ("Swedish spiders into their main genera separated, and as sixty and a few particular species described and with illuminated figures illustrated") and included 162 pages of text (eight pages were unpaginated) and six colour plates. It was published in Swedish, with a Latin translation printed in a slightly smaller font below the Swedish text.
Clerck described in detail 67 species of Swedish spiders, and for the first time in a zoological work consistently applied binomial nomenclature as proposed by Carl Linnaeus. Linnaeus had originally invented this system for botanical names in his 1753 work Species Plantarum, and presented it again in 1758 in the 10th edition of Systema Naturae for more than 4,000 animal species. Svenska Spindlar is the only pre-Linnaean source to be recognised as a taxonomic authority for such names.
Presentation of the spiders
Clerck explained in the last (9th of the 2nd part) chapter of his work that in contrast to previous authors he used the term "spider" in the strict sense, for animals possessing eight eyes and separated prosoma and opisthosoma, and that his concept of this group of animals did not include Opiliones (because they had two eyes and a broadly joined prosoma and opisthosoma) and other groups of arachnids.
For all spiders Clerck used a single generic name (Araneus), to which was added a specific name which consisted of only one word. Each species was presented in the Swedish text with their Latin scientific names, followed by detailed information containing the exact dates when he had found the animals, and a detailed description of eyes, |
https://en.wikipedia.org/wiki/DMDE | DMDE (DM Disk Editor and Data Recovery Software) is a data recovery and disk editing tool for hard drives and other storage media. It can work with physical devices, logical disks, disk images, as well as RAID-arrays and recovers files that have been accidentally deleted or lost due to other incidents.
DMDE is available in various editions. Free Edition (freeware) of DMDE is intended for personal use only, and allows only recovery of files located in the currently selected directory. Additionally, it allows restoring files in batches of 4,000 or less, however there's no limit on how many files can be recovered in total. DMDE paid options don't have these limitations and suggest additional features. Various reviews note that the application stands out for its attractive price, while the free option can also be sufficient in many scenarios.
DMDE is ranked among the best data recovery software and reviewed on popular technology websites, such as
TechRadar, Forbes Advisor, Softpedia. In reviews it is noted that the application does not have the simplest and most attractive interface, but it is effective, especially in complex cases.
Features
The program is able to recover files of various types with their names after deletion from the recycle bin, after formatting or other disk damages including complicated cases. DMDE can create and later open disk images to perform recovery without the risk of further damage to the drive itself. Other advanced features of DMDE include raw data search, direct disk editing capability, RAID reconstruction module, disk cloning, and partition manager.
It is supported on the operating systems Microsoft Windows, MacOS, Linux and DOS. Supported file systems include:
Windows: FAT12, FAT16, FAT32, exFAT, NTFS, NTFS5, ReFS;
Mac OS: HFS/HFS Plus, HFSX, APFS;
Linux: ext2, ext3, ext4, Btrfs.
See also
Data recovery
List of data recovery software |
https://en.wikipedia.org/wiki/Compression%20%28geology%29 | In geology, the term compression refers to a set of stress directed toward the center of a rock mass. Compressive strength refers to the maximum compressive stress that can be applied to a material before failure occurs. When the maximum compressive stress is in a horizontal orientation, thrust faulting can occur, resulting in the shortening and thickening of that portion of the crust. When the maximum compressive stress is vertical, a section of rock will often fail in normal faults, horizontally extending and vertically thinning a given layer of rock. Compressive stresses can also result in folding of rocks. Because of the large magnitudes of lithostatic stress in tectonic plates, tectonic-scale deformation is always subjected to net compressive stress.
Compressive stresses can result in a number of different features at varying scales, most notably including Folds, and Thrust faults.
See also
Gravitational compression |
https://en.wikipedia.org/wiki/Goncharov%20conjecture | In mathematics, the Goncharov conjecture is a conjecture introduced by suggesting that the cohomology of certain motivic complexes coincides with pieces of K-groups. It extends a conjecture due to .
Statement
Let F be a field. Goncharov defined the following complex called placed in degrees :
He conjectured that i-th cohomology of this complex is isomorphic to the motivic cohomology group . |
https://en.wikipedia.org/wiki/Rational%20arrival%20process | In queueing theory, a discipline within the mathematical theory of probability, a rational arrival process (RAP) is a mathematical model for the time between job arrivals to a system. It extends the concept of a Markov arrival process, allowing for dependent matrix-exponential distributed inter-arrival times.
