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https://en.wikipedia.org/wiki/La%20petite%20mort | (; "the little death") is an expression that means "the brief loss or weakening of consciousness" and in modern usage refers specifically to "the sensation of post orgasm as likened to death."
The first attested use of the expression in English was in 1572 with the meaning of "fainting fit." It later came to mean "nervous spasm" as well. The first attested use with the meaning of "orgasm" was in 1882. In modern usage, this term has generally been interpreted to describe the post-orgasmic state of unconsciousness that certain people perceive after having some sexual experiences.
More widely, it can refer to the spiritual release that comes with orgasm or to a short period of melancholy or transcendence as a result of the expenditure of the "life force". Literary critic Roland Barthes spoke of as the chief objective of reading literature, the feeling one should get when experiencing any great literature.
The term does not always apply to sexual experiences. It can also be used when some undesired thing has happened to a person and has affected them so much that "a part of them dies inside." A literary example of this is found in Thomas Hardy's Tess of the D'Urbervilles when he uses the phrase to describe how Tess feels after she comes across a particularly gruesome omen after meeting with her own rapist:
She felt the petite mort at this unexpectedly gruesome information, and left the solitary man behind her.
The term "little death", a direct translation of , can also be used in English to essentially the same effect. Specifically, it is defined as "a state or event resembling or prefiguring death; a weakening or loss of consciousness, specifically in sleep or during an orgasm," a nearly identical definition to that of the original French. As with , the earlier attested uses are not related to sex or orgasm.
See also
Georges Bataille
Sexual headache
Dhat syndrome
Post-coital tristesse
Postorgasmic illness syndrome
Refractory period |
https://en.wikipedia.org/wiki/Cayley%20graph | In mathematics, a Cayley graph, also known as a Cayley color graph, Cayley diagram, group diagram, or color group, is a graph that encodes the abstract structure of a group. Its definition is suggested by Cayley's theorem (named after Arthur Cayley), and uses a specified set of generators for the group. It is a central tool in combinatorial and geometric group theory. The structure and symmetry of Cayley graphs makes them particularly good candidates for constructing expander graphs.
Definition
Let be a group and be a generating set of . The Cayley graph is an edge-colored directed graph constructed as follows:
Each element of is assigned a vertex: the vertex set of is identified with
Each element of is assigned a color .
For every and , there is a directed edge of color from the vertex corresponding to to the one corresponding to .
Not every convention requires that generate the group. If is not a generating set for , then is disconnected and each connected component represents a coset of the subgroup generated by .
If an element of is its own inverse, then it is typically represented by an undirected edge.
The set is often assumed to be finite, especially in geometric group theory, which corresponds to being locally finite and being finitely generated.
The set is sometimes assumed to be symmetric () and not containing the group identity element. In this case, the uncolored Cayley graph can be represented as a simple undirected graph.
Examples
Suppose that is the infinite cyclic group and the set consists of the standard generator 1 and its inverse (−1 in the additive notation); then the Cayley graph is an infinite path.
Similarly, if is the finite cyclic group of order and the set consists of two elements, the standard generator of and its inverse, then the Cayley graph is the cycle . More generally, the Cayley graphs of finite cyclic groups are exactly the circulant graphs.
The Cayley graph of the direct product of grou |
https://en.wikipedia.org/wiki/Virtual%20hosting | Virtual hosting is a method for hosting multiple domain names (with separate handling of each name) on a single server (or pool of servers). This allows one server to share its resources, such as memory and processor cycles, without requiring all services provided to use the same host name. The term virtual hosting is usually used in reference to web servers but the principles do carry over to other Internet services.
One widely used application is shared web hosting. The price for shared web hosting is lower than for a dedicated web server because many customers can be hosted on a single server. It is also very common for a single entity to want to use multiple names on the same machine so that the names can reflect services offered rather than where those services happen to be hosted.
There are two main types of virtual hosting, name-based and IP-based. Name-based virtual hosting uses the host name presented by the client. This saves IP addresses and the associated administrative overhead but the protocol being served must supply the host name at an appropriate point. In particular, there are significant difficulties using name-based virtual hosting with SSL/TLS. IP-based virtual hosting uses a separate IP address for each host name, and it can be performed with any protocol but requires a dedicated IP address per domain name served. Port-based virtual hosting is also possible in principle but is rarely used in practice because it is unfriendly to users.
Name-based and IP-based virtual hosting can be combined: a server may have multiple IP addresses and serve multiple names on some or all of those IP addresses. This technique can be useful when using SSL/TLS with wildcard certificates. For example, if a server operator had two certificates, one for *.example.com and one for *.example.net, the operator could serve foo.example.com and bar.example.com off the same IP address but would need a separate IP address for baz.example.net.
Name-based
Name-based virtual h |
https://en.wikipedia.org/wiki/Eusociality | Eusociality (from Greek εὖ eu "good" and social), the highest level of organization of sociality, is defined by the following characteristics: cooperative brood care (including care of offspring from other individuals), overlapping generations within a colony of adults, and a division of labor into reproductive and non-reproductive groups. The division of labor creates specialized behavioral groups within an animal society which are sometimes referred to as 'castes'. Eusociality is distinguished from all other social systems because individuals of at least one caste usually lose the ability to perform at least one behavior characteristic of individuals in another caste. Eusocial colonies can be viewed as superorganisms.
Eusociality exists in certain insects, crustaceans, and mammals. It is mostly observed and studied in the Hymenoptera (ants, bees, and wasps) and in Blattodea (termites). A colony has caste differences: queens and reproductive males take the roles of the sole reproducers, while soldiers and workers work together to create a living situation favorable for the brood. In addition to Hymenoptera and Blattodea, there are two known eusocial vertebrates among rodents: the naked mole-rat and the Damaraland mole-rat. Some shrimp, such as Synalpheus regalis, are also eusocial. E. O. Wilson and others have claimed that humans have evolved a weak form of eusociality, but these arguments have been disputed.
History
The term "eusocial" was introduced in 1966 by Suzanne Batra, who used it to describe nesting behavior in Halictine bees. Batra observed the cooperative behavior of the bees, males and females alike, as they took responsibility for at least one duty (i.e., burrowing, cell construction, oviposition) within the colony. The cooperativeness was essential as the activity of one labor division greatly influenced the activity of another. Eusocial colonies can be viewed as superorganisms, with individual castes being analogous to different tissue or cell typ |
https://en.wikipedia.org/wiki/RADIUS | Remote Authentication Dial-In User Service (RADIUS) is a networking protocol that provides centralized authentication, authorization, and accounting (AAA) management for users who connect and use a network service. RADIUS was developed by Livingston Enterprises in 1991 as an access server authentication and accounting protocol. It was later brought into IEEE 802 and IETF standards.
RADIUS is a client/server protocol that runs in the application layer, and can use either TCP or UDP. Network access servers, which control access to a network, usually contain a RADIUS client component that communicates with the RADIUS server. RADIUS is often the back-end of choice for 802.1X authentication. A RADIUS server is usually a background process running on UNIX or Microsoft Windows.
Protocol components
RADIUS is an AAA (authentication, authorization, and accounting) protocol that manages network access. RADIUS uses two types of packets to manage the full AAA process: Access-Request, which manages authentication and authorization; and Accounting-Request, which manages accounting. Authentication and authorization are defined in RFC 2865 while accounting is described by RFC 2866.
Authentication and authorization
The user or machine sends a request to a Network Access Server (NAS) to gain access to a particular network resource using access credentials. The credentials are passed to the NAS device via the link-layer protocol—for example, Point-to-Point Protocol (PPP) in the case of many dialup or DSL providers or posted in an HTTPS secure web form.
In turn, the NAS sends a RADIUS Access Request message to the RADIUS server, requesting authorization to grant access via the RADIUS protocol.
This request includes access credentials, typically in the form of username and password or security certificate provided by the user. Additionally, the request may contain other information which the NAS knows about the user, such as its network address or phone number, and information regar |
https://en.wikipedia.org/wiki/Wake-up%20robot%20problem | In robotics, the wake-up robot problem refers to a situation where an autonomous robot is carried to an arbitrary location and put to operation, and the robot must localize itself without any prior knowledge.
The wake-up robot problem is closely related to the kidnapped robot problem.
See also
Exploration problem
Simultaneous localization and mapping |
https://en.wikipedia.org/wiki/Public%20Health%20%28Infectious%20Diseases%29%20Regulations%201988 | The Public Health (Infectious Diseases) Regulations 1988, created by the Department of Health and Social Care, came into force on 1 October 1988 and was associated with the previous Public Health (Control of Disease) Act 1984. 24 more diseases were added, indicating exact control powers that could be applied to individual diseases.
Notifiable diseases
In addition to cholera, plague, relapsing fever, smallpox, typhus and food poisoning, the regulations of 1988 consist of 24 additional conditions:
Acute encephalitis
Acute poliomyelitis
Meningitis
Meningococcal septicaemia
Anthrax
Diphtheria
Dysentery
Paratyphoid fever
Typhoid fever
Viral hepatitis
Leprosy
Leptospirosis
Measles
Mumps
Rubella
Whooping cough
Malaria
Tetanus
Yellow fever
Ophthalmia neonatorum
Rabies
Scarlet fever
Tuberculosis
Viral haemorrhagic fever
Scotland and Northern Ireland required notification of chicken pox and legionellosis in addition to the above. |
https://en.wikipedia.org/wiki/Movat%27s%20stain | Movat's stain is a pentachrome stain originally developed by Henry Zoltan Movat (1923–1995), a Hungarian-Canadian Pathologist in Toronto in 1955 to highlight the various constituents of connective tissue, especially cardiovascular tissue, by five colors in a single stained slide. In 1972, H. K. Russell, Jr. modified the technique so as to reduce the time for staining and to increase the consistency and reliability of the staining, creating the Russell–Movat stain.
Principle
Modified Russell–Movat staining highlights numerous tissue components in histological slides. It is obtained by a mix of five stains: alcian blue, Verhoeff
hematoxylin and crocein scarlet combined with acidic fuchsine and saffron. At pH 2.5, alcian blue is fixed by electrostatic binding with the acidic mucopolysaccharides. The Verhoeff hematoxylin has a high affinity for nuclei and elastin fibers, negatively charged. The combination of crocein scarlet with acidic fuchsine stains acidophilic tissue components in red. Then, collagen and reticulin fibers are unstained by a reaction with phosphotungstic acid and stained in yellow by saffron.
Uses
Modified Russell–Movat staining is used to study the heart, blood vessels and connective tissues. It can also be used to diagnose vascular and lung diseases.
Gallery |
https://en.wikipedia.org/wiki/Reduction%20%28mathematics%29 | In mathematics, reduction refers to the rewriting of an expression into a simpler form. For example, the process of rewriting a fraction into one with the smallest whole-number denominator possible (while keeping the numerator a whole number) is called "reducing a fraction". Rewriting a radical (or "root") expression with the smallest possible whole number under the radical symbol is called "reducing a radical". Minimizing the number of radicals that appear underneath other radicals in an expression is called denesting radicals.
Algebra
In linear algebra, reduction refers to applying simple rules to a series of equations or matrices to change them into a simpler form. In the case of matrices, the process involves manipulating either the rows or the columns of the matrix and so is usually referred to as row-reduction or column-reduction, respectively. Often the aim of reduction is to transform a matrix into its "row-reduced echelon form" or "row-echelon form"; this is the goal of Gaussian elimination.
Calculus
In calculus, reduction refers to using the technique of integration by parts to evaluate integrals by reducing them to simpler forms.
Static (Guyan) reduction
In dynamic analysis, static reduction refers to reducing the number of degrees of freedom. Static reduction can also be used in finite element analysis to refer to simplification of a linear algebraic problem. Since a static reduction requires several inversion steps it is an expensive matrix operation and is prone to some error in the solution. Consider the following system of linear equations in an FEA problem:
where K and F are known and K, x and F are divided into submatrices as shown above. If F2 contains only zeros, and only x1 is desired, K can be reduced to yield the following system of equations
is obtained by writing out the set of equations as follows:
Equation () can be solved for (assuming invertibility of ):
And substituting into () gives
Thus
In a similar fashion, any row or c |
https://en.wikipedia.org/wiki/Audio%20inpainting | Audio inpainting (also known as audio interpolation) is an audio restoration task which deals with the reconstruction of missing or corrupted portions of a digital audio signal. Inpainting techniques are employed when parts of the audio have been lost due to various factors such as transmission errors, data corruption or errors during recording.
The goal of audio inpainting is to fill in the gaps (i.e., the missing portions) in the audio signal seamlessly, making the reconstructed portions indistinguishable from the original content and avoiding the introduction of audible distortions or alterations.
Many techniques have been proposed to solve the audio inpainting problem and this is usually achieved by analyzing the temporal and spectral information surrounding each missing portion of the considered audio signal.
Classic methods employ statistical models or digital signal processing algorithms to predict and synthesize the missing or damaged sections. Recent solutions, instead, take advantage of deep learning models, thanks to the growing trend of exploiting data-driven methods in the context of audio restoration.
Depending on the extent of the lost information, the inpaintining task can be divided in three categories.
Short inpainting refers to the reconstruction of few milliseconds (approximately less than 10) of missing signal, that occurs in the case of short distortions such as clicks or clipping.
In this case, the goal of the reconstruction is to recover the lost information exactly.
In long inpainting instead, with gaps in the order of hundreds of milliseconds or even seconds, this goal becomes unrealistic, since restoration techniques cannot rely on local information.
Therefore, besides providing a coherent reconstruction, the algorithms need to generate new information that has to be semantically compatible with the surrounding context (i.e., the audio signal surrounding the gaps).
The case of medium duration gaps lays between short and long inpainti |
https://en.wikipedia.org/wiki/Joe-E | Joe-E is a subset of the Java programming language intended to support programming according to object-capability discipline.
The language is notable for being an early object-capability subset language. It has influenced later subset languages, such as ADsafe and Caja/Cajita, subsets of Javascript.
It is also notable for allowing methods to be verified as functionally pure, based on their method signatures.
The restrictions imposed by the Joe-E verifier include:
Classes may not have mutable static fields, because these create global state.
Catching out-of-memory exceptions is prohibited, because doing so allows non-deterministic execution. For the same reason, clauses are not allowed.
Methods in the standard library may be blocked if they are deemed unsafe according to taming rules. For example, the constructor is blocked because it allows unrestricted access to the filesystem.
Cup of Joe is slang for coffee, and so serves as a trademark-avoiding reference to Java. Thus, the name Joe-E is intended to suggest an adaptation of ideas from the E programming language to create a variant of the Java language.
Waterken Server is written in Joe-E. |
https://en.wikipedia.org/wiki/A20%20cells | A20 cells, also called ATCC TIB-208, is a cell line originally derived from B-cell lymphoma in an old BALB/c mouse. AT20 cells are BALB/c lymphoma cells derived from spontaneous reticulum cell neoplasm. ATCC TIB-208 cells originated from B-cell lymphoma in the reticulum cell sarcoma of an elderly BALB/c mouse. A20 cells are used in medical research such as drug screening or vaccine target selection. A20 cells are also highly responsive to immunomodulatory antibodies, and are therefore used frequently in immunotherapy drug studies. |
https://en.wikipedia.org/wiki/AX.25 | AX.25 (Amateur X.25) is a data link layer protocol originally derived from layer 2 of the X.25 protocol suite and designed for use by amateur radio operators. It is used extensively on amateur packet radio networks.
AX.25 v2.0 and later occupies the data link layer, the second layer of the OSI model. It is responsible for establishing link-layer connections, transferring data encapsulated in frames between nodes, and detecting errors introduced by the communications channel. As AX.25 is a pre-OSI-model protocol, the original specification was not written to cleanly separate into OSI layers. This was rectified with version 2.0 (1984), which assumes compliance with OSI level 2.
AX.25 v2.2 (1998) added improvements to improve efficiency, especially at higher data rates. Stations can automatically negotiate payload sizes larger than the previous limitation of 256 bytes. Extended sequence numbers (7 vs. 3 bits) allow a larger window size, the number of frames that can be sent before waiting for acknowledgement. "Selective Reject" allows only the missing frames to be resent, rather than having to wastefully resend frames that have already been received successfully. Despite all these advantages, few implementations have been updated to include these improvements published more than 20 years ago. The only known complete implementation of v2.2, at this time (2020), is the Dire Wolf software TNC.
AX.25 is commonly used as the data link layer for network layer such as IPv4, with TCP used on top of that. AX.25 supports a limited form of source routing. Although it is possible to build AX.25 switches similar to the way Ethernet switches work, this has not yet been accomplished.
Specification
AX.25 does not define a physical layer implementation. In practice 1200 baud Bell 202 tones and 9600 baud G3RUH DFSK are almost exclusively used on VHF and UHF. On HF the standard transmission mode is 300 baud Bell 103 tones. At the physical layer, AX.25 defines only a "physical |
https://en.wikipedia.org/wiki/C22orf31 | C22orf31 (chromosome 22, open reading frame 31) is a protein which in humans is encoded by the C22orf31 gene. The C22orf31 mRNA transcript has an upstream in-frame stop codon, while the protein has a domain of unknown function (DUF4662) spanning the majority of the protein-coding region. The protein has orthologs with high percent similarity in mammals. The most distant orthologs are found in species of bony fish, but C22orf31 is not found in any species of birds or amphibians.
Similar to many proteins, C22orf31 is found to be highly expressed in the testes. Analysis of in vivo mature oocytes has revealed increased levels of C22orf31 while promoter analysis has identified transcription factors for C22orf31 that are active during myeloid cell differentiation.
Gene
C22orf31 is located on the minus strand of chromosome 22 at 20q12.1. The gene is 3,172 base pairs long and spans from chr22: 29,058,672 to 29,061,844. C22orf31 contains 3 exons and is also known by the aliases BK747E2.1 and HS747E2A.
