Weasel date June 2010 A stochasticcontextfreegrammar SCFG also probabilistic contextfreegrammar , PCFG is a contextfreegrammar in which each production is augmented with a probability. The probability of a derivation parse is then the product of the probabilities of the productions used in that derivation thus some derivations are more consistent with the stochasticgrammar than others. SCFGs extend contextfree grammars in the same way that hidden Markov model s extend regular grammar s. SCFGs ... StochasticContextFreeGrammar Category Bioinformatics Category Formal languages Category Natural .... SCFGs are a specialized form of weighted contextfreegrammar s. Techniques A variant of the CYK ... pairing can be represented in a contextfreegrammar the major exception being pseudoknot s . For example, consider the following grammar, where a,c,g,u represents nucleotides and S is the start symbol ... language processing Contextfree grammars were originally conceived in an attempt to model natural .... As such, a probabilistic grammar s validity is constrained by context of the text used to train it the definition of most likely is likely to vary with the context of discourse. An example of a probabilistic ... xpl freeabs all.jsp?arnumber 1566496 ref RNA Contextfree grammars are adept at modeling the secondary ... a measure of how consistent the sequence is with the given grammar. The Inside outside algorithm ... upgrading the grammar. One may construct a probabilistic grammar from a traditional formal syntax ... approaching the accuracies of PCFG . Here is a tiny example of a 2 rule PCFG grammar. Each rule ... 0.3 VP V NP NP Given this grammar, we can now say that the number of NPs expected while deriving VPs ... a non probabilistic grammar into large vocabulary continuous speech recognition journal IEEE Workshop ... of grammar, including a complete conceptual lexicon in certain versions, were hardwired from ... for relative clause s . Probabilistic versions of Minimalist grammar Minimalist Grammars have ... more details
A weighted contextfreegrammar WCFG is a contextfreegrammar where each production has a numeric weight associated with it. The weight of a parse tree in a WCFG is the weight of the rule used to produce the top node, plus the weights of its children. A special case of WCFGs are stochasticcontextfreegrammar s, where the weights are logarithm s of probability probabilities . An extended version of the CYK algorithm can be used to find the lightest least weight derivation of a string given some WCFG. comp sci theory stub Category Formal languages hr Te inska kontekstno neovisna gramatika ja ru ... more details
Synchronous contextfree grammars SynCFG or SCFG not to be confused with Stochasticcontextfreegrammarstochastic CFGs constitute a formal model of natural language syntax , developed in the area of statistical machine translation MT . The theory of SynCFGs borrows from syntax directed transduction and syntax based machine translation , modeling the reordering of clauses that occurs when translating a sentence by correspondences between phrase structure rules in the source and target languages. Performance of SCFG based MT systems has been found comparable with, or even better than, state of the art phrase based machine translation systems. ref name Chiang cite journal last1 Chiang first1 David year 2007 title Hierarchical phrase based translation journal Computational Linguistics journal Computational Linguistics volume 33 number 2 pages 201 228 ref Several algorithms exist to perform translation using SynCFGs. ref cite conference last1 Venugopal first1 Ashish last2 Zollmann first2 Andreas last3 Vogel first3 Stephan year 2007 title An efficient two pass approach to Synchronous CFG driven statistical MT booktitle Proc. NAACL HLT pages 500 507 ref Formalism Rules in a SynCFG are superficially similar to CFG rules, except that they specify the structure of two phrases at the same time one in the source language the language being translated and one in the target language. Numeric indices indicate correspondences between non terminals in both constituent trees. Chiang ref name Chiang gives the Chinese English example math X to math yu math X 1 math you math X 2 math , have math X 2 math with math X 1 math Software http cdec decoder.org cdec , MT decoding package that supports SynCFGs References references Category Formal languages Category Machine translation Category Natural language parsing Category Statistical natural language processing ... more details
contextfree. ref name pullum gazdar1982 See also Parsing expression grammarStochasticcontext ...refimprove date February 2012 In formal language theory , a contextfreegrammar CFG is a formal grammar ... use the term phrase structure grammar to refer to contextfree grammars, whereby phrase structure grammars ... . A contextfreegrammar provides a simple and mathematically precise mechanism for describing the methods ... and reference are not part of the contextfreegrammar, but the basic recursive structure of sentences ... project 1957 1960 , which, as a consequence, also featured a contextfreegrammar to describe the resulting ... identified with contextfreegrammar rules, especially in computer science. Formal constraints .... Formal definitions A contextfreegrammar G is defined by the 4 tuple ref The notation here ... u k Rightarrow v math