This research develops a comprehensive method to solve a combinatorial problem consisting of distribution system reconfiguration, capacitor allocation, and renewable energy resources sizing and siting simultaneously a...This research develops a comprehensive method to solve a combinatorial problem consisting of distribution system reconfiguration, capacitor allocation, and renewable energy resources sizing and siting simultaneously and to improve power system's accountability and system performance parameters. Due to finding solution which is closer to realistic characteristics, load forecasting, market price errors and the uncertainties related to the variable output power of wind based DG units are put in consideration. This work employs NSGA-II accompanied by the fuzzy set theory to solve the aforementioned multi-objective problem. The proposed scheme finally leads to a solution with a minimum voltage deviation, a maximum voltage stability, lower amount of pollutant and lower cost. The cost includes the installation costs of new equipment, reconfiguration costs, power loss cost, reliability cost, cost of energy purchased from power market, upgrade costs of lines and operation and maintenance costs of DGs. Therefore, the proposed methodology improves power quality, reliability and security in lower costs besides its preserve, with the operational indices of power distribution networks in acceptable level. To validate the proposed methodology's usefulness, it was applied on the IEEE 33-bus distribution system then the outcomes were compared with initial configuration.展开更多
Choosing a strategy for sustainable development is national level aimed at the simultaneous fulfillment of economic, a fundamental problem that requires non-trivial approaches at the social and environmental goals. Th...Choosing a strategy for sustainable development is national level aimed at the simultaneous fulfillment of economic, a fundamental problem that requires non-trivial approaches at the social and environmental goals. This contradiction is possible to be adequately described in the complex game-theoretic models. But analysis of them is complicated by the problems of algorithmic solvability and the payoff functions construction. Also, the volume of data required creates considerable complexity increased by the conditions of situations uncertainty and conflict. At the same time, international organizations, such as UN （United Nations）, ITU （International Telecommunications Union）, are widely used index system. Indices, built on the aggregation of elementary indicators, allow the estimation of the components of the system and its overall development. The paper discusses the basic concepts of game-theoretic approach to the problems of finding strategies for sustainable development, using indicative analysis techniques. In the proposed approach, estimating of sustainability is considered as the result of finding the optimal values of the payoff functions in general game-theoretical model where the players are matched indices. The interests of the player are to increase of the corresponding index and the optimal situation is implemented as a set of optimal payoff functions values. This allows switching from processing of large amounts of data describing the behavior of the ecological-economic system by the aid of indicators to aggregate estimations, which significantly reduce the sample, and also facilitates the interpretation of the results.展开更多
Due to the uncertainty of the factors that influence the network service time and other characters of college student, Bayesian Network is used to model this kind of system. Different algorithms are used for learning ...Due to the uncertainty of the factors that influence the network service time and other characters of college student, Bayesian Network is used to model this kind of system. Different algorithms are used for learning Bayesian Networks in order to compare several models. It is suggested that researchers can use Bayesian Networks to explore the potential relationship between variables of complex social problems. The result indicates that learning target and family closeness degree are the key variables which influenced college student＇ s network service time. Origin of student and family economy didn＇ t influence college student＇ s network service time directly. Schools and community should strengthen the education of college students life planning and communication with parents.展开更多
文摘This research develops a comprehensive method to solve a combinatorial problem consisting of distribution system reconfiguration, capacitor allocation, and renewable energy resources sizing and siting simultaneously and to improve power system's accountability and system performance parameters. Due to finding solution which is closer to realistic characteristics, load forecasting, market price errors and the uncertainties related to the variable output power of wind based DG units are put in consideration. This work employs NSGA-II accompanied by the fuzzy set theory to solve the aforementioned multi-objective problem. The proposed scheme finally leads to a solution with a minimum voltage deviation, a maximum voltage stability, lower amount of pollutant and lower cost. The cost includes the installation costs of new equipment, reconfiguration costs, power loss cost, reliability cost, cost of energy purchased from power market, upgrade costs of lines and operation and maintenance costs of DGs. Therefore, the proposed methodology improves power quality, reliability and security in lower costs besides its preserve, with the operational indices of power distribution networks in acceptable level. To validate the proposed methodology's usefulness, it was applied on the IEEE 33-bus distribution system then the outcomes were compared with initial configuration.
文摘Choosing a strategy for sustainable development is national level aimed at the simultaneous fulfillment of economic, a fundamental problem that requires non-trivial approaches at the social and environmental goals. This contradiction is possible to be adequately described in the complex game-theoretic models. But analysis of them is complicated by the problems of algorithmic solvability and the payoff functions construction. Also, the volume of data required creates considerable complexity increased by the conditions of situations uncertainty and conflict. At the same time, international organizations, such as UN （United Nations）, ITU （International Telecommunications Union）, are widely used index system. Indices, built on the aggregation of elementary indicators, allow the estimation of the components of the system and its overall development. The paper discusses the basic concepts of game-theoretic approach to the problems of finding strategies for sustainable development, using indicative analysis techniques. In the proposed approach, estimating of sustainability is considered as the result of finding the optimal values of the payoff functions in general game-theoretical model where the players are matched indices. The interests of the player are to increase of the corresponding index and the optimal situation is implemented as a set of optimal payoff functions values. This allows switching from processing of large amounts of data describing the behavior of the ecological-economic system by the aid of indicators to aggregate estimations, which significantly reduce the sample, and also facilitates the interpretation of the results.
文摘Due to the uncertainty of the factors that influence the network service time and other characters of college student, Bayesian Network is used to model this kind of system. Different algorithms are used for learning Bayesian Networks in order to compare several models. It is suggested that researchers can use Bayesian Networks to explore the potential relationship between variables of complex social problems. The result indicates that learning target and family closeness degree are the key variables which influenced college student＇ s network service time. Origin of student and family economy didn＇ t influence college student＇ s network service time directly. Schools and community should strengthen the education of college students life planning and communication with parents.
