http://www.hindawi.comThe latest articles from Hindawi Publishing Corporation© 2012, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/afs/2012/646248/In problems of graphs involving uncertainties, the fuzzy shortest path problem is one of the most studied topics, since it has a wide range of applications in different areas and therefore deserves special attention. In this paper, algorithms are proposed for the fuzzy shortest path problem, where the arc length of the network takes imprecise numbers, instead of real numbers, namely, level λ-triangular LR fuzzy numbers. Few indices defined in this paper help to identify the shortest path in fuzzy environment.S. Elizabeth and L. SujathaCopyright © 2012 S. Elizabeth and L. Sujatha. All rights reserved.http://www.hindawi.com/journals/afs/2011/216414/We introduce the classes of generalized difference bounded, convergent, and null sequences of fuzzy real numbers defined by an Orlicz function. Some properties of these sequence spaces like solidness, symmetricity, and convergence-free are studied. We obtain some inclusion relations involving these sequence spaces.Binod Chandra Tripathy and Stuti BorgohainCopyright © 2011 Binod Chandra Tripathy and Stuti Borgohain. All rights reserved.http://www.hindawi.com/journals/afs/2011/695690/The measures operation is an important component of borehole operation, and the operation effects directly affect the increase of oil and gas production. In perspective of the present reality of borehole operation company, the authors analyze the commonly used type of measures on the oil field, summarize six indicators to evaluate the measures operation effect, and give the quantitative calculation method for six evaluation indicators. Through the experts grading method, we can obtain all the weights of indicators and then establish the fuzzy comprehensive evaluation model of operation effect of measures. The evaluation model can be used to evaluate the operation effect of single well, oil block, or the branch company. Based on the actual data of measures operation of a branch company, using the fuzzy comprehensive evaluation approach to evaluate each block in the branch company, this paper obtained the same conclusion as the qualitative analysis.Zhi-Bin Liu, Wei Qing, and Xin-Hai KongCopyright © 2011 Zhi-Bin Liu et al. All rights reserved.http://www.hindawi.com/journals/afs/2011/986748/We prove two unique common coupled fixed-point theorems for self maps in symmetric G-fuzzy metric spaces.K. P. R. Rao, I. Altun, and S. Hima BinduCopyright © 2011 K. P. R. Rao et al. All rights reserved.http://www.hindawi.com/journals/afs/2011/879049/In this study the basic engineering principles, goals, and constraints are all combined with fuzzy methodology and applied to optimally design sandwich panel circular plate roofs for large vessels loaded statically and dynamically. These panels are made up of two stiff, strong veneer skins separated by vertical and peripheral stiffener plates. Advantages are high strength, lightweight, and sustainability. In the present approach, first the goals and constraints of the end user are identified and expressed as decision variables which are formulated using the engineering variables for materials, geometry, and function. Then same consistent fuzzy satisfaction functions are formed over the desired ranges to suit the customer's desires. The risk of extreme dynamic loadings exciting resonance is studied by natural frequency and mode analysis by FEM and analytical models. The results show the most critical locations and give guidelines for innovative remedies of the concept before detailed FEM analyses to finalize the design.Heikki Martikka and Erkki TaitokariCopyright © 2011 Heikki Martikka and Erkki Taitokari. All rights reserved.http://www.hindawi.com/journals/afs/2011/791695/We investigate a fuzzy version of stability for the functional equation f(x+y+z)+f(x−y)+f(x−z)−f(x−y−z)−f(x+y)−f(x+z)=0 in the sense of M. Mirmostafaee and M. S. Moslehian.Sun Sook Jin and Yang-Hi LeeCopyright © 2011 Sun Sook Jin and Yang-Hi Lee. All rights reserved.http://www.hindawi.com/journals/afs/2011/812040/We introduce the concepts of fuzzy Petri nets and marked fuzzy Petri nets along with their appropriate morphisms, which leads to two categories of such Petri nets. Some aspects of the internal structures of these categories are then explored, for example, their reflectiveness/coreflectiveness and symmetrical monoidal closed structure.Arun K. Srivastava and S. P. TiwariCopyright © 2011 Arun K. Srivastava and S. P. Tiwari. All rights reserved.http://www.hindawi.com/journals/afs/2011/831261/Functional link-based neural network models were applied