http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2013 , Hindawi Publishing Corporation . All rights reserved. Wed, 19 Jun 2013 09:45:09 +0000 http://www.hindawi.com/journals/afs/2013/504728/ Sendren Sheng-Dong Xu, Hao Ying, Pablo Carbonell, Ching-Hung Lee, and Wei-Sheng Wu Copyright © 2013 Sendren Sheng-Dong Xu et al. All rights reserved. Tue, 18 Jun 2013 15:59:19 +0000 http://www.hindawi.com/journals/afs/2013/421621/ Dissolved gas analysis (DGA) of transformer oil has been one of the most reliable techniques to detect the incipient faults. Many conventional DGA methods have been developed to interpret DGA results obtained from gas chromatography. Although these methods are widely used in the world, they sometimes fail to diagnose, especially when DGA results fall outside conventional methods codes or when more than one fault exist in the transformer. To overcome these limitations, the fuzzy inference system (FIS) is proposed. Two hundred different cases are used to test the accuracy of various DGA methods in interpreting the transformer condition. Nitin K. Dhote and Jagdish B. Helonde Copyright © 2013 Nitin K. Dhote and Jagdish B. Helonde. All rights reserved. Mon, 17 Jun 2013 15:16:45 +0000 http://www.hindawi.com/journals/afs/2013/806749/ In today’s increasingly competitive market, consumers usually have to face a huge number of products with different designs but having the same use. Therefore, an important problem for manufacturers is to attract consumers by special designs of the products. This paper aims at the improvement of a consumer-oriented approach in recommending products, and proposing a recommendation system for Japanese traditional crafts based on target-oriented fuzzy method and ontological engineering. Specifically, a target-oriented fuzzy method is used for measuring the fitness of a selected attribute to a certain object. Two aggregation models for dealing with a multiattribute evaluation and ranking are introduced; four ranking methods are also examined for getting a recommendation list. To test the aggregation models and the ranking methods, a recommendation system was developed and a comparison test was conducted. Jing-Zhong Jin, Yoshiteru Nakamori, and Andrzej P. Wierzbicki Copyright © 2013 Jing-Zhong Jin et al. All rights reserved. Tue, 04 Jun 2013 14:57:55 +0000 http://www.hindawi.com/journals/afs/2013/760704/ We apply the concept of Fuzzy Transform (for short, F-transform) for improving the results of the image matching based on the Greatest Eigen Fuzzy Set (for short, GEFS) with respect to max-min composition and the Smallest Eigen Fuzzy Set (for short, SEFS) with respect to min-max composition already studied in the literature. The direct F-transform of an image can be compared with the direct F-transform of a sample image to be matched and we use suitable indexes to measure the grade of similarity between the two images. We make our experiments on the image dataset extracted from the well-known Prima Project View Sphere Database, comparing the results obtained with this method with that one based on the GEFS and SEFS. Other experiments are performed on frames of videos extracted from the Ohio State University dataset. Ferdinando Di Martino and Salvatore Sessa Copyright © 2013 Ferdinando Di Martino and Salvatore Sessa. All rights reserved. Wed, 29 May 2013 19:24:33 +0000 http://www.hindawi.com/journals/afs/2013/197435/ Fuzzy set theory, rough set theory, and soft set theory are three effective mathematical tools for dealing with uncertainties and have many wide applications both in theory and practise. Meng et al. (2011) introduced the notion of soft fuzzy rough sets by combining fuzzy sets, rough sets, and soft sets all together. The aim of this paper is to study the parameter reduction of fuzzy soft sets based on soft fuzzy rough approximation operators. We propose some concepts and conditions for two fuzzy soft sets to generate the same lower soft fuzzy rough approximation operators and the same upper soft fuzzy rough approximation operators. The concept of reduct of a fuzzy soft set is introduced and the procedure to find a reduct for a fuzzy soft set is given. Furthermore, the concept of exclusion of a fuzzy soft set is introduced and the procedure to find an exclusion for a fuzzy soft set is given. Zhiming Zhang Copyright © 2013 Zhiming Zhang. All rights reserved. Sun, 12 May 2013 11:54:53 +0000 http://www.hindawi.com/journals/afs/2013/496158/ The quality characteristics in the wafer fabrication process are diverse, variable, and fuzzy in nature. How to effectively deal with multiresponse quality problems in the wafer fabrication process is a challenging task. In this