Transcript
There is one transcript of C22orf31. The mRNA sequence is 1,070 base pairs long and contains an upstream in-frame stop codon from nucleotide 122–124.
Protein
General properties
The protein encoded by C22orf31 is 290 amino acids in length with a predicted molecular mass of 33kDa. The isoelectric point of the protein is 10, indicating that the pH of the protein is basic. The C22orf31 protein contains a domain of unknown function (DUF4662) from amino acid 2 – 263. The secondary and tertiary structure of this protein is not well known.
Isoforms
C22orf31 has two protein isoforms. A comparison of these isoforms is shown in the table below.
Composition
The protein derived from C22orf31 is considered somewhat rich in lysine and somewhat poor in phenylalanine compared to the composition of the average human protein. There are no positive, negative, mixed, or uncharged segments in C22orf31. There are also no transmembrane components or signal peptides in the protei |
https://en.wikipedia.org/wiki/ID-WSF | In computer networking, Identity Web Services Framework is a protocol stack that profiles WS-Security, WS-Addressing, SAML and
adds new protocol specifications of its own, such as the Discovery Service, for open market per user service
discovery, and the People Service for delegation and social networking.
Development
The ID-WSF stack was developed by the Liberty Alliance. The first release, ID-WSF 1.0 (and subsequent 1.1 and 1.2) were
released in 2003. ID-WSF1 was interoperability tested among
several vendor implementations, which received certification from the Liberty Alliance.
However, the first version of ID-WSF was not widely adopted. Perhaps the only significant adoption was by France Telecom
and the French government's Mon Service Public. Some adoption happened in Japan as well. Liberty Alliance proceeded
to create an improved version, the ID-WSF 2.0 in 2006, which included harmonization with certain WS-* technologies,
such as WS-Addressing and WS-Security. These changes were vigorously, and successfully, lobbied by Conor Cahill
of AOL (at the time). ID-WSF 2.0 interoperability certification was participated by several major league vendors, as well
as by startups and open source projects.
Since then, ID-WSF 2.0 has become the only widely accepted interoperable profile of WS-* technologies. Its strength
is essentially in narrow focus where tight enough profile for interoperability was specified. ID-WSF 2.0 interoperability
certification by Liberty Alliance was accomplished by several vendors, including some open source.
ID-WSF 2.0 has been adopted as standards base by the Finnish e-government project and by the European Commission FP7 project TAS3.
List of Implementations of ID-WSF
Sun Microsystems
Trustgenix
NEC
NTT
Symlabs SFIS
ZXID.org - the reference implementation of TAS3 - Trusted Architecture for Securely Shareable Services, with Privacy
Lasso, C library, bindings in Python, Java, Perl and PHP, GNU GPL Licence, developed by Entr'ouvert |
https://en.wikipedia.org/wiki/UQCRC2 | Cytochrome b-c1 complex subunit 2, mitochondrial (UQCRC2), also known as QCR2, UQCR2, or MC3DN5 is a protein that in humans is encoded by the UQCRC2 gene. The product of UQCRC2 is a subunit of the respiratory chain protein Ubiquinol Cytochrome c Reductase (UQCR, Complex III or Cytochrome bc1 complex), which consists of the products of one mitochondrially encoded gene, MTCYTB (mitochondrial cytochrome b) and ten nuclear genes: UQCRC1, UQCRC2, Cytochrome c1, UQCRFS1 (Rieske protein), UQCRB, "11kDa protein", UQCRH (cyt c1 Hinge protein), Rieske Protein presequence, "cyt. c1 associated protein", and "Rieske-associated protein." Defects in UQCRC2 are associated with mitochondrial complex III deficiency, nuclear, type 5.
Structure
UQCRC2 is located on the p arm of chromosome 16 in position 12.2 and has 14 exons. The UQCRC2 gene produces a 48.4 kDa protein composed of 453 amino acids. UQCRC2 belongs to the peptidase M16 family and UQCRC2/QCR2 subfamily. UQCRC2 has a transit peptide domain. Ubiquinol Cytochrome c Reductase (b-c1 complex) contains 11 subunits: 3 respiratory subunits (cytochrome b, cytochrome c1 and Rieske/UQCRFS1), 2 core proteins (UQCRC1/QCR1 and UQCRC2/QCR2) and 6 low-molecular weight proteins (UQCRH/QCR6, UQCRB/QCR7, UQCRQ/QCR8, UQCR10/QCR9, UQCR11/QCR10 and a cleavage product of Rieske/UQCRFS1). UQCRC2 is part of the hydrophobic core of the b-c1 complex and is necessary for the stabilization of Ubiquinol Cytochrome c Reductase.
Function
The protein encoded by this gene is located in the mitochondrion, where it is part of the ubiquinol-cytochrome c reductase complex (also known as complex III). This complex constitutes a part of the mitochondrial respiratory chain. The core protein UQCRC2 is required for the assembly and stabilization of the complex.
Clinical Significance
Variants of UQCRC2 have been associated with mitochondrial complex III deficiency, nuclear, type 5. Mitochondrial complex III deficiency nuclear type 5 is a disorder of the mitocho |
https://en.wikipedia.org/wiki/Sahara%20pump%20theory | The Sahara pump theory is a hypothesis that explains how flora and fauna migrated between Eurasia and Africa via a land bridge in the Levant region. It posits that extended periods of abundant rainfall lasting many thousands of years (pluvial periods) in Africa are associated with a "wet-green Sahara" phase, during which larger lakes and more rivers existed. This caused changes in the flora and fauna found in the area. Migration along the river corridor was halted when, during a desert phase 1.8–0.8 million years ago (mya), the Nile ceased to flow completely and possibly flowed only temporarily in other periods due to the geologic uplift (Nubian Swell) of the Nile River region.
Mechanism
During periods of a wet or Green Sahara, the Sahara and Arabia become a savanna grassland and African flora and fauna become common. Following inter-pluvial arid periods, the Sahara area then reverts to desert conditions, usually as a result of the retreat of the West African Monsoon southwards. Evaporation exceeds precipitation, the level of water in lakes like Lake Chad falls, and rivers become dry wadis. Flora and fauna previously widespread as a result retreat northwards to the Atlas Mountains, southwards into West Africa, or eastwards into the Nile Valley and thence either southeast to the Ethiopian Highlands and Kenya or northeast across the Sinai into Asia. This separates populations of some of the species in areas with different climates, forcing them to adapt, possibly giving rise to allopatric speciation.
Plio-Pleistocene
The Plio-Pleistocene migrations to Africa included the Caprinae in two waves at 3.2 Ma and 2.7–2.5 Ma; Nyctereutes at 2.5 Ma, and Equus at 2.3 Ma. Hippotragus migrated at 2.6 Ma from Africa to the Siwaliks of the Himalayas. Asian bovids moved to Europe and to and from Africa. The primate Theropithecus experienced contraction and its fossils are found only in Europe and Asia, while Homo and Macaca settled wide ranges.
185,000–20,000 years ago
Between ab |
https://en.wikipedia.org/wiki/English%20Broadside%20Ballad%20Archive | The English Broadside Ballad Archive (EBBA) is a digital library of 17th-century English Broadside Ballads, a project of the English Department of the University of California, Santa Barbara. The project archives ballads in multiple accessible digital formats.
History
The English Broadside Ballad Archive was created in 2003 by Patricia Fumerton, Professor of English at UCSB to digitize broadside ballads of the heyday of the 17th century. Many of these ballads are currently held in difficult to access libraries in both North America and the United Kingdom, often in fragile condition, and EBBA's aim is to make them accessible to users in a variety of digital formats. Since then, EBBA has received six Collections and Resources grants from the National Endowment for the Humanities (NEH), an NEH Digital Humanities Start-Up Grant, and Faculty Research Grants and Instructional Improvement Grants from the University of California, Santa Barbara. As of August 2015, the project has archived over 7000 of the estimated 11,000 extant broadside ballads.
Scope
As of August 2015, EBBA has archived 7,124 broadside ballads, from 20 different collections held at six different libraries worldwide. The collections range from the very well-known and recognized by name - such as those housed at the Pepys Library of Magdalene College, Cambridge - to the relatively unknown. The project has currently archived ballads from the following libraries, with partnerships in place to begin archiving ballads from several other libraries in the next two years.
Holding Libraries and Named Collections
British Library
Roxburghe Ballads
Glasgow University Library
Euing Collection
Houghton Library of Harvard University
Huth Collection
Huntington Library
Bindley Collection
Bridgewater Collection
Britwell Collection
Magdalene College, Cambridge
Pepys Ballads
National Library of Scotland
Crawford Collection
Rosebery Collection
Archival Formats
In addition to cataloging all of its holdin |
https://en.wikipedia.org/wiki/Sound%20level%20meter | A sound level meter (also called sound pressure level meter (SPL)) is used for acoustic measurements. It is commonly a hand-held instrument with a microphone. The best type of microphone for sound level meters is the condenser microphone, which combines precision with stability and reliability. The diaphragm of the microphone responds to changes in air pressure caused by sound waves. That is why the instrument is sometimes referred to as a sound pressure level meter (SPL). This movement of the diaphragm, i.e. the sound pressure (unit pascal, Pa), is converted into an electrical signal (unit volt, V). While describing sound in terms of sound pressure, a logarithmic conversion is usually applied and the sound pressure level is stated instead, in decibels (dB), with 0 dB SPL equal to 20 micropascals.
A microphone is distinguishable by the voltage value produced when a known, constant root mean square sound pressure is applied. This is known as microphone sensitivity. The instrument needs to know the sensitivity of the particular microphone being used. Using this information, the instrument is able to accurately convert the electrical signal back to sound pressure, and display the resulting sound pressure level (unit decibel, dB).
Sound level meters are commonly used in noise pollution studies for the quantification of different kinds of noise, especially for industrial, environmental, mining and aircraft noise. The current international standard that specifies sound level meter functionality and performances is the IEC 61672-1:2013. However, the reading from a sound level meter does not correlate well to human-perceived loudness, which is better measured by a loudness meter. Specific loudness is a compressive nonlinearity and varies at certain levels and at certain frequencies. These metrics can also be calculated in a number of different ways.
The world's first hand-held and transistorized sound level meter, was released in 1960 and developed by the Danish company |
https://en.wikipedia.org/wiki/Adaptive%20Huffman%20coding | Adaptive Huffman coding (also called Dynamic Huffman coding) is an adaptive coding technique based on Huffman coding. It permits building the code as the symbols are being transmitted, having no initial knowledge of source distribution, that allows one-pass encoding and adaptation to changing conditions in data.
The benefit of one-pass procedure is that the source can be encoded in real time, though it becomes more sensitive to transmission errors, since just a single loss ruins the whole code, requiring error detection and correction.
Algorithms
There are a number of implementations of this method, the most notable are FGK (Faller-Gallager-Knuth) and Vitter algorithm.
FGK Algorithm
It is an online coding technique based on Huffman coding. Having no initial knowledge of occurrence frequencies, it permits dynamically adjusting the Huffman's tree as data are being transmitted. In a FGK Huffman tree, a special external node, called 0-node, is used to identify a newly coming character. That is, whenever new data is encountered, output the path to the 0-node followed by the data. For a past-coming character, just output the path of the data in the current Huffman's tree. Most importantly, we have to adjust the FGK Huffman tree if necessary, and finally update the frequency of related nodes. As the frequency of a datum is increased, the sibling property of the Huffman's tree may be broken. The adjustment is triggered for this reason. It is accomplished by consecutive swappings of nodes, subtrees, or both. The data node is swapped with the highest-ordered node of the same frequency in the Huffman's tree, (or the subtree rooted at the highest-ordered node). All ancestor nodes of the node should also be processed in the same manner.
Since the FGK Algorithm has some drawbacks about the node-or-subtree swapping, Vitter proposed another algorithm to improve it.
Vitter algorithm
Some important terminologies & constraints :-
Implicit Numbering : It simply means that nodes |
https://en.wikipedia.org/wiki/Reed%20receiver | A reed receiver or tuned reed receiver (US) was a form of multi-channel signal decoder used for early radio control systems. It uses a simple electromechanical device or 'resonant reed' to demodulate the signal, in effect a receive-only modem. The encoding used is a simple form of frequency-shift keying.
These decoders appeared in the 1950s and were used into the early 1970s. Early transistor systems were in use in parallel to them, but they were finally displaced by the appearance of affordable digital proportional systems, based on early integrated circuits. These had the advantage of proportional control.
Operation
The decoder of the reed receiver is based on the 'resonant reed' unit. This comprises a number of vibrating metal reeds, each one having a tuned vibration frequency like a tuning fork. These reeds are manufactured from a single tapered sheet of iron or steel, giving a comb of reeds of varying length. This resembles the comb used to sound musical notes in a music box. Like a music box, the length of each reed affects its resonant frequency. The reeds are powered magnetically, by a single solenoid coil and an iron core wrapped between the ends of the reeds.
A reed's resonant frequency is a mid-range audible frequency of perhaps 300 Hz. The solenoid is driven by the output of the radio control receiver, which is an audio tone or tones. If the receiver output contains the appropriate tone for the resonant frequency of a reed, that reed would be made to vibrate. As the reed vibrates, it touches a contact screw above its free end. These contacts form the output of the decoder. Decoder outputs are generally fed to small relays. These allow a high current load to be controlled, such as the model's propulsion motor. Using a relay also adds a damping time constant to the output, so that the intermittent contact with the reed contact (which is vibrating at the transmitter audible tone frequency) becomes a continuous output signal.
Each reed forms an indepe |
https://en.wikipedia.org/wiki/Rule%20of%20division%20%28combinatorics%29 | In combinatorics, the rule of division is a counting principle. It states that there are ways to do a task if it can be done using a procedure that can be carried out in ways, and for each way , exactly of the ways correspond to the way .
In a nutshell, the division rule is a common way to ignore "unimportant" differences when counting things.
Applied to Sets
In the terms of a set: "If the finite set is the union of n pairwise disjoint subsets each with elements, then ."
As a function
The rule of division formulated in terms of functions: "If is a function from to where and are finite sets, and that for every value there are exactly values such that (in which case, we say that is -to-one), then ."
Examples
Example 1
- How many different ways are there to seat four people around a circular table, where two seatings are considered the same when each person has the same left neighbor and the same right neighbor?
To solve this exercise we must first pick a random seat, and assign it to person 1, the rest of seats will be labeled in numerical order, in clockwise rotation around the table. There are 4 seats to choose from when we pick the first seat, 3 for the second, 2 for the third and just 1 option left for the last one. Thus there are 4! = 24 possible ways to seat them. However, since we only consider a different arrangement when they don't have the same neighbours left and right, only 1 out of every 4 seat choices matter.
Because there are 4 ways to choose for seat 1, by the division rule () there are different seating arrangements for 4 people around the table.
Example 2
- We have 6 coloured bricks in total, 4 of them are red and 2 are white, in how many ways can we arrange them?
If all bricks had different colours, the total of ways to arrange them would be , but since they don't have different colours, we would calculate it as following:
4 red bricks have arrangements
2 white bricks have arrangements
Total arrangements of 4 red and |
https://en.wikipedia.org/wiki/Network%20covalent%20bonding | A network solid or covalent network solid (also called atomic crystalline solids or giant covalent structures) is a chemical compound (or element) in which the atoms are bonded by covalent bonds in a continuous network extending throughout the material. In a network solid there are no individual molecules, and the entire crystal or amorphous solid may be considered a macromolecule. Formulas for network solids, like those for ionic compounds, are simple ratios of the component atoms represented by a formula unit.
Examples of network solids include diamond with a continuous network of carbon atoms and silicon dioxide or quartz with a continuous three-dimensional network of SiO2 units. Graphite and the mica group of silicate minerals structurally consist of continuous two-dimensional sheets covalently bonded within the layer, with other bond types holding the layers together. Disordered network solids are termed glasses. These are typically formed on rapid cooling of melts so that little time is left for atomic ordering to occur.
Properties
Hardness: Very hard, due to the strong covalent bonds throughout the lattice (deformation can be easier, however, in directions that do not require the breaking of any covalent bonds, as with flexing or sliding of sheets in graphite or mica).
Melting point: High, since melting means breaking covalent bonds (rather than merely overcoming weaker intermolecular forces).
Solid-phase electrical conductivity: Variable, depending on the nature of the bonding: network solids in which all electrons are used for sigma bonds (e.g. diamond, quartz) are poor conductors, as there are no delocalized electrons. However, network solids with delocalized pi bonds (e.g. graphite) or dopants can exhibit metal-like conductivity.
Liquid-phase electrical conductivity: Low, as the macromolecule consists of neutral atoms, meaning that melting does not free up any new charge carriers (as it would for an ionic compound).
Solubility: Generally insolu |
https://en.wikipedia.org/wiki/School%20of%20Life%20Sciences%20%28University%20of%20Dundee%29 | The School of Life Sciences at the University of Dundee conducts research into the molecular and cellular mechanisms underlying human health and disease.
History
Life Sciences research at the university began within the Department of Physiology. Following a campaign by Robert P. Cook who was a lecturer in Physiological Chemistry, the Department of Biochemistry was formed in 1965.... In 1970, the University of Dundee appointed Peter Garland CBE as its first Chair of Biochemistry based within the Department. Peter's arrival coincided with the opening of the Medical Sciences Institute (MSI) and Biological Sciences Institute (BSI) that provided up to date facilities for research to take place. The Department of Biochemistry moved from a converted stable block into the MSI alongside the Department of Anatomy and Physiology. In 1971, Peter recruited Sir Philip Cohen to Dundee, where he has remained ever since and who has played an instrumental role in the expansion of life sciences research in Dundee. The growth of the department was supported by Principal Adam Neville who redirected funds from other areas of the university. Peter had the ethos of employing the best is required to achieve the best, a strategy that exists to this day. Alongside his appointment of Philip, Peter also recruited David Lilley, Grahame Hardie and Chris Higgins. Further key appointments continued, this time led by Graham Warren; Peter's successor. In 1989, the Cancer Research Campaign supported the establishment of laboratories for David Glover, Birgitt Lane and David Lane. In 1990, the Medical Research Council set up the Protein Phosphorylation Unit which still exists today as the MRC Protein Phosphorylation and Ubiquitylation Unit (MRC PPU).
