Research On Structure Model And Evolution Of Emergency System Based On Knowledge Element

Witn economic growth and social development, human beings encounter increasing degradation in the environment for survival. Various emergencies derived from natural and accidental disasters, along with those combined, have had severe threats on human society and its harmonious development. Given the variety of the emergencies, they present great differences in their respective features. With different situation and association in between, the same event may present different evolving paths. In the course of answering the emergency, the managers may be faced with plenty of multi-sourced heterogeneous information, and have to identify the development trend and evolving direction in a comprehensive and integral perspective, followed by a rapid and scientific decision-making based on incomplete supporting information. It is helpful for the emergency managers to understand the hierarchical constitution and evolving laws of emergencies by summarizing their general rules, thus is a better cognition of their evolving process and a response in time.Researchers at home and abroad have studied the evolving laws of emergencies in certain categories, ranging from natural disasters to accidents, public health incidents, social security events, to name a few, but few regard the emergency and its circumstances as a complex system to look into their systematically constitutional features and evolving laws in generality. In the perspective of knowledge, the knowledge source has nothing to do with the knowledge in specific field, which makes it possible to constitute the general structure model of the emergency system by means of describing the general features of various elements in the system. How to analyze emergency systems with different features? How to make use of the existing knowledge and its management models to find out the general features and evolving laws of various emergencies, and make them expressed in a scientific and unified way? It is essential for such questions to be answered in the management of emergencies.Under the above background, this thesis is to establish the modal of knowledge elements in events and hazard bearing body of the emergency system by the conceptualization of emergency and the analysis of its system. Based on the modal of knowledge element, the changing processes of the general structure and the system entropy of the emergency system are to be analyzed, followed by the identification of the general law of the system evolution. According to the knowledge element of the event, the prediction method for risk entropy of the emergency is to be offered. The details are as follows:(1) The concept of the emergency is defined from the source of its occurrence by regarding emergencies and their circumstances as a complicated system, followed by the analysis of the system’s composition and the establishment of its event knowledge element and hazard bearing body knowledge element. The general structure of the emergency system is analyzed, with format description of various levels and the setting of the general structure modal of the emergency system based on knowledge element. The temporal and spatial domains of the emergency evolution is segmented, thus is the analysis of its characters in dissipative structure and the disclosure of its essence in occurrence, evolution and objective foundation.(2) The entropy phenomenon inside the emergency system is explained in details by putting forward the concept of emergency system entropy to reveal the disorder degree inside the system, which is composed of the positive and negative entropies provided respectively by environmental input feature set and emergency response output feature set of the event knowledge element entity in the system. Following the analysis of the evolving process of the system entropy is the induction of the entropy’s accumulative, mutation and declining periods from the system entropy evolution. With the application of catastrophe theory, the mutation modal of the emergency system entropy is established based on knowledge element. After getting the changing conditions’of the system entropy, the thesis confirms the parameter domain of the system entropy’s stable status. It is revealed that emergency system entropy evolves in two forms, namely, gradual and sudden changes, with four paths of lagging mutation, leading mutation, synchronous gradual stabilization and asynchronous instability.(3) Given such challenges as many influencing factors in the course of emergency evolution, and the difficulty in quantitative description of the risk entropy derived from few on-site observation data and multiple dimensions, this thesis puts forward the emergency risk entropy prediction methodology based on knowledge element. By means of projection pursuit, the multi-element observation and measurement data is de-dimensioned, thus is the acquirement of the projected characteristic value from the multi-dimension input feature set of the subject in the event knowledge element, based on which data characteristics of the multi-elements are reflected by single elements. By means of information diffusion theory, the single element’s projected characteristic value of the input feature set is spread to the control point of output feature’s risk index discourse domain, thus is the acquirement of emergency occurrence probability at different risk levels. By means of information entropy theory, emergency risk entropy calculating method is provided, thus is the prediction of emergency occurrence possibility.(4) With reference to the sudden freezing rain and snow event system (SURSES) of China in2008, Changsha City in Hunan Province of China is chosen as the case study area to test the formation method of the SURSES and the risk entropy prediction process of sudden freezing rain and snow events. The case analysis results present that the general structure model of emergency system based on knowledge element put forward by this study is more convenient to be used in describing emergency occurrence law and the evolving rules at different levels. The risk entropy prediction method based on knowledge element can predict the risk entropy according to the time series of the sample. The changing trend of the risk entropy coincides with the rules of the entropy change.Based on knowledge element, this study systematically analyzes the general structure of emergency system, discusses the evolving rules of the system entropy, puts forward the prediction methodology of emergency risk entropy, and provides theoretical and practical reference for emergency response management.