Mathematical Problems in Engineering http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2015 , Hindawi Publishing Corporation . All rights reserved. Effect Analysis of Service Supply Chain with Dynamic Game under the Condition of Sensitive Demand Thu, 23 Apr 2015 14:33:23 +0000 http://www.hindawi.com/journals/mpe/2015/278094/ Under the real circumstances of service supply chain, there is one demand appearing as the sensitive feature, to face the increasing uncertainty. It could be elaborated upon the decision variables such as price, quantity, and efforts. The member behaviors are operated and coordinated in the process of multiperiod dynamic game. Based on the multiperiod dynamic game theory, the service demand and price, quantity of goods, and efforts of members in the secondary service supply chain are considered. The paper discusses the reputation effect and ratchet effect in the multiperiod dynamic game service supply chain. Additionally, the paper describes this problem, builds a programming model based on the multiperiod dynamic game, and deduces the optimal solution. Furthermore, the paper analyzes the impact of reputation effect and ratchet effect on the agent’s revenue. Through the simulation, it is found that the agency efforts are a combination result of reputation effect and ratchet effect in the process of multiperiod dynamic game. Through the long-term dynamic game, the short-term moral risk in service supply chain can be restrained so that the result under the asymmetric information is the same as that under the complete information. Guanglan Zhou and Chunhua Ju Copyright © 2015 Guanglan Zhou and Chunhua Ju. All rights reserved. Stochastic Fractional Heat Equations Driven by Fractional Noises Thu, 23 Apr 2015 14:27:47 +0000 http://www.hindawi.com/journals/mpe/2015/421705/ This paper is concerned with the following stochastically fractional heat equation on driven by fractional noise: , where the Hurst parameter and denotes the Skorokhod integral. A unique solution of that equation in an appropriate Hilbert space is constructed. Moreover, the Lyapunov exponent of the solution is estimated, and the Hölder continuity of the solution on both space and time parameters is discussed. On the other hand, the absolute continuity of the solution is also obtained. Xichao Sun and Ming Li Copyright © 2015 Xichao Sun and Ming Li. All rights reserved. Minimum-Energy Wireless Real-Time Multicast by Joint Network Coding and Scheduling Optimization Thu, 23 Apr 2015 14:20:49 +0000 http://www.hindawi.com/journals/mpe/2015/390457/ For real-time multicast services over wireless multihop networks, to minimize the energy of transmissions with satisfying the requirements of a fixed data rate and high reliabilities, we construct a conflict graph based framework by joint optimizing network coding and scheduling. Then, we propose a primal-dual subgradient optimization algorithm by random sampling K maximal stable sets in a given conflict graph. This method transforms the NP-hard scheduling subproblem into a normal linear programming problem to obtain an approximate solution. The proposed algorithm only needs to adopt centralized technique for solving the linear programming problem while all of the other computations can be distributed. The simulation results show that, comparing with the existing algorithm, this algorithm can not only achieve about 20% performance gain, but also have better performance in terms of convergence and robustness. Guoping Tan, Yandan Zhu, Yueheng Li, Lili Zhang, and Jing Xu Copyright © 2015 Guoping Tan et al. All rights reserved. A New Approach for Flexible Molecular Docking Based on Swarm Intelligence Thu, 23 Apr 2015 14:11:13 +0000 http://www.hindawi.com/journals/mpe/2015/540186/ Molecular docking methods play an important role in the field of computer-aided drug design. In the work, on the basis of the molecular docking program AutoDock, we present QLDock as a tool for flexible molecular docking. For the energy evaluation, the algorithm uses the binding free energy function that is provided by the AutoDock 4.2 tool. The new search algorithm combines the features of a quantum-behaved particle swarm optimization (QPSO) algorithm and local search method of Solis and Wets for solving the highly flexible protein-ligand docking problem. We compute the interaction of 23 protein-ligand complexes and compare the results with those of the QDock and AutoDock programs. The experimental results show that our approach leads to substantially lower docking energy and higher docking precision in comparison