Study On Knowledge Representation Of Dam Construction Simulation Integrated With Expert System

Simulation system of dam construction is not only one of the successful applications of system analysis in hydraulic engineering, but also one of the assistant decision tools to the decision-maker. Because of the effect of internal and external factors in the process of construction, dam construction system is complicated, and the model in the system which is used to analysis the process of construction is not all structured model. Common simulation system has some problems in dealing with logic inference, such as low inference efficiency and low readability. With the object-oriented technique, the simulation of dam construction integrated with expert system, establishes the prolog inference engine, improves the efficiency of inference, and the method of knowledge representation based on grammatical rules of prolog enhances the readability of the program.Since the simulation system of dam construction involves many discontinuous activities, it is a discrete system. Time-step and event-step are the two methods of clock pushing in the discrete system. According to the property of construction simulation and the computer performance, it is better to choose time-step as the method of clock pushing. The construction simulation which is achieved with the object-oriented technique is divided into production subsystem, transportation subsystem, placement subsystem.Expert system is different from the common simulation program. It has six parts, among which the inference engine and knowledge base are the most important.Knowledge is the foundation of all of the intelligent actions, so the better method of knowledge representation can improve the efficiency of inference and expression. Considering the inference engine and the property of dam concrete pouring construction, it is better to choose the method of knowledge representation based on grammatical rules of prolog which is the complementation between the predication and the production knowledge representation. The searching-control strategy of backtrack and cut also can improve the inference efficiency.According to the simulation command, the simulation system deals with the logic inference by the inference engine with the facts and rules of the knowledge base, and then feeds back the results, updates the knowledge base. The method of knowledge representation verifies the construction of Xiaowan hydropower project. It is helpful for engineering construction.