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Spatial variability Summary Spatial_variability Spatial variability occurs when a quantity that is measured at different spatial locations exhibits values that differ across the locations. Spatial variability can be assessed using spatial descriptive statistics such as the range. Let us suppose that the Rev' z(x) is perfectly known at any point x within the field under study. Then the uncertainty about z(x) is reduced to zero, whereas its spatial variability still exists. |
Population parameter Examples Statistical_parameter > Examples Similarly, in some forms of testing of manufactured products, rather than destructively testing all products, only a sample of products are tested. Such tests gather statistics supporting an inference that the products meet specifications. == References == |
Peripheral nerves Enteric nervous system Peripheral_nerves > Structure > Autonomic nervous system > Enteric nervous system There is a lesser known division of the autonomic nervous system known as the enteric nervous system. Located only around the digestive tract, this system allows for local control without input from the sympathetic or the parasympathetic branches, though it can still receive and respond to signals from the rest of the body. The enteric system is responsible for various functions related to gastrointestinal system. |
Scharnhorst effect Possible experimentation Scharnhorst_effect > Possible experimentation It may be possible to amplify the Scharnhorst effect by replacing Casimir plates with event horizons, an idea informally suggested by American physicist Timothy Retter. In this space, even fewer virtual particles will be present than between Casimir plates, thus magnifying the effect. He suggests that rather than light becoming superluminal, that the speed of light c should be redefined to account for this improved medium. == References == |
ATM protein Meiosis ATM_serine/threonine_kinase > Meiosis Deficient ATM expression causes severe meiotic disruption during prophase I. In addition, impaired ATM-mediated DNA DSB repair has been identified as a likely cause of aging of mouse and human oocytes. Expression of the ATM gene, as well as other key DSB repair genes, declines with age in mouse and human oocytes and this decline is paralleled by an increase of DSBs in primordial follicles. These findings indicate that ATM-mediated homologous recombinational repair is a crucial function of meiosis. |
Strong electrolyte Summary Strong_electrolyte A concentrated solution of this strong electrolyte has a lower vapor pressure than that of pure water at the same temperature. Strong acids, strong bases and soluble ionic salts that are not weak acids or weak bases are strong electrolytes. A substance whose aqueous solution or molten state decomposed into ions by passing electricity is known as electrolytes. |
Finite state machines Determinism State_Machine > Classification > Determinism A further distinction is between deterministic (DFA) and non-deterministic (NFA, GNFA) automata. In a deterministic automaton, every state has exactly one transition for each possible input. In a non-deterministic automaton, an input can lead to one, more than one, or no transition for a given state. The powerset construction algorithm can transform any nondeterministic automaton into a (usually more complex) deterministic automaton with identical functionality. |
Estrin's scheme Summary Estrin's_scheme In numerical analysis, Estrin's scheme (after Gerald Estrin), also known as Estrin's method, is an algorithm for numerical evaluation of polynomials. Horner's method for evaluation of polynomials is one of the most commonly used algorithms for this purpose, and unlike Estrin's scheme it is optimal in the sense that it minimizes the number of multiplications and additions required to evaluate an arbitrary polynomial. On a modern processor, instructions that do not depend on each other's results may run in parallel. Horner's method contains a series of multiplications and additions that each depend on the previous instruction and so cannot execute in parallel. Estrin's scheme is one method that attempts to overcome this serialization while still being reasonably close to optimal. |
Romano–Ward syndrome Treatment Romano–Ward_syndrome > Treatment Potassium supplements may be used at times when potassium is being lost such as when experiencing diarrhoea or vomiting, but medications that encourage the retention of potassium such as spironolactone or amiloride may also be required.An implantable defibrillator, a small device that monitors the heart rhythm and can automatically deliver an electric shock to restart the heart, may be recommended. These devices are recommended for those with Romano–Ward syndrome who have experienced a cardiac arrest or a blackout whilst taking beta blockers. In those who experience recurrent arrhythmias despite medical therapy, a surgical procedure called sympathetic denervation can be used to interrupt the nerves that stimulate the heart. |
Insulin signal transduction pathway Insulin secretion Insulin_signal_transduction_pathway > Transduction pathway > Insulin secretion The glucose that goes into the bloodstream after food consumption also enters the beta cells in the Islets of Langerhans in the pancreas. The glucose diffuses in the beta-cell facilitated by a GLUT-2 vesicle. Inside the beta cell, the following process occurs: Glucose gets converted to Glucose-6-Phosphate (G6P) through Glucokinase, and G6P is subsequently oxidized to form ATP. This process inhibits the ATP-sensitive potassium ion channels of the cell causing the Potassium ion channel to close and not function anymore. |
Multidimensional Scaling Procedure Multi_dimensional_scaling_(in_marketing) > Procedure Decide number of dimensions – The researcher must decide on the number of dimensions they want the computer to create. Interpretability of the MDS solution is often important, and lower dimensional solutions will typically be easier to interpret and visualize. However, dimension selection is also an issue of balancing underfitting and overfitting. |
Minimum description length Recent work on algorithmic MDL learning Minimum_description_length > Recent work on algorithmic MDL learning Recent machine MDL learning of algorithmic, as opposed to statistical, data models have received increasing attention with increasing availability of data, computation resources and theoretic advances. Approaches are informed by the burgeoning field of artificial general intelligence. Shortly before his death, Marvin Minsky came out strongly in favor of this line of research, saying: It seems to me that the most important discovery since Gödel was the discovery by Chaitin, Solomonoff and Kolmogorov of the concept called Algorithmic Probability which is a fundamental new theory of how to make predictions given a collection of experiences and this is a beautiful theory, everybody should learn it, but it’s got one problem, that is, that you cannot actually calculate what this theory predicts because it is too hard, it requires an infinite amount of work. However, it should be possible to make practical approximations to the Chaitin, Kolmogorov, Solomonoff theory that would make better predictions than anything we have today. Everybody should learn all about that and spend the rest of their lives working on it. |