to predict opencast mining machineries noise. The paper analyzes the prediction capabilities of functional link neural network based noise prediction models vis-à-vis existing statistical models. In order to find the actual noise status in opencast mines, some of the popular noise prediction models, for example, ISO-9613-2, CONCAWE, VDI, and ENM, have been applied in mining and allied industries to predict the machineries noise by considering various attenuation factors. Functional link artificial neural network (FLANN), polynomial perceptron network (PPN), and Legendre neural network (LeNN) were used to predict the machinery noise in opencast mines. The case study is based on data collected from an opencast coal mine of Orissa, India. From the present investigations, it could be concluded that the FLANN model give better noise prediction than the PPN and LeNN model.Santosh Kumar Nanda and Debi Prasad TripathyCopyright © 2011 Santosh Kumar Nanda and Debi Prasad Tripathy. All rights reserved.http://www.hindawi.com/journals/afs/2011/943161/Several authors have proposed different methods to find the solution of fully fuzzy linear systems (FFLSs) that is, fuzzy linear system with fuzzy coefficients involving fuzzy variables. But all the existing methods are based on the assumption that all the fuzzy coefficients and the fuzzy variables are nonnegative fuzzy numbers. In this paper a new method is proposed to solve an FFLS with arbitrary coefficients and arbitrary solution vector, that is, there is no restriction on the elements that have been used in the FFLS. The primary objective of this paper is thus to introduce the concept and a computational method for solving FFLS with no non negative constraint on the parameters. The method incorporates the principles of linear programming in solving an FFLS with arbitrary coefficients and is not only easier to understand but also widens the scope of fuzzy linear equations in scientific applications. To show the advantages of the proposed method over existing methods we solve three FFLSs.Amit Kumar, Neetu, and Abhinav BansalCopyright © 2011 Amit Kumar et al. All rights reserved.http://www.hindawi.com/journals/afs/2011/178308/Ranking fuzzy numbers are an important aspect of decision making in a fuzzy environment. Since their inception in 1965, many authors have proposed different methods for ranking fuzzy numbers. However, there is no method which gives a satisfactory result to all situations. Most of the methods proposed so far are nondiscriminating and counterintuitive. This paper proposes a new method for ranking fuzzy numbers based on the Circumcenter of Centroids and uses an index of optimism to reflect the decision maker's optimistic attitude and also an index of modality that represents the neutrality of the decision maker. This method ranks various types of fuzzy numbers which include normal, generalized trapezoidal, and triangular fuzzy numbers along with crisp numbers with the particularity that crisp numbers are to be considered particular cases of fuzzy numbers.P. Phani Bushan Rao and N. Ravi ShankarCopyright © 2011 P. Phani Bushan Rao and N. Ravi Shankar. All rights reserved.http://www.hindawi.com/journals/afs/2011/768028/A new class of generalized fuzzy open sets in fuzzy topological space, called fuzzy sp-open sets, are introduced, and their properties are studied and the relationship between this new concept and other weaker forms of fuzzy open sets we discussed. Moreover, we introduce the fuzzy sp-continuous (resp., fuzzy sp-open) mapping and other stronger forms of sp-continuous (resp., fuzzy sp-open) mapping and establish their various characteristic properties. Finally, we study the relationships between all these mappings and other weaker forms of fuzzy continuous mapping and introduce fuzzy sp-connected. Counter examples are given to show the noncoincidence of these sets and mappings.Hakeem A. OthmanCopyright © 2011 Hakeem A. Othman. All rights reserved.http://www.hindawi.com/journals/afs/2011/941982/We use the concepts of the quasicoincident relation to introduce and investigate some lower separation axioms such as αT0, αT1, αT1/2, and αT2 as well as the regularity axioms αR0 and αR1. Further we study some of their properties and the relations among them in the general framework of fuzzy topological spaces.Amin Saif and Adem KılıçmanCopyright © 2011 Amin Saif and Adem Kılıçman. All rights reserved.http://www.hindawi.com/journals/afs/2011/791687/In this study, the basic engineering principles, goals, and constraints are all combined to fuzzy methodology and applied to design of optimally pressurised containers emphasising the ecological and durability merits of