Expansion of research facilities
In 1994, the Wellcome Trust awarded £10 million to build the Wellcome Trust Biocentre which opened in 1997 and allowed further expansion in the research with several key appointments. As part of the fundraising efforts f |
https://en.wikipedia.org/wiki/Nikesh%20Arora | Nikesh Arora (born February 9, 1968) is an Indian-American business executive. Arora was formerly a senior executive at Google. He was the president of SoftBank Group from October 2014 to June 2016. On June 1, 2018, Arora took on the role of CEO and chairman at Palo Alto Networks.
Early life
Born to an Indian Air Force officer, Arora completed his schooling at The Air Force School (Subroto Park), and went on to graduate from the Indian Institute of Technology, BHU in Varanasi, India, with a bachelor of technology degree in electrical engineering in 1989. He holds a degree from Boston College and an MBA from Northeastern University. He has held the CFA designation since 1999.
Career
T-Motion PLC
In 2000, Arora established T-Motion, a subsidiary within Deutsche Telekom, "providing value-added services to the 3G Services of Deutsche Telekom." A few years after, in 2002, T-Motion was integrated into T-Mobile's core services.
Google
Arora joined Google in 2004. He held multiple senior operating leadership roles at Google, as vice president, Europe operations from 2004 to 2007, president Europe, Middle East and Africa from 2007 to 2009, and president, global sales operations and business development from 2009 to 2010. He was senior vice president and chief business officer of Google Inc. (Google) since January 2011 until July 2014.
He left Google in July 2014 resigning from the post of senior vice president and chief business officer.
SoftBank Corp.
As president and chief operating officer of SoftBank Corp. Arora received over $200 million in compensation over the last two years" while at the head of Softbank's operations. This pay package made him the world's highest paid executive.
Other experiences
Arora was chief marketing officer and a member of the management board at T-Mobile, Bharti Airtel, Europe and serves as a Trustee at the Paley Center for Media in Los Angeles, California.
Since 2007, Arora has been a senior advisor to Silver Lake Partners, a pri |
https://en.wikipedia.org/wiki/Spatial%20configuration | In landscape ecology, spatial configuration describes the spatial pattern of patches in a landscape. Most traditional spatial configuration measurements take into account aspects of patches within the landscape, including patches' size, shape, density, connectivity and fractal dimension. Other measurements are pixel-based, such as contagion and lacunarity. Together with spatial composition, spatial configuration is a basic component of landscape heterogeneity indices.
See also
Patch dynamics |
https://en.wikipedia.org/wiki/Normalizovan%C3%BD%20mo%C5%A1tomer | Normalizovaný moštoměr (°NM) is a scale used in the Czech Republic and Slovakia for measuring the sweetness of wine must. 1 °NM indicates 1 kg of sugar in 100 litres of must.
Czech wine and Slovak wine are classified by the level of sweetness of the must and other conditions such as the region where the grapes are grown. The scale is used for the determination of Quality Wine with Special Attributes. At the time of harvest, the sweetness of the grape must is measured and certified by the government controlling and testing institute. In the Czech Republic, this institute is the Czech State Agricultural & Food Inspectorate (SZPI).
Conversions to Other Scales:
°Oe = 3.845 x °NM + 10,8
°KMW = 0,732 x °NM +3,2 |
https://en.wikipedia.org/wiki/Schnirelmann%20density | In additive number theory, the Schnirelmann density of a sequence of numbers is a way to measure how "dense" the sequence is. It is named after Russian mathematician Lev Schnirelmann, who was the first to study it.
Definition
The Schnirelmann density of a set of natural numbers A is defined as
where A(n) denotes the number of elements of A not exceeding n and inf is infimum.
The Schnirelmann density is well-defined even if the limit of A(n)/n as fails to exist (see upper and lower asymptotic density).
Properties
By definition, and for all n, and therefore , and if and only if . Furthermore,
Sensitivity
The Schnirelmann density is sensitive to the first values of a set:
.
In particular,
and
Consequently, the Schnirelmann densities of the even numbers and the odd numbers, which one might expect to agree, are 0 and 1/2 respectively. Schnirelmann and Yuri Linnik exploited this sensitivity.
Schnirelmann's theorems
If we set , then Lagrange's four-square theorem can be restated as . (Here the symbol denotes the sumset of and .) It is clear that . In fact, we still have , and one might ask at what point the sumset attains Schnirelmann density 1 and how does it increase. It actually is the case that and one sees that sumsetting once again yields a more populous set, namely all of . Schnirelmann further succeeded in developing these ideas into the following theorems, aiming towards Additive Number Theory, and proving them to be a novel resource (if not greatly powerful) to attack important problems, such as Waring's problem and Goldbach's conjecture.
Theorem. Let and be subsets of . Then
Note that . Inductively, we have the following generalization.
Corollary. Let be a finite family of subsets of . Then
The theorem provides the first insights on how sumsets accumulate. It seems unfortunate that its conclusion stops short of showing being superadditive. Yet, Schnirelmann provided us with the following results, which sufficed for most of his purpose.
|
https://en.wikipedia.org/wiki/String%20interning | In computer science, string interning is a method of storing only one copy of each distinct string value, which must be immutable. Interning strings makes some string processing tasks more time- or space-efficient at the cost of requiring more time when the string is created or interned. The distinct values are stored in a string intern pool.
The single copy of each string is called its intern and is typically looked up by a method of the string class, for example String.intern() in Java. All compile-time constant strings in Java are automatically interned using this method.
String interning is supported by some modern object-oriented programming languages, including Java, Python, PHP (since 5.4), Lua
and .NET languages. Lisp, Scheme, Julia, Ruby and Smalltalk are among the languages with a symbol type that are basically interned strings. The library of the Standard ML of New Jersey contains an atom type that does the same thing. Objective-C's selectors, which are mainly used as method names, are interned strings.
Objects other than strings can be interned. For example, in Java, when primitive values are boxed into a wrapper object, certain values (any boolean, any byte, any char from 0 to 127, and any short or int between −128 and 127) are interned, and any two boxing conversions of one of these values are guaranteed to result in the same object.
History
Lisp introduced the notion of interned strings for its symbols. Historically, the data structure used as a string intern pool was called an oblist (when it was implemented as a linked list) or an obarray (when it was implemented as an array).
Modern Lisp dialects typically distinguish symbols from strings; interning a given string returns an existing symbol or creates a new one, whose name is that string. Symbols often have additional properties that strings do not (such as storage for associated values, or namespacing): the distinction is also useful to prevent accidentally comparing an interned string with |
https://en.wikipedia.org/wiki/Minimum%20total%20potential%20energy%20principle | The minimum total potential energy principle is a fundamental concept used in physics and engineering. It dictates that at low temperatures a structure or body shall deform or displace to a position that (locally) minimizes the total potential energy, with the lost potential energy being converted into kinetic energy (specifically heat).
Some examples
A free proton and free electron will tend to combine to form the lowest energy state (the ground state) of a hydrogen atom, the most stable configuration. This is because that state's energy is 13.6 electron volts (eV) lower than when the two particles separated by an infinite distance. The dissipation in this system takes the form of spontaneous emission of electromagnetic radiation, which increases the entropy of the surroundings.
A rolling ball will end up stationary at the bottom of a hill, the point of minimum potential energy. The reason is that as it rolls downward under the influence of gravity, friction produced by its motion transfers energy in the form of heat of the surroundings with an attendant increase in entropy.
A protein folds into the state of lowest potential energy. In this case, the dissipation takes the form of vibration of atoms within or adjacent to the protein.
Structural mechanics
The total potential energy, , is the sum of the elastic strain energy, , stored in the deformed body and the potential energy, , associated to the applied forces:
This energy is at a stationary position when an infinitesimal variation from such position involves no change in energy:
The principle of minimum total potential energy may be derived as a special case of the virtual work principle for elastic systems subject to conservative forces.
The equality between external and internal virtual work (due to virtual displacements) is:
where
= vector of displacements
= vector of distributed forces acting on the part of the surface
= vector of body forces
In the special case of elastic bodies, the right |
https://en.wikipedia.org/wiki/Development%20of%20Spore | Spore is a video game developed by Maxis and designed by Will Wright, released in September 2008. The game has drawn wide attention for its ability to simulate the development of a species on a galactic scope, using its innovation of user-guided evolution via the use of procedural generation for many of the components of the game, providing vast scope and open-ended gameplay.
Spore is a god game. The player molds and guides a species across many generations, growing it from a single-celled organism into a more complex animal. Eventually, the species becomes sentient. The player then begins molding and guiding this species' society, developing it into a space-faring civilization, at which point they can explore the galaxy in a space ship. Spores main innovation is the use of procedural generation for many of the components of the game, providing vast scope and open-endedness. Wright said, "I didn't want to make players feel like Luke Skywalker or Frodo Baggins. I wanted them to be like George Lucas or J. R. R. Tolkien." During the 2007 Technology Entertainment Design (TED) conference, Wright added that he wanted to create a "toy" for kids to inspire long-term thinking, stating, "I think toys can change the world."
History and development
Spore was originally a working title, suggested by Maxis developer Ocean Quigley, for the game which was first referred to by the general public as SimEverything. Even though SimEverything was a first choice name for Wright, the title Spore stuck. Wright adding it also freed him from the preconceptions another Sim title would have brought, saying "...Not putting 'Sim' in front of it was very refreshing to me. It feels like it wants to be breaking out into a completely different thing than what Sim was." Wright was inspired by the Drake equation and the 1977 film Powers of Ten when developing Spore.
Spore'''s development began in 2000, around the time that development began for The Sims Online. The earliest version was inspired by |
https://en.wikipedia.org/wiki/Stochastic%20discount%20factor | The concept of the stochastic discount factor (SDF) is used in financial economics and mathematical finance. The name derives from the price of an asset being computable by "discounting" the future cash flow by the stochastic factor , and then taking the expectation. This definition is of fundamental importance in asset pricing.
If there are n assets with initial prices at the beginning of a period and payoffs at the end of the period (all xs are random (stochastic) variables), then SDF is any random variable satisfying
The stochastic discount factor is sometimes referred to as the pricing kernel as, if the expectation is written as an integral, then can be interpreted as the kernel function in an integral transform. Other names sometimes used for the SDF are the "marginal rate of substitution" (the ratio of utility of states, when utility is separable and additive, though discounted by the risk-neutral rate), a "change of measure", "state-price deflator" or a "state-price density".
Properties
The existence of an SDF is equivalent to the law of one price; similarly, the existence of a strictly positive SDF is equivalent to the absence of arbitrage opportunities (see Fundamental theorem of asset pricing). This being the case, then if is positive, by using to denote the return, we can rewrite the definition as
and this implies
Also, if there is a portfolio made up of the assets, then the SDF satisfies
By a simple standard identity on covariances, we have
Suppose there is a risk-free asset. Then implies . Substituting this into the last expression and rearranging gives the following formula for the risk premium of any asset or portfolio with return :
This shows that risk premiums are determined by covariances with any SDF.
See also
Hansen–Jagannathan bound |
https://en.wikipedia.org/wiki/3D%20XPoint | 3D XPoint (pronounced three-D cross point) is a discontinued non-volatile memory (NVM) technology developed jointly by Intel and Micron Technology. It was announced in July 2015 and was available on the open market under the brand name Optane (Intel) from April 2017 to July 2022. Bit storage is based on a change of bulk resistance, in conjunction with a stackable cross-grid data access array. Initial prices are less than dynamic random-access memory (DRAM) but more than flash memory.
As a non-volatile memory, 3D XPoint has a number of features that distinguish it from other currently available RAM and NVRAM. Although the first generations of 3D XPoint were not especially large or fast, 3D XPoint was used to create some of the fastest SSDs available as of 2019, with small-write latency. As the memory is inherently fast, and byte-addressable, techniques such as read-modify-write and caching used to enhance traditional SSDs are not needed to obtain high performance. In addition, chipsets such as Cascade Lake are designed with inbuilt support for 3D XPoint, that allow it to be used as a caching or acceleration disk, and it is also fast enough to be used as non-volatile RAM (NVRAM) in a DIMM package.
History
Development
Development of 3D XPoint began around 2012. Intel and Micron had developed other non-volatile phase-change memory (PCM) technologies previously; Mark Durcan of Micron said 3D XPoint architecture differs from previous offerings of PCM, and uses chalcogenide materials for both selector and storage parts of the memory cell that are faster and more stable than traditional PCM materials like GST. But today, it is thought of as a subset of ReRAM.
3D XPoint has been stated to use electrical resistance and to be bit addressable. Similarities to the resistive random-access memory under development by Crossbar Inc. have been noted, but 3D XPoint uses different storage physics. Specifically, transistors are replaced by threshold switches as selectors in the memo |
https://en.wikipedia.org/wiki/Shulba%20Sutras | The Shulva Sutras or Śulbasūtras (Sanskrit: शुल्बसूत्र; : "string, cord, rope") are sutra texts belonging to the Śrauta ritual and containing geometry related to fire-altar construction.
Purpose and origins
The Shulba Sutras are part of the larger corpus of texts called the Shrauta Sutras, considered to be appendices to the Vedas. They are the only sources of knowledge of Indian mathematics from the Vedic period. Unique fire-altar shapes were associated with unique gifts from the Gods. For instance, "he who desires heaven is to construct a fire-altar in the form of a falcon"; "a fire-altar in the form of a tortoise is to be constructed by one desiring to win the world of Brahman" and "those who wish to destroy existing and future enemies should construct a fire-altar in the form of a rhombus".
The four major Shulba Sutras, which are mathematically the most significant, are those attributed to Baudhayana, Manava, Apastamba and Katyayana. Their language is late Vedic Sanskrit, pointing to a composition roughly during the 1st millennium BCE. The oldest is the sutra attributed to Baudhayana, possibly compiled around 800 BCE to 500 BCE. Pingree says that the Apastamba is likely the next oldest; he places the Katyayana and the Manava third and fourth chronologically, on the basis of apparent borrowings. According to Plofker, the Katyayana was composed after "the great grammatical codification of Sanskrit by Pāṇini in probably the mid-fourth century BCE", but she places the Manava in the same period as the Baudhayana.
With regard to the composition of Vedic texts, Plofker writes,The Vedic veneration of Sanskrit as a sacred speech, whose divinely revealed texts were meant to be recited, heard, and memorized rather than transmitted in writing, helped shape Sanskrit literature in general. ... Thus texts were composed in formats that could be easily memorized: either condensed prose aphorisms (sūtras, a word later applied to mean a rule or algorithm in general) or ver |
https://en.wikipedia.org/wiki/The%20Extended%20Phenotype | The Extended Phenotype is a 1982 book by the evolutionary biologist Richard Dawkins, in which the author introduced a biological concept of the same name. The book’s main idea is that phenotype should not be limited to biological processes such as protein biosynthesis or tissue growth, but extended to include all effects that a gene has on its environment, inside or outside the body of the individual organism.
Dawkins considers The Extended Phenotype to be a sequel to The Selfish Gene (1976) aimed at professional biologists, and as his principal contribution to evolutionary theory.
Summary
Genes as the unit of selection in evolution
The central thesis of The Extended Phenotype, and of its predecessor by the same author, The Selfish Gene, is that individual organisms are not the true units of natural selection. Instead, the gene — or the ‘active, germ-line replicator’ — is the unit upon which the forces of evolutionary selection and adaptation act. It is genes that succeed or fail in evolution, meaning that they either succeed or fail in replicating themselves across multiple generations.
These replicators are not subject to natural selection directly, but indirectly through their “phenotypical effects.” These effects are all the effects that the gene (or replicator) has on the world at large, not just in the body of the organism in which it is contained. In taking as its starting point the gene as the unit of selection, The Extended Phenotype is a direct extension of Dawkins’ first book, The Selfish Gene.
Genes synthesise only proteins
Dawkins argues that the only thing that genes control directly is the synthesis of proteins. He points to the arbitrariness of restricting the idea of the phenotype to apply only to the phenotypic expression of an organism's genes in its own body. Dawkins develops this idea by pointing to the effect that a gene may have on an organism's environment through that organism's behaviour.
Genes may affect more than the organism's |
https://en.wikipedia.org/wiki/VODnet | A VODnet is a Video On Demand-driven cable and satellite television network. It is a non-linear television network in that the content resides on a server and the consumer calls up the particular program they want to watch from a digital menu. This is in contrast to a linear network that shows scheduled programs throughout the day. Usually VODnets are genre portal based. For example, Sportskool and The Ski Channel would be found under "Sports" and MGM Channel would be under "Movies."
Currently, all major cable, satellite and telco distributors and most mid-size cable operators carry VODnets.
The majority of VODnets launched in 2007 and 2008.
VODnets include:
FEARnet
MGM Channel
ExerciseTV
The Ski Channel
Lifeskool formerly Mag Rack
Wheels TV
Karaoke Channel
Havoc TV
Music Choice
Studio 4 Fitness
Concert TV
EuroCinema
Film Festival
Anime Network
Players Network
Criteria
Traditional Cable Networks that have VOD Video On Demand are not considered a VODnet because VOD is not the main distribution method for the channel. For example, Speed Channel which has VOD programming available through most cable and satellite providers, would not be considered a VODnet because their main distribution method is linear.