The processes were first characterised by Asmussen and Bladt and are referred to as rational arrival processes because the inter-arrival times have a rational Laplace–Stieltjes transform.
Software
Q-MAM a MATLAB toolbox which can solve queueing systems with RAP arrivals. |
https://en.wikipedia.org/wiki/Frangipane | Frangipane ( ), is a sweet almond-flavored custard, typical in French pastry, used in a variety of ways, including cakes and such pastries as the Bakewell tart, conversation tart, Jésuite and pithivier. A French spelling from a 1674 cookbook is franchipane, with the earliest modern spelling coming from a 1732 confectioners' dictionary. Originally designated as a custard tart flavored by almonds or pistachios, it came later to designate a filling that could be used in a variety of confections and baked goods.
It is traditionally made by combining two parts of almond cream (crème d’amande) with one part pastry cream (crème pâtissière). Almond cream is made from butter, sugar, eggs, almond meal, bread flour, and rum; and pastry cream is made from whole milk, vanilla bean, cornstarch, sugar, egg yolks or whole eggs, and butter. There are many variations on both of these creams as well as on the proportion of almond cream to pastry cream in frangipane.
On Epiphany, the French cut the king cake, a round cake made of frangipane layers into slices to be distributed by a child known as le petit roi (the little king), who is usually hiding under the dining table. The cake is decorated with stars, a crown, flowers and a special bean hidden inside the cake. Whoever gets the piece of the frangipane cake with the bean is crowned "king" or "queen" for the following year.
Etymology
The word frangipane is a French term used to name products with an almond flavour. The word comes ultimately from the last name of Marquis Muzio Frangipani or Cesare Frangipani. The word first denoted the frangipani plant, from which was produced the perfume originally said to flavor frangipane. Other sources say that the name as applied to the almond custard was an homage by 16th-century Parisian chefs in name only to Frangipani, who created a jasmine-based perfume with a smell like the flowers to perfume leather gloves.
See also
List of almond dishes
List of custard desserts
List of pastries |
https://en.wikipedia.org/wiki/Desulfovibrio%20dechloracetivorans | Desulfovibrio dechloracetivorans is a bacterium. It is a Gram-negative, anaerobic, motile, short curved rod that grows by coupling the reductive dechlorination of 2-chlorophenol to the oxidation of acetate. |
https://en.wikipedia.org/wiki/Magnetosheath | The magnetosheath is the region of space between the magnetopause and the bow shock of a planet's magnetosphere. The regularly organized magnetic field generated by the planet becomes weak and irregular in the magnetosheath due to interaction with the incoming solar wind, and is incapable of fully deflecting the highly charged particles. The density of the particles in this region is considerably lower than what is found beyond the bow shock, but greater than within the magnetopause, and can be considered a transitory state.
Scientific research into the exact nature of the magnetosheath has been limited due to a longstanding misconception that it was a simple byproduct of the bow shock/magnetopause interaction and had no inherently important properties of its own. Recent studies indicate, however, that the magnetosheath is a dynamic region of turbulent plasma flow that may play an important role in the structure of the bow shock and the magnetopause, and may help to dictate the flow of energetic particles across those boundaries. Kinetic plasma instabilities may cause further complexity by generating plasma waves and energetic particle beams in the magnetosheath and foreshock regions.
The Earth's magnetosheath typically occupies the region of space approximately 10 Earth radii on the upwind (Sun-facing) side of the planet, extending significantly farther out on the downwind side due to the pressure of the solar wind. The exact location and width of the magnetosheath depends on variables such as solar activity.
See also
Earth's magnetic field
Interplanetary magnetic field (IMF)
Magnetotail
Van Allen radiation belt
Plasmasphere
Ionosphere
Space weather and heliophysics |
https://en.wikipedia.org/wiki/Chrysanthemum%20bonsai | Chrysanthemum bonsai (, ) is a Japanese art form using cultivation techniques to produce, in containers, chrysanthemum flowers that mimic the shape and scale of full size trees, called bonsai.
Cultivation and care
Bonsai cultivation and care requires techniques and tools that are specialized to support the growth and maintenance of the flowers in small containers. There are several cultivated varieties of chrysanthemum that possess the ability to be trained into many of the traditional bonsai styles associated with woody trunked trees and shrubs. But since chrysanthemum rarely grow to be old enough to have wood, deadwood bonsai techniques may also be used.