to Lamarckian genetic algorithm and QPSO algorithm alone. QPSO-ls algorithm was able to identify the correct binding mode of 74% of the complexes. In comparison, the accuracy of QPSO and LGA is 52% and 61%, respectively. This difference in performance rises with increasing complexity of the ligand. Thus, the novel algorithm QPSO-ls may be used to dock ligand with many rotatable bonds with high accuracy. Yi Fu, Xiaojun Wu, Zhiguo Chen, Jun Sun, Ji Zhao, and Wenbo Xu Copyright © 2015 Yi Fu et al. All rights reserved. Obtaining Cross Modal Similarity Metric with Deep Neural Architecture Thu, 23 Apr 2015 13:45:09 +0000 http://www.hindawi.com/journals/mpe/2015/293176/ Analyzing complex system with multimodal data, such as image and text, has recently received tremendous attention. Modeling the relationship between different modalities is the key to address this problem. Motivated by recent successful applications of deep neural learning in unimodal data, in this paper, we propose a computational deep neural architecture, bimodal deep architecture (BDA) for measuring the similarity between different modalities. Our proposed BDA architecture has three closely related consecutive components. For image and text modalities, the first component can be constructed using some popular feature extraction methods in their individual modalities. The second component has two types of stacked restricted Boltzmann machines (RBMs). Specifically, for image modality a binary-binary RBM is stacked over a Gaussian-binary RBM; for text modality a binary-binary RBM is stacked over a replicated softmax RBM. In the third component, we come up with a variant autoencoder with a predefined loss function for discriminatively learning the regularity between different modalities. We show experimentally the effectiveness of our approach to the task of classifying image tags on public available datasets. Ruifan Li, Fangxiang Feng, Xiaojie Wang, Peng Lu, and Bohan Li Copyright © 2015 Ruifan Li et al. All rights reserved. Probability Estimation in the Framework of Intuitionistic Fuzzy Evidence Theory Thu, 23 Apr 2015 09:56:34 +0000 http://www.hindawi.com/journals/mpe/2015/412045/ Intuitionistic fuzzy (IF) evidence theory, as an extension of Dempster-Shafer theory of evidence to the intuitionistic fuzzy environment, is exploited to process imprecise and vague information. Since its inception, much interest has been concentrated on IF evidence theory. Many works on the belief functions in IF information systems have appeared. Although belief functions on the IF sets can deal with uncertainty and vagueness well, it is not convenient for decision making. This paper addresses the issue of probability estimation in the framework of IF evidence theory with the hope of making rational decision. Background knowledge about evidence theory, fuzzy set, and IF set is firstly reviewed, followed by introduction of IF evidence theory. Axiomatic properties of probability distribution are then proposed to assist our interpretation. Finally, probability estimations based on fuzzy and IF belief functions together with their proofs are presented. It is verified that the probability estimation method based on IF belief functions is also potentially applicable to classical evidence theory and fuzzy evidence theory. Moreover, IF belief functions can be combined in a convenient way once they are transformed to interval-valued possibilities. Yafei Song and Xiaodan Wang Copyright © 2015 Yafei Song and Xiaodan Wang. All rights reserved. An Improved Gyrocompass Alignment Method for Large Azimuth Misalignment Thu, 23 Apr 2015 08:15:58 +0000 http://www.hindawi.com/journals/mpe/2015/783640/ Due to the impact of the nonlinear factor caused by large azimuth misalignment, the conventional gyrocompass alignment method is hard to favorably meet the requirement of alignment speed under the condition of large azimuth misalignment of INS. In order to solve this problem, an improved gyrocompass alignment method is presented in this paper. The improved method is designed based on the nonlinear model for large azimuth misalignment and performed by opening the azimuth loop. The influence of the nonlinear factor on gyrocompass alignment will be reduced when opening the azimuth loop. Simulation and experimental results show that the initial alignment can be efficiently accomplished through using the improved method in the case of existing large azimuth misalignment, and in the same conditions, the alignment speed of the improved method is faster than that of the conventional one. Wei Gao, Baofeng