Important Facts
In March 2008, ExerciseTV reached its 100 millionth view. In October, 2008, Mag Rack was split into two companies, Lifeskool and Sportskool, and sold by Rainbow Media, a subsidiary of Cablevision to new owners. Shortly thereafter Lifeskool additionally purchased Concert TV and began using the name Mag Rack again.
In early 2009 Ripe Digital Entertainment went bankrupt. They had supposedly raised over $50 million, but spent lavishly and were the victim of poor timing. ExerciseTV ceased distribution in November, 2011, and was replaced on Time Warner Cable by Sportskool Fit, a new channel created by Sportskool.
External links
, Music Choice official site
, The Ski Channel official site
, Lifeskool official site |
https://en.wikipedia.org/wiki/Logical%20effort | The method of logical effort, a term coined by Ivan Sutherland and Bob Sproull in 1991, is a straightforward technique used to estimate delay in a CMOS circuit. Used properly, it can aid in selection of gates for a given function (including the number of stages necessary) and sizing gates to achieve the minimum delay possible for a circuit.
Derivation of delay in a logic gate
Delay is expressed in terms of a basic delay unit, τ = 3RC, the delay of an inverter driving an identical inverter without any additional capacitance added by interconnects or other loads; the unitless number associated with this is known as the normalized delay.
(Some authors prefer define the basic delay unit as the fanout of 4 delay—the delay of one inverter driving 4 identical inverters).
The absolute delay is then simply defined as the product of the normalized delay of the gate, d, and τ:
In a typical 600-nm process τ is about 50 ps. For a 250-nm process, τ is about 20 ps. In modern 45 nm processes the delay is approximately 4 to 5 ps.
The normalized delay in a logic gate can be expressed as a summation of two primary terms: normalized parasitic delay, p (which is an intrinsic delay of the gate and can be found by considering the gate driving no load), and stage effort, f (which is dependent on the load as described below). Consequently,
The stage effort is divided into two components: a logical effort, g, which is the ratio of the input capacitance of a given gate to that of an inverter capable of delivering the same output current (and hence is a constant for a particular class of gate and can be described as capturing the intrinsic properties of the gate), and an electrical effort, h, which is the ratio of the input capacitance of the load to that of the gate. Note that "logical effort" does not take the load into account and hence we have the term "electrical effort" which takes the load into account. The stage effort is then simply:
Combining these equations yields a basic equa |
https://en.wikipedia.org/wiki/Phalaenopsis%20%C3%97%20veitchiana | Phalaenopsis × veitchiana is a species of orchid endemic to the Philippines. It is a hybrid of Phalaenopsis equestris and Phalaenopsis schilleriana. It occurs naturally and has also been artificially re-created. It is named after the British horticulturalist Harry J. Veitch. |
https://en.wikipedia.org/wiki/Bat1K | Bat1K is a project to sequence the genomes of all living bat species to the level of chromosomes and then make the data publicly available. The project began in 2017.
History
Bat1K was founded in 2017. Zoologist and geneticist Emma Teeling and neurogeneticist Sonja Vernes are co-founders. The Bat1K consortium includes researchers from institutions such as University College Dublin, University of Bristol, Max Planck Institute of Molecular Cell Biology and Genetics, and Max Planck Institute for Psycholinguistics. Notable members include Eugene Myers, Liliana M. Dávalos, Nancy Simmons, and Erich Jarvis. As of November 2017, there were 148 members in total, consisting of bat biologists, genome technologists, conservationists, and computational scientists.
Applications
Several research areas could be furthered by documenting bat genomes. These include healthy ageing, disease resistance, ecosystem function and ecosystem services, sensory perception, communication, limb development, and mammal genome structure.
Results
In 2020, the genomes of six species were published: the greater horseshoe bat, Egyptian fruit bat, pale spear-nosed bat, greater mouse-eared bat, Kuhl's pipistrelle, and the velvety free-tailed bat. These genomes were called "comparable to the best reference-quality genomes that have so far been generated for any eukaryote with a gigabase-sized genome". In 2020, the project's stated goal was to sequence an additional 27 genomes, with a representative from each family of bats, within the next year.
See also
Genome project |
https://en.wikipedia.org/wiki/Cassini%27s%20laws | Cassini's laws provide a compact description of the motion of the Moon. They were established in 1693 by Giovanni Domenico Cassini, a prominent scientist of his time.
Refinements of these laws to include physical librations have been made, and they have been generalized to treat other satellites and planets.
Cassini's laws
The Moon has a 1:1 spin–orbit resonance. This means that the rotation–orbit ratio of the Moon is such that the same side of it always faces the Earth.
The Moon's rotational axis maintains a constant angle of inclination from the ecliptic plane. The Moon's rotational axis precesses so as to trace out a cone that intersects the ecliptic plane as a circle.
A plane formed from a normal to the ecliptic plane and a normal to the Moon's orbital plane will contain the Moon's rotational axis.
In the case of the Moon, its rotational axis always points some 1.5 degrees away from the North ecliptic pole. The normal to the Moon's orbital plane and its rotational axis are always on opposite sides of the normal to the ecliptic.
Therefore, both the normal to the orbital plane and the Moon's rotational axis precess around the ecliptic pole with the same period. The period is about 18.6 years and the motion is retrograde.
Cassini state
A system obeying these laws is said to be in a Cassini state, that is: an evolved rotational state where the spin axis, orbit normal, and normal to the Laplace plane are coplanar while the obliquity remains constant. The Laplace plane is defined as the plane about which a planet or satellite orbit precesses with constant inclination. The normal to the Laplace plane for a moon is between the planet's spin axis and the planet's orbit normal, being closer to the latter if the moon is distant from the planet. If a planet itself is in a Cassini state, the Laplace plane is the invariable plane of the stellar system.
Cassini state 1 is defined as the situation in which both the spin axis and the orbit normal axis are on the same |
https://en.wikipedia.org/wiki/Cyber%20resilience | Cyber resilience refers to an entity's ability to continuously deliver the intended outcome, despite cyber attacks. Resilience to cyber attacks is essential to IT systems, critical infrastructure, business processes, organizations, societies, and nation-states.
Adverse cyber events are those that negatively impact the availability, integrity, or confidentiality of networked IT systems and associated information and services. These events may be intentional (e.g. cyber attack) or unintentional (e.g. failed software update) and caused by humans, nature, or a combination thereof.
Unlike cyber security, which is designed to protect systems, networks and data from cyber crimes, cyber resilience is designed to prevent systems and networks from being derailed in the event that security is compromised. Cyber security is effective without compromising the usability of systems and there is a robust continuity business plan to resume operations, if the cyber attack is successful.
Cyber resilience helps businesses to recognize that hackers have the advantage of innovative tools, element of surprise, target and can be successful in their attempt. This concept helps business to prepare, prevent, respond and successfully recover to the intended secure state. This is a cultural shift as the organization sees security as a full-time job and embedded security best practices in day-to-day operations. In comparison to cyber security, cyber resilience requires the business to think differently and be more agile on handling attacks.
The objective of cyber resilience is to maintain the entity's ability to deliver the intended outcome continuously at all times. This means doing so even when regular delivery mechanisms have failed, such as during a crisis or after a security breach. The concept also includes the ability to restore or recover regular delivery mechanisms after such events, as well as the ability to continuously change or modify these delivery mechanisms, if needed in the |
https://en.wikipedia.org/wiki/Robert%20Morris%20%28mathematician%29 | Robert (Rob) Morris is a mathematician who works in combinatorics, probability, graph theory and Ramsey theory. He is a researcher at IMPA.
In 2015, Morris was awarded the European Prize in Combinatorics for "his profound results in extremal and probabilistic combinatorics particularly for his result on independent sets in hypergraphs which found immediately several applications in additive number theory and combinatorics, such as the solution of old problem of Erdős and for establishing tight bounds for Ramsey numbers, and also on random cellular automata and bootstrap problems in percolation."
In 2016, he was one of the winners of the George Pólya Prize.
He graduated with a Ph.D. from The University of Memphis in 2006 under the supervision of Béla Bollobás.
He was awarded the 2018 Fulkerson Prize. Also in 2018, he was an invited speaker at the International Congress of Mathematicians in Rio de Janeiro. |
https://en.wikipedia.org/wiki/Camera%20Serial%20Interface | The Camera Serial Interface (CSI) is a specification of the Mobile Industry Processor Interface (MIPI) Alliance. It defines an interface between a camera and a host processor. The latest active interface specifications are CSI-2 v3.0, CSI-3 v1.1 and CCS v1.0 which were released in 2019, 2014 and 2017 respectively.
Standards
CSI-1
CSI-1 was the original standard MIPI interface for cameras. It emerged as an architecture to define the interface between a camera and a host processor. Its successors were MIPI CSI-2 and MIPI CSI-3, two standards that are still evolving.
CSI-2
The MIPI CSI-2 v1.0 specification was released in 2005. It uses either D-PHY or C-PHY (Both standards are set by the MIPI Alliance) as a physical layer option. The protocol is divided into the following layers:
Physical Layer (C-PHY/D-PHY)
Lane Merger Layer.
Low Level Protocol Layer.
Pixel to Byte Conversion Layer
Application Layer
In April 2017, the CSI-2 v2.0 specification was released. CSI-2 v2.0 brought support for RAW-16 and RAW-20 color depth, increase virtual channels from 4 to 32, Latency Reduction and Transport Efficiency (LRTE), Differential Pulse-Code Modulation (DPCM) compression and scrambling to reduce Power Spectral Density.
In September 2019, the CSI-2 v3.0 specification was released. CSI-2 v3.0 introduced Unified Serial Link (USL), Smart Region of Interest (SROI), End-of-Transmission Short Packet (EoTp) and support for RAW-24 color depth.
CSI-3
MIPI CSI-3 is a high-speed, bidirectional protocol primarily intended for image and video transmission between cameras and hosts within a multi-layered, peer-to-peer, UniPro-based M-PHY device network. It was originally released in 2012 and got re-released in version 1.1 in 2014.
Camera Command Set (CCS)
The Camera Command Set (CCS) v1.0 specification was released on November 30, 2017. CCS defines a standard set of functionalities for controlling image sensors using CSI-2.
Technology & speeds
For EMI reasons the system design |
https://en.wikipedia.org/wiki/Permanent%20signal | Permanent signal (PS) in American telephony terminology, or permanent loop in British usage, is a condition in which a POTS line is off-hook without connection for an extended period of time. This is indicated in modern switches by the silent termination after the off-hook tone times out and the telephone exchange computer puts the telephone line on its High & Wet list or Wetlist. In older switches, however, a Permanent Signal Holding Trunk (PSHT) would play either an off-hook tone (howler tone) or a 480/500 Hz high tone (which would subsequently bleed into adjacent lines via crosstalk). Off-hook tone is a tone of increasing intensity that is intended to alert telephone users to the fact that the receiver has been left off the hook without being connected in a call. On some systems before the off-hook tone is played, an intercept message may be announced. The most common message reads as follows; "If you'd like to make a call, please hang up and try again. If you need help, hang up and then dial your operator."
Permanent signal can also describe the state of a trunk that is seized but has not been dialed upon, if it remains in a busy condition (sometimes alerting with reorder).
In most mid-20th-century switching equipment, a permanent signal would tie up a junctor circuit, diminishing the ability of the switch to handle outgoing calls. When flooded cables or other conditions made this a real problem, switch staff would open the cable, or paper the off-normal contacts of the crossbar switch, or block the line relay from operating. These methods had the disadvantage of blocking all outgoing calls from that line until it was manually cleared. Manufacturers also sold devices that monitored the talk wires and held up the cutoff relay or crossbar hold magnet until the condition cleared. Some crossbar line circuit designs had a park condition allowing the line circuit itself to monitor the line.
Stored program control exchanges finally solved the problem, by sett |
https://en.wikipedia.org/wiki/Multiple%20line%20segment%20intersection | In computational geometry, the multiple line segment intersection problem supplies a list of line segments in the Euclidean plane and asks whether any two of them intersect (cross).
Simple algorithms examine each pair of segments. However, if a large number of possibly intersecting segments are to be checked, this becomes increasingly inefficient since most pairs of segments are not close to one another in a typical input sequence. The most common, and more efficient, way to solve this problem for a high number of segments is to use a sweep line algorithm, where we imagine a line sliding across the line segments and we track which line segments it intersects at each point in time using a dynamic data structure based on binary search trees. The Shamos–Hoey algorithm applies this principle to solve the line segment intersection detection problem, as stated above, of determining whether or not a set of line segments has an intersection; the Bentley–Ottmann algorithm works by the same principle to list all intersections in logarithmic time per intersection.
See also
Bentley–Ottmann algorithm |
https://en.wikipedia.org/wiki/Colobot | Colobot (Colonize with Bots) is an educational, post apocalyptic real-time strategy video game featuring 3D graphics, created by Swiss developer Epsitec SA. The objective of the game is to find a planet for colonization by the human race by establishing a basic infrastructure on the surface and eliminating any alien life forms endangering the expedition. The game takes place on the Earth, Moon, and seven fictional planets. The main feature of the game, which makes it educational, is the possibility for players to program their robots using a programming language similar to C++ or Java.
Plot overview
Life on earth is threatened by a devastating cataclysm, forcing mankind to move out and search for a new home. A first expedition composed solely of robots was sent to find another habitable planet. However, for unknown reasons, the mission was a disaster and never returned.
With only a few robots for companions, the player must travel to new planets. Houston, Earth Mission Control as well as a spy satellite will transmit valuable information to the player. The player needs to build the infrastructure necessary to gather raw materials, energy supplies, and produce the weapons necessary to defend themselves. By programming robots, the player can delegate tasks to them, allowing the player to continue their mission while their robots upkeep the base, fight off enemies, harvest materials, and perform any other tasks assigned to them.
Missions
In the game, the player explores Earth, Moon and seven fictional planets.
Language overview
The programming language used in is CBOT, syntactically similar to C++ and Java. Example code for a bot to find a piece of titanium ore and deliver it to a purification facility:
extern void object::FetchTitanium()
{
object item; // declare variable
item = radar(TitaniumOre); // find a piece of titanium ore
goto(item.position); // go to the ore
grab(); // pick up whatever is in front of the robot (presumably the ore)
item = |
https://en.wikipedia.org/wiki/Passphrase | A passphrase is a sequence of words or other text used to control access to a computer system, program or data. It is similar to a password in usage, but a passphrase is generally longer for added security. Passphrases are often used to control both access to, and the operation of, cryptographic programs and systems, especially those that derive an encryption key from a passphrase. The origin of the term is by analogy with password. The modern concept of passphrases is believed to have been invented by Sigmund N. Porter in 1982.
Security
Considering that the entropy of written English is less than 1.1 bits per character, passphrases can be relatively weak. NIST has estimated that the 23-character passphrase "IamtheCapitanofthePina4" contains a 45-bit strength. The equation employed here is:
4 bits (1st character) + 14 bits (characters 2–8) + 18 bits (characters 9–20) + 3 bits (characters 21–23) + 6 bits (bonus for upper case, lower case, and alphanumeric) = 45 bits
(This calculation does not take into account that this is a well-known quote from the operetta H.M.S. Pinafore. An MD5 hash of this passphrase can be cracked in 4 seconds using crackstation.net, indicating that the phrase is found in password cracking databases.)
Using this guideline, to achieve the 80-bit strength recommended for high security (non-military) by NIST, a passphrase would need to be 58 characters long, assuming a composition that includes uppercase and alphanumeric.
There is room for debate regarding the applicability of this equation, depending on the number of bits of entropy assigned. For example, the characters in five-letter words each contain 2.3 bits of entropy, which would mean only a 35-character passphrase is necessary to achieve 80 bit strength.
If the words or components of a passphrase may be found in a language dictionary—especially one available as electronic input to a software program—the passphrase is rendered more vulnerable to dictionary attack. This is a particul |
https://en.wikipedia.org/wiki/Mir-580%20microRNA%20precursor%20family | In molecular biology mir-580 microRNA is a short RNA molecule. MicroRNAs function to regulate the expression levels of other genes by several mechanisms.
See also
MicroRNA |
https://en.wikipedia.org/wiki/Bulk%20temperature | In thermofluids dynamics, the bulk temperature, or the average bulk temperature in the thermal fluid, is a convenient reference point for evaluating properties related to convective heat transfer, particularly in applications related to flow in pipes and ducts.
The concept of the bulk temperature is that adiabatic mixing of the fluid from a given cross section of the duct will result in some equilibrium temperature that accurately reflects the average temperature of the moving fluid, more so than a simple average like the film temperature. |
https://en.wikipedia.org/wiki/Homogeneity%20%28physics%29 | In physics, a homogeneous material or system has the same properties at every point; it is uniform without irregularities. A uniform electric field (which has the same strength and the same direction at each point) would be compatible with homogeneity (all points experience the same physics). A material constructed with different constituents can be described as effectively homogeneous in the electromagnetic materials domain, when interacting with a directed radiation field (light, microwave frequencies, etc.).
Mathematically, homogeneity has the connotation of invariance, as all components of the equation have the same degree of value whether or not each of these components are scaled to different values, for example, by multiplication or addition. Cumulative distribution fits this description. "The state of having identical cumulative distribution function or values".
Context
The definition of homogeneous strongly depends on the context used. For example, a composite material is made up of different individual materials, known as "constituents" of the material, but may be defined as a homogeneous material when assigned a function. For example, asphalt paves our roads, but is a composite material consisting of asphalt binder and mineral aggregate, and then laid down in layers and compacted. However, homogeneity of materials does not necessarily mean isotropy. In the previous example, a composite material may not be isotropic.