Chrysanthemums are perennials, and while it is possible to keep a chrysanthemum bonsai alive for a number of years (old wood), it is more likely that the bonsai will be 'finished' after all the blooms have faded.
The chrysanthemum bonsai artist must complete all design work in fewer than ten months. Most chrysanthemum bonsai artists in the northern latitudes of the United States start the training of their bonsai in April, and are finished by the middle of September.
Traditionally in Japan the Chrysanthemum exhibitions showcase the different bonsai forms. This takes place in autumn around the months of October and November.
Styles
Various bonsai styles exist, such as the cascade style, the clinging to a rock style, and the forest style.
See also
List of species used in bonsai |
https://en.wikipedia.org/wiki/Coniine | Coniine is a poisonous chemical compound, an alkaloid present in and isolable from poison hemlock (Conium maculatum), where its presence has been a source of significant economic, medical, and historico-cultural interest; coniine is also produced by the yellow pitcher plant (Sarracenia flava), and fool's parsley (Aethusa cynapium). Its ingestion and extended exposure are toxic to humans and all classes of livestock; its mechanism of poisoning involves disruption of the central nervous system, with death caused by respiratory paralysis. The biosynthesis of coniine contains as its penultimate step the non-enzymatic cyclisation of 5-oxooctylamine to γ-coniceine, a Schiff base differing from coniine only by its carbon-nitrogen double bond in the ring. This pathway results in natural coniine that is a mixture—a racemate—composed of two enantiomers, the stereoisomers (S)-(+)-coniine and (R)-(−)-coniine, depending on the direction taken by the chain that branches from the ring. Both enantiomers are toxic, with the (R)-enantiomer being the more biologically active and toxic of the two in general. Coniine holds a place in organic chemistry history as being the first of the important class of alkaloids to be synthesized, by Albert Ladenburg in 1886, and it has been synthesized in the laboratory in a number of unique ways through to modern times.
Hemlock poisoning has been a periodic human concern, a regular veterinary concern, and has had significant occurrences in human and cultural history. Notably, in 399 BC, Socrates was sentenced to death by drinking a coniine-containing mixture of poison hemlock.
Natural origins
Poison hemlock (Conium maculatum) contains highly toxic amounts of coniine. Its presence on farmland is an issue for livestock farmers because animals will eat it if they are not well fed or the hemlock is mixed in with pasture grass. The coniine is present in Conium maculatum as a mixture of the R-(−)- and S-(+)-enantiomers.
Coniine is also found in Sarr |
https://en.wikipedia.org/wiki/Breed | A breed is a specific group of domestic animals having homogeneous appearance (phenotype), homogeneous behavior, and/or other characteristics that distinguish it from other organisms of the same species. In literature, there exist several slightly deviating definitions. Breeds are formed through genetic isolation and either natural adaptation to the environment or selective breeding, or a combination of the two. Despite the centrality of the idea of "breeds" to animal husbandry and agriculture, no single, scientifically accepted definition of the term exists. A breed is therefore not an objective or biologically verifiable classification but is instead a term of art amongst groups of breeders who share a consensus around what qualities make some members of a given species members of a nameable subset.
Another point of view is that a breed is consistent enough in type to be logically grouped together and when mated within the group produce the same type. When bred together, individuals of the same breed pass on these predictable traits to their offspring, and this abilityknown as "breeding true"is a requirement for a breed. Plant breeds are more commonly known as cultivars. The offspring produced as a result of breeding animals of one breed with other animals of another breed are known as crossbreeds or mixed breeds. Crosses between animal or plant variants above the level of breed/cultivar (i.e. between species, subspecies, botanical variety, even different genera) are referred to as hybrids.
Breeding: selection by breeders
The breeder (or group of breeders) who initially establishes a breed does so by selecting individual animals from within a gene pool that they see as having the necessary qualities needed to enhance the breed model they are aiming for. These animals are referred to as foundation stock. Furthermore, the breeder mates the most desirable representatives of the breed from his or her point of view, aiming to pass such characteristics to their prog |
https://en.wikipedia.org/wiki/Extreme%20programming%20practices | Extreme programming (XP) is an agile software development methodology used to implement software projects. This article details the practices used in this methodology. Extreme programming has 12 practices, grouped into four areas, derived from the best practices of software engineering.