Lu, Chunyang Yu, and Haiyu Lan Copyright © 2015 Wei Gao et al. All rights reserved. Computational Intelligence Approaches to Robotics, Automation, and Control Wed, 22 Apr 2015 13:15:03 +0000 http://www.hindawi.com/journals/mpe/2015/620275/ Yi Chen, Yun Li, Huosheng Hu, Jun Zhang, Dongbing Gu, and Peter Xu Copyright © 2015 Yi Chen et al. All rights reserved. Nature-Inspired Algorithms and Applications: Selected Papers from CIS2013 Wed, 22 Apr 2015 11:59:43 +0000 http://www.hindawi.com/journals/mpe/2015/641780/ Yuping Wang, Yiu-ming Cheung, Xiao-Zhi Gao, Patrick Wang, and Hailin Liu Copyright © 2015 Yuping Wang et al. All rights reserved. An Improved Method for Generating Cutter Points Based on Required Form Accuracy of the Machining Surface Wed, 22 Apr 2015 11:37:51 +0000 http://www.hindawi.com/journals/mpe/2015/940643/ Recently, freeform surfaces are widely used in optical field. Fabrication of freeform surface optics needs high machining accuracy and high efficiency simultaneously. Using the present ultraprecision manufacturing technologies, the form accuracy of freeform surfaces can reach submicrometric or even nanometer range but at the cost of low efficiency; moreover, the form accuracy cannot be predicted; the number and the position of cutter points cannot be accurately controlled before practical machining. A novel strategy of cutter points distribution is proposed in the paper, which is based on the required accuracy of the freeform surface and the machining efficiency can be improved by eliminating redundant cutter points on the processing trajectory. The new idea is detailed, simulations are conducted, and experiments are done to verify the feasibility of the proposed method in fabricating two sinusoidal ring surfaces. Shijun Ji, Huijuan Yu, and Ji Zhao Copyright © 2015 Shijun Ji et al. All rights reserved. High Performance Computation of a Jet in Crossflow by Lattice Boltzmann Based Parallel Direct Numerical Simulation Wed, 22 Apr 2015 07:23:51 +0000 http://www.hindawi.com/journals/mpe/2015/956827/ Direct numerical simulation (DNS) of a round jet in crossflow based on lattice Boltzmann method (LBM) is carried out on multi-GPU cluster. Data parallel SIMT (single instruction multiple thread) characteristic of GPU matches the parallelism of LBM well, which leads to the high efficiency of GPU on the LBM solver. With present GPU settings (6 Nvidia Tesla K20M), the present DNS simulation can be completed in several hours. A grid system of 1.5 × 108 is adopted and largest jet Reynolds number reaches 3000. The jet-to-free-stream velocity ratio is set as 3.3. The jet is orthogonal to the mainstream flow direction. The validated code shows good agreement with experiments. Vortical structures of CRVP, shear-layer vortices and horseshoe vortices, are presented and analyzed based on velocity fields and vorticity distributions. Turbulent statistical quantities of Reynolds stress are also displayed. Coherent structures are revealed in a very fine resolution based on the second invariant of the velocity gradients. Jiang Lei, Xian Wang, and Gongnan Xie Copyright © 2015 Jiang Lei et al. All rights reserved. The Algorithm for Algorithms: An Evolutionary Algorithm Based on Automatic Designing of Genetic Operators Tue, 21 Apr 2015 13:43:49 +0000 http://www.hindawi.com/journals/mpe/2015/474805/ At present there is a wide range of evolutionary algorithms available to researchers and practitioners. Despite the great diversity of these algorithms, virtually all of the algorithms share one feature: they have been manually designed. A fundamental question is “are there any algorithms that can design evolutionary algorithms automatically?” A more complete definition of the question is “can computer construct an algorithm which will generate algorithms according to the requirement of a problem?” In this paper, a novel evolutionary algorithm based on automatic designing of genetic operators is presented to address these questions. The resulting algorithm not only explores solutions in the problem space like most traditional evolutionary algorithms do, but also automatically generates genetic operators in the operator space. In order to verify the performance of the proposed algorithm, comprehensive experiments on 23 well-known benchmark optimization problems are conducted. The results show that the proposed algorithm can outperform standard differential evolution algorithm in terms of convergence speed and solution accuracy which shows that the algorithm designed automatically by computers can compete with the algorithms