Journal of Intelligent & Fuzzy Systems - Volume 27, issue 5

Authors: Ebrahimnejad, Ali | Verdegay, Jose Luis

Article Type: Research Article

Abstract: In recent years various attempts have been made to study the solution of fuzzy variable linear programming problems by introducing and solving certain auxiliary problems or directly by the use of dual simplex method based on a certain linear ranking function. But these methods are not applicable for situations in which some or all variables are restricted to lie within fuzzy lower and fuzzy upper bounds. In this paper, as a natural extension of the results in crisp linear programming and based on a certain linear ranking function we obtain some new results leading to a new method to overcome …this shortcoming. To show the application of our method a real life problem is solved by using the proposed method. Also, one application of this approach in solving maximum flow problem with fuzzy capacity is dealt with. Show more

Keywords: Bounded linear programming, fuzzy linear programming, fuzzy ordering, trapezoidal fuzzy numbers

DOI: 10.3233/IFS-141190

Citation: Journal of Intelligent & Fuzzy Systems, vol. 27, no. 5, pp. 2265-2280, 2014

Authors: Ma, Zhen Ming

Article Type: Research Article

Abstract: (Generalized) fuzzy filters in logical algebras were extensively researched. In this paper, associated with the notion of tip-extended pair of fuzzy sets, it is proved, respectively, that the sets of all fuzzy filters and all generalized fuzzy filters form bounded distributive lattices.

Keywords: Residuated lattice, bounded distributive lattice, fuzzy filter, generalized fuzzy filter

DOI: 10.3233/IFS-141191

Citation: Journal of Intelligent & Fuzzy Systems, vol. 27, no. 5, pp. 2281-2287, 2014

Authors: Nejad, Hadi Chahkandi | Khayat, Omid | Azadbakht, Bakhtiar | Mohammadi, Mohammad

Article Type: Research Article

Abstract: A feed forward neural network for classification of the Electrocardiogram (ECG) beats is employed in this paper. The classification is performed based on a feature extraction scheme. Six groups of ECG beats (MIT-BIH Normal Sinus rhythm, BIDMC congestive heart failure, CU ventricular tachyarrhythmia, MIT-BIH atrial fibrillation, MIT-BIH Malignant Ventricular Arrhythmia and MIT-BIH Supraventricular Arrhythmia) are characterized by the six chaotic parameters including the largest Lyapunov exponent and average of the Lyapunov spectrum (related to the chaoticity of the signal), time lag and embedding dimension (related to the phase space reconstruction) and correlation dimension and approximate entropy of the signal (related …to the complexity of the signal). Nine different structures of the feed forward neural network (in terms of the hidden neurons and the number of learning epochs) were employed to perform the ECG beats classification based on all extracted features for three lengths of the signals. The effects of signals length and FFNN structural parameters are studied in the experiments. It is shown that a minimum length is required for valid signal characterization and also it is shown that how accurate the trained feed forward neural network can discriminate the signals of ECG beats for different arrhythmia behaviors. Some conclusions are made and they are discussed at the end of the paper. Show more

Keywords: ECG beats classification, chaotic feature extraction, feed forward neural network, classification, statistical parameters

DOI: 10.3233/IFS-141192

Citation: Journal of Intelligent & Fuzzy Systems, vol. 27, no. 5, pp. 2289-2296, 2014

Authors: Nejad, Hadi Chahkandi | Azadbakht, Bakhtiar | Adenihvand, Karim | Mohammadi, Mohammad | Mirzamohammad, Mahsa