various materials. The present fuzzy heuristics approach is derivable from generalisation of conventional analytical optimisation method into fuzzy multitechnical tasks. In the present approach, first the goals and constraints of the end-user are identified. Then decision variables are expressed as functions of the design variables. Their desirable ranges and biases are defined using the same fuzzy satisfaction function form. The optimal result has highest total satisfaction. These are then checked and fine-tuned by finite element method FEM. The optimal solution is the ecoplastic vessel, and aluminium was close. The method reveals that optimum depends strongly on the preset goals and values of the producer, society, and end-user.Heikki Martikka and Erkki TaitokariCopyright © 2011 Heikki Martikka and Erkki Taitokari. All rights reserved.http://www.hindawi.com/journals/afs/2010/781672/The concept of intuitionistic fuzzy ideal of an intuitionistic fuzzy lattice is introduced, and its certain characterizations are provided. We defined the quotient (or residual) of ideals of an intuitionistic fuzzy sublattice and studied their properties.K. V. Thomas and Latha S. NairCopyright © 2010 K. V. Thomas and Latha S. Nair. All rights reserved.http://www.hindawi.com/journals/afs/2010/258947/We use a translational invariant fuzzy subset p of a ring R to define two new types of commutative rings namely, p-presimplifiable and p-associate rings. We present some results of these rings. The interest of these results is that most of them are mirrors of corresponding results of presimplifiable and associate rings in classical ring theory.Manal GhanemCopyright © 2010 Manal Ghanem. All rights reserved.http://www.hindawi.com/journals/afs/2010/763270/Instead of using standard analytical techniques, like Buckley and Qu method, which are not suitable for solving a system of fuzzy nonlinear equations where the coefficient is fuzzy number, Broyden's method is proposed for solving fuzzy nonlinear equations. In this paper, an eight-step algorithm is used to solve fuzzy nonlinear equations. Two numerical examples are given to illustrate the proposed method.Amirah Ramli, Mohd Lazim Abdullah, and Mustafa MamatCopyright © 2010 Amirah Ramli et al. All rights reserved.http://www.hindawi.com/journals/afs/2010/879453/We focus on the equity mutual funds offered by three Malaysian banks, namely Public Bank Berhad, CIMB, and Malayan Banking Berhad. The equity mutual funds or equity trust is grouped into four clusters based on their characteristics and categorized as inferior, stable, good performing, and aggressive funds based on their return rates, variance and treynor index. Based on the cluster analysis, the return rates and variance of clusters are represented as triangular fuzzy numbers in order to reflect the uncertainty of financial market. To find the optimal asset allocation in each cluster we develop a hybrid model of optimization and fuzzy based on return rates, variance. This was done by maximizing the fuzzy return for a tolerable fuzzy risk and minimizing the fuzzy risk for a desirable fuzzy return separately at different confidence levels.Adem Kılıçman and Jaisree SivalingamCopyright © 2010 Adem Kılıçman and Jaisree Sivalingam. All rights reserved.http://www.hindawi.com/journals/afs/2009/172917/In 1992, Ramadan introduced the concept of a smooth topological space and relativeness between smooth topological space and fuzzy topological space in Chang's (1968) view points. In this paper we give a new definition of smooth topological space. This definition can be considered as a generalization of the smooth topological space which was given by Ramadan. Some general properties such as relative smooth continuity and relative smooth compactness are studied.B. GhazanfariCopyright © 2009 B. Ghazanfari. All rights reserved.http://www.hindawi.com/journals/afs/2009/450259/This paper proposes a fuzzy modelling approach oriented to the design of a fuzzy controller for regulating the fresh airflow of a real diesel engine. This strategy has been suggested for enhancing the regulator design that could represent an alternative to the standard embedded BOSCH controller, already implemented in the Engine Control Unit (ECU), without any change to the engine instrumentation. The air system controller project requires the knowledge of a dynamic model of the diesel engine, which is achieved by means of the suggested fuzzy modelling and identification scheme. On the other hand, the proposed fuzzy PI controller structure is straightforward and easy to implement with respect to different strategies proposed in literature. The results obtained with the designed fuzzy controller