Split (1)

train · 253k rows

page_content stringlengths 51 3.15k
Turing machine examples Turing's very first example Turing_machine_examples > Turing's very first example For example, suppose his tape was not initially blank. What would happen? The Turing machine would read different values than the intended values.
Structure constant Summary Structure_constants Given the structure constants, the resulting product is obtained by bilinearity and can be uniquely extended to all vectors in the vector space, thus uniquely determining the product for the algebra. Structure constants are used whenever an explicit form for the algebra must be given. Thus, they are frequently used when discussing Lie algebras in physics, as the basis vectors indicate specific directions in physical space, or correspond to specific particles (recall that Lie algebras are algebras over a field, with the bilinear product being given by the Lie bracket, usually defined via the commutator).
Ostrich meat System overview Struthio_camelus > Physiology > Osmoregulation > System overview The coprodeum and cloaca are the main osmoregulatory mechanisms used for the regulation and reabsorption of ions and water, or net water conservation. As expected in a species inhabiting arid regions, dehydration causes a reduction in fecal water, or dry feces.
Magnetometer (Juno) Summary Magnetometer_(Juno) Magnetometer (MAG) is an instrument suite on the Juno orbiter for planet Jupiter. The MAG instrument includes both the Fluxgate Magnetometer (FGM) and Advanced Stellar Compass (ASC) instruments. There two sets of MAG instrument suites, and they are both positioned on the far end of three solar panel array booms. Each MAG instrument suite observes the same swath of Jupiter, and by having two sets of instruments, determining what signal is from the planet and what is from spacecraft is supported.
Autoimmune hemolytic anemia Summary Autoimmune_haemolytic_anemia Autoimmune hemolytic anemia (AIHA) occurs when antibodies directed against the person's own red blood cells (RBCs) cause them to burst (lyse), leading to an insufficient number of oxygen-carrying red blood cells in the circulation. The lifetime of the RBCs is reduced from the normal 100–120 days to just a few days in serious cases. The intracellular components of the RBCs are released into the circulating blood and into tissues, leading to some of the characteristic symptoms of this condition. The antibodies are usually directed against high-incidence antigens, therefore they also commonly act on allogenic RBCs (RBCs originating from outside the person themselves, e.g. in the case of a blood transfusion).
Liddle's syndrome Cause Liddle's_syndrome > Cause Specifically, the PY motif in the protein is deleted or altered so the E3 ligase (Nedd4) no longer recognizes the channel. This loss of ability to be degraded leads to high amounts of the channel being chronically present on the apical membrane of the epithelial cells that line the collecting ducts of the kidney. This results in a hyperaldosteronism-like state, since aldosterone is typically responsible for creating and inserting these channels. The increased sodium resorption leads to increased resorption of water, and hypertension due to an increase in extracellular volume.
D electron count Possible d electron counts D_electron_count > Possible d electron counts There are many examples of every possible d electron configuration. What follows is a short description of common geometries and characteristics of each possible d electron count and representative examples. d0 Commonly tetrahedral; however it is possible for d0 complexes to accommodate many electron pairs (bonds/coordination number) since their d orbitals are empty and well away from the 18-electron ceiling. Often colorless due to the lack of d to d transitions.
Neuroactive steroids Function Neuroactive_steroid > Function Some major known biological functions of neurosteroids include modulation of neural plasticity, learning and memory processes, behavior, and seizure susceptibility, as well as responses to stress, anxiety, and depression. Neurosteroids also appear to play an important role in various sexually-dimorphic behaviors and emotional responses.Acute stress elevates the levels of inhibitory neurosteroids like allopregnanolone, and these neurosteroids are known to counteract many of the effects of stress. This is similar to the case of endorphins, which are released in response to stress and physical pain and counteract the negative subjective effects of such states. As such, it has been suggested that one of the biological functions of these neuromodulators may be to help maintain emotional homeostasis.
Adaptive immunity Passive memory Acquired_resistance > Immunological memory > Passive memory Passive memory is usually short-term, lasting between a few days and several months. Newborn infants have had no prior exposure to microbes and are particularly vulnerable to infection. Several layers of passive protection are provided by the mother.
Transition metal complexes of 2,2'-bipyridine Summary Transition_metal_complexes_of_2,2'-bipyridine Transition metal complexes of 2,2'-bipyridine are coordination complexes containing one or more 2,2'-bipyridine ligands. Complexes have been described for all of the transition metals. Although few have any practical value, these complexes have been influential.
Mental processing Artificial intelligence Mental_content > Non-human > Artificial intelligence In 1950 Alan M. Turing published "Computing machinery and intelligence" in Mind, in which he proposed that machines could be tested for intelligence using questions and answers. This process is now named the Turing Test. The term Artificial Intelligence (AI) was first used by John McCarthy who considered it to mean "the science and engineering of making intelligent machines". It can also refer to intelligence as exhibited by an artificial (man-made, non-natural, manufactured) entity.
Disequilibrium (thermodynamics) Basic concepts Non-equilibrium_thermodynamics > Basic concepts There are many examples of stationary non-equilibrium systems, some very simple, like a system confined between two thermostats at different temperatures or the ordinary Couette flow, a fluid enclosed between two flat walls moving in opposite directions and defining non-equilibrium conditions at the walls. Laser action is also a non-equilibrium process, but it depends on departure from local thermodynamic equilibrium and is thus beyond the scope of classical irreversible thermodynamics; here a strong temperature difference is maintained between two molecular degrees of freedom (with molecular laser, vibrational and rotational molecular motion), the requirement for two component 'temperatures' in the one small region of space, precluding local thermodynamic equilibrium, which demands that only one temperature be needed. Damping of acoustic perturbations or shock waves are non-stationary non-equilibrium processes. Driven complex fluids, turbulent systems and glasses are other examples of non-equilibrium systems.
Chemical function Table of common functional groups Chemical_function > Table of common functional groups The following is a list of common functional groups. In the formulas, the symbols R and R' usually denote an attached hydrogen, or a hydrocarbon side chain of any length, but may sometimes refer to any group of atoms.
List of file systems Distributed fault-tolerant file systems List_of_file_systems > Distributed file systems > Distributed fault-tolerant file systems Scality is a distributed fault-tolerant filesystem. Tahoe-LAFS is an open source secure, decentralized, fault-tolerant filesystem utilizing encryption as the basis for a least-authority replicated design. A FAT12 and FAT16 (and FAT32) extension to support automatic file distribution across nodes with extra attributes like local, mirror on update, mirror on close, compound on update, compound on close in IBM 4680 OS and Toshiba 4690 OS. The distribution attributes are stored on a file-by-file basis in special entries in the directory table.
