http://www.hindawi.comThe latest articles from Hindawi Publishing Corporation© 2012, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/mpe/2012/931802/We propose a novel true random number generator using mouse movement and a one-dimensional chaotic map. We utilize the x-coordinate of the mouse movement to be the length of an iteration segment of our TRNs and the y-coordinate to be the initial value of this iteration segment. And, when it iterates, we perturb the parameter with the real value produced by the TRNG itself. And we find that the TRNG we proposed conquers several flaws of some former mouse-based TRNGs. At last we take experiments and test the randomness of our algorithm with the NIST statistical test suite; results illustrate that our TRNG is suitable to produce true random numbers (TRNs) on universal personal computers (PCs).Wang Xingyuan, Qin Xue, and Teng LinCopyright © 2012 Wang Xingyuan et al. All rights reserved.http://www.hindawi.com/journals/mpe/2012/261367/We designed a distributed collision-free formation flight control law in the framework of nonlinear model predictive control. Formation configuration is determined in the virtual reference point coordinate system. Obstacle avoidance is guaranteed by cost penalty, and intervehicle collision avoidance is guaranteed by cost penalty combined with a new priority strategy.Zhou Chao, Shao-Lei Zhou, Lei Ming, and Wen-Guang ZhangCopyright © 2012 Zhou Chao et al. All rights reserved.http://www.hindawi.com/journals/mpe/2012/841092/The distributions of random variables are of interest in many areas of science. In this paper, the probability density function (PDF) and cumulative distribution function (CDF) of ratio of products of two random variables and random variable are derived. Random variables are described with Rayleigh, Nakagami-m, Weibull, and α-μ distributions. An application of obtained results in performance analysis of multihop wireless communication systems in different transmission environments described in detail. The proposed mathematical analysis is also complemented by various graphically presented numerical results.Edis Mekić, Mihajlo Stefanović, Petar Spalević, Nikola Sekulović, and Ana StankovićCopyright © 2012 Edis Mekić et al. All rights reserved.http://www.hindawi.com/journals/mpe/2012/831956/We deal with finite-buffer queueing systems fed by a Markovian point process. This class includes the queues of type M/G/1/N, MX/G/1/N, PH/G/1/N, MMPP/G/1/N, MAP/G/1/N, and BMAP/G/1/N and is commonly used in the performance evaluation of network traffic buffering processes. Typically, such queueing systems are studied in the stationary regime using matrix-analytic methods connected with M/G/1-type Markov processes. Herein, another method for finding transient and stationary characteristics of these queues is presented. The approach is based on finding a closed-form formula for the Laplace transform of the time-dependent performance measure of interest. The method can be used for finding all basic characteristics like queue size distribution, workload distribution, loss ratio, time to buffer overflow, and so forth. To demonstrate this, several examples for different combinations of arrival processes and characteristics are presented. In addition, the most complex results are illustrated via numerical calculations based on an IP traffic parameterization.Andrzej ChydzinskiCopyright © 2012 Andrzej Chydzinski. All rights reserved.http://www.hindawi.com/journals/mpe/2012/184253/A direct two-point block one-step method for solving general second-order ordinary differential equations (ODEs) directly is presented in this paper. The one-step block method will solve the second-order ODEs without reducing to first-order equations. The direct solutions of the general second-order ODEs will be calculated at two points simultaneously using variable step size. The method is formulated using the linear multistep method, but the new method possesses the desirable feature of the one-step method. The implementation is based on the predictor and corrector formulas in the PE(CE)m mode. The stability and precision of this method will also be analyzed and deliberated. Numerical results are given to show the efficiency of the proposed method and will be compared with the existing method.Zanariah Abdul Majid, Nur Zahidah Mokhtar, and Mohamed SuleimanCopyright © 2012 Zanariah Abdul Majid et al. All rights reserved.http://www.hindawi.com/journals/mpe/2012/904183/We consider the problem of identification of the unknown source in a heat equation. The problem is ill posed in the sense that the solution (if it exists) does not depend continuously on the data. Meyer wavelets have the property that their Fourier transform has compact support. Therefore, by expanding the data and the solution in the basis of the