Discrete Dynamics in Nature and Society http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2014 , Hindawi Publishing Corporation . All rights reserved. Nonlinear Analysis on Traffic Flow Based on Catastrophe and Chaos Theory Thu, 27 Nov 2014 12:38:21 +0000 http://www.hindawi.com/journals/ddns/2014/535167/ We applied catastrophe and chaos theory to analyze the traffic nonlinear characteristics of expressway condition. Catastrophe theory was generally used to explore the mathematical relationships among the traffic data collected from highway conditions, which could not be appropriate for the urban expressway conditions. Traffic flow data collected from the 3rd ring road expressway in Beijing was used to build flow-density model and speed-density Greenshields model. Then the density was discussed based on the traffic wave speed function with cusp catastrophe theory; in particular, density conditions on median lanes and shoulder lanes were deeply discussed. Meanwhile the chaotic characteristics were analyzed based on the traffic temporal sequence data collected from 29 detectors located at the 3rd ring road expressway, and C-C method was used to reconstruct the phase space and the largest Lyapunov exponents were estimated by Wolf method and the small data sets method. The results indicated that the traffic operation catastrophe density on the median lanes was a bit higher than that on the shoulder lanes; additionally chaotic characteristics obviously existed in the local corridor composed of 29 detectors in the 3rd ring road expressway traffic flow system. Jian Gu and Shuyan Chen Copyright © 2014 Jian Gu and Shuyan Chen. All rights reserved. An Effective Privacy-Preserving Algorithm Based on Logistic Map and Rubik’s Cube Transformation Thu, 27 Nov 2014 12:14:41 +0000 http://www.hindawi.com/journals/ddns/2014/178585/ Security and privacy issues present a strong barrier for users to adapt to cloud storage systems. In this paper, a new algorithm for data splitting called EPPA is presented to strengthen the confidentiality of data by two-phase process. In EPPA, data object is organized to be several Rubik’s cubes executed for several rounds transformation at the first phase. In every round, chaotic logistic maps generate pseudorandom sequences to cover the plaintext by executing Exclusive-OR operation to form the cipher. Then logistic map is used to create rotation policies to scramble data information based on Rubik’s cube transformation. At the second phase, all cubes are unfolded and combined together as a cross-shaped cube, which will be partitioned into a few data fragments to guarantee that every fragment does not contain continuous bytes. These fragments are stored on randomly chosen servers within cloud environment. Analyses and experiments show that this approach is efficient and useable for the confidentiality of user data in cloud storage system. Wenbin Yao, Pengdi Ye, and Xiaoyong Li Copyright © 2014 Wenbin Yao et al. All rights reserved. A Simple Gaussian Measurement Bound for Exact Recovery of Block-Sparse Signals Wed, 26 Nov 2014 13:56:23 +0000 http://www.hindawi.com/journals/ddns/2014/104709/ We present a probabilistic analysis on conditions of the exact recovery of block-sparse signals whose nonzero elements appear in fixed blocks. We mainly derive a simple lower bound on the necessary number of Gaussian measurements for exact recovery of such block-sparse signals via the mixed norm minimization method. In addition, we present numerical examples to partially support the correctness of the theoretical results. The obtained results extend those known for the standard minimization and the mixed minimization methods to the mixed minimization method in the context of block-sparse signal recovery. Zhi Han, Jianjun Wang, Jia Jing, and Hai Zhang Copyright © 2014 Zhi Han et al. All rights reserved. Radial Basis Function Neural Network with Particle Swarm Optimization Algorithms for Regional Logistics Demand Prediction Wed, 26 Nov 2014 12:48:35 +0000 http://www.hindawi.com/journals/ddns/2014/414058/ Regional logistics prediction is the key step in regional logistics planning and logistics resources rationalization. Since regional economy is the inherent and determinative factor of regional logistics demand, it is feasible to forecast regional logistics demand by investigating economic indicators which can accelerate the harmonious development of regional logistics industry and regional economy. In this paper, the PSO-RBFNN model, a radial basis function neural network (RBFNN) combined with particle swarm optimization (PSO) algorithm, is studied. The PSO-RBFNN model is trained by indicators data in a region to predict the regional logistics demand. And the corresponding results indicate the model’s applicability and