Journal of Intelligent & Fuzzy Systems - Volume 30, issue 5

Authors: Li, Fenghuan | Zheng, Dequan | Zhao, Tiejun | Pedrycz, Witold

Article Type: Research Article

Abstract: Anomalies are subsequences that exhibit departures from normal state of operation. In this paper, to solve the problems of unknown data distribution, control limit determination, multiple parameters, training data and fuzziness of ‘anomaly’, a self-adaptive and unsupervised model is developed for finding anomalies in data streams. A salient feature is a synergistic combination of both statistical and fuzzy set-based techniques. Anomaly detection problem is viewed as a certain statistical hypothesis testing which is realized in an unsupervised mode. At the same time, ‘anomaly’ is a much more complex concept and as such can be described with fuzzy set theory. Fuzzy …sets bring a facet of robustness to the overall scheme and play an important role in the successive step of hypothesis testing. Because of the fuzzification, parameters determination is self-adaptive and no parameter needs to be specified by the user, what’s more, there is no need to consider the data distribution in statistical hypothesis testing in this paper. The approach is validated with a number of experiments, which help to quantify the performance of constructed algorithm. Show more

Keywords: Anomaly detection, statistical test, self-adaptive, fuzzy set theory, unsupervised

DOI: 10.3233/IFS-151910

Citation: Journal of Intelligent & Fuzzy Systems, vol. 30, no. 5, pp. 2611-2622, 2016

Authors: Gegov, Alexander | Sanders, David | Vatchova, Boriana

Article Type: Research Article

Abstract: This paper proposes a novel approach for modelling complex interconnected systems by means of Mamdani fuzzy networks with feedforward rule bases. The nodes in these networks are rule bases connected in a feedforward manner whereby outputs from some rule bases are fed as inputs to subsequent rule bases. The approach allows any fuzzy network of this type to be presented as an equivalent Mamdani fuzzy system by linguistic composition of its nodes. The composition process makes use of formal models for fuzzy networks, basic operations in such networks, their properties and advanced operations. These models, operations and properties are used …for defining several types of networks with single or multiple horizontal levels and vertical layers. The proposed approach facilitates the understanding of complex interconnected systems by improving the transparency of their models. Show more

Keywords: Fuzzy modelling, decision support systems, finance, linguistic modelling, feedforward connections, complex systems

DOI: 10.3233/IFS-151911

Citation: Journal of Intelligent & Fuzzy Systems, vol. 30, no. 5, pp. 2623-2637, 2016

Authors: Rebiasz, Bogdan

Article Type: Research Article

Abstract: This paper presents the methods of processing interactive data describing different forms of uncertainty. Data can be expressed in the form of interactive possibility distribution or the part of data can be expressed in the form of interactive possibility distribution and the part in the form of probability distribution. The procedure of processing combines stochastic simulation with nonlinear programming or simulation of fuzzy systems. The interaction between data are modeled by the correlation matrices and the interval regression. Presented practical example indicates that an interaction between data have a significant impact on results of calculations. Data processing without consideration of …these interrelations would bear a considerable, systematic error. Show more

Keywords: Data processing, dependence, possibility distribution, fuzzy numbers, random fuzzy numbers

DOI: 10.3233/IFS-151993

Citation: Journal of Intelligent & Fuzzy Systems, vol. 30, no. 5, pp. 2639-2656, 2016

Authors: Çanak, İbrahim

Article Type: Research Article

Abstract: In this paper, we show under which conditions the limit of the distance between nth term of a sequence of fuzzy numbers and nth term of its Cesàro mean of order one tends to zero. As corollaries we prove several Tauberian theorems for Cesàro summability of sequences of fuzzy numbers.

Keywords: Fuzzy numbers, sequences of fuzzy numbers, Cesàro summability

DOI: 10.3233/IFS-151999

Citation: Journal of Intelligent & Fuzzy Systems, vol. 30, no. 5, pp. 2657-2662, 2016

Authors: Hu, Linmin | Su, Peng

Article Type: Research Article

Abstract: A discrete time repairable multi-state series-parallel system with fuzzy data is considered. The lifetimes and the repair times of the system components are assumed to be geometrically distributed random variables with fuzzy parameters, and the performance levels of the system components are presented as fuzzy values. Fuzzy set theory is employed to deal with the uncertain problem of the system. A discrete time fuzzy Markov model is proposed to assess the fuzzy state probability of binary component. The fuzzy universal generating function technique is adopted to evaluate fuzzy state probability and fuzzy performance level of the entire system. An availability …assessment approach is proposed to compute the dynamic fuzzy availability of the system with the fuzzy consumer demand. Based on the extension principle, the α  - cuts of some indices for the system are obtained by using parametric programming technique. Finally, a numerical example is presented. Show more

Keywords: Discrete time, multi-state system, fuzzy availability, fuzzy universal generating function, parametric programming

DOI: 10.3233/IFS-152012

Citation: Journal of Intelligent & Fuzzy Systems, vol. 30, no. 5, pp. 2663-2675, 2016

Authors: Erdem, Hamit | Altinoz, Okkes Tolga

Article Type: Research Article

Abstract: Proportional- Integral (PI) like Fuzzy Logic Controllers (FLC) has been widely used for control of static power converters (SPC). The performance of these controllers is sensitive to controller rules, parameters of membership functions and input-output scaling factors. Among these parameters, scaling factor (SF) directly affects the controller performance in terms of transient response, steady state error and stability. Therefore, using an optimum SF value increases the performance of the FLC against using a constant value. Hence, in this paper optimizing the output scaling factor (OSF) of the PI-like fuzzy logic controller (PIFLC) by using Particle Swarm Optimization (PSO) algorithm is …proposed. In order to optimize and analyze the effect of this parameter on the controller performance, first the output scaling factor of FLC is optimized with various PSO algorithms and one of these algorithms is selected for experimental test. Then optimized FLC is applied to a DC-DC Buck converter, and the performance of the controller is evaluated under nominal load and load disturbance. The controller design, the OSF optimization, and the controller performance analysis approaches are presented in detail. Show more

