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JT (visualization format) Overview JT_(visualization_format) > Overview JT files are used in product lifecycle management (PLM) software programs and their respective CAD systems, by engineers and other professionals that need to analyze the geometry of complex products. The format and associated software is structured so that extremely large numbers of components can be quickly loaded, shaded and manipulated in real-time. Because all major 3D CAD formats are supported, a JT assembly can contain a mixture of any combination which has led to the term "multi-CAD". As JT is typically implemented as an integral part of a PLM solution, the resulting multi-CAD assembly is managed such that changes to the original CAD product definition files can be automatically synchronized with their associated JT files resulting in a multi-CAD assembly that is always up-to-date.
Mathematical symbol Calculus Table_of_mathematical_symbols > Calculus Quad, the 4-vector gradient operator or four-gradient, ( ∂ ∂ t , ∂ ∂ x , ∂ ∂ y , ∂ ∂ z ) {\displaystyle \textstyle \left({\frac {\partial }{\partial t}},{\frac {\partial }{\partial x}},{\frac {\partial }{\partial y}},{\frac {\partial }{\partial z}}\right)} . ◻ {\displaystyle \Box } or ◻ 2 {\displaystyle {\Box }^{2}} (here an actual box, not a placeholder) Denotes the d'Alembertian or squared four-gradient, which is a generalization of the Laplacian to four-dimensional spacetime. In flat spacetime with Euclidean coordinates, this may mean either − ∂ 2 ∂ t 2 + ∂ 2 ∂ x 2 + ∂ 2 ∂ y 2 + ∂ 2 ∂ z 2 {\displaystyle ~\textstyle -{\frac {\partial ^{2}}{\partial t^{2}}}+{\frac {\partial ^{2}}{\partial x^{2}}}+{\frac {\partial ^{2}}{\partial y^{2}}}+{\frac {\partial ^{2}}{\partial z^{2}}}~\;} or + ∂ 2 ∂ t 2 − ∂ 2 ∂ x 2 − ∂ 2 ∂ y 2 − ∂ 2 ∂ z 2 {\displaystyle \;~\textstyle +{\frac {\partial ^{2}}{\partial t^{2}}}-{\frac {\partial ^{2}}{\partial x^{2}}}-{\frac {\partial ^{2}}{\partial y^{2}}}-{\frac {\partial ^{2}}{\partial z^{2}}}~\;} ; the sign convention must be specified. In curved spacetime (or flat spacetime with non-Euclidean coordinates), the definition is more complicated. Also called box or quabla.
Biogeochemical cycling Summary Biogeochemical_cycling Changes to cycles can impact human health. The cycles are interconnected and play important roles regulating climate, supporting the growth of plants, phytoplankton and other organisms, and maintaining the health of ecosystems generally. Human activities such as burning fossil fuels and using large amounts of fertilizer can disrupt cycles, contributing to climate change, pollution, and other environmental problems.
Functionally graded material Applications Functionally_graded_material > Applications This is normally achieved by using a ceramic layer connected with a metallic layer. The Air Vehicles Directorate has conducted a Quasi-static bending test results of functionally graded titanium/titanium boride test specimens which can be seen below. The test correlated to the finite element analysis (FEA) using a quadrilateral mesh with each element having its own structural and thermal properties.
Chaotic hysteresis Summary Chaotic_hysteresis A nonlinear dynamical system exhibits chaotic hysteresis if it simultaneously exhibits chaotic dynamics (chaos theory) and hysteresis. As the latter involves the persistence of a state, such as magnetization, after the causal or exogenous force or factor is removed, it involves multiple equilibria for given sets of control conditions. Such systems generally exhibit sudden jumps from one equilibrium state to another (sometimes amenable to analysis using catastrophe theory). If chaotic dynamics appear either prior to or just after such jumps, or are persistent throughout each of the various equilibrium states, then the system is said to exhibit chaotic hysteresis. Chaotic dynamics are irregular and bounded and subject to sensitive dependence on initial conditions.
Hollow matrix Diagonal entries all zero Hollow_matrix > Definitions > Diagonal entries all zero A hollow matrix may be a square matrix whose diagonal elements are all equal to zero. That is, an n × n matrix A = (aij) is hollow if aij = 0 whenever i = j (i.e. aii = 0 for all i). The most obvious example is the real skew-symmetric matrix. Other examples are the adjacency matrix of a finite simple graph, and a distance matrix or Euclidean distance matrix. In other words, any square matrix that takes the form ( 0 ∗ ∗ ∗ ∗ 0 ∗ ∗ ⋱ ∗ ∗ 0 ∗ ∗ ∗ ∗ 0 ) {\displaystyle {\begin{pmatrix}0&\ast &&\ast &\ast \\\ast &0&&\ast &\ast \\&&\ddots \\\ast &\ast &&0&\ast \\\ast &\ast &&\ast &0\end{pmatrix}}} is a hollow matrix, where the symbol ∗ {\displaystyle \ast } denotes an arbitrary entry. For example, ( 0 2 6 1 3 4 2 0 4 8 0 9 4 0 2 933 1 4 4 0 6 7 9 23 8 0 ) {\displaystyle {\begin{pmatrix}0&2&6&{\frac {1}{3}}&4\\2&0&4&8&0\\9&4&0&2&933\\1&4&4&0&6\\7&9&23&8&0\end{pmatrix}}} is a hollow matrix.
Deep learning accelerator The blooming DLPs Deep_learning_accelerator > History > The blooming DLPs Inspired from the pioneer work of DianNao Family, many DLPs are proposed in both academia and industry with design optimized to leverage the features of deep neural networks for high efficiency. Only at ISCA 2016, three sessions, 15% (!) of the accepted papers, are all architecture designs about deep learning. Such efforts include Eyeriss (MIT), EIE (Stanford), Minerva (Harvard), Stripes (University of Toronto) in academia, and TPU (Google), MLU (Cambricon) in industry. We listed several representative works in Table 1.
Stack register Stack registers in x86 Stack_pointer > Stack registers in x86 The new value of SP becomes 0xF81E. The CPU then copies the value of AX to the memory word whose physical address is 0x1F81E. When "PUSH BX" is executed, SP is set to 0xF81C and BX is copied to 0x1F81C.This illustrates how PUSH works.
Query expansion Query expansion methods Query_expansion > Query expansion methods The local analysis refers to the relevance feedback introduced by Rocchio. Rocchio proposed to judge manually some of the retrieved documents and use this feedback information to expand the query. Since collecting users' judgment can be challenging, only the first top retrieved documents are considered as relevant.