potential advantages. Zhineng Hu, Yixin Zhang, and Liming Yao Copyright © 2014 Zhineng Hu et al. All rights reserved. Adaptive Synchronization between Fractional-Order Chaotic Real and Complex Systems with Unknown Parameters Wed, 26 Nov 2014 11:46:01 +0000 http://www.hindawi.com/journals/ddns/2014/484039/ The complex modified projective synchronization (CMPS) between fractional-order chaotic real and complex systems is investigated for the first time. The parameters of both master and slave systems are assumed to be unknown in advance; moreover, the slave system is perturbed by unknown but bounded external disturbances. The master and slave systems that achieved CMPS can be synchronized up to a complex constant matrix. On the basis of frequency distributed model of fractional integrator and Lyapunov stability theory, a robust adaptive control law is designed to realize the CMPS for two different types of fractional-order chaotic systems. Meanwhile, to deal with these unknown parameters, some fractional-order type parametric update laws are provided. An example is given to demonstrate the effectiveness and feasibility of the proposed synchronization scheme. Xiaomin Tian Copyright © 2014 Xiaomin Tian. All rights reserved. A Novel Method for Decoding Any High-Order Hidden Markov Model Sun, 23 Nov 2014 09:13:06 +0000 http://www.hindawi.com/journals/ddns/2014/231704/ This paper proposes a novel method for decoding any high-order hidden Markov model. First, the high-order hidden Markov model is transformed into an equivalent first-order hidden Markov model by Hadar’s transformation. Next, the optimal state sequence of the equivalent first-order hidden Markov model is recognized by the existing Viterbi algorithm of the first-order hidden Markov model. Finally, the optimal state sequence of the high-order hidden Markov model is inferred from the optimal state sequence of the equivalent first-order hidden Markov model. This method provides a unified algorithm framework for decoding hidden Markov models including the first-order hidden Markov model and any high-order hidden Markov model. Fei Ye and Yifei Wang Copyright © 2014 Fei Ye and Yifei Wang. All rights reserved. A Scatter Search Approach for Multiobjective Selective Disassembly Sequence Problem Tue, 18 Nov 2014 09:31:44 +0000 http://www.hindawi.com/journals/ddns/2014/756891/ Disassembly sequence has received much attention in recent years. This work proposes a multiobjective optimization of model for selective disassembly sequences and maximizing disassembly profit and minimizing disassembly time. An improved scatter search (ISS) is adapted to solve proposed multiobjective optimization model, which embodies diversification generation of initial solutions, crossover combination operator, the local search strategy to improve the quality of new solutions, and reference set update method. To analyze the effect on the performance of ISS, simulation experiments are conducted on different products. The validity of ISS is verified by comparing the optimization effects of ISS and nondominated sorting genetic algorithm (NSGA-II). Xiwang Guo and Shixin Liu Copyright © 2014 Xiwang Guo and Shixin Liu. All rights reserved. Dynamic Traffic Network Model and Time-Dependent Braess’ Paradox Mon, 17 Nov 2014 12:26:48 +0000 http://www.hindawi.com/journals/ddns/2014/802129/ We propose a dynamic traffic network model and give the equilibrium condition and the equivalent variational inequality of the network. In this model, instead of the influence of inflow rate and output rate on the link congestion, the influence of the adjacent links at the same paths is considered; in this case, the equivalence between the equilibrium condition and the variational inequality is proved. Then we take an example about the paradox using the variational inequality and find that the probability and the severity that Braess’ paradox occurs change with the influence of other links changing. Subsequently, we discuss the influence of other links on whether the adding link works under the dynamic system optimal. At last, we give the relationship between the total congestion under dynamic user equilibrium and that under dynamic system optimal. The results imply that we should take some methods and adjust the interaction between links rationally with the dynamic change of traffic situations. Chunxue Zhao Copyright © 2014 Chunxue Zhao. All rights reserved. Codynamics of Four Variables Involved in Dengue Transmission and Its Control by Community Intervention: A System of Four Difference Equations Mon, 17 Nov 2014 11:31:49 +0000 http://www.hindawi.com/journals/ddns/2014/101965/ In the case of Dengue transmission and control, the interaction of nature and society is captured by a system of difference equations. For the