About observables in physics the use of the term observable in control theory Observability Cleanup date July 2010 No footnotes date May 2009 In physics , particularly in quantum physics , a system observable is a property of the Quantum state system state that can be determined by some sequence of physical operational definition operations . For example, these operations might involve submitting the system to various electromagnetic field s and eventually reading a value off some gauge. In systems governed by classical mechanics , any experiment ally observable value can be shown to be given by a real ... between system state and the value of an observable requires some basic linear algebra for its description ... meaningful observable. For the case of a system of Elementary particle particle s, the space V .... For example, suppose math a rangle math is an eigenket eigenvector of the observable math mathbf ... of the observable math scriptstyle mathbf A math is made while the system of interest is in the state .... To be more precise, the dynamical variable observable is a not necessarily bounded Hermitian operator .... In an infinite dimensional Hilbert space, the observable is represented by a Symmetric operator ... of an observable represents a real physical quantity for that particular dynamical variable, then we must conclude that there is no largest eigenvalue for the position observable in this uncountably ... Hilbert space, the role of an observable in quantum mechanics is to assign real numbers to outcomes of particular measurements this means that only certain measurements can determine the value of an observable ... to determine the value of an observable. Incompatibility of observables in quantum mechanics A crucial ... corresponding to non commutative operators are called incompatible . See also Observable universe ... Hilbert space. , www.am473.ca, 10 26 08 refend Category Quantum mechanics ca Observable cs Pozorovateln veli ina de Observable es Observable eo Videbla fiziko fr Observable it Osservabile hu Megfigyelhet ... more details
In mathematics , in the representation theory of algebraic group s, an observable subgroup is an algebraic subgroup of a linear algebraic group whose every finite dimensional rational representation arises as the restriction to the subgroup of a finite dimensional rational representation of the whole group. An equivalent formulation, in case the base field is closed, is that K is an observable subgroup of G if and only if the quotient variety G K is a quasi affine variety . Some basic facts about observable subgroups Every normal subgroup normal algebraic subgroup of an algebraic group is observable. Every observable subgroup of an observable subgroup is observable. External links http www.jstor.org cgi bin jstor printpage 00029327 di994362 99p00143 Extensions of Representations of algebraic linear groups Category Representation theory of algebraic groups ... more details
cleanup reorganize date October 2011 unreferenced date October 2011 A Partially Observable system is one in which the entire state of the system is not fully visible to an external sensor. In a partially observable system the observer may utilise a memory system in order to add information to the observer s understanding to the system. An example of a Partially Observable system would be a card game in which some of the cards are discarded into a pile face down. In this case the observer is only able to view their own cards and potentially those of the dealer. They are not able to view the face down used cards, and nor are they able to view the cards which will be dealt at some stage in the future. A memory system can be used to remember the previously dealt cards that are now on the used pile. This adds to the total sum of knowledge that the observer can use to make decisions. In contrast, a fully observable system would be that of chess. In chess apart from the who is moving next state the full state of the system is observable at any point in time. Partially Observable is a term used in a variety of mathematical settings, including that of Artificial Intelligence and Partially observable Markov decision process es. Category Systems science ... more details
In statistics , observable variables or manifest variables , as opposed to latent variable s, are those Variable mathematics variables that can be observed and directly measured. ref Dodge, Y. 2003 The Oxford Dictionary of Statistical Terms , OUP. ISBN 0 19 920613 9 ref See also Observables in physics Observability in control theory Latent variable model References references Category Social sciences Category Econometrics Category Statistical terminology Econometrics stub statistics stub ... more details
