32437026
Fuzzy Comprehensive Evaluation for Power Network Operating Schemes
Based on the analytic hierarchy process, a fuzzy comprehensive evaluation method is proposed for power network operating schemes. Performance indices and corresponding membership functions are presented to denote their contributions on overall objective. The analytic hierarchy process is used to analyze influencing factors, to establish a hierarchical model and to rank the influencing factors in order of importance. After detailed analyses and calculations for each operating scheme, quantitative evaluation results that considering various factors comprehensively are obtained by a two-level fuzzy comprehensive evaluation. A decision support system using the proposed method is developed. Simulation results of a practical power system show its validity and effectiveness.
42648138
Fuzzy Comprehensive Evaluation for Electromagnetic Loop in China Ultra-high Voltage Grid
In initial period of ultra-high voltage grid, 1000kV/500kV loops, perhaps even 1000kV/500kV/ 220kV loops, will turn up. The hazards caused by electromagnetic loop are discussed from two sides involving power transfer and short-circuit current level. Multi-level electromagnetic loop of North and Central China power grid in the planning year 2010 are analyzed. A method combining analytic hierarchy process with fuzzy logic theory is employed to comprehensively evaluate opening schemes for electromagnetic loop. Evaluation results indicate that multi-level electromagnetic loops should be avoided by opening extra-high/high voltage loops promptly. Furthermore, it’s also necessary to open ultra-high/extra-high voltage loops reasonably.
1064501
Trade-off scheme for fault tolerant connected dominating sets on size and diameter
Connected Dominating Set (CDS) has been a well known approach for constructing a virtual backbone to alleviate the broadcasting storm in wireless networks. Current research has focused on minimizing the size and diameter or improving the fault tolerance of CDS. However, to our best knowledge, no existing research has considered these three important factors together in a single model. In this paper, we introduce the fault tolerant model studying a joint optimization problem in which the objective is to minimize the CDS size as well as the network latency. This model also addresses the tradeoffs between the objective functions. We next propose one approximation algorithm and two distributed algorithms with constant ratios for the model. Simulation results show that our algorithms can gain good tradeoffs between the three factors, which coincide with theoretical analysis. Moreover, our algorithms could obtain a better performance than previous work.
10813806
An efficient protocol for anonymous and fair document exchange
Fairness in document exchange has been well studied, while anonymity in the exchange, which protects the privacy of personal information such as identities and locations, has been either ignored or handled with partial or inappropriate considerations. In this paper we propose a new protocol for anonymous and fair document exchange between two parties with the assistance of an off-line trusted third party. The new protocol treats both fairness and anonymity as essential properties, employs an efficient method for off-line key recovery, and places weak requirements on the security of the third party.
11711753
CRM Method for Power Supply Enterprises Based on Analysis of Utility and Customers_ Credit and Multistage Fuzzy Evaluation
As the major customers can choose power supply enterprises independently in electric power marketplace, the enterprises are forced to have to implement CRM, abbreviation for customer relationship management which is an important method of controlling the major customers to prevent their loss. While, in order to making the implementation of CRM more effectively, a problem on how to make a choice of the stimulation method depending on the need of electricity customers needs to be resolved by electricity power supply enterprises. This paper is on the basis of utility theory and multistage fuzzy evaluation, classifying major customers by analyzing and evaluating the level of the customers' credit and the utility of different stimulation methods on different electricity customers, and putting forward the stimulation method for the electricity power supply enterprises to implement CRM. At the end of this paper, this method is confirmed to be reasonable with a simulation example.
17853419
A succinct physical storage scheme for efficient evaluation of path queries in XML
Path expressions are ubiquitous in XML processing languages. Existing approaches evaluate a path expression by selecting nodes that satisfies the tag-name and value constraints and then joining them according to the structural constraints. We propose a novel approach, next-of-kin (NoK) pattern matching, to speed up the node-selection step, and to reduce the join size significantly in the second step. To efficiently perform NoK pattern matching, we also propose a succinct XML physical storage scheme that is adaptive to updates and streaming XML as well. Our performance results demonstrate that the proposed storage scheme and path evaluation algorithm is highly efficient and outperforms the other tested systems in most cases.
36066337
H2 Control design for fuzzy dynamic systems via LMI
This paper addresses the robust H_2 control design of complex nonlinear systems which can be represented by a fuzzy dynamic model. Based on a continuous Lyapunov function and a piecewise continuous Lyapunov function respectively, two kinds of new control design methods are proposed using Lyapunov stability theory, robust H_2 control theory and Linear Matrix Inequalities (LMI) techniques. It is shown that the closed loop fuzzy control system is asymptotically stable with a white noise attenuation. The robust H_2 fuzzy controller can be obtained by using the LMI techniques. An example is given to demonstrate the application of the proposed design methods.