Contextfree language The language of a grammar math G V ,, Sigma ,, R ,, S , math ... . Proper CFGs A contextfreegrammar is said to be proper , if it has no inaccessible symbols math .... Examples Well formed parentheses The canonical example of a contextfreegrammar is parenthesis ... can be derived in that grammar However, there is no contextfreegrammar for generating all sequences ... grammar is contextfree, however not all contextfree grammars are regular. It is common to list ... In a contextfreegrammar, we can pair up characters the way we do with bracket s. The simplest ... the empty string while the original grammar did not. Algebraic expressions Here is a contextfree ... rules. Further examples Example 1 A contextfreegrammar for the language consisting of all strings ... contextfreegrammar S &rarr bSbb A A &rarr aA &epsilon Other examples The First order logic Formation ... forms Every contextfreegrammar that does not generate the empty string can be transformed into one ... math , but there need be no other rule. Every contextfreegrammar with no production has ..., given a contextfreegrammar, one can use the Chomsky Normal Form to construct a polynomial ... more details
Generalized ContextfreeGrammar GCFG is a grammar formalism that expands on contextfree grammars by adding potentially non contextfree composition functions to rewrite rules. ref name weir1988 Weir, David H. 1988. Characterizing mildly context sensitive grammar formalisms. Dissertation, U Penn. ref Head grammar and its weak equivalents is an instance of such a GCFG which is known to be especially adept at handling a wide variety of non CF properties of natural language. Description A GCFG consists of two components a set of composition functions that combine string tuples, and a set of rewrite rules. The composition functions all have the form math f langle x 1, ..., x m rangle, langle y 1, ..., y n rangle, ... gamma math , where math gamma math is either a single string tuple, or some use of a potentially different composition function which reduces to a string tuple. Rewrite rules look like math X to f Y, Z, ... math , where math Y math , math Z math , ... are string tuples or non terminal symbols. The rewrite semantics of GCFGs is fairly straight forward. An occurrence of a non terminal symbol is rewritten using rewrite rules as in a contextfreegrammar, eventually yielding just compositions composition functions applied to string tuples or other compositions . The composition ... A simple translation of a contextfreegrammar into a GCFG can be performed in the following fashion. Given the grammar in 1 , which generates the palindrome language math ww R w in a, b math , where ... Generalized ContextFreeGrammar Category Formal languages Category Grammar frameworks ... rangle, langle a rangle math math langle abbbba rangle math Linear Contextfree Rewriting Systems LCFRSs ... f x g x, y math or math f x, y g x math . A grammar in which all composition functions are both linear and regular is called a Linear Contextfree Rewriting System LCFRS , a subset of the GCFGs with strictly ... Tree adjoining grammar s. Head grammar is an example of an LCFRS that is strictly less powerful ... more details
In formal grammar theory, the deterministic contextfree grammars DCFGs are a proper subset of the contextfree grammars . The deterministic contextfree grammars are those a deterministic pushdown automaton can recognize. A DCFG is the finite set of rules defining the set of well formed expressions in some deterministic contextfree language . History In the 1960s, theoretic research in computer science on regular expressions and finite automata led to the discovery that contextfree grammars are equivalent to pushdown automata . These grammars were thought to capture the syntax of computer programming languages. The first computer programming languages were under development at the time see History of programming languages and writing compilers was difficult. But using contextfree grammars to help automate the parsing part of the compiler simplified the task. Deterministic contextfree grammars were particularly useful because they could be parsed sequentially, which was a requirement due to computer memory constraints. ref cite book editors A Salomaa & D Wood & S Yu title A Half Century of Automata Theory year 2001 publisher World Scientific Publishing Co. Pte. Ltd pages 38 39 ref Uses LALR parsers, which use a subset of DCFGs, have practical value as program code validators. Given the formal rules of a DCFG, these parsers efficiently ensure a program can be generated from those rules. In fact, this syntax validation is one of the operations a compiler performs. need to state the two restrictions for determinism, can t figure out how to express it simply Limitations Since DCFGs are a proper subset of CFGs, they are of less descriptive power than some CFGs. See also Deterministic parsing LR parser LL parser References references Formal languages and grammars Category Formal languages cs Deterministick bezkontextov gramatika hr Deterministi ka kontekstno neovisna gramatika sr zh ... more details
Contextfree may refer to Concepts contextfreegrammar deterministic contextfreegrammarstochasticcontextfreegrammar weighted contextfreegrammarcontextfree language Software ContextFree , a computer language for contextfree grammars disambig ... more details