Fine scale feedback
Pair programming
Pair programming means that all the codes which is produced by two people programming on one task on one workstation. One programmer has control over the workstation and is thinking mostly about the coding in detail. The other programmer is more focused on the big picture, and is continually reviewing the code that is being produced by the first programmer. Programmers trade roles after minute to hour periods.
The pairs are not fixed; programmers switch partners frequently, so that everyone knows what everyone is doing, and everybody remains familiar with the whole system, even the parts outside their skill set. This way, pair programming also can enhance team-wide communication. (This also goes hand-in-hand with the concept of Collective Ownership).
Planning game
The main planning process within extreme programming is called the Planning Game. The game is a meeting that occurs once per iteration, typically once a week. The planning process is divided into two parts:
Release Planning: This is focused on determining what requirements are included in which near-term releases, and when they should be delivered. The customers and developers are both part of this. Release Planning consists of three phases:
Exploration Phase: In this phase the customer will provide a shortlist of high-value requirements for the system. These will be written down on user story cards.
Commitment Phase: Within the commitment phase business and developers will commit themselves to the functionality that will be included and the date of the next release.
Steering Phase: In the steering phase the plan can be adjusted, new requirements can be added and/or existing req |
https://en.wikipedia.org/wiki/Canadian%20Reference%20Materials | Canadian Reference Materials (CRM) are certified reference materials of high-quality and reliability produced by the National Metrology Institute of Canada – the National Research Council Canada. The NRC Certified Reference Materials program is operated by the Measurement Science and Standards portfolio and provides CRMs for environmental, biotoxin, food, nutritional supplement, and stable isotope analysis. The program was established in 1976 to produce CRMs for inorganic and organic marine environmental analysis and remains internationally recognized producer of CRMs.
Inorganic CRMs
NRC produces certified reference materials of biological tissues, isotopic standards, natural waters, sediments, supplements, and natural health products. With the exception of the ORMS, the river water CRM with elevated mercury, all materials contain natural levels of analytes in their native matrix.
Biological tissues
DOLT, dogfish liver for trace metals
DORM, fish protein for trace metals
LUTS, non-defatted lobster hepatopancreas for trace metals
TORT, lobster hepatopancreas for trace metals
Isotopic materials
NIMS, natural inorganic mercury standard
EMMS, isotopic methylmercury standard
Natural waters
CASS, near-shore seawater for trace metals
MOOS, seawater for nutrients
NASS, seawater for trace metals
ORMS, river water for mercury
SLEW, estuarine water for trace metals
SLRS, river water for trace metals
Sediments
HISS and MESS, marine sediment for trace metals and major constituents
PACS and SOPH, marine sediment for trace metals and major constituents
Supplements and natural health products
CACB, calcium carbonate for lead and cadmium
FEBS, otolith for trace metals
SELM, selenium-enriched yeast for selenium
Organic CRMs
In 1977, Edmonds et al. reported the identification, isolation, and synthesis of major arsenic-containing substance in sea organisms, the arsenobetaine. In 1999, NRC certified arsenobetaine in the dogfish muscle material DORM-2, which b |
https://en.wikipedia.org/wiki/OpenBSD | OpenBSD is a security-focused, free and open-source, Unix-like operating system based on the Berkeley Software Distribution (BSD). Theo de Raadt created OpenBSD in 1995 by forking NetBSD 1.0. The OpenBSD project emphasizes portability, standardization, correctness, proactive security, and integrated cryptography.
The OpenBSD project maintains portable versions of many subsystems as packages for other operating systems. Because of the project's preferred BSD license, many components are reused in proprietary and corporate-sponsored software projects. The firewall code in Apple's macOS is based on OpenBSD's PF firewall code, Android's Bionic C standard library is based on OpenBSD code, LLVM uses OpenBSD's regular expression library, and Windows 10 uses OpenSSH (OpenBSD Secure Shell) with LibreSSL.
The word "open" in the name OpenBSD refers to the availability of the operating system source code on the Internet, although the word "open" in the name OpenSSH means "OpenBSD". It also refers to the wide range of hardware platforms the system supports.
History
In December 1994, Theo de Raadt, a founding member of the NetBSD project, was asked to resign from the NetBSD core team over disagreements and conflicts with the other members of the NetBSD team. In October 1995, De Raadt founded OpenBSD, a new project forked from NetBSD 1.0. The initial release, OpenBSD 1.2, was made in July 1996, followed by OpenBSD 2.0 in October of the same year. Since then, the project has issued a release every six months, each of which is supported for one year.
