Fuzzy Information and Engineering

Nasrabadi, Mohammad Mehdi; Yaghoobi, Mohammad Ali; Mashinchi, Mashaallah

2010 Fuzzy Information and Engineering

doi: 10.1007/s12543-010-0034-9

AbstractThis paper discusses a class of continuous linear programs with fuzzy valued objective functions. A member of this class is called a fuzzy separated continuous linear program (FSCLP). Such problems have applications in a number of domains, including, production and inventory systems, communication networks, and pipeline systems for transportation. The discretization approach is used to construct two ordinary fuzzy linear programming problems, which give a lower and an upper bound on the optimal value of FSCLP. It is then shown how to construct an improved feasible solution for FSCLP starting from a nonoptimal one. This leads to the development of a class of algorithms based on a sequence of discrete approximations to FSCLP. Numerical examples in the context of continuous-time networks are presented to show the applicability of the proposed method.

Wang, Zhong-xing; Mo, Ya-ni

2010 Fuzzy Information and Engineering

doi: 10.1007/s12543-010-0035-8

AbstractIn this paper, we consider the factor of the decision maker's risk preference, and define the left and right deviation degree respectively. Besides, we propose a new formula of the fuzzy degree. Then we get the multiattribute matrix of fuzzy numbers. We rank fuzzy numbers with the help of an ideal solution. Some numerical examples are displayed to illustrate the validity and advantages of the proposed ranking method.

Kumar, Amit; Singh, Pushpinder; Kaur, Amarpreet; Kaur, Parmpreet

2010 Fuzzy Information and Engineering

doi: 10.1007/s12543-010-0036-7

AbstractRanking of fuzzy numbers play an important role in decision making, optimization and forecasting etc. Fuzzy numbers must be ranked before an action is taken by a decision maker. In this paper, with the help of several counter examples, it is proved that ranking method proposed by Chen and Chen (Expert Systems with Applications 36(3): 6833) is incorrect. The main aim of this paper is to propose a new approach for the ranking of generalized trapezoidal fuzzy numbers. The proposed ranking approach is based on rank and mode so it is named as an RM approach. The main advantage of the proposed approach is that the proposed approach provides the correct ordering of generalized and normal trapezoidal fuzzy numbers and also the proposed approach is very simple and easy to apply in the real life problems. It is shown that proposed ranking function satisfies all the reasonable properties of fuzzy quantities proposed by Wang and Kerre (Fuzzy Sets and Systems 118(3): 375).

Hafaifa, Ahmed; Laroussi, Kouider; Laaouad, Ferhat

2010 Fuzzy Information and Engineering

doi: 10.1007/s12543-010-0037-6

AbstractThis work presents the results of applying an advanced fault detection and isolation technique to centrifugal compressor; this advanced technique uses physics models of the centrifugal compressor with a fuzzy modeling and control solution method. The fuzzy fault detection and isolation has become an issue of primary importance in modern process engineering automation as it provides the prerequisites for the task of fault detection. In this work, we present an application of this approach in fault detection and isolation of surge in compression system. The ability to detect the surge is essential to improve reliability and security of the gas compressor plants. We describe and illustrate an alternative implementation to the compression systems supervision task using the basic principles of fuzzy fault detection and isolation associated with fuzzy modeling approach. In this supervision task, the residual generation is obtained from the real input-output data process and the residual evaluation is based on fuzzy logic method. The results of this application are very encouraging with relatively low levels of false alarms and obtaining a good limitation of surge in natural gas pipeline compressors.

Xian, Si-dong

2010 Fuzzy Information and Engineering

doi: 10.1007/s12543-010-0038-5

AbstractIn this paper, focused on a proper weight distribution vector of a fuzzy comprehensive evaluation method, a new fuzzy comprehensive evaluation model based on the supper vector machine (SVM) is proposed for overcoming the subjective limitation in traditional fuzzy comprehensive evaluation model. Furthermore, a multilevel fuzzy comprehensive evaluation model based on SVM of network learning has also been designed, and the improved algorithm is used to make an instant computation. This method gives good performance on determination of the weight distribution vector and improves the evaluation accuracy and generalization with an example.

Song, Chong-zhi; Zhao, You-qun

2010 Fuzzy Information and Engineering

doi: 10.1007/s12543-010-0039-4

AbstractThe paper proposed a systematic and effective optimization process to optimize a 3-D vehicle suspension dynamic model with eight DOF, including seat vertical motion, suspension vertical, pitching and rolling motions and wheels vertical motions using fuzzy optimization, to attain the best compromise between ride comfort and vehicle-generated road damage. The results show a substantial improvement in the vertical ride quality is obtained while keeping the suspension deflections within their allowable clearance when the vehicle moves at a constant velocity v = 20m/s, and the comfort performance of a suspension seat can be considerably enhanced.

Yang, Ji-hui; Cao, Bing-yuan

2010 Fuzzy Information and Engineering

doi: 10.1007/s12543-010-0040-y

AbstractFuzzy geometric programming (GP) is an important optimization type. In this paper, first the origin of fuzzy GP is introduced, some recent research findings of its theory have been summarized. Then a lot of progress achieved in application is introduced in fuzzy GP, including applications in power system, environmental engineering, economic management, etc. The range of its application expects to be further expanded. Besides, as a branch of fuzzy GP, the fuzzy relation GP, rough (extension) and grey one have also been mentioned. Finally, the new research direction of fuzzy GP will be put forward.