A stochasticgrammar statistical grammar is a grammar framework with a probabilistic notion of grammaticality Stochasticcontextfreegrammar Statistical parsing Data oriented parsing Hidden Markov model Estimation theory Statistical natural language processing uses stochastic , probabilistic and statistical methods, especially to resolve difficulties that arise because longer sentences are highly ambiguous when processed with realistic grammars, yielding thousands or millions of possible analyses. Methods for disambiguation often involve the use of corpus linguistics corpora and Markov model s. A probabilistic model consists of a non probabilistic model plus some numerical quantities it is not true that probabilistic models are inherently simpler or less structural than non probabilistic models. ref John Goldsmith. 2002. Probabilistic Models of Grammar Phonology as Information Minimization. Phonological Studies 5 21&ndash 46. ref The technology for statistical NLP comes mainly from machine learning and data mining , both of which are fields of artificial intelligence that involve learning from data. See also Colorless green ideas sleep furiously Computational linguistics Refimprove date March 2011 More footnotes date March 2011 References references Further reading Christopher D. Manning, Hinrich Sch tze Foundations of Statistical Natural Language Processing , MIT Press 1999 , ISBN 978 0262133609. Stefan Wermter, Ellen Riloff, Gabriele Scheler eds. Connectionist, Statistical and Symbolic Approaches to Learning for Natural Language Processing , Springer 1996 , ISBN 978 3540609254. Category Grammar frameworks Category Statistical natural language processing Category Probabilistic models ling stub nl Stochastische grammatica ... more details
be replaced with or not. This is different from a contextfreegrammar where the context of a nonterminal is not taken into consideration. Indeed, every production of a contextfreegrammar is of the form ...A context sensitive grammar CSG is a formal grammar in which the left hand sides and right hand sides of any production rules may be surrounded by a context of terminal symbol terminal and nonterminal symbol s. Context sensitive grammars are more general than contextfreegrammar s but still orderly enough to be parsing parsed by a linear bounded automaton . The concept of context sensitive grammar ... upon the context. A formal language that can be described by a context sensitive grammar is called a context sensitive language . Formal definition A formal grammar G N , , P , S this is the same as G ... that for any production rule of the form u v of a context sensitive grammar, it shall be true that u ... are a proper superset of the contextfree languages, rather than having to make the weaker statement that all contextfree grammars with no productions are also context sensitive grammars. The name ... in these two definitions are identical. Examples This grammar generates the canonical non context ... 1 math , and other languages with even more letters. The following grammar generates the non context ... forms Every context sensitive grammar which does not generate the empty string can be transformed into an equivalent ... s belongs to the language of a certain context sensitive grammar G , is PSPACE complete . There are even some context sensitive grammars whose fixed grammar recognition problem is PSPACE complete. The emptiness problem for context sensitive grammars given a context sensitive grammar G, is math L ... are feasible, such as tree adjoining grammar s, combinatory categorial grammar s, coupled contextfree language s, and linear contextfree rewriting system s. The languages generated by these formalisms properly lie between the contextfree and context sensitive languages. See also Chomsky hierarchy ... more details
are Undecidable language undecidable for arbitrary contextfreegrammar s A and B Equivalence is math L A L B math ? is math L A cap L B emptyset math ? However, the intersection of a contextfree language and a regular language is contextfree, so if math B math were a regular language, this problem .... See also Pushdown automata Contextfreegrammar Deterministic contextfree language Parsing ...In formal language theory , a contextfree language is a formal language language generated by some contextfreegrammar . The set of all contextfree languages is identical to the set of languages accepted by pushdown automaton pushdown automata . Examples An archetypical contextfree language is math ... . Also, most arithmetic expressions are generated by contextfree grammars. Closure properties Context ... are contextfree languages, the following languages are contextfree as well the union set theory ... math vu uv in L math Contextfree languages are not closed under complement complexity complement ... . However, if L is a contextfree language and D is a regular language then both their intersection math L cap D math and their difference math L setminus D math are contextfree languages. Nonclosure under intersection and complement The contextfree languages are not closed under intersection. This can ... mid m,n geq 0 math , which are both contextfree. Their intersection is math A cap B a n b n c n mid n geq 0 math , which can be shown to be non contextfree by the pumping lemma for contextfree languages . Contextfree languages are also not closed under complementation, as for any languages A and B ... are decidable for arbitrary contextfree languages is math L A emptyset math ? is math L A math ... free languages The reverse of a contextfree language is contextfree, but the complement need not be. Every regular language is contextfree because it can be described by a contextfreegrammar . The intersection of a contextfree language and a regular language is always contextfree. There exist ... more details
