Contextfree may refer to Concepts contextfree grammar deterministic contextfree grammar stochastic contextfree grammar weighted contextfree grammar contextfree language Software ContextFree , a computer language for contextfree grammars disambig ... more details
In formal language theory , a contextfree language is a formal language language generated by some contextfree grammar . 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 Undecidable language undecidable for arbitrary contextfree grammar 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 ... 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 contextfree grammar . The intersection of a contextfree language and a regular language is always contextfree. There exist context sensitive language s which are not contextfree. To prove that a given language is not context ... more details
A weighted contextfree grammar WCFG is a contextfree grammar 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 stochastic contextfree grammar 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
A deterministic contextfree language is a formal language which is defined by a deterministic contextfree grammar . 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 contextfree grammar . 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 .... The deterministic contextfree languages are exactly those recognized by some LR grammar . ref ... 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
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
refimprove date February 2012 In formal language theory , a contextfree grammar CFG is a formal grammar ... w can be empty . The formal language language s generated by contextfree grammars are known as the contextfree language s. Contextfree grammars are important in linguistics for describing ... use the term phrase structure grammar to refer to contextfree grammars, whereby phrase structure grammars ... . A contextfree grammar provides a simple and mathematically precise mechanism for describing the methods ... and reference are not part of the contextfree grammar, but the basic recursive structure of sentences ... and adverbs are swallowed by nouns and verbs, is described exactly. The formalism of contextfree ... of natural language was described by contextfree rules combined with transformation rules. Block structure ... project 1957 1960 , which, as a consequence, also featured a contextfree grammar to describe the resulting ... identified with contextfree grammar rules, especially in computer science. Formal constraints ... parser s are simpler algorithms that deal only with more restrictive subsets of contextfree grammars. Formal definitions A contextfree grammar 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 ... to be a contextfree language CFL , if there exists a CFG math G , math , such that math L , ,L G math . Proper CFGs A contextfree grammar is said to be proper , if it has no inaccessible symbols math ..., S &rarr , is contextfree. It is not proper since it includes an production. A typical derivation ... L G ww R w in a,b math . The language is contextfree, however it can be proved that it is not regular. Examples Well formed parentheses The canonical example of a contextfree grammar is parenthesis ... can be derived in that grammar However, there is no contextfree grammar for generating all sequences ... grammar is contextfree, however not all contextfree grammars are regular. It is common to list ... more details
Generalized Contextfree Grammar 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 contextfree grammar, eventually yielding just compositions composition functions applied to string tuples or other compositions . The composition functions are then applied, reducing successively reducing the tuples to a single tuple. Example A simple translation of a contextfree grammar 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 math w R math is the string reverse of math w math , we can define the composition function conc as in 2a ... rangle, langle a rangle math math langle abbbba rangle math Linear Contextfree Rewriting Systems LCFRSs ... and regular is called a Linear Contextfree Rewriting System LCFRS , a subset of the GCFGs with strictly ... Generalized ContextFree Grammar Category Formal languages Category Grammar frameworks ... more details
Synchronous contextfree grammars SynCFG or SCFG not to be confused with Stochastic contextfree grammar stochastic 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
Weasel date June 2010 A stochastic contextfree grammar SCFG also probabilistic contextfree grammar , PCFG is a contextfree grammar 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 stochastic grammar than others. SCFGs extend contextfree grammars in the same way that hidden Markov model s extend regular grammar s. SCFGs have application in areas as diverse as Natural language processing to the study of RNA molecules. SCFGs are a specialized form of weighted contextfree grammar s. Techniques A variant of the CYK algorithm finds the Viterbi algorithm Viterbi parse of a sequence for a given SCFG. The Viterbi parse is the most likely derivation parse of the sequence by the given SCFG. The Inside Outside algorithm is an analogue of the Forward backward algorithm Forward Backward algorithm , and can be used to compute the total probability of all derivations that are consistent with a given sequence, based on some SCFG. This is equivalent to the probability of the SCFG generating the sequence, and is intuitively a measure of how consistent the sequence is with the given grammar. The Inside outside algorithm Inside Outside algorithms can also be used to compute the probabilities that a given production ... language processing Contextfree grammars were originally conceived in an attempt to model natural ... xpl freeabs all.jsp?arnumber 1566496 ref RNA Contextfree grammars are adept at modeling the secondary ... pairing can be represented in a contextfree grammar the major exception being pseudoknot s . For example ... Stochastic ContextFree Grammar Category Bioinformatics Category Formal languages Category 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 ... 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
