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Statechart
A state diagram is a type of diagram used in computer science and related fields to describe the behavior of systems. State diagrams require that the system described is composed of a finite number of states; sometimes, this is indeed the case, while at other times this is a reasonable abstraction. Many forms of state diagrams exist, which differ slightly and have different semantics. Overview State diagrams are used to give an abstract description of the behavior of a system. This behavior is analyzed and represented by a series of events that can occur in one or more possible states. Hereby "each diagram usually represents objects of a single class and track the different states of its objects through the system". State diagrams can be used to graphically represent finite-state machines (also called finite automata). This was introduced by Claude Shannon and Warren Weaver in their 1949 book ''The Mathematical Theory of Communication''. Another source is Taylor Booth in h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UML State Machine
UML state machine, also known as UML statechart, is an extension of the mathematical concept of a finite automaton in computer science applications as expressed in the Unified Modeling Language (UML) notation. The concepts behind it are about organizing the way a device, computer program, or other (often technical) process works such that an entity or each of its sub-entities is always in exactly one of a number of possible states and where there are well-defined conditional transitions between these states. UML state machine is an object-based variant of Harel statechart, adapted and extended by UML.D. Drusinsky''Modelling and verification using UML statecharts'' Elsevier, 2006 The goal of UML state machines is to overcome the main limitations of traditional finite-state machines while retaining their main benefits. UML statecharts introduce the new concepts of hierarchically nested states and orthogonal regions, while extending the notion of actions. UML state machines hav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
David Harel
David Harel ( he, דוד הראל; born 12 April 1950) is a computer scientist, currently serving as President of the Israel Academy of Sciences and Humanities. He has been on the faculty of the Weizmann Institute of Science in Israel since 1980, and holds the William Sussman Professorial Chair of Mathematics. Born in London, England, he was Dean of the Faculty of Mathematics and Computer Science at the institute for seven years. Biography Harel is best known for his work on Dynamic logic (modal logic), dynamic logic, computability, database theory, software engineering and modelling biological systems. In the 1980s he invented the graphical language of Statecharts for specifying and programming reactive systems, which has been adopted as part of the Unified Modeling Language, UML standard. Since the late 1990s he has concentrated on a scenario-based approach to programming such systems, launched by his co-invention (with W. Damm) of Message sequence chart, Live Sequence Charts. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Finite-state Machine
A finite-state machine (FSM) or finite-state automaton (FSA, plural: ''automata''), finite automaton, or simply a state machine, is a mathematical model of computation. It is an abstract machine that can be in exactly one of a finite number of '' states'' at any given time. The FSM can change from one state to another in response to some inputs; the change from one state to another is called a ''transition''. An FSM is defined by a list of its states, its initial state, and the inputs that trigger each transition. Finite-state machines are of two types— deterministic finite-state machines and non-deterministic finite-state machines. A deterministic finite-state machine can be constructed equivalent to any non-deterministic one. The behavior of state machines can be observed in many devices in modern society that perform a predetermined sequence of actions depending on a sequence of events with which they are presented. Simple examples are vending machines, which dispense p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Accept State
A finite-state machine (FSM) or finite-state automaton (FSA, plural: ''automata''), finite automaton, or simply a state machine, is a mathematical model of computation. It is an abstract machine that can be in exactly one of a finite number of '' states'' at any given time. The FSM can change from one state to another in response to some inputs; the change from one state to another is called a ''transition''. An FSM is defined by a list of its states, its initial state, and the inputs that trigger each transition. Finite-state machines are of two types— deterministic finite-state machines and non-deterministic finite-state machines. A deterministic finite-state machine can be constructed equivalent to any non-deterministic one. The behavior of state machines can be observed in many devices in modern society that perform a predetermined sequence of actions depending on a sequence of events with which they are presented. Simple examples are vending machines, which dispense p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jeffrey Ullman