Keywords: Particle Swarm Optimization, Buck converter, PI like FLC, scaling factor

DOI: 10.3233/IFS-152020

Citation: Journal of Intelligent & Fuzzy Systems, vol. 30, no. 5, pp. 2677-2688, 2016

Authors: Liu, Yun-Zhi | Fan, Zhi-Ping | Gao, Guang-Xin

Article Type: Research Article

Abstract: The linear programming technique for multidimensional analysis of preference (LINMAP) is a representative decision making method with respect to preference information for given alternatives. In the classical LINMAP method, all of the decision data is known precisely or is given as crisp values. It cannot be used to solve the MAGDM problems under the linguistic hesitant fuzzy environment. In this paper, an extended LINMAP method is proposed to solve the MAGDM problems in which all the attribute values of alternatives and the truth degrees of all pair-wise alternatives’ comparisons are in the form of linguistic hesitant fuzzy sets (LHFSs). In …this method, a formula is first presented to calculate the similarity coefficient for the LHFS. On the basis of this, the weight of each expert with respect to each attribute is determined using the support function of the power average (PA) operator. Meanwhile, the collective consistency and inconsistency measurements are introduced to depict the incomplete pair-wise comparison preference relations on alternatives provided by the experts. Then, a linear programming model is constructed to determine the optimal weights of attributes. Furthermore, by calculating the comprehensive ranking values, the ranking of alternatives can be determined. Finally, a numerical example is used to illustrate the use of the proposed method. Show more

Keywords: Linear programming technique for multidimensional analysis of preference (LINMAP), multiple attribute group decision making (MAGDM), linguistic hesitant fuzzy set (LHFS), similarity coefficient

DOI: 10.3233/IFS-152022

Citation: Journal of Intelligent & Fuzzy Systems, vol. 30, no. 5, pp. 2689-2703, 2016

Authors: Cai, Yanyan | Yu, Jin

Article Type: Research Article

Abstract: Evaluation of engineering geological environment and construction of urban layout compose a multi-factors and multi-levels process. How to choose and use condition of engineering geological environment, protect and control the possible engineering geological problem, reduce the occurrence of geological hazard is very important in urban layout. In this paper, we investigate the engineering geological environment comprehensive evaluation with intuitionistic fuzzy information. Motivated by the ideal of dependent aggregation, we shall propose the dependent intuitionistic fuzzy Hamacher weighted average(DIFHWA) operator, in which the associated weights only depend on the aggregated intuitionistic fuzzy arguments and can relieve the influence of unfair arguments …on the aggregated results by assigning low weights to those “false” and “biased” ones and then apply this operator to develop an approach for engineering geological environment comprehensive evaluation with intuitionistic fuzzy numbers. Finally, an illustrative example for engineering geological environment comprehensive evaluation is given to verify the developed approach. Show more

Keywords: Intuitionistic fuzzy information, operational laws, dependent intuitionistic fuzzy Hamacher weighted average(DIFHWA) operator, engineering geological environment comprehensive evaluation

DOI: 10.3233/IFS-152023

Citation: Journal of Intelligent & Fuzzy Systems, vol. 30, no. 5, pp. 2705-2711, 2016

Authors: Beigi, Akram | Mozayani, Nasser

Article Type: Research Article

Abstract: Recently multi agent systems are used to solve complex problems. In these systems agents can cooperate when a problem is difficult or impossible to solve for an individual agent. Via learning, the agents attempt to maximize some of their utilities. In multi agent learning an agent learns to interact with other agents and considering their behaviors. By multi task learning, the agent simultaneously learns a set of related problems and with reinforcement learning, an agent learns a proper policy to achieve its goal. In learning process, using the experience of teammate agents by simple interactions among them is very beneficial. …In this paper we have presented a simple model of agents’ interactions using operators of an evolutionary algorithm. Applying the proposed model has improved significantly the performance of multi task learning in a nondeterministic and dynamic environment, specifically for the dynamic maze problem. The experimental results indicate our claim. Show more

Keywords: Interactions between agents, multi task reinforcement learning, evolutionary algorithms, dynamic environment

DOI: 10.3233/IFS-152024

Citation: Journal of Intelligent & Fuzzy Systems, vol. 30, no. 5, pp. 2713-2726, 2016

Authors: Yu, Dejian | Li, Deng-Feng | Merigó, José M. | Fang, Lincong

Article Type: Research Article

Abstract: The purpose of this study is to identify the current research status on linguistic decision making through visualization method. The effective information visualization tool called CiteSpace was used to dig out how the research of linguistic decision making was conducted. A number of 2017 documents published between 1980 and 2015 were downloaded via Web of Science with the keyword “linguistic decision making ” was used for topic search. The reference co-citation network was mapped to explore the reprehensive documents and research clusters in linguistic decision making area. The author co-citation network was generated to reveal the influential scholars in this …area. The journal co-citation map was formulated to identify the dominant journals. The category network was mapped to excavate the most popular research category in linguistic decision making area. The results of this study have great significance to the researchers in linguistic fuzzy set, linguistic decision making and linguistic group decision making areas. Show more

Keywords: Linguistic decision making, CiteSpace, map, review

DOI: 10.3233/IFS-152026

Citation: Journal of Intelligent & Fuzzy Systems, vol. 30, no. 5, pp. 2727-2736, 2016