. The deterministic contextfree languages are exactly those recognized by some LR grammar . ref ...A deterministic contextfree language is a formal language which is defined by a deterministic contextfreegrammar . ref cite book last John Hopcroft Hopcroft first John coauthors Jeffrey Ullman title Introduction to automata theory, languages, and computation year 1979 publisher Addison Wesley page 233 ref The set of deterministic contextfree languages is called DCFL ref CZoo Class DCFL D dcfl ref and is identical to the set of languages accepted by a deterministic pushdown automaton . The set of deterministic contextfree languages is a proper subset of the set of contextfree language s that possess an unambiguous contextfreegrammar . For example, the language of even length palindrome s on the alphabet of 0 and 1 has the simple, unambiguous grammar S 0S0 1S1 , but it cannot be parser parsed by a deterministic push down automaton. ref cite book last John Hopcroft Hopcroft first John coauthors Rajeev Motwani & Jeffrey Ullman title Introduction to automata theory, languages, and computation 2nd edition year 2001 publisher Addison Wesley pages 249 253 ref The languages of this class have practical importance in computer science. The complexity of the program and execution of a deterministic pushdown automaton is vastly less than that of a nondeterministic one. In the naive implementation, it must make copies of the stack every time a nondeterministic step occurs. The best known algorithm to test membership in any contextfree language is CYK algorithm Extensions Valiant s algorithm , taking O n sup 2.378 sup time, whereas membership in a deterministic contextfree language can be tested in O n time, ref cite book last Harrison first Michael A. title Introduction to Formal ... contextfree languages can be recognized by a deterministic Turing machine in polynomial ... s Greibach s theorem proves that it is undecidable whether a given contextfree language is deterministic ... more details
orphan date September 2011 FreeGrammar Schools were schools which usually operated under the jurisdiction of the church in England in the Middle Ages pre modern England . Education had long been associated with religious institutions since a Cathedral grammar school was established at Canterbury under the authority of Augustine of Canterbury St Augustine s church and thelberht of Kent King Ethelbert at the end of the sixth century. ref A.F. Leach, The Schools of Medieval England London, 1915 , p.3 ref The religious reforms of Henry VIII and the influence of renaissance philosophy resulted in an increased educational drive and a broadening of curriculum , but perhaps the most significant change of this period was that many new Grammar school grammar schools were private institutions supervised in variable degree by church and state . ref Raymond Williams, The Long Revolution , London, Chatto and Windass, 1976 , p. 132 ref From the sixteenth century, there was much lively debate over curriculum, arguments about the original intentions of original benefactors and administrative detail. Due to the religious influence of FreeGrammar School benefactors, these disputes or disciplinary concerns were often fought in church courts , and the consequent records offer rich detail of these concerns. References reflist Category History of education in England ... more details
Multiple issues unreferenced February 2011 incomplete February 2011 Infobox UK school name Mirfield FreeGrammar and Sixth Form image size latitude longitude dms motto motto pl established 1667 approx closed c approx type Academy English school Academy religion president head label Headteacher head Mrs L Barker r head label r head chair label chair founder founder pl specialist specialist pl street Kitson Hill Road city Mirfield county West Yorkshire country England postcode LEA ofsted urn staff enrollment gender Mixed lower age 11 upper age 18 including sixth form houses colours publication free label 1 free 1 free label 2 free 2 free label 3 free 3 website http www.themfg.co.uk website name The Mirfield FreeGrammar also known as the MFG and Sixth Form is a secondary school in the town of Mirfield , West Yorkshire. Patrick Stewart Sir Patrick Stewart went to the MFG, In September 2011 he opened the School as an Academy English school academy . The School is rated Outstanding by Ofsted. coord missing West Yorkshire DEFAULTSORT Mirfield FreeGrammar Category Academies in Kirklees Category Educational institutions established in the 1660s Yorkshire school stub ... more details