For a general discussion of the universe Universe File Observable Universe with Measurements 01.png thumb right 350px Visualization of the 93 billion light year or 28 billion parsec three dimensional observable ... small to be seen in the image. cosmology In Big Bang cosmology , the observable universe consists ... of the observable universe is roughly the same in every direction that is, the observable universe ... of the universe as a whole. Every location in the universe has its own observable universe which may or may not overlap with the one centered on the Earth. The word observable used in this sense does ... is made between the visible universe, which includes only signals emitted since recombination, and the observable ... the current comoving distance to the edge of the observable universe is calculated to be 14.3 billion ... 10.1071 AS03040 arxiv astro ph 0310808 bibcode 2004PASA...21...97D ref The diameter of the observable ... pages 27 ref putting the edge of the observable universe at about 46 47 billion light years ... American accessdate 2008 11 06 ref The universe versus the observable universe Some parts of the universe ... lie outside the observable universe. In the future the light from distant galaxies will have had more time to travel, so some regions not currently observable will become observable in the future. However ... visibility limit beyond which objects will never enter our observable universe at any time ... in the following paragraph is only larger than the number currently observable by a factor of 2.36 ... comoving radius of the observable universe is calculated on p. 7 to be 3.38 times the Hubble ..., so as shown on p. 8 the ratio between the number of galaxies observable in the future visibility limit to the number of galaxies observable today would be 4.50 3.38 sup 3 sup 2.36. ref Though in principle more galaxies will become observable in the future, in practice an increasing number ... subtlety is that a galaxy at a given comoving distance is defined to lie within the observable universe ... more details
The no observable adverse effect level NOAEL denotes the level of exposure of an organism , found by experiment or observation , at which there is no biologically or statistically statistical significance significant e.g. alteration of morphology biology morphology , functional capacity, Human development biology growth , development or life span increase in the frequency or severity of any adverse effects in the exposed population when compared to its appropriate control. ref http www.setonresourcecenter.com cfr 40CFR P132 003.htm Seton Resource Center ref ref http en.academic.ru dic.nsf enwiki 3597129 Definition of NOAEL ref In toxicology it is specifically the highest tested dose or concentration of a substance i.e. a drug or chemical or agent e.g. radiation , at which no such adverse effect is found in exposed test organisms where higher doses or concentrations resulted in an adverse effect. ref name Faustman Faustman, E.M., Omenn, G.S. Risk assessment. 2001 In C. D. Klaassen ed. Casarett & Doull s Toxicology, 6. ed., McGraw Hill, New York, pp. 92 94. ISBN 0 07 134721 6. ref ref http www.fsra.net glossary.html Food Safety and Risk Assessment website at Glasgow Caledonian University ref This level may be used in the process of establishing a dose response relationship , a fundamental step in most risk assessment methodologies. In drug development, NOAEL of a new drug is assessed in laboratory animals drugs prior to initiation of clinical trials to establish a safe clinical starting dose in human trials. The United States Environmental Protection Agency US EPA defines NOAEL as an exposure level at which there are no statistically or biologically significant increases in the frequency or severity of adverse effects between the exposed population and its appropriate control some effects may be produced at this level, but they are not considered as adverse, or as precursors ... level References references Category Toxicology de NOAEL fr Dose sans effet toxique observable it NOAEL ... more details
A Partially Observable Markov Decision Process POMDP is a generalization of a Markov Decision Process . A POMDP models an agent decision process in which it is assumed that the system dynamics are determined by an MDP, but the agent cannot directly observe the underlying state. Instead, it must maintain a probability distribution over the set of possible states, based on a set of observations and observation probabilities, and the underlying MDP. The POMDP framework is general enough to model a variety of real world sequential decision processes. Applications include robot navigation problems, machine maintenance, and planning under uncertainty in general. The framework originated in the Operations Research community, and was later taken over by the Artificial Intelligence and Automated planning Automated Planning communities. An exact solution to a POMDP yields the optimal action for each possible belief over the world states. The optimal action maximizes or minimizes the expected reward or cost of the agent over a possibly infinite horizon. The sequence of optimal actions is known as the optimal policy of the agent for interacting with its environment. Definition Formal definition A discrete time POMDP models the relationship between an agent and its environment. Formally, a POMDP ... and acting in partially observable stochastic domains journal Artificial Intelligence Journal volume ... control of partially observable Markov processes last Sondik first E.J. year 1971 publisher Stanford ... control of partially observable Markov decision processes over a finite horizon journal Operations ... title The optimal control of partially observable Markov processes over the infinite horizon discounted ... Persons with Dementia during Handwashing Using a Partially Observable Markov Decision Process author ... Using Video and a Partially Observable Markov Decision Process author Jesse Hoey, Pascal ... control fr Processus de d cision markovien partiellement observable zh ... more details
