Mathematical Problems in Engineering http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2015 , Hindawi Publishing Corporation . All rights reserved. An Enhanced Quantum-Behaved Particle Swarm Algorithm for Reactive Power Optimization considering Distributed Generation Penetration Thu, 03 Sep 2015 11:44:34 +0000 http://www.hindawi.com/journals/mpe/2015/342080/ This paper puts forward a novel particle swarm optimization algorithm with quantum behavior (QPSO) to solve reactive power optimization in power system with distributed generation. Moreover, differential evolution (DE) operators are applied to enhance the algorithm (DQPSO). This paper focuses on the minimization of active power loss, respectively, and uses QPSO and DQPSO to determine terminal voltage of generators, and ratio of transformers, switching group number of capacitors to achieve optimal reactive power flow. The proposed algorithms are validated through three IEEE standard examples. Comparing the results obtained from QPSO and DQPSO with those obtained from PSO, we find that our algorithms are more likely to get the global optimal solution and have a better convergence. What is more, DQPSO is better than QPSO. Furthermore, with the integration of distributed generation, active power loss has decreased significantly. Specifically, PV distributed generations can suppress voltage fluctuation better than PQ distributed generations. Runhai Jiao, Bo Li, Yuancheng Li, and Lingzhi Zhu Copyright © 2015 Runhai Jiao et al. All rights reserved. Design of an Integrated Vehicle Chassis Control System with Driver Behavior Identification Thu, 03 Sep 2015 10:42:29 +0000 http://www.hindawi.com/journals/mpe/2015/954514/ An integrated vehicle chassis control strategy with driver behavior identification is introduced in this paper. In order to identify the different types of driver behavior characteristics, a driver behavior signals acquisition system was established using the dSPACE real-time simulation platform, and the driver inputs of 30 test drivers were collected under the double lane change test condition. Then, driver behavior characteristics were analyzed and identified based on the preview optimal curvature model through genetic algorithm and neural network method. Using it as a base, an integrated chassis control strategy with active front steering (AFS) and direct yaw moment control (DYC) considering driver characteristics was established by model predictive control (MPC) method. Finally, simulations were carried out to verify the control strategy by CarSim and MATLAB/Simulink. The results show that the proposed method enables the control system to adjust its parameters according to the driver behavior identification results and the vehicle handling and stability performance are significantly improved. Bing Zhu, Yizhou Chen, Jian Zhao, and Yunfu Su Copyright © 2015 Bing Zhu et al. All rights reserved. Flocking Control of Multiple Mobile Agents with the Rules of Avoiding Collision Thu, 03 Sep 2015 09:07:16 +0000 http://www.hindawi.com/journals/mpe/2015/529538/ This paper investigates the flocking and the coordinative control problems of multiple mobile agents with the rules of avoiding collision. We propose a set of control laws using hysteresis in adding new links and applying new potential function to guarantee that the fragmentation of the network can be avoided, under which all agents approach a common velocity vector, and asymptotically converge to a fixed value of interagent distances and collisions between agents can be avoided throughout the motion. Furthermore, we extend the flocking algorithm to solve the flocking situation of the group with a virtual leader agent. The laws can make all agents asymptotically approach the virtual leader and collisions can be avoided between agents in the motion evolution. Finally, some numerical simulations are showed to illustrate the theoretical results. Hongtao Zhou, Wenfeng Zhou, and Wei Zeng Copyright © 2015 Hongtao Zhou et al. All rights reserved. A Nonpolynomial Optimal Algorithm for Sequencing Inspectors in a Repeat Inspection System with Rework Thu, 03 Sep 2015 07:00:58 +0000 http://www.hindawi.com/journals/mpe/2015/601029/ Assuming that two types of inspection errors are nonidentical and that only the items rejected by an inspector are reworked and sent to the next inspection cycle, we formulate a combinatorial optimization problem for simultaneously determining both the minimum frequency of inspection-rework cycles and the optimal sequence