designed by human beings. Dazhi Jiang and Zhun Fan Copyright © 2015 Dazhi Jiang and Zhun Fan. All rights reserved. A Study of Prisoner’s Dilemma Game Model with Incomplete Information Tue, 21 Apr 2015 13:34:03 +0000 http://www.hindawi.com/journals/mpe/2015/452042/ Prisoners’ dilemma is a typical game theory issue. In our study, it is regarded as an incomplete information game with unpublicized game strategies. We solve our problem by establishing a machine learning model using Bayes formula. The model established is referred to as the Bayes model. Based on the Bayesian model, we can make the prediction of players’ choices to better complete the unknown information in the game. And we suggest the hash table to make improvement in space and time complexity. We build a game system with several types of game strategy for testing. In double- or multiplayer games, the Bayes model is more superior to other strategy models; the total income using Bayes model is higher than that of other models. Moreover, from the result of the games on the natural model with Bayes model, as well as the natural model with TFT model, it is found that Bayes model accrued more benefits than TFT model on average. This demonstrates that the Bayes model introduced in this study is feasible and effective. Therefore, it provides a novel method of solving incomplete information game problem. Xiuqin Deng and Jiadi Deng Copyright © 2015 Xiuqin Deng and Jiadi Deng. All rights reserved. The Evolutionary Algorithm to Find Robust Pareto-Optimal Solutions over Time Tue, 21 Apr 2015 12:26:03 +0000 http://www.hindawi.com/journals/mpe/2015/814210/ In dynamic multiobjective optimization problems, the environmental parameters change over time, which makes the true pareto fronts shifted. So far, most works of research on dynamic multiobjective optimization methods have concentrated on detecting the changed environment and triggering the population based optimization methods so as to track the moving pareto fronts over time. Yet, in many real-world applications, it is not necessary to find the optimal nondominant solutions in each dynamic environment. To solve this weakness, a novel method called robust pareto-optimal solution over time is proposed. It is in fact to replace the optimal pareto front at each time-varying moment with the series of robust pareto-optimal solutions. This means that each robust solution can fit for more than one time-varying moment. Two metrics, including the average survival time and average robust generational distance, are present to measure the robustness of the robust pareto solution set. Another contribution is to construct the algorithm framework searching for robust pareto-optimal solutions over time based on the survival time. Experimental results indicate that this definition is a more practical and time-saving method of addressing dynamic multiobjective optimization problems changing over time. Meirong Chen, Yinan Guo, Haiyuan Liu, and Chun Wang Copyright © 2015 Meirong Chen et al. All rights reserved. Fractional-Order Controller Design for Oscillatory Fractional Time-Delay Systems Based on the Numerical Inverse Laplace Transform Algorithms Tue, 21 Apr 2015 07:00:40 +0000 http://www.hindawi.com/journals/mpe/2015/917382/ Fractional-order time-delay system is thought to be a kind of oscillatory complex system which could not be controlled efficaciously so far because it does not have an analytical solution when using inverse Laplace transform. In this paper, a type of fractional-order controller based on numerical inverse Laplace transform algorithm INVLAP was proposed for the mentioned systems by searching for the optimal controller parameters with the objective function of ITAE index due to the verified nature that fractional-order controllers were the best means of controlling fractional-order systems. Simulations of step unit tracking and load-disturbance responses of the proposed fractional-order optimal controller (FOPID) and corresponding conventional optimal PID (OPID) controller have been done on three typical kinds of fractional time-delay system with different ratio between time delay () and time constant () and a complex high-order fractional time delay system to verify the availability of the presented control method. Lu Liu, Feng Pan, and Dingyu Xue Copyright © 2015 Lu Liu et al. All rights reserved. Deteriorating Inventory Model for Chilled Food Mon, 20 Apr 2015 13:49:31 +0000 http://www.hindawi.com/journals/mpe/2015/816876/ With many aspects that affect inventory policy, product perishability is a critical aspect