study, the fuzzy technique for order preference by similarity to an ideal solution (TOPSIS), one of the fuzzy multiattribute decision-analysis (MADA) methods, is proposed to investigate the fuzzy multiresponse quality problem in integrated-circuit (IC) wafer fabrication process. The fuzzy TOPSIS is one of the effective fuzzy MADA methods for dealing with decision-making problems under uncertain environments. First, a fuzzy TOPSIS methodology is developed by considering the ambiguity between quality characteristics. Then, a detailed procedure for the developed fuzzy TOPSIS approach is presented to show how the fuzzy wafer fabrication quality problems can be solved. Real-world data is collected from an IC semiconductor company and the developed fuzzy TOPSIS approach is applied to find an optimal combination of parameters. Results of this study show that the developed approach provides a satisfactory solution to the wafer fabrication multiresponse problem. This developed approach can be also applied to other industries for investigating multiple quality characteristics problems. Chiun-Ming Liu, Mei-Yu Ji, and Wen-Chieh Chuang Copyright © 2013 Chiun-Ming Liu et al. All rights reserved. Tue, 30 Apr 2013 11:28:04 +0000 http://www.hindawi.com/journals/afs/2013/613604/ We define approximate fixed point and fuzzy diameter in fuzzy norm spaces. We prove theorems for various types of well-known generalized contractions on fuzzy norm spaces with the use of two general lemmas that are given regarding approximate fixed points of operators on fuzzy norm spaces. S. A. M. Mohsenalhosseini and H. Mazaheri Copyright © 2013 S. A. M. Mohsenalhosseini and H. Mazaheri. All rights reserved. Sun, 21 Apr 2013 10:57:15 +0000 http://www.hindawi.com/journals/afs/2013/410956/ Nor Hashimah Sulaiman and Daud Mohamad Copyright © 2013 Nor Hashimah Sulaiman and Daud Mohamad. All rights reserved. Thu, 14 Mar 2013 14:36:36 +0000 http://www.hindawi.com/journals/afs/2013/874393/ A method of fault diagnosis in dynamic systems based on a fuzzy approach is proposed. The new method possesses two basic specific features which distinguish it from the other known fuzzy methods based on the application of fuzzy logic and a bank of state observers. First, this method uses a bank of interacting observers instead of traditional independent observers. The second specific feature of the proposed method is the assumption that there is no strict boundary between the serviceable and disabled technical states of the system, which makes it possible to specify a decision making rule for fault diagnosis. N. V. Kolesov Copyright © 2013 N. V. Kolesov. All rights reserved. Thu, 14 Mar 2013 09:43:10 +0000 http://www.hindawi.com/journals/afs/2013/792059/ A sensor resource management system that employs fuzzy logic to provide the utility functions to a game theoretic approach is developed. The application looks at a virtual fence problem where several unattended ground sensors are placed in remote locations to act as virtual sentries. The goal of the approach is to maximize the battery life while tracking targets of interest. This research also considers the incorporation of uncertainty into the fuzzy membership functions. Both type-2 fuzzy logic and the use of conditional fuzzy membership function are employed. The type-2 fuzzy logic is employed in the case of acoustical sensor tracking accuracy degradation, while the condition-based membership functions are used to adapt to different conditions, such as environmental conditions and sensor performance degradation, over time. The resource management process uses fuzzy logic to determine which of the sensor systems on a sensor pod is used to provide initial classification of the target and which sensor or sensors are to be used in tracking and better classifying the target if it is determined to be of value to the mission. The three different approaches are compared to determine when the best times for the more complex approaches are warranted. Stephen C. Stubberud and Kathleen A. Kramer Copyright © 2013 Stephen C. Stubberud and Kathleen A. Kramer. All rights reserved. Sun, 03 Mar 2013 13:32:55 +0000 http://www.hindawi.com/journals/afs/2013/319542/ In 1999, Molodtsov introduced the concept of soft set theory as a general mathematical tool for dealing with uncertainty and vagueness. In this paper, we apply the concept of soft sets to K-algebras and investigate some properties of Abelian soft K-algebras. We also introduce the concept of soft intersection K-algebras and investigate some of their properties. N. O. Alshehri, M. Akram, and R. S. Al-ghamdi Copyright © 2013 N. O. Alshehri et al. All rights reserved. Thu, 28 Feb 2013 