Effects of climate change on plant biodiversity Modern context Effects_of_climate_change_on_plant_biodiversity > Modern context There is significant current interest and research focus on the phenomenon of recent anthropogenic climate changes, or global warming. Focus is on identifying the current impacts of climate change on biodiversity, and predicting these effects into the future. Changing climatic variables relevant to the function and distribution of plants include increasing CO2 concentrations, increasing global temperatures, altered precipitation patterns, and changes in the pattern of 'extreme weather events such as cyclones, fires or storms. Highly variable species distribution has resulted from different models with variable bioclimatic changes.Because individual plants and therefore species can only function physiologically, and successfully complete their life cycles under specific environmental conditions (ideally within a subset of these), changes to climate are likely to have significant impacts on plants from the level of the individual right through to the level of the ecosystem or biome.
Liver insufficiency Liver diseases Liver_dysfunction > Liver diseases Analogous terms such as "drug-induced" or "toxic" liver disease are also used to refer to disorders caused by various drugs. Fatty liver disease (hepatic steatosis) is a reversible condition where large vacuoles of triglyceride fat accumulate in liver cells. Non-alcoholic fatty liver disease is a spectrum of disease associated with obesity and metabolic syndrome.
Fixed point iteration Attracting fixed points Fixed_point_iteration > Attracting fixed points It eventually converges to the Dottie number (about 0.739085133), which is a fixed point. That is where the graph of the cosine function intersects the line y = x {\displaystyle y=x} .Not all fixed points are attracting. For example, 0 is a fixed point of the function f(x) = 2x, but iteration of this function for any value other than zero rapidly diverges.
Kepler-277b Orbit Kepler-277b > Characteristics > Orbit Kepler-277b orbits close to its host star, with one orbit lasting 17.324 days. Its semi-major axis, or average distance from the parent object, is about 0.136 AU. For comparison, the planet Mercury in the Solar System takes 88 days to orbit at a distance of 0.38 AU. At this distance, Kepler-277b is very hot and most likely tidally locked to its host star. It is close to a 2:1 resonance with Kepler-277c, which orbits at an average distance of about 0.209 AU.
Control zone Summary Control_zone They can be observed to be usually rectangular, extending along the axis of the main runway, although irregular shapes may be used where more complex airspace dictates this (see Liverpool and East Midlands). A control area (CTA) is often placed between a CTR and nearby airways to give uninterrupted controlled airspace to airways arrivals and departures. In Germany, control zones are a special type of class D airspace, called D (CTR). The main difference to the regular German class D airspace is, that within a CTR there is a minimum required cloud ceiling of 1500 ft AGL.
International School of Information Management Workshops International_School_of_Information_Management > ISiM events / academic activities > Workshops Workshop on Machine Learning (April 2008): Focusing on introducing the basic techniques of Machine Learning, its major areas of application and providing hands on experience to the participants. Faculty: Prof. Sargur N Srihari (SUNY Buffalo, New York). Workshop on Data Warehousing and Data Mining (October 2008): Faculty: Mr. Surya Patchala (Accenture, Hyderabad), Dr. P. Radha Krishna (Infosys, Hyderabad), Mr. Anoop Nambiar (Infosys, Bangalore).
Salen ligand Synthesis and properties Salen_ligand > Synthesis and properties H2salen may be synthesized by the condensation of ethylenediamine and salicylaldehyde. Complexes of salen with metal cations may be made without isolating it from the reaction mixture. This is possible because the stability constant for the formation of the metal complexes are very high, due to the chelate effect. H2L + Mn+ → ML(n−2)+ + 2 H+where L stands for the ligand.
Renal ultrasonograph Hydronephrosis Renal_ultrasonography > Hydronephrosis One of the primary indications for referral to US evaluation of the kidneys is evaluation of the urinary collecting system. Enlargement of the urinary collecting system is usually related to urinary obstruction and can include the pelvis, the calyces and the ureter. Hydronephrosis is seen as an anechoic fluid-filled interconnected space with enhancement within the renal sinus, and normally, the dilated pelvis can be differentiated from the dilated calyces. Several conditions can result in urinary obstruction.
Isaac Newton Summary Isaac_Newton He demonstrated that the motion of objects on Earth and celestial bodies could be accounted for by the same principles. Newton's inference that the Earth is an oblate spheroid was later confirmed by the geodetic measurements of Maupertuis, La Condamine, and others, convincing most European scientists of the superiority of Newtonian mechanics over earlier systems. Newton built the first practical reflecting telescope and developed a sophisticated theory of colour based on the observation that a prism separates white light into the colours of the visible spectrum.
Fixed point iteration Attracting fixed points Fixed_point_iteration > Attracting fixed points We say that the fixed point of f ( x ) = 2 x {\displaystyle f(x)=2x} is repelling. An attracting fixed point is said to be a stable fixed point if it is also Lyapunov stable. A fixed point is said to be a neutrally stable fixed point if it is Lyapunov stable but not attracting. The center of a linear homogeneous differential equation of the second order is an example of a neutrally stable fixed point. Multiple attracting points can be collected in an attracting fixed set.
Cerebellar vermis Summary Cerebellar_vermis The cerebellar vermis (from Latin vermis, "worm") is located in the medial, cortico-nuclear zone of the cerebellum, which is in the posterior fossa of the cranium. The primary fissure in the vermis curves ventrolaterally to the superior surface of the cerebellum, dividing it into anterior and posterior lobes. Functionally, the vermis is associated with bodily posture and locomotion. The vermis is included within the spinocerebellum and receives somatic sensory input from the head and proximal body parts via ascending spinal pathways.The cerebellum develops in a rostro-caudal manner, with rostral regions in the midline giving rise to the vermis, and caudal regions developing into the cerebellar hemispheres.
Metal carbonyl Infrared spectra Carbonyl_ligand > Analytical characterization > Infrared spectra The number of IR-observable vibrational modes for some metal carbonyls are shown in the table. Exhaustive tabulations are available. These rules apply to metal carbonyls in solution or the gas phase. Low-polarity solvents are ideal for high resolution. For measurements on solid samples of metal carbonyls, the number of bands can increase owing in part to site symmetry.