Polymer physics Random walks in time Polymer_physics > Example model (simple random-walk, freely jointed) > Random walks in time Suppose that the train moves either a distance of +b or −b (b is the same for each step), depending on whether a coin lands heads or tails when flipped. Lets start by considering the statistics of the steps the toy train takes (where Si is the ith step taken): ⟨ S i ⟩ = 0 {\displaystyle \langle S_{i}\rangle =0} ; due to a priori equal probabilities ⟨ S i S j ⟩ = b 2 δ i j . {\displaystyle \langle S_{i}S_{j}\rangle =b^{2}\delta _{ij}.} |
Grid tie inverter Summary Grid_tie_inverter A grid-tie inverter converts direct current (DC) into an alternating current (AC) suitable for injecting into an electrical power grid, normally 120 V RMS at 60 Hz or 240 V RMS at 50 Hz. Grid-tie inverters are used between local electrical power generators: solar panel, wind turbine, hydro-electric, and the grid.To inject electrical power efficiently and safely into the grid, grid-tie inverters must accurately match the voltage, frequency and phase of the grid sine wave AC waveform. |
EST1 Aging Telomerase > Clinical implications > Aging In human liver, cholangiocytes and hepatocytes show no age-related telomere shortening. Another study found little evidence that, in humans, telomere length is a significant biomarker of normal aging with respect to important cognitive and physical abilities.Some experiments have raised questions on whether telomerase can be used as an anti-aging therapy, namely, the fact that mice with elevated levels of telomerase have higher cancer incidence and hence do not live longer. On the other hand, one study showed that activating telomerase in cancer-resistant mice by overexpressing its catalytic subunit extended lifespan. A study found that long-lived subjects inherited a hyperactive version of telomerase. |
MinHash Variant with many hash functions MinHash > Algorithm > Variant with many hash functions The simplest version of the minhash scheme uses k different hash functions, where k is a fixed integer parameter, and represents each set S by the k values of hmin(S) for these k functions. To estimate J(A,B) using this version of the scheme, let y be the number of hash functions for which hmin(A) = hmin(B), and use y/k as the estimate. This estimate is the average of k different 0-1 random variables, each of which is one when hmin(A) = hmin(B) and zero otherwise, and each of which is an unbiased estimator of J(A,B). Therefore, their average is also an unbiased estimator, and by standard deviation for sums of 0-1 random variables, its expected error is O(1/√k).Therefore, for any constant ε > 0 there is a constant k = O(1/ε2) such that the expected error of the estimate is at most ε. For example, 400 hashes would be required to estimate J(A,B) with an expected error less than or equal to .05. |
ALTQ Summary ALTQ Each queue can have a priority and a bandwidth assigned. Priority mainly controls the time packets take to get sent out, while bandwidth has primarily effects on throughput. |
Glossary of mathematical symbols Infinite numbers Math_symbol > Infinite numbers 5. In number theory, may denote the prime omega function. That is, ω ( n ) {\displaystyle \omega (n)} is the number of distinct prime factors of the integer n. |
Stacked bar graph Summary Bar_graph A bar graph shows comparisons among discrete categories. One axis of the chart shows the specific categories being compared, and the other axis represents a measured value. Some bar graphs present bars clustered in groups of more than one, showing the values of more than one measured variable. |
Energy technology Thermodynamics Energy_technologies > Energy technology > Thermodynamics Thermodynamics deals with the fundamental laws of energy conversion and is drawn from theoretical Physics. |
Tangential velocity Related quantities Tangential_speed > Related quantities When a direction is assigned to rotational speed, it is known as rotational velocity, a vector whose magnitude is the rotational speed. (Angular speed and angular velocity are related to the rotational speed and velocity by a factor of 2π, the number of radians turned in a full rotation.) Tangential speed and rotational speed are related: the greater the "RPMs", the larger the speed in metres per second. |
Jacobi ellipsoid Summary Jacobi_ellipsoid A Jacobi ellipsoid is a triaxial (i.e. scalene) ellipsoid under hydrostatic equilibrium which arises when a self-gravitating, fluid body of uniform density rotates with a constant angular velocity. It is named after the German mathematician Carl Gustav Jacob Jacobi. |
Microsoft WebMatrix Summary Microsoft_WebMatrix Microsoft WebMatrix is a discontinued cloud-connected website builder and HTML editor for Windows, geared towards web development. WebMatrix enables developers to build websites using built-in templates or popular open-source applications, with full support for ASP.NET, PHP, Node.js and HTML5. Microsoft developed WebMatrix for the purpose of providing web developers with coding, customization, and publishing capabilities all in one place. |
Data Matrix Applications Data_matrix_(computer) > Applications The US Electronic Industries Alliance (EIA) recommends using Data Matrix for labeling small electronic components.Data Matrix codes are becoming common on printed media such as labels and letters. The code can be read quickly by a barcode reader which allows the media to be tracked, for example when a parcel has been dispatched to the recipient. For industrial engineering purposes, Data Matrix codes can be marked directly onto components, ensuring that only the intended component is identified with the data-matrix-encoded data. |
Dictionary-based machine translation LMT Dictionary-based_machine_translation > LMT LMT, introduced around 1990, is a Prolog-based machine-translation system that works on specially made bilingual dictionaries, such as the Collins English-German (CEG), which have been rewritten in an indexed form which is easily readable by computers. This method uses a structured lexical data base (LDB) in order to correctly identify word categories from the source language, thus constructing a coherent sentence in the target language, based on rudimentary morphological analysis. This system uses "frames" to identify the position a certain word should have, from a syntactical point of view, in a sentence. This "frames" are mapped via language conventions, such as UDICT in the case of English. |
Bicycle and motorcycle dynamics Vibration Bike_physics > Vibration A challenge in vibration damping is to create compliance in certain directions (vertically) without sacrificing frame rigidity needed for power transmission and handling (torsionally). Another issue with vibration for the bike is the possibility of failure due to material fatigue Effects of vibration on riders include discomfort, loss of efficiency, Hand-Arm Vibration Syndrome, a secondary form Raynaud's disease, and whole body vibration. Vibrating instruments may be inaccurate or difficult to read. |