16:59:46 +0000 http://www.hindawi.com/journals/afs/2013/601468/ In the context of sustainable transportation systems, previous studies have either focused only on the transportation system or have not used a methodology that enables the treatment of incomplete, vague, and qualitative information associated with the available data. This study proposes a system of systems (SOS) and a fuzzy logic modeling approach. The SOS includes the Transportation, Activity, and Environment systems. The fuzzy logic modeling approach enables the treatment of the vagueness associated with some of the relevant data. Performance Indices (PIs) are computed for each system using a number of performance measures. The PIs illustrate the aggregated performance of each system as well as the interactions among them. The proposed methodology also enables the estimation of a Composite Sustainability Index to summarize the aggregated performance of the overall SOS. Existing data was used to analyze sustainability in the entire United States. The results showed that the Transportation and Activity systems follow a positive trend, with similar periods of growth and contractions; in contrast, the environmental system follows a reverse pattern. The results are intuitive and are associated with a series of historic events, such as depressions in the economy as well as policy changes and regulations. Alexander Paz, Pankaj Maheshwari, Pushkin Kachroo, and Sajjad Ahmad Copyright © 2013 Alexander Paz et al. All rights reserved. Sun, 24 Feb 2013 10:41:57 +0000 http://www.hindawi.com/journals/afs/2013/232198/ A heterogeneous wireless network is characterized by the presence of different wireless access technologies that coexist in an overlay fashion. These wireless access technologies usually differ in terms of their operating parameters. On the other hand, Mobile Stations (MSs) in a heterogeneous wireless network are equipped with multiple interfaces to access different types of services from these wireless access technologies. The ultimate goal of these heterogeneous wireless networks is to provide global connectivity with efficient ubiquitous computing to these MSs based on the Always Best Connected (ABC) principle. This is where the need for intelligent and efficient Vertical Handoffs (VHOs) between wireless technologies in a heterogeneous environment becomes apparent. This paper presents the design and implementation of a fuzzy multicriteria based Vertical Handoff Necessity Estimation (VHONE) scheme that determines the proper time for VHO, while considering the continuity and quality of the currently utilized service, and the end-users' satisfaction. Faisal Kaleem, Abolfazl Mehbodniya, Kang K. Yen, and Fumiyuki Adachi Copyright © 2013 Faisal Kaleem et al. All rights reserved. Thu, 21 Feb 2013 14:48:38 +0000 http://www.hindawi.com/journals/afs/2013/164853/ This paper discusses the multicrack detection of structure using fuzzy Gaussian technique. The vibration parameters derived from the numerical methods of the cracked cantilever beam are used to set several fuzzy rules for designing the fuzzy controller used to predict the crack location and depth. Relative crack locations and relative crack depths are the output parameters from the fuzzy inference system. The method proposed in the current analysis is used to evaluate the dynamic response of cracked cantilever beam. The results of the proposed method are in good agreement with the results obtained from the developed experimental setup. Amiya Kumar Dash Copyright © 2013 Amiya Kumar Dash. All rights reserved. Thu, 21 Feb 2013 11:50:08 +0000 http://www.hindawi.com/journals/afs/2013/342805/ Our aim in the present paper is to introduce and study new types of fuzzy retractions of fuzzy open flat Robertson-Walker model. New types of the fuzzy deformation retracts of model are obtained. The relations between the fuzzy foldings and the fuzzy deformation retracts of model are deduced. Types of fuzzy minimal retractions are also presented. New types of homotopy maps are deduced. New types of conditional fuzzy folding are presented. Some commutative diagrams are obtained. A. E. El-Ahmady and A. S. Al-Luhaybi Copyright © 2013 A. E. El-Ahmady and A. S. Al-Luhaybi. All rights reserved. Sun, 10 Feb 2013 14:17:21 +0000 http://www.hindawi.com/journals/afs/2013/158969/ This paper presents two new algorithms that speed up the centroid computation of an interval type-2 fuzzy set. The algorithms include precomputation of the main operations and initialization based on the concept of uncertainty bounds. Simulations over different kinds of footprints of uncertainty reveal that the new algorithms achieve computation time