of inventory policy. Most goods will deteriorate during storage and their original value will decline or be lost. Therefore, deterioration should be taken into account in inventory practice. Chilled food products are very common consumer goods that are, in fact, perishable. If the chilled food quality declines over time customers are less likely to buy it. The value the chilled food retains is, however, closely dependent on its quality. From the vendor’s point of view, quantifying quality and remaining value should be a critical business issue. In consequence, we combined the traditional deterioration model and quality prediction model to develop a new deteriorating inventory model for chilled food products. This new model quantifies food quality and remaining value. The model we propose uses real deterioration rate data, and we regard deterioration rate as temperature-dependent. We provide a numerical example to illustrate the solution. Our model demonstrates that high storage temperatures reduce profits and force shorter order cycles. Ming-Feng Yang and Wei-Chung Tseng Copyright © 2015 Ming-Feng Yang and Wei-Chung Tseng. All rights reserved. Multicriteria Decision Model to Support the Assignment of Storage Location of Products in a Warehouse Mon, 20 Apr 2015 13:12:45 +0000 http://www.hindawi.com/journals/mpe/2015/481950/ The storage of products has a strategic role in the supply chain: an efficient organization of products in appropriate locations enables these products to be moved faster inside the warehouse and logistics channel, which increases the speed of delivery and the competitiveness of enterprises. The aim of this paper is to propose a multicriteria decision support model for ranking products and assigning them to warehouse storage locations. During the structuring of the model, the nature of the problem was defined as multicriteria; therefore, the SMARTER and lexicographic methods were applied. The results showed an ordering of products that allowed their strategic location in a hypothetical nonautomated warehouse. Denilson Dimas da Silva, Natália Veloso Caldas de Vasconcelos, and Cristiano Alexandre Virginio Cavalcante Copyright © 2015 Denilson Dimas da Silva et al. All rights reserved. Integrated Supply Chain Cooperative Inventory Model with Payment Period Being Dependent on Purchasing Price under Defective Rate Condition Mon, 20 Apr 2015 12:19:10 +0000 http://www.hindawi.com/journals/mpe/2015/513435/ In most commercial transactions, the buyer and vendor may usually agree to postpone payment deadline. During such delayed period, the buyer is entitled to keep the products without having to pay the sale price. However, the vendor usually hopes to receive full payment as soon as possible, especially when the transaction involves valuable items; yet, the buyer would offer a higher purchasing price in exchange of a longer postponement. Therefore, we assumed such permissible delayed period is dependent on the purchasing price. As for the manufacturing side, defective products are inevitable from time to time, and not all of those defective products can be repaired. Hence, we would like to add defective production and repair rate to our proposed model and discuss how these factors may affect profits. In addition, holding cost, ordering cost, and transportation cost will also be considered as we develop the integrated inventory model with price-dependent payment period under the possible condition of defective products. We would like to find the maximum of the joint expected total profit for our model and come up with a suitable inventory policy accordingly. In the end, we have also provided a numerical example to clearly illustrate possible solutions. Ming-Feng Yang, Jun-Yuan Kuo, Wei-Hao Chen, and Yi Lin Copyright © 2015 Ming-Feng Yang et al. All rights reserved. Hand Gesture Recognition Using Modified 1$ and Background Subtraction Algorithms Mon, 20 Apr 2015 12:12:29 +0000 http://www.hindawi.com/journals/mpe/2015/741068/ Computers and computerized machines have tremendously penetrated all aspects of our lives. This raises the importance of Human-Computer Interface (HCI). The common HCI techniques still rely on simple devices such as keyboard, mice, and joysticks, which are not enough to convoy the latest technology. Hand gesture has become one of the most important attractive alternatives to existing traditional HCI techniques. This paper proposes a new hand gesture detection system for Human-Computer Interaction using real-time video streaming. This is achieved by removing the background using