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Study On Engineering Fuzzy Set Theory And Their Applications In Water Resources System

Posted on:2006-05-26Degree:DoctorType:Dissertation
Country:ChinaCandidate:X F YuFull Text:PDF
GTID:1102360152485477Subject:Water Resources and Hydropower Engineering
Abstract/Summary:PDF Full Text Request
The world's fresh water is one of the most important resources known to mankind, and water resource system is the most important component of the nature , society system as well as ecology and environment systems, it has close relationship with economy development and eco-environment movement. Fresh water available for human consumption, for social, economic and cultural needs and for environmental requirements is rapidly becoming scarcer, as we enter the 21st century, water shortages throughout the world continue to multiply at an unprecedented rate. The principle of integrated water resources sustainable utilizing management was developed and received widely acceptance in the world. The sustainable utilizing water resources management emphasizes that thinking in terms of economic costs and benefits is no longer sufficient; social, cultural, and environmental aspects have to be incorporated into the decision-making process, especially with regard to long-term effects.In real world, water resources system is a multi-objective, multi-utility, multi-layer, multi-phrase complex system. There are not only quantitative objectives but also qualitative objectives. So the methodology of water resource analysis should integrate quantitative analysis and qualitative analysis, structural analysis and non-structural analysis. This doctoral thesis does some researches on the application of Engineering Fuzzy Set Theory (EFST) established by Prof. Chen Shouyu in water resource system, the main points are as follows:1. Researches on Fuzzy Recognition Model and its propertyAccording to fuzzy set theory established by Prof. Chen Shouyu, the author proposesobjective function min and deduces two-level fuzzy pattern recognitionmodel, which is similar to ideal solution method (TOPSIS), as well as the prove of 3 properties of the model. The properties can make the model easy to be used.2. The applications of fuzzy cluster iterative model in water resources systemThere arise problems in specimen recognition without standard partition, such as the match of water resources space-time distribution and society, economy development, etc. In order to deal with these problems, Prof. Chen Shouyu established fuzzy cluster iteration model (FCIM) in the researching of fuzzy set theory, In this paper, with the model, the relative membership grades (RMG) of the classes can be calculated and taken as the weights of the classes, so the rand of objects can be obtained by the comparison of the RMG of each object. The applications of FCIM include: (1) combining water resources and productivity distribution, the author analysis the space-time distribution of water resource in China. The results show that this model well describes the water resources characteristic of our country. (2) studying on the classification of flood disaster grade, we obtain the disaster degree ofeach province or autonomous region and rank order of "98" flood disaster in China. The case shows us that the FCIM makes the clustering of objects have more comparability, and gets more accurate classification results. Which make FCIM more practicable in water resources analysis.3. The applications of EFST in water resources coordination developmentThe principles of water resource sustainable development management are justice, harmony and sustainable. Based on the EFST, the paper studies the harmony of water resources systems: the harmony of one sub-system to the others, or to the general system. Using this method we can assess the sustainable development utilization level of general water resource system, the case study of HanZHong district water resource system utilization level assessment shows the feasibility of this method.4. The applications of equilibrium coefficient of subjective and objective weight in water resource systemEquilibrium coefficient of subjective and objective weight is one of weight decision making method, with which EFST is used in the paper for water resource management. First, we determine the subjective weight, objective weight as well as their weight, then establish an objective function to reach the equilibrium coefficient of subjective and objective weight and the fuzzy recognition iteration model involved Subjective and objective weight. Thereby we can obtain the solution to the objective weight vector. If this weight vector dose not satisfies decision maker's experiential judgments and preference; we should adjust this weight vector according to equilibrium coefficient of subjective and objective weight. The cases study of region water resources sustainable evaluation and flood control object weight determination illustrates the application of subjective and objective weight equilibrium coefficient.5. The applications of fuzzy optimization dynamic programming for regional water resource harmony developmentDynamic programming is the effective method to solve multi-phase optimization that is widely used in water resources planning and optimization. Regarding complex water resources system, there are not only quantitative objective but also subjective objective that involve experts' experience and judgments, so it belongs to semi-structural fuzzy decision making problem. In order to solve this problem, this section integrates fuzzy recognition dynamic programming established by Prof. Chen and water resources harmony analysis detailed in chapter 4 that discuss water right assignment model of water resources system. The method...
Keywords/Search Tags:water resources, sustainable utilization, relationship degree, fuzzy recognition, weight, harmony, linear programming, dynamic programming
PDF Full Text Request
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