Meyer wavelets, high-frequency components can be filtered away. Under the additional assumptions concerning the smoothness of the solution, we discuss the stability and convergence of a wavelet-Galerkin method for the source identification problem. Numerical examples are presented to verify the efficiency and accuracy of the method.Fangfang DouCopyright © 2012 Fangfang Dou. All rights reserved.http://www.hindawi.com/journals/mpe/2012/216297/A dynamic stationary semianalytical solution for a spatially constant load applied over a rectangular surface within a viscoelastic isotropic full space is presented. The solution is obtained within the frame of a double Fourier integral transform. Closed-form solutions for general loadings within the full space are furnished in the transformed wave number domain. Expressions for three boundary value problems, associated to a normal and two tangential rectangular loadings in the original physical space, are given in terms of a double inverse Fourier integral. These inverse integral transforms must be evaluated numerically. In the second part of the present paper a strategy to evaluate these integrals is described, the procedure validated and a number of original results are reported.Euclides Mesquita, Edivaldo Romanini, and Josue LabakiCopyright © 2012 Euclides Mesquita et al. All rights reserved.http://www.hindawi.com/journals/mpe/2012/515367/In part I of the present article the formulation for a dynamic stationary semianalytical solution for a spatially constant load applied over a rectangular surface within a viscoelastic isotropic full-space has been presented. The solution is obtained within the frame of a double Fourier integral transform. These inverse integral transforms must be evaluated numerically. In the present paper, the technique to evaluate numerically the inverse double Fourier integrals is described. The procedure is validated, and a number of original displacement results for the stationary loading case are reported.Josue Labaki, Edivaldo Romanini, and Euclides MesquitaCopyright © 2012 Josue Labaki et al. All rights reserved.http://www.hindawi.com/journals/mpe/2012/746872/We study the periodic boundary value problem for semilinear fractional differential equations in an ordered Banach space. The method of upper and lower solutions is then extended. The results on the existence of minimal and maximal mild solutions are obtained by using the characteristics of positive operators semigroup and the monotone iterative scheme. The results are illustrated by means of a fractional parabolic partial differential equations.Jia Mu and Yongxiang LiCopyright © 2012 Jia Mu and Yongxiang Li. All rights reserved.http://www.hindawi.com/journals/mpe/2012/861508/Viscoelastic Walters' B fluid flows for three problems, stagnation-point flow, Blasius flow, and Sakiadis flow, have been investigated. In each problem, Cauchy equations are changed to a nondimensional differential equations using stream functions and with assumption of boundary layer flow. The fourth-order predictor-corrector finite-difference method for solving these nonlinear differential equations has been employed. The results that have been obtained using this method are compared with the results of the last studies, and it is clarified that this method is more accurate. It is also shown that the results of last study about Sakiadis flow of Walter's B fluid are not true. In addition, the effects of order of discretization in the boundaries are investigated. Moreover, it has been discussed about the valid region of Weissenberg numbers for the second-order approximation of viscoelastic fluids in each case of study.Seyed Ali Madani Tonekaboni, Ramin Abkar, and Reza KhoeilarCopyright © 2012 Seyed Ali Madani Tonekaboni et al. All rights reserved.http://www.hindawi.com/journals/mpe/2012/128379/Operators of parking guidance and information systems (PGIS) often encounter difficulty in determining when and how to provide reliable car park availability information to drivers. Reliability has become a key factor to ensure the benefits of urban PGIS. The present paper is the first to define the guiding parking reliability of urban parking variable message signs (VMSs). By analyzing the parking choice under guiding and optional parking lots, a guiding parking reliability model was constructed. A mathematical program was formulated to determine the guiding parking reliability of VMS. The procedures were applied to a numerical example, and the factors that affect guiding reliability were analyzed. The quantitative changes of the parking berths and the display conditions of VMS were found to be the most important factors influencing guiding reliability. The parking guiding VMS achieved the best benefit when the parking supply was close to or was less than the demand. The