Jeffrey David Ullman (born November 22, 1942) is an American computer scientist and the Stanford W. Ascherman Professor of Engineering, Emeritus, at Stanford University. His textbooks on compilers (various editions are popularly known as the dragon book), theory of computation (also known as the Cinderella book), data structures, and databases are regarded as standards in their fields. He and his long-time collaborator Alfred Aho are the recipients of the 2020 Turing Award, generally recognized as the highest distinction in computer science. Career Ullman received a Bachelor of Science degree in engineering mathematics from Columbia University in 1963 and his PhD in electrical engineering from Princeton University in 1966. He then worked for three years at Bell Labs. In 1969, he returned to Princeton as an associate professor, and was promoted to full professor in 1974. Ullman moved to Stanford University in 1979, and served as the department chair from 1990 to 1994. He was n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unified Modeling Language
The Unified Modeling Language (UML) is a general-purpose, developmental modeling language in the field of software engineering that is intended to provide a standard way to visualize the design of a system. The creation of UML was originally motivated by the desire to standardize the disparate notational systems and approaches to software design. It was developed at Rational Software in 1994–1995, with further development led by them through 1996. In 1997, UML was adopted as a standard by the Object Management Group (OMG), and has been managed by this organization ever since. In 2005, UML was also published by the International Organization for Standardization (ISO) as an approved ISO standard. Since then the standard has been periodically revised to cover the latest revision of UML. In software engineering, most practitioners do not use UML, but instead produce informal hand drawn diagrams; these diagrams, however, often include elements from UML. History Before UML 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OO Modeling Languages History
OO or oo may refer to: Science and technology * ʻŌʻō, an extinct bird of the genus ''Moho'' * Object-oriented programming, a computer programming paradigm * O.O (also O.o or o.O), an emoticon to represent two eyes and a nose or mouth Transportation * SkyWest Airlines (IATA code: OO) * Belgium ( aircraft registration prefix: OO) * Old Oak Common TMD, a carriage shed (Network Rail depot code: OO) Places * Oô, a commune in France * Oo, Indonesia Art and entertainment * ''OO'' (EP), album by South Korean singer Zion.T * OO, the production code for the 1967 ''Doctor Who'' serial ''The Ice Warriors'' * "O.O" (song), a song by South Korean girl group NMIXX Other uses * Oo (digraph), a digraph in orthography * ‘O‘o stick, a traditional Hawaiian digging bar * Original Oratory, a competitive event in high school forensic competitions * Oakley, Inc. (NYSE stock ticker symbol: OO), subsidiary of Italian company Luxottica * OO gauge, a 1:76.2 modelling scale in model railr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mealy Machine
In the theory of computation, a Mealy machine is a finite-state machine whose output values are determined both by its current state and the current inputs. This is in contrast to a Moore machine, whose output values are determined solely by its current state. A Mealy machine is a deterministic finite-state transducer: for each state and input, at most one transition is possible. History The Mealy machine is named after George H. Mealy, who presented the concept in a 1955 paper, "A Method for Synthesizing Sequential Circuits". Formal definition A Mealy machine is a 6-tuple (S, S_0, \Sigma, \Lambda, T, G) consisting of the following: * a finite set of states S * a start state (also called initial state) S_0 which is an element of S * a finite set called the input alphabet \Sigma * a finite set called the output alphabet \Lambda * a transition function T : S \times \Sigma \rightarrow S mapping pairs of a state and an input symbol to the corresponding next state. * an output functi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moore Machine
In the theory of computation, a Moore machine is a finite-state machine whose current output values are determined only by its current state. This is in contrast to a Mealy machine, whose output values are determined both by its current state and by the values of its inputs. Like other finite state machines, in Moore machines, the input typicallinfluences the next state Thus the input may indirectly influence subsequent outputs, but not the current or immediate output. The Moore machine is named after Edward F. Moore, who presented the concept in a 1956 paper, “ Gedanken-experiments on Sequential Machines.” Formal definition A Moore machine can be defined as a 6-tuple (Q, q_0, \Sigma, O, \delta, G) consisting of the following: * A finite set of states Q * A start state (also called initial state) q_0 which is an element of Q * A finite set called the input alphabet \Sigma * A finite set called the output alphabet O * A transition function \delta : Q \times \Sigma \righ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Generalized Nondeterministic Finite Automaton
In the theory of computation, a generalized nondeterministic finite automaton (GNFA), also known as an expression automaton or a generalized nondeterministic finite state machine, is a variation of a nondeterministic finite automaton (NFA) where each transition is labeled with any regular expression. The GNFA reads blocks of symbols from the input which constitute a string as defined by the regular expression on the transition. There are several differences between a standard finite state machine and a generalized nondeterministic finite state machine. A GNFA must have only one start state and one accept state, and these cannot be the same state, whereas an NFA or DFA both may have several accept states, and the start state can be an accept state. A GNFA must have only one transition between any two states, whereas a NFA or DFA both allow for numerous transitions between states. In a GNFA, a state has a single transition to every state in the machine, although often it is a conv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