Johannes Kepler Mysterium Cosmographicum Johannes_Kepler > Astronomy > Mysterium Cosmographicum Mysterium was published late in 1596, and Kepler received his copies and began sending them to prominent astronomers and patrons early in 1597; it was not widely read, but it established Kepler's reputation as a highly skilled astronomer. The effusive dedication, to powerful patrons as well as to the men who controlled his position in Graz, also provided a crucial doorway into the patronage system.In 1621, Kepler published an expanded second edition of Mysterium, half as long again as the first, detailing in footnotes the corrections and improvements he had achieved in the 25 years since its first publication. In terms of impact, the Mysterium can be seen as an important first step in modernizing the theory proposed by Copernicus in his De revolutionibus orbium coelestium. Whilst Copernicus sought to advance a heliocentric system in this book, he resorted to Ptolemaic devices (viz., epicycles and eccentric circles) in order to explain the change in planets' orbital speed, and also continued to use as a point of reference the center of the Earth's orbit rather than that of the Sun "as an aid to calculation and in order not to confuse the reader by diverging too much from Ptolemy." Modern astronomy owes much to Mysterium Cosmographicum, despite flaws in its main thesis, "since it represents the first step in cleansing the Copernican system of the remnants of the Ptolemaic theory still clinging to it."
System development methodology Rapid application development Software_Process > Methodologies > Rapid application development In the next stage, requirements are verified using prototyping, eventually to refine the data and process models. These stages are repeated iteratively; further development results in "a combined business requirements and technical design statement to be used for constructing new systems".The term was first used to describe a software development process introduced by James Martin in 1991. According to Whitten (2003), it is a merger of various structured techniques, especially data-driven information technology engineering, with prototyping techniques to accelerate software systems development.The basic principles of rapid application development are: Key objective is for fast development and delivery of a high-quality system at a relatively low investment cost.
Hole argument Disputing the above version of Einstein's hole argument Hole_argument > Disputing the above version of Einstein's hole argument Einstein's derivation of the gravitational field equations was delayed because of the hole argument which he created in 1913. However the problem was not as given in the section above. By 1912, the time Einstein started what he called his "struggle with the meaning of the coordinates", he already knew to search for tensorial equations as these are unaffected by coordinate change. He had already found the form of the gravitational field (namely as a tetrad or frame field e μ I ( x ) {\displaystyle e_{\mu }^{I}(x)} or metric g μ ν ( x ) {\displaystyle g_{\mu \nu }(x)} ), and the equations of motion of matter in a given gravitational field (which follow from maximizing the proper time given by d s 2 = g μ ν ( x ) d x μ d x ν {\displaystyle ds^{2}=g_{\mu \nu }(x)dx^{\mu }dx^{\nu }} ).
Subformula property Summary Subformula_property Proof theory is a major branch of mathematical logic and theoretical computer science within which proofs are treated as formal mathematical objects, facilitating their analysis by mathematical techniques. Proofs are typically presented as inductively-defined data structures such as lists, boxed lists, or trees, which are constructed according to the axioms and rules of inference of a given logical system. Consequently, proof theory is syntactic in nature, in contrast to model theory, which is semantic in nature. Some of the major areas of proof theory include structural proof theory, ordinal analysis, provability logic, reverse mathematics, proof mining, automated theorem proving, and proof complexity. Much research also focuses on applications in computer science, linguistics, and philosophy.
Admissible rule Decidability and reduced rules Admissible_rule > Decidability and reduced rules The basic question about admissible rules of a given logic is whether the set of all admissible rules is decidable. Note that the problem is nontrivial even if the logic itself (i.e., its set of theorems) is decidable: the definition of admissibility of a rule A/B involves an unbounded universal quantifier over all propositional substitutions. Hence a priori we only know that admissibility of rule in a decidable logic is Π 1 0 {\displaystyle \Pi _{1}^{0}} (i.e., its complement is recursively enumerable). For instance, it is known that admissibility in the bimodal logics Ku and K4u (the extensions of K or K4 with the universal modality) is undecidable.
Context-free languages Closure properties Context_free_language > Properties > Closure properties The class of context-free languages is closed under the following operations. That is, if L and P are context-free languages, the following languages are context-free as well: the union L ∪ P {\displaystyle L\cup P} of L and P the reversal of L the concatenation L ⋅ P {\displaystyle L\cdot P} of L and P the Kleene star L ∗ {\displaystyle L^{*}} of L the image φ ( L ) {\displaystyle \varphi (L)} of L under a homomorphism φ {\displaystyle \varphi } the image φ − 1 ( L ) {\displaystyle \varphi ^{-1}(L)} of L under an inverse homomorphism φ − 1 {\displaystyle \varphi ^{-1}} the circular shift of L (the language { v u: u v ∈ L } {\displaystyle \{vu:uv\in L\}} ) the prefix closure of L (the set of all prefixes of strings from L) the quotient L/R of L by a regular language R
Electrical units Electric current Electric_system > Concepts > Electric current That water could be decomposed by the current from a voltaic pile was discovered by Nicholson and Carlisle in 1800, a process now known as electrolysis. Their work was greatly expanded upon by Michael Faraday in 1833. Current through a resistance causes localised heating, an effect James Prescott Joule studied mathematically in 1840.: 23–24 One of the most important discoveries relating to current was made accidentally by Hans Christian Ørsted in 1820, when, while preparing a lecture, he witnessed the current in a wire disturbing the needle of a magnetic compass.
Symmetry in mathematics Integrating Mathematical_symmetry > Symmetry in calculus > Integrating The integral of an odd function from −A to +A is zero, provided that A is finite and that the function is integrable (e.g., has no vertical asymptotes between −A and A).The integral of an even function from −A to +A is twice the integral from 0 to +A, provided that A is finite and the function is integrable (e.g., has no vertical asymptotes between −A and A). This also holds true when A is infinite, but only if the integral converges.
Deadwood Formation Environment of deposition Deadwood_Formation > Environment of deposition In most areas the sediments of the Deadwood Formation were deposited in near shore, shallow water environments as an ancient sea advanced across the exposed and weathered landscape of Precambrian rocks. Most of the conglomerates appear to be matrix-supported debris flow deposits.
Interpersonal relationship Power and dominance Interpersonal_relationship > Power and dominance A power structure describes power and dominance relationships in a larger society. For example, a feudal society under a monarchy exhibits a strong dominance hierarchy in both economics and physical power, whereas dominance relationships in a society with democracy and capitalism are more complicated. In business relationships, dominance is often associated with economic power.