Electron diffraction Further developments Electron_diffraction > History > Further developments Averaging over different directions has, empirically, been found to significantly reduce dynamical diffraction effects, e.g. See PED history for further details. Not only is it easier to identify known structures with this approach, it can also be used to solve unknown structures in some cases – see precession electron diffraction for further information.The development of experimental methods exploiting ultra-high vacuum technologies (e.g. the approach described by Alpert in 1953) to better control surfaces, making low-energy electron diffraction and reflection high-energy electron diffraction more reliable and reproducible techniques. In the early days the surfaces were not well controlled; with these technologies they can both be cleaned and remain clean for hours to days, a key component of surface science.
Dynamic mutation Summary Dynamic_mutation Generally the larger the expansion the more likely they are to cause disease or increase the severity of disease. This property results in the characteristic of anticipation seen in trinucleotide repeat disorders. Anticipation describes the tendency of age of onset to decrease and severity of symptoms to increase through successive generations of an affected family due to the expansion of these repeats.
Optical aberrations Overview Aberration_(optics) > Overview With an ideal lens, light from any given point on an object would pass through the lens and come together at a single point in the image plane (or, more generally, the image surface). Real lenses do not focus light exactly to a single point, however, even when they are perfectly made. These deviations from the idealized lens performance are called aberrations of the lens. Aberrations fall into two classes: monochromatic and chromatic.
Winogradsky column Construction Winogradsky_column > Construction Alternatively, some procedures call for sand to be used for the layer above the enriched sediment as to allow for easier observation and sampling of resulting populations. This is followed by water from the pond to saturate the mud (or sand) and occupy half the remaining volume. The column is sealed tightly to prevent evaporation of water and incubated for several months in strong natural light.
Broadcast signal Social impact Broadcast_video > Social impact Television and radio programs are distributed through radio broadcasting or cable, often both simultaneously. By coding signals and having a cable converter box with decoding equipment in homes, the latter also enables subscription-based channels, pay-tv and pay-per-view services. In his essay, John Durham Peters wrote that communication is a tool used for dissemination.
Topological phase transitions Topological order Topological_phase_transition > References by categories > Topological order Int. J. Mod. Phys.
Atomicity, consistency, isolation, durability Locking vs. multiversioning Atomicity,_consistency,_isolation,_durability > Implementation > Locking vs. multiversioning For example, if user A is running a transaction that has to read a row of data that user B wants to modify, user B must wait until user A's transaction completes. Two-phase locking is often applied to guarantee full isolation. An alternative to locking is multiversion concurrency control, in which the database provides each reading transaction the prior, unmodified version of data that is being modified by another active transaction.
Electrical contact Electrical contact theory Electrical_contacts > Electrical contact theory Ragnar Holm contributed greatly to electrical contact theory and application.Macroscopically smooth and clean surfaces are microscopically rough and, in air, contaminated with oxides, adsorbed water vapor, and atmospheric contaminants. When two metal electrical contacts touch, the actual metal-to-metal contact area is small compared to the total contact-to-contact area physically touching. In electrical contact theory, the relatively small area where electrical current flows between two contacts is called the a-spot where "a" stands for asperity. If the small a-spot is treated as a circular area and the resistivity of the metal is homogeneous, then the current and voltage in the metal conductor has spherical symmetry and a simple calculation can relate the size of the a-spot to the resistance of the electrical contact interface.
Economic policy Evidence-based policy Economic_policy > Economic policy through history > Evidence-based policy However, the emphasis put on experimental evidence by the movement of evidence-based policy (and evidence-based medicine) results from the narrowly construed notion of intervention, which encompasses only policy decisions concerned with policymaking aimed at modifying causes to influence effects. In contrast to this idealized view of evidence-based policy movement, economic policymaking is a broader term that includes also institutional reforms and actions that do not require causal claims to be neutral under interventions. Such policy decisions can be grounded in, respectively, mechanistic evidence and correlational (econometric) studies.
Maintenance theories of aging Progeria Aging_theories_based_on_group_selection > Diseases > Progeroid syndromes > Progeria Those who have HGPS are prone to suffer from neurological and cardiovascular disorders. HGPS is caused by a point mutation in the gene that encodes lamin A protein. Lamin A promotes genetic stability by maintaining levels of proteins that have key roles in non-homologous end joining and homologous recombination. Mouse cells deficient for maturation of prelamin A show increased DNA damage and chromosome aberrations and have increased sensitivity to DNA damaging agents. In HGPS, the inability to adequately repair DNA damages due to defective A-type lamin may cause aspects of laminopathy-based premature aging.
Horner–Wadsworth–Emmons reaction Reaction mechanism Horner–Wadsworth–Emmons_reaction > Reaction mechanism The Horner–Wadsworth–Emmons reaction begins with the deprotonation of the phosphonate to give the phosphonate carbanion 1. Nucleophilic addition of the carbanion onto the aldehyde 2 (or ketone) producing 3a or 3b is the rate-limiting step. If R2 = H, then intermediates 3a and 4a and intermediates 3b and 4b can interconvert with each other.
Hypertext Transfer Protocol over Secure Socket Layer In case of compromised secret (private) key HTTP_Secure > Technical > Server setup > In case of compromised secret (private) key An important property in this context is perfect forward secrecy (PFS). Possessing one of the long-term asymmetric secret keys used to establish an HTTPS session should not make it easier to derive the short-term session key to then decrypt the conversation, even at a later time. Diffie–Hellman key exchange (DHE) and Elliptic curve Diffie–Hellman key exchange (ECDHE) are in 2013 the only schemes known to have that property. In 2013, only 30% of Firefox, Opera, and Chromium Browser sessions used it, and nearly 0% of Apple's Safari and Microsoft Internet Explorer sessions.
Granular layer (cerebellum) Deep nuclei Cerebellar_cortex > Structure > Microanatomy > Deep nuclei (The globose and the emboliform nuclei are also referred to as combined in the interposed nucleus). The fastigial and interposed nuclei belong to the spinocerebellum. The dentate nucleus, which in mammals is much larger than the others, is formed as a thin, convoluted layer of gray matter, and communicates exclusively with the lateral parts of the cerebellar cortex.
Chaotic mixing Fluid flows Chaotic_mixing > Context of chaotic advection > Fluid flows Two basic mechanisms are responsible for fluid mixing: diffusion and advection. In liquids, molecular diffusion alone is hardly efficient for mixing. Advection, that is the transport of matter by a flow, is required for better mixing.
Self-adjoint operators A simple example Self-adjoint_operators > Symmetric operators > A simple example As noted above, the spectral theorem applies only to self-adjoint operators, and not in general to symmetric operators. Nevertheless, we can at this point give a simple example of a symmetric operator that has an orthonormal basis of eigenvectors. (This operator is actually "essentially self-adjoint.")