Cleanup date July 2009 The pumping lemma for contextfree languages , also known as the Yehoshua Bar Hillel Bar Hillel lemma , is a lemma mathematics lemma that gives a property shared by all contextfree language s. Formal statement If a language L is contextfree, then there exists some integer p 1 ... for every integer n 0. Informal statement and explanation The pumping lemma for contextfree languages called just the pumping lemma for the rest of this article describes a property that all contextfree languages are guaranteed to have. The property is a property of all strings in the language ... contextfree languages. Say s is a string of length at least p that is in the language. The pumping ... used to prove that a given language is non contextfree by showing that for each p , we can find ... The pumping lemma for contextfree languages can be used to show that certain languages are not contextfree. For example, we can show that language math L lbrace a ib ic i i 0 rbrace math is not contextfree by using the pumping lemma in a proof by contradiction . First, assume that math L math is contextfree. By the pumping lemma, there exists an integer math p math which is the pumping ... that math L math is contextfree must be false. While the pumping lemma is often a useful tool to prove that a given language is not contextfree, it does not give a complete characterization of the contextfree languages. If a language does not satisfy the condition given by the pumping lemma, we have established that it is not contextfree. On the other hand, there are languages that are not context ... of the contextfree languages. See also Pumping lemma for regular languages Formal languages ... 2.3 Non contextfree Languages, pp. 115&ndash 119. DEFAULTSORT Pumping Lemma For ContextFree Languages ... gives the pumping lemma its name. Note that finite language s which are regular and hence contextfree obey the pumping lemma trivially by having p equal to the maximum string length in L plus one ... more details
Primary sources date March 2008 Infobox UK school name Newport FreeGrammar School image size latitude 51.990558 longitude 0.213817 dms dms motto Suffer and Serve motto pl established 1588 approx closed c approx type Comprehensive school Comprehensive religion president head label Headteacher head Mr Se n O Hagan r head label r head chair label chair founder founder pl specialist Language College Language specialist pl y street Bury Water Lane city Newport, Essex Newport county Essex country England postcode CB11 3TR LEA Essex ofsted yes urn 115352 staff enrollment approx. 852 gender mixed sex education Mixed lower age 11 upper age 18 houses houses color box green Frankland color box silver Caius br color box gold Saxie color box red Banstead br color box purple Morden color box royalblue Trappes colours publication free label 1 free 1 free label 2 free 2 free label 3 free 3 website http www.nfgs.essex.sch.uk website name Newport FreeGrammar School , in Newport, Essex Newport , Essex , England was founded in 1588. ref cite web url http www.nfgs.essex.sch.uk tradition.html title Tradition to Technology accessdate 2007 01 11 publisher Newport FreeGrammar School archiveurl http web.archive.org web 20061009140720 http www.nfgs.essex.sch.uk tradition.html Bot retrieved archive archivedate 2006 10 09 ref The school is a mixed sex education mixed comprehensive school with a sixth form . It previously existed in different forms including a boarding school and a grammar school . The Headteacher is Mr Se n O Hagan and the Deputy headteachers are Kay Turner, Matthew Gibson and Mike Hodgkiss. There are about 852 students, including 194 in the sixth form. ref cite web url http www.nfgs.essex.sch.uk apps nfgssite title Newport ... the positive choice publisher Newport FreeGrammar School ... on a four point scale. They said blockquote Newport FreeGrammar is a good school which provides good ... school 115 s5 115352 20060424.pdf Newport FreeGrammar School Inspection Report , Office for Standards ... more details
refimprove date June 2007 Cleanup date September 2010 Wiktionary stochasticStochastic from the Greek ..., sporadic and categorically NOT intermittent. A stochastic process is one whose behavior is non ... which is analyzable in terms of probability deserves the name of stochastic process . Mathematical theory The use of the term stochastic to mean based on the theory of probability has been traced ... , specifically in probability theory , the field of stochastic process es has been a major area of research. A stochastic matrix is a matrix mathematics matrix that has non negative real number real entries that sum to one in each column. Artificial intelligence In artificial intelligence , stochastic programs work by using probabilistic methods to solve problems, as in simulated annealing , stochastic neural network s, stochastic optimization , genetic algorithms , and genetic programming . A problem itself may be stochastic as well, as in planning under uncertainty. Natural science An example of a stochastic process in the natural world is pressure in a gas as modeled by the Wiener process ... will exhibit stochastic characteristics, such as filling the container, exerting equal pressure ... generally considered forms of stochastic simulation can be arguably traced back to the earliest ... of random numbers which had been previously used for statistical sampling. Biology Stochastic resonance In biological systems, introducing stochastic noise has been found to help improve the signal strength ... lend themselves to stochastic analysis. Gene expression , for example, is a stochastic process due ... to a Promoter biology promoter resulting from Brownian motion . Medicine Stochastic effect, or chance ... of an effect increases with dose. Cancer is a stochastic effect. Stochastic theory of hematopoiesis Geomorphology meander Stochastic theory of meander formation Creativity Simonton 2003, Psych Bulletin argues that creativity in science of scientists is a constrained stochastic behaviour ... more details
