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Constraint Length
Constraint may refer to: * Constraint (computer-aided design), a demarcation of geometrical characteristics between two or more entities or solid modeling bodies * Constraint (mathematics), a condition of an optimization problem that the solution must satisfy * Constraint (mechanics), a relation between coordinates and momenta * Constraint (computational chemistry) * Constraint (information theory), the degree of statistical dependence between or among variables * ''Constraints'' (journal), a scientific journal * Constraint (database), a concept in relational database Particular types of constraint * Biological constraints, factors which make populations resistant to evolutionary change * Carrier's constraint on lung function in long thin animals * Finite domain constraint, in mathematical solution-finding * Integrity constraints in databases ** Check constraint ** Foreign key constraint * Specific types of mechanical constraints: ** First-class constraint and second-class ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Constraint (computer-aided Design)
A constraint in computer-aided design (CAD) software is a limitation or restriction imposed by a designer or an engineer upon Geometry, geometric properties of an entity of a design model (i.e. sketch) that maintains its structure as the model is manipulated. These properties can include relative length, angle, orientation, size, shift, and displacement. The plural form ''constraints'' refers to demarcations of geometrical characteristics between two or more entities or solid modeling bodies; these delimiters are definitive for properties of theoretical physical position and motion, or displacement in parametric design. The exact terminology, however, may vary depending on a CAD program vendor. Constraints are widely employed in CAD software for solid modeling, computer-aided architectural design such as building information modeling, computer-aided engineering, assembly modeling, and Computer-aided technologies, other CAD subfields. Constraints are usually used for the creation of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nonholonomic System
A nonholonomic system in physics and mathematics is a physical system whose state depends on the path taken in order to achieve it. Such a system is described by a set of parameters subject to differential constraints and non-linear constraints, such that when the system evolves along a path in its parameter space (the parameters varying continuously in values) but finally returns to the original set of parameter values at the start of the path, the system itself may not have returned to its original state. Nonholonomic mechanics is an autonomous division of Newtonian mechanics. Details More precisely, a nonholonomic system, also called an ''anholonomic'' system, is one in which there is a continuous closed circuit of the governing parameters, by which the system may be transformed from any given state to any other state. Because the final state of the system depends on the intermediate values of its trajectory through parameter space, the system cannot be represented by a conserv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Restraint (other)
Restraint may refer to: A form of control * Restraint, or self-control, a personal virtue * Medical restraint, form of general physical restraint used for medical purposes * Physical restraint, the practice of rendering people helpless or keeping them in captivity by means such as handcuffs, ropes, straps, etc. Arts, entertainment, and media * ''Restraint'' (book), a non-fiction book on international relations by Barry Posen * ''Restraint'' (2008 film), an Australian thriller directed by David Deenan * ''Restraint'' (2017 film), an American horror directed by Adam Cushman Legal terminology * Judicial restraint, a theory of judicial interpretation that encourages judges to limit the exercise of their own power * Prior restraint, a government's actions that prevent materials from being distributed * Restraint on alienation, in property law, a clause that seeks to prohibit the recipient of property from transferring his or her interest * Restraint of trade Restraints o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optimality Theory
Optimality theory (frequently abbreviated OT) is a linguistic model proposing that the observed forms of language arise from the optimal satisfaction of conflicting constraints. OT differs from other approaches to phonological analysis, which typically use rules rather than constraints. However, phonological models of representation, such as autosegmental phonology, prosodic phonology, and linear phonology (SPE), are equally compatible with rule-based and constraint-based models. OT views grammars as systems that provide mappings from inputs to outputs; typically, the inputs are conceived of as underlying representations, and the outputs as their surface realizations. It is an approach within the larger framework of generative grammar. Optimality theory has its origin in a talk given by Alan Prince and Paul Smolensky in 1991 which was later developed in a book manuscript by the same authors in 1993. Overview There are three basic components of the theory: * Generator () t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loading Gauge
A loading gauge is a diagram or physical structure that defines the maximum height and width dimensions in railway vehicles and their loads. Their purpose is to ensure that rail vehicles can pass safely through tunnels and under bridges, and keep clear of platforms, trackside buildings and structures. Classification systems vary between different countries, and loading gauges may vary across a network, even if the track gauge is uniform. The term loading gauge can also be applied to the maximum size of road vehicles in relation to tunnels, overpasses and bridges, and doors into automobile repair shops, bus garages, filling stations, residential garages, multi-storey car parks and warehouses. A related but separate gauge is the structure gauge, which sets limits to the extent that bridges, tunnels and other infrastructure can encroach on rail vehicles. The difference between these two gauges is called the clearance. The specified amount of clearance makes allowance for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Constraint Satisfaction Problem