Minsk family of computers Models Minsk_family_of_computers > Models It supported COBOL, FORTRAN and ALGAMS (a version of ALGOL). This and earlier versions also used a machine-oriented language called AKI (AvtoKod "Inzhener", i.e., "Engineer's Autocode"). It stood somewhere between the native assembly language SSK (Sistema Simvolicheskogo Kodirovaniya, or "System of symbolic coding") and higher-level languages, like FORTRAN. The word size was 31 bits for Minsk-1 and 37 bits for the other models. At one point the Minsk-222 (an upgraded prototype based on the most popular model, Minsk-22) and Minsk-32 were considered as a potential base for a future unified line of mutually compatible mainframes — that would later become the ES EVM line, but despite being popular among users, good match between their tech and Soviet tech base and familiarity to both programmers and technicians lost to the proposal to copy the IBM/360 line of mainframes — the possibility to just copy all the software existing for it was deemed more important.
Condensing coil Spiral Heat_exchangers > Spiral This attribute is often leveraged and partially reallocated to gain other improvements in performance, according to well known tradeoffs in heat exchanger design. (A notable tradeoff is capital cost vs operating cost.) A compact SHE may be used to have a smaller footprint and thus lower all-around capital costs, or an oversized SHE may be used to have less pressure drop, less pumping energy, higher thermal efficiency, and lower energy costs.
Mathematical theorem Informal account of theorems Mathematical_theorem > Informal account of theorems These hypotheses form the foundational basis of the theory and are called axioms or postulates. The field of mathematics known as proof theory studies formal languages, axioms and the structure of proofs. Some theorems are "trivial", in the sense that they follow from definitions, axioms, and other theorems in obvious ways and do not contain any surprising insights.
Cleavage-stage embryo Mammals Cleavage-stage_embryo > Mammals Mammals have a slow rate of division that is between 12 and 24 hours. These cellular divisions are asynchronous. Zygotic transcription starts at the two-, four-, or eight-cell stage.
REST API Summary RESTful_API REST (Representational state transfer) is a software architectural style that was created to guide the design and development of the architecture for the World Wide Web. REST defines a set of constraints for how the architecture of an Internet-scale distributed hypermedia system, such as the Web, should behave. The REST architectural style emphasises the scalability of interactions between components, uniform interfaces, independent deployment of components, and the creation of a layered architecture to facilitate caching of components to reduce user-perceived latency, enforce security, and encapsulate legacy systems.REST has been employed throughout the software industry to create stateless, reliable Web-based applications. An application that obeys the REST constraints may be informally described as RESTful, although this term is more commonly associated with the design of HTTP-based APIs and what are widely considered best practices regarding the "verbs" (HTTP methods) a resource responds to while having little to do with REST as originally formulated—and is often even at odds with the concept.
Algorithmic probability II. Levin's Universal Distribution Algorithmic_probability > Fundamental Theorems > II. Levin's Universal Distribution Given that any uniquely-decodable code satisfies the Kraft-McMillan inequality, prefix-free Kolmogorov Complexity allows us to derive the Universal Distribution: P ( x ) = ∑ U ∘ P = x P ( U ∘ p = x ) = ∑ U ∘ p = x 2 − K U ( p ) ≤ 1 {\displaystyle P(x)=\sum _{U\circ P=x}P(U\circ p=x)=\sum _{U\circ p=x}2^{-K_{U}(p)}\leq 1} where the fact that U {\displaystyle U} may simulate a prefix-free UTM implies that for two distinct descriptions p {\displaystyle p} and p ′ {\displaystyle p'} , p {\displaystyle p} isn't a substring of p ′ {\displaystyle p'} and p ′ {\displaystyle p'} isn't a substring of p {\displaystyle p} .
General Theory of Relativity Relativistic generalization Observer_(relativity) > From classical mechanics to general relativity > Relativistic generalization At small scales, all reference frames that are in free fall are equivalent, and approximately Minkowskian. Consequently, we are now dealing with a curved generalization of Minkowski space. The metric tensor that defines the geometry—in particular, how lengths and angles are measured—is not the Minkowski metric of special relativity, it is a generalization known as a semi- or pseudo-Riemannian metric. Furthermore, each Riemannian metric is naturally associated with one particular kind of connection, the Levi-Civita connection, and this is, in fact, the connection that satisfies the equivalence principle and makes space locally Minkowskian (that is, in suitable locally inertial coordinates, the metric is Minkowskian, and its first partial derivatives and the connection coefficients vanish).
Endocrine glands Disease Ductless_gland > Clinical significance > Disease Hyperparathyroidism results in hypercalcemia and its effects and in extreme bone wasting. Hypoparathyroidism leads to hypocalcemia, evidenced by tetany seizure and respiratory paralysis. Hyposecretion of insulin results in diabetes mellitus; cardinal signs are polyuria, polydipsia, and polyphagia. == References ==
Molecular structure of Nucleic Acids Collaborators and controversy Molecular_Structure_of_Nucleic_Acids:_A_Structure_for_Deoxyribose_Nucleic_Acid > Collaborators and controversy Although Watson and Crick were first to put together all the scattered fragments of information that were required to produce a successful molecular model of DNA, their findings had been based on data collected by researchers in several other laboratories. For example, they drew on published research relating to the discovery of Hydrogen bonds in DNA by John Masson Gulland, Denis Jordan and their colleagues at University College Nottingham in 1947. However the discovery of the DNA double helix also used a considerable amount of material from the unpublished work of Rosalind Franklin, A.R.
173 (number) In mathematics 173_(number) > In mathematics an inconsummate number. the sum of 2 squares: 22 + 132. the sum of three consecutive prime numbers: 53 + 59 + 61. Palindromic number in bases 3 (201023) and 9 (2129).
Simultaneous multithreading Taxonomy Simultaneous_multithreading > Taxonomy Chip-level multiprocessing (CMP or multicore): integrates two or more processors into one chip, each executing threads independently. Any combination of multithreaded/SMT/CMP.The key factor to distinguish them is to look at how many instructions the processor can issue in one cycle and how many threads from which the instructions come. For example, Sun Microsystems' UltraSPARC T1 is a multicore processor combined with fine-grain multithreading technique instead of simultaneous multithreading because each core can only issue one instruction at a time.
Monomial symmetric polynomial Summary Symmetric_polynomial Indeed, a theorem called the fundamental theorem of symmetric polynomials states that any symmetric polynomial can be expressed in terms of elementary symmetric polynomials. This implies that every symmetric polynomial expression in the roots of a monic polynomial can alternatively be given as a polynomial expression in the coefficients of the polynomial.