purpose of studying the dynamics of these interactions, four variables involved in a Dengue epidemic, proportion of infected people (), number of mosquitoes involved in transmission (), mosquito habitats (), and population awareness (), are linked in a system of difference equations: , , , and , . The constraints have socioecological meaning. The initial conditions are such that , the parameters , and the parameters ,  ,  , and are positive. The paper is concerned with the analysis of solutions of the above system for . We studied the global asymptotic stability of the degenerate equilibrium. We also propose extensions of the above model and some open problems. We explored the role of memory in community awareness by numerical simulations. When the memory parameter is large, the proportion of infected people decreases and stabilizes at zero. Below a critical point we observe periodic oscillations. T. Awerbuch-Friedlander, Richard Levins, and M. Predescu Copyright © 2014 T. Awerbuch-Friedlander et al. All rights reserved. The Bifurcation and Control of a Single-Species Fish Population Logistic Model with the Invasion of Alien Species Sun, 16 Nov 2014 12:45:20 +0000 http://www.hindawi.com/journals/ddns/2014/548384/ The objective of this paper is to study systematically the bifurcation and control of a single-species fish population logistic model with the invasion of alien species based on the theory of singular system and bifurcation. It regards Spartina anglica as an invasive species, which invades the fisheries and aquaculture. Firstly, the stabilities of equilibria in this model are discussed. Moreover, the sufficient conditions for existence of the trans-critical bifurcation and the singularity induced bifurcation are obtained. Secondly, the state feedback controller is designed to eliminate the unexpected singularity induced bifurcation by combining harvested effort with the purification capacity. It obviously inhibits the switch of population and makes the system stable. Finally, the numerical simulation is proposed to show the practical significance of the bifurcation and control from the biological point of view. Yi Zhang, Qiaoling Zhang, Jinghao Li, and Qingling Zhang Copyright © 2014 Yi Zhang et al. All rights reserved. Stability of a Class of Fractional-Order Nonlinear Systems Sun, 16 Nov 2014 06:15:50 +0000 http://www.hindawi.com/journals/ddns/2014/724270/ In this letter stability analysis of fractional order nonlinear systems is studied. Some new sufficient conditions on the local (globally) asymptotic stability for a class of fractional order nonlinear systems with order are proposed by using properties of Mittag-Leffler function and the Gronwall inequality. And the corresponding stabilization criteria are also given. The numerical simulations of two systems with order and two systems with order illustrate the effectiveness and universality of the proposed approach. Tianzeng Li and Yu Wang Copyright © 2014 Tianzeng Li and Yu Wang. All rights reserved. Powertrain Matching and Optimization of Dual-Motor Hybrid Driving System for Electric Vehicle Based on Quantum Genetic Intelligent Algorithm Thu, 13 Nov 2014 14:36:04 +0000 http://www.hindawi.com/journals/ddns/2014/956521/ In order to increase the driving range and improve the overall performance of all-electric vehicles, a new dual-motor hybrid driving system with two power sources was proposed. This system achieved torque-speed coupling between the two power sources and greatly improved the high performance working range of the motors; at the same time, continuously variable transmission (CVT) was achieved to efficiently increase the driving range. The power system parameters were determined using the “global optimization method”; thus, the vehicle’s dynamics and economy were used as the optimization indexes. Based on preliminary matches, quantum genetic algorithm was introduced to optimize the matching in the dual-motor hybrid power system. Backward simulation was performed on the combined simulation platform of Matlab/Simulink and AVL-Cruise to optimize, simulate, and verify the system parameters of the transmission system. Results showed that quantum genetic algorithms exhibited good global optimization capability and convergence in dealing with multiobjective and multiparameter optimization. The dual-motor hybrid-driving system for electric cars satisfied the dynamic performance and economy requirements of design, efficiently increasing the driving range of the car, having high performance, and reducing energy consumption of 15.6% compared with the conventional electric vehicle with single-speed reducers. Yong Wang and Dongye Sun Copyright © 2014 Yong Wang and Dongye Sun. All rights reserved. Levenberg-Marquardt Algorithm for Mackey-Glass Chaotic Time Series