combination of a guiding parking reliability model and parking choice behavior offers potential for PGIS operators to reduce traffic congestion in central city areas.Zhenyu Mei, Ye Tian, and Dongping LiCopyright © 2012 Zhenyu Mei et al. All rights reserved.http://www.hindawi.com/journals/mpe/2012/345461/This paper presents a large deflection of variable-arc-length beams, which are made from nonlinear elastic materials, subjected to its uniform self-weight. The stress-strain relation of materials obeys the Ludwick constitutive law. The governing equations of this problem, which are the nonlinear differential equations, are derived by considering the equilibrium of a differential beam element and geometric relations of a beam segment. The model formulation presented herein can be applied to several types of nonlinear elastica problems. With presence of geometric and material nonlinearities, the system of nonlinear differential equations becomes complicated. Consequently, the numerical method plays an important role in finding solutions of the presented problem. In this study, the shooting optimization technique is employed to compute the numerical solutions. From the results, it is found that there is a critical self-weight of the beam for each value of a material constant n. Two possible equilibrium configurations (i.e., stable and unstable configurations) can be found when the uniform self-weight is less than its critical value. The relationship between the material constant n and the critical self-weight of the beam is also presented.Chainarong Athisakul, Boonchai Phungpaingam, Gissanachai Juntarakong, and Somchai ChucheepsakulCopyright © 2012 Chainarong Athisakul et al. All rights reserved.http://www.hindawi.com/journals/mpe/2012/393204/The application of Transfer matrix method (TMM) ranges from linear/nonlinear vibration, composite structure, and multibody system to calculating static deformation, natural vibration, dynamical response, and damage identification. Generally TMM has two characteristics: (1) the TMM formulae share similarity to the chain mechanics model in terms of topology structure; then TMM often is selected as a powerful tool to analyze the chain system. (2) TMM is adopted to deal with the problems of the discrete system, continuous system, and especial discrete/continuous coupling system with the uniform matrix form. In this investigation, a novel TMM is proposed to analyze the natural vibration of the tree system. In order to make the TMM of the tree system have the two above advantages of the TMM of the chain system, the suitable state vectors and transfer matrices of the typical components of the tree system are constructed. Then the topology comparability between the mechanics model and its corresponding formulae of TMM can be adopted to assembling the transfer matrices and transfer equations of the global tree system. Two examples of natural vibration problems validating the method are given. The formulation of the proposed TMM is mathematically intuitive and can be held and applied by the engineers easily.Bin He, Xiaoting Rui, and Huiling ZhangCopyright © 2012 Bin He et al. All rights reserved.http://www.hindawi.com/journals/mpe/2012/254346/The leather nesting problem is a cutting and packing optimization problem that consists in finding the best layout for a set of irregular pieces within a natural leather hide with an irregular surface and contour. In this paper, we address a real application of this problem related to the production of car seats in the automotive industry. The high quality requirements imposed on these products combined with the heterogeneity of the leather hides make the problem very complex to solve in practice. Very few results are reported in the literature for the leather nesting problem. Furthermore, the majority of the approaches impose some additional constraints to the layouts related to the particular application that is considered. In this paper, we describe a variable neighborhood search algorithm for the general leather nesting problem. To evaluate the performance of our approaches, we conducted an extensive set of computational experiments on real instances. The results of these experiments are reported at the end of the paper.Cláudio Alves, Pedro Brás, José M. Valério de Carvalho, and Telmo PintoCopyright © 2012 Cláudio Alves et al. All rights reserved.http://www.hindawi.com/journals/mpe/2012/248175/This paper describes the use of integer and fractional electrical elements, for modelling two electrochemical systems. A first type of system consists of botanical elements and a second type is implemented by electrolyte processes with fractal electrodes. Experimental results are analyzed in the frequency domain, and the pros and cons of adopting fractional-order electrical components for modelling these