On 25 July 2007, OpenBSD developer Bob Beck announced the formation of the OpenBSD Foundation, a Canadian non-profit organization formed to "act as a single point of contact for persons and organizations requiring a legal entity to deal with when they wish to support OpenBSD."
Usage statistics
It is hard to determine how widely OpenBSD is used, because the developers do not publish or collect usage statistics.
In September 20 |
https://en.wikipedia.org/wiki/Mathematical%20Programming | Mathematical Programming is a peer-reviewed scientific journal that was established in 1971 and is published by Springer Science+Business Media. It is the official journal of the Mathematical Optimization Society and consists of two series: A and B. The "A" series contains general publications, the "B" series focuses on topical mathematical programming areas. The editor-in-chief of Series A is Jon Lee (U Michigan); for Series B this is Sven Leyffer (Argonne).
History
The journal has been published by Springer since January 1999. Mathematical Programming Studies is the predecessor of the Series B part of this journal.
Abstracting and indexing
Mathematical Programming is abstracted and indexed in:
According to the Journal Citation Reports, the journal has a 2010 impact factor of 1.970. |
https://en.wikipedia.org/wiki/Tangential%20angle | In geometry, the tangential angle of a curve in the Cartesian plane, at a specific point, is the angle between the tangent line to the curve at the given point and the -axis. (Some authors define the angle as the deviation from the direction of the curve at some fixed starting point. This is equivalent to the definition given here by the addition of a constant to the angle or by rotating the curve.)
Equations
If a curve is given parametrically by , then the tangential angle at is defined (up to a multiple of ) by
Here, the prime symbol denotes the derivative with respect to . Thus, the tangential angle specifies the direction of the velocity vector , while the speed specifies its magnitude. The vector
is called the unit tangent vector, so an equivalent definition is that the tangential angle at is the angle such that is the unit tangent vector at .
If the curve is parametrized by arc length , so , then the definition simplifies to
In this case, the curvature is given by , where is taken to be positive if the curve bends to the left and negative if the curve bends to the right.
Conversely, the tangent angle at a given point equals the definite integral of curvature up to that point:
If the curve is given by the graph of a function , then we may take as the parametrization, and we may assume is between and . This produces the explicit expression
Polar tangential angle
In polar coordinates, the polar tangential angle is defined as the angle between the tangent line to the curve at the given point and ray from the origin to the point. If denotes the polar tangential angle, then , where is as above and is, as usual, the polar angle.
If the curve is defined in polar coordinates by , then the polar tangential angle at is defined (up to a multiple of ) by
.
If the curve is parametrized by arc length as , , so , then the definition becomes
.
The logarithmic spiral can be defined a curve whose polar tangential angle is constant.
See also
D |
https://en.wikipedia.org/wiki/Institute%20of%20Radio%20Engineers | The Institute of Radio Engineers (IRE) was a professional organization which existed from 1912 until December 31, 1962. On January 1, 1963, it merged with the American Institute of Electrical Engineers (AIEE) to form the Institute of Electrical and Electronics Engineers (IEEE).
Founding
Following several attempts to form a technical organization of wireless practitioners in 1908–1912, the Institute of Radio Engineers (IRE) was finally established in 1912 in New York City. Among its founding organizations were the Society of Wireless Telegraph Engineers (SWTE) and the Wireless Institute (TWI). At the time, the dominant organization of electrical engineers was the American Institute of Electrical Engineers (AIEE). Many of the founding members of IRE considered AIEE too conservative and too focused on electric power. Moreover, the founders of the IRE sought to establish an international organization (unlike the “American” AIEE), and adopted a tradition of electing some of the IRE's officers from outside the United States.
In the first half of the 20th century, radio communications had experienced great expansion, and the growing professional community of developers and operators of radio systems required standardization, research, and authoritative dissemination of new results among practitioners and researchers. To meet these needs, the IRE established professional journals (most notably the Proceedings of the IRE, established 1913 and edited for 41 years by Alfred N. Goldsmith); participated actively in all aspects of standardization and regulations of the frequency spectrum, modulation techniques, testing methods, and radio equipment; and organized regional and professional groups (starting in 1914 and 1948, respectively) for cooperation and exchange between members. The IRE was a major participant in planning of the Federal Radio Commission (established 1927; later the Federal Communications Commission), and worked in close cooperation with the National E |
https://en.wikipedia.org/wiki/Onyx%20Boox | Onyx Boox (stylized as BOOX) is a brand of e-book reader produced by Onyx International Inc, based in China. Like most e-book readers, the Boox uses electronic paper technology.