reductions with respect to the Enhanced-Karnik algorithm, ranging from 40 to 70%. The results suggest that the initialization used in the new algorithms effectively reduces the number of iterations to compute the extreme points of the interval centroid while precomputation reduces the computational cost of each iteration. Carlos E. Celemin and Miguel A. Melgarejo Copyright © 2013 Carlos E. Celemin and Miguel A. Melgarejo. All rights reserved. Mon, 28 Jan 2013 11:49:03 +0000 http://www.hindawi.com/journals/afs/2013/343174/ The real-time nondestructive testing (NDT) for crack detection and impact source identification (CDISI) has attracted the researchers from diverse areas. This is apparent from the current work in the literature. CDISI has usually been performed by visual assessment of waveforms generated by a standard data acquisition system. In this paper we suggest an automation of CDISI for metal armor plates using a soft computing approach by developing a fuzzy inference system to effectively deal with this problem. It is also advantageous to develop a chip that can contribute towards real time CDISI. The objective of this paper is to report on efforts to develop an automated CDISI procedure and to formulate a technique such that the proposed method can be easily implemented on a chip. The CDISI fuzzy inference system is developed using MATLAB’s fuzzy logic toolbox. A VLSI circuit for CDISI is developed on basis of fuzzy logic model using Verilog, a hardware description language (HDL). The Xilinx ISE WebPACK9.1i is used for design, synthesis, implementation, and verification. The CDISI field-programmable gate array (FPGA) implementation is done using Xilinx’s Spartan 3 FPGA. SynaptiCAD’s Verilog Simulators—VeriLogger PRO and ModelSim—are used as the software simulation and debug environment. Arati M. Dixit and Harpreet Singh Copyright © 2013 Arati M. Dixit and Harpreet Singh. All rights reserved. Tue, 22 Jan 2013 16:13:36 +0000 http://www.hindawi.com/journals/afs/2013/294971/ The paper presents new conditions suitable in design of a stabilizing output controller for a class of continuous-time nonlinear systems, represented by Takagi-Sugeno models. Taking into account the affine properties of the TS model structure and applying the fuzzy control scheme relating to the parallel distributed output compensators, the sufficient design conditions are outlined in terms of linear matrix inequalities. The proposed procedure decouples the Lyapunov matrix and the system parameter matrices in the LMIs and guarantees global stability of the system. Simulation result illustrates the design procedure and demonstrates the performances of the proposed design method. Dušan Krokavec and Anna Filasová Copyright © 2013 Dušan Krokavec and Anna Filasová. All rights reserved. Mon, 21 Jan 2013 08:05:16 +0000 http://www.hindawi.com/journals/afs/2013/680486/ We introduce a novel concept of multiaspect soft set which is an extension of the ordinary soft set by Molodtsov. Some basic concepts, operations, and properties of the multiaspect soft sets are studied. We also define a mapping on multiaspect soft classes and investigate several properties related to the images and preimages of multiaspect soft sets. Nor Hashimah Sulaiman and Daud Mohamad Copyright © 2013 Nor Hashimah Sulaiman and Daud Mohamad. All rights reserved. Wed, 26 Dec 2012 10:51:41 +0000 http://www.hindawi.com/journals/afs/2012/604396/ In this paper we have studied separation axioms , in an intuitionistic fuzzy topological space introduced by Coker. We also show the existence of functors and and observe that is left adjoint to . Amit Kumar Singh and Rekha Srivastava Copyright © 2012 Amit Kumar Singh and Rekha Srivastava. All rights reserved. Sun, 23 Dec 2012 07:51:33 +0000 http://www.hindawi.com/journals/afs/2012/316187/ Oscar Montiel Ross, Roberto Sepúlveda Cruz, Oscar Castillo, and Alper Basturk Copyright © 2012 Oscar Montiel Ross et al. All rights reserved. Tue, 18 Dec 2012 15:41:00 +0000 http://www.hindawi.com/journals/afs/2012/823052/ A fuzzy rule-based expert system is developed for evaluating intellectual capital. A fuzzy linguistic approach assists managers to understand and evaluate the level of each intellectual capital item. The proposed fuzzy rule-based expert system applies fuzzy linguistic variables to express the level of qualitative evaluation and criteria of experts. Feasibility of the proposed model is demonstrated by the result of intellectual capital performance evaluation for a sample company. Mohammad Hossein Fazel Zarandi, Neda Mohammadhasan, and Susan Bastani Copyright © 2012 Mohammad Hossein Fazel Zarandi et al. All rights reserved. Mon, 17 Dec 