Adaptive learning Student model Adaptive_learning > Technology and methodology > Student model A large pool of questions is amassed and rated according to difficulty, through expert analysis, experimentation, or a combination of the two. The computer then performs what is essentially a binary search, always giving the subject a question which is halfway between what the computer has already determined to be the subject's maximum and minimum possible skill levels. These levels are then adjusted to the level of the difficulty of the question, reassigning the minimum if the subject answered correctly, and the maximum if the subject answered incorrectly.
Turing degree Monographs and survey articles (graduate level) Recursively_enumerable_Turing_degree > References > Monographs and survey articles (graduate level) ISBN 978-0-444-87295-1. MR 0982269. Odifreddi, Piergiorgio (1999).
Taylor approximation Derivation for the integral form of the remainder Taylor's_Theorem > Proofs > Derivation for the integral form of the remainder Due to absolute continuity of f ( k ) {\displaystyle f^{(k)}} on the closed interval between a {\textstyle a} and x {\textstyle x} its derivative f ( k + 1 ) {\displaystyle f^{(k+1)}} exists as an L 1 {\displaystyle L^{1}} -function, and we can use fundamental theorem of calculus and integration by parts. This same proof applies for the Riemann integral assuming that f ( k ) {\displaystyle f^{(k)}} is continuous on the closed interval and differentiable on the open interval between a {\textstyle a} and x {\textstyle x} , and this leads to the same result than using the mean value theorem. The fundamental theorem of calculus states that Now we can integrate by parts and use the fundamental theorem of calculus again to see that which is exactly Taylor's theorem with remainder in the integral form in the case k = 1 {\displaystyle k=1} .
GPS/INS Applications GPS/INS > Applications GPS/INS is commonly used on aircraft for navigation purposes. Using GPS/INS allows for smoother position and velocity estimates that can be provided at a sampling rate faster than the GPS receiver. This also allows for accurate estimation of the aircraft attitude (roll, pitch, and yaw) angles.
Author-level metric Field-weighted Citation Impact Author-level_metrics > List of metrics > Field-weighted Citation Impact Field-weighted Citation Impact (FWCI) is an author-level metric introduced and applied by Scopus SciVal. FWCI equals to the total citations actually received divided by the total citations that would be expected based on the average of the considered field. FWCI of 1 means that the output performs just as expected for the global average. More than 1 means that the author outperforms the average, and less than 1 means that the author underperforms. For instance, 1.55 {\displaystyle 1.55} means 55 {\displaystyle 55} % more likely to be cited.
Binomial options model Use of the model Binomial_options_pricing_model > Use of the model Although computationally slower than the Black–Scholes formula, it is more accurate, particularly for longer-dated options on securities with dividend payments. For these reasons, various versions of the binomial model are widely used by practitioners in the options markets.For options with several sources of uncertainty (e.g., real options) and for options with complicated features (e.g., Asian options), binomial methods are less practical due to several difficulties, and Monte Carlo option models are commonly used instead. When simulating a small number of time steps Monte Carlo simulation will be more computationally time-consuming than BOPM (cf. Monte Carlo methods in finance).
Glossary of chemistry terms C Glossary_of_chemistry_terms > C conjugate acid conjugate base conjugated system A molecule that contains double or triple bonds separated by one single bond; e.g. the compound buta-1,3-diene, with the chemical structure H2C=CH−CH=CH2, has conjugated double bonds. In such molecules, there is some delocalization of electrons in the pi orbitals between the carbon atoms linked by the single bond. constitutional isomer See structural isomer.
Central tendency Measures Measure_of_central_tendency > Measures Generalized mean A generalization of the Pythagorean means, specified by an exponent. Geometric mean the nth root of the product of the data values, where there are n of these. This measure is valid only for data that are measured absolutely on a strictly positive scale.
Closed circuit rebreather General concept Closed_circuit_breathing_apparatus > General concept As a person breathes, the body consumes oxygen and produces carbon dioxide. Base metabolism requires about 0.25 L/min of oxygen from a breathing rate of about 6 L/min, and a fit person working hard may ventilate at a rate of 95 L/min but will only metabolise about 4 L/min of oxygen The oxygen metabolised is generally about 4% to 5% of the inspired volume at normal atmospheric pressure, or about 20% of the available oxygen in the air at sea level. Exhaled air at sea level contains roughly 13.5% to 16% oxygen.The situation is even more wasteful of oxygen when the oxygen fraction of the breathing gas is higher, and in underwater diving, the compression of breathing gas due to depth makes the recirculation of exhaled gas even more desirable, as an even larger proportion of open circuit gas is wasted. Continued rebreathing of the same gas will deplete the oxygen to a level which will no longer support consciousness, and eventually life, so gas containing oxygen must be added to the breathing gas to maintain the required concentration of oxygen.However, if this is done without removing the carbon dioxide, it will rapidly build up in the recycled gas, resulting almost immediately in mild respiratory distress, and rapidly developing into further stages of hypercapnia, or carbon dioxide toxicity. A high ventilation rate is usually necessary to eliminate the metabolic product carbon dioxide (CO2). The breathing reflex is triggered by CO2 concentration in the blood, not by the oxygen concentration, so even a small buildup of CO2 in the inhaled gas quickly becomes intolerable; if a person tries to directly rebreathe their exhaled breathing gas, they will soon feel an acute sense of suffocation, so rebreathers must remove the CO2 in a component known as a carbon dioxide scrubber.By adding sufficient oxygen to compensate for the metabolic usage, removing the carbon dioxide, and rebreathing the gas, most of the volume is conserved.
Wallerian degeneration Clearance in PNS Wallerian_degeneration > Myelin clearance > Clearance in PNS The recruitment of macrophages helps improve the clearing rate of myelin debris. The resident macrophages present in the nerves release further chemokines and cytokines to attract further macrophages. The degenerating nerve also produce macrophage chemotactic molecules.
Discriminant Conic sections Discriminant_of_a_polynomial > Generalizations > Conic sections {\displaystyle ax^{2}+2bxy+cy^{2}+2dxz+2eyz+fz^{2}=0.} Its discriminant is the determinant \| a b d b c e d e f \| . {\displaystyle {\begin{vmatrix}a&b&d\\b&c&e\\d&e&f\end{vmatrix}}.}
Explorer 61 Spacecraft Explorer_61 > Spacecraft The magnetometers were deployed after launch to a position 6 m (20 ft) behind the spacecraft. At this distance, the influence of magnetic materials from the instrument and base module (chiefly from the star cameras) was less than 1 mT. Sixteen complete vector magnetic field measurements and eight scalar measurements were obtained every second.