Prediction Tue, 11 Nov 2014 07:57:34 +0000 http://www.hindawi.com/journals/ddns/2014/193758/ For decades, Mackey-Glass chaotic time series prediction has attracted more and more attention. When the multilayer perceptron is used to predict the Mackey-Glass chaotic time series, what we should do is to minimize the loss function. As is well known, the convergence speed of the loss function is rapid in the beginning of the learning process, while the convergence speed is very slow when the parameter is near to the minimum point. In order to overcome these problems, we introduce the Levenberg-Marquardt algorithm (LMA). Firstly, a rough introduction is given to the multilayer perceptron, including the structure and the model approximation method. Secondly, we introduce the LMA and discuss how to implement the LMA. Lastly, an illustrative example is carried out to show the prediction efficiency of the LMA. Simulations show that the LMA can give more accurate prediction than the gradient descent method. Junsheng Zhao, Yongmin Li, Xingjiang Yu, and Xingfang Zhang Copyright © 2014 Junsheng Zhao et al. All rights reserved. A Case-Based Reasoning Method for Remanufacturing Process Planning Tue, 11 Nov 2014 06:30:26 +0000 http://www.hindawi.com/journals/ddns/2014/168631/ Remanufacturing is a practice of growing importance due to its increasing environmental and economic benefits. Process planning plays a critical role in realizing a successful remanufacturing strategy. This paper presents a case-based reasoning method for remanufacturing process planning, which allows a process planner to rapidly retrieve, reuse, revise, and retain the solutions to past process problems. In the proposed method, influence factors including essential characteristics, failure characteristics, and remanufacturing processing characteristics are identified, and the local similarity of influence factors between the new case and the past cases is determined by nearest neighbor matching method, and then the vector of correction factor for local similarity is utilized in the nearest neighbor algorithm to improve the accuracy and effectiveness of case searching. To assess the usefulness and practicality of the proposed method, an illustrative example is given and the results are discussed. Fan Zhou, Zhigang Jiang, Hua Zhang, and Yan Wang Copyright © 2014 Fan Zhou et al. All rights reserved. Discrete Dynamic Gaming Models in Supply Chain Management and Project Management Mon, 10 Nov 2014 00:00:00 +0000 http://www.hindawi.com/journals/ddns/2014/960239/ Jun Zhuang, Xiaolin Xu, and Gangshu (George) Cai Copyright © 2014 Jun Zhuang et al. All rights reserved. Unsupervised SAR Image Segmentation Based on a Hierarchical TMF Model in the Discrete Wavelet Domain for Sea Area Detection Tue, 04 Nov 2014 08:59:32 +0000 http://www.hindawi.com/journals/ddns/2014/354704/ Unsupervised synthetic aperture radar (SAR) image segmentation is a fundamental preliminary processing step required for sea area detection in military applications. The purpose of this step is to classify large image areas into different segments to assist with identification of the sea area and the ship target within the image. The recently proposed triplet Markov field (TMF) model has been successfully used for segmentation of nonstationary SAR images. This letter presents a hierarchical TMF model in the discrete wavelet domain of unsupervised SAR image segmentation for sea area detection, which we have named the wavelet hierarchical TMF (WHTMF) model. The WHTMF model can precisely capture the global and local image characteristics in the two-pass computation of posterior distribution. The multiscale likelihood and the multiscale energy function are constructed to capture the intrascale and intrascale dependencies in a random field (). To model the SAR data related to radar backscattering sources, the Gaussian distribution is utilized. The effectiveness of the proposed model for SAR image segmentation is evaluated using synthesized and real SAR data. Jiajing Wang, Shuhong Jiao, Lianyang Shen, Zhenyu Sun, and Lin Tang Copyright © 2014 Jiajing Wang et al. All rights reserved. Movement Control in Recovering UUV Based on Two-Stage Discrete T-S Fuzzy Model Tue, 04 Nov 2014 08:00:42 +0000 http://www.hindawi.com/journals/ddns/2014/362787/ A two-stage discrete T-S fuzzy model controller, which is formed by a motion controller and a dynamic controller connected in series, is presented to solve UUV (unmanned underwater vehicle) movement control problem for recovering. The motion controller is designed based on the uncertain T-S model and the concept of discrete fuzzy vector. The position error between UUV and moving platform as the input of the motion controller is converted into the speed commands of UUV at the next