Convolution operation Summary Convolution_kernel Convolution has applications that include probability, statistics, acoustics, spectroscopy, signal processing and image processing, geophysics, engineering, physics, computer vision and differential equations.The convolution can be defined for functions on Euclidean space and other groups (as algebraic structures). For example, periodic functions, such as the discrete-time Fourier transform, can be defined on a circle and convolved by periodic convolution. (See row 18 at DTFT § Properties.) A discrete convolution can be defined for functions on the set of integers. Generalizations of convolution have applications in the field of numerical analysis and numerical linear algebra, and in the design and implementation of finite impulse response filters in signal processing.Computing the inverse of the convolution operation is known as deconvolution. |
Sun synchronous orbit Technical details Sun-synchronous_orbit > Technical details Earth observation satellites, in particular, prefer orbits with constant altitude when passing over the same spot. Careful selection of eccentricity and location of perigee reveals specific combinations where the rate of change of perturbations are minimized, and hence the orbit is relatively stable – a frozen orbit, where the motion of position of the periapsis is stable. The ERS-1, ERS-2 and Envisat of European Space Agency, as well as the MetOp spacecraft of EUMETSAT and RADARSAT-2 of the Canadian Space Agency, are all operated in such Sun-synchronous frozen orbits. |
Undefined behavior Overview Undefined_behaviour > Overview Some programming languages allow a program to operate differently or even have a different control flow than the source code, as long as it exhibits the same user-visible side effects, if undefined behavior never happens during program execution. Undefined behavior is the name of a list of conditions that the program must not meet. In the early versions of C, undefined behavior's primary advantage was the production of performant compilers for a wide variety of machines: a specific construct could be mapped to a machine-specific feature, and the compiler did not have to generate additional code for the runtime to adapt the side effects to match semantics imposed by the language. The program source code was written with prior knowledge of the specific compiler and of the platforms that it would support. |
Identity-based encryption Encryption schemes Identity_based_encryption > Encryption schemes Another approach to identity-based encryption was proposed by Clifford Cocks in 2001. The Cocks IBE scheme is based on well-studied assumptions (the quadratic residuosity assumption) but encrypts messages one bit at a time with a high degree of ciphertext expansion. Thus it is highly inefficient and impractical for sending all but the shortest messages, such as a session key for use with a symmetric cipher. A third approach to IBE is through the use of lattices. |
History of mathematical notation Derivatives notation: Leibniz and Newton History_of_mathematical_notation > Symbolic stage > Derivatives notation: Leibniz and Newton Leibniz also created the integral symbol. The symbol is an elongated S, representing the Latin word Summa, meaning "sum". When finding areas under curves, integration is often illustrated by dividing the area into infinitely many tall, thin rectangles, whose areas are added. Thus, the integral symbol is an elongated s, for sum. |
Optical telescopes Large reflectors Optical_telescope > Astronomical research telescopes > Large reflectors For conventional telescopes on Earth, the diffraction limit is not relevant for telescopes bigger than about 10 cm. Instead, the seeing, or blur caused by the atmosphere, sets the resolution limit. But in space, or if adaptive optics are used, then reaching the diffraction limit is sometimes possible. |
Function evaluation Functional notation Bivariate_function > Notation > Functional notation When the symbol denoting the function consists of several characters and no ambiguity may arise, the parentheses of functional notation might be omitted. For example, it is common to write sin x instead of sin(x). |
CH3CH(OH)COOH Chemical production CH3CH(OH)COOH > Production > Chemical production Racemic lactic acid is synthesized industrially by reacting acetaldehyde with hydrogen cyanide and hydrolysing the resultant lactonitrile. When hydrolysis is performed by hydrochloric acid, ammonium chloride forms as a by-product; the Japanese company Musashino is one of the last big manufacturers of lactic acid by this route. Synthesis of both racemic and enantiopure lactic acids is also possible from other starting materials (vinyl acetate, glycerol, etc.) by application of catalytic procedures. |
Vehicle tracking Active versus passive tracking Vehicle_tracking_system > Active versus passive tracking Several types of vehicle tracking devices exist. Typically they are classified as "passive" and "active". "Passive" devices store GPS location, speed, heading and sometimes a trigger event such as key on/off, door open/closed. Once the vehicle returns to a predetermined point, the device is removed and the data downloaded to a computer for evaluation. |
Glossary of engineering: M–Z T Glossary_of_engineering:_M–Z > T Trigonometric functionsIn mathematics, the trigonometric functions (also called circular functions, angle functions or goniometric functions) are real functions which relate an angle of a right-angled triangle to ratios of two side lengths. They are widely used in all sciences that are related to geometry, such as navigation, solid mechanics, celestial mechanics, geodesy, and many others. They are among the simplest periodic functions, and as such are also widely used for studying periodic phenomena through Fourier analysis. |
Kinetic isotope effect Theory Kinetic_isotope_effect > Theory However, a quantum-mechanical treatment of the energy introduces discrete vibrational levels onto this curve, and the lowest possible energy state of a molecule corresponds to the lowest vibrational energy level, which is slightly higher in energy than the minimum of the potential energy curve. This difference, referred to as the zero-point energy, is a manifestation of the Heisenberg uncertainty principle that necessitates an uncertainty in the C-H or C-D bond length. Since the heavier (in this case the deuterated) species behaves more "classically," its vibrational energy levels are closer to the classical potential energy curve, and it has a lower zero-point energy. |
DeepRoute.ai Partnerships DeepRoute.ai > Partnerships Since its founding, DeepRoute.ai has formed many successful partnerships. Its most recent partnership, announced in August 2022, is with the technology giant, Microsoft. DeepRoute.ai will utilize Microsoft’s cloud and edge computing platform, Microsoft Azure. The partnership aims to push forward DeepRoute.ai’s global deployment and accelerate the mass production of Level 4 autonomous vehicles while further boosting the safety of DeepRoute.ai’s self-driving systems outside of China. |