of inspectors selected from a set of available inspectors, in order to meet the constraints of the outgoing quality level. Based on the inherent properties from our mathematical model, we provide a nonpolynomial optimal algorithm with a time complexity of . Moon Hee Yang and Jae Hyung Cho Copyright © 2015 Moon Hee Yang and Jae Hyung Cho. All rights reserved. Modeling and Stability Analysis of Worm Propagation in Wireless Sensor Network Wed, 02 Sep 2015 14:20:21 +0000 http://www.hindawi.com/journals/mpe/2015/129598/ An improved SIRS model considering communication radius and distributed density of nodes is proposed. The proposed model captures both the spatial and temporal dynamics of worms spread process. Using differential dynamical theories, we investigate dynamics of worm propagation to time in wireless sensor networks (WSNs). Reproductive number which determines global dynamics of worm propagation in WSNs is obtained. Equilibriums and their stabilities are also found. If reproductive number is less than one, the infected fraction of the sensor nodes disappears and if the reproduction number is greater than one, the infected fraction asymptotically stabilizes at the endemic equilibrium. Based on the reproduction number, we discuss the threshold of worm propagation about communication radius and distributed density of nodes in WSNs. Finally, numerical simulations verify the correctness of theoretical analysis. Liping Feng, Lipeng Song, Qingshan Zhao, and Hongbin Wang Copyright © 2015 Liping Feng et al. All rights reserved. Customers’ Mode Choice Behaviors of Express Service Based on Latent Class Analysis and Logit Model Wed, 02 Sep 2015 13:43:10 +0000 http://www.hindawi.com/journals/mpe/2015/610673/ As the parcel delivery service is booming in China, the competition among express companies intensifies. This paper employed multinomial logit model (MNL) and latent class model (LCM) to investigate customers’ express service choice behavior, using data from a SP survey. The attributes and attribute levels that matter most to express customers are identified. Meanwhile, the customers are divided into two segments (penny pincher segment and high-end segment) characterized by their taste heterogeneity. The results indicate that the LCM performs statistically better than MNL in our sample. Therefore, more attention should be paid to the taste heterogeneity, especially for further academic and policy research in freight choice behavior. Lian Lian, Shuo Zhang, Zhong Wang, Kai Liu, and Lihuan Cao Copyright © 2015 Lian Lian et al. All rights reserved. Integral Sliding Mode Control of Lur’e Singularly Perturbed Systems Wed, 02 Sep 2015 10:49:18 +0000 http://www.hindawi.com/journals/mpe/2015/926762/ This paper investigates the integral sliding mode control problem for Lur’e singularly perturbed systems with sector-constrained nonlinearities. First, we design a proper sliding manifold such that the motion of closed-loop systems with a state feedback controller along the manifold is absolutely stable. To achieve this, we give a matrix inequality-based absolute stability criterion; thus the above problem can be converted into a matrix inequality feasibility problem. In addition, the gain matrix can also be derived by solving the matrix inequality. Then, a discontinuous control law is synthesized to force the system state to reach the sliding manifold and stay there for all subsequent time. Finally, some numerical examples are given to illustrate the effectiveness of the proposed results. Yanyan Wang and Wei Liu Copyright © 2015 Yanyan Wang and Wei Liu. All rights reserved. Bent and Permutational Properties of Budaghyan-Carlet Hexanomials Wed, 02 Sep 2015 08:30:10 +0000 http://www.hindawi.com/journals/mpe/2015/467020/ The set related to the existence of Budaghyan-Carlet hexanomials is characterized. By investigating the component functions, it is also proved that none of Budaghyan-Carlet hexanomials cannot be turned into a permutation by adding any linearized polynomial. As a byproduct, a class of quadratic bent functions is obtained. Tao Xie Copyright © 2015 Tao Xie. All rights reserved. Distributed Multiagent for NAO Robot Joint Position Control Based on Echo State Network Tue, 01 Sep 2015 11:54:55 +0000 http://www.hindawi.com/journals/mpe/2015/945493/ Based on echo state networks, the joints position control of NAO robot is studied in this paper. The process to control the robot position can be divided into two phases. The senor parameters are released during