ConTeXt is free software the program code i.e. anything not under the code doc code subtree is distributed ... output EN.svg center 600px ConTeXt document See also Portal Free software LaTeX TeX References Reflist ... Free TeX software de ConTeXt es ConTeXt fr ConTeXt hr ConTeXt ja ConTeXt pl ConTeXt sl ConTEXt ...Distinguish ConTEXT Infobox software name ConTeXt logo Image ConTeXt Unofficial Logo.svg The Unofficial ConTeXt logo contextgarden.net logo 200px author Mainly Hans Hagen and http www.pragma ade.com Pragma ... of ConTeXt at contextgarden ref ref http foundry.supelec.fr frs ?group id 14 List of releases of ConTeXt ref ref http foundry.supelec.fr gf project contextrev frs ConTeXt files in Supelec ref operating ... licenses by nc sa 3.0 CC BY NC SA 3.0 ref http wiki.contextgarden.net Read Me Read Me license of ConTeXt code and documentation ref website http wiki.contextgarden.net contextgarden ConTeXt is a general ... and automated capabilities of ConTeXt are extensive, including interfaces for handling microtypography ... it easy to create new layouts and styles without learning the low level TeX macro language. ConTeXt may be compared and contrasted with LaTeX , but the primary thrust of the two are rather distinct. ConTeXt ... time, ConTeXt s unified design avoids the package clashes that can happen with LaTeX. ref http www.tex.ac.uk cgi bin texfaq2html?label context FAQ of the UK TeX Archive ref ref name whatiscontextwiki http wiki.contextgarden.net What is ConTeXt What is ConTeXt page at contextgarden ref ConTeXt ... native drawing engine, ConTeXt integrates a superset of MetaPost called MetaFun ref name whatiscontextwiki .... Metafun can also be used with stand alone MetaPost. ConTeXt also supports the use of other ... generic pgf pgfmanual.pdf PGF TikZ official manual. Version 2.0 . Section 9.1.3 Using the ConTeXt Format . p. 88 ref and PSTricks. ref name list modules http wiki.contextgarden.net Modules List of ConTeXt modules at contextgarden ref ConTeXt also provides a Macro computer science macro package for typesetting ... more details
Wiktionary Wikipedia Books ContextContext may refer to Context language use , the relevant constraints of the communicative situation that influence language use, language variation, and discourse summary Archaeological context , an event in time which has been preserved in the archaeological record Opaque context , linguistic context in which substitution of co referential expressions does not preserve truth Trama mycology context or flesh , the mass of non hymenial tissues that composes the mass of a fungal fruiting body Computing Context computing , the virtual environment required to suspend a running software program Context awareness , a complementary to location awareness Context menu , a menu in a graphical user interface that appears upon user interaction ConTeXt , a macro package for the TeX typesetting system ConTEXT , a text editor for Microsoft Windows Operational context , a temporarily defined environment of cooperation See also lookfrom intitle Contextual disambiguation Contextualization disambiguation Locality disambiguation State disambiguation disambig de Kontext es Contexto fr Contexte nl Context simple Context sk Kontext ... more details
distinguish ConTeXt Infobox Software name ConTEXT logo Image ConTEXT Logo.png screenshot Image ConTEXT 0.98.3.png 250px caption ConTEXT v0.98.6 developer ConTEXT Project released ? frequently updated yes Release version update? Don t edit this page, just click on the version number programming language Delphi programming language Delphi operating system Microsoft Windows language english german genre Text editor license New BSD License citation needed date October 2011 website http www.contexteditor.org www.contexteditor.org ConTEXT is a text editor for Microsoft Windows that can open and edit very large files, while requiring only modest amounts of RAM and hard drive space to run. It has built in Syntax highlighting syntax highlighters for C programming language C C , Delphi programming language Delphi Pascal programming language Pascal , FORTRAN , 80x86 assembler, Java programming language Java , JavaScript , Visual Basic , Perl Common Gateway Interface CGI , HTML , SQL , Python programming language Python , PHP , Tcl Tk , and its own syntax highlighter definition language. Other features ... Interface . ConTEXT can integrate compiler s to compile source code from within the editor, and run ... search and basic regular expressions are supported for searching and replacing. ConTEXT is available in many languages. On 7 September 2007 the creator of ConTEXT announced he wanted to sell the project including the full source, copyrights, website and domain. ref http www.contexteditor.org ConTEXT ... project was bought and ConTEXT Project was set up as a company. citation needed date October 2011 In March 2009 the decision was made to make ConTEXT open source. citation needed date October ... www.contexteditor.org Freeware Text Editor http www.contexteditor.org downloads ConTEXT Downloads Category Windows text editors Category Windows only freeware Windows software stub fr ConTEXT it ConTEXT hu ConTEXT nl ConTEXT pl ConTEXT fi ConTEXT ... more details
