A Knowledge-based Fish Diseases Diagnosis Reasoning System

With the guidance of knowledge-based diagnosis reasoning theory, the frame which can be used to guide developing fish disease diagnosis expert system from the point of technical view was brought forward in the dissertation. The frame includes fish disease diagnosis knowledge conceptualization, the description of diagnosis problems, diagnosis knowledge representation, the construction and solution of diagnosis, the development of diagnosis system and so on.After analyzing theoretically conceptions involved in fish disease diagnosis, fish disease occurring mechanism and the process of fish disease diagnosis, the definition of fish disease diagnosis, the diagnosis reasoning model and the diagnosis reasoning form were confirmed in the article, which perfect the theory of fish disease diagnosis reasoning. In allusion to much pathogen, much diseases occurring and spreading in the same time, double deck cause and effect network model including disease, symptom and cause factors was constructed in the article. In the symptom-disease deck, based on analyzing manifold uncertainty having existence in the process of diagnose fish disease, such as randomicity, fuzzy and imperfection, fuzzy factor in the process of taking symptom was inducted into parsimonious covering theory, the diagnosis model which based on parsimonious covering theory and fuzzy theory was constructed and it was applied into the solution of fish disease diagnosis problem. After obtaining disease, on the ground of the logic relation between disease and cause, the problem of disease-pathogeny was transformed into 0-1 integers planning model, parsimonious covering theory and Tabu search were united to solve the problem of diagnosis. It is proved that Tabu search can enhance veracity and speed in the process of diagnosing fish disease.In order to obtain effectively fish diagnosis knowledge and establish general, reliable and accurate knowledge database, knowledge obtaining is divided into five stages, such as problem identify, knowledge conceptualization, knowledge formalization, knowledge realization and knowledge testing, which shaped into uniform cognition and criterion. COM technology was applied into the system realizations, which obtain easily disease and pathogeny. In the last, the research conclusion was used to guide developing fish disease diagnosis expert system for Tianjin city. On the other hand, theory research was deepened in practice.The dissertation' conclusion can be used as reference for the developer to construct diagnosis expert system. It has reference meaning for theory researchers to study diagnosis reasoning.