time. The dynamic controller design is based on the theory of fuzzy region model and a relaxed condition for Lyapunov stabilization function is derived in the form of linear matrix inequalities, which generate force and torque required to complete the recovery task. The feasibility and the efficiency of the proposed control scheme are illustrated through the simulations that UUV follows moving platform. Zheping Yan, Bing Hao, Yibo Liu, and Shuping Hou Copyright © 2014 Zheping Yan et al. All rights reserved. A Dufort-Frankel Difference Scheme for Two-Dimensional Sine-Gordon Equation Wed, 29 Oct 2014 09:08:21 +0000 http://www.hindawi.com/journals/ddns/2014/784387/ A standard Crank-Nicolson finite-difference scheme and a Dufort-Frankel finite-difference scheme are introduced to solve two-dimensional damped and undamped sine-Gordon equations. The stability and convergence of the numerical methods are considered. To avoid solving the nonlinear system, the predictor-corrector techniques are applied in the numerical methods. Numerical examples are given to show that the numerical results are consistent with the theoretical results. Zongqi Liang, Yubin Yan, and Guorong Cai Copyright © 2014 Zongqi Liang et al. All rights reserved. Sampled-Data Consensus for High-Order Multiagent Systems under Fixed and Randomly Switching Topology Wed, 22 Oct 2014 11:26:58 +0000 http://www.hindawi.com/journals/ddns/2014/598965/ This paper studies the sampled-data based consensus of multiagent system with general linear time-invariant dynamics. It focuses on looking for a maximum allowable sampling period bound such that as long as the sampling period is less than this bound, there always exist linear consensus protocols solving the consensus problem. Both fixed and randomly switching topologies are considered. For systems under fixed topology, a necessary and sufficient sampling period bound is obtained for single-input multiagent systems, and a sufficient allowable bound is proposed for multi-input systems by solving the optimal control problem of certain system with uncertainty. For systems under randomly switching topologies, tree-type and complete broadcasting network with Bernoulli packet losses are discussed, and explicit allowable sampling period bounds are, respectively, given based on the unstable eigenvalues of agent’s system matrix and packet loss probability. Numerical examples are given to illustrate the results. Niu Jie and Li Zhong Copyright © 2014 Niu Jie and Li Zhong. All rights reserved. A Constrained Algorithm Based NMFα for Image Representation Wed, 22 Oct 2014 07:57:08 +0000 http://www.hindawi.com/journals/ddns/2014/179129/ Nonnegative matrix factorization (NMF) is a useful tool in learning a basic representation of image data. However, its performance and applicability in real scenarios are limited because of the lack of image information. In this paper, we propose a constrained matrix decomposition algorithm for image representation which contains parameters associated with the characteristics of image data sets. Particularly, we impose label information as additional hard constraints to the α-divergence-NMF unsupervised learning algorithm. The resulted algorithm is derived by using Karush-Kuhn-Tucker (KKT) conditions as well as the projected gradient and its monotonic local convergence is proved by using auxiliary functions. In addition, we provide a method to select the parameters to our semisupervised matrix decomposition algorithm in the experiment. Compared with the state-of-the-art approaches, our method with the parameters has the best classification accuracy on three image data sets. Chenxue Yang, Tao Li, Mao Ye, Zijian Liu, and Jiao Bao Copyright © 2014 Chenxue Yang et al. All rights reserved. Uniform Attractor for the Fractional Nonautonomous Long-Short Wave Equations Mon, 20 Oct 2014 00:00:00 +0000 http://www.hindawi.com/journals/ddns/2014/712183/ We firstly proved the existence and the uniqueness of the solution for the -periodic fractional nonautonomous long-short wave equations with translation compact force by using Galerkin method and then obtained the compact uniform attractor of the system. Huanmin Ge and Jie Xin Copyright © 2014 Huanmin Ge and Jie Xin. All rights reserved. An Allometric Algorithm for Fractal-Based Cobb-Douglas Function of Geographical Systems Mon, 20 Oct 2014 00:00:00 +0000 http://www.hindawi.com/journals/ddns/2014/910457/ The generalized Cobb-Douglas production function has been derived from a general input-output relation based on fractality assumptions. It was proved to be a useful self-affine model for geographical analysis. However, the ordinary least square calculation is always an ineffectual method for the Cobb-Douglas modeling because of the multicollinearity in the logarithmic