Article Type: Research Article

Abstract: Diabetic retinopathy is one of the most important causes of visual impairment. In this paper, a supervised automatic lesion detection in digital retina images for diagnosis and screening purposes. The aim of this study is to present a supervised approach for exudate detection in fundus images and also to analyze the method to find the optimum structure. Cellular automata model is used as the base for this task. To improve the adaptability and efficiency of the cellular automata, the rules are updating by a learning process to produce the cellular learning automata. Then, the algorithm is transferred to fuzzy domain …for the task of digital retina image analysis. Automaton is created with simple and extended Moore neighborhood. Rule selection and rule updating are performed automatically and the score and penalty assignments are applied to the cells toward a segmentation process. To evaluate the proposed method, statistical parameters of sensitivity, specificity and accuracy are used. A comprehensive experiment is then executed comprising two main phases. First all structural parameters of the automaton are optimized in an investigation study and then a comparison is made between the proposed method with six other well-known methods to verify the results. In the best structure the statistical parameters of sensitivity, specificity and accuracy are computed as 96.3%, 98.7% and 96.1% for STARE retina image dataset. Show more

Keywords: Retina image, exudates and lesions, fuzzy concept, cellular learning automata, statistical parameters

DOI: 10.3233/IFS-141194

Citation: Journal of Intelligent & Fuzzy Systems, vol. 27, no. 5, pp. 2297-2303, 2014

Authors: Mishra, K.K. | Tiwari, Shailesh | Misra, A.K.

Article Type: Research Article

Abstract: An Environmental Adaption Method (EAM) has been recently proposed in which, each solution updates its structure on the basis of current environmental fitness and its own fitness. EAM uses a new operator known as adaption operator. In this paper, an improved EAM, henceforth called as IEAM has been proposed and proper tuning of parameters of algorithm has been done to find the optimal solution in minimum time. IEAM has been tested on a set of benchmark functions. Results show the superiority of IEAM over PSO-TVAC, SADE and other optimization algorithms. Even for complex functions, the performance of IEAM is very …good. In addition to this, IEAM has also been applied to software testing to generate test cases for white box testing. Show more

Keywords: Evolutionary computing, improved EAM, PSO

DOI: 10.3233/IFS-141195

Citation: Journal of Intelligent & Fuzzy Systems, vol. 27, no. 5, pp. 2305-2317, 2014

Authors: Sartorius, Aldo R. | de Jesús Moreno, José | Piñón, Oscar | Ruiz, Ana Estela

Article Type: Research Article

Abstract: In fuzzy controllers, the adjusting of scale factors, both input and output, is critical to the performance of the plant being controlled. The adjustment of scale factors in Fuzzy PD+I controllers (FPD+I) is well documented; however, in systems that have control signal saturation, FPD+I requires anti-windup systems (AW) that limit the controller's integral action. The adjustment procedure for FPD+I controllers cannot be used in Fuzzy PD+I controllers with anti-windup system (FPD+I AW), as it increases the overall gain system, which causes oscillatory behaviour and even critical stability in the controlled variable. The main motivation of this research was to have …an approach for adjusting Fuzzy PD+I controllers with anti-windup system (FPD+I AW) without having oscillatory behaviour. In order to verify the proposed approach, both the input and output scale factors of a FPD+I AW controller were adjusted and used to control speed in a direct current motor with control signal saturation and were compared with the responses of conventional PID, Adaptive Neuro Fuzzy Inference System (ANFIS) and Fuzzy sliding controllers, all with AWs based on tracking back calculation, thereby demonstrating the effectiveness of the proposed approach. Show more

Keywords: Anti-windup, controller, fuzzy, scaling factor

DOI: 10.3233/IFS-141196

Citation: Journal of Intelligent & Fuzzy Systems, vol. 27, no. 5, pp. 2319-2326, 2014

Authors: Khamseh, Alireza Arshadi | Soleimani, Fariba | Naderi, Bahman

Article Type: Research Article

Abstract: This paper analyzes the pricing decisions of complementary products in a fuzzy supply chain with two manufacturers and one common retailer. Four pricing models, including centralized decision model, MS-Bertrand, RS-Bertrand and NG models, with consideration of different market power structures are adopted. Both the manufacturing cost and the customer demand for products are considered as fuzzy variables. Optimal decisions on prices are determined by using game theoretical approach for each model. Finally, a numerical example is solved to illustrate the effectiveness of each model.