2012 09:28:35 +0000 http://www.hindawi.com/journals/afs/2012/640951/ Salvatore Sessa, Ferdinando Di Martino, and Irina G. Perfilieva Copyright © 2012 Salvatore Sessa et al. All rights reserved. Tue, 11 Dec 2012 15:24:52 +0000 http://www.hindawi.com/journals/afs/2012/927878/ Nowadays network control systems present a common approximation when connectivity is the issue to be solved based on time delays coupling from external factors. However, this approach tends to be complex in terms of time delays. Therefore, it is necessary to study the behavior of the delays as well as the integration into differential equations of these bounded delays. The related time delays needs to be known a priory but from a dynamic real-time behavior. To do so, the use of priority dynamic Priority exchange scheduling is performed. The objective of this paper is to show a way to tackle multiple time delays that are bounded and the dynamic response from real-time scheduling approximation. The related control law is designed considering fuzzy logic approximation for nonlinear time delays coupling, where the main advantage is the integration of this behavior through extended state space representation keeping certain linear and bounded behavior and leading to a stable situation during events presentation by guaranteeing stability through Lyapunov. H. Benítez-Pérez, A. Benítez-Pérez, J. Ortega-Arjona, and O. Esquivel-Flores Copyright © 2012 H. Benítez-Pérez et al. All rights reserved. Tue, 04 Dec 2012 13:40:29 +0000 http://www.hindawi.com/journals/afs/2012/504368/ In general, the modelling of wind turbines is a challenging task, since they are complex dynamic systems, whose aerodynamics are nonlinear and unsteady. Accurate models should contain many degrees of freedom, and their control algorithm design must account for these complexities. However, these algorithms must capture the most important turbine dynamics without being too complex and unwieldy, mainly when they have to be implemented in real-time applications. The first contribution of this work consists of providing an application example of the design and testing through simulations, of a data-driven fuzzy wind turbine control. In particular, the strategy is based on fuzzy modelling and identification approaches to model-based control design. Fuzzy modelling and identification can represent an alternative for developing experimental models of complex systems, directly derived directly from measured input-output data without detailed system assumptions. Regarding the controller design, this paper suggests again a fuzzy control approach for the adjustment of both the wind turbine blade pitch angle and the generator torque. The effectiveness of the proposed strategies is assessed on the data sequences acquired from the considered wind turbine benchmark. Several experiments provide the evidence of the advantages of the proposed regulator with respect to different control methods. Silvio Simani Copyright © 2012 Silvio Simani. All rights reserved. Tue, 04 Dec 2012 10:07:37 +0000 http://www.hindawi.com/journals/afs/2012/687652/ This paper presents a novel fuzzy deterministic noncontroller type (FDNCT) system and an FDNCT inference algorithm (FIA). The FDNCT uses fuzzy inputs and produces a deterministic non-fuzzy output. The FDNCT is an extension and alternative for the existing fuzzy singleton inference algorithm. The research described in this paper applies FDNCT to build an architecture for an intelligent system to detect and to eliminate potential fires in the engine and battery compartments of a hybrid electric vehicle. The fuzzy inputs consist of sensor data from the engine and battery compartments, namely, temperature, moisture, and voltage and current of the battery. The system synthesizes the data and detects potential fires, takes actions for eliminating the hazard, and notifies the passengers about the potential fire using an audible alarm. This paper also presents the computer simulation results of the comparison between the FIA and singleton inference algorithms for detecting potential fires and determining the actions for eliminating them. Macam S. Dattathreya, Harpreet Singh, and Thomas Meitzler Copyright © 2012 Macam S. Dattathreya et al. All rights reserved. Mon, 03 Dec 2012 15:55:26 +0000 http://www.hindawi.com/journals/afs/2012/828593/ This study examines the problems of reduction of individual’s efficiency in his/her respective working places because of road traffic noise pollution in Agartala due to rapidly growing vehicular traffic. This paper deals with monitoring and modeling of the disturbances caused due to vehicular road traffic interrupted by traffic flow conditions