The Minor Planet Electronic Circulars MPECs are published by the Minor Planet Center . They generally contain Astrometry positional observations and Kepler orbit orbits of unusual minor planet s and all comet s. Monthly lists of observable unusual objects, observable distant objects, observable comets and the critical list of numbered minor planets also appear on these circulars. Daily Orbit Update MPECs, issued every day, contain new identifications and orbits of minor planets, obtained over the previous 24 hours. External links http www.minorplanetcenter.net iau services MPCServices.html MPC Publications http www.minorplanetcenter.net mpec RecentMPECs.html Recent MPECs See also Minor Planet Circular IAU Circular Electronic Telegram of the Central Bureau for Astronomical Telegrams sci mag stub Category Astronomy data and publications Category Science and technology magazines ... more details
Context date September 2009 Representation validity is concerned about how well the constructs or abstraction s translate into observable measures. There are two primary questions to be answered Do the sub constructs properly define the construct if you break up the main abstractions into smaller abstractions or definitions ? Do the observation s properly interpret, measure, or test the constructs? One way to argue positively, albeit a very weak argument, is to claim face validity for the construct observable relationship. Basically this is making the following claim on the face of it, it seems like a good translation. The weakness of this argument can be strengthened by a consensus of experts. Another way to argue positively is to claim content validity for the construct observable relationship. To do this one must check the operationalization against the relevant content domain for the construct to extent to which the tests i.e., the observable measures measure the content of the subject being tested i.e., that all the important content areas are covered adequately. Category Validity statistics psychology stub sociology stub statistics stub ... more details
The Observability Gramian is a Gramian used in optimal control theory to determine whether or not a linear system is observable. For a linear system described by math dot x A x B u math math y C x D u , math The observability Gramian is given by math W o t int limits 0 t e A T tau C T C e A tau d tau math If and only if the matrix math W o math is nonsingular for every math t 0 math , the pair math A,C math is observable. See also Controllability Gramian Gramian matrix References unreferenced date July 2008 Category Control theory math stub ... more details
Dynamic psychiatry is that which is based on the study of emotional processes , their origins, and the mental mechanisms underlying them, rather than observable behavioral phenomena, in contrast with descriptive psychiatry which is based on the study of observable symptoms and behavioral phenomena rather than underlying psychodynamic processes. Most modern psychiatrists believe that it is most helpful to combine the two complementary approaches in a biopsychosocial model . ref name isbn0 415 25670 4 cite book author Williams, Gavin De Kadt, Emanuel Jehuda title Sociology and development publisher Routledge location New York year 2001 pages 152 isbn 0 415 25670 4 ref References reflist Category Psychiatric models psych stub ... more details
orphan date May 2010 Process tracing is a method used to evaluate and develop theories in political science . ref http ideas.repec.org a eee jobhdp v43y1989i1p75 117.html ref The method works by extracting all of the observable implications of a theory, rather than merely the observable implications regarding the dependent variable . Once these observable implications are extracted particularly with reference to the microfoundations of how a theory s independent variable causes the predicated change in the dependent variable they are then tested empirically, often through the method of elite interviews but also often through other rigorous forms of data analysis . ref Designing Social Inquiry , Gary King, Robert O Keohane, Sidney Verba ref It is often used to complement comparative case study methods. By tracing the causal process from the independent variable of interest to the dependent variable, it may be possible to rule out potentially intervening variable s in imperfectly matched cases. This can create a stronger basis for attributing causal significance to the remaining independent variables. ref Alexander L. George and Bennett, Andrew. 2005 . Case studies and theory development in the social sciences . London, MIT Press 2005. ISBN 0 262 57222 2, pages 214 15 ref References Reflist DEFAULTSORT Process Tracing Category Political science ... more details