systems are compared.Isabel S. Jesus and J. A. Tenreiro MachadoCopyright © 2012 Isabel S. Jesus and J. A. Tenreiro Machado. All rights reserved.http://www.hindawi.com/journals/mpe/2012/346951/Hand gesture recognition is a topic in artificial intelligence and computer vision with the goal to automatically interpret human hand gestures via some algorithms. Notice that it is a difficult classification task for which only one simple classifier cannot achieve satisfactory performance; several classifier combination techniques are employed in this paper to handle this specific problem. Based on some related data at hand, AdaBoost and rotation forest are seen to behave significantly better than all the other considered algorithms, especially a classification tree. By investigating the bias-variance decompositions of error for all the compared algorithms, the success of AdaBoost and rotation forest can be attributed to the fact that each of them simultaneously reduces the bias and variance terms of a SingleTree's error to a large extent. Meanwhile, kappa-error diagrams are utilized to study the diversity-accuracy patterns of the constructed ensemble classifiers in a visual manner.Guan-Wei Wang, Chunxia Zhang, and Jian ZhuangCopyright © 2012 Guan-Wei Wang et al. All rights reserved.http://www.hindawi.com/journals/mpe/2012/905495/Hand recognition is one of the popular biometry methods for access control systems. In this paper, a new scheme for personal recognition using thermal images of the hand and an extension neural network (ENN) is presented. The features of the recognition system are extracted from gray level hand images, which are taken by an infrared camera. The main advantage of the thermal image is that it can reduce errors and noise in the features extracted stage, which is most important to increase the accuracy of recognition systems. Moreover, a new recognition method based on the ENN is proposed to perform the core functions of the hand recognition system. The proposed ENN-based recognition method also permits rapid adaptive processing for a new pattern, as it only tunes the boundaries of classified features or adds a new neural node. It is feasible to implement the proposed method on a Microcomputer for a portable personal recognition device. From the tested examples, the proposed method has a significantly high degree of recognition accuracy and shows good tolerance to errors added.Meng-Hui WangCopyright © 2012 Meng-Hui Wang. All rights reserved.http://www.hindawi.com/journals/mpe/2012/535610/We consider multitarget linear-quadratic control problem on semi-infinite interval. We show that the problem can be reduced to a simple convex optimization problem on the simplex.L. Faybusovich and T. MouktonglangCopyright © 2012 L. Faybusovich and T. Mouktonglang. All rights reserved.http://www.hindawi.com/journals/mpe/2012/351901/The ongoing controversy about in what condition should we set the curb parking has few definitive answers because comprehensive research in this area has been lacking. Our goal is to present a set of heuristic urban street speed functions under mixed traffic flow by taking into account impacts of curb parking. Two impacts have been defined to classify and quantify the phenomena of motor vehicles' speed dynamics in terms of curb parking. The first impact is called Space impact, which is caused by the curb parking types. The other one is the Time impact, which results from the driver maneuvering in or out of parking space. In this paper, based on the empirical data collected from six typical urban streets in Nanjing, China, two models have been proposed to describe these phenomena for one-way traffic and two-way traffic, respectively. An intensive experiment has been conducted in order to calibrate and validate these proposed models, by taking into account the complexity of the model parameters. We also provide guidelines in terms of how to cluster and calculate those models' parameters. Results from these models demonstrated promising performance of modeling motor vehicles' speed for mixed traffic flow under the influence of curb parking.Zhenyu Mei and Jun ChenCopyright © 2012 Zhenyu Mei and Jun Chen. All rights reserved.http://www.hindawi.com/journals/mpe/2012/472575/This paper presents an inverse problem and its solution procedure, which are aimed at identifying a sudden underwater movement of the sea bottom. The identification is mathematically shown to work with a known snapshot data of generated water wave configurations. It is also proved that the problem has a unique solution. However, the inverse problem is involved in an integral equation of the first kind, resulting in an ill-posed problem in the sense of stability. That is, the problem lacks solution stability properties. To overcome the difficulty of solution instability, in