Constraint satisfaction problems (CSPs) are mathematical questions defined as a set of objects whose state must satisfy a number of constraints or limitations. CSPs represent the entities in a problem as a homogeneous collection of finite constraints over variables, which is solved by constraint satisfaction methods. CSPs are the subject of research in both artificial intelligence and operations research, since the regularity in their formulation provides a common basis to analyze and solve problems of many seemingly unrelated families. CSPs often exhibit high complexity, requiring a combination of heuristics and combinatorial search methods to be solved in a reasonable time. Constraint programming (CP) is the field of research that specifically focuses on tackling these kinds of problems. Additionally, the Boolean satisfiability problem (SAT), satisfiability modulo theories (SMT), mixed integer programming (MIP) and answer set programming (ASP) are all fields of research ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Constraint Satisfaction
In artificial intelligence and operations research, constraint satisfaction is the process of finding a solution through a set of constraints that impose conditions that the variables must satisfy. A solution is therefore an assignment of values to the variables that satisfies all constraints—that is, a point in the feasible region. The techniques used in constraint satisfaction depend on the kind of constraints being considered. Often used are constraints on a finite domain, to the point that constraint satisfaction problems are typically identified with problems based on constraints on a finite domain. Such problems are usually solved via search, in particular a form of backtracking or local search. Constraint propagation is another family of methods used on such problems; most of them are incomplete in general, that is, they may solve the problem or prove it unsatisfiable, but not always. Constraint propagation methods are also used in conjunction with search to make ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Constraint Logic Programming
Constraint logic programming is a form of constraint programming, in which logic programming is extended to include concepts from constraint satisfaction. A constraint logic program is a logic program that contains constraints in the body of clauses. An example of a clause including a constraint is . In this clause, is a constraint; A(X,Y), B(X), and C(Y) are Literal (mathematical logic), literals as in regular logic programming. This clause states one condition under which the statement A(X,Y) holds: X+Y is greater than zero and both B(X) and C(Y) are true. As in regular logic programming, programs are queried about the provability of a goal, which itself may contain constraints in addition to literals. A proof for a goal is composed of clauses whose bodies are satisfiable constraints and literals that can in turn be proved using other clauses. Execution is performed by an interpreter, which starts from the goal and Recursion, recursively scans the clauses trying to prove the goa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Constraint Programming
Constraint programming (CP) is a paradigm for solving combinatorial problems that draws on a wide range of techniques from artificial intelligence, computer science, and operations research. In constraint programming, users declaratively state the constraints on the feasible solutions for a set of decision variables. Constraints differ from the common primitives of imperative programming languages in that they do not specify a step or sequence of steps to execute, but rather the properties of a solution to be found. In addition to constraints, users also need to specify a method to solve these constraints. This typically draws upon standard methods like chronological backtracking and constraint propagation, but may use customized code like a problem-specific branching heuristic. Constraint programming takes its root from and can be expressed in the form of constraint logic programming, which embeds constraints into a logic program. This variant of logic programming is due ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Constraint Algorithm
In computational chemistry, a constraint algorithm is a method for satisfying the Newtonian motion of a rigid body which consists of mass points. A restraint algorithm is used to ensure that the distance between mass points is maintained. The general steps involved are: (i) choose novel unconstrained coordinates (internal coordinates), (ii) introduce explicit constraint forces, (iii) minimize constraint forces implicitly by the technique of Lagrange multipliers or projection methods. Constraint algorithms are often applied to molecular dynamics simulations. Although such simulations are sometimes performed using internal coordinates that automatically satisfy the bond-length, bond-angle and torsion-angle constraints, simulations may also be performed using explicit or implicit constraint forces for these three constraints. However, explicit constraint forces give rise to inefficiency; more computational power is required to get a trajectory of a given length. Therefore, internal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Constrained Writing
Constrained writing is a literary technique in which the writer is bound by some condition that forbids certain things or imposes a pattern. Constraints are very common in poetry, which often requires the writer to use a particular verse form. Description Constraints on writing are common and can serve a variety of purposes. For example, a text may place restrictions on its vocabulary, e.g. Basic English, copula-free text, defining vocabulary for dictionaries, and other limited vocabularies for teaching English as a second language or to children. In poetry, formal constraints abound in both mainstream and experimental work. Familiar elements of poetry like rhyme and meter are often applied as constraints. Well-established verse forms like the sonnet, sestina, villanelle, limerick, and haiku are variously constrained by meter, rhyme, repetition, length, and other characteristics. Outside of established traditions, particularly in the avant-garde, writers have produced a var ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Constrained Optimization
In mathematical optimization, constrained optimization (in some contexts called constraint optimization) is the process of optimizing an objective function with respect to some variables in the presence of constraints on those variables. The objective function is either a cost function or energy function, which is to be minimized, or a reward function or utility function, which is to be maximized. Constraints can be either hard constraints, which set conditions for the variables that are required to be satisfied, or soft constraints, which have some variable values that are penalized in the objective function if, and based on the extent that, the conditions on the variables are not satisfied. Relation to constraint-satisfaction problems The constrained-optimization problem (COP) is a significant generalization of the classic constraint-satisfaction problem (CSP) model. COP is a CSP that includes an ''objective function'' to be optimized. Many algorithms are used to hand ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