are compared to those of the traditional embedded BOSCH controller.S. Simani and M. BonfèCopyright © 2009 S. Simani and M. Bonfè. All rights reserved.http://www.hindawi.com/journals/afs/2009/407890/We define the concept of a mapping on classes of fuzzy soft sets and study the properties of fuzzy soft images and fuzzy soft inverse images of fuzzy soft sets, and support them with examples and counterexamples.Athar Kharal and B. AhmadCopyright © 2009 Athar Kharal and B. Ahmad. All rights reserved.http://www.hindawi.com/journals/afs/2009/586507/We further contribute to the properties of fuzzy soft sets as defined and studied in the work of Maji et al. ( 2001), Roy and Maji (2007), and Yang et al. (2007) and support them with examples and counterexamples. We improve Proposition 3.3 by Maji et al., (2001). Finally we define arbitrary fuzzy soft union and fuzzy soft intersection and prove DeMorgan Inclusions and DeMorgan Laws in Fuzzy Soft Set Theory.B. Ahmad and Athar KharalCopyright © 2009 B. Ahmad and Athar Kharal. All rights reserved.http://www.hindawi.com/journals/afs/2009/148193/This paper investigates the dynamical systems in the context of topological semigroup actions on intuitionistic fuzzy metric spaces. We give some concepts such as topological transitivity, point transitivity, and densely point transitivity for such dynamical systems. Particularly, we consider the implications of nonsensitivity and its relation to dynamical properties such as transitivity and equicontinuity.Yaoyao Lan and Qingguo LiCopyright © 2009 Yaoyao Lan and Qingguo Li. All rights reserved.http://www.hindawi.com/journals/afs/2009/303042/Several properties of fuzzy semiclosure and fuzzy semi-interior of fuzzy sets defined by Yalvac (1988), have been established and supported by counterexamples. We also study the characterizations and properties of fuzzy semi-open and fuzzy semi-closed sets. Moreover, we define fuzzy s-open and fuzzy s-closed mappings and give some interesting characterizations.B. Ahmad and Athar KharalCopyright © 2009 B. Ahmad and Athar Kharal. All rights reserved.http://www.hindawi.com/journals/afs/2009/241809/This paper presents a new method of online estimation of the stator and rotor resistance of the induction motor in the indirect vector-controlled drive, with artificial neural networks. The back propagation algorithm is used for training of the neural networks. The error between the rotor flux linkages based on a neural network model and a voltage model is back propagated to adjust the weights of the neural network model for the rotor resistance estimation. For the stator resistance estimation, the error between the measured stator current and the estimated stator current using neural network is back propagated to adjust the weights of the neural network. The performance of the stator and rotor resistance estimators and torque and flux responses of the drive, together with these estimators, is investigated with the help of simulations for variations in the stator and rotor resistance from their nominal values. Both types of resistance are estimated experimentally, using the proposed neural network in a vector-controlled induction motor drive. Data on tracking performances of these estimators are presented. With this approach, the rotor resistance estimation was found to be insensitive to the stator resistance variations both in simulation and experiment.Baburaj Karanayil, Muhammed Fazlur Rahman, and Colin GranthamCopyright © 2009 Baburaj Karanayil et al. All rights reserved.http://www.hindawi.com/journals/afs/2008/963710/Extraction of maximum wind power of variable speed wind turbines in hybrid wind-diesel-storage system (HWDSS) is considered due to economical purposes. The proposed control algorithm utilizes extended fuzzy-linear matrix equalities (FLMEs) systems design of stabilizing fuzzy controllers for nonlinear systems described by Takagi-Sugeno (TS) fuzzy models. The algorithm maximizes the power coefficient for a fixed pitch. Moreover, it reduces the voltage ripple and stabilizes the system over a wide range of wind speed variations. The control scheme is tested for different profiles of wind speed pattern and provides satisfactory results.Elkhatib Kamal, Magdy Koutb, Abdul Azim Sobaih, and Sahar KaddahCopyright © 2008 Elkhatib Kamal et al. All rights reserved.http://www.hindawi.com/journals/afs/2008/295649/The aim of this paper is the generalization of the notion of fuzzy vector spaces to fuzzy hypervector spaces. In this regard, by considering the notion of fuzzy hypervector spaces, we characterized a fuzzy hypervector space based on its level sub-hyperspace. The algebraic nature of fuzzy hypervector space