the first phase. Depending on the dynamic coupling effect between the angle acceleration of passive joint and the torque of active joint, passive joint can be controlled indirectly to the desired position along the desired trajectory. The ESN control rules during the first phase are described and ESN controller is designed to control the motion of passive joint. The brake is locked during the second phase; then active joint is controlled to the desired position. The experimental control system based on PMAC controller is designed and developed. Finally, the joint position control of the NAO robot is achieved successfully by experiments. Echo state networks utilized incremental updates driven by new sensor readings and massive short memory with history inputs; thus varying communication rates can help imitate human upper limb motion based on wearable sensors to obtain human joint angles. Ling Qin and Bo Lei Copyright © 2015 Ling Qin and Bo Lei. All rights reserved. Pull-In Analysis of the Flat Circular CMUT Cell Featuring Sealed Cavity Tue, 01 Sep 2015 11:44:06 +0000 http://www.hindawi.com/journals/mpe/2015/150279/ Capacitive micromachined ultrasonic transducers (CMUTs) are one of the appealing MEMS devices. Most studies treat CMUTs as rigid plates vibrating in open air, ignoring the mechanical boundary conditions for simplification and resulting in cumulative errors in coupled fields. This paper presents a new analytical model for the pull-in characteristics of the flat circular CMUT cell featuring sealed cavity. Utilizing the plate theory coupled with Boyle’s law, the paper establishes a strong relation between the pressures inside the sealed cavity and the pull-in characteristics for the first time. Not only did we point out that the existence of the pressure inside the sealed cavity cannot be omitted, but we also quantified the direct effect of the pressure ratios on the pull-in phenomenon. The pull-in voltages increase while the pull-in ratios decrease with the pressure ratios of the pressure inside the sealed cavity to the ambient pressure. The proposed calculation process delivers a good approximation of the pull-in voltages and displacements, which are consistent with COMSOL simulation results. Particularly, the percentage error of our calculation process is 6.986% for the worst case. Therefore, our proposed analytical model accurately and efficiently predicts the pull-in characteristics and this paper offers new perspectives and reference value in designing and modeling the CMUTs. Wen Zhang, Hui Zhang, Fei Du, Jianchao Shi, Shijiu Jin, and Zhoumo Zeng Copyright © 2015 Wen Zhang et al. All rights reserved. Multiconstrained QoS Routing Using a Differentially Guided Krill Herd Algorithm in Mobile Ad Hoc Networks Tue, 01 Sep 2015 11:26:09 +0000 http://www.hindawi.com/journals/mpe/2015/862145/ This paper presents a multiconstrained quality-of-service routing (QoSR) based on a differentially guided krill herd (DGKH) algorithm in mobile ad hoc networks (MANETs). QoSR is a NP-complete and significant problem with immense challenges in determining an optimum path that simultaneously satisfies various constraints in MANETs, where the topology varies constantly. Various heuristic algorithms are widely used to solve this problem with compromise on excessive computational complexities and/or low performance. This paper proposes a krill herd based algorithm called DGKH, where the krill individuals do not update the position in comparison with one-to-one (as usual), but instead it uses the information from various krill individuals and then searches to determine a feasible path. Experiment results on MANETs with different number nodes (routes) are considered with three constraints which are maximum allowed delay, maximum allowed jitter, and minimum requested bandwidth. It is demonstrated that the proposed DGKH algorithm is an effective approximation algorithm exhibiting satisfactory performance than the KHA and existing algorithms in the literature by determining an optimum path that satisfies more than one QoS constraint in MANETs. D. Kalaiselvi and R. Radhakrishnan Copyright © 2015 D. Kalaiselvi and R. Radhakrishnan. All rights reserved. Distributed Robust Attitude Tracking of Multiple Spacecraft with Disturbances and Unmodelled Dynamics Tue, 01 Sep 2015 11:21:50 +0000 http://www.hindawi.com/journals/mpe/2015/941697/ This paper considers the distributed robust attitude tracking problem of multiple spacecraft subject to disturbances and unmodelled dynamics. We