Unreferenced stub auto yes date December 2009 A hydrological phenomenon , or hydrologic phenomenon , is an observable movement of water within the water cycle . Hydrological phenomena are studied within the field of hydrology , and include precipitation meteorology precipitation , including rain and snow flood s drought s DEFAULTSORT Hydrological Phenomenon Category Hydrology Category Soil physics geomorph stub ... more details
Cosmic mass may mean mass of the cosmos , see Mass of the observable universe Cosmic mass distribution , see Cosmic microwave background radiation and Large scale structure of the cosmos Cosmic mass density , see Shape of the Universe Cosmic mass field , see Metric expansion of space Cosmic mass function , see Friedmann equations Techno Cosmic Mass , a religious and musical event, promoted by Matthew Fox priest Techno Cosmic Mass Matthew Fox dab ... more details
In mathematics , in the representation theory of algebraic group algebraic Group mathematics groups , a Grosshans subgroup , named after Frank Grosshans , is an algebraic subgroup of an algebraic group that is an observable subgroup for which the ring mathematics ring of functions on the quotient algebraic variety variety is finitely generated . External links http www.staff.uni mainz.de pommeren Artikel invar.pdf Invariants of Unipotent subgroups http www.math.lsa.umich.edu idolga invbook.pdf Lectures on Invariant Theory Category Representation theory of algebraic groups algebra stub ... more details
MMG may refer to Mechanomyogram or mechanomyography , measuring the mechanical signal observable from the surface of a muscle when the muscle is contracted Medium machine gun , a category of firearm Minerals and Metals Group , an Australia based mining company Mosley Music Group , a record label created by Timbaland Motor City Machine Guns , a professional wrestling tag team often abbreviated MMG Maybach Music Group , record label founded by Rick Ro Rick Ross disambig de MMG it MMG ja MMG ru ... more details
Mergeto Pulsar date April 2010 Timing noise is the name for rotational irregularities observed in all pulsars . This timing noise is observable as random wandering in the pulse frequency or phase. ref http www.saao.ac.za wgssa as4 urama.html African Skies 4 Radio Pulsar Glitch Studies Bot generated title ref It is unknown whether timing noise is related to pulsar Glitch astronomy glitches . References references var star stub physics stub Category Pulsars ... more details
Business event can refer to A phenomenon , any observable occurrence, or an extraordinary occurrence, that has significance to a business. A type of gathering A convention meeting , for example, a sales convention A Users group meeting In technology Event computing , a software message indicating that something has happened, such as a keystroke or mouse click Event UML , in Unified Modeling Language, a notable occurrence at a particular point in time Complex event processing where events that have significance to the business may be deemed Business Events. disambiguation ... more details
learning , and can be solved with value iteration and related methods. Partially observable Markov decision process A POMDP partially observable Markov decision process POMDP is a Markov decision ... more details
about the use of this term in Hinduism and Buddhism Trail kya the Maoist concept Three Worlds Theory Artwork image file Three Worlds.jpg title Three Worlds artist M. C. Escher year 1955 type Lithography lithograph height 36.2 width 24.7 Italic title Three Worlds is a Lithography lithograph print by the Netherlands Dutch artist M. C. Escher which was first printed in December, 1955. Three Worlds depicts a large pool or lake during the autumn or winter months, the title referring to the three visible perspectives in the picture the surface of the water on which leaf leaves Bouyancy float , the world above the surface, observable by the water s mirror reflection of a forest , and the world below the surface, observable in the large fish swimming just below the water s surface. Escher also created a picture named Two Worlds . See also Puddle M. C. Escher Puddle Printmaking Sources Locher, J.L. 2000 . The Magic of M. C. Escher . Harry N. Abrams, Inc. ISBN 0 8109 6720 0. External links http home.comcast.net eschermc Gallery of Eschers images M. C. Escher Category Works by M. C. Escher Category 1955 works printmaking stub ... more details