In another context, a material is not homogeneous in so far as it is composed of atoms and molecules. However, at the normal level of our everyday world, a pane of glass, or a sheet of metal is described as glass, or stainless steel. In other words, these are each described as a homogeneous material.
A few other instances of context are: dimensional homogeneity (see below) is the quality of an equation having quantities of same units on both sides; homogeneity (in space) implies conservation of momentum; and homogeneity in time implies co |
https://en.wikipedia.org/wiki/Advanced%20planning%20and%20scheduling | Advanced planning and scheduling (APS, also known as advanced manufacturing) refers to a manufacturing management process by which raw materials and production capacity are optimally allocated to meet demand. APS is especially well-suited to environments where simpler planning methods cannot adequately address complex trade-offs between competing priorities. Production scheduling is intrinsically very difficult due to the (approximately) factorial dependence of the size of the solution space on the number of items/products to be manufactured.
Difficulty of production planning
Traditional production planning and scheduling systems (such as manufacturing resource planning) use a stepwise procedure to allocate material and production capacity. This approach is simple but cumbersome, and does not readily adapt to changes in demand, resource capacity or material availability. Materials and capacity are planned separately, and many systems do not consider material or capacity constraints, leading to infeasible plans. However, attempts to change to the new system have not always been successful, which has called for the combination of management philosophy with manufacturing.
Unlike previous systems, APS simultaneously plans and schedules production based on available materials, labor and plant capacity.
APS has commonly been applied where one or more of the following conditions are present:
make to order (as distinct from make to stock) manufacturing
capital-intensive production processes, where plant capacity is constrained
products 'competing' for plant capacity: where many different products are produced in each facility
products that require a large number of components or manufacturing tasks
production necessitates frequent schedule changes which cannot be predicted before the event
Advanced planning & scheduling software enables manufacturing scheduling and advanced scheduling optimization within these environments.
Further reading |
https://en.wikipedia.org/wiki/Tolman%20length | The Tolman length (also known as Tolman's delta) measures the extent by which the surface tension of a small liquid drop deviates from its planar value. It is conveniently defined in terms of an expansion in , with the equimolar radius (defined below) of the liquid drop, of the pressure difference across the droplet's surface:
(1)
In this expression, is the pressure difference between the (bulk) pressure of the liquid inside and the pressure of the vapour outside, and is the surface tension of the planar interface, i.e. the interface with zero curvature . The Tolman length is thus defined as the leading order correction in an expansion in .
The equimolar radius is defined so that the superficial density is zero, i.e., it is defined by imagining a sharp mathematical dividing surface with a uniform internal and external density, but where the total mass of the pure fluid is exactly equal to the real situation. At the atomic scale in a real drop, the surface is not sharp, rather the density gradually drops to zero, and the Tolman length captures the fact that the idealized equimolar surface does not necessarily coincide with the idealized tension surface.
Another way to define the Tolman length is to consider the radius dependence of the surface tension, . To leading order in one has:
(2)
Here denotes the surface tension (or (excess) surface free energy) of a liquid drop with radius , whereas denotes its value in the planar limit.
In both definitions (1) and (2) the Tolman length is defined as a coefficient in an expansion in and therefore does not depend on .
Furthermore, the Tolman length can be related to the radius of spontaneous curvature when one compares the free energy method of Helfrich with the method of Tolman:
Any result for the Tolman length therefore gives information about the radius of spontaneous curvature, . If the Tolman length is known to be positive (with ) the interface tends to curve towards the liquid ph |
https://en.wikipedia.org/wiki/VCR/Blu-ray%20combo | A VCR/Blu-ray combo is a multiplex or converged device, convenient for consumers who wish to use both VHS tapes and the newer high-definition Blu-ray Disc technology.
When Blu-ray Disc players went on the market in mid-2006, the final major Hollywood motion picture on VHS (David Cronenberg's A History of Violence) had already been released. Nonetheless, some homes still had a large supply of VHS tapes due to its nearly-30 year history as a consumer device. New-old stock of blank VHS tapes are still available for purchase at some stores, and tapes still appear to be manufactured as of December 2022.
Very few VCR/Blu-ray combos were produced, some of which played additional formats including DVD, VCD, CD, SD card (and with it, MMC cards, since SD sockets are compatible with MMC cards), and/or USB media. Some models were also able to play BD Live media if connected to the Internet. Most of these formats are carried over from standalone Blu-ray Disc players, as most Blu-ray Disc players are designed to play DVDs and CDs in addition to Blu-ray Discs, and many Blu-ray Disc players come equipped with BD Live capabilities and/or SD card slot to have a still picture slideshow or show personal home movies.
These devices were among the only VCRs (alongside some later model VCR/DVD combos) to be equipped with an HDMI port for HDTV viewing upscaling to several different types of resolutions including 1080p, 1080i, and 720p.
See also
Combo television unit
VCR/DVD combo |
https://en.wikipedia.org/wiki/Scherk%20surface | In mathematics, a Scherk surface (named after Heinrich Scherk) is an example of a minimal surface. Scherk described two complete embedded minimal surfaces in 1834; his first surface is a doubly periodic surface, his second surface is singly periodic. They were the third non-trivial examples of minimal surfaces (the first two were the catenoid and helicoid). The two surfaces are conjugates of each other.
Scherk surfaces arise in the study of certain limiting minimal surface problems and in the study of harmonic diffeomorphisms of hyperbolic space.
Scherk's first surface
Scherk's first surface is asymptotic to two infinite families of parallel planes, orthogonal to each other, that meet near z = 0 in a checkerboard pattern of bridging arches. It contains an infinite number of straight vertical lines.
Construction of a simple Scherk surface
Consider the following minimal surface problem on a square in the Euclidean plane: for a natural number n, find a minimal surface Σn as the graph of some function
such that
That is, un satisfies the minimal surface equation
and
What, if anything, is the limiting surface as n tends to infinity? The answer was given by H. Scherk in 1834: the limiting surface Σ is the graph of
That is, the Scherk surface over the square is
More general Scherk surfaces
One can consider similar minimal surface problems on other quadrilaterals in the Euclidean plane. One can also consider the same problem on quadrilaterals in the hyperbolic plane. In 2006, Harold Rosenberg and Pascal Collin used hyperbolic Scherk surfaces to construct a harmonic diffeomorphism from the complex plane onto the hyperbolic plane (the unit disc with the hyperbolic metric), thereby disproving the Schoen–Yau conjecture.
Scherk's second surface
Scherk's second surface looks globally like two orthogonal planes whose intersection consists of a sequence of tunnels in alternating directions. Its intersections with horizontal planes consists of alternating hyperbolas.
I |
https://en.wikipedia.org/wiki/Conjugate%20eye%20movement | Conjugate eye movement refers to motor coordination of the eyes that allows for bilateral fixation on a single object.
A conjugate eye movement is a movement of both eyes in the same direction to maintain binocular gaze (also referred to as “yoked” eye movement). This is in contrast to vergence eye movement, where binocular gaze is maintained by moving eyes in opposite directions, such as going “cross eyed” to view an object moving towards the face. Conjugate eye movements can be in any direction, and can accompany both saccadic eye movements and smooth pursuit eye movements.
Conjugate eye movements are used to change the direction of gaze without changing the depth of gaze. This can be used to either follow a moving object, or change focus entirely. When following a moving object, conjugate eye movements allow individuals to stabilize their perception of the moving object, and focus on the object rather than the rest of the visual world. When changing focus, conjugate eye movements allow for the perception of a stabilized world relative to an individual, rather than the perception of the world “jumping” as the individual’s gaze shifts. Without conjugate eye movements, there would be no synchronicity of the information obtained by each eye, so an individual would not be able to willingly move their eyes around a scene while still maintaining depth perception and scene or object stability.
Several centers in the brainstem are involved. Horizontal conjugate gaze is controlled by the nuclei of the Ocular Nerve, CN III, and the Abducens nerve, CN VI, the paramedian pontine reticular formation, and the nucleus prepositus hypoglossi-medial vestibular nucleus. Vertical conjugate gaze is controlled by the nuclei of CN III and the Trochlear nerve, CN IV, the rostral interstitial nucleus of medial longitudinal fasciculus (riMLF), and the interstitial nucleus of Cajal.
Disorders of conjugate gaze typically consist of the inability to move one or both eyes in the desired |
https://en.wikipedia.org/wiki/Glossary%20of%20category%20theory | This is a glossary of properties and concepts in category theory in mathematics. (see also Outline of category theory.)
Notes on foundations: In many expositions (e.g., Vistoli), the set-theoretic issues are ignored; this means, for instance, that one does not distinguish between small and large categories and that one can arbitrarily form a localization of a category. Like those expositions, this glossary also generally ignores the set-theoretic issues, except when they are relevant (e.g., the discussion on accessibility.)
Especially for higher categories, the concepts from algebraic topology are also used in the category theory. For that see also glossary of algebraic topology.
The notations and the conventions used throughout the article are:
[n] = {0, 1, 2, …, n}, which is viewed as a category (by writing .)
Cat, the category of (small) categories, where the objects are categories (which are small with respect to some universe) and the morphisms functors.
Fct(C, D), the functor category: the category of functors from a category C to a category D.
Set, the category of (small) sets.
sSet, the category of simplicial sets.
"weak" instead of "strict" is given the default status; e.g., "n-category" means "weak n-category", not the strict one, by default.
By an ∞-category, we mean a quasi-category, the most popular model, unless other models are being discussed.
The number zero 0 is a natural number.
A
B
C
D
E
F
G
H
I
K
L
M
N
O
P
Q
R
S
T
U
W
Y
Z
Notes |
https://en.wikipedia.org/wiki/List%20of%20Cameroonian%20flags | The following is a list of flags of Cameroon. For more information, see flag of Cameroon.
National flag and state flag
Flags of political parties
Separatist movements flags
Historical flags
See also
Flag of Cameroon
Coat of arms of Cameroon |
https://en.wikipedia.org/wiki/Hgh1%20homolog | HGH1 homolog is a protein that in humans is encoded by the HGH1 gene. |
https://en.wikipedia.org/wiki/Paul%20Erd%C5%91s | Paul Erdős ( ; 26 March 1913 – 20 September 1996) was a Hungarian mathematician. He was one of the most prolific mathematicians and producers of mathematical conjectures of the 20th century. pursued and proposed problems in discrete mathematics, graph theory, number theory, mathematical analysis, approximation theory, set theory, and probability theory. Much of his work centered around discrete mathematics, cracking many previously unsolved problems in the field. He championed and contributed to Ramsey theory, which studies the conditions in which order necessarily appears. Overall, his work leaned towards solving previously open problems, rather than developing or exploring new areas of mathematics.
Erdős published around 1,500 mathematical papers during his lifetime, a figure that remains unsurpassed. He firmly believed mathematics to be a social activity, living an itinerant lifestyle with the sole purpose of writing mathematical papers with other mathematicians. He was known both for his social practice of mathematics, working with more than 500 collaborators, and for his eccentric lifestyle; Time magazine called him "The Oddball's Oddball". He devoted his waking hours to mathematics, even into his later years—indeed, his death came at a mathematics conference in Warsaw. Erdős's prolific output with co-authors prompted the creation of the Erdős number, the number of steps in the shortest path between a mathematician and Erdős in terms of co-authorships.
Life
Paul Erdős was born on 26 March 1913, in Budapest, Austria-Hungary, the only surviving child of Anna (née Wilhelm) and Lajos Erdős (né Engländer). His two sisters, aged three and five, both died of scarlet fever a few days before he was born. His parents, both Jewish, were high school mathematics teachers. His fascination with mathematics developed early—he was often left home by himself because his father was held captive in Siberia as an Austro-Hungarian prisoner of war during 1914–1920, causing his mot |
https://en.wikipedia.org/wiki/Nevi%20and%20melanomas | Nevi and melanomas are a group of neoplasia.
Although a nevus and a melanoma are often treated as independent entities, there is evidence that a nevus can be a precursor for a melanoma.
Common mutations have been identified in nevi and melanomas.
See also
List of cutaneous conditions |
https://en.wikipedia.org/wiki/Radeon%209000%20series | The R300 GPU, introduced in August 2002 and developed by ATI Technologies, is its third generation of GPU used in Radeon graphics cards. This GPU features 3D acceleration based upon Direct3D 9.0 and OpenGL 2.0, a major improvement in features and performance compared to the preceding R200 design. R300 was the first fully Direct3D 9-capable consumer graphics chip. The processors also include 2D GUI acceleration, video acceleration, and multiple display outputs.
The first graphics cards using the R300 to be released were the Radeon 9700. It was the first time that ATI marketed its GPU as a Visual Processing Unit (VPU). R300 and its derivatives would form the basis for ATI's consumer and professional product lines for over 3 years.
Radeon Feature Matrix
Radeon R200 (9xxx) series
AGP (9xxx series)
All models are manufactured with a 150 nm fabrication process
All models include DirectX 8.1 and OpenGL 1.4
1 Pixel shaders : Vertex shaders : Texture mapping units : Render output units
IGP (9xxx series)
All models are manufactured with a 150 nm fabrication process
All models include DirectX 8.1 and OpenGL 1.4
Based on the Radeon 9200
1 Pixel shaders : Vertex shaders : Texture mapping units : Render output units
Radeon R300 series
AGP (9xxx series)
All models include DirectX 9.0 and OpenGL 2.0
1 Pixel shaders : Vertex shaders : Texture mapping units : Render output units
2 The 256-bit version of the 9800 SE when unlocked to 8-pixel pipelines with third party driver modifications should function close to a full 9800 Pro.
Development
ATI had held the lead for a while with the Radeon 8500 but NVIDIA retook the performance crown with the launch of the GeForce 4 Ti line. A new high-end refresh part, the 8500XT (R250) was supposedly in the works, ready to compete against NVIDIA's high-end offerings, particularly the top line Ti 4600. Pre-release information listed a 300 MHz core and RAM clock speed for the R250 chip. ATI, perhaps mindful of what had happen |
https://en.wikipedia.org/wiki/Enucleation%20%28microbiology%29 | In the context of microbiology, enucleation refers to removing the nucleus of a cell and replacing it with a different nucleus. This is used mainly in cloning but can also be used for creating hybrids of plants or animals.
List of enucleated cells
Humans
Red blood cell
Platelets
See also
Cytoplasmic hybrid
Cell nucleus |
https://en.wikipedia.org/wiki/Galveston%20National%20Laboratory | The Galveston National Laboratory (GNL) in Galveston, Texas, United States, is a high security National Biocontainment Laboratory housing several Biosafety level 4 research laboratories. The lab is run by the University of Texas Medical Branch (UTMB) for exotic disease diagnosis and research. The GNL is one of the 15 biosecurity level 4 facilities in the United States and the largest one in the world located on an academic campus.
History
In the early 2000s, several incidents in the U.S. led to the federal government pushing for the creation of more facilities to provide research to help defend against bioterrorism attacks. Under the direction of the U.S. Congress, the National Institutes of Health (NIH) began a nationwide search for a location to build a National Biocontainment Laboratory. In 2003, UTMB was chosen by the NIH as the site for one of two such national laboratories, and a $174 million federal grant was issued to pay for its construction. The Galveston National Laboratory is one of only two such facilities in the United States. The other one is the National Emerging Infectious Diseases Laboratories (NEIDL). In 2020, the United States Department of Education launched an investigation of the Galveston National Laboratory regarding any past interaction with the Wuhan Institute of Virology.
Statistics
Galveston National Laboratory is an eight-story structure that was built using construction standards designed to resist a Category 5 hurricane. In addition to structural design elements, other protective measures included support pilings reaching a depth of into the earth and the placement of all lab facilities at a height of at least above the 100-year floodplain.
The building houses more than of laboratory space, of which is dedicated to BSL-4 use. Other labs located in the building include BSL-3 facilities which research select & non-select agents in cell cultures, animal and insects. The laboratory became operational in November 2008 and was dedi |
https://en.wikipedia.org/wiki/Microecology | Microecology means microbial ecology or ecology of a microhabitat. In humans, gut microecology is the study of the microbial ecology of the human gut which includes gut microbiota composition, its metabolic activity, and the interactions between the microbiota, the host, and the environment. Research in human gut microecology is important because the microbiome can have profound effects on human health. The microbiome is known to influence the immune system, digestion, and metabolism, and is thought to play a role in a variety of diseases, including diabetes, obesity, inflammatory bowel disease, and cancer. Studying the microbiome can help us better understand these diseases and develop treatments.
Microecology is a large field that includes many topics such as; evolution, biodiversity, exobiology, ecology, bioremediation, recycling, and food microbiology. It is the study of the interactions between living organisms and their environment, and how these interactions affect the organisms and their environment. Additionally, it is a multidisciplinary area of study, combining elements of biology, chemistry, physics, and mathematics. It focuses on the study of the interactions between microorganisms and the environment they inhabit, their effects on the environment, and their effects on other organisms. Microecology also studies the effects of human activity on the environment and how this affects the growth and development of microorganisms. Microecology has many applications in the fields of medicine, agriculture, and biotechnology. It is also important for understanding the cycling of nutrients in the environment, and the behavior of microorganisms in various environments.
Moving onwards Intestinal microecology is a new area of microecology study. It is a complex microflora that is directly related to human health. Therefore, regulation of intestinal microecology will help in the treatment of many diseases. It was reported that intestinal flora is involved in anti-t |
https://en.wikipedia.org/wiki/Vanishing%20point | A vanishing point is a point on the image plane of a perspective rendering where the two-dimensional perspective projections of mutually parallel lines in three-dimensional space appear to converge. When the set of parallel lines is perpendicular to a picture plane, the construction is known as one-point perspective, and their vanishing point corresponds to the oculus, or "eye point", from which the image should be viewed for correct perspective geometry. Traditional linear drawings use objects with one to three sets of parallels, defining one to three vanishing points.