Heteroclinic channels Control theory Heteroclinic_channels > Concepts > Control theory Control theory, in robotics, deals with the use of dynamical systems to control robotic systems. The goal of robotic control is to perform precise, coordinated actions using physical actuators in response to sensor input. Dynamical systems can be used to drive the robot to a desired state (or set of states) using sensor input to minimize actuator errors.
List of dualities Physics List_of_dualities > Physics Complementarity (physics) Dual resonance model Duality (electricity and magnetism) Englert–Greenberger duality relation Holographic duality Kramers–Wannier duality Mirror symmetry 3D mirror symmetry Montonen–Olive duality Mysterious duality (M-theory) Seiberg duality String duality S-duality T-duality U-duality Wave-particle duality
Raw moments Standardized moments Moment_(mathematics) > Significance of the moments > Standardized moments The normalised n-th central moment or standardised moment is the n-th central moment divided by σn; the normalised n-th central moment of the random variable X is These normalised central moments are dimensionless quantities, which represent the distribution independently of any linear change of scale. For an electric signal, the first moment is its DC level, and the second moment is proportional to its average power.
Decentralized information technology Information technology Decentralization > Technological decentralization > Information technology Decentralization is particularly applicable to business or management units which have a high level of independence, complicated products and customers, and technology less relevant to other units.Information technology applied to government communications with citizens, often called e-Government, is supposed to support decentralization and democratization. Various forms have been instituted in most nations worldwide.The internet is an example of an extremely decentralized network, having no owners at all (although some have argued that this is less the case in recent years). "No one is in charge of internet, and everyone is."
EmDrive Electromagnetic interactions EmDrive > Experimental errors > Electromagnetic interactions These experiments used relatively large electromagnetic inputs to generate small amounts of thrust. As a result, electromagnetic interactions between power leads, between power lines and ambient magnetic fields, or between the apparatus and walls of a test chamber, could all have significant effects. Yang reported in 2016 that an interaction with the Earth's magnetic field had caused the fairly large apparent thrust in their 2012 paper. Tajmar looked for potential Lorentz force interactions between power leads in trying to replicate White's experimental setup.
Polydimethylsiloxane Mechanical properties Dimethyl_polysiloxane > Mechanical properties When the load itself is removed, the strain is slowly recovered (rather than instantaneously). This time-dependent elastic deformation results from the long-chains of the polymer. But the process that is described above is only relevant when cross-linking is present; when it is not, the polymer PDMS cannot shift back to the original state even when the load is removed, resulting in a permanent deformation.
History of the periodic table Mendeleev's predictions and inability to incorporate the rare-earth metals History_of_the_periodic_table > Priority dispute and recognition > Mendeleev's predictions and inability to incorporate the rare-earth metals However, the higher valency for didymium had not been established, and Mendeleev tried to do so himself. Having had no success in that, he abandoned his attempts to incorporate the rare-earth metals in late 1871 and embarked on his grand idea of luminiferous ether. His idea was carried on by Austrian-Hungarian chemist Bohuslav Brauner, who sought to find a place in the periodic table for the rare-earth metals; Mendeleev later referred to him as to "one of the true consolidators of the periodic law".In addition to the predictions of scandium, gallium, and germanium that were quickly realized, Mendeleev's 1871 table left many more spaces for undiscovered elements, though he did not provide detailed predictions of their properties. In total, he predicted eighteen elements, though only half corresponded to elements that were later discovered.
Isogenic human disease models Historical models Isogenic_human_disease_models > Historical models Human isogenic disease models have been likened to 'patients in a test-tube', since they incorporate the latest research into human genetic diseases and do so without the difficulties and limitations involved in using non-human models.Historically, cells obtained from animals, typically mice, have been used to model cancer-related pathways. However, there are obvious limitations inherent in using animals for modelling genetically determined diseases in humans. Despite a large proportion of genetic conservation between humans and mice, there are significant differences between the biology of mice and humans that are important to cancer research. For example, major differences in telomere regulation enable murine cells to bypass the requirement for telomerase upregulation, which is a rate-limiting step in human cancer formation.
Glycoprotein 130 Characteristics Common_gp130_subunit > Characteristics This complex of 3 proteins then homodimerizes to form a hexameric complex which can produce downstream signals. There are many other proteins which associate with gp130, such as cardiotrophin 1 (CT-1), leukemia inhibitory factor (LIF), ciliary neurotrophic factor (CNTF), oncostatin M (OSM), and IL-11. There are also several other proteins which have structural similarity to gp130 and contain the WSXWS motif and preserved cysteine residues. Members of this group include LIF-R, OSM-R, and G-CSF-R.
Multisystem inflammatory syndrome in children Mechanism Multisystem_inflammatory_syndrome_in_children > Mechanism Questions regarding the underlying molecular mechanisms that lead to the disorder following exposure to SARS-CoV-2 include identification of: any genetic predisposition factors; any associations with particular viral variant/s; any molecular patterns capable of triggering the autoimmune/autoinflammatory responses. Another key question is whether the molecular mechanisms that trigger autoimmune/autoinflammatory responses in children with PMIS and adults with severe COVID-19 (including the induction of high concentrations of IL-6) are similar or distinct.A potential link with Kawasaki disease is under discussion. It has been noted that a leading hypothesis for the pathogenesis of Kawasaki disease also involves a hyperinflammatory response to viral infection (such as by a novel RNA virus) in some genetically predisposed children, and that SARS-CoV-2 is now "added to the list" of implicated viral triggers. Hopes have been expressed that study of the new condition may help understand the hidden mechanisms behind Kawasaki disease. But current evidence suggest that MIS-C and Kawasaki disease represent two distinct disease entities
Quantum paraelectricity Summary Quantum_paraelectricity Quantum paraelectricity is a type of incipient ferroelectricity where the onset of ferroelectric order is suppressed by quantum fluctuations. From the soft mode theory of ferroelectricity, this occurs when a ferroelectric instability is stabilized by quantum fluctuations. In this case the soft-mode frequency never becomes unstable (Fig. 1a) as opposed to a regular ferroelectric. Experimentally this is associated with an anomalous behaviour of the dielectric susceptibility, for example in SrTiO3.
Fission product Summary Fission_fragment Due to being relatively neutron-rich for their atomic number, many of them quickly undergo beta decay. This releases additional energy in the form of beta particles, antineutrinos, and gamma rays. Thus, fission events normally result in beta and gamma radiation, even though this radiation is not produced directly by the fission event itself.