Devices
i63ML Newton
The Onyx Boox i63ML Newton (I63MLP_HD) device is the first eReader with access to Google Play. It has a 1 GHz processor, 512Mb DDR and 8 Gb internal storage memory. Build on SoC Rockchip RK2906 and Android Gingerbread 2.3.1 (API level 9, NDK 5) Linux kernel 2.6.32.27. It has 6" E-Ink Carta display 1024x758 px (14:1 contrast) with Moonight backlight.
i62ML
Onyx Boox i62ML (Moon Light) (also called "Firefly", "Angel Glow" or "Aurora" depending on the country it is sold in) is a device with 800 MHz Cortex A8 CPU, 128Mb DDR, 4Gb internal memory, a 6-inch E Ink Pearl HD infrared touch screen, with 1024×758 resolution, 16 level grey scale and built in front-light technology called Moon Light.
M92
Onyx Boox M92 is a device with a 9.7 inch E Ink Pearl screen with electromagnetic touch, 1200×825 resolution and 16 level grey scale. It supports the Hanvon stylus for touchscreen navigation and note taking. It was released in November 2011.
E43
An Android-based (2.3) smart phone and e-reader, the primary screen of which will be a 4.3 inch e-Ink display. The specs indicate it will be a tri-band device and will lack the 850 MHz band that is needed in the USA.
C65HD/C65ML
The Onyx BOOX C65 is an Android-based (2.3) device with a 6-inch E Ink HD EPD multi-touch capacitive touch screen with 1024x758 pixel resolution at 212 ppi and 16 grey levels. It comes in two versions, the C65HD "Storia" (burgundy) and the C65ML "AfterGlow" (graphite), the latter with a Modern Front-Light system. Specifications for the device include a 1 GHz Cortex A8 CPU, 512 MB RAM, 4 GB flash memory, 802.11 b/g/n WiFi, and a MicroSD card slot. Weight: 186 g (6.6 oz), Size: 170x117x8.7 mm (6.7x4.6x0.3 in).
C67ML
The Onyx BOOX C67 is an Android-based (4.2) device with a 6-inch E Ink HD EPD multi-touch capaciti |
https://en.wikipedia.org/wiki/Occam%20process | The Occam process is a solder-free, Restriction of Hazardous Substances Directive (RoHS)-compliant method for use in the manufacturing of electronic circuit boards developed by Verdant Electronics. It combines the usual two steps of the construction of printed circuit boards (PCBs) followed by the population process of placing various leaded and non-leaded electronic components into one process. The name "Occam" comes from a quotation by William of Ockham.
Overview
Electronic components are first positioned onto an adhesive layer of a temporary or permanent substrate, according to the design parameters. Then, the pre-tested, burned-in components are held firm in their positions by encapsulating them in insulating material, and the entire assembly is then inverted. The adhesive layer is then cut (after removing the temporary substrate if it exists) or drilled out over the component leads, mechanically or by laser ablation. These holes are then plated with a conductive, copper connection (a via) from the top of the layer to the component leads. If needed, other encapsulation layers of components or vias can be placed on top of each other to make multi-level circuit connections. This construction is then coated with copper where needed to provide traces. Thus, this finished circuit board can now receive a conformal coating to protect against the environment, and then be placed into an assembly housing or sent through another process for mechanical and/or electrical connections with other PCBs.
Advantages
In 2006, European, RoHS regulations prompted the research needed to move from traditional lead-based solder connection processes to a more environmentally friendly approach. Much manufacturing is currently being done with tin-based solder to address this issue. Using tin requires much higher reflow temperatures and can result in rework stages due to electric shorts caused by tin-whiskers (electrically conductive structures formed in this process) and other issues in |
https://en.wikipedia.org/wiki/Memory%20protection%20unit | A memory protection unit (MPU), is a computer hardware unit that provides memory protection. It is usually implemented as part of the central processing unit (CPU). MPU is a trimmed down version of memory management unit (MMU) providing only memory protection support. It is usually implemented in low power processors that require only memory protection and do not need the full-fledged feature of a memory management unit like virtual memory management.