designed a distributed robust attitude controller for each spacecraft using the relative attitudes and relative angular velocities of neighbors to ensure that the attitude tracking errors between the leader and the followers converge to zero under the condition that the communication graph among the followers is undirected and connected and at least one follower has the access to the leader. The control algorithm achieves robust attitude tracking under the existence of the disturbances and unmodelled dynamics by selecting the control gains according to the given condition. Dapeng Yang and Xiangdong Liu Copyright © 2015 Dapeng Yang and Xiangdong Liu. All rights reserved. Energy-Based Spectrum Sensing under Nonreconstruction Framework Tue, 01 Sep 2015 11:01:43 +0000 http://www.hindawi.com/journals/mpe/2015/259890/ To reduce the computational complexity and rest on less prior knowledge, energy-based spectrum sensing under nonreconstruction framework is studied. Compressed measurements are adopted directly to eliminate the effect of reconstruction error and high computational complexity caused by reconstruction algorithm of compressive sensing. Firstly, we summarize the conventional energy-based spectrum sensing methods. Next, the major effort is placed on obtaining the statistical characteristics of compressed measurements and its corresponding squared form, such as mean, variance, and the probability density function. And then, energy-based spectrum sensing under nonreconstruction framework is addressed and its performance is evaluated theoretically and experimentally. Simulations for the different parameters are performed to verify the performance of the presented algorithm. The theoretical analysis and simulation results reveal that the performance drops slightly less than that of conventional energy-normalization method and reconstruction-based spectrum sensing algorithm, but its computational complexity decreases remarkably, which is the first thing one should think about for practical applications. Accordingly, the presented method is reasonable and effective for fast detection in most cognitive scenarios. Yulong Gao and Yanping Chen Copyright © 2015 Yulong Gao and Yanping Chen. All rights reserved. Effect of Cyclic Loading on the Lateral Behavior of Offshore Monopiles Using the Strain Wedge Model Tue, 01 Sep 2015 09:23:36 +0000 http://www.hindawi.com/journals/mpe/2015/485319/ This paper presents the effect of cyclic loading on the lateral behavior of monopiles in terms of load-displacement curves, deflection curves, and - curves along the pile. A commercial software, Strain Wedge Model (SWM), was employed, simulating a 7.5 m in diameter and 60 m long steel monopile embedded into quartz sands. In order to account for the effect of cyclic loading, accumulated strains were calculated based on the results of drained cyclic triaxial compression tests, and the accumulated strains were combined with static strains representing input strains into the SWM. The input strains were estimated for different numbers of cycles ranging from 1 to 105 and 3 different cyclic lateral loads (25%, 50%, and 75% of static capacity). The lateral displacement at pile head was found to increase with increasing number of cycles and increasing cyclic lateral loads. In order to model these deformations resulting from cyclic loading, the initial stiffness of the - curves has to be significantly reduced. Keunju Kim, Boo Hyun Nam, and Heejung Youn Copyright © 2015 Keunju Kim et al. All rights reserved. A Core Model for Parts Suppliers Selecting Method in Manufacturing Supply Chain Tue, 01 Sep 2015 07:34:16 +0000 http://www.hindawi.com/journals/mpe/2015/530147/ Service-oriented manufacturing is the new development of manufacturing systems, and manufacturing supply chain service is also an important part of the service-oriented manufacturing systems; hence, the optimal selection of parts suppliers becomes one of key problems in the supply chain system. Complex network theories made a rapid progress in recent years, but the classical models such as BA model and WS model can not resolve the widespread problems of manufacturing supply chain, such as the repeated attachment of edge and fixed number of vertices, but edges increased with preferential connectivity, and flexible edges’ probability. A core model is proposed to resolve the problem in the paper: it maps the parts supply relationship as a repeatable core; a vertex’s probability distribution function integrating the edge’s