Glossary of areas of mathematics A Glossary_of_areas_of_mathematics > A Analytic geometry 1. Also known as Cartesian geometry, the study of Euclidean geometry using Cartesian coordinates. 2.
Lie Group Topological definition Matrix_Lie_group > Definitions and examples > Topological definition A Lie group can be defined as a (Hausdorff) topological group that, near the identity element, looks like a transformation group, with no reference to differentiable manifolds. First, we define an immersely linear Lie group to be a subgroup G of the general linear group GL ⁡ ( n , C ) {\displaystyle \operatorname {GL} (n,\mathbb {C} )} such that for some neighborhood V of the identity element e in G, the topology on V is the subspace topology of GL ⁡ ( n , C ) {\displaystyle \operatorname {GL} (n,\mathbb {C} )} and V is closed in GL ⁡ ( n , C ) {\displaystyle \operatorname {GL} (n,\mathbb {C} )} . G has at most countably many connected components. (For example, a closed subgroup of GL ⁡ ( n , C ) {\displaystyle \operatorname {GL} (n,\mathbb {C} )} ; that is, a matrix Lie group satisfies the above conditions.)
The Variable Summary The_Variable The episode was written by executive producers Edward Kitsis and Adam Horowitz and directed by Paul Edwards. It serves as a companion piece to the season four episode "The Constant", another episode that heavily features the character Daniel, and the third Lost episode to deal directly with the concept of time travel. Since airing, the episode has received generally positive reviews from television critics, mostly complimenting Davies's performance.
Gearbox bicycle Methods Gearbox_bicycle > Methods At least three different gearing techniques have been employed. Epicyclic gears, as in hub gears. Spur gears, as in most automobile transmissions. Derailleur gears, as on many bicycles, but fully enclosed.
Cognitive semantics Points of contrast Cognitive_semantics > Points of contrast Lexical units can be understood as holding meaning either by virtue of set of things they may apply to (called the "extension" of the word), or in terms of the common properties that hold between these things (called its "intension"). The intension provides an interlocutor with the necessary and sufficient conditions that let a thing qualify as a member of some lexical unit's extension. Roughly, propositional functions are those abstract instructions that guide the interpreter in taking the free variables in an open sentence and filling them in, resulting in a correct understanding of the sentence as a whole.
Mountain car problem Introduction Mountain_car_problem > Introduction The mountain car problem, although fairly simple, is commonly applied because it requires a reinforcement learning agent to learn on two continuous variables: position and velocity. For any given state (position and velocity) of the car, the agent is given the possibility of driving left, driving right, or not using the engine at all. In the standard version of the problem, the agent receives a negative reward at every time step when the goal is not reached; the agent has no information about the goal until an initial success.
Upwelling current Other sources Upwelling_current > Types > Coastal > Other sources For example when a tropical cyclone transits an area, usually when moving at speeds of less than 5 mph (8 km/h). The cyclonic winds cause a divergence in the surface water in the Ekman layer, that turn requires upwelling of deeper water to maintain continuity. Artificial upwelling is produced by devices that use ocean wave energy or ocean thermal energy conversion to pump water to the surface. Ocean wind turbines are also known to produce upwellings. Ocean wave devices have been shown to produce plankton blooms.
Electrical engineering Control engineering Electrical_engineering > Subfields > Control engineering It also plays an important role in industrial automation. Control engineers often use feedback when designing control systems. For example, in an automobile with cruise control the vehicle's speed is continuously monitored and fed back to the system which adjusts the motor's power output accordingly. Where there is regular feedback, control theory can be used to determine how the system responds to such feedback. Control engineers also work in robotics to design autonomous systems using control algorithms which interpret sensory feedback to control actuators that move robots such as autonomous vehicles, autonomous drones and others used in a variety of industries.
Adverse reaction to cytokines Summary Recombinant_cytokine Cytokines are produced by a broad range of cells, including immune cells like macrophages, B lymphocytes, T lymphocytes and mast cells, as well as endothelial cells, fibroblasts, and various stromal cells; a given cytokine may be produced by more than one type of cell. They act through cell surface receptors and are especially important in the immune system; cytokines modulate the balance between humoral and cell-based immune responses, and they regulate the maturation, growth, and responsiveness of particular cell populations. Some cytokines enhance or inhibit the action of other cytokines in complex ways.
Pattern recognition receptor TLR signaling Cytoplasmic_PRR > PRR types and signaling > Toll-like receptors (TLR) > TLR signaling The signaling complex reacts with TRAF6 which leads to TAK1 activation and consequently the induction of inflammatory cytokines. The TRIF-dependent pathway is induced by macrophages and DCs after TLR3 and TLR4 stimulation. Molecules released following TLR activation signal to other cells of the immune system making TLRs key elements of innate immunity and adaptive immunity.
Fluid Physics Fluid > Physics Fluids display properties such as: lack of resistance to permanent deformation, resisting only relative rates of deformation in a dissipative, frictional manner, and the ability to flow (also described as the ability to take on the shape of the container).These properties are typically a function of their inability to support a shear stress in static equilibrium. In contrast, solids respond to shear either with a spring-like restoring force, which means that deformations are reversible, or they require a certain initial stress before they deform (see plasticity). Solids respond with restoring forces to both shear stresses and to normal stresses—both compressive and tensile. In contrast, ideal fluids only respond with restoring forces to normal stresses, called pressure: fluids can be subjected to both compressive stress, corresponding to positive pressure, and to tensile stress, corresponding to negative pressure.
Neurological examination Patient's history Neurological_examination > Patient's history The interval of a complaint is important as it can help aid the diagnosis. For example, vascular disorders (such as strokes) occur very frequently over minutes or hours, whereas chronic disorders (such as Alzheimer's disease) occur over a matter of years.Carrying out a 'general' examination is just as important as the neurological exam, as it may lead to clues to the cause of the complaint. This is shown by cases of cerebral metastases where the initial complaint was of a mass in the breast.
Gradient descent Summary Steepest_descent In mathematics, gradient descent (also often called steepest descent) is a first-order iterative optimization algorithm for finding a local minimum of a differentiable function. The idea is to take repeated steps in the opposite direction of the gradient (or approximate gradient) of the function at the current point, because this is the direction of steepest descent. Conversely, stepping in the direction of the gradient will lead to a local maximum of that function; the procedure is then known as gradient ascent. It is particularly useful in machine learning for minimizing the cost or loss function.
Hopf algebra Group-like elements Hopf_algebras > Formal definition > Group-like elements A group-like element is a nonzero element x such that Δ(x) = x⊗x. The group-like elements form a group with inverse given by the antipode. A primitive element x satisfies Δ(x) = x⊗1 + 1⊗x.