linear regression. In this paper, a novel approach is proposed to build the geographical Cobb-Douglas models. Combining the concept of allometric scaling with the linear regression technique, we obtain a simple algorithm that can be employed to estimate the parameters of the Cobb-Douglas function. As a case, the algorithm and models are applied to the public transportation of China’s cities, and the results validate the allometric algorithm. A conclusion can be drawn that the allometric analysis is an effective way of modeling geographical systems with the general Cobb-Douglas function. This study is significant for integrating the notions of allometry, fractals, and scaling into a new framework to form a quantitative methodology of spatial analysis. Hongyu Luo and Yanguang Chen Copyright © 2014 Hongyu Luo and Yanguang Chen. All rights reserved. Damping Coefficient Induces Stochastic Multiresonance in Bistable System with Asymmetric Dichotomous Noise Sun, 19 Oct 2014 00:00:00 +0000 http://www.hindawi.com/journals/ddns/2014/850361/ Stochastic resonance (SR) and stochastic multiresonance (SMR) phenomena as a function of the underdamping and overdamping coefficients in bistable system with asymmetric dichotomous noise are investigated numerically. By the efficient numerical simulation of the asymmetric dichotomous noise and the fourth-order Runge-Kutta algorithm, we calculate the system responses, the averaged power spectrum, and the signal-noise-ratio (SNR) that can be a measure of the existence of SR and SMR phenomenon. And the effects of damping coefficients on the three characteristics are analyzed. Firstly, it is found that the periodic asymmetric distribution of the particle’s hopping between two potential wells in the system response is gradually weakened as underdamping coefficient is increased to overdamping coefficient. And it also displays the periodic asymmetric distribution under the circumstance of overdamping coefficient. Then the averaged power spectrum exhibits multiple sharp peaks, and the highest peak increases and decreases for underdamping coefficient which is added to overdamping coefficient. Finally, SNR versus the damping coefficient for the system parameters and the noise parameters are acquired and they show multiple peaks and valleys, which illustrates the obvious SMR phenomena in bistable system with asymmetric dichotomous noise. Juan Wu and Yong Xu Copyright © 2014 Juan Wu and Yong Xu. All rights reserved. On a -Analogue of the Elzaki Transform Called Mangontarum -Transform Mon, 13 Oct 2014 08:41:59 +0000 http://www.hindawi.com/journals/ddns/2014/825618/ Two -analogues of the Elzaki transform, called Mangontarum -transforms, are introduced in this paper. Properties such as the transforms of -trigonometric functions, transform of -derivatives, duality relation, convolution identity, -derivative of transforms, and transform of the Heaviside function are derived and presented. Moreover, we will consider applications of the Mangontarum -transform of the first kind to some ordinary -differential equations with initial values. Mahid M. Mangontarum Copyright © 2014 Mahid M. Mangontarum. All rights reserved. Extremal Solutions to Periodic Boundary Value Problem of Nabla Integrodifferential Equation of Volterra Type on Time Scales Mon, 13 Oct 2014 00:00:00 +0000 http://www.hindawi.com/journals/ddns/2014/205659/ We firstly establish some new theorems on time scales, and then, by employing them together with a new comparison result and the monotone iterative technique, we show the existence of extremal solutions to the following nabla integrodifferential periodic boundary value problem: ,  , where is a time scale. Yunlong Shi and Junfang Zhao Copyright © 2014 Yunlong Shi and Junfang Zhao. All rights reserved. Correlation and Spectral Properties of a Coupled Nonlinear Dynamical System in the Context of Numerical Weather Prediction and Climate Modeling Sun, 12 Oct 2014 12:17:55 +0000 http://www.hindawi.com/journals/ddns/2014/498184/ Complex dynamical processes occurring in the earth’s climate system are strongly nonlinear and exhibit wave-like oscillations within broad time-space spectrum. One way to imitate essential features of such processes is using a coupled nonlinear dynamical system, obtained by coupling two versions of the well-known Lorenz (1963) model with distinct time scales that differ by a certain time-scale factor. This dynamical system is frequently applied for studying various aspects of atmospheric and climate dynamics, as well as for estimating the effectiveness of numerical algorithms and techniques used in numerical weather prediction, data assimilation, and climate simulation. This paper examines basic dynamic, correlative, and spectral properties of this system and quantifies the influence