on personal work performance. Total of two hundred seventy individuals from different road side Government Offices, Private Organizations and Commercial Business Centres on both sides of busy roads of the city were interviewed for attitudinal responses. Traffic volume count and noise indices data were collected simultaneously at six selected sites of the city. A relationship was developed between different traffic noise parameters and its harmful impact on work competency of individuals using MATLAB. Regression equations developed to predict the percentage of high annoyance among the individuals are fit based on noise parameters and parameters related to traffic movements. In addition, statistical analysis was also carried out between measured and predictive values of the percentage of highly annoyed group of individuals. The present model will draw the attention of the State Government and will help the policy maker to take the necessary steps to reduce this problem. Debasish Pal and Debasish Bhattacharya Copyright © 2012 Debasish Pal and Debasish Bhattacharya. All rights reserved. Mon, 26 Nov 2012 14:56:28 +0000 http://www.hindawi.com/journals/afs/2012/406204/ Modern military ranging, tracking, and classification systems are capable of generating large quantities of data. Conventional “brute-force” computational techniques, even with Moore’s law for processors, present a prohibitive computational challenge, and often, the system either fails to “lock onto” a target of interest within the available duty cycle, or the data stream is simply discarded because the system runs out of processing power or time. In searching for high-fidelity convergence, researchers have experimented with various reduction techniques, often using logic diagrams to make inferences from related signal data. Conventional Boolean and fuzzy logic systems generate a very large number of rules, which often are difficult to handle due to limitations in the processors. Published research has shown that reasonable approximations of the target are preferred over incomplete computations. This paper gives a figure of merit for comparing various logic analysis methods and presents results for a hypothetical target classification scenario. Novel multiquantization Boolean approaches also reduce the complexity of these multivariate analyses, making it possible to better use the available data to approximate target classification. This paper shows how such preprocessing can reasonably preserve result confidence and compares the results between Boolean, multi-quantization Boolean, and fuzzy techniques. Rahul Dixit and Harpreet Singh Copyright © 2012 Rahul Dixit and Harpreet Singh. All rights reserved. Thu, 22 Nov 2012 07:47:31 +0000 http://www.hindawi.com/journals/afs/2012/201248/ This paper describes a fuzzy system of stem implantation on total hip arthroplasty by an ultrasonic device. The system can perform automatic and accurate assessment in the surgery. In this system, we employ a single ultrasonic probe whose center frequency is 1,000 Hz. We detect the acoustic signals when knocking the inserted stem with a hammer. We then have a correlation between the degree of tightening and the attenuation time of acoustic signal. That is, the higher tightened degree implies shorter attenuation period. The support system selects the most suitable stem size by fuzzy inference with respect to the attenuation time and its difference time from correct stem to one larger size stem which dynamically adapts to each patient. As a result, we successfully determined the suitable stem in comparison to the results of the practical surgery. Naomi Yagi, Yutaka Hata, and Nao Shibanuma Copyright © 2012 Naomi Yagi et al. All rights reserved. Tue, 20 Nov 2012 16:12:59 +0000 http://www.hindawi.com/journals/afs/2012/801650/ Prime fuzzy ideals, prime fuzzy k-ideals, and prime fuzzy h-ideals are roped in one condition. It is shown that this way better fuzzification is achieved. Other major results of the paper are: every fuzzy ideal (resp., k-ideal, h-ideal) is contained in a prime fuzzy ideal (resp., k-ideal, h-ideal). Prime radicals and nil radicals of a fuzzy ideal are defined; their relationship is established. The nil radical of a fuzzy k-ideal (resp., an h-ideal) is proved to be a fuzzy k-ideal (resp., h-ideal). The correspondence theorems for different types of fuzzy ideals of hemirings are established. The concept of primary fuzzy ideal is introduced. Minimum imperative for proper fuzzification is suggested and it is shown that the fuzzifications introduced in this paper are proper fuzzifications. H. V. Kumbhojkar Copyright © 2012 H. V. Kumbhojkar. All rights reserved.