List of real analysis topics Convergence List_of_real_analysis_topics > General topics > Convergence Pointwise convergence, Uniform convergence Absolute convergence, Conditional convergence Normal convergence Radius of convergence
Shoreline development index Summary Shoreline_development_index The shoreline development index of a lake is the ratio of the length of the lake's shoreline to the circumference of a circle with the same area as the lake. It is given in equation form as D L = L 2 π A {\textstyle D_{L}={\frac {L}{2{\sqrt {\pi A}}}}} , where D L {\textstyle D_{L}} is shoreline development, L {\displaystyle L} is the length of the lake's shoreline, and A {\displaystyle A} is the lake's area. The length and area should be measured in the units (e.g., m and m2, or km and km2). The shoreline development index is D L = 1 {\displaystyle D_{L}=1} for perfectly circular lakes. D L > 1 {\displaystyle D_{L}>1} for lakes with complex shapes.
Matrix approximation History Singular-value_decomposition > History The first proof of the singular value decomposition for rectangular and complex matrices seems to be by Carl Eckart and Gale J. Young in 1936; they saw it as a generalization of the principal axis transformation for Hermitian matrices. In 1907, Erhard Schmidt defined an analog of singular values for integral operators (which are compact, under some weak technical assumptions); it seems he was unaware of the parallel work on singular values of finite matrices. This theory was further developed by Émile Picard in 1910, who is the first to call the numbers σ k {\displaystyle \sigma _{k}} singular values (or in French, valeurs singulières).
Magnetic gear Design Magnetic_gear > Design Magnetic gear systems typically use permanent magnets. They may also use electromagnets for specialized cases including changeable gear ratio. Magnetic gear coupling can be configured in several ways. Parallel input and output axes, similar to spur gears, have magnetic attraction or repulsion between cogs, such as the north pole magnets on the driving gear attracting the south pole magnets of driven gear or north pole cogs on a driving gear tending to center between north pole cogs of the driven gear.
Rafail Krichevskii Selected publications Rafail_Krichevskii > Selected publications with V.K.Trofimov: "The Performance of Universal Encoding." IEEE Trans. Inform. Theory, V.27:2, (1981) 199–207.
Inseparable degree Informal discussion Inseparable_degree > Informal discussion An arbitrary polynomial f with coefficients in some field F is said to have distinct roots or to be square-free if it has deg f roots in some extension field E ⊇ F {\displaystyle E\supseteq F} . For instance, the polynomial g(X) = X 2 − 1 has precisely deg g = 2 roots in the complex plane; namely 1 and −1, and hence does have distinct roots. On the other hand, the polynomial h(X) = (X − 2)2, which is the square of a non-constant polynomial does not have distinct roots, as its degree is two, and 2 is its only root. Every polynomial may be factored in linear factors over an algebraic closure of the field of its coefficients.
The Message in the Bottle "Culture: The Antinomy of the Scientific Method" The_Message_in_the_Bottle > "Culture: The Antinomy of the Scientific Method" Let us consider another reality in front of us, viz., culture. By culture, we mean the activities of human beings which are not primarily physiological or psychological but simply assertory: for example, language, art, religions, myths, science (as an activity) and economics (also as an activity). The question is, why shouldn’t the scientific method be applied to culture also?
SolarMagic Products SolarMagic > Products The original SolarMagic device was a proprietary brand of power optimizer, a device which isolates the output from each PV-module from the rest of the system, preventing loss of performance by a single module from affecting the rest of the array. Because of the electronic characteristics of solar arrays, real-world conditions such as partial/temporary shading and irregular panel performance can lead to disproportionate and excessive losses of power output from the system. In one study, shading over a day of between 8% and 16% of the PV system surface area led to relative array power losses of between 35% and 40%. Despite National Semiconductor advertisement claims that their power optimizer could recoup up to 57%of the power lost as a result of these phenomena, real-world results typically ranged between 1% and 6% of overall system output improvement.
Population differentiation Population genetics Human_genetic_variation > History and geographic distribution > Population genetics 3,000 generations). The rapid expansion of a previously small population has two important effects on the distribution of genetic variation. First, the so-called founder effect occurs when founder populations bring only a subset of the genetic variation from their ancestral population.
Contact mechanics History Frictionless_contact_mechanics > History The works of Bowden and Tabor yielded several theories in contact mechanics of rough surfaces. The contributions of Archard (1957) must also be mentioned in discussion of pioneering works in this field. Archard concluded that, even for rough elastic surfaces, the contact area is approximately proportional to the normal force. Further important insights along these lines were provided by Greenwood and Williamson (1966), Bush (1975), and Persson (2002). The main findings of these works were that the true contact surface in rough materials is generally proportional to the normal force, while the parameters of individual micro-contacts (i.e., pressure, size of the micro-contact) are only weakly dependent upon the load.
Sunspot equilibrium Sunspots and the Indeterminacy School in Macroeconomics Sunspot_equilibrium > Sunspots and the Indeterminacy School in Macroeconomics The Cass Shell example relies on the fact that general equilibrium models often possess multiple equilibria. Cass and Shell construct an example with three equilibria in period 2 and they showed that, if a subset of people cannot trade financial securities in period 1, there exist additional equilibria which are constructed as randomizations across the multiple equilibria of the original model. If, in contrast, everyone is present in period 1, these randomizations are not possible as a consequence of the first welfare theorem of economics (Fundamental theorems of welfare economics).
Discovery and development of beta-blockers Pharmacokinetics Discovery_and_development_of_beta-blockers > Mechanism of action > Pharmacokinetics The β-adrenergic receptor antagonists all have similar therapeutic and pharmacodynamic actions in patients with cardiovascular disorders. They vary greatly in their pharmacokinetic properties, as they demonstrate a high range of values in plasma protein binding, the percent of drug eliminated by metabolism or unchanged in the urine and hepatic extraction ratio. Each of the β-blockers possesses at least one chiral centre and a high degree of enantioselectivity when binding to the β-adrenergic receptor. For those β-blockers containing a single chiral centre, the (-) enantiomer has a much higher affinity in binding to the β-adrenergic receptor than the (+) enantiomer. All β-blockers used systemically are delivered as racemate, except for timolol.
Memory errors Summary Memory_errors Memory gaps and errors refer to the incorrect recall, or complete loss, of information in the memory system for a specific detail and/or event. Memory errors may include remembering events that never occurred, or remembering them differently from the way they actually happened. These errors or gaps can occur due to a number of different reasons, including the emotional involvement in the situation, expectations and environmental changes. As the retention interval between encoding and retrieval of the memory lengthens, there is an increase in both the amount that is forgotten, and the likelihood of a memory error occurring.