of the coupling strength on power spectrum densities, spectrograms, and autocorrelation functions. Sergei Soldatenko and Denis Chichkine Copyright © 2014 Sergei Soldatenko and Denis Chichkine. All rights reserved. Behavior of an Exponential System of Difference Equations Mon, 15 Sep 2014 11:45:30 +0000 http://www.hindawi.com/journals/ddns/2014/607281/ We study the qualitative behavior of the following exponential system of rational difference equations:  = /,   = /,   =  where , , , , , and and initial conditions , , , and are positive real numbers. More precisely, we investigate the boundedness character and persistence, existence and uniqueness of positive equilibrium, local and global behavior, and rate of convergence of positive solutions that converges to unique positive equilibrium point of the system. Some numerical examples are given to verify our theoretical results. A. Q. Khan and M. N. Qureshi Copyright © 2014 A. Q. Khan and M. N. Qureshi. All rights reserved. Modified Differential Transform Method for Solving the Model of Pollution for a System of Lakes Mon, 15 Sep 2014 00:00:00 +0000 http://www.hindawi.com/journals/ddns/2014/645726/ This work presents the application of the differential transform method (DTM) to the model of pollution for a system of three lakes interconnected by channels. Three input models (periodic, exponentially decaying, and linear) are solved to show that DTM can provide analytical solutions of pollution model in convergent series form. In addition, we present the posttreatment of the power series solutions with the Laplace-Padé resummation method as a useful strategy to extend the domain of convergence of the approximate solutions. The Fehlberg fourth-fifth order Runge-Kutta method with degree four interpolant (RKF45) numerical solution of the lakes system problem is used as a reference to compare with the analytical approximations showing the high accuracy of the results. The main advantage of the proposed technique is that it is based on a few straightforward steps and does not generate secular terms or depend of a perturbation parameter. Brahim Benhammouda, Hector Vazquez-Leal, and Luis Hernandez-Martinez Copyright © 2014 Brahim Benhammouda et al. All rights reserved. Left-Turning Vehicle Trajectory Modeling and Guide Line Setting at the Intersection Wed, 03 Sep 2014 09:16:25 +0000 http://www.hindawi.com/journals/ddns/2014/950219/ When left-turning vehicles are released from the multiple left-turning lanes at the signalized intersection, there will be conflicts among them, and the conflicts will affect the traffic operation and safety. In order to solve the problem, by extracting running trajectories of left-turning vehicles and analyzing distribution characteristics of trajectories, velocity changing characteristics, and flow changing characteristics, the left-turning vehicle’s trajectory model was established. On the basis of the above research, taking an example of quadruple left-turning lanes, the idea of setting left-turning guide line at the intersection was proposed. Through instance verification, we could get the conclusion that the method of using left-turning guide line to control vehicles’ turning process can effectively reduce traffic conflicts and delay and improve traffic efficiency. Fulu Wei, Weiwei Guo, Xin Liu, Chunyan Liang, and Tianjun Feng Copyright © 2014 Fulu Wei et al. All rights reserved. Torque Split Strategy for Parallel Hybrid Electric Vehicles with an Integrated Starter Generator Wed, 03 Sep 2014 07:25:43 +0000 http://www.hindawi.com/journals/ddns/2014/793864/ This paper presents a torque split strategy for parallel hybrid electric vehicles with an integrated starter generator (ISG-PHEV) by using fuzzy logic control. By combining the efficiency map and the optimum torque curve of the internal combustion engine (ICE) with the state of charge (SOC) of the batteries, the torque split strategy is designed, which manages the ICE within its peak efficiency region. Taking the quantified ICE torque, the quantified SOC of the batteries, and the quantified ICE speed as inputs, and regarding the output torque demanded on the ICE as an output, a fuzzy logic controller (FLC) with relevant fuzzy rules has been developed to determine the optimal torque distribution among the ICE, the ISG, and the electric motor/generator (EMG) effectively. The simulation results reveal that, compared with the conventional torque control strategy which uses rule-based controller (RBC) in different driving cycles, the proposed FLC improves the fuel economy of the ISG-PHEV, increases the efficiency of the ICE, and maintains batteries SOC within its operation range more availably. Zhumu Fu, Aiyun Gao, Xiaohong Wang, and Xiaona Song Copyright © 2014 Zhumu Fu et al. All rights reserved.