Passive analogue filter development Transmission line theory Voice_frequency_telegraphy > Transmission line theory The cut-off phenomenon is an undesirable side-effect as far as loaded lines are concerned but for telephone FDM filters it is precisely what is required. For this application, Campbell produced band-pass filters to the same ladder topology by replacing the inductors and capacitors with resonators and anti-resonators respectively. Both the loaded line and FDM were of great benefit economically to AT&T and this led to fast development of filtering from this point onwards. |
Abbe refractometer Summary Abbe_refractometer An Abbe refractometer is a bench-top device for the high-precision measurement of an index of refraction. |
Septic shock Epidemiology Septic_shock > Epidemiology Sepsis has a worldwide incidence of more than 20 million cases a year, with mortality due to septic shock reaching up to 50 percent even in industrialized countries.According to the U.S. Centers for Disease Control, septic shock is the thirteenth leading cause of death in the United States and the most frequent cause of death in intensive care units. There has been an increase in the rate of septic shock deaths in recent decades, which is attributed to an increase in invasive medical devices and procedures, increases in immunocompromised patients, and an overall increase in elderly patients.Tertiary care centers (such as hospice care facilities) have 2-4 times the rate of bacteremia than primary care centers, 75% of which are hospital-acquired infections.The process of infection by bacteria or fungi may result in systemic signs and symptoms that are variously described. |
LS-DYNA Typical uses LS-DYNA > Typical uses Nonlinear means at least one (and sometimes all) of the following complications: Changing boundary conditions (such as contact between parts that changes over time) Large deformations (for example the crumpling of sheet metal parts) Nonlinear materials that do not exhibit ideally elastic behavior (for example thermoplastic polymers)Transient dynamic means analyzing high speed, short duration events where inertial forces are important. Typical uses include: Automotive crash (deformation of chassis, airbag inflation, seatbelt tensioning, ...) Explosions (underwater mines, shaped charges, ...) Manufacturing (sheet metal stamping, ...) |
Recursive neural network Tree Echo State Networks Recursive_neural_network > Related models > Tree Echo State Networks An efficient approach to implement recursive neural networks is given by the Tree Echo State Network within the reservoir computing paradigm. |
Arbitrated loop Summary Arbitrated_loop A loop with two ports is valid and has the same physical topology as point-to-point, but still acts as a loop protocol-wise. Fibre Channel ports capable of arbitrated loop communication are NL_port (node loop port) and FL_port (fabric loop port), collectively referred to as the L_ports. The ports may attach to each other via a hub, with cables running from the hub to the ports. |
Jitter buffer Filtering and decomposition Jitter_buffer > Mitigation > Filtering and decomposition A filter can be designed to minimize the effect of sampling jitter.Jitter signal can be decomposed into intrinsic mode functions (IMFs), which can be further applied for filtering or dejittering. |
Polynomial system Summary Polynomial_system_solving A system of polynomial equations (sometimes simply a polynomial system) is a set of simultaneous equations f1 = 0, ..., fh = 0 where the fi are polynomials in several variables, say x1, ..., xn, over some field k. A solution of a polynomial system is a set of values for the xis which belong to some algebraically closed field extension K of k, and make all equations true. When k is the field of rational numbers, K is generally assumed to be the field of complex numbers, because each solution belongs to a field extension of k, which is isomorphic to a subfield of the complex numbers. This article is about the methods for solving, that is, finding all solutions or describing them. As these methods are designed for being implemented in a computer, emphasis is given on fields k in which computation (including equality testing) is easy and efficient, that is the field of rational numbers and finite fields. Searching for solutions that belong to a specific set is a problem which is generally much more difficult, and is outside the scope of this article, except for the case of the solutions in a given finite field. For the case of solutions of which all components are integers or rational numbers, see Diophantine equation. |
Medical ethics Between autonomy and beneficence/non-maleficence Medical_ethics > Conflicts > Between autonomy and beneficence/non-maleficence On the other hand, autonomy and beneficence/non-maleficence may also overlap. For example, a breach of patients' autonomy may cause decreased confidence for medical services in the population and subsequently less willingness to seek help, which in turn may cause inability to perform beneficence. The principles of autonomy and beneficence/non-maleficence may also be expanded to include effects on the relatives of patients or even the medical practitioners, the overall population and economic issues when making medical decisions. |
Metastatic disease Hematogenous spread Metastatic_relapse > Pathophysiology > Routes > Hematogenous spread This is typical route of metastasis for sarcomas, but it is also the favored route for certain types of carcinoma, such as renal cell carcinoma originating in the kidney and follicular carcinomas of the thyroid. Because of their thinner walls, veins are more frequently invaded than are arteries, and metastasis tends to follow the pattern of venous flow. That is, hematogenous spread often follows distinct patterns depending on the location of the primary tumor. For example, colorectal cancer spreads primarily through the portal vein to the liver. |
Claw finding problem Definition Claw_finding_problem > Definition Let A , B , C {\displaystyle A,B,C} be finite sets, and f: A → C {\displaystyle f:A\to C} , g: B → C {\displaystyle g:B\to C} two functions. A pair ( x , y ) ∈ A × B {\displaystyle (x,y)\in A\times B} is called a claw if f ( x ) = g ( y ) {\displaystyle f(x)=g(y)} . The claw finding problem is defined as to find such a claw, given that one exists. |
CAN controller Standardized approaches CAN_bus_monitor > CAN-based higher-layer protocols > Standardized approaches ARINC 812 or ARINC 825 (aviation industry) CANopen - CiA 301/302-2 and EN 50325-4 (industrial automation) IEC 61375-3-3 (use of CANopen in rail vehicles) DeviceNet (industrial automation) EnergyBus - CiA 454 and IEC 61851-3 (battery–charger communication) ISOBUS - ISO 11783 (agriculture) ISO-TP - ISO 15765-2 (transport protocol for automotive diagnostics) MilCAN (military vehicles) NMEA 2000 - IEC 61162-3 (marine industry) SAE J1939 (in-vehicle network for buses and trucks) SAE J2284 (in-vehicle networks for passenger cars) Unified Diagnostic Services (UDS) - ISO 14229 (automotive diagnostics) LeisureCAN - open standard for the leisure craft/vehicle industry |