rate and vertex’s degree is put forward; some simulations, such as the growth of core, the degree distribution characteristics, and the impacting of parameter, are carried out in our experiments, and the case study is set also. The paper proposed a novel model to analyze the manufacturing supply chain system from the insights of complex network. Guorong Chen, Jiangyuan Zhao, and Juli Deng Copyright © 2015 Guorong Chen et al. All rights reserved. Economic Analysis of Lagrangian and Genetic Algorithm for the Optimal Capacity Planning of Photovoltaic Generation Tue, 01 Sep 2015 07:31:18 +0000 http://www.hindawi.com/journals/mpe/2015/713417/ The optimal allocation problem for a stand-alone photovoltaic (SPV) generation can be achieved by good compromise between system objective and constraint requirements. The Lagrange technique (LGT) is a traditional method to solve such constrained optimization problem. To consider the nonlinear features of reliability constraints evolving from the consideration of different scenarios, including variations of component cost, load profile and installation location, the implementation of SPV generation planning is time-consuming and conventionally implemented by a probability method. Genetic Algorithm (GA) has been successfully applied to many optimization problems. For the optimal allocation of photovoltaic and battery devices, the cost function minimization is implemented by GA to attain global optimum with relative computation simplicity. Analytical comparisons between the results from LGT and GA were investigated and the performance of simulation was discussed. Different planning scenarios show that GA performs better than the Lagrange optimization technique. Jeeng-Min Ling and Ping-Hsun Liu Copyright © 2015 Jeeng-Min Ling and Ping-Hsun Liu. All rights reserved. Evolutionary Game Analysis of Cooperation between Microgrid and Conventional Grid Mon, 31 Aug 2015 14:05:41 +0000 http://www.hindawi.com/journals/mpe/2015/103206/ This paper employs the evolutionary game theory to analyze the cooperation between microgrid and conventional grid, with the discussion focusing on the factors that influence the game players’ selection of strategies, and additionally makes a numerical simulation analysis. The results of analysis based on the evolutionary game model suggest that the two parties’ undertaking of cooperative strategies and uncooperative strategies during the game is the stable point of their evolution and that the probability of their unanimous choice of cooperative strategies positively correlates with the direct benefits and indirect benefits of their cooperation as well as the government subsidies but negatively correlates with the cooperation costs and spending on cooperation risks. Based on the findings, the paper puts forward a series of policy suggestions aiming to deepen the cooperation between microgrid and conventional grid. Chengrong Pan and Yong Long Copyright © 2015 Chengrong Pan and Yong Long. All rights reserved. Energy-Efficient Node Scheduling Method for Cooperative Target Tracking in Wireless Sensor Networks Mon, 31 Aug 2015 13:06:24 +0000 http://www.hindawi.com/journals/mpe/2015/627479/ Using the sensor nodes to achieve target tracking is a challenging problem in resource-limited wireless sensor networks. The tracking nodes are usually required to consume much energy to improve the tracking performance. In this paper, an energy-efficient node scheduling method is proposed to minimize energy consumption while ensuring the tracking accuracy. Firstly, the Kalman-consensus filter is constructed to improve the tracking accuracy and predict the target position. Based on the predicted position, an adaptive node scheduling mechanism is utilized to adjust the sample interval and the number of active nodes dynamically. Rather than using traditional search algorithm, the scheduling problem is decomposed to decouple the sample interval and number of nodes. And the node index is mapped into real domain to get closed-form solution to decide the active nodes. Thus, the NP-complete nature is avoided in the proposed method. The proposed scheduling method can keep the tracking accuracy while minimizing energy consumption. Simulation results validate its effective performance for target tracking in wireless sensor networks. Weirong Liu, Yun He, Xiaoyong Zhang, Fu Jiang, Kai Gao, and Jianming Xiao Copyright © 2015 Weirong Liu et al. All rights reserved. Adaptive Synchronization via State Predictor on General Complex