Italian humanist polymath and architect Leon Battista Alberti first introduced the concept in his treatise on perspective in art, De pictura, written in 1435.
Vector notation
The vanishing point may also be referred to as the "direction point", as lines having the same directional vector, say D, will have the same vanishing point. Mathematically, let be a point lying on the image plane, where is the focal length (of the camera associated with the image), and let be the unit vector associated with , where . If we consider a straight line in space with the unit vector and its vanishing point , the unit vector associated with is equal to , assuming both point towards the image plane.
When the image plane is parallel to two world-coordinate axes, lines parallel to the axis that is cut by this image plane will have images that meet at a single vanishing point. Lines parallel to the other two axes will not form vanishing points as they are parallel to the image plane. This is one-point perspective. Similarly, when the image plane intersects two world-coordinate axes, lines parallel to those planes will meet form two vanishing points in the picture plane. This is called two-point perspective. In three-point perspective the image plane intersects the , , and axes and therefore lines parallel to these axes intersect, resulting in three different vanishing points.
Theorem
The vanishing point theo |
https://en.wikipedia.org/wiki/Livermore%20Time%20Sharing%20System | The Livermore Time Sharing System (LTSS) was a supercomputer operating system originally developed by the Lawrence Livermore Laboratories for the Control Data Corporation 6600 and 7600 series of supercomputers in 1965.
LTSS resulted in the Cray Time Sharing System and then the Network Livermore Timesharing System (NLTSS).
See also
UNICOS |
https://en.wikipedia.org/wiki/Copper%20indium%20gallium%20selenide | Copper indium gallium (di)selenide (CIGS) is a I-III-VI2 semiconductor material composed of copper, indium, gallium, and selenium. The material is a solid solution of copper indium selenide (often abbreviated "CIS") and copper gallium selenide. It has a chemical formula of CuIn1−xGaxSe2, where the value of x can vary from 0 (pure copper indium selenide) to 1 (pure copper gallium selenide). CIGS is a tetrahedrally bonded semiconductor, with the chalcopyrite crystal structure, and a bandgap varying continuously with x from about 1.0 eV (for copper indium selenide) to about 1.7 eV (for copper gallium selenide).
Structure
CIGS is a tetrahedrally bonded semiconductor, with the chalcopyrite crystal structure. Upon heating it transforms to the zincblende form and the transition temperature decreases from 1045 °C for x = 0 to 805 °C for x = 1.
Applications
It is best known as the material for CIGS solar cells a thin-film technology used in the photovoltaic industry. In this role, CIGS has the advantage of being able to be deposited on flexible substrate materials, producing highly flexible, lightweight solar panels. Improvements in efficiency have made CIGS an established technology among alternative cell materials.
See also
Copper indium gallium selenide solar cells
CZTS
List of CIGS companies |
https://en.wikipedia.org/wiki/Ion%20source | An ion source is a device that creates atomic and molecular ions. Ion sources are used to form ions for mass spectrometers, optical emission spectrometers, particle accelerators, ion implanters and ion engines.
Electron ionization
Electron ionization is widely used in mass spectrometry, particularly for organic molecules. The gas phase reaction producing electron ionization is
M{} + e^- -> M^{+\bullet}{} + 2e^-
where M is the atom or molecule being ionized, e^- is the electron, and M^{+\bullet} is the resulting ion.
The electrons may be created by an arc discharge between a cathode and an anode.
An electron beam ion source (EBIS) is used in atomic physics to produce highly charged ions by bombarding atoms with a powerful electron beam. Its principle of operation is shared by the electron beam ion trap.
Electron capture ionization
Electron capture ionization (ECI) is the ionization of a gas phase atom or molecule by attachment of an electron to create an ion of the form A−•. The reaction is
A + e^- ->[M] A^-
where the M over the arrow denotes that to conserve energy and momentum a third body is required (the molecularity of the reaction is three).
Electron capture can be used in conjunction with chemical ionization.
An electron capture detector is used in some gas chromatography systems.
Chemical ionization
Chemical ionization (CI) is a lower energy process than electron ionization because it involves ion/molecule reactions rather than electron removal. The lower energy yields less fragmentation, and usually a simpler spectrum. A typical CI spectrum has an easily identifiable molecular ion.
In a CI experiment, ions are produced through the collision of the analyte with ions of a reagent gas in the ion source. Some common reagent gases include: methane, ammonia, and isobutane. Inside the ion source, the reagent gas is present in large excess compared to the analyte. Electrons entering the source will preferentially ionize the reagent gas. The res |
https://en.wikipedia.org/wiki/He%20Jiankui%20affair | The He Jiankui affair is a scientific and bioethical controversy concerning the use of genome editing following its first use on humans by Chinese scientist He Jiankui, who edited the genomes of human embryos in 2018. He became widely known on 26 November 2018 after he announced that he had created the first human genetically edited babies. He was listed in the Time's 100 most influential people of 2019. The affair led to ethical and legal controversies, resulting in the indictment of He and two of his collaborators, Zhang Renli and Qin Jinzhou. He eventually received widespread international condemnation.
He Jiankui, working at the Southern University of Science and Technology (SUSTech) in Shenzhen, China, started a project to help people with HIV-related fertility problems, specifically involving HIV-positive fathers and HIV-negative mothers. The subjects were offered standard in vitro fertilisation services and in addition, use of CRISPR gene editing (CRISPR/Cas9), a technology for modifying DNA. The embryos' genomes were edited to remove the CCR5 gene in an attempt to confer genetic resistance to HIV. The clinical project was conducted secretly until 25 November 2018, when MIT Technology Review broke the story of the human experiment based on information from the Chinese clinical trials registry. Compelled by the situation, he immediately announced the birth of genome-edited babies in a series of five YouTube videos the same day. The first babies, known by their pseudonyms Lulu () and Nana (), are twin girls born in October 2018, and the second birth or the third baby born was in 2019, named Amy. He reported that the babies were born healthy.
His actions received widespread criticism, and included concern for the girls' well-being. After his presentation on the research at the Second International Summit on Human Genome Editing at the University of Hong Kong on 28 November 2018, Chinese authorities suspended his research activities the following day. On 30 Dec |
https://en.wikipedia.org/wiki/ALTO%20%28protocol%29 | Application Layer Transport Optimization (ALTO) is a protocol that allows internet clients to obtain information that compares the network properties of paths to other endpoints. Typically, this would be used to identify the lowest-cost location to access a copy of some sort of content.
The ALTO base protocol is specified in RFC 7285. It requires "ALTO servers" to be deployed in the network with knowledge of network properties, often simply the routing cost to various endpoints. An "ALTO client," typically tied to a user agent attempting to obtain a resource, queries the ALTO server over HTTP to obtain the optimal location from which to retrieve the resource.
History
Starting around 2005, the widespread use of peer-to-peer applications such as BitTorrent was a serious concern to many network operators, as the massive amounts of network traffic caused by these applications
had a significant impact on traffic engineering and revenues. Some network operators tried to throttle this traffic.
In May 2008, in an IETF Workshop on Peer-to-Peer Infrastructure, several areas of work were identified:
A standardized interface for the exchange of information between the underlying IP network and an overlay network, such as a peer-to-peer network. The basic idea is, that if the overlay network was aware of the topology and the cost for sending traffic through the underlying IP network, it could optimize decisions with respect to the overlay network's topology (e.g., peer selection) and routing of traffic through the overlay network. The result would be better performance or Quality of Experience in the application while reducing the utilization of the underlying network infrastructure. This work item led to the establishment of the IETF ALTO working group.
Content caches in the network. This has been studied in the IETF DECADE working group. However, no new protocol has been developed and standardized.
A new congestion control mechanism in the transport layer for background tr |
https://en.wikipedia.org/wiki/Self-service%20password%20reset | Self-service password reset (SSPR) is defined as any process or technology that allows users who have either forgotten their password or triggered an intruder lockout to authenticate with an alternate factor, and repair their own problem, without calling the help desk. It is a common feature in identity management software and often bundled in the same software package as a password synchronization capability.
Typically users who have forgotten their password launch a self-service application from an extension to their workstation login prompt, using their own or another user's web browser, or through a telephone call. Users establish their identity, without using their forgotten or disabled password, by answering a series of personal questions, using a hardware authentication token, responding to a notification e-mail or, less often, by providing a biometric sample such as voice recognition. Users can then either specify a new, unlocked password, or ask that a randomly generated one be provided.
Self-service password reset expedites problem resolution for users "after the fact", and thus reduces help desk call volume. It can also be used to ensure that password problems are only resolved after adequate user authentication, eliminating an important weakness of many help desks: social engineering attacks, where an intruder calls the help desk, pretends to be the intended victim user, claims to have forgotten the account password, and asks for a new password.
Multi-factor authentication
Rather than merely asking users to answer security questions, modern password reset systems may also leverage a sequence of authentication steps:
Ask users to complete a CAPTCHA, to demonstrate that they are human.
Ask users to enter a PIN which is sent to their personal e-mail address or mobile phone.
Require use of another technology, such as a one-time-password token.
Leverage biometrics, such as a voice print.
An authenticator, such as Google Authenticator or an SMS code.
|
https://en.wikipedia.org/wiki/Intramolecular%20reaction | In chemistry, intramolecular describes a process or characteristic limited within the structure of a single molecule, a property or phenomenon limited to the extent of a single molecule.
Examples
intramolecular hydride transfer (transfer of a hydride ion from one part to another within the same molecule)
intramolecular hydrogen bond (a hydrogen bond formed between two functional groups of the same molecule)
cyclization of ω-haloalkylamines and alcohols to form the corresponding saturated nitrogen and oxygen heterocycles, respectively (an SN2 reaction within the same molecule)
In intramolecular organic reactions, two reaction sites are contained within a single molecule. This creates a very high effective concentration (resulting in high reaction rates), and, therefore, many intramolecular reactions that would not occur as an intermolecular reaction between two compounds take place.
Examples of intramolecular reactions are the Smiles rearrangement, the Dieckmann condensation and the Madelung synthesis.
Relative rates
Intramolecular reactions, especially ones leading to the formation of 5- and 6-membered rings, are rapid compared to an analogous intermolecular process. This is largely a consequence of the reduced entropic cost for reaching the transition state of ring formation and the absence of significant strain associated with formation of rings of these sizes. For the formation of different ring sizes via cyclization of substrates of varying tether length, the order of reaction rates (rate constants kn for the formation of an n-membered ring) is usually k5 > k6 > k3 > k7 > k4 as shown below for a series of ω-bromoalkylamines. This somewhat complicated rate trend reflects the interplay of these entropic and strain factors:
For the 'small rings' (3- and 4- membered), the slow rates is a consequence of angle strain experienced at the transition state. Although three-membered rings are more strained, formation of aziridine is faster than formation of azetidi |
https://en.wikipedia.org/wiki/Krylov%E2%80%93Bogoliubov%20averaging%20method | The Krylov–Bogolyubov averaging method (Krylov–Bogolyubov method of averaging) is a mathematical method for approximate analysis of oscillating processes in non-linear mechanics. The method is based on the averaging principle when the exact differential equation of the motion is replaced by its averaged version. The method is named after Nikolay Krylov and Nikolay Bogoliubov.
Various averaging schemes for studying problems of celestial mechanics were used since works of Gauss, Fatou, Delone, Hill. The importance of the contribution of Krylov and Bogoliubov is that they developed a general averaging approach and proved that the solution of the averaged system approximates the exact dynamics.
Background
Krylov–Bogoliubov averaging can be used to approximate oscillatory problems when a classical perturbation expansion fails. That is singular perturbation problems of oscillatory type, for example Einstein's correction to the perihelion precession of Mercury.
Derivation
The method deals with differential equations in the form
for a smooth function f along with appropriate initial conditions. The parameter ε is assumed to satisfy
If ε = 0 then the equation becomes that of the simple harmonic oscillator with constant forcing, and the general solution is
where A and B are chosen to match the initial conditions. The solution to the perturbed equation (when ε ≠ 0) is assumed to take the same
form, but now A and B are allowed to vary with t (and ε). If it is also assumed that
then it can be shown that A and B satisfy the differential equation:
where . Note that this equation is still exact — no approximation has been made as yet. The method of Krylov and Bogolyubov is to note that the functions A and B vary slowly
with time (in proportion to ε), so their dependence on can be (approximately) removed by averaging on the right hand side of the previous equation:
where and are held fixed during the integration. After solving this (possibly) simpler set of differentia |
https://en.wikipedia.org/wiki/Equable%20shape | A two-dimensional equable shape (or perfect shape) is one whose area is numerically equal to its perimeter. For example, a right angled triangle with sides 5, 12 and 13 has area and perimeter both have a unitless numerical value of 30.
Scaling and units
An area cannot be equal to a length except relative to a particular unit of measurement. For example, if shape has an area of 5 square yards and a perimeter of 5 yards, then it has an area of and a perimeter of 15 feet (since 3 feet = 1 yard and hence 9 square feet = 1 square yard). Moreover, contrary to what the name implies, changing the size while leaving the shape intact changes an "equable shape" into a non-equable shape. However its common use as GCSE coursework has led to its being an accepted concept. For any shape, there is a similar equable shape: if a shape S has perimeter p and area A, then scaling S by a factor of p/A leads to an equable shape. Alternatively, one may find equable shapes by setting up and solving an equation in which the area equals the perimeter. In the case of the square, for instance, this equation is
Solving this yields that x = 4, so a 4 × 4 square is equable.
Tangential polygons
A tangential polygon is a polygon in which the sides are all tangent to a common circle. Every tangential polygon may be triangulated by drawing edges from the circle's center to the polygon's vertices, forming a collection of triangles that all have height equal to the circle's radius; it follows from this decomposition that the total area of a tangential polygon equals half the perimeter times the radius. Thus, a tangential polygon is equable if and only if its inradius is two. All triangles are tangential, so in particular the equable triangles are exactly the triangles with inradius two.
Integer dimensions
Combining restrictions that a shape be equable and that its dimensions be integers is significantly more restrictive than either restriction on its own. For instance, there are infinitely many Pyt |
https://en.wikipedia.org/wiki/Defective%20pixel | A defective pixel is a pixel on a liquid crystal display (LCD) that is not functioning properly. The ISO standard ISO 13406-2 distinguishes between three different types of defective pixels, while hardware companies tend to have further distinguishing types.
Similar defects can also occur in charge-coupled device (CCD) and CMOS image sensors in digital cameras. In these devices, defective pixels fail to sense light levels correctly, whereas defective pixels in LCDs fail to reproduce light levels correctly.
Types
Dark dot defect
A dark dot defect is usually caused by a transistor in the transparent electrode layer that is stuck "on" for TN panels or "off" for MVA, PVA, and IPS panels. In that state, the liquid crystal material does not do any rotation so that the light from the backlight does not pass through the RGB layer of the display.
Bright dot defect
A bright dot defect or hot pixel is a group of three sub-pixels (one pixel) all of whose transistors are "off" for TN panels or stuck "on" for MVA and PVA panels. This allows all light to pass through to the RGB layer, creating a bright pixel that is always on.
Another cause of bright dot may be the presence of impurities in the liquid crystal. On the one hand, impurities will affect the alignment of liquid crystal molecules, and on the other hand, they can reflect light to form bright spots.
Partial sub-pixel defect
A partial sub-pixel defect is a manufacturing defect in which the RGB film layer was not cut properly.
Tape automated bonding fault
A tape automated bonding fault (TAB fault) is caused by a connection failure from the TAB that connects the transparent electrode layers to the video driver board of an LCD.
TAB is one of several methods employed in the LCD-manufacturing process to electrically connect hundreds of signal paths going to the rows and columns of electrodes in layer 6 (the transparent electrode layer) in the LCD to the video integrated circuits (ICs) on the driver board that drives th |
https://en.wikipedia.org/wiki/Allylic%20strain | Allylic strain (also known as A1,3 strain, 1,3-allylic strain, or A-strain) in organic chemistry is a type of strain energy resulting from the interaction between a substituent on one end of an olefin (a synonym for an alkene) with an allylic substituent on the other end. If the substituents (R and R') are large enough in size, they can sterically interfere with each other such that one conformer is greatly favored over the other. Allylic strain was first recognized in the literature in 1965 by Johnson and Malhotra. The authors were investigating cyclohexane conformations including endocyclic and exocylic double bonds when they noticed certain conformations were disfavored due to the geometry constraints caused by the double bond. Organic chemists capitalize on the rigidity resulting from allylic strain for use in asymmetric reactions.
Quantifying allylic strain energy
The "strain energy" of a molecule is a quantity that is difficult to precisely define, so the meaning of this term can easily vary depending on one's interpretation. Instead, an objective way to view the allylic strain of a molecule is through its conformational equilibrium. Comparing the heats of formation of the involved conformers, an overall ΔHeq can be evaluated. This term gives information about the relative stabilities of the involved conformers and the effect allylic strain has one equilibrium. Heats of formation can be determined experimentally though calorimetric studies; however, calculated enthalpies are more commonly used due to the greater ease of acquisition.
Different methods utilized to estimate conformational equilibrium enthalpy include: the Westheimer method, the homomorph method, and more simply—using estimated enthalpies of nonbonded interactions within a molecule. Because all of these methods are approximations, reported strain values for the same molecule can vary and should be used only to give a general idea of the strain energy.
Olefins
The simplest type of molecules |
https://en.wikipedia.org/wiki/Burke%20and%20Hare%20murders | The Burke and Hare murders were a series of sixteen killings committed over a period of about ten months in 1828 in Edinburgh, Scotland. They were undertaken by William Burke and William Hare, who sold the corpses to Robert Knox for dissection at his anatomy lectures.
