The Research On Theory And Algorithm Of Causality Diagram Of Complex System

Complex System (CS) is a system composed of mass interacting units. The Complexity science which is honored as a 21st century science by scientists, is gradually understood and accepted by people, and a group of scholars both at home and abroad has conducted researches in the field. In April, 1994, the SCIENCE—an America journal has published a special issue entitled Complexity System, which focused on the complex system and its content covered physics, chemistry, biology, economics, ecology, geography, meteorology, neuroscience, etc. At home, a group of scientists, led by professor Qian Xue-sen, apply themselves to study Complex System. Complex System comprises many subsystems. It has the following characteristics: integrity, systematization, opening, complexity, hierarchy, dynamic, and uncertainty.Fault diagnosis of Complex System is an important application of artificial intelligence (AI) to practical problem. Nowadays the system is so complex, which complicates fault diagnoses. It becomes very important to study how to ensure that the modern industrial complex system runs safely and reliably. Fault diagnosis of complex system has such characteristics as hierarchy, timeliness, delay, relativity, fuzziness, randomicity, uncertainty, radioactivity, etc.With the persistent development of AI technology, Intelligent Diagnosis System (IDS) has played a more and more important role in the field of fault diagnosis. The representation and reasoning methodology dealing with uncertainty knowledge, which is an important, core and difficult problem of AI, has always been an international research hotspot because of its realistic significance. Dynamic Causality Diagram (DCD) is an uncertainty reasoning method proposed by professor Zhang Qin in 1994. The Causality Diagram (CD) which is constituted by experts, thanks to its reasoning capability (forward reasoning, backward reasoning and bi-directional reasoning), can thus diagnose faults in complex system.This paper discusses the Dynamic Causality Diagram and its application in complex system, focuses on the reasoning theory and algorithm of causality diagram of complex system (CDCS). Its content mainly involves fuzzy causality diagram (FCD), dynamic reasoning of CD, reasoning algorithm of CDCS, and the application CD in complex system. Based on the fuzziness, timeliness, dynamic, and relativity, this paper respectively puts forward the theory and algorithm of FCD, iterative reasoning...