this paper, a stabilization technique, called regularization, is incorporated in the present solution procedure for the identification of the sea bottom movement. A numerical experiment is presented to demonstrate that the proposed (numerical) solution procedure operates.T. S. Jang, Hong Gun Sung, and Jinsoo ParkCopyright © 2012 T. S. Jang et al. All rights reserved.http://www.hindawi.com/journals/mpe/2012/670723/Permeability is a key parameter associated with the characterization of any hydrocarbon reservoir. In fact, it is not possible to have accurate solutions to many petroleum engineering problems without having accurate permeability value. The conventional methods for permeability determination are core analysis and well test techniques. These methods are very expensive and time consuming. Therefore, attempts have usually been carried out to use artificial neural network for identification of the relationship between the well log data and core permeability. In this way, recent works on artificial intelligence techniques have led to introduce a robust machine learning methodology called support vector machine. This paper aims to utilize the SVM for predicting the permeability of three gas wells in the Southern Pars field. Obtained results of SVM showed that the correlation coefficient between core and predicted permeability is 0.97 for testing dataset. Comparing the result of SVM with that of a general regression neural network (GRNN) revealed that the SVM approach is faster and more accurate than the GRNN in prediction of hydrocarbon reservoirs permeability.R. Gholami, A. R. Shahraki, and M. Jamali PaghalehCopyright © 2012 R. Gholami et al. All rights reserved.http://www.hindawi.com/journals/mpe/2012/490649/The way for performing multiple sequence alignment is based on the criterion of the maximum-scored information content computed from a weight matrix, but it is possible to have two or more alignments to have the same highest score leading to ambiguities in selecting the best alignment. This paper addresses this issue by introducing the concept of joint weight matrix to eliminate the randomness in selecting the best multiple sequence alignment. Alignments with equal scores are iteratively rescored with the joint weight matrix of increasing level (nucleotide pairs, triplets, and so on) until one single best alignment is eventually found. This method for resolving ambiguity in multiple sequence alignment can be easily implemented by use of the improved scoring matrix.Jian-Jun Shu, Kian Yan Yong, and Weng Kong ChanCopyright © 2012 Jian-Jun Shu et al. All rights reserved.http://www.hindawi.com/journals/mpe/2012/383248/To evaluate how much two different complex topologies are similar to each other in a quantitative way is an essential procedure in large-scale topology researches and still remains an NP problem. Cross-correlation evaluation model (CCEM) together with Genetic Algorithm (GA) is introduced in this paper trying to solve this issue. Experiments have proved that SLS (Signless Laplacian Spectra) is capable of identifying a topology structure and CCEM is capable of distinguishing the differences between corresponding topology SLS eigenvectors. CCEM used in GA is recommended at last since a way of not finding the optimum solution in GA is a good way to reduce computing complexity.Ye Xu and Zhuo WangCopyright © 2012 Ye Xu and Zhuo Wang. All rights reserved.http://www.hindawi.com/journals/mpe/2012/791026/A new method is suggested for obtaining the exact and numerical solutions of the initial-boundary value problem for a nonlinear parabolic type equation in the domain with the free boundary. With this aim, a special auxiliary problem having some advantages over the main problem and being equivalent to the main problem in a definite sense is introduced. The auxiliary problem allows us to obtain the weak solution in a class of discontinuous functions. Moreover, on the basis of the auxiliary problem a higher-resolution numerical method is developed so that the solution accurately describes all physical properties of the problem. In order to extract the significance of the numerical solutions obtained by using the suggested auxiliary problem, some computer experiments are carried out.Bahaddin SinsoysalCopyright © 2012 Bahaddin Sinsoysal. All rights reserved.http://www.hindawi.com/journals/mpe/2012/834807/Radiofrequency (RF) ablation with internally cooled needle-like electrodes is widely used in medical techniques such as tumor ablation. The device consists of a metallic electrode with an internal liquid cooling system that cools the electrode surface. Theoretical modeling is a rapid and inexpensive way of studying different aspects of the RF ablation process by the bioheat equation, and the analytical approach provides an exact solution to the