Quantum Computation and Quantum Information Summary Quantum_Computation_and_Quantum_Information Quantum Computation and Quantum Information is a textbook about quantum information science written by Michael Nielsen and Isaac Chuang, regarded as a standard text on the subject. It is informally known as "Mike and Ike", after the candies of that name. The book assumes minimal prior experience with quantum mechanics and with computer science, aiming instead to be a self-contained introduction to the relevant features of both.
Hydrobromic acid Summary Hydrobromic_acid Hydrobromic acid is a strong acid formed by dissolving the diatomic molecule hydrogen bromide (HBr) in water. "Constant boiling" hydrobromic acid is an aqueous solution that distills at 124.3 °C (255.7 °F) and contains 47.6% HBr by mass, which is 8.77 mol/L. Hydrobromic acid has a pKa of −9, making it a stronger acid than hydrochloric acid, but not as strong as hydroiodic acid. Hydrobromic acid is one of the strongest mineral acids known.
Sending loudness rating Summary Sending_loudness_rating 20 micro-Pascals is called the Threshold of human hearing, and is equal to 0 dB Sound pressure level (SPL). ITU-T recommendation P.79 has the frequency weighted sensitivity calculations in it for sending loudness rating (SLR) and receive loudness rating (RLR) for telephony. == References ==
Aldosterone antagonists Examples Aldosterone_antagonist > Examples Members of this class in clinical use include: Widespread use Spironolactone — the first and most widely used member of this class Eplerenone — much more selective than spironolactone on target, but somewhat less potent and efficacious Uncommon use (to date) Canrenone and potassium canrenoate — very limited use Finerenone — nonsteroidal and more potent and selective than either eplerenone or spironolactoneSome drugs also have antimineralocorticoid effects secondary to their main mechanism of actions. Examples include progesterone, drospirenone, gestodene, and benidipine.
DNA structure RNA DNA_structure > Secondary structure > RNA A tetraloop is a four-base pairs hairpin RNA structure. There are three common families of tetraloop in ribosomal RNA: UNCG, GNRA, and CUUG (N is one of the four nucleotides and R is a purine). UNCG is the most stable tetraloop.Pseudoknot is a RNA secondary structure first identified in turnip yellow mosaic virus.
Complex projective line Metric Complex_sphere > Metric Conversely, any metric on an oriented surface uniquely determines a complex structure, which depends on the metric only up to conformal equivalence. Complex structures on an oriented surface are therefore in one-to-one correspondence with conformal classes of metrics on that surface. Within a given conformal class, one can use conformal symmetry to find a representative metric with convenient properties.
Jørgen Pedersen Gram Summary Jørgen_Pedersen_Gram Instead of using a series of logarithmic integrals, Gram's function uses logarithm powers and the zeta function of positive integers. It has recently been supplanted by a formula of Ramanujan that uses the Bernoulli numbers directly instead of the zeta function. In control theory, the Gramian or Gram matrix is an important contribution named after him.
Linearity of expectation Expectations under convergence of random variables Mathematical_expectation > Properties > Expectations under convergence of random variables Then, according to the dominated convergence theorem, E ⁡ \| X \| ≤ E ⁡ < ∞ {\displaystyle \operatorname {E} \|X\|\leq \operatorname {E} <\infty } ; lim n E ⁡ = E ⁡ {\displaystyle \lim _{n}\operatorname {E} =\operatorname {E} } lim n E ⁡ \| X n − X \| = 0. {\displaystyle \lim _{n}\operatorname {E} \|X_{n}-X\|=0.} Uniform integrability: In some cases, the equality lim n E ⁡ = E ⁡ {\displaystyle \lim _{n}\operatorname {E} =\operatorname {E} } holds when the sequence { X n } {\displaystyle \{X_{n}\}} is uniformly integrable.
Acid dyes Description Acid_dyes > Description In this context, if an acid is used instead of water, then the hydrogen ion (H+) is more easily able to dissociate in order to react with the aniline dye anion, allowing the dye to dissolve. Animal protein fibers and the synthetic fiber nylon contain many cationic sites that bind anionic dye. The strength (fastness) of this bond reflects the strength of this ionic interaction.
Analyte Summary Analyte An analyte, component (in clinical chemistry), titrand (in titrations), or chemical species is a substance or chemical constituent that is of interest in an analytical procedure. The purest substances are referred to as analytes, such as 24 karat gold, NaCl, water, etc. In reality, no substance has been found to be 100% pure in its quality, so a substance that is found to be most pure (for some metals, 99% after electrolysis) is called an analyte.
Bayesian programming Summary Bayesian_programming Bayesian programming is a formalism and a methodology for having a technique to specify probabilistic models and solve problems when less than the necessary information is available. Edwin T. Jaynes proposed that probability could be considered as an alternative and an extension of logic for rational reasoning with incomplete and uncertain information. In his founding book Probability Theory: The Logic of Science he developed this theory and proposed what he called “the robot,” which was not a physical device, but an inference engine to automate probabilistic reasoning—a kind of Prolog for probability instead of logic.
Electronic components Capacitors Discrete_components > Passive components > Capacitors Capacitors store and release electrical charge. They are used for filtering power supply lines, tuning resonant circuits, and for blocking DC voltages while passing AC signals, among numerous other uses. Capacitor Integrated capacitors MIS capacitor Trench capacitor Fixed capacitors Ceramic capacitor Film capacitor Electrolytic capacitor Aluminum electrolytic capacitor Tantalum electrolytic capacitor Niobium electrolytic capacitor (Columbium capacitor) Polymer capacitor, OS-CON Supercapacitor (Electric double-layer capacitor) Nanoionic supercapacitor Lithium-ion capacitor Mica capacitor Vacuum capacitor Variable capacitor – adjustable capacitance Tuning capacitor – variable capacitor for tuning a radio, oscillator, or tuned circuit Trimmer capacitor – small variable capacitor for seldom or rare adjustments of LC-circuits Vacuum variable capacitor Capacitors for special applications Power capacitor Safety capacitor Filter capacitor Light-emitting capacitor (LEC) Motor capacitor Photoflash capacitor Reservoir capacitor / Bulk capacitor Coupling capacitor Decoupling capacitor / Buffer capacitor Bypass capacitor Pull capacitor / Padding capacitor Backup capacitor Switched capacitor Feedthrough capacitor Capacitor network (array) Varicap diode – AC capacitance varies according to the DC voltage applied
History of the Church–Turing thesis Gandy: "machine computation", discrete, deterministic, and limited to "local causation" by light speed History_of_the_Church–Turing_thesis > Gandy: "machine computation", discrete, deterministic, and limited to "local causation" by light speed But then he restricts his machines even more: "(2) Secondly we suppose that the progress of calculation by a mechanical device may be described in discrete terms, so that the devices considered are, in a loose sense, digital computers. "(3) Lasty we suppose that the device is deterministic: that is, the subsequent behavior of the device is uniquely determined once a complete description of its initial state is given. "He in fact makes an argument for this "Thesis M" that he calls his "Theorem", the most important "Principle" of which is "Principle IV: Principle of local causation": "Now we come to the most important of our principles.
