Information Technology Reference
In-Depth Information
5. Object-oriented Constraint Language COPS
COPS system, developed by intelligent information processing laboratory of
Institute of Computing Technology(ICT),Chinese Academy of Sciences, which
utilizes object-oriented technology and combine declarative constraint
representation and constraint hierarchy together. COPS absorbs regular
language(mainly object-oriented programming language)in form. The solution
inside COPS is realized by using constraint reasoning mechanism, which
combines declarative constraint representation and constraint hierarchy to realize
structured encapsulation of knowledge. By fully taking advantages of constraint
representation and hierarchy, COPS tries to become a constraint satisfaction
system with strong expressing ability and high solving efficiency. Design of
COPS considers requirement of software engineering and try to determine
uncertain problems: to realize iterative computation, COPS does not utilize only
iterate statements but allow both the selection and iteration statements; Through
overload of class methods, a constraint may have multiple implementation, which
can improve the execution efficiency of program. COPS system is also an open
system of gradual increment, in which users can realize the new data type and
constraint relation through hierarchy definition. The constrain representation
language COPS, has a lot of characteristics of artificial intelligence programming
languages, such as constraint propagation, target-oriented and data-driven
problem solving, limited backtracking, inheritance of object hierarchy and so on.
6. ILOG
ILOG Company established in 1987, whose general headquarter lies in Paris of
France and California of U.S.A., is the world's leading provider of software
component suite in optimization, visualization and business rule management
fields, and applies the optimize algorithms to business software. The products of
ILOG are widely used in telecommunications, traffic, national defense, electricity
and the delivery etc.. ILOG Solver represents constraints by using modeling
language.
3.2 Backtracking
Generate-and-test method is simplest and most direct to solve constraint
satisfaction problem. Each possible combination of the variables is generated and
then tested until a successful tested combination is found. This method is
obviously less effective. Backtracking is a direct improvement for generate-and-