Context sensitive is an adjective meaning depending on context or depending on circumstances . It may refer to Context sensitive grammarContext sensitive language Context sensitive help Context sensitive user interface in computing Disambiguation ... more details
Stochastic computing is a collection of techniques that represent continuous values by streams of random ... the similarity in their names, stochastic computing is distinct from the study of randomized algorithm ... to compute math p times q math . Stochastic computing performs this operation using probability instead ..., stochastic computing represents numbers as streams of random bits and reconstructs numbers by calculating ... of reconstruction, devices that perform these operations are sometimes called stochastic averaging processors. In modern terms, stochastic computing can be viewed as an interpretation of calculations ... Image RASCEL stochastic computer 1969.png thumb alt A photograph of the RASCEL stochastic computer. The RASCEL stochastic computer, circa 1969 Stochastic computing was first introduced in a pioneering ... journal last1 Poppelbaum first1 W. last2 Afuso first2 C. last3 Esch first3 J. title Stochastic computing ... cite journal last Gaines first B. title Stochastic Computing journal AFIPS SJCC year 1967 volume 30 ... stochastic computation. A host ref cite book last1 Mars first1 P. last2 Poppelbaum first2 W. title Stochastic and deterministic averaging processors year 1981 ref of these machines were constructed ... computer based on a regular array of stochastic computing element logic year 1969 location University ... and 1970s, stochastic computing ultimately failed to compete with more traditional digital logic, for reasons outlined below. The first and last International Symposium on Stochastic Computing ref cite conference title Proceedings of the first International Symposium on Stochastic Computing ... in the area dwindled over the next few years. Although stochastic computing declined as a general method ... Systems Science title Stochastic Computing Systems last Gaines first B. R. editor last Tou editor ... Computing Machines, Proceedings IEEE, NAPA title A stochastic neural architecture that exploits ... has turned towards stochastic decoding, which applies stochastic computing to the decoding of error ... more details
Refimprove date December 2009 Stochastic cooling is a form of particle beam cooling . It is used in some particle accelerator s and storage ring s to control the Beam emittance emittance of the particle beam s in the machine. This process uses the Signal electrical engineering electrical signals that the individual charged particle s generate in a feedback loop to reduce the tendency of individual particles to move away from the other particles in the beam. It is accurate to think of this as thermodynamic cooling, or the reduction of entropy , in much the same way that a refrigerator or an air conditioner cools its contents. The technique was invented and applied at the Intersecting Storage Rings , ref name overview Citation arxiv physics 0308044 title Stochastic Cooling Overview author John Marriner arxiv physics.acc ph 0308044 doi 10.1016 j.nima.2004.06.025 date 2003 08 11 journal Nuclear Instruments and Methods A volume 532 issue 1 2 pages 11 18 bibcode 2004NIMPA.532...11M ref and later ... National Accelerator Laboratory continues to use stochastic cooling in its antiproton source. The accumulated ... Detector at Fermilab CDF and the D0 experiment . Stochastic cooling in the Tevatron at Fermilab ... RHIC . Technical details This section needs to be edited for clarity by a stochastic cooling expert. Stochastic cooling uses the electrical signals produced by individual particles in a group of particles ... on the depth of the cooling that is required. Stochastic cooling is used to reduce the transverse ... spread of each bunch is not affected by this damping. The key to stochastic cooling is to address individual ... Free electron laser . To achieve cooling the position information is fed back into the particle ... in this context often called kicking in one device. Coupled energy increases with the square of the length ... and gets smaller. The word stochastic in the title stems from the fact that usually only some of the particles ... reflist Accelerator stub DEFAULTSORT Stochastic Cooling Category Accelerator physics de Stochastische ... more details