Neuromyelitis optica Anti-MOG+ variants Devic's_disease > Pathophysiology > Anti-MOG+ variants The NMO cases are classified in four classes, according to the presence or absence of any of these two main auto-antibodies.The clinical course and the response to therapy is different for various diseases classed within these groups, showing a better prognosis for those in the NMO-Ab(−)/MOG-Ab(−) group, and a worse prognosis for those in the NMO-Ab(+)/MOG-Ab(+) group. The MOG-related NMO can be radiologically identified by the conus involvement. Myelin-oligodendrocyte glycoprotein antibody–positive patients were more likely to have conus involvement on spinal magnetic resonance imaging. |
Major depressive disorder Symptoms and signs Major_depression_disorder > Symptoms and signs Family and friends may notice agitation or lethargy. Older depressed people may have cognitive symptoms of recent onset, such as forgetfulness, and a more noticeable slowing of movements.Depressed children may often display an irritable rather than a depressed mood; most lose interest in school and show a steep decline in academic performance. Diagnosis may be delayed or missed when symptoms are interpreted as "normal moodiness." Elderly people may not present with classical depressive symptoms. Diagnosis and treatment is further complicated in that the elderly are often simultaneously treated with a number of other drugs, and often have other concurrent diseases. |
Internet Of Things Trends and characteristics Internet_of_Everything > Trends and characteristics The IoT's major significant trend in recent years is the explosive growth of devices connected and controlled via the Internet. The wide range of applications for IoT technology mean that the specifics can be very different from one device to the next but there are basic characteristics shared by most. The IoT creates opportunities for more direct integration of the physical world into computer-based systems, resulting in efficiency improvements, economic benefits, and reduced human exertions.The number of IoT devices increased 31% year-over-year to 8.4 billion in the year 2017 and it is estimated that there will be 30 billion devices by 2020. |
State equation Perturbation theory-based models Virial_equation > Physically based equations of state > Perturbation theory-based models Perturbation theory is frequently used for modelling dispersive interactions in an equation of state. There is a large number of perturbation theory based equations of state available today, e.g. for the classical Lennard-Jones fluid. The two most important theories used for these types of equations of state are the Barker-Henderson perturbation theory and the Weeks–Chandler–Andersen perturbation theory. |
Purinergic signalling Digestive system Purinergic_signalling > Purinergic signalling in humans > Digestive system In the liver, ATP is constantly released during homeostasis and its signalling via P2 receptors influences bile secretion as well as liver metabolism and regeneration. P2Y receptors in the enteric nervous system and at intestinal neuromuscular junctions modulate intestinal secretion and motility. |
Axo-axonic synapse Clinical Significance Axo-axonic_synapse > Clinical Significance They proposed that these axo-axonic synapses in the striatum could be responsible for inhibiting the glutamatergic neurons. Additionally, these dopaminergic synapses are also proposed to cause hyperdopaminergic activity and become neurotoxic for the postsynaptic glutamatergic neurons. This mechanism is proposed to be a possible mechanism for glutamate dysfunction in observed schizophrenia. |
Dm-cache Design Dm-cache > Design In dm-cache, creating a mapped virtual block device that acts as a hybrid volume requires three physical storage devices: Origin device – provides slow primary storage (usually an HDD) Cache device – provides a fast cache (usually an SSD) Metadata device – records the placement of blocks and their dirty flags, as well as other internal data required by a cache policy, including per-block hit counts; a metadata device cannot be shared between multiple cache devices, and it is recommended to be mirroredInternally, dm-cache references to each of the origin devices through a number of fixed-size blocks; the size of these blocks, equaling to the size of a caching extent, is configurable only during the creation of a hybrid volume. The size of a caching extent must range between 32 KB and 1 GB, and it must be a multiple of 32 KB; typically, the size of a caching extent is between 256 and 1024 KB. The choice of the caching extents bigger than disk sectors acts a compromise between the size of metadata and the possibility for wasting cache space. |
Sedimentary deposits Types and history Superficial_deposits > Types and history Superficial deposits were originally recorded only onshore and around the coast where they were laid down by various natural processes such as action by ice, water and wind. More recently offshore deposits have been mapped and may be separate sea-bed sediments. Most of these superficial deposits are unconsolidated sediments such as gravel, sand, silt and clay, and onshore they form relatively thin, often discontinuous patches. Almost all of these deposits were formerly classified on the basis of mode of origin with names such as, 'glacial deposits', 'river terrace deposits' or 'blown sand'; or on their composition such as 'peat'. |
Bayes classifier Definition Bayes_classifier > Definition Suppose a pair ( X , Y ) {\displaystyle (X,Y)} takes values in R d × { 1 , 2 , … , K } {\displaystyle \mathbb {R} ^{d}\times \{1,2,\dots ,K\}} , where Y {\displaystyle Y} is the class label of X {\displaystyle X} . Assume that the conditional distribution of X, given that the label Y takes the value r is given by ( X ∣ Y = r ) ∼ P r {\displaystyle (X\mid Y=r)\sim P_{r}} for r = 1 , 2 , … , K {\displaystyle r=1,2,\dots ,K} where " ∼ {\displaystyle \sim } " means "is distributed as", and where P r {\displaystyle P_{r}} denotes a probability distribution. A classifier is a rule that assigns to an observation X=x a guess or estimate of what the unobserved label Y=r actually was. In theoretical terms, a classifier is a measurable function C: R d → { 1 , 2 , … , K } {\displaystyle C:\mathbb {R} ^{d}\to \{1,2,\dots ,K\}} , with the interpretation that C classifies the point x to the class C(x). |
Octagon Area Regular_octagon > Properties > Area The area can also be expressed as A = S 2 − a 2 , {\displaystyle \,\!A=S^{2}-a^{2},} where S is the span of the octagon, or the second-shortest diagonal; and a is the length of one of the sides, or bases. This is easily proven if one takes an octagon, draws a square around the outside (making sure that four of the eight sides overlap with the four sides of the square) and then takes the corner triangles (these are 45–45–90 triangles) and places them with right angles pointed inward, forming a square. The edges of this square are each the length of the base. |
Neodymium tantalate Properties Neodymium_tantalate > Properties Neodymium tantalate forms violet crystals of the monoclinic system, with space group I 2/a, cell parameters a = 0.55153 nm, b = 1.12388 nm, c = 0.51184 nm, β = 95.731°, Z = 4.There is a metastable high-pressure phase of the monoclinic system, space group P 21/c, cell parameters a = 0.75920 nm, b = 0.54673 nm, c = 0.77022 nm, β = 100.032°, Z = 4.Neodymium tantalate is insoluble in water. |