Edinburgh was a leading European centre of anatomical study in the early 19th century, in a time when the demand for cadavers led to a shortfall in legal supply. Scottish law required that corpses used for medical research should only come from those who had died in prison, suicide victims, or from foundlings and orphans. The shortage of corpses led to an increase in body snatching by what were known as "resurrection men". Measures to ensure graves were left undisturbed—such as the use of mortsafes—exacerbated the shortage. When a lodger in Hare's house died, he turned to his friend Burke for advice and they decided to sell the body to Knox. They received what was, for them, the generous sum of £7 10s. A little over two months later, when Hare was concerned that a lodger with a fever would deter others from staying in the house, he and Burke murdered her and sold the body to Knox. The men continued their murder spree, probably with the knowledge of their wives. Burke and Hare's actions were uncovered after other lodgers discovered their last victim, Margaret Docherty, and contacted the police.
A forensic examination of Docherty's body indicated she had probably been suffocated, but this could not be proven. Although the police suspected Burke and Hare of other murders, there was no evidence on which they could take action. An offer was put to Hare granting immunity from prosecution if he turned king's evidence. He provided the details of Docherty's murder and confessed to all sixteen deaths; formal charges were made against Burke and his wife for three murders. At the subsequent trial Burke was found guilty of one murder and sentenced to death. The case against his wife was found not proven—a Scottis |
https://en.wikipedia.org/wiki/Ant%20colony%20optimization%20algorithms | In computer science and operations research, the ant colony optimization algorithm (ACO) is a probabilistic technique for solving computational problems which can be reduced to finding good paths through graphs. Artificial ants stand for multi-agent methods inspired by the behavior of real ants.
The pheromone-based communication of biological ants is often the predominant paradigm used. Combinations of artificial ants and local search algorithms have become a method of choice for numerous optimization tasks involving some sort of graph, e.g., vehicle routing and internet routing.
As an example, ant colony optimization is a class of optimization algorithms modeled on the actions of an ant colony. Artificial 'ants' (e.g. simulation agents) locate optimal solutions by moving through a parameter space representing all possible solutions. Real ants lay down pheromones directing each other to resources while exploring their environment. The simulated 'ants' similarly record their positions and the quality of their solutions, so that in later simulation iterations more ants locate better solutions. One variation on this approach is the bees algorithm, which is more analogous to the foraging patterns of the honey bee, another social insect.
This algorithm is a member of the ant colony algorithms family, in swarm intelligence methods, and it constitutes some metaheuristic optimizations. Initially proposed by Marco Dorigo in 1992 in his PhD thesis, the first algorithm was aiming to search for an optimal path in a graph, based on the behavior of ants seeking a path between their colony and a source of food. The original idea has since diversified to solve a wider class of numerical problems, and as a result, several problems have emerged, drawing on various aspects of the behavior of ants. From a broader perspective, ACO performs a model-based search and shares some similarities with estimation of distribution algorithms.
Overview
In the natural world, ants of some |
https://en.wikipedia.org/wiki/Janos%20Galambos | Janos Galambos (Galambos János in Hungarian, 1 September 1940 – 19 December 2019) was a Hungarian mathematician affiliated with Temple University in Philadelphia, Pennsylvania, USA.
Education and career
Galambos earned his Ph.D. in 1963 from Eötvös Loránd University, under the supervision of Alfréd Rényi. He remained at the Eötvös Loránd University as an assistant professor from 1964 to 1965. He was lecturer at the University of Ghana from 1965 to 1969 and at University of Ibadan from 1969 to 1970. In 1970, Galambos joined the faculty of Temple University in Philadelphia and remained there until his retirement in 2012.
Galambos worked on probability theory, number theory, order statistics, and many other sub-specialties, and published hundreds of papers and many books.
In 1993 he was elected external member of the Hungarian Academy of Sciences, and in 2001 he became a corresponding member of the Royal Academy of Engineering of Spain.
Selected books |
https://en.wikipedia.org/wiki/GPU%20switching | GPU switching is a mechanism used on computers with multiple graphic controllers. This mechanism allows the user to either maximize the graphic performance or prolong battery life by switching between the graphic cards. It is mostly used on gaming laptops which usually have an integrated graphic device and a discrete video card.
Basic components
Most computers using this feature contain integrated graphics processors and dedicated graphics cards that applies to the following categories.
Integrated graphics
Also known as: Integrated graphics, shared graphics solutions, integrated graphics processors (IGP) or unified memory architecture (UMA). This kind of graphics processors usually have much fewer processing units and share the same memory with the CPU.
Sometimes the graphics processors are integrated onto a motherboard. It is commonly known as: on-board graphics. A motherboard with on-board graphics processors doesn't require a discrete graphics card or a CPU with graphics processors to operate.
Dedicated graphics cards
Also known as: discrete graphics cards. Unlike integrated graphics, dedicated graphics cards have much more processing units and have its own RAM with much higher memory bandwidth.
In some cases, a dedicated graphics chip can be integrated onto the motherboards, B150-GP104 for example. Regardless of the fact that the graphics chip is integrated, it is still counted as a dedicated graphics cards system because the graphics chip is integrated with its own memory.
Theory
Most Personal Computers have a motherboard that uses a Southbridge and Northbridge structure.
Northbridge control
The Northbridge is one of the core logic chipset that handles communications between the CPU, GPU, RAM and the Southbridge. The discrete graphics card is usually installed onto the graphics card slot such as PCI-Express and the integrated graphics is integrated onto the CPU itself or occasionally onto the Northbridge. The Northbridge is the most responsible for s |
https://en.wikipedia.org/wiki/Cousin%20problems | In mathematics, the Cousin problems are two questions in several complex variables, concerning the existence of meromorphic functions that are specified in terms of local data. They were introduced in special cases by Pierre Cousin in 1895. They are now posed, and solved, for any complex manifold M, in terms of conditions on M.
For both problems, an open cover of M by sets Ui is given, along with a meromorphic function fi on each Ui.
First Cousin problem
The first Cousin problem or additive Cousin problem assumes that each difference
is a holomorphic function, where it is defined. It asks for a meromorphic function f on M such that
is holomorphic on Ui; in other words, that f shares the singular behaviour of the given local function. The given condition on the is evidently necessary for this; so the problem amounts to asking if it is sufficient. The case of one variable is the Mittag-Leffler theorem on prescribing poles, when M is an open subset of the complex plane. Riemann surface theory shows that some restriction on M will be required. The problem can always be solved on a Stein manifold.
The first Cousin problem may be understood in terms of sheaf cohomology as follows. Let K be the sheaf of meromorphic functions and O the sheaf of holomorphic functions on M. A global section of K passes to a global section of the quotient sheaf K/O. The converse question is the first Cousin problem: given a global section of K/O, is there a global section of K from which it arises? The problem is thus to characterize the image of the map
By the long exact cohomology sequence,
is exact, and so the first Cousin problem is always solvable provided that the first cohomology group H1(M,O) vanishes. In particular, by Cartan's theorem B, the Cousin problem is always solvable if M is a Stein manifold.
Second Cousin problem
The second Cousin problem or multiplicative Cousin problem assumes that each ratio
is a non-vanishing holomorphic function, where it is defined. It ask |
https://en.wikipedia.org/wiki/Fractal%20curve | A fractal curve is, loosely, a mathematical curve whose shape retains the same general pattern of irregularity, regardless of how high it is magnified, that is, its graph takes the form of a fractal. In general, fractal curves are nowhere rectifiable curves — that is, they do not have finite length — and every subarc longer than a single point has infinite length.
A famous example is the boundary of the Mandelbrot set.
Fractal curves in nature
Fractal curves and fractal patterns are widespread, in nature, found in such places as broccoli, snowflakes, feet of geckos, frost crystals, and lightning bolts.
See also Romanesco broccoli, dendrite crystal, trees, fractals, Hofstadter's butterfly, Lichtenberg figure, and self-organized criticality.
Dimensions of a fractal curve
Most of us are used to mathematical curves having dimension one, but as a general rule, fractal curves have different dimensions, also see fractal dimension and list of fractals by Hausdorff dimension.
Relationships of fractal curves to other fields
Starting in the 1950s Benoit Mandelbrot and others have studied self-similarity of fractal curves, and have applied theory of fractals to modelling natural phenomena. Self-similarity occurs, and analysis of these patterns has found fractal curves in such diverse fields as
economics,
fluid mechanics,
geomorphology
human physiology, and,
linguistics.
As examples, "landscapes" revealed by microscopic views of surfaces in connection with Brownian motion, vascular networks, and shapes of polymer molecules all relate to fractal curves.
Examples
Blancmange curve
Coastline paradox
De Rham curve
Dragon curve
Fibonacci word fractal
Koch snowflake
Boundary of the Mandelbrot set
Menger sponge
Peano curve
Sierpiński triangle
Trees
Natural fractals
Weierstrass function
See also
The Beauty of Fractals
Fractal antenna
Fractal expressionism
Fractal landscape
Hexaflake
Mosely snowflake
Newton fractal
Orbit trap
Quasicircle
The Frac |
https://en.wikipedia.org/wiki/Remmert%E2%80%93Stein%20theorem | In complex analysis, a field in mathematics, the Remmert–Stein theorem, introduced by , gives conditions for the closure of an analytic set to be analytic.
The theorem states that if F is an analytic set of dimension less than k in some complex manifold D, and M is an analytic subset of D – F with all components of dimension at least k, then the closure of M is either analytic or contains F.
The condition on the dimensions is necessary: for example, the set of points (1/n,0) in the complex plane is analytic in the complex plane minus the origin, but its closure in the complex plane is not.
Relations to other theorems
A consequence of the Remmert–Stein theorem (also treated in their paper), is Chow's theorem stating that any projective complex analytic space is necessarily a projective algebraic variety.
The Remmert–Stein theorem is implied by a proper mapping theorem due to , see . |
https://en.wikipedia.org/wiki/Algebraic%20normal%20form | In Boolean algebra, the algebraic normal form (ANF), ring sum normal form (RSNF or RNF), Zhegalkin normal form, or Reed–Muller expansion is a way of writing propositional logic formulas in one of three subforms:
The entire formula is purely true or false:
One or more variables are combined into a term by AND (), then one or more terms are combined by XOR () together into ANF. Negations are not permitted:
The previous subform with a purely true term:
Formulas written in ANF are also known as Zhegalkin polynomials and Positive Polarity (or Parity) Reed–Muller expressions (PPRM).
Common uses
ANF is a canonical form, which means that two logically equivalent formulas will convert to the same ANF, easily showing whether two formulas are equivalent for automated theorem proving. Unlike other normal forms, it can be represented as a simple list of lists of variable names—conjunctive and disjunctive normal forms also require recording whether each variable is negated or not. Negation normal form is unsuitable for determining equivalence, since on negation normal forms, equivalence does not imply equality: a ∨ ¬a is not reduced to the same thing as 1, even though they are logically equivalent.
Putting a formula into ANF also makes it easy to identify linear functions (used, for example, in linear-feedback shift registers): a linear function is one that is a sum of single literals. Properties of nonlinear-feedback shift registers can also be deduced from certain properties of the feedback function in ANF.
Performing operations within algebraic normal form
There are straightforward ways to perform the standard boolean operations on ANF inputs in order to get ANF results.
XOR (logical exclusive disjunction) is performed directly:
() ⊕ ()
⊕
1 ⊕ 1 ⊕ x ⊕ x ⊕ y
y
NOT (logical negation) is XORing 1:
1 ⊕ 1 ⊕ x ⊕ y
x ⊕ y
AND (logical conjunction) is distributed algebraically
( ⊕ )
⊕
(1 ⊕ x ⊕ y) ⊕ (x ⊕ x ⊕ xy)
1 ⊕ x ⊕ x ⊕ x ⊕ y ⊕ xy
1 ⊕ x ⊕ y ⊕ xy
|
https://en.wikipedia.org/wiki/Type%20B%20videotape | 1–inch type B VTR (designated Type B by SMPTE) is a reel-to-reel analog recording video tape format developed by the Bosch Fernseh division of Bosch in Germany in 1976. The magnetic tape format became the broadcasting standard in continental Europe, but adoption was limited in the United States and United Kingdom, where the Type C videotape VTR met with greater success.
Details
The tape speed allowed 96 minutes on a large reel (later 120 minutes), and used 2 record/playback (R/P) heads on the drum rotating at 9,000 RPM with a 190-degree wrap around a very small head drum, recording 52 video lines per head segment. A single video frame or field was recorded across 6 tracks in the tape. The format only allowed for play, rewind and fast forward. Video is recorded on an FM signal with a bandwidth of 5.5 MHz. Three longitudinal audio tracks are recorded on the tape as well: two audio and one Linear timecode (LTC) track. BCN 50 VTRs were used at the 1980 Summer Olympics in Moscow.
The format required an optional, and costly, digital framestore in addition to the normal analog timebase corrector to do any "trick-play" operations, such as slow motion/variable-speed playback, frame step play, and visible shuttle functions. This was because, unlike 1-inch type C which recorded one field per helical scan track on the tape, Type B segmented each field to 5 or 6 tracks per field according to whether it was a 525- (NTSC) or 625- (PAL) line machine.
The picture quality was excellent, and standard R/P machines, digital frame store machines, reel-to-reel portables, random access cart machines (for playback of short-form video material such as television commercials), and portable cart versions were marketed.
Echo Science Corporation, a United States company, made units like a BCN 1 for the U.S. military for a short time in the 1970s. Echo Science models were Pilot 1, Echo 460, Pilot 260.
Models introduced
BCR (BCR-40, BCR-50 and BCR-60) was a pre BCN VTR, made jointly with Phil |
https://en.wikipedia.org/wiki/Cell%20theory | In biology, cell theory is a scientific theory first formulated in the mid-nineteenth century, that organisms are made up of cells, that they are the basic structural/organizational unit of all organisms, and that all cells come from pre-existing cells. Cells are the basic unit of structure in all organisms and also the basic unit of reproduction.
The theory was once universally accepted, but now some biologists consider non-cellular entities such as viruses living organisms, and thus disagree with the first tenet. As of 2021: "expert opinion remains divided roughly a third each between yes, no and don’t know". As there is no universally accepted definition of life, discussion still continues.
History
With continual improvements made to microscopes over time, magnification technology became advanced enough to discover cells. This discovery is largely attributed to Robert Hooke, and began the scientific study of cells, known as cell biology. When observing a piece of cork under the scope, he was able to see pores. This was shocking at the time as it was believed no one else had seen these. To further support his theory, Matthias Schleiden and Theodor Schwann both also studied cells of both animal and plants. What they discovered were significant differences between the two types of cells. This put forth the idea that cells were not only fundamental to plants, but animals as well.
Microscopes
The discovery of the cell was made possible through the invention of the microscope. In the first century BC, Romans were able to make glass. They discovered that objects appeared to be larger under the glass. The expanded use of lenses in eyeglasses in the 13th century probably led to wider spread use of simple microscopes (magnifying glasses) with limited magnification. Compound microscopes, which combine an objective lens with an eyepiece to view a real image achieving much higher magnification, first appeared in Europe around 1620. In 1665, Robert Hooke used a microscope |
https://en.wikipedia.org/wiki/Pierella%20nereis | Pierella nereis is a butterfly species from the subfamily Satyrinae in the family Nymphalidae. It was first described by Dru Drury in 1782 from Brazil.
Description
Upperside: Antennae black. Head, thorax, abdomen grey brown. Anterior wings grey brown, thin, and slightly diaphanous, with a small light-coloured bar running from the anterior edge near the tips to the posterior. Posterior wings having one-third next the body grey brown, divided by a line drawn across the wings from the anterior to the abdominal edges; next to this is an angulated white patch, the rest of these wings being orange coloured, with two black eyespots, having white centres, placed one at the upper, the other at the abdominal corners, the former having a small white spot joining to its upper part. The edges of these wings are bordered with dark brown.
Underside: Palpi, legs, breast, and abdomen cream coloured. Anterior wings next the tips tinged with red brown; the remainder of the wings being of the same colour as on the upperside. Posterior wings next the body pale clay, which occupies half the wings; below which is a white bar, the remainder of the wings being dark orange: the two black eyespots are very small on this side, and the white spot above them not so distinct. These wings are larger than is generally observed among insects of this tribe, and are dentated, the anterior ones being entire. Wingspan 3 inches (76 mm). |
https://en.wikipedia.org/wiki/Larner%E2%80%93Johnson%20valve | A Larner–Johnson valve is a mechanism used in dams and water pumping to control the flow of water through large pipes. The valve is suited to handling high velocity flow with minimal turbulence, even when partially open, and the actuating force can be provided by the water flow it is controlling. It was manufactured in the early 20th century by the Larner-Johnson Company in the US. The valves are still manufactured in the United Kingdom by Blackhall Engineering Ltd. These valves have been constructed in sizes up to diameter and controlling a hydraulic head of .
In 2009, Blackhall Engineering supplied four 60" bore Larner–Johnson valves to New York City Department of Environmental Protection for the Ashokan Reservoir in upstate New York. Each valve is capable of passing a flow rate of 19 cubic metres/second, which is the equivalent of 19 tons of water per second. The valves control the flow of water out of the Ashokan Reservoir into the Catskill Aqueduct down to New York City.
Operation
The valve is housed within a bulged section of the penstock pipe. The valve mechanism forms a cylindrical body within this pipe, with the water flowing around it. This downstream section of this valve body is conical and free to move axially. When it moves downstream, it seals against a conical surface at the outlet of the valve, closing off the flow. When closed, the valve is held shut by the supply water pressure, providing a good seal.