Cross-bridge cycle Sliding filament theory Cross-bridge_cycle > Vertebrate > Skeletal muscle > Sliding filament theory The sliding filament theory describes a process used by muscles to contract. It is a cycle of repetitive events that cause a thin filament to slide over a thick filament and generate tension in the muscle. It was independently developed by Andrew Huxley and Rolf Niedergerke and by Hugh Huxley and Jean Hanson in 1954. Physiologically, this contraction is not uniform across the sarcomere; the central position of the thick filaments becomes unstable and can shift during contraction but this is countered by the actions of the elastic myofilament of titin. This fine myofilament maintains uniform tension across the sarcomere by pulling the thick filament into a central position.
Machine learning in video games OpenAI Five Machine_learning_in_video_games > Deep learning agents > Dota 2 > OpenAI Five OpenAI Five utilized separate LSTM networks to learn each hero. It trained using a reinforcement learning technique known as Proximal Policy Learning running on a system containing 256 GPUs and 128,000 CPU cores. Five trained for months, accumulating 180 years of game experience each day, before facing off with professional players. It was eventually able to beat the 2018 Dota 2 esports champion team in a 2019 series of games.
Addition to pi ligands Rule 3 Addition_to_pi_ligands > Rule 3 L n − M δ + − C ≡ O δ + {\displaystyle {\ce {L_{\mathit {n}}-{}}}{\overset {\color {Red}\delta +}{\ce {M}}}{\ce {-C#}}{\overset {\color {Red}\delta +}{\ce {O}}}} Incoming nucleophilic attack happens at one of the termini of the π-system in the figure below: In this example the ring system can be thought of as analogous to 1,3-butadiene. Following the Green–Davies–Mingos rules, since butadiene is an open π-ligand of even hapticity, nucleophilic attack will occur at one of the terminal positions of the π-system. This occurs because the LUMO of butadiene has larger lobes on the ends rather than the internal positions.
Adversarial Design Summary Adversarial_Design Adversarial Design is a type of political design that evokes and engages political issues. In doing so, the cultural production of Adversarial Design crosses all disciplinary boundaries in the construction of objects, interfaces, networks, spaces and events. Most importantly, Adversarial Design does the work in expressing and enabling agonism.
Coronary artery bypass graft Post-operative care Coronary_artery_bypass > Post-operative care After the procedure, the patient is usually transferred to the intensive care unit (ICU), where intubations are removed if not already done in the operating theater. They usually exit the ICU by the following day, and four days later, if no complications occur, the patient is discharged from the hospital.A series of drugs are commonly used in early post-operative care. Dobutamine, a beta agent, can increase the cardiac output and is administered some hours after the operation. Beta blockers are used to prevent atrial fibrillation and other supraventricular arrhythmias.
Bacterioplankton Photosynthetic bacterioplankton Bacterioplankton > Major groups > Photosynthetic bacterioplankton Green bacteria have different light harvesting pigments consisting of bacteriochlorophyll c, d and e. These organisms do not produce oxygen through photosynthesis or use water as a reducing agent. Many of these organisms use sulfur, hydrogen or other compounds as an energy source to drive photosynthesis. Most of these bacterioplankton are found in anoxic waters, including stagnant and hypersaline environments.
Parkinson disease The neuroimmune connection Parkinson_disease > Pathophysiology > The neuroimmune connection Mast cell degranulation and subsequent proinflammatory cytokine release is implicated in BBB breakdown in PD. Another immune cell implicated in PD are peripheral monocytes and have been found in the substantia nigra of PD patients. These monocytes can lead to more dopaminergic connection breakdown.
Esterase Summary Esterase An esterase is a hydrolase enzyme that splits esters into an acid and an alcohol in a chemical reaction with water called hydrolysis. A wide range of different esterases exist that differ in their substrate specificity, their protein structure, and their biological function.
Indentation size effect Summary Indentation_size_effect The indentation size effect (ISE) is the observation that hardness tends to increase as the indent size decreases at small scales. When an indent (any small mark, but usually made with a special tool) is created during material testing, the hardness of the material is not constant. At the small scale, materials will actually be harder than at the macro-scale.
Measurable function Notable classes of measurable functions Measurable_function > Notable classes of measurable functions Random variables are by definition measurable functions defined on probability spaces. If ( X , Σ ) {\displaystyle (X,\Sigma )} and ( Y , T ) {\displaystyle (Y,T)} are Borel spaces, a measurable function f: ( X , Σ ) → ( Y , T ) {\displaystyle f:(X,\Sigma )\to (Y,T)} is also called a Borel function. Continuous functions are Borel functions but not all Borel functions are continuous. However, a measurable function is nearly a continuous function; see Luzin's theorem.
Variable value stamp Summary Variable_value_stamp A variable value stamp, is a gummed or self-adhesive postage stamp of a common design, issued by a machine similar to an automatic teller machine (ATM), with a value of the user's choice printed at the time the stamp is dispensed. The value may be variable or from a fixed selection of postal rates. The stamps and machines are typically for use in retail or post office environments.
Immunological memory Memory B cells Immunological_memory > Adaptive immune memory > Memory B cells Memory B cells are plasma cells that are able to produce antibodies for a long time. Unlike the naive B cells involved in the primary immune response the memory B cell response is slightly different. The memory B cell has already undergone clonal expansion, differentiation and affinity maturation, so it is able to divide multiple times faster and produce antibodies with much higher affinity (especially IgG).In contrast, the naive plasma cell is fully differentiated and cannot be further stimulated by antigen to divide or increase antibody production. Memory B cell activity in secondary lymphatic organs is highest during the first 2 weeks after infection. Subsequently, after 2 to 4 weeks its response declines. After the germinal center reaction the memory plasma cells are located in the bone marrow which is the main site of antibody production within the immunological memory.
Graphical notation (music) Characteristics Graphic_notation_(music) > Characteristics Graphic notation is characterized by its variability and lack of standardization. According to Baker's Student Encyclopedia of Music, Vol. 1, "Graphic notation is used to indicate extremely precise (or intentionally imprecise) pitch or to stimulate musical behavior or actions in performance."
Deterministic simulation Model translation Deterministic_simulation > Use of simulations > Model translation It is necessary to translate models into computer recognizable formats. The modeler must decide if whether to program the model in a simulation language such as GPSS/H or to use special purpose simulation software: Arena – discrete event simulator has also academic version CSIM – CSIM is a re-usable general purpose discrete-event simulation environment for modeling complex systems of interacting elements. It contains hierarchical block diagram tools and extensive model libraries covering several domains.