under transformations is studied. Certain conditions are obtained under which a given fuzzy hypervector space can or cannot be realized as a union of two fuzzy hypervector spaces such that none is contained in the other. The construction of a fuzzy hypervector space generated by a given fuzzy subset of a hypervector space is given. The set of all fuzzy cosets of a fuzzy hypervector space is shown to be a hypervector space. Finally, a fuzzy quotient hypervector space is defined and an analogue of a consequence of the “fundamental theorem of homomorphisms” is obtained.R. Ameri and O. R. DehghanCopyright © 2008 R. Ameri and O. R. Dehghan. All rights reserved.http://www.hindawi.com/journals/afs/2008/920615/A novel digital image stabilization technique is proposed in this paper. It is based on a fuzzy Kalman compensation of the global motion vector (GMV), which is estimated in the log-polar plane. The GMV is extracted using four local motion vectors (LMVs) computed on respective subimages in the logpolar plane. The fuzzy Kalman system consists of a fuzzy system with the Kalman filter's discrete time-invariant definition. Due to this inherited recursiveness, the output results into smoothed image sequences. The proposed stabilization system aims to compensate any oscillations of the frame absolute positions, based on the motion estimation in the log-polar domain, filtered by the fuzzy Kalman system, and thus the advantages of both the fuzzy Kalman system and the log-polar transformation are exploited. The described technique produces optimal results in terms of the output quality and the level of compensation.Nikolaos Kyriakoulis and Antonios GasteratosCopyright © 2008 Nikolaos Kyriakoulis and Antonios Gasteratos. All rights reserved.http://www.hindawi.com/journals/afs/2008/586893/We present several properties of fuzzy boundary and fuzzy semiboundary which have been supported by examples. Properties of fuzzy semi-interior, fuzzy semiclosure, fuzzy boundary, and fuzzy semiboundary have been obtained in product-related spaces. We give necessary conditions for fuzzy continuous (resp., fuzzy semicontinuous, fuzzy irresolute) functions. Moreover, fuzzy continuous (resp., fuzzy semicontinuous, fuzzy irresolute) functions have been characterized via fuzzy-derived (resp., fuzzy-semiderived) sets.M. Athar and B. AhmadCopyright © 2008 M. Athar and B. Ahmad. All rights reserved.http://www.hindawi.com/journals/afs/2008/691808/This paper presents the real-time implementation of a fuzzy coordinated classical PI control scheme for controlling the pressure in a pilot pressure tank system. The fuzzy system has been designed to track the variation parameters in a feedback loop and tune the classical controller to achieve a better control action for load disturbances and set point changes. The error and process inputs are chosen as the inputs of fuzzy system to tune the conventional PI controller according to the process condition. This online conventional controller tuning technique will reduce the human involvement in controller tuning and increase the operating range of the conventional controller. The proposed control algorithm is experimentally implemented for the real-time pressure control of a pilot air tank system and validated using a high-speed 32-bit ARM7 embedded microcontroller board (ATMEL AT91M55800A). To demonstrate the performance of the fuzzy coordinated PI control scheme, results are compared with a classical PI and PI-type fuzzy control method. It is observed that the proposed controller structure is able to quickly track the parameter variation and perform better in load disturbances and also for set point changes.N. Kanagaraj, P. Sivashanmugam, and S. ParamasivamCopyright © 2008 N. Kanagaraj et al. All rights reserved.http://www.hindawi.com/journals/afs/2008/421525/We provide a way to combine matrix Lyapunov systems with fuzzy rules to form a new fuzzy system called fuzzy dynamical matrix Lyapunov system, which can be regarded as a new approach to intelligent control. First, we study the controllability property of the fuzzy dynamical matrix Lyapunov system and provide a sufficient condition for its controllability with the use of fuzzy rule base. The significance of our result is that given a deterministic system and a fuzzy state with rule base, we can determine the rule base for the control. Further, we discuss the concept of observability and give a sufficient condition for the system to be observable. The advantage of our result is that we can determine the rule base for the initial value without solving the system.M. S. N. Murty and G. Suresh KumarCopyright © 2008 M. S. N. Murty and G. Suresh Kumar. All rights reserved.