Keywords: Pricing decisions, complementary products, game theory, fuzzy environment

DOI: 10.3233/IFS-141202

Citation: Journal of Intelligent & Fuzzy Systems, vol. 27, no. 5, pp. 2327-2340, 2014

Authors: Liao, Huchang | Xu, Zeshui

Article Type: Research Article

Abstract: The intuitionistic fuzzy preference relation (IFPR), whose elements are intuitionistic fuzzy values, is a powerful structure in expressing the comprehensive preference information of a person. In this paper, after reviewing different kinds of consistency for IFPR, we construct a mathematical model to derive the underlying crisp weighting vector from a multiplicative consistent IFPR. Such method is very easy to be understood. As to multiplicative inconsistent IFPR, we claim that there are two ways to repair it, which are interactive method and automatic method. When the expert does not want to interact with the analyst, or if the analyst cannot find …the initial expert to re-evaluate and alter his/her preferences, or if consistency must be urgently obtained, the proposed automatic algorithm is efficient and useful. Finally, we propose a procedure for group decision making with IFPRs based on the multiplicative consistency of IFPRs. It is proven that if all individual IFPRs are multiplicative consistent, their overall IFPR fused by IFWG operator is also multiplicative consistent. Some numerical examples are given to illustrate the validity and applicability of the proposed methods. Show more

Keywords: Group decision making, intuitionistic fuzzy preference relation, multiplicative consistency

DOI: 10.3233/IFS-141203

Citation: Journal of Intelligent & Fuzzy Systems, vol. 27, no. 5, pp. 2341-2353, 2014

Authors: Baykasoğlu, Adil | Maral, Sultan

Article Type: Research Article

Abstract: Fuzzy rule base systems which were originally proposed by Zadeh are one of the most influential approaches with many practical applications in the literature. On the other hand fuzzy rule bases remain incapable for many practical problems due to the dependence of expert knowledge and complexity of operators utilized. Fuzzy functions concept which was first introduced by Türkşen in 2004 and further enhanced by him and his colleagues provide an alternative to fuzzy rule bases. This approach is not depended on expert knowledge where data is available. In their studies Türkşen and his colleagues generally used Least Square Estimation (LSE) …and Support Vector machines (SVM) in generating fuzzy functions. In the present study, we employed genetic programming approach in order to generate fuzzy functions with better prediction ability. We tested the proposed approach on several benchmark problems with very promising results. In the present paper results of four example applications are reported and results were discussed. It is shown that genetic programming approach considerable improved the prediction ability of fuzzy functions approach. Show more

Keywords: Fuzzy functions, genetic programming, prediction

DOI: 10.3233/IFS-141205

Citation: Journal of Intelligent & Fuzzy Systems, vol. 27, no. 5, pp. 2355-2364, 2014

Authors: Tsakiris, George | Spiliotis, Mike

Article Type: Research Article

Abstract: The failure of an embankment dam results in an outflow hydrograph with catastrophic consequences to the downstream valley, especially when populations at risk are located close to the dam. The estimation of the outflow from the created breach is the key information for delineating the area at risk and the estimation of the associated potential consequences. This paper studies the uncertainty of breach parameter estimations by using fuzzy set theory and its impact on the outflow from the breach. For simulating the breach formation and the development of outflow hydrograph, a simplified analytical solver, which was recently presented by the …authors, is used. The solver is based on the assumptions of prismatic reservoir, the parabolic shape of the breach and the constant rate of vertical erosion. The parameters, which are represented as triangular fuzzy numbers, are: (i) the characteristic parameter of the parabolic shape of the breach and (ii) the rate of vertical erosion. It was concluded that the approach for estimating the outflow differs, depending on the cause of fuzziness. The approach for estimating the outflow differs according to the parameter which exhibits fuzziness in its estimation. In fact, the uncertainty of outflow is to a great extent dependent on the uncertainty of estimation of vertical erosion and to a much lesser extent on the characteristic of the breach shape. Show more

Keywords: Dam failure, embankment dam, extension principle, fuzzy sets, outflow hydrograph, simplified analytical solver

DOI: 10.3233/IFS-141206

Citation: Journal of Intelligent & Fuzzy Systems, vol. 27, no. 5, pp. 2365-2378, 2014