Power electronics Smart grid Power_electronics > Applications > Smart grid A smart grid is a modernized electrical grid that uses information and communications technology to gather and act on information, such as information about the behaviors of suppliers and consumers, in an automated fashion to improve the efficiency, reliability, economics, and sustainability of the production and distribution of electricity.Electric power generated by wind turbines and hydroelectric turbines by using induction generators can cause variances in the frequency at which power is generated. Power electronic devices are utilized in these systems to convert the generated ac voltages into high-voltage direct current (HVDC). The HVDC power can be more easily converted into three phase power that is coherent with the power associated to the existing power grid. Through these devices, the power delivered by these systems is cleaner and has a higher associated power factor.
Weird machine Mitigation Weird_machine > Mitigation Two central categories of mitigation to the problems caused by weird machine functionality include input validation within the software and protecting against problems arising from the platform on which the program runs, such as memory errors. Input validation aims to limit the scope and forms of unexpected inputs e.g. through whitelists of allowed inputs, so that the software program itself would not end up in an unexpected state by interpreting the data internally. Equally importantly, secure programming practices such as protecting against buffer overflows make it less likely that input data becomes interpreted in unintended ways by lower layers, such as the hardware on which the program is executed.
Off-the-grid Solar photovoltaics Off-the-grid > Energy > Electrical power > Solar photovoltaics Solar photovoltaics (PV), which use energy from the sun, are one of the most popular energy solutions for off-grid buildings. PV arrays (solar panels) allow for energy from the sun to be converted into electrical energy. PV is dependent upon solar radiation and ambient temperature.
Basis of a vector space Example Basis_vector > Related notions > Analysis > Example In the study of Fourier series, one learns that the functions {1} ∪ { sin(nx), cos(nx): n = 1, 2, 3, ... } are an "orthogonal basis" of the (real or complex) vector space of all (real or complex valued) functions on the interval that are square-integrable on this interval, i.e., functions f satisfying The functions {1} ∪ { sin(nx), cos(nx): n = 1, 2, 3, ... } are linearly independent, and every function f that is square-integrable on is an "infinite linear combination" of them, in the sense that for suitable (real or complex) coefficients ak, bk. But many square-integrable functions cannot be represented as finite linear combinations of these basis functions, which therefore do not comprise a Hamel basis. Every Hamel basis of this space is much bigger than this merely countably infinite set of functions. Hamel bases of spaces of this kind are typically not useful, whereas orthonormal bases of these spaces are essential in Fourier analysis.
Ground loop (electricity) Sources of ground current Ground_potential > Common ground loops > Sources of ground current The diagram shows leakage current from an appliance such as an electric motor A flowing through the building's ground system G to the neutral wire at the utility ground bonding point at the service panel. The ground loop between components C1 and C2 creates a second parallel path for the current. The current divides, with some passing through component C1, the signal cable S ground conductor, C2 and back through the outlet into the ground system G. The AC voltage drop across the cable's ground conductor from this current introduces hum or interference into component C2.
Electronic Hamiltonian Summary Electronic_Hamiltonian From it are missing a number of small terms, most of which are due to electronic and nuclear spin. Although it is generally assumed that the solution of the time-independent Schrödinger equation associated with the Coulomb Hamiltonian will predict most properties of the molecule, including its shape (three-dimensional structure), calculations based on the full Coulomb Hamiltonian are very rare. The main reason is that its Schrödinger equation is very difficult to solve.
Autonomous research robot Outdoor operation Autonomous_research_robot > Autonomous navigation techniques > Outdoor operation Outdoors, localization is primarily handled with GPS, however, satellite signals can frequently be lost due to obstructions. Without a robots typically use dead reckoning and inertial motion tracking. Dead reckoning relies on relative wheel motion and is subject to cumulative slippage errors. Inertial motion tracking uses rate gyroscopes and accelerometers to measure motion.
Link analysis Knowledge discovery Link_analysis > Knowledge discovery Manual or computer-generated visualizations tools may be mapped from the data, including network charts. Several algorithms exist to help with analysis of data – Dijkstra’s algorithm, breadth-first search, and depth-first search. Link analysis focuses on analysis of relationships among nodes through visualization methods (network charts, association matrix). Here is an example of the relationships that may be mapped for crime investigations: Link analysis is used for 3 primary purposes: Find matches in data for known patterns of interest; Find anomalies where known patterns are violated; Discover new patterns of interest (social network analysis, data mining).
Perichromatin fibril Evolution Cell_Nucleus > Evolution The archaeal origin of the nucleus is supported by observations that archaea and eukarya have similar genes for certain proteins, including histones. Observations that myxobacteria are motile, can form multicellular complexes, and possess kinases and G proteins similar to eukarya, support a bacterial origin for the eukaryotic cell.A second model proposes that proto-eukaryotic cells evolved from bacteria without an endosymbiotic stage. This model is based on the existence of modern Planctomycetota bacteria that possess a nuclear structure with primitive pores and other compartmentalized membrane structures.
Genome-wide CRISPR-Cas9 knockout screens Arrayed vs pooled screens Genome-wide_CRISPR-Cas9_knockout_screens > Limitations > Arrayed vs pooled screens In an arrayed screen, each well contains a specific and known sgRNA targeting a specific gene. Arrayed screens therefore allow for detailed profiling of a single cell, but are limited by high costs and the labour required to isolate and culture the high number of individual cell populations. Conventional pooled CRISPR screens are relatively simple and cost effective to perform, but are limited to the study of the entire cell population. This means that rare phenotypes may be more difficult to identify, and only crude phenotypes can be selected for e.g. cell survival, proliferation, or reporter gene expression.
Minsky machine Summary Minsky_machine In mathematical logic and theoretical computer science, a register machine is a generic class of abstract machines used in a manner similar to a Turing machine. All the models are Turing equivalent.
Pythagorean hammers Contents of the legend Pythagorean_hammers > Contents of the legend For the dissonant interval between fifth and fourth, it was revealed that it was based on the ratio 9:8, which coincided with the weight measurements carried out in the forge. The octave proved to be the product of the fifth and fourth: 3 2 ⋅ 4 3 = 12 6 = 2 1 = 2 {\displaystyle {\frac {3}{2}}\cdot {\frac {4}{3}}={\frac {12}{6}}={\frac {2}{1}}=2} Pythagoras then extended the experiment to various instruments, experimented with vessels, flutes, triangles, the Monochord, etc., always finding the same numerical ratios. Finally, he introduced the commonly used terminology for relative pitch.