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 grammar Context sensitive language Context sensitive help Context sensitive user interface in computing Disambiguation ... more details
Orphan date February 2009 An operating context OC for an application is the external environment that influences its operation. For a mobile application, the OC is defined by the hardware and software environment in the device, the target user, and other constraints imposed by various other stakeholders, such as a carrier. This concept differs from the operating system OS by the impact of these various other stakeholders. Example Here is an example of one device, with one operating system, changing its operating context without changing the OS. A user with a mobile phone changes SIM card s, removing card A, and inserting card B. The phone will now make any telecommunications network network calls over cell phone carrier A s network, rather than B s. Any applications running on the phone will run in a new operating context, and will often have to change functionality to adapt to the abilities, and business logic, of the new carrier. The network, spectrum, and wireless protocol all change in this example. These changes must be reflected back to the user, so the user knows what experience to expect, and thus these changes all change the user interface UI also. Hardware agnostic context Situations exist where one can program in a context, with less concern about what hardware it will actually run on. Examples include Flash and Android operating system Android . Unfortunately, it also quite common that code in a hardware freecontext will see hardware specific bugs. This is common with software written for, that interacts more directly with, personal computer PC hardware, or mobile phone s. References http www.comp.nus.edu.sg damithch df device fragmentation.htm Fragmentation of Mobile Applications Operating context is defined in this article See also List of operating systems Comparison of operating systems Category Computing terminology comp stub ... more details
Context awareness is defined complementary to location awareness. Whereas location may serve as a determinant for resident processes, context may be applied more flexibly with mobile computing with any moving entities, especially with bearers of smart communicators. Context awareness originated as a term ... cite conference author Rosemann, M., & Recker, J. year 2006 title Context aware process design Exploring ... location Luxembourg publisher Namur University Press editor T. Latour & M. Petit ref See also Context aware delegation Qualities of context It is common sense to understand that context awareness did ... context stems from a study of human text and the idea of situated cognition, that context ... of recorded ancient analysis of context and interpretation is the writings of the Legalism Chinese .... In Western philosophy, one could easily identify ideas about context awareness from Greek epistemology. A search for the words situated learning will show that the study of context awareness goes back ... context awareness as early as the formation of the discipline. Context defines some rules of inter ... of context have been proposed in the past. Dey and Abowd 1999 ref ftp ftp.cc.gatech.edu pub gvu tr 1999 99 22.pdf Towards a Better Understanding of Context and Context Awareness ref distinguish between the context types location , identity , activity and time . Kaltz et al. 2005 ref name kaltz2005 cite journal author Kaltz, J.W., Ziegler, J., Lohmann, S. year 2005 title Context aware Web Engineering ... of entities that work in a coherence of context, as e.g. teams at work or also single bearers with a multiplicity of appliances. Some classical understanding of context in business processes is derived ... or access to location, function, data Accounting, which means i.e. the relation to order context ... additionally location and time as stated. Computer science In computer science context awareness ..., or an intelligent stimulus, react accordingly. The term context awareness in ubiquitous computing ... more details