Continuous-flow manufacturing Summary Continuous-flow_manufacturing There is usually some time spent waiting for the process during a queue-time or wait-time. The larger the batch, the longer each unit has to wait for the rest of the batch to be completed, before it can go forward to the next process. This queue-time is waste, Muda, and represents time lost that is not value-added in the eyes of the customer.
Resistance thermometers Function Platinum-resistance_thermometer > Function Resistance thermometers are constructed in a number of forms and offer greater stability, accuracy and repeatability in some cases than thermocouples. While thermocouples use the Seebeck effect to generate a voltage, resistance thermometers use electrical resistance and require a power source to operate. The resistance ideally varies nearly linearly with temperature per the Callendar–Van Dusen equation. The platinum detecting wire needs to be kept free of contamination to remain stable.
Lateral olfactory tract usher substance Function Lateral_olfactory_tract_usher_substance > Function As LOTUS generates a permissive brain environment for neuronal regeneration, it may aid recovery after spinal cord injury. It also has been shown to reduce synapse loss in a mouse model of Alzheimer's disease. == References ==
Contravariant vector Summary Covariant_vector A scalar (also called type-0 or rank-0 tensor) is an object that does not vary with the change in basis. An example of a physical observable that is a scalar is the mass of a particle. The single, scalar value of mass is independent to changes in basis vectors and consequently is called invariant.
Euler Equations (fluid dynamics) Quasilinear form and characteristic equations Euler_Equations_(fluid_dynamics) > Quasilinear form and characteristic equations Expanding the fluxes can be an important part of constructing numerical solvers, for example by exploiting (approximate) solutions to the Riemann problem. In regions where the state vector y varies smoothly, the equations in conservative form can be put in quasilinear form: ∂ y ∂ t + A i ∂ y ∂ r i = 0 . {\displaystyle {\frac {\partial \mathbf {y} }{\partial t}}+\mathbf {A} _{i}{\frac {\partial \mathbf {y} }{\partial r_{i}}}={\mathbf {0} }.} where A i {\displaystyle \mathbf {A} _{i}} are called the flux Jacobians defined as the matrices: A i ( y ) = ∂ f i ( y ) ∂ y .
Von Neumann–Morgenstern utility theorem Implications for the expected utility hypothesis Compound_lottery > Consequences > Implications for the expected utility hypothesis In 1738, Daniel Bernoulli published a treatise in which he posits that rational behavior can be described as maximizing the expectation of a function u, which in particular need not be monetary-valued, thus accounting for risk aversion. This is the expected utility hypothesis. As stated, the hypothesis may appear to be a bold claim. The aim of the expected utility theorem is to provide "modest conditions" (i.e. axioms) describing when the expected utility hypothesis holds, which can be evaluated directly and intuitively: "The axioms should not be too numerous, their system is to be as simple and transparent as possible, and each axiom should have an immediate intuitive meaning by which its appropriateness may be judged directly.
Complexity and Real Computation Summary Complexity_and_Real_Computation Complexity and Real Computation is a book on the computational complexity theory of real computation. It studies algorithms whose inputs and outputs are real numbers, using the Blum–Shub–Smale machine as its model of computation. For instance, this theory is capable of addressing a question posed in 1991 by Roger Penrose in The Emperor's New Mind: "is the Mandelbrot set computable? "The book was written by Lenore Blum, Felipe Cucker, Michael Shub and Stephen Smale, with a foreword by Richard M. Karp, and published by Springer-Verlag in 1998 (doi:10.1007/978-1-4612-0701-6, ISBN 0-387-98281-7).
Part per million Applications Part_per_million > Applications For instance, the expansion coefficient of some brass alloy, α = 18.7 ppm/°C, may be expressed as 18.7 (μm/m)/°C, or as 18.7 (μ in/in)/°C; the numeric value representing a relative proportion does not change with the adoption of a different unit of length. Similarly, a metering pump that injects a trace chemical into the main process line at the proportional flow rate Qp = 12 ppm, is doing so at a rate that may be expressed in a variety of volumetric units, including 125 μL/L, 125 μ gal / gal, 125 cm3/m3, etc. In nuclear magnetic resonance spectroscopy (NMR), chemical shift is usually expressed in ppm. It represents the difference of a measured frequency in parts per million from the reference frequency.
Sentence diagram Summary Sentence_diagram A sentence diagram is a pictorial representation of the grammatical structure of a sentence. The term "sentence diagram" is used more when teaching written language, where sentences are diagrammed. The model shows the relations between words and the nature of sentence structure and can be used as a tool to help recognize which potential sentences are actual sentences.
Energy of activation Activation energy in a 2D potential energy surface Energy_of_activation > Activation energy in a 2D potential energy surface The bluer the surface, the stronger the hydrogen bonds, so blue colors represent minima energy and red colors are maxima. Tungsten’s PES is symmetric, and has a dip at the bridge site, this dip corresponds to the change of color in the center of the depic. The bluer the surface between the energy minima, the lower the energy barriers, and therefore the more easily hydrogen travels along the surfaces.
Public Administration of Spain Causal link Public_Administration_of_Spain > Patrimonial liability regime > Requirements > Causal link The cause-effect relationship seems to be an obvious and simple requirement in the framework of the liability of the Public Administration for damages in its action. However, the causes of harm are often not unique, nor are they clearly related. Throughout history, three different theories have been applied, focused essentially on resolving cases in which there is a concurrence of causes, which by the way, are the most common assumptions.
Extensible Storage Engine Tables Extensible_Storage_Engine > Tables A table is a homogeneous collection of records, where each record has the same set of columns. Each table is identified by a table name, whose scope is local to the database in which the table is contained. The amount of disk space allocated to a table within a database is determined by a parameter given when the table is created with the CreateTable operation. Tables grow automatically in response to data creation.
Chronic obstructive lung disease Occupational health Chronic_lower_respiratory_disease > Prevention > Occupational health A number of measures have been taken to reduce the likelihood that workers in at-risk industries—such as coal mining, construction and stonemasonry—will develop COPD. Examples of these measures include the creation of public policy, education of workers and management about the risks, promoting smoking cessation, checking workers for early signs of COPD, use of respirators and dust control. Effective dust control can be achieved by improving ventilation, using water sprays and by using mining techniques that minimize dust generation. If a worker develops COPD, further lung damage can be reduced by avoiding ongoing dust exposure, for example by changing their work role.