average background algorithm and the 1$ algorithm for hand’s template matching. Then every hand gesture is translated to commands that can be used to control robot movements. The simulation results show that the proposed algorithm can achieve high detection rate and small recognition time under different light changes, scales, rotation, and background. Hazem Khaled, Samir G. Sayed, El Sayed M. Saad, and Hossam Ali Copyright © 2015 Hazem Khaled et al. All rights reserved. A Multiple Attribute Group Decision Making Approach for Solving Problems with the Assessment of Preference Relations Mon, 20 Apr 2015 12:07:58 +0000 http://www.hindawi.com/journals/mpe/2015/849897/ A number of theoretical approaches to preference relations are used for multiple attribute decision making (MADM) problems, and fuzzy preference relations is one of them. When more than one person is interested in the same MADM problem, it then becomes a multiple attribute group decision making (MAGDM) problem. For both MADM and MAGDM problems, consistency among the preference relations is very important to the result of the final decision. The research reported in this paper is based on a procedure that uses a fuzzy preference relations matrix which satisfies additive consistency. This matrix is used to solve multiple attribute group decision making problems. In group decision problems, the assessment provided by different experts may diverge considerably. Therefore, the proposed procedure also takes a heterogeneous group of experts into consideration. Moreover, the methods used to construct the decision matrix and determine the attribution of weight are both introduced. Finally a numerical example is used to test the proposed approach; and the results illustrate that the method is simple, effective, and practical. Taho Yang, Yiyo Kuo, David Parker, and Kuan Hung Chen Copyright © 2015 Taho Yang et al. All rights reserved. A Reversible Steganography Scheme of Secret Image Sharing Based on Cellular Automata and Least Significant Bits Construction Mon, 20 Apr 2015 10:09:00 +0000 http://www.hindawi.com/journals/mpe/2015/849768/ Secret image sharing schemes have been extensively studied by far. However, there are just a few schemes that can restore both the secret image and the cover image losslessly. These schemes have one or more defects in the following aspects: (1) high computation cost; (2) overflow issue existing when modulus operation is used to restore the cover image and the secret image; (3) part of the cover image being severely modified and the stego images having worse visual quality. In this paper, we combine the methods of least significant bits construction (LSBC) and dynamic embedding with one-dimensional cellular automata to propose a new lossless scheme which solves the above issues and can resist differential attack and support parallel computing. Experimental results also show that this scheme has the merit of big embedding capacity. Wei-Tong Hu, Ming-Chu Li, Cheng Guo, and Li-Feng Yuan Copyright © 2015 Wei-Tong Hu et al. All rights reserved. Research and Application of Improved AGP Algorithm for Structural Optimization Based on Feedforward Neural Networks Mon, 20 Apr 2015 09:47:29 +0000 http://www.hindawi.com/journals/mpe/2015/481919/ The adaptive growing and pruning algorithm (AGP) has been improved, and the network pruning is based on the sigmoidal activation value of the node and all the weights of its outgoing connections. The nodes are pruned directly, but those nodes that have internal relation are not removed. The network growing is based on the idea of variance. We directly copy those nodes with high correlation. An improved AGP algorithm (IAGP) is proposed. And it improves the network performance and efficiency. The simulation results show that, compared with the AGP algorithm, the improved method (IAGP) can quickly and accurately predict traffic capacity. Ruliang Wang, Huanlong Sun, Benbo Zha, and Lei Wang Copyright © 2015 Ruliang Wang et al. All rights reserved. Complex Networks: Statistical Properties, Community Structure, and Evolution Mon, 20 Apr 2015 09:29:12 +0000 http://www.hindawi.com/journals/mpe/2015/590794/ We investigate the function for different networks based on complex network theory. In this paper, we choose five data sets from various areas to study. In the study of Chinese network, scale-free effect and hierarchical structure features are found in this complex system. These results indicate that the discovered features of Chinese character structure reflect the combination nature of Chinese characters. In