saved book title Context subtitle Phenomena cover image cover color ContextContextContext dn date August 2011 Context language use ContextContext principle Triangle of reference The Message in the Bottle Cognitive anthropology Cognitive linguistics Cognitive psychology Cognitive science Cognitive semantics Frame semantics linguistics Frame semantics Situation semantics Semiotics Syntax Pragmatics Psycholinguistics Educational psychology Phenomenology philosophy Phenomenology Systems science Behaviorism Psychological nativism Nativism Cognitive revolution Semantic externalism Interpretivism legal Legal interpretivism Synoptic philosophy Yin and yang Contextualism Holism Phenomena Indexicality Anaphora rhetoric Anaphora Metaphor Analogy Categorization Category Family resemblance Sense and reference Intension Denotation Connotation Implicature Syllogism Entailment Presupposition Thick description Affordance Latent semantic analysis Key Word in Context Reality mapping ground Cognitive architecture Cognitive model Cognitive map Mind map Mental space Mental model Mental Models Gentner Stevens book Mental Models Archetype Stereotype Schema psychology Schema Behavioral script Scripts artificial intelligence Scripts Frame artificial intelligence Frame Frame of reference FrameNet Semantic Web Semantic network Intentionality Language of thought Representational theory of mind Representative realism Conceptual metaphor Conceptual blending Instructional scaffolding Neuro linguistic programming Knowledge representation and reasoning Domain of discourse Community of practice Intertextuality Intersubjectivity Relativism Convention norm Convention Grammar Connectionism Constructionism dn date August 2011 Constructivism dn date August 2011 Reasoning ground Logical reasoning Inductive reasoning Deductive reasoning Abductive reasoning Defeasible reasoning Case based reasoning Logic programming ... Open Source Initiative Free software movement Consilience Theory of everything Tree of Knowledge ... more details
Context Management is a dynamic computer process that uses subjects of data in one application, to point to data resident in a separate application also containing the same subject. Context Management allows users to choose a subject once in one application, and have all other applications containing information on that same subject tune to the data they contain, thus obviating the need to redundantly select the subject in the varying applications. An example from the healthcare industry where Context Management is widely used, multiple applications operating in context through use of a context manager would allow a user to select a patient i.e., the subject in one application and when the user enters the other application, that patient s information is already pre fetched and presented, obviating the need to re select the patient in the second application. The further the user drills into the application e.g., test, result, diagnosis, etc. all context aware applications continue to drill down into the data, in context with the user s requests. Context Management is gaining in prominence in healthcare due to the creation of the Clinical Context Object Workgroup standard committee CCOW which has created a standardized protocol enabling applications to function in a context aware state. Context Management is gaining in the Business Rule market as well. Knowing the context of any information exchange is critical. For example a seller may need to know such things as is this shipment urgent, is this a preferred customer, do they need English or Spanish, what model is the part for? Without context, mistakes and run on costs rapidly ensue. In automating information integration, knowing and defining context of use is the single most pervasive and important factor. This context mechanism is at the heart of allowing users to quantify what their context factors are precisely, this removes the guess work from business transaction exchanges between business transaction information ... more details
WS Context is a web services specification developed by OASIS organization . It is part of the WS CAF suite. Its purpose is to provide a means to reference a shared context, which relates a set of interactions between web services termed an activity . This context provides details of the application specific execution environment for these services, and is typically included in the header of SOAP message. Contexts may be passed by value, or by reference, in which case they are retrieved using a Context Manager service. A Context Service is described, which allows management of activities by means of the begin and complete operations, which create and destroy the context respectively. References Little, M., Newcomer, E., Pavlik, G. Eds Web Services Context Specification Version 1.0 OASIS, 2007 http docs.oasis open.org ws caf ws context v1.0 wsctx.html retrieved 2008 01 03 Web software stub Category Web service specifications hu WS Context ... more details
thread switching latency date April 2012 A context switch is the computing process of storing and restoring the State computer science state Context computing context of a Central processing unit CPU ... computing process es to share a single Central processing unit CPU . The context switch is an essential feature of a computer multitasking multitasking operating system . Context switches are usually computationally intensive and much of the design of operating system s is to optimize the use of context switches. A context switch can mean a Processor register register context switch, a task context switch, a Thread computer science thread context switch, or a process context switch. What constitutes the context is determined by the processor and the operating system. Switching from one process ... where a context switch needs to occur. They are Multitasking Most commonly, within some Scheduling ... run. This context switch can be triggered by the process making itself unrunnable, such as by waiting ... will gain control to perform a context switch. Interrupt handling Modern architectures ... of the context at least enough to allow the handler to return to the interrupted code . The handler may save additional context, depending on details of the particular hardware and software designs. Often only a minimal part of the context is changed in order to minimize the amount of time spent handling ... interrupts, but instead the handler executes in the often partial context established at the beginning of interrupt handling. Once interrupt servicing is complete, the context in effect before the interrupt ... in an operating system, a context switch is not necessary a mode transition is not by itself a context switch. However, depending on the operating system, a context switch may also take place at this time. Context switch steps In a switch, the state of the first process must be saved somehow, so that, when ..., it can now load the PCB and context of the second process. In doing so, the program counter from the PCB ... more details
Context analysis is a method to analyze the environment in which a business operates. Environmental scanning mainly focuses on the macro environment of a business. But context analysis considers the entire environment of a business, its internal and external environment. This is an important aspect of business plan ning. One kind of context analysis, called SWOT analysis , allows the business to gain an insight into their strengths and weaknesses and also the opportunities and threats posed by the market within which they operate. The main goal of a context analysis, SWOT or otherwise, is to analyze the environment in order to develop a strategic plan of action for the business. Context analysis also refers to a method of sociological analysis associated with Scheflen 1963 which believes that a given act, be it a glance at another person, a shift in posture, or a remark about the weather, has no intrinsic meaning. Such acts can only be understood when taken in relation to one another. Kendon, 1990 16 . This is not discussed here only Context Analysis in the business sense is. Define market or subject The first step of the method is to define a particular market or subject one wishes to analyze and focus all analysis techniques on what was defined. A subject, for example, can be a newly proposed product idea. Trend Analysis The next step of the method is to conduct a trend analysis ... analysis are Political, Economical, Social and Technological but for context analysis Demographic trends ... the major steps involved in context analysis. All these steps resulted in data that can be used ..., opportunities and threats summarize the entire context analysis. A SWOT i matrix, depicted in the table ... without having to make major changes. Strategic Plan The ultimate goal of context analysis is to develop ... context analysis to gain insight into the environment of the business in order to develop a strategic ... industries and competitors. New York Free Press Kendon, A. 1990 . Conducting Interaction Patterns ... more details
Refimprove date November 2009 Image Context menu.png frame right A desktop context menu in GNOME which can be customized Image Context menu windows.png thumb 233px right Context menus in Windows XP are customizable by third party software. A context menu also called contextual , shortcut , and popup .... A context menu offers a limited set of choices that are available in the current state, or context ... user interface selected object . History Context menus first appeared in the Smalltalk ... brought the main menu which was vertical and automatically changed depending on context to the location ... for the time NextStep screen. Implementation Context menus are opened via various forms of user interaction that target a region of the GUI that supports context menus. The specific form of user interaction ... button opens a context menu for the region that is under the mouse pointer. On systems that support one button mice, context menus are typically opened by pressing and holding the primary mouse button ... opens a context menu for the region that has Focus computing focus . Context menus are sometimes ... menu entries after clicking an arrow icon on the context menu, otherwise executing an action associated ... window manager s provide context menu functionality 9wm icewm middleclick and rightclick context ... manager sawfish Usability Context menus have received some criticism from usability analysts when improperly used, as some applications make certain features only available in context menus, which may confuse even experienced users especially when the context menus can only be activated in a limited area of the application s client window . Context menus usually open in a fixed position under ... the menu will be displaced thus reducing consistency and impeding use of muscle memory . If the context menu is being triggered by keyboard, such as by using Shift F10, the context menu appears instead ... Microsoft s guidelines call for using the term context menu only in programming and other ... more details