Orphan date February 2009 Shallow sky is a term sometimes used by amateur astronomers, as the opposite to deep sky . The shallow sky is space within our solar system, plus our own atmosphere. Sky phenomena such as Astronomical conjunction planetary conjunctions , solar eclipse s, lunar eclipse s, as well as atmospheric phenomena like halo optical phenomenon halo es, rainbow s, and noctilucent clouds , are all occurring in the shallow sky. The Shallow Sky Bulletin ISSN 0897 2532 was published by Stephen M. Smith from 1986 through 2000. Mr. Smith operated The Comet Rapid Announcement Service CRAS to disseminate notices about newly discovered bright comets, news about comets and daily positions ephemerides for observable comets. The common practice for publishing comet tables was to display positions at 10 day intervals. All of the comet position tables published in SSB were at 1 day intervals. During the 14 year run of SSB , CRAS subscribers were informed about all observable comets. In the 2006 Apr. 13 issue of The Minor Planet Circulars Minor Planets and Comets , published by http www.cfa.harvard.edu iau mpc.html The Minor Planet Center of the Smithsonian Astrophysical Observatory, Mr. Smith s work was honored by the naming of minor planet 9891 Stephensmith. Category Observational astronomy astronomy stub ... more details
Unreferenced stub auto yes date December 2009 Lowercase In science , e folding is the time interval in which an exponential growth exponentially growing quantity increases by a factor of e mathematical constant e . This term is often used in theoretical physics , especially when cosmic inflation is investigated. Physicists often talk about the e folding time scale that is determined by the proper time in which the length of a patch of space or spacetime increases by the factor e mentioned above. In finance the logarithmic return or continuous compounding continuously compounded return , also known as Compound interest Force of interest force of interest , is the reciprocal of the e folding time. The term e folding time is also sometimes used similarly in the case of exponential decay , to refer to the timescale for a quantity to decrease to 1 e of its previous value. The process of evolving to equilibrium is often characterized by a time scale called the e folding time, . This time is used for processes which evolve exponentially toward a final state equilibrium . In other words if we examine an observable, X, associated with a system, temperature or density for example then after a time, , the initial difference between the initial value of the observable and the equilibrium value, Xi, will have decreased to Xi e where the number E mathematical constant e 2.71828 . DEFAULTSORT E Folding Category Cosmic inflation Phys stub ... more details
Context date October 2009 notability date March 2011 In computer science , a predictive state representation PSR is a dynamical system representation that keeps track of the state of the system using predictions of future observations. A PSR s state is grounded directly to statistics over observable quantities. This is in contrast to other models of dynamical systems, such as partially observable Markov decision process es POMDPs where the state of the system is represented as a probability distribution over unobserved nominal states. References cite conference last Littman first Michael L. authorlink Michael L. Littman coauthors Richard S. Sutton Satinder Singh title Predictive Representations of State booktitle Advances in Neural Information Processing Systems 14 NIPS pages 1555 1561 year 2002 url http www.eecs.umich.edu baveja Papers psr.pdf cite conference last Singh first Satinder coauthors Michael R. James Matthew R. Rudary title Predictive State Representations A New Theory for Modeling Dynamical Systems booktitle Uncertainty in Artificial Intelligence Proceedings of the Twentieth Conference UAI pages 512 519 year 2004 url http www.eecs.umich.edu baveja Papers uai2004psr.pdf Category Machine learning Category Dynamical systems Compu AI stub ... more details
In control theory , given any transfer function , any state space controls state space model that is both controllability controllable and observability observable and has the same input output behaviour as the transfer function is said to be a minimal realization of the transfer function . The realization is called minimal because it describes the system with the minimum number of states. The minimum number of state variables required to describe a system equals the order of the differential equation more state variables than the minimum can be defined. For example, a second order system can be defined by two minimal realization or more state variables. math stub Category Control theory pl Model minimalny ... more details
Unreferenced stub auto yes date December 2009 Image Tekiyeh amir chaghmagh yazd.jpg thumb right The medieval Tekyeh Amir Chakhmagh , Yazd , Iran . A Tekyeh is a place where Shia s gather to mourn the killing of Husayn bin Ali . Such places are particularly found in Iran . They are usually traditionally designed with observable elements of Persian architecture . Tehran is said to have had up to 50 Tekyehs in the Qajar dynasty Qajar era. Iranian Architecture Category Iranian architecture Islam stub Iran stub de Tekiyeh fa fr Tekiyeh ... more details
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