Overview
The MPU allows the privileged software to define memory regions and assign memory access permission and memory attributes to each of them. Depending on the implementation of the processor, the number of supported memory regions will vary. The MPU on ARMv8-M processors supports up to 16 regions. The memory attributes define the ordering and merging behaviors of these regions, as well as caching and buffering attributes. Cache attributes can be used by internal caches, if available, and can be exported for use by system caches.
MPU monitors transactions, including instruction fetches and data accesses from the processor, which can trigger a fault exception when an access violation is detected. The main purpose of memory protection is to prevent a process from accessing memory that has not been allocated to it. This prevents a bug or malware within a process from affecting other processes, or the operating system itself.
See also
Memory management unit
Memory protection |
https://en.wikipedia.org/wiki/NTU%20method | The number of transfer units (NTU) method is used to calculate the rate of heat transfer in heat exchangers (especially counter current exchangers) when there is insufficient information to calculate the log mean temperature difference (LMTD). In heat exchanger analysis, if the fluid inlet and outlet temperatures are specified or can be determined by simple energy balance, the LMTD method can be used; but when these temperatures are not available either the NTU or the effectiveness NTU method is used.
The effectiveness-NTU method is very useful for all the flow arrangements (besides parallel flow and counterflow ones) because the effectiveness of all other types must be obtained by a numerical solution of the partial differential equations and there is no analytical equation for LMTD or effectiveness, but as a function of two variables the effectiveness for each type can be presented in a single diagram.
To define the effectiveness of a heat exchanger we need to find the maximum possible heat transfer that can be hypothetically achieved in a counter-flow heat exchanger of infinite length. Therefore one fluid will experience the maximum possible temperature difference, which is the difference of (The temperature difference between the inlet temperature of the hot stream and the inlet temperature of the cold stream). The method proceeds by calculating the heat capacity rates (i.e. mass flow rate multiplied by specific heat) and for the hot and cold fluids respectively, and denoting the smaller one as :
Where is the mass flow rate and is the fluid's specific heat capacity at constant pressure.
A quantity:
is then found, where is the maximum heat that could be transferred between the fluids per unit time. must be used as it is the fluid with the lowest heat capacity rate that would, in this hypothetical infinite length exchanger, actually undergo the maximum possible temperature change. The other fluid would change temperature more slowly along the heat exch |
https://en.wikipedia.org/wiki/Direct%20image%20functor | In mathematics, the direct image functor is a construction in sheaf theory that generalizes the global sections functor to the relative case. It is of fundamental importance in topology and algebraic geometry. Given a sheaf F defined on a topological space X and a continuous map f: X → Y, we can define a new sheaf f∗F on Y, called the direct image sheaf or the pushforward sheaf of F along f, such that the global sections of f∗F is given by the global sections of F. This assignment gives rise to a functor f∗ from the category of sheaves on X to the category of sheaves on Y, which is known as the direct image functor. Similar constructions exist in many other algebraic and geometric contexts, including that of quasi-coherent sheaves and étale sheaves on a scheme.
Definition
Let f: X → Y be a continuous map of topological spaces, and let Sh(–) denote the category of sheaves of abelian groups on a topological space. The direct image functor
sends a sheaf F on X to its direct image presheaf f∗F on Y, defined on open subsets U of Y by
This turns out to be a sheaf on Y, and is called the direct image sheaf or pushforward sheaf of F along f.
Since a morphism of sheaves φ: F → G on X gives rise to a morphism of sheaves f∗(φ): f∗(F) → f∗(G) on Y in an obvious way, we indeed have that f∗ is a functor.
Example
If Y is a point, and f: X → Y the unique continuous map, then Sh(Y) is the category Ab of abelian groups, and the direct image functor f∗: Sh(X) → Ab equals the global sections functor.
Variants
If dealing with sheaves of sets instead of sheaves of abelian groups, the same definition applies. Similarly, if f: (X, OX) → (Y, OY) is a morphism of ringed spaces, we obtain a direct image functor f∗: Sh(X,OX) → Sh(Y,OY) from the category of sheaves of OX-modules to the category of sheaves of OY-modules. Moreover, if f is now a morphism of quasi-compact and quasi-separated schemes, then f∗ preserves the property of being quasi-coherent, so we obtain the direct image |
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