Dynamic Networks Mon, 31 Aug 2015 12:47:20 +0000 http://www.hindawi.com/journals/mpe/2015/415734/ This paper considers the adaptive synchronization of general complex dynamic networks via state predictor based on the fixed topology for nonlinear dynamical systems. Using Lyapunov stability properties, it is proved that the complex dynamical networks with state predictor are asymptotically stable. Moreover, it is also shown that the rate of convergence of complex dynamical networks with state predictor is faster than the complex dynamical networks without state predictor. Lijun Wang, Pingnan Ruan, Shuang Li, and Xiao Han Copyright © 2015 Lijun Wang et al. All rights reserved. A Novel Scrambling Digital Image Watermark Algorithm Based on Double Transform Domains Mon, 31 Aug 2015 11:34:37 +0000 http://www.hindawi.com/journals/mpe/2015/937432/ Digital watermark technology is a very good method for protecting copyright. In this paper, in terms of requisition of imperceptibility and robustness of watermarking, the multidirectional, multiscale, and band-pass coefficient features of Curvelet transform are introduced and a novel image watermark scheme based on Curvelet and human visual system is proposed. Digital watermark information is embedded into the first 16 directions with larger energy in the fourth layer. Experimental results indicate that the proposed watermark scheme is feasible and simple. Simultaneously, the embedded watermark images just have tiny difference with the original images and the extracted watermark is accurate. Moreover, it is imperceptible and robust against various methods of signals processing such as cropping, noise adding, and rotating and altering. Taiyue Wang and Hongwei Li Copyright © 2015 Taiyue Wang and Hongwei Li. All rights reserved. A Novel Statistical Model for Water Age Estimation in Water Distribution Networks Mon, 31 Aug 2015 11:33:59 +0000 http://www.hindawi.com/journals/mpe/2015/350328/ The water retention time in the water distribution network is an important indicator for water quality. The water age fluctuates with the system demand. The residual chlorine concentration varies with the water age. In general, the concentration of residual chlorine is linearly dependent on the water demand. A novel statistical model using monitoring data of residual chlorine to estimate the nodal water age in water distribution networks is put forward in the present paper. A simplified two-step procedure is proposed to solve this statistical model. It is verified by two virtual systems and a practical application to analyze the water distribution system of Hangzhou city, China. The results agree well with that from EPANET. The model provides a low-cost and reliable solution to evaluate the water retention time. Wei-ping Cheng, En-hua Liu, and Jing-qing Liu Copyright © 2015 Wei-ping Cheng et al. All rights reserved. A Two-Stage Simulated Annealing Algorithm for the Many-to-Many Milk-Run Routing Problem with Pipeline Inventory Cost Mon, 31 Aug 2015 11:32:36 +0000 http://www.hindawi.com/journals/mpe/2015/428925/ In recent years, logistics systems with multiple suppliers and plants in neighboring regions have been flourishing worldwide. However, high logistics costs remain a problem for such systems due to lack of information sharing and cooperation. This paper proposes an extended mathematical model that minimizes transportation and pipeline inventory costs via the many-to-many Milk-run routing mode. Because the problem is NP hard, a two-stage heuristic algorithm is developed by comprehensively considering its characteristics. More specifically, an initial satisfactory solution is generated in the first stage through a greedy heuristic algorithm to minimize the total number of vehicle service nodes and the best insertion heuristic algorithm to determine each vehicle’s route. Then, a simulated annealing algorithm (SA) with limited search scope is used to improve the initial satisfactory solution. Thirty numerical examples are employed to test the proposed algorithms. The experiment results demonstrate the effectiveness of this algorithm. Further, the superiority of the many-to-many transportation mode over other modes is demonstrated via two case studies. Yu Lin, Zheyong Bian, Shujing Sun, and Tianyi Xu Copyright © 2015 Yu Lin et al. All rights reserved. Prediction Method of Bottom Water Coning Profile and Water Breakthrough Time in Bottom Water Reservoir without Barrier Mon, 31 Aug 2015 11:06:43 +0000 http://www.hindawi.com/journals/mpe/2015/149490/ During the exploitation of bottom water oil reservoir, bottom water coning influences the breakthrough of bottom water significantly. Because water cut rises quickly after the breakthrough of bottom water, measures should be taken before the breakthrough to postpone production period without water, thus improving oil recovery. So accurate prediction of water coning profile and breakthrough time is very essential. Through mathematical derivation, this paper proposed a prediction method of bottom water coning profile and bottom water breakthrough time in bottom water reservoir without barrier. Based on theory of fluids flow in porous media, this paper assumes that the flow models are plane radial flow in opened intervals and spherical radial flow in unopened intervals. Further, factors of fluid viscosity, irreducible water saturation, residual oil saturation, and oil-water contact (OWC) movement are also taken into account. Compared with other prediction equations, this method achieves more precise bottom water breakthrough time, and the relative deviation is only 1.14 percent. Yahui Li, Haitao Li, and Ying Li Copyright © 2015 Yahui Li et al. All rights reserved. A Study on Maneuvering Obstacle Motion State Estimation for Intelligent Vehicle Using Adaptive Kalman Filter Based on Current Statistical Model Mon, 31 Aug 2015 09:58:12 +0000 http://www.hindawi.com/journals/mpe/2015/515787/ The obstacle motion state estimation is an essential task in intelligent vehicle. The ASCL group has developed such a system that uses a radar and GPS/INS. When running on the road, the acceleration of the vehicle is always changing, so it is hard for constant velocity (CV) model and constant acceleration (CA) model to describe the motion state of the vehicle. This paper introduced Current Statistical (CS) model from military field, which uses the modified Rayleigh distribution to describe acceleration. The adaptive Kalman filter based on CS model was used to estimate the motion state of the target. We conducted simulation experiments and real vehicle tests, and the results showed that the estimation of position, velocity, and acceleration can be precise. Bao Han, Guan Xin, Jia Xin, and Liu Fan Copyright © 2015 Bao Han et al. All rights reserved. Robust Fault Detection for a Class of Uncertain Nonlinear Systems Based on Multiobjective Optimization Mon, 31 Aug 2015 09:29:03 +0000 http://www.hindawi.com/journals/mpe/2015/705725/ A robust fault detection scheme for a class of nonlinear systems with uncertainty is proposed. The proposed approach utilizes robust control theory and parameter optimization algorithm to design the gain matrix of fault tracking approximator (FTA) for fault detection. The gain matrix of FTA is designed to minimize the effects of system uncertainty on residual signals while maximizing the effects of system faults on residual signals. The design of the gain matrix of FTA takes into account the robustness of residual signals to system uncertainty and sensitivity of residual signals to system faults simultaneously, which leads to a multiobjective optimization problem. Then, the detectability of system faults is rigorously analyzed by investigating the threshold of residual signals. Finally, simulation results are provided to show the validity and applicability of the proposed approach. Bingyong Yan, Huifeng Wang, and Huazhong Wang Copyright © 2015 Bingyong Yan et al. All rights reserved. Combining Independent Component and Grey Relational Analysis for the Real-Time System of Hand Motion Identification Using Bend Sensors and Multichannel Surface EMG Mon, 31 Aug 2015 09:14:52 +0000 http://www.hindawi.com/journals/mpe/2015/329783/ This paper proposes a portable system for hand motion identification (HMI) using the features from data glove with bend sensors and multichannel surface electromyography (SEMG). SEMG could provide the information of muscle activities indirectly for HMI. However it is difficult to discriminate the finger motion like extension of thumb and little finger just using SEMG; the data glove with five bend sensors is designed to detect finger motions in the proposed system. Independent component analysis (ICA) and grey relational analysis (GRA) are used to data reduction and the core of identification, respectively. Six features are extracted from each SEMG channel, and three features are computed from five bend sensors in the data glove. To test the feasibility of the system, this study quantitatively compares the classification