addition, we study the community structure in Chinese character network. We can find that community structure is always considered as one of the most significant features in complex networks, and it plays an important role in the topology and function of the networks. Furthermore, we cut all the nodes in the different networks from low degree to high degree and then obtain many networks with different scale. According to the study, two interesting results have been obtained. First, the relationship between the node number of the maximum communities and the number of communities in the corresponding networks is studied and it is linear. Second, when the number of nodes in the maximum communities is increasing, the increasing tendency of the number of its edges slows down; we predict the complex networks have sparsity. The study effectively explains the characteristic and community structure evolution on different networks. Lei Zhang, Jianxiang Cao, and Jianyu Li Copyright © 2015 Lei Zhang et al. All rights reserved. Emergency Vehicle Scheduling Problem with Time Utility in Disasters Mon, 20 Apr 2015 09:18:35 +0000 http://www.hindawi.com/journals/mpe/2015/164194/ This paper presents a flexible emergency rescue system which is chiefly composed of three parts, namely, disaster assistance center, relief vehicles, and disaster areas. A novel objective of utility maximization is used to evaluate the entire system in disasters. Considering the uncertain road conditions in the relief distribution, we implement triangular fuzzy number to calculate the vehicle velocity. As a consequence, a fuzzy mathematical model is built to maximize the utility of emergency rescue system and then converted to the crisp counterpart. Finally, the results of numerical experiments obtained by particle swarm optimization (PSO) prove the validity of this proposed mathematical model. Xiaobing Gan, Yan Wang, Junbiao Kuang, Ye Yu, and Ben Niu Copyright © 2015 Xiaobing Gan et al. All rights reserved. A Novel Artificial Bee Colony Algorithm for Function Optimization Mon, 20 Apr 2015 08:30:14 +0000 http://www.hindawi.com/journals/mpe/2015/129271/ It is known that both exploration and exploitation are important in the search equations of ABC algorithms. How to well balance the two abilities in the search process is still a challenging problem in ABC algorithms. In this paper, we propose a novel artificial bee algorithm named as “NABC,” by incorporating the information of the global best solution into the solution search equation of the onlookers stage to improve the exploitation. At the same time, we improve the search equation of the employed bees to keep the exploration. The experimental results of NABC tested on a set of 11 numerical benchmark functions show good performance and fast convergence in solving function optimization problems, compared with variant ABC, DE, and PSO algorithms. The application of NABC on solving five standard knapsack problems shows its effectiveness and practicability. Song Zhang and Sanyang Liu Copyright © 2015 Song Zhang and Sanyang Liu. All rights reserved. A Convex-Risk-Measure Based Model and Genetic Algorithm for Portfolio Selection Mon, 20 Apr 2015 08:24:16 +0000 http://www.hindawi.com/journals/mpe/2015/451627/ A convex risk measure called weighted expected shortfall (briefly denoted as WES (Chen and Yang, 2011)) is adopted as the risk measure. This measure can reflect the reasonable risk in the stock markets. Then a portfolio optimization model based on this risk measure is set up. Furthermore, a genetic algorithm is proposed for this portfolio optimization model. At last, simulations are made on randomly chosen ten stocks for 60 days (during January 2, 2014 to April 2, 2014) from Wind database (CFD) in Shenzhen Stock Exchange, and the results indicate that the proposed model is reasonable and the proposed algorithm is effective. Weijia Wang, Jie Hu, and Ning Dong Copyright © 2015 Weijia Wang et al. All rights reserved. Joint Optimization Approach of Maintenance and Production Planning for a Multiple-Product Manufacturing System Mon, 20 Apr 2015 07:24:37 +0000 http://www.hindawi.com/journals/mpe/2015/769723/ This paper deals with the problem of maintenance and production planning for randomly failing multiple-product manufacturing system. The latter consists of one machine which produces several types of products in order to satisfy random demands corresponding to every type of product. At any given time, the machine can only produce one type of product and then switches to another one. The purpose of this study