Specialty drugs High complexity Specialty_drugs > Definition and common characteristics > High complexity Therefore, it is necessary to use aseptic principles from initial manufacturing steps, which is also in contrast to most conventional drugs. Biological products often represent the cutting-edge of biomedical research and, in time, may offer the most effective means to treat a variety of medical illnesses and conditions that presently have no other treatments available." |
Solution (equation) Summary Root_of_an_equation The distinction between known variables and unknown variables is generally made in the statement of the problem, by phrases such as "an equation in x and y", or "solve for x and y", which indicate the unknowns, here x and y. However, it is common to reserve x, y, z, ... to denote the unknowns, and to use a, b, c, ... to denote the known variables, which are often called parameters. This is typically the case when considering polynomial equations, such as quadratic equations. However, for some problems, all variables may assume either role. |
Direction of propagation "Plane of vibration" Polarization_plane > History of the term > "Plane of vibration" The principle that refractive index depended on the density of the aether was essential to Fresnel's aether drag hypothesis. But it could not be extended to birefringent crystals — in which at least one refractive index varies with direction — because density is not directional. Hence his explanation of refraction required a directional variation in stiffness of the aether within a birefringent medium, plus a variation in density between media.James MacCullagh and Franz Ernst Neumann avoided this complication by supposing that a higher refractive index corresponded always to the same density but a greater elastic compliance (lower stiffness). |
Radix sorting Digit order Radix_sorting > Digit order LSD sorts are generally stable sorts. MSD radix sorts are most suitable for sorting strings or fixed-length integer representations. A sequence like would be sorted as . |
(CH3)2S Chemical reactions (CH3)2S > Chemical reactions For example, it serves a displaceable ligand in chloro(dimethyl sulfide)gold(I). Dimethyl sulfide is used in the workup of the ozonolysis of alkenes. It reduces the intermediate trioxolane. The Swern oxidation produces dimethyl sulfide by reduction of dimethylsulfoxide. With chlorinating agents such as sulfuryl chloride, dimethyl sulfide converts to chloromethyl methyl sulfide: SO2Cl2 + (CH3)2S → SO2 + HCl + ClCH2SCH3Like other methylthio compounds, DMS is deprotonated by butyl lithium: CH3CH2CH2CH2Li + (CH3)2S → CH3CH2CH2CH3 + LiCH2SCH3 |
Classical Mechanics (Goldstein) First edition Classical_Mechanics_(Goldstein) > Reception > First edition Quimby pointed out that although this book is suitable for students preparing for quantum mechanics, it is not helpful for those interested in analytical mechanics because its treatment omits too much. Quimby praised the quality of printing and binding which make the book attractive.In the Journal of the Franklin Institute, Rupen Eskergian noted that the first edition of Classical Mechanics offers a mature take on the subject using vector and tensor notations and with a welcome emphasis on variational methods. This book begins with a review of elementary concepts, then introduces the principle of virtual work, constraints, generalized coordinates, and Lagrangian mechanics. |
Impact wrench Effects of impact drive Impact_wrench > Effects of impact drive "Maximum torque" is the number most often given by manufacturers, which is the instantaneous peak torque delivered if the anvil is locked into a perfectly solid object. "Working torque" is a more realistic number for continually driving a very stiff fastener, and is typically measured by driving on a Skidmore-Wiheim torque tension test device for 5-10 seconds. "Nut-busting torque" is often quoted in impact tool specifications, with the usual definition being that the wrench can loosen a nut tightened with the specified amount of torque in some specified time period. |
Canonical correlation analysis Whitening and probabilistic canonical correlation analysis Canonical_correlation_analysis > Whitening and probabilistic canonical correlation analysis CCA can also be viewed as a special whitening transformation where the random vectors X {\displaystyle X} and Y {\displaystyle Y} are simultaneously transformed in such a way that the cross-correlation between the whitened vectors X C C A {\displaystyle X^{CCA}} and Y C C A {\displaystyle Y^{CCA}} is diagonal. The canonical correlations are then interpreted as regression coefficients linking X C C A {\displaystyle X^{CCA}} and Y C C A {\displaystyle Y^{CCA}} and may also be negative. The regression view of CCA also provides a way to construct a latent variable probabilistic generative model for CCA, with uncorrelated hidden variables representing shared and non-shared variability. |
Alphabetic numeral system Systems Alphabetic_numeral_system > Systems The Arabic abjad's 28 consonant signs could represent numbers up to 1000. Ancient Aramaic alphabets had enough letters to reach up to 9000. In mathematical and astronomical manuscripts, other methods were used to represent larger numbers. |
Magnesium deficiency Homeostasis Magnesium_deficiency > Pathophysiology > Homeostasis In the acute phase of magnesium deficiency there is an increase in absorption in the distal small intestine and tubular resorption in the kidneys. When this condition persists, serum magnesium drops and is corrected with magnesium from bone tissue. The level of intracellular magnesium is controlled through the reservoir in bone tissue. |
Periodic table of chemical elements Electron configurations Chemical_family > Atomic structures of the elements > Electron configurations The second shell similarly contains a 2s orbital, and it also contains three dumbbell-shaped 2p orbitals, and can thus fill up to eight electrons (2×1 + 2×3 = 8). The third shell contains one 3s orbital, three 3p orbitals, and five 3d orbitals, and thus has a capacity of 2×1 + 2×3 + 2×5 = 18. The fourth shell contains one 4s orbital, three 4p orbitals, five 4d orbitals, and seven 4f orbitals, thus leading to a capacity of 2×1 + 2×3 + 2×5 + 2×7 = 32. |
Epixenosomes Description Epixenosomes > Description Epixenosomes possess two distinct developmental phases linked to the host cell cycle. Stage I epixenosomes are spherical, 0.5 μm in diameter and are surrounded by two membranes. They divide by direct binary fission. Stage II epixenosomes are egg-shaped (2.2 μm in length and 1 μm in width) and show complex organization with different cytoplasmic compartments, more complicated than the majority of prokaryotic organisms. |
Coordination cage Classification Coordination_cage > Classification The twelve remaining edges are spanned with the edge ligands, Lp-Ph. Ligands are the building blocks of coordination cages, and the choice and ratio of ligands determine the final structure. Due to their highly symmetrical nature, coordination cages are also often referred to by their geometry. The geometry of high-symmetry cages is often that of Platonic or Archimedean solids; sometimes cages are casually referred to by their geometries.Of the named categories of coordination cages, cavitand cages and metalloprisms are some of the more common. |