accuracies of twenty hand motions collected from 10 subjects. Compared to the performance with a back-propagation neural network and only using GRA method, the proposed method provides equivalent accuracy (>85%) with three training sets and faster processing time (20 ms). The results also demonstrate that ICA can effectively reduce the size of input features with GRA methods and, in turn, reduce the processing time with the low price of reduced identification rates. Pei-Jarn Chen and Yi-Chun Du Copyright © 2015 Pei-Jarn Chen and Yi-Chun Du. All rights reserved. Extremum Seeking Based Fault-Tolerant Cooperative Control for Multiagent Systems Mon, 31 Aug 2015 08:53:00 +0000 http://www.hindawi.com/journals/mpe/2015/783275/ We propose a novel fault-tolerant cooperative control strategy for multiagent systems. A set of unknown input observers for each agent are constructed for fault detection. Then a real-time adaptive extremum seeking algorithm is utilized for adaptive approximation of fault parameter. We prove that the consensus can be still reached by regulating the interconnection weights and changing the connection topology of the fault agent. A numerical simulation example is given to illustrate the feasibility and effectiveness of the proposed method. Fu Jiang, Xiaoyong Zhang, Wentao Yu, Heng Li, Jun Peng, and Yong He Copyright © 2015 Fu Jiang et al. All rights reserved. Impulsive Containment Control in Nonlinear Multiagent Systems with Time-Delay Mon, 31 Aug 2015 08:47:46 +0000 http://www.hindawi.com/journals/mpe/2015/959570/ The containment control problems of nonlinear multiagent systems with time-delay via impulsive algorithms under both fixed and switching topologies are studied. By using the Lyapunov methods, several conditions are derived to achieve the containment control. It is shown that the states of the followers can converge into the convex hull spanned by the states of the leaders if every leader has directed paths to all the followers and the impulsive period is short enough. Finally, some simulations are conducted to verify the effectiveness of the proposed algorithms. Wenshan Hu, Zhenhua Wang, Zhi-Wei Liu, and Hong Zhou Copyright © 2015 Wenshan Hu et al. All rights reserved. Improved Different Dimensional Sensors Combined Space Registration Algorithm Mon, 31 Aug 2015 08:22:25 +0000 http://www.hindawi.com/journals/mpe/2015/289825/ To address the problem of deviation and registration of 3D radar and infrared sensor, this paper presents and improves a method based on the state value and space deviation of federated filtering of unscented Kalman filter and standard Kalman filter, which conduces to real time registering of system deviation of radar and IF sensors. In the method presented here, a covariance matching criteria-based approach was employed for judgment of filtering divergent trend, while self-adaptive attenuation factor was introduced for correction of the predicted error covariance so as to inhibit the divergent phenomenon. The experiment results indicated that the method presented here conduces to improvement of the precision and speed of space registration, showing practical value in deviation registration of 3D radars and infrared sensors. Yuming Bo, Zhimin Chen, Mingfeng Yin, and Tianxiong Wang Copyright © 2015 Yuming Bo et al. All rights reserved. The Study on Detection Method of Water Vapor on Boundary Layer Based on Multiagent System Mon, 31 Aug 2015 08:15:18 +0000 http://www.hindawi.com/journals/mpe/2015/457386/ A method of detecting water vapor on boundary layer based on multiagent system is proposed in this paper. Multiagent system receives electromagnetic signals emitted by the telecommunication base station. Due to the analysis of the actual electromagnetic wave signal propagation path in the atmosphere, atmospheric refraction index and moisture inversion are discussed in this paper. And the feasibility of using electromagnetic detection method is also analyzed. A multiagent system is designed to receive the electromagnetic signals. The composition and function of the multiagent system are clearly described. The atmospheric refractivity is detected by the multiagent system in three weather conditions of sunny, foggy, and rainy days. The results demonstrate the feasibility of water vapor detection method of multiagent system boundary by comparing the result of experiment with traditional method. Xu Dongdong, Zhou Jie, Xia Jingming, Lu Zhenyu, and Huan Hai Copyright © 2015 Xu Dongdong et al. All rights reserved.