Defining heuristic knowledge

For multicriteria optimization, the individual criteria are described by means of fuzzy sets and are aggregated then to an appropriate objective function. To define the membership functions of those objective functions, heuristic knowledge can be included. 

It is appropriate at this point to define what is meant by a heuristic and indicate the pattern of discussions in the other sections of this chapter. A heuristic is commonly defined as a general rule of thumb, or procedure to arrive at a solution in the absence of a detailed analysis. More specifically, it is a set of rules, often based on common knowledge, used to... 

Knowledge = Pacts + Beliefs + Heuristics This statement doesn t facilitate an understanding of knowledge in detail but Instead defines its boundaries in rather broad terms. 

The Evaluation is an overall measure for the applicability and importance of a Claim. The Evaluation class is not further specified in the Evaluation module. Instead, tailored measurement units can be defined depending on the nature of the decision problem in consideration. For instance, in the early stages of a design process, a coarse-grained evaluation of Claims is sufficient because not much knowledge about relevant aspects of a design problem is available and heuristics as well as screening and short-cut methods are applied. 

However, there is a difference between conventional software algorithms and expert systems. Whereas conventional algorithms have a clearly defined result, an expert system may provide no answer or just one with a certain probability. The methodology used here is heuristic programming, and, depending on the point of view, the terms expert system and knowledge-based or rule-based system are often used synonymously. 

The objects defined in the level above the Knowledge Base exist to perform the problem solving process. Amongst them is an object which co-ordinates the systematic search for a solution which possesses several heuristic methods and an object to evaluate equations arithmetically. There is also an object to intelligently translate equations and quantities from the symbolic format an engineer or scientist employs into the internal format used by QPS. 

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