Alternative splicing Adaptive significance Alternatively_spliced > Adaptive significance Genuine alternative splicing occurs in both protein-coding genes and non-coding genes to produce multiple products (proteins or non-coding RNAs). External information is needed in order to decide which product is made, given a DNA sequence and the initial transcript. Since the methods of regulation are inherited, this provides novel ways for mutations to affect gene expression.Alternative splicing may provide evolutionary flexibility.
Just in time compiler History Just-in-time_compilation > History Self was abandoned by Sun, but the research went into the Java language. The term "Just-in-time compilation" was borrowed from the manufacturing term "Just in time" and popularized by Java, with James Gosling using the term from 1993. Currently JITing is used by most implementations of the Java Virtual Machine, as HotSpot builds on, and extensively uses, this research base. The HP project Dynamo was an experimental JIT compiler where the 'bytecode' format and the machine code format were the same; the system optimized PA-8000 machine code. Counterintuitively, this resulted in speed ups, in some cases of 30% since doing this permitted optimizations at the machine code level, for example, inlining code for better cache usage and optimizations of calls to dynamic libraries and many other run-time optimizations which conventional compilers are not able to attempt.In November 2020, PHP 8.0 introduced a JIT compiler.
Language equation Summary Language_equation Language equations are mathematical statements that resemble numerical equations, but the variables assume values of formal languages rather than numbers. Instead of arithmetic operations in numerical equations, the variables are joined by language operations. Among the most common operations on two languages A and B are the set union A ∪ B, the set intersection A ∩ B, and the concatenation A⋅B. Finally, as an operation taking a single operand, the set A* denotes the Kleene star of the language A. Therefore language equations can be used to represent formal grammars, since the languages generated by the grammar must be the solution of a system of language equations.
Interpersonal communication Relevance to mass communication Interpersonal_communication > Relevance to mass communication Interpersonal communication has been studied as a mediator for information flow from mass media to the wider population. The two-step flow of communication theory proposes that most people form their opinions under the influence of opinion leaders, who in turn are influenced by the mass media. Many studies have repeated this logic in investigating the effects of personal and mass communication, for example in election campaigns and health-related information campaigns.It is not clear whether or how social networking through sites such as Facebook changes this picture. Social networking is conducted over electronic devices with no face-to-face interaction, resulting in an inability to access the behavior of the communicator and the nonverbal signals that facilitate communication. Side effects of using these technologies for communication may not always be apparent to the individual user, and may involve both benefits and risks.
Cognitive ergonomics History Cognitive_ergonomics > History The field of cognitive ergonomics emerged predominantly in the 70's with the advent of the personal computer and new developments in the fields of cognitive psychology and artificial intelligence. It studied how human cognitive psychology works hand-in-hand with specific cognitive limitations. This could only be done through time and trial and error. CE contrasts the tradition of physical ergonomics because "cognitive ergonomics is...the application of psychology to work...to achieve the optimization between people and their work."
Computerized adaptive testing Pass-fail Computerized_adaptive_testing > Other issues > Pass-fail Note that this is a point hypothesis formulation rather than a composite hypothesis formulation that is more conceptually appropriate. A composite hypothesis formulation would be that the examinee's ability is in the region above the cutscore or the region below the cutscore. A confidence interval approach is also used, where after each item is administered, the algorithm determines the probability that the examinee's true-score is above or below the passing score.
164 (number) In other fields 164_(number) > In other fields 164 is also: The year AD 164 or 164 BC 164 AH is a year in the Islamic calendar that corresponds to 780 – 781 CE The Scrabble board, a 15-by-15 grid, includes 164 squares that have neither word nor letter multiplier. The remainder have attributes such as double letter, triple letter, double word, and triple word The atomic number of an element temporarily called Unhexquadium Solvent Red 164 is a synthetic red diazo dye E.164 is an ITU-T recommendation defines public telecommunication numbering plan used in the PSTN and data networks
Immune tolerance Definitions and usage Immunologic_tolerance > Definitions and usage Immune tolerance is formally differentiated into central or peripheral; however, alternative terms such as "natural" or "acquired" tolerance have at times been used to refer to establishment of tolerance by physiological means or by artificial, experimental, or pharmacological means. These two methods of categorization are sometimes confused, but are not equivalent—central or peripheral tolerance may be present naturally or induced experimentally. This difference is important to keep in mind.
Software lockout Kernel-level critical sections Software_lockout > Kernel-level critical sections To prevent critical races and inconsistency, only one processor (CPU) at a given time is allowed to access a particular data structure (a memory portion), while other CPUs trying to access at the same time are locked-out, waiting in idle status.Three cases can be distinguished when this idle wait is either necessary, convenient, or not convenient. The idle wait is necessary when the access is to a ready list for a low level scheduling operation. The idle wait is not necessary but convenient in the case of a critical section for synchronization/IPC operations, which require less time than a context switch (executing another process to avoid idle wait).
Applications of AI Automotive Applications_of_AI > Transport > Automotive A group of autonomous trucks follow closely behind each other. German corporation Daimler is testing its Freightliner Inspiration.Autonomous vehicles require accurate maps to be able to navigate between destinations. Some autonomous vehicles do not allow human drivers (they have no steering wheels or pedals).
Mechanical advantage Block and tackle Mechanical_advantage > Block and tackle A block and tackle is an assembly of a rope and pulleys that is used to lift loads. A number of pulleys are assembled together to form the blocks, one that is fixed and one that moves with the load. The rope is threaded through the pulleys to provide mechanical advantage that amplifies that force applied to the rope.In order to determine the mechanical advantage of a block and tackle system consider the simple case of a gun tackle, which has a single mounted, or fixed, pulley and a single movable pulley. The rope is threaded around the fixed block and falls down to the moving block where it is threaded around the pulley and brought back up to be knotted to the fixed block.
Exponential random graph models Background Exponential_family_random_graph_models > Background Many metrics exist to describe the structural features of an observed network such as the density, centrality, or assortativity. However, these metrics describe the observed network which is only one instance of a large number of possible alternative networks. This set of alternative networks may have similar or dissimilar structural features. To support statistical inference on the processes influencing the formation of network structure, a statistical model should consider the set of all possible alternative networks weighted on their similarity to an observed network.

Subsets and Splits

No community queries yet

The top public SQL queries from the community will appear here once available.