Natural Selection Directionality of selection Evolutionary_selection > Genetic basis > Directionality of selection Disruptive (or diversifying) selection is selection favoring extreme trait values over intermediate trait values. Disruptive selection may cause sympatric speciation through niche partitioning. Some forms of balancing selection do not result in fixation, but maintain an allele at intermediate frequencies in a population.
Theta vacuum Theta vacua Theta_vacuum > Yang–Mills vacuum > Theta vacua Topological vacua are not candidate vacuum states of Yang–Mills theories since they are not eigenstates of large gauge transformations and so aren't gauge invariant. Instead acting on the state \| n ⟩ {\displaystyle \|n\rangle } with a large gauge transformation Ω m {\displaystyle \Omega _{m}} with winding number m {\displaystyle m} will map it to a different topological vacuum Ω m \| n ⟩ = \| n + m ⟩ {\displaystyle \Omega _{m}\|n\rangle =\|n+m\rangle } . The true vacuum has to be an eigenstate of both small and large gauge transformations. Similarly to the form that eigenstates take in periodic potentials according to Bloch's theorem, the vacuum state is a coherent sum of topological vacua \| θ ⟩ = ∑ n e i n θ \| n ⟩ .
C program Pointers C_programming_language > Data types > Pointers Dereferencing a null pointer value is undefined, often resulting in a segmentation fault. Null pointer values are useful for indicating special cases such as no "next" pointer in the final node of a linked list, or as an error indication from functions returning pointers. In appropriate contexts in source code, such as for assigning to a pointer variable, a null pointer constant can be written as 0, with or without explicit casting to a pointer type, as the NULL macro defined by several standard headers or, since C23 with the constant nullptr.
Neurogenetics Neurological disorders Neurogenetics > Neurological disorders Neurodegenerative diseases are a more common subset of neurological disorders, with examples being Alzheimer's disease and Parkinson's disease. Currently no viable treatments exist that actually reverse the progression of neurodegenerative diseases; however, neurogenetics is emerging as one field that might yield a causative connection. The discovery of linkages could then lead to therapeutic drugs, which could reverse brain degeneration.
Parallel breadth-first search Data structure Parallel_breadth-first_search > Parallel BFS with distributed memory > Implementation optimization strategies > Data structure There are some special data structures that parallel BFS can benefit from, such as CSR (Compressed Sparse Row), bag-structure, bitmap and so on. In the CSR, all adjacencies of a vertex is sorted and compactly stored in a contiguous chunk of memory, with adjacency of vertex i+1 next to the adjacency of i. In the example on the left, there are two arrays, C and R. Array C stores the adjacency lists of all nodes. Array R stored the index in C, the entry R points to the beginning index of adjacency lists of vertex i in array C. The CSR is extremely fast because it costs only constant time to access vertex adjacency. But it is only space-efficient for 1D partitioning.
Mechanics Relativistic Mechanics > Sub-disciplines > Relativistic Akin to the distinction between quantum and classical mechanics, Albert Einstein's general and special theories of relativity have expanded the scope of Newton and Galileo's formulation of mechanics. The differences between relativistic and Newtonian mechanics become significant and even dominant as the velocity of a body approaches the speed of light. For instance, in Newtonian mechanics, the kinetic energy of a free particle is E = 1/2mv2, whereas in relativistic mechanics, it is E = (γ − 1)mc2 (where γ is the Lorentz factor; this formula reduces to the Newtonian expression in the low energy limit).For high-energy processes, quantum mechanics must be adjusted to account for special relativity; this has led to the development of quantum field theory.
Useable Introduction Useable > Introduction The primary notion of usability is that an object designed with a generalized users' psychology and physiology in mind is, for example: More efficient to use—takes less time to accomplish a particular task Easier to learn—operation can be learned by observing the object More satisfying to useComplex computer systems find their way into everyday life, and at the same time the market is saturated with competing brands. This has made usability more popular and widely recognized in recent years, as companies see the benefits of researching and developing their products with user-oriented methods instead of technology-oriented methods. By understanding and researching the interaction between product and user, the usability expert can also provide insight that is unattainable by traditional company-oriented market research. For example, after observing and interviewing users, the usability expert may identify needed functionality or design flaws that were not anticipated.
Lexical preprocessor General purpose preprocessor Lexical_preprocessor > General purpose preprocessor using C preprocessor for devicetree processing within the Linux kernel. using M4 (see on-article example) or C preprocessor as a template engine, to HTML generation. imake, a make interface using the C preprocessor, written for the X Window System but now deprecated in favour of automake. grompp, a preprocessor for simulation input files for GROMACS (a fast, free, open-source code for some problems in computational chemistry) which calls the system C preprocessor (or other preprocessor as determined by the simulation input file) to parse the topology, using mostly the #define and #include mechanisms to determine the effective topology at grompp run time.
Nucleic acids Summary Nucleic_Acid Nucleic acids are chemical compounds that are found in nature. They carry information in cells and make up genetic material. These acids are very common in all living things, where they create, encode, and store information in every living cell of every life-form on Earth.
Electrodynamic tether Tether current Electrodynamic_tether > Tethers as generators > Tether current The amount of current (I) flowing through a tether depends on various factors. One of these is the circuit's total resistance (R). The circuit's resistance consist of three components: the effective resistance of the plasma, the resistance of the tether, and a control variable resistor.In addition, a parasitic load is needed. The load on the current may take the form of a charging device which, in turn, charges reserve power sources such as batteries.
State-transition equation Summary State-transition_equation Solving for X ( s ) {\displaystyle X(s)} gives X ( s ) = ( s I − A ) − 1 x ( 0 ) + ( s I − A ) − 1 . {\displaystyle X(s)=(sI-A)^{-1}x(0)+(sI-A)^{-1}.} So, the state-transition equation can be obtained by taking inverse Laplace transform as x ( t ) = L − 1 x ( 0 ) + L − 1 ( s I − A ) − 1 = ϕ ( t ) x ( 0 ) + ∫ 0 t ϕ ( t − τ ) d t .
Classification of railway accidents Drivers' errors Classification_of_railway_accidents > Classification of rail accidents by causes > Drivers' errors Passing signals at danger Excessive speed Mishandling of the engine (e.g. boiler explosions) Failure to check brakes and safety systems as well as sand reserve Failure to stop at required positions, e.g. level crossings with defective equipment or shunting movements that lead to occupied tracks.
Crossing (physics) Overview Crossing_symmetry > Overview Consider any process involving an incoming particle with momentum p. For the particle to give a measurable contribution to the amplitude, it has to interact with a number of different particles with momenta q 1 , q 2 , . . .

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