Medical animation Pharmaceutical mechanism of action Medical_animation > Applications > Pharmaceutical mechanism of action As a way to explain how medications work, pharmaceutical manufacturers may provide mechanism of action animations, often through websites dedicated to specific prescription drugs. These medical visualizations typically do not represent cellular structures in a fully accurate or proportional way. Instead, mechanism of action animations may visually simplify the interaction between drug molecules and cells. These medical animations may also explain the physiological origins of the disease itself. |
Casino game Standard deviation Casino_game > House advantage > Standard deviation As the number of rounds increases, eventually, the expected loss will exceed the standard deviation, many times over. From the formula, we can see that the standard deviation is proportional to the square root of the number of rounds played, while the expected loss is proportional to the number of rounds played. As the number of rounds increases, the expected loss increases at a much faster rate. |
Relaxed sequential Summary Relaxed_sequential It is possible to design programs that require parallelism for correct behavior. Algorithms such as producer-consumer that are implemented so as to require two or more threads are one example of requiring concurrency to work properly. For instance, consider a bounded container with a capacity for only three items and a program which has one thread doing “PUT PUT PUT PUT,” and another thread doing “GET GET GET GET,” each doing their actions only four at a time. |
Osmotic coefficient Summary Osmotic_coefficient The osmotic coefficient based on molality m is defined by: and on a mole fraction basis by: where μ A ∗ {\displaystyle \mu _{A}^{*}} is the chemical potential of the pure solvent and μ A {\displaystyle \mu _{A}} is the chemical potential of the solvent in a solution, MA is its molar mass, xA its mole fraction, R the gas constant and T the temperature in Kelvin. The latter osmotic coefficient is sometimes called the rational osmotic coefficient. The values for the two definitions are different, but since the two definitions are similar, and in fact both approach 1 as the concentration goes to zero. |
Hibernation induction trigger Obligate hibernation Hibernation_induction_trigger > Mammals > Obligate hibernation Obligate hibernators are animals that spontaneously, and annually, enter hibernation regardless of ambient temperature and access to food. Obligate hibernators include many species of ground squirrels, other rodents, mouse lemurs, European hedgehogs and other insectivores, monotremes, and marsupials. These species undergo what has been traditionally called "hibernation": a physiological state wherein the body temperature drops to near ambient temperature, and heart and respiration rates slow drastically. |
Pythagorean school Geometry Pythagorean_doctrine > Philosophy > Geometry The Pythagoreans engaged with geometry as a liberal philosophy which served to establish principles and allowed theorems to be explored abstractly and rationally. Pythagorean philosophers believed that there was a close relationship between numbers and geometrical forms. Early-Pythagorean philosophers proved simple geometrical theorems, including "the sum of the angles of a triangle equals two right angles". Pythagoreans also came up with three of the five regular polyhedra: the tetrahedron, the cube and the dodecahedron. |
Ionosonde Ionogram Chirp_transmitter > Ionogram Data from ionograms may be used to measure changes in the Earth's ionosphere due to space weather events. Note that in the ionogram above the legend can be more clearly understood as having "Vx-" and "Vx+" to replace respectively "X-" and "X+". These refer to the vertical reflection of the eXtraordinary kind. |
Failure modes of electronics Contact failures Failure_modes_of_electronics > Contact failures Thermal expansion mismatch between the printed circuit board material and its packaging strains the part-to-board bonds; while leaded parts can absorb the strain by bending, leadless parts rely on the solder to absorb stresses. Thermal cycling may lead to fatigue cracking of the solder joints, especially with elastic solders; various approaches are used to mitigate such incidents. Loose particles, like bonding wire and weld flash, can form in the device cavity and migrate inside the packaging, causing often intermittent and shock-sensitive shorts. |
Pearson coefficient Reflective correlation coefficient Pearson_coefficient > Variants > Reflective correlation coefficient {\displaystyle \operatorname {corr} _{r}(X,Y)=\operatorname {corr} _{r}(Y,X)=\operatorname {corr} _{r}(X,bY)\neq \operatorname {corr} _{r}(X,a+bY),\quad a\neq 0,b>0.} The sample reflective correlation is equivalent to cosine similarity: r r x y = ∑ x i y i ( ∑ x i 2 ) ( ∑ y i 2 ) . {\displaystyle rr_{xy}={\frac {\sum x_{i}y_{i}}{\sqrt {(\sum x_{i}^{2})(\sum y_{i}^{2})}}}.} The weighted version of the sample reflective correlation is r r x y , w = ∑ w i x i y i ( ∑ w i x i 2 ) ( ∑ w i y i 2 ) . {\displaystyle rr_{xy,w}={\frac {\sum w_{i}x_{i}y_{i}}{\sqrt {(\sum w_{i}x_{i}^{2})(\sum w_{i}y_{i}^{2})}}}.} |
Token economy Specified target behaviors Token_economy > Basic requirements > Specified target behaviors Sometimes client manuals have specifications how many tokens can be earned by each target behavior. For instance, if making the bed is a target behavior, staff and clients have to know how a well-made bed looks like. However, often these specifications are hard to make: behavior such as eating politely and positive cooperation are hard to specify. |
Monatomic ideal gas Entropy Ideal_gas > Entropy This will mean that when the extensive parameters (V and N) are multiplied by a constant, the entropy will be multiplied by the same constant. Mathematically: S ( T , a V , a N ) = a S ( T , V , N ) . |
Torsion (mechanics) Summary Torsion_(mechanics) r is the perpendicular distance between the rotational axis and the farthest point in the section (at the outer surface). ℓ is the length of the object to or over which the torque is being applied. φ (phi) is the angle of twist in radians. G is the shear modulus, also called the modulus of rigidity, and is usually given in gigapascals (GPa), lbf/in2 (psi), or lbf/ft2 or in ISO units N/mm2. The product JTG is called the torsional rigidity wT. |
Organizational ergonomics Cognitive ergonomics Organizational_ergonomics > Domains of specialization > Cognitive ergonomics Cognitive ergonomics is concerned with mental processes, such as perception, emotion, memory, reasoning, and motor response, as they affect interactions among humans and other elements of a system. (Relevant topics include mental workload, decision-making, skilled performance, human reliability, work stress and training as these may relate to human–system and human–computer interaction design.) Epidemiological studies show a correlation between the time one spends sedentary and their cognitive function such as lowered mood and depression. |
