Search results
Results from the WOW.Com Content Network
Notice that the actual constraint graph representing this problem must contain two edges between X and Y since C2 is undirected but the graph representation being used by AC-3 is directed. AC-3 solves the problem by first removing the non-even values from of the domain of X as required by C1, leaving D(X) = { 0, 2, 4 }.
The unbounded variant was shown to be NP-complete in 1975 by Lueker. [3] Both the bounded and unbounded variants admit an FPTAS (essentially the same as the one used in the 0-1 knapsack problem). If the items are subdivided into k classes denoted N i {\displaystyle N_{i}} , and exactly one item must be taken from each class, we get the multiple ...
Constraints with one, two, or more variables are called unary, binary, or higher-order constraints. The number of variables in a constraint is called its arity. The hidden transformation replaces each constraint with a new, hidden variable. The hidden transformation converts an arbitrary constraint satisfaction problem into a binary one.
The AC-3 algorithm improves over this algorithm by ignoring constraints that have not been modified since they were last analyzed. In particular, it works on a set of constraints that initially contains all constraints; at each step, it takes a constraint and enforces arc consistency; if this operation may have produced a violation of arc ...
In the full AC model the complete Kirchhoff laws are used: this results in highly nonlinear and nonconvex constraints in the model. When the full AC model is used, UC actually incorporates the optimal power flow problem, which is already a nonconvex nonlinear problem.
Unary function, a function that takes one argument; in computer science, a unary operator is a subset of unary function; Unary operation, a kind of mathematical operator that has only one operand; Unary relation, a mathematical relation that has one argument; Unary coding, an entropy encoding that represents a number n with n − 1 ones ...
Main page; Contents; Current events; Random article; About Wikipedia; Contact us; Help; Learn to edit; Community portal; Recent changes; Upload file
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.