In probability theory , stochastic drift is the change of the average value of a stochastic process stochastic random process . A related term is the drift rate which is the rate at which the average changes. This is in contrast to the random fluctuations about this average value. For example, the process which counts the number of heads in a series of math n math coin toss es has a drift rate of 1 2 per toss. Stochastic drifts in population studies Longitudinal studies of secular events are frequently conceptualized as consisting of a trend component fitted by a polynomial , a cyclical component often fitted by an analysis based on autocorrelation s or on a Fourier series , and a random component stochastic drift to be removed. In the course of the time series analysis , identification of cyclical and stochastic drift components is often attempted by alternating autocorrelation analysis and differencing of the trend. Autocorrelation analysis helps to identify the correct phase of the fitted model while the successive differencing transforms the stochastic drift component into white noise . Stochastic drift can also occur in population genetics where it is known as Genetic drift . A finite population of randomly reproducing organisms would experience changes from generation to generation in the frequencies of the different genotypes. This may lead to the fixation of one of the genotypes ... can also neutralize the effect of deterministic natural selection on the population. Stochastic ... variable. In this case the stochastic drift can be removed from the data by regressing math y t math ... where math u t math is a zero long run mean stationary random variable here c is a non stochastic ... no drift. In the context of monetary policy , one policy question is whether a central bank ... any stochastic change to the price level permanently affects the expected values of the price level ... analysis Category Stochastic processes Category Economics Category Finance ... more details
In estimation theory in statistics , stochastic equicontinuity is a property of estimator s or of estimation procedures that is useful in dealing with their Asymptotic theory statistics asymptotic behviour as the amount of data increases. It is a version of equicontinuity used in the context of functions of random variables that is, random function s. The property relates to the rate of convergence of random variables convergence of sequences of random variables and requires that this rate is essentially the same within a region of the parameter space being considered. For instance, stochastic equicontinuity, along with other conditions, can be used to show uniform weak convergence, which can be used to prove the convergence of random variables convergence of extremum estimator s. ref Newey, Whitney K. 1991 Uniform Convergence in Probability and Stochastic Equicontinuity , Econometrica , 59 4 , 1161 1167 jstor 2938179 ref Definition Let math H n theta n geq 1 math be a family of random functions defined from math Theta rightarrow reals math , where math Theta math is any normed metric space. Here math H n theta math might represent a sequence of estimators applied to datasets of size n , given that the data arises from a population for which the parameter indexing the statistical model for the data is &theta . The randomness of the functions arises from the data generating process under which a set of observed data is considered to be a realisation of a probabilistic or statistical model. However, in math H n theta math , &theta relates to the model currently being postulated or fitted rather than to an underlying model which is supposed to represent the mechanism generating the data. Then math H n math is stochastically equicontinuous if, for every math epsilon 0 math , there is a math delta 0 math such that math lim n rightarrow infty Pr left sup theta in Theta sup theta in B theta, delta H n theta H n theta epsilon right delta . math Here B &theta , &delta represents ... more details
context date June 2011 Stochastic approximation methods are a family of iterative stochastic optimization ... by Herbert Robbins and Sutton Monro, ref name rm A Stochastic Approximation Method, Herbert Robbins ... math x in Theta math . ref name jsacks Asymptotic distribution of Stochastic Approximation, J. Sacks, Annals of Mathematical Statistics 29 , 1958 , pp. 373 409. ref ref name NJLS Robust Stochastic Approximation Approach to Stochastic Programming, A. Nemirovski, A. Juditsky, G. Lan and A. Shapiro .... ref name NJLS ref name jcsbook Introduction to Stochastic Search and Optimization Estimation ..., Polyak and Juditsky, ref name pj Acceleration of Stochastic Approximation by Averaging, B.T. ... 1978 English . ref for the cases of solving the stochastic optimization problem with continuous convex ..., ref name KW Stochastic Estimation of the Maximum of a Regression Function, Jack Kiefer mathematician ..., proposed the use of Simultaneous perturbation stochastic approximation simultaneous perturbations ... of the dimension math d math . ref name Jsp Adaptive Stochastic Approximation by the Simultaneous Perturbation ... can be fairly restrictive and highly unrealistic. Further Developments in Stochastic Approximation ..., possible noise models, and so on. ref name kushneryin Stochastic Approximation Algorithms and Applications ... ed., titled Stochastic Approximation and Recursive Algorithms and Applications , 2003, ISBN 0387008942. ref ref Stochastic Approximation and Recursive Estimation , Mikhail Borisovich Nevel son and Rafail ... C. Johan Masreliez and R. Douglas Martin were the first to apply stochastic approximation to Robust statistics robust estimation . ref R.D. Martin & C.J. Masreliez, Robust estimation via stochastic approximation . IEEE Trans. Inform. Theory, 21 pp.263 271 1975 . ref See also Stochastic gradient descent Stochastic optimization Simultaneous perturbation stochastic approximation References reflist DEFAULTSORT Stochastic Approximation Category Stochastic optimization Category Statistical approximations ... more details
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