The valve is hydraulically actuated, by the pressure of the flow that it is controlling. A servomechanism is used to generate the large forces needed for these huge valves, power being derived from the pressure of the water itself. Although the pressure within the pipe cannot be increased above that of the supply, it can be decreased. The pipe cross-section at the lower (downstream) part of the valve is reduced in section compared to that above the valve. By Bernoulli's principle, this increases the flow velocity of the water, thus reducing p |
https://en.wikipedia.org/wiki/National%20Quantum%20Mission%20India | National Quantum Mission India is an initiative by the Department of Science and Technology, Government of India, to foster quantum technologies related scientific and industrial research and development to accelerate economic growth to establish India as a global leader in quantum technology and applications and support national Digital India, Make India, Skill India and Sustainable development goals.
Background
The union cabinet of Government of India approved the National Quantum Mission with a cost of INR 6003.65 cr ($730,297,000) from 2023–24 to 2030–31. |
https://en.wikipedia.org/wiki/Brass%20model | Brass models, made of brass or similar alloys, are scale models typically of railroad equipment, bridges and occasionally, of buildings. Although die-cast or plastic models have made considerable advances in late 1990s and continue to improve, brass models offer finer details. Brass models, considered to be collector's pieces and museum quality finish, are often used for display purposes rather than model railroad operations. However, these can be made fully operational and many railroaders do use them on their model railroads. They are generally considerably more expensive than other types of models due to limited production quantities and the "handmade" nature of the product itself.
History
In the late 1950s, Japan was known for producing low cost toys and products for export. The first brass model train were born during the occupation of Japan by Allied forces. Members of allied forces saw some of the models built by various craftsman and procured photos of American steam locomotive prototypes for these artisans to model. These were the early hand-built high quality brass models, built with relatively crude equipment in comparison to tools that became available later. Some people in the model railroad industry took note of what was being done and started importing these models to the United States. The scale of import increased with time. Bill Ryan of PFM (Pacific Fast Mail) was one of the early importers, and to this day the name PFM is synonymous with brass model trains.
The quality of Japanese models continued to improve but with an improving domestic economy, manufacturing cost also increased. Eventually, importers moved their operations to Korea for cost benefits. Although the quality suffered considerably in the early years of this transition, within a few years some very fine brass models were being built. Korea continues to produce fine models; Boo-Rim Precision of Korea is among the most renowned producers of brass models.
Thousands of brass model tr |
https://en.wikipedia.org/wiki/Leibniz%27s%20notation | In calculus, Leibniz's notation, named in honor of the 17th-century German philosopher and mathematician Gottfried Wilhelm Leibniz, uses the symbols and to represent infinitely small (or infinitesimal) increments of and , respectively, just as and represent finite increments of and , respectively.
Consider as a function of a variable , or = . If this is the case, then the derivative of with respect to , which later came to be viewed as the limit
was, according to Leibniz, the quotient of an infinitesimal increment of by an infinitesimal increment of , or
where the right hand side is Joseph-Louis Lagrange's notation for the derivative of at . The infinitesimal increments are called . Related to this is the integral in which the infinitesimal increments are summed (e.g. to compute lengths, areas and volumes as sums of tiny pieces), for which Leibniz also supplied a closely related notation involving the same differentials, a notation whose efficiency proved decisive in the development of continental European mathematics.
Leibniz's concept of infinitesimals, long considered to be too imprecise to be used as a foundation of calculus, was eventually replaced by rigorous concepts developed by Weierstrass and others in the 19th century. Consequently, Leibniz's quotient notation was re-interpreted to stand for the limit of the modern definition. However, in many instances, the symbol did seem to act as an actual quotient would and its usefulness kept it popular even in the face of several competing notations. Several different formalisms were developed in the 20th century that can give rigorous meaning to notions of infinitesimals and infinitesimal displacements, including nonstandard analysis, tangent space, O notation and others.
The derivatives and integrals of calculus can be packaged into the modern theory of differential forms, in which the derivative is genuinely a ratio of two differentials, and the integral likewise behaves in exact accordance w |
https://en.wikipedia.org/wiki/Common%20descent | Common descent is a concept in evolutionary biology applicable when one species is the ancestor of two or more species later in time. According to modern evolutionary biology, all living beings could be descendants of a unique ancestor commonly referred to as the last universal common ancestor (LUCA) of all life on Earth.
Common descent is an effect of speciation, in which multiple species derive from a single ancestral population. The more recent the ancestral population two species have in common, the more closely are they related. The most recent common ancestor of all currently living organisms is the last universal ancestor, which lived about 3.9 billion years ago. The two earliest pieces of evidence for life on Earth are graphite found to be biogenic in 3.7 billion-year-old metasedimentary rocks discovered in western Greenland and microbial mat fossils found in 3.48 billion-year-old sandstone discovered in Western Australia. All currently living organisms on Earth share a common genetic heritage, though the suggestion of substantial horizontal gene transfer during early evolution has led to questions about the monophyly (single ancestry) of life. 6,331 groups of genes common to all living animals have been identified; these may have arisen from a single common ancestor that lived 650 million years ago in the Precambrian.
Universal common descent through an evolutionary process was first proposed by the British naturalist Charles Darwin in the concluding sentence of his 1859 book On the Origin of Species:
History
The idea that all living things (including things considered non-living by science) are related is a recurring theme in many indigenous worldviews across the world. Later on, in the 1740s, the French mathematician Pierre Louis Maupertuis arrived at the idea that all organisms had a common ancestor, and had diverged through random variation and natural selection. In Essai de cosmologie (1750), Maupertuis noted:
May we not say that, in the fortuito |
https://en.wikipedia.org/wiki/Conformal%20radius | In mathematics, the conformal radius is a way to measure the size of a simply connected planar domain D viewed from a point z in it. As opposed to notions using Euclidean distance (say, the radius of the largest inscribed disk with center z), this notion is well-suited to use in complex analysis, in particular in conformal maps and conformal geometry.
A closely related notion is the transfinite diameter or (logarithmic) capacity of a compact simply connected set D, which can be considered as the inverse of the conformal radius of the complement E = Dc viewed from infinity.
Definition
Given a simply connected domain D ⊂ C, and a point z ∈ D, by the Riemann mapping theorem there exists a unique conformal map f : D → D onto the unit disk (usually referred to as the uniformizing map) with f(z) = 0 ∈ D and f′(z) ∈ R+. The conformal radius of D from z is then defined as
The simplest example is that the conformal radius of the disk of radius r viewed from its center is also r, shown by the uniformizing map x ↦ x/r. See below for more examples.
One reason for the usefulness of this notion is that it behaves well under conformal maps: if φ : D → D′ is a conformal bijection and z in D, then .
The conformal radius can also be expressed as where is the harmonic extension of from to .
A special case: the upper-half plane
Let K ⊂ H be a subset of the upper half-plane such that D := H\K is connected and simply connected, and let z ∈ D be a point. (This is a usual scenario, say, in the Schramm-Loewner evolution). By the Riemann mapping theorem, there is a conformal bijection g : D → H. Then, for any such map g, a simple computation gives that
For example, when K = ∅ and z = i, then g can be the identity map, and we get rad(i, H) = 2. Checking that this agrees with the original definition: the uniformizing map f : H → D is
and then the derivative can be easily calculated.
Relation to inradius
That it is a good measure of radius is shown by the following immediate |
https://en.wikipedia.org/wiki/World%20Ocean%20Review | The World Ocean Review is a comprehensive report, now comprising seven volumes, about the state of the world’s oceans and the interactions between the ocean and ecological, economic and sociopolitical conditions. It aims to inform the general public about marine conservation. The World Ocean Review is produced in German and English. The print editions are published by maribus, a non-profit company founded by Nikolaus Gelpke as part of the mareverlag publishing house. All the reports are available for free download in PDF format on the project website or can be ordered at no cost online.
Content
The content of the World Ocean Review reflects the current state of scientific knowledge; this is achieved through intensive cooperation with the Kiel-based Cluster of Excellence “The Future Ocean”, the International Ocean Institute in Malta and the publisher, mareverlag. The German Marine Research Consortium (KDM) has been involved as a partner since the fifth edition. The topics covered in the World Ocean Review are closely aligned to the partner institutes’ own areas of research. Each topic is presented in clear and accessible language and visuals. The reports cover a range of specialist topics, from an introduction to the Earth’s climate system to fossil fuels from the ocean and the international law of the sea. The overarching theme of the work as a whole is: “Living with the oceans”.
Many national and international researchers have summarised numerous studies from the fields of climate and marine research in the reports. The World Ocean Review was published for the first time in 2010 and appears at regular intervals. The sound scientific information provided in the report is intended to be useful for anyone wishing to make an active and factual contribution to the current debate around marine research.
The first edition of the World Ocean Review explored general topics relating to the ocean. Volumes 2 to 6 focus on more specialised issues of relevance to the marin |
https://en.wikipedia.org/wiki/1-Click | 1-Click, also called one-click or one-click buying, is the technique of allowing customers to make purchases with the payment information needed to complete the purchase having been entered by the user previously. More particularly, it allows an online shopper using an Internet marketplace to purchase an item without having to use shopping cart software. Instead of manually inputting billing and shipping information for a purchase, a user can use one-click buying to use a predefined address and credit card number to purchase one or more items. Since the expiration of Amazon's patent, there has been an advent of checkout experience platforms, such as ShopPay, Simpler, PeachPay, Zplit, and Bolt which offer similar one-click checkout flows.
Patent
The United States Patent and Trademark Office (USPTO) issued a patent for this technique to Amazon.com in September 1999. Amazon.com also owns the "1-Click" trademark.
On May 12, 2006, the USPTO ordered a reexamination of the "One-Click" patent, based on a request filed by Peter Calveley. Calveley cited as prior art an earlier e-commerce patent and the Digicash electronic cash system.
On October 9, 2007, the USPTO issued an office action in the reexamination which confirmed the patentability of claims 6 to 10 of the patent. The patent examiner, however, rejected claims 1 to 5 and 11 to 26. In November 2007, Amazon responded by amending the broadest claims (1 and 11) to restrict them to a shopping cart model of commerce. They have also submitted several hundred references for the examiner to consider. In March 2010, the reexamined and amended patent was allowed.
Amazon's U.S. patent expired on September 11, 2017.
In Europe, a patent application on 1-Click ordering was filed with the European Patent Office (EPO) but was rejected by the EPO in 2007 due to obviousness; the decision was upheld in 2011.
A related gift-ordering patent was granted in 2003, but revoked in 2007 following an opposition.
In Canada, the Federal Co |
https://en.wikipedia.org/wiki/Median%20arcuate%20ligament | The median arcuate ligament is a ligament under the diaphragm that connects the right and left crura of diaphragm.
Structure
The median arcuate ligament is formed by the right and left crura of the diaphragm. The crura connect to form an arch, behind which is the aortic hiatus, through which pass the aorta, the azygos vein, and the thoracic duct.
Variation
In between 10% and 24% of people, the median arcuate ligament occurs very low.
Clinical significance
Compression of celiac artery and celiac ganglia by the median arcuate ligament can lead to the median arcuate ligament syndrome, which is characterized by abdominal pain, weight loss, and an epigastric bruit.
See also
Medial arcuate ligament
Lateral arcuate ligament |
https://en.wikipedia.org/wiki/Great%20Debate%20%28astronomy%29 | The Great Debate, also called the Shapley–Curtis Debate, was held on 26 April 1920 at the Smithsonian Museum of Natural History, between the astronomers Harlow Shapley and Heber Curtis. It concerned the nature of so-called spiral nebulae and the size of the universe. Shapley believed that these nebulae were relatively small and lay within the outskirts of the Milky Way galaxy (then thought to be the entire universe), while Curtis held that they were in fact independent galaxies, implying that they were exceedingly large and distant.
The two scientists first presented independent technical papers about "The Scale of the Universe" during the day and then took part in a joint discussion that evening. Much of the lore of the Great Debate grew out of two papers published by Shapley and by Curtis in the May 1921 issue of the Bulletin of the National Research Council. The published papers each included counterarguments to the position advocated by the other scientist at the 1920 meeting.
In the aftermath of the public debate, scientists have been able to verify individual pieces of evidence from both astronomers, but on the main point of the existence of other galaxies, Curtis has been proven correct.
Arguments
Shapley was arguing in favor of the Milky Way as the entirety of the universe. He believed that "spiral nebulae" such as Andromeda were simply part of the Milky Way. He could back up this claim by citing relative sizes—if Andromeda were not part of the Milky Way, then its distance must have been on the order of 108 light years—a span most contemporary astronomers would not accept. Adriaan van Maanen, a well-respected astronomer of the time, also provided evidence supporting Shapley's argument. Van Maanen claimed he had observed the Pinwheel Galaxy rotating, and that if the Pinwheel Galaxy were in fact a distinct galaxy and could be observed to be rotating on a timescale of years, its orbital velocity would be enormous and there would be a violation of the univers |
https://en.wikipedia.org/wiki/Aunt%20Jemima | Aunt Jemima was an American breakfast brand for pancake mix, table syrup, and other breakfast food products. The original version of the pancake mix was developed in 1888–1889 by the Pearl Milling Company and was advertised as the first "ready-mix" cooking product.
Aunt Jemima was modeled after, and has been a famous example of, the "Mammy" archetype in the Southern United States. Due to the "Mammy" stereotype's historical ties to the Jim Crow era, Quaker Oats announced in June 2020 that the Aunt Jemima brand would be discontinued "to make progress toward racial equality", leading to the Aunt Jemima image being removed by the fourth quarter of 2020.
In June 2021, the Aunt Jemima brand name was discontinued by its current owner, PepsiCo, with all products rebranded to Pearl Milling Company, the name of the company that produced the original pancake mix product. The Aunt Jemima name remains in use in the brand's tagline, "Same great taste as Aunt Jemima."
Nancy Green portrayed the Aunt Jemima character at the 1893 World's Columbian Exposition in Chicago and was one of the first Black corporate models in the United States. Subsequent advertising agencies hired dozens of actors to perform the role as the first organized sales promotion campaign.
History
In 1888, St. Joseph Gazette editor Chris L. Rutt and his friend Charles G. Underwood bought a small flour mill at 214 North 2nd St. in St. Joseph, Missouri. Rutt and Underwood's "Pearl Milling Company" produced a range of milled products (such as wheat flour and cornmeal) using a pearl milling process. Facing a glutted flour market, after a year of experimentation they began selling their excess flour in paper bags with the generic label "Self-Rising Pancake Flour" (later dubbed "the first ready-mix").
Branding and trademark
To distinguish their pancake mix, in late 1889 Rutt appropriated the Aunt Jemima name and image from lithographed posters seen at a vaudeville house in St. Joseph, Missouri.
In 1915, the well- |
https://en.wikipedia.org/wiki/Chlororespiration | Chlororespiration is a respiratory process that takes place within plants. Inside plant cells there is an organelle called the chloroplast which is surrounded by the thylakoid membrane. This membrane contains an enzyme called NAD(P)H dehydrogenase which transfers electrons in a linear chain to oxygen molecules. This electron transport chain (ETC) within the chloroplast also interacts with those in the mitochondria where respiration takes place. Photosynthesis is also a process that Chlororespiration interacts with. If photosynthesis is inhibited by environmental stressors like water deficit, increased heat, and/or increased/decreased light exposure, or even chilling stress then chlororespiration is one of the crucial ways that plants use to compensate for chemical energy synthesis.
Chlororespiration – the latest model
Initially, the presence of chlororespiration as a legitimate respiratory process in plants was heavily doubted. However, experimentation on Chlamydomonas reinhardtii, discovered Plastoquinone (PQ) to be a redox carrier. The role of this redox carrier is to transport electrons from the NAD(P)H enzyme to oxygen molecules on the thylakoid membrane. Using this cyclic electron chain around photosystem one (PS I), chlororespiration compensates for the lack of light. This cyclic pathway also allows electrons to re-enter the PQ pool through NAD(P)H enzyme activity and production, which is then used to supply ATP molecules (energy) to plant cells.
In the year 2002, the discovery of the molecules; plastid terminal oxidase (PTOX) and NDH complexes have revolutionised the concept of chlororespiration. Using evidence from experimentation on the plant species Rosa Meillandina, this latest model observes the role of PTOX to be an enzyme that prevents the PQ pool from over-reducing, by stimulating its reoxidation. Whereas, the NDH complexes are responsible for providing a gateway for electrons to form an ETC. The presence of such molecules are apparent in the non- |
https://en.wikipedia.org/wiki/Visual%20Component%20Library | The Visual Component Library (VCL) is a visual component-based object-oriented framework for developing the user interface of Microsoft Windows applications. It is written in Object Pascal.
History
The VCL was developed by Borland for use in, and is tightly integrated with, its Delphi and C++Builder RAD tools.
In 1995 Borland released Delphi, its first release of an Object Pascal IDE and language. Up until that point, Borland's Turbo Pascal for DOS and Windows was largely a procedural language, with minimal object-oriented features, and building UI frameworks with the language required using frameworks like Turbo Vision and Object Windows Library. OWL, a similar framework to MFC, required writing code to create UI objects.
A key aim of the VCL combined with the Delphi language was to change the requirements of building a user interface. (For context, the Delphi variant of Pascal had a number of innovative object-oriented features, such as properties and runtime type information, inspired by Modula and Smalltalk.) At the time, much UI code work required creating classes inheriting from other classes, and customized objects were often not reusable (for example, a button that performs a specific action cannot be reused in a different application.) UI code was also complicated, forcing the programmer to understand and use the Windows API, manage GDI resources, etc. Finally, a visual user interface arguably should be designed visually, and yet most tools to do so - at the time, mainly Visual Basic - did so in terms of the designer outputting code, creating a fragile, un-manually-editable situation - a problem that still persists today with many UI frameworks, particularly C++-based ones such as Qt.
The combination of the Delphi language and the VCL framework written in that language addressed these by:
A streaming framework, allowing an object and subobjects to be streamed to text or binary format - TComponent, the root class of the VCL framework
A form designe |
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