In computer science, a task context process computing process , thread computer science thread ... is the minimal set of data used by this task that must be saved to allow a task interrupt ion at a given date, and a continuation of this task at the point it has been interrupted and at an arbitrary future date. The concept of context assumes significance in the case of interruptible tasks, wherein upon being interrupted the processor saves the context and proceeds to serve the Interrupt service routine . Thus the smaller the context the smaller is the latency. These data are located in Processor registers Memory used by the task On some Operating systems , control registers used by the system to manage the task The storage memory files is not concerned by the task context in the case of a context switch even if this can be stored for some uses checkpointing . Context types In some computer languages like C , there is also the concept of safe secure context . For instance, if an Array data type array is needed inside a struct C programming language structure , it can be added to it since version 2.0, but only in an unsafe unsecure context. ref http en.wikibooks.org wiki C Sharp Programming Classes Structures Structures in C 2.0 ref Here is an example code source lang CSharp struct ParameterRepresentation char target char taskStart char taskType fixed byte traceValues m MAX BYTES source The http en.wikibooks.org wiki C Sharp Programming Keywords fixed fixed keyword prevents the Garbage collector computing garbage collector from relocating this variable. The access to an array is like in C , i.e. using pointer arithmetic, where individual elements of the array can be accessed ... article view 04099921013 1431 Context and Adaptivity in Pervasive Computing Environments Links with Software ... cube network.eu km terms c contextContext S Cube Knowledge Model Categories DEFAULTSORT Context ... d ex cution pt Contexto computa o simple Context computing ... more details
An operational context OLC for an operation is the external environment that influences its operation. For a mobile application, the OLC is defined by the combined hardware firmware software configurarions of several appliances or devices, as well as the bearer of the mobiles of these units and other work position environment this person as the key stakeholder makes use of in timely, spatial and modal coincidence. This concept differs from the operating context and does not address the operating system of computers. Classic Example The classic example is defined by the electronic leash configuration, where one mobile appliance is wirelessly tethered to another such appliance. The function of this electronic leash is to set an aural alarm with any of these two in case of unintentional leaving one of these two behind. Implementing the example Several suppliers offer the electronic leash solution. A new aspect has been launched with Bluetooth low energy for better economised battery life cycle. Special trimming serves for two years operation from a button cell ref http www.gsm modem.de M2M m2m apps casio bluetooth low energy watch ref . References references http www.comp.nus.edu.sg damithch df device fragmentation.htm Fragmentation of Mobile Applications Operating context is not topic of this article. See also Ambiguity Bluetooth Bluetooth low energy Context computing Context Contiguity Electronic leash Operating context Multilateration Unilateration Category Communication Category Telecommunications Category Wireless ... more details
In the philosophy of language , the context principle is a form of semantic holism holding that a philosopher should never ... ask for the meaning of a word in isolation, but only in the context of a proposition Frege 1884 1980 x . It is one of Gottlob Frege s three fundamental principles for philosophical analysis, first discussed in his Introduction to the Foundations of Arithmetic Grundlagen der Arithmetik , 1884 . Frege argued that many philosophical errors, especially those related to psychologism in the philosophy of logic and philosophy of mathematics , could be avoided by adhering carefully to the context principle. The view of meaning expressed by the context principle is sometimes called contextualism , but should not be confused with the common contemporary use of the term contextualism in epistemology or ethics. The contrasting view, that the meanings of words or expressions can be or must be determined prior to, and independently of, the meanings of the propositions in which they occur, is often referred to as compositionalism. The context principle also figures prominently in the work of other Analytic philosophy Analytic philosophers who saw themselves as continuing Frege s work, such as Bertrand Russell and Ludwig Wittgenstein . Formulations of the Context Principle Gottlob Frege, Introduction to The Foundations of Arithmetic 1884 1980 In the enquiry that follows, I have kept to three fundamental principles always to separate sharply the psychological from the logical, the subjective from the objective never to ask for the meaning of a word in isolation, but only in the context of a proposition never to lose sight of the distinction between concept and object. Ludwig Wittgenstein, Tractatus Logico Philosophicus 1921 1922 3.3 Only the proposition has sense only in the context of a proposition has a name meaning. ... 3.314 An expression has meaning only in a proposition. Every variable can be conceived as a propositional variable . Including the variable ... more details
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