is to establish sequentially an economical production plan and an optimal maintenance strategy, taking into account the influence of the production rate on the system’s degradation. Analytical models are developed in order to find the production plan and the preventive maintenance strategy which minimizes sequentially the total production/inventory cost and then the total maintenance cost. Finally, a numerical example is presented to illustrate the usefulness of the proposed approach. Lahcen Mifdal, Zied Hajej, and Sofiene Dellagi Copyright © 2015 Lahcen Mifdal et al. All rights reserved. KPCA-ESN Soft-Sensor Model of Polymerization Process Optimized by Biogeography-Based Optimization Algorithm Mon, 20 Apr 2015 07:15:36 +0000 http://www.hindawi.com/journals/mpe/2015/493248/ For solving the problem that the conversion rate of vinyl chloride monomer (VCM) is hard for real-time online measurement in the polyvinyl chloride (PVC) polymerization production process, a soft-sensor modeling method based on echo state network (ESN) is put forward. By analyzing PVC polymerization process ten secondary variables are selected as input variables of the soft-sensor model, and the kernel principal component analysis (KPCA) method is carried out on the data preprocessing of input variables, which reduces the dimensions of the high-dimensional data. The -means clustering method is used to divide data samples into several clusters as inputs of each submodel. Then for each submodel the biogeography-based optimization algorithm (BBOA) is used to optimize the structure parameters of the ESN to realize the nonlinear mapping between input and output variables of the soft-sensor model. Finally, the weighted summation of outputs of each submodel is selected as the final output. The simulation results show that the proposed soft-sensor model can significantly improve the prediction precision of conversion rate and conversion velocity in the process of PVC polymerization and can satisfy the real-time control requirement of the PVC polymerization process. Wen-hua Cui, Jie-sheng Wang, and Shu-xia Li Copyright © 2015 Wen-hua Cui et al. All rights reserved. Sampled-Data Control of Nonlinear Systems with Quantization Sun, 19 Apr 2015 14:52:36 +0000 http://www.hindawi.com/journals/mpe/2015/314090/ This paper is concerned with sampled-data control problem for a class of nonlinear systems with input quantization. The nonlinear system is converted into a linear-like system with modeling error by using partition of unity method. A time-dependent Lyapunov functional is introduced to capture the characteristic of nonlinear sampled-data systems and the exponential stability conditions are derived by the use of inequality techniques. The desired sampled-data controller is then synthesized. An example is provided to illustrate the effectiveness and benefits of the proposed scheme. Liu Cui and Dengping Duan Copyright © 2015 Liu Cui and Dengping Duan. All rights reserved. A Line-Based Adaptive-Weight Matching Algorithm Using Loopy Belief Propagation Sun, 19 Apr 2015 12:25:50 +0000 http://www.hindawi.com/journals/mpe/2015/297392/ In traditional adaptive-weight stereo matching, the rectangular shaped support region requires excess memory consumption and time. We propose a novel line-based stereo matching algorithm for obtaining a more accurate disparity map with low computation complexity. This algorithm can be divided into two steps: disparity map initialization and disparity map refinement. In the initialization step, a new adaptive-weight model based on the linear support region is put forward for cost aggregation. In this model, the neural network is used to evaluate the spatial proximity, and the mean-shift segmentation method is used to improve the accuracy of color similarity; the Birchfield pixel dissimilarity function and the census transform are adopted to establish the dissimilarity measurement function. Then the initial disparity map is obtained by loopy belief propagation. In the refinement step, the disparity map is optimized by iterative left-right consistency checking method and segmentation voting method. The parameter values involved in this algorithm are determined with many simulation experiments to further improve the matching effect. Simulation results indicate that this new matching method performs well on standard stereo benchmarks and running time of our algorithm is remarkably lower than that of algorithm with rectangle-shaped support region. Hui Li, Xiao-Guang Zhang, and Zheng Sun Copyright © 2015 Hui Li et al. All rights reserved.