thermal problem. Our aim was to solve analytically the RF ablation transient time problem with a needle-like internally cooled cylindrical electrode while considering the blood perfusion term. The results showed that the maximal tissue temperature is reached ≈3 mm from the electrode, which confirms previous experimental findings. We also observed that the temperature distributions were similar for three coolant temperature values (5∘C, 15∘C, and 25∘C). The differences were only notable in temperature very close to the probe. Finally, considering the 50∘C line as a thermal lesion mark, we found that lesion diameter was around 2 cm, which is exactly that observed experimentally in perfused hepatic tissue and slightly smaller than that observed in nonperfused (ex vivo) hepatic tissue.Juan A. López Molina, María J. Rivera, and Enrique BerjanoCopyright © 2012 Juan A. López Molina et al. All rights reserved.http://www.hindawi.com/journals/mpe/2012/347675/We study a multistate model for an aging piece of equipment under condition-based maintenance and apply an expectation maximization algorithm to obtain maximum likelihood estimates of the model parameters. Because of the monitoring discontinuity, we cannot observe any state's duration. The observation consists of the equipment's state at an inspection or right after a repair. Based on a proper construction of stochastic processes involved in the model, calculation of some probabilities and expectations becomes tractable. Using these probabilities and expectations, we can apply an expectation maximization algorithm to estimate the parameters in the model. We carry out simulation studies to test the accuracy and the efficiency of the algorithm.Qihong Duan, Xiang Chen, Dengfu Zhao, and Zheng ZhaoCopyright © 2012 Qihong Duan et al. All rights reserved.http://www.hindawi.com/journals/mpe/2012/601309/We, for the first time, investigate the basic behaviours of a chaotic switching fractional system via both theoretical and numerical ways. To deeply understand the mechanism of the chaos generation, we also analyse the parameterization of the switching fractional system and the dynamics of the system's trajectory. Then we try to write down some detailed rules for designing chaotic or chaos-like systems by switching fractional systems, which can be used in the future application. At last, for the first time, we proposed a new switching fractional system, which can generate three attractors with the positive largest Lyapunov exponent.Wang Xingyuan and Qin XueCopyright © 2012 Wang Xingyuan and Qin Xue. All rights reserved.http://www.hindawi.com/journals/mpe/2012/710834/We discuss dynamic system performance evaluation in the river port utilizing queuing models with batch arrivals. The general models of the system are developed. This system is modelled by MX/M/n/m queue with finite waiting areas and identical and independent cargo-handling capacities. The models are considered with whole and part batch acceptance (or whole and part batch rejections) and the interarrival and service times are exponentially distributed. Results related to the batch blocking probability and the blocking probability of an arbitrary vessel in nonstationary and stationary states have been obtained. Numerical results and computational experiments are reported to evaluate the efficiency of the models for the real system.Branislav Dragović, Nam-Kyu Park, Nenad Đ. Zrnić, and Romeo MeštrovićCopyright © 2012 Branislav Dragović et al. All rights reserved.http://www.hindawi.com/journals/mpe/2012/301971/In this paper, we present a fast algorithm of Moore-Penrose inverse for m×n Loewner-type matrix with full column rank by forming a special block matrix and studying its inverse. Its computation complexity is O(mn)+O(n2), but it is O(mn2)+O(n3) by using L+=(LTL)−1LT.QiuJuan Tong, SanYang Liu, and Quan LuCopyright © 2012 QiuJuan Tong et al. All rights reserved.http://www.hindawi.com/journals/mpe/2012/939717/We study a maximization problem: online scheduling on m identical machines to maximize the number of early jobs. The problem is online in the sense that all jobs arrive over time. Each job's characteristics, such as processing time and due date, become known at its arrival time. We consider the preemption-restart model, in which preemption is allowed, while once a job is restarted, it loses all the progress that has been made on this job so far. If in some schedule a job is completed before or at its due date, then it is called early (or on time). The objective is to maximize the number of early jobs. For m identical machines, we prove an upper bound 1-(1/2m) of competitive ratio and show that ECT (earliest completion time) algorithm is 1/2-competitive.Feifeng Zheng, Ming Liu, Chengbin Chu, and Yinfeng XuCopyright © 2012 Feifeng Zheng et al. All rights reserved.