Chronic wound Ischemia Chronic_wound > Pathophysiology > Ischemia Neutrophils remain in chronic wounds for longer than they do in acute wounds, and contribute to the fact that chronic wounds have higher levels of inflammatory cytokines and ROS. Since wound fluid from chronic wounds has an excess of proteases and ROS, the fluid itself can inhibit healing by inhibiting cell growth and breaking down growth factors and proteins in the ECM. This impaired healing response is considered uncoordinated. However, soluble mediators of the immune system (growth factors), cell-based therapies and therapeutic chemicals can propagate coordinated healing.It has been suggested that the three fundamental factors underlying chronic wound pathogenesis are cellular and systemic changes of aging, repeated bouts of ischemia-reperfusion injury, and bacterial colonization with resulting inflammatory host response. |
Optical correlation Filter design Optical_correlator > Filter design Many filters have been designed to be used with an optical correlator. Some have been proposed to address hardware limitations, others were developed to optimize a merit function or to be invariant under a certain transformation. |
Birnaviridae Viral Replication Birnaviridae > Viral Replication Viral replication is cytoplasmic. Entry into the host cell is achieved by cell receptor endocytosis. Replication follows the double-stranded RNA virus replication model in the cytoplasm. Double-stranded RNA virus transcription is the method of transcription in cytoplasm. |
Log point Definition Percent_error > Definition For example, we might want to calculate the relative change of −10 to −6. The above formula gives ((−6) − (−10)) / (−10) = 4 / −10 = −0.4, indicating a decrease, yet in fact the reading increased. Measures of relative difference are unitless numbers expressed as a fraction. Corresponding values of percent difference would be obtained by multiplying these values by 100 (and appending the % sign to indicate that the value is a percentage). |
Progeria Pathophysiology Progeria_syndrome > Pathophysiology When this shorter mRNA is translated into protein, it produces an abnormal variant of the prelamin A protein, referred to as progerin. Progerin's farnesyl group cannot be removed because the ZMPSTE24 cleavage site is lacking from progerin, so the abnormal protein is permanently attached to the nuclear rim. One result is that the nuclear lamina does not provide the nuclear envelope with enough structural support, causing it to take on an abnormal shape. |
Universal probability bound Dembski's estimate Universal_probability_bound > Dembski's estimate Hence, this value corresponds to an upper limit on the number of physical events that could possibly have occurred in the observable part of the universe since the Big Bang. Dembski has recently (as of 2005) refined his definition to be the inverse of the product of two different quantities: An upper bound on the computational resources of the universe in its entire history. This is estimated by Seth Lloyd as 10120 elementary logic operations on a register of 1090 bits The (variable) rank complexity of the event under consideration.If the latter quantity equals 10150, then the overall universal probability bound corresponds to the original value. |
Attribute hierarchy method Cognitive model representation Attribute_hierarchy_method > Cognitive model representation Attribute A1 is indirectly connected to attributes A5 to A9 through its connection with A4. The potential pool of items is represented by the incidence matrix (Q) matrix of order (k, p), where k is the number of attributes and p is number of potential items. This pool of items represents all combinations of the attributes when the attributes are independent of each other. |
Ibn al-Haytham Model of the Motions of Each of the Seven Planets Ibn_al-Haytham > Astronomical works > Model of the Motions of Each of the Seven Planets (There was also a second section on astronomical calculation, and a third section, on astronomical instruments.) Following on from his Doubts on Ptolemy, Alhazen described a new, geometry-based planetary model, describing the motions of the planets in terms of spherical geometry, infinitesimal geometry and trigonometry. He kept a geocentric universe and assumed that celestial motions are uniformly circular, which required the inclusion of epicycles to explain observed motion, but he managed to eliminate Ptolemy's equant. In general, his model didn't try to provide a causal explanation of the motions, but concentrated on providing a complete, geometric description that could explain observed motions without the contradictions inherent in Ptolemy's model. |
Infinite sequence Finite and infinite Mathematical_sequence > Formal definition and basic properties > Finite and infinite that has neither a first nor a final element—is called a bi-infinite sequence, two-way infinite sequence, or doubly infinite sequence. A function from the set Z of all integers into a set, such as for instance the sequence of all even integers ( ..., −4, −2, 0, 2, 4, 6, 8, ... ), is bi-infinite. This sequence could be denoted ( 2 n ) n = − ∞ ∞ {\displaystyle (2n)_{n=-\infty }^{\infty }} . |
Noncoding RNA Trans-acting Non-coding_RNAs > Biological roles > In gene regulation > Trans-acting In higher eukaryotes microRNAs regulate gene expression. A single miRNA can reduce the expression levels of hundreds of genes. The mechanism by which mature miRNA molecules act is through partial complementarity to one or more messenger RNA (mRNA) molecules, generally in 3' UTRs. The main function of miRNAs is to down-regulate gene expression. |
Computational epigenetics Epigenetic data processing and analysis Computational_epigenetics > Current research areas > Epigenetic data processing and analysis Various experimental techniques have been developed for genome-wide mapping of epigenetic information, the most widely used being ChIP-on-chip, ChIP-seq and bisulfite sequencing. All of these methods generate large amounts of data and require efficient ways of data processing and quality control by bioinformatic methods. |
Constantan Temperature measurement Constantan > Temperature measurement Constantan is also used to form thermocouples with wires made of iron, copper, or chromel. It has an extraordinarily strong negative Seebeck coefficient above 0 degrees Celsius, leading to a good temperature sensitivity. |
Oxo process Ruhrchemie/Rhone–Poulenc process Oxo_process > Processes > Ruhrchemie/Rhone–Poulenc process The Ruhrchemie/Rhone-Poulenc-process is the first commercially available two-phase system in which the catalyst is present in the aqueous phase. In the progress of the reaction an organic product phase is formed which is separated continuously by means of phase separation, wherein the aqueous catalyst phase remains in the reactor.The process is carried out in a stirred tank reactor where the olefin and the syngas are entained from the bottom of the reactor through the catalyst phase under intensive stirring. The resulting crude aldehyde phase is separated at the top from the aqueous phase. |
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