Journal of Applied Mathematics The latest articles from Hindawi Publishing Corporation © 2015 , Hindawi Publishing Corporation . All rights reserved. Performance Prediction Modelling for Flexible Pavement on Low Volume Roads Using Multiple Linear Regression Analysis Wed, 29 Jul 2015 06:39:32 +0000 Prediction models for low volume village roads in India are developed to evaluate the progression of different types of distress such as roughness, cracking, and potholes. Even though the Government of India is investing huge quantum of money on road construction every year, poor control over the quality of road construction and its subsequent maintenance is leading to the faster road deterioration. In this regard, it is essential that scientific maintenance procedures are to be evolved on the basis of performance of low volume flexible pavements. Considering the above, an attempt has been made in this research endeavor to develop prediction models to understand the progression of roughness, cracking, and potholes in flexible pavements exposed to least or nil routine maintenance. Distress data were collected from the low volume rural roads covering about 173 stretches spread across Tamil Nadu state in India. Based on the above collected data, distress prediction models have been developed using multiple linear regression analysis. Further, the models have been validated using independent field data. It can be concluded that the models developed in this study can serve as useful tools for the practicing engineers maintaining flexible pavements on low volume roads. C. Makendran, R. Murugasan, and S. Velmurugan Copyright © 2015 C. Makendran et al. All rights reserved. Asymptotic Formulas for the Reflection/Transmission of Long Water Waves Propagating in a Tapered and Slender Harbor Mon, 27 Jul 2015 13:43:23 +0000 We obtain asymptotic formulas for the reflection/transmission coefficients of linear long water waves, propagating in a harbor composed of a tapered and slender region connected to uniform inlet and outlet regions. The region with variable character obeys a power-law. The governing equations are presented in dimensionless form. The reflection/transmission coefficients are obtained for the limit of the parameter , which corresponds to a wavelength shorter than the characteristic horizontal length of the harbor. The asymptotic formulas consider those cases when the geometry of the harbor can be variable in width and depth: linear or parabolic among other transitions or a combination of these geometries. For harbors with nonlinear transitions, the parabolic geometry is less reflective than the other cases. The reflection coefficient for linear transitions just presents an oscillatory behavior. We can infer that the deducted formulas provide as first approximation a practical reference to the analysis of wave reflection/transmission in harbors. Eric-Gustavo Bautista, Federico Méndez, and Oscar Bautista Copyright © 2015 Eric-Gustavo Bautista et al. All rights reserved. A Smoothening Method for the Piecewise Linear Interpolation Mon, 27 Jul 2015 06:19:14 +0000 We propose a method to smoothen a piecewise linear interpolation at a small number of nodes on a bounded interval. The method employs a sigmoidal type weight function having a property that clusters most points on the left side of the interval toward 0 and those on the right side toward 1. The proposed method results in a noninterpolatory approximation which is smooth over the whole interval. We provide an algorithm for implementing the presented smoothening method. To demonstrate usefulness of the presented method we introduce some numerical examples and investigate the results. Beong In Yun Copyright © 2015 Beong In Yun. All rights reserved. On a Nonlocal Damping Model in Ferromagnetism Wed, 15 Jul 2015 14:41:42 +0000 We consider a mathematical model describing nonlocal damping in magnetization dynamics. The model consists of a modified form of the Landau-Lifshitz-Gilbert (LLG) equation for the evolution of the magnetization vector in a rigid ferromagnet. We give a global existence result and characterize the long time behaviour of the obtained solutions. The sensitivity of the model with respect to large and small nonlocal damping parameters is also discussed. M. Moumni and M. Tilioua Copyright © 2015 M. Moumni and M. Tilioua. All rights reserved. Adding Education to “Test and Treat”: Can We Overcome Drug Resistance? Sun, 12 Jul 2015 13:08:23 +0000 Recent mathematical modelling has advocated for rapid “test-and-treat” programs for HIV in the developing world, where HIV-positive individuals are identified and immediately begin a course of antiretroviral treatment, regardless of the length of time they have been infected. However, the foundations of this modelling ignored the effects of drug resistance on the epidemic. It also disregarded the heterogeneity of behaviour changes that may occur, as a result of education that some individuals may receive upon testing and treatment. We formulate an HIV/AIDS model to theoretically investigate how testing, educating HIV-positive cases, treatment, and drug resistance affect the HIV epidemic. We consider a variety of circumstances: both when education is included and not included, when testing and treatment are linked or are separate, when education is only partly effective, and when treatment leads to drug resistance. We show that education, if it is properly harnessed, can be a force strong enough to overcome the effects of antiretroviral drug resistance; however, in the absence of education, “test and treat” is likely to make the epidemic worse. Mo’tassem Al-arydah and Robert Smith? Copyright © 2015 Mo’tassem Al-arydah and Robert Smith?. All rights reserved. A Crank-Nicolson Scheme for the Dirichlet-to-Neumann Semigroup Thu, 09 Jul 2015 14:28:26 +0000 The aim of this work is to study a semidiscrete Crank-Nicolson type scheme in order to approximate numerically the Dirichlet-to-Neumann semigroup. We construct an approximating family of operators for the Dirichlet-to-Neumann semigroup, which satisfies the assumptions of Chernoff’s product formula, and consequently the Crank-Nicolson scheme converges to the exact solution. Finally, we write a finite element scheme for the problem, and we illustrate this convergence by means of a FreeFem++ implementation. Rola Ali Ahmad, Toufic El Arwadi, Houssam Chrayteh, and Jean-Marc Sac-Epée Copyright © 2015 Rola Ali Ahmad et al. All rights reserved. Optimal Intervention Strategies for the Spread of Obesity Tue, 07 Jul 2015 09:45:32 +0000 The present study considers a deterministic compartmental model for obesity dynamics. The model exhibits forward bifurcation at basic reproduction number, , that is; for , obesity is not sustained. However for the model approaches a locally asymptotically stable endemic equilibrium. To control this epidemic and reduce the obesity at the endemic equilibrium, we considered intervention strategies for the spread of overweight and obesity, where Pontryagin’s Maximum Principle is applied. The numerical technique was used to show that there are effective control strategies that include minimizing the social contact rate with the overweight and obese population and campaigning. Numerical results indicated the effects of the two controls (prevention and education/campaigning) to be different. In societies with lower obesity, the social contact rate with the overweight and obese population plays a more prominent role in spreading obesity than lack of educational programs/campaigns. However, for societies with very high obesity burden, education/campaigning proved to be highly effective strategies. Reducing the social contact rate can result in other results such as a depression and an invasion of their individual rights. The appropriate approach to obesity is needed to lower obese societies. Chunyoung Oh and Masud M A Copyright © 2015 Chunyoung Oh and Masud M A. All rights reserved. The Role of Optimal Intervention Strategies on Controlling Excessive Alcohol Drinking and Its Adverse Health Effects Sun, 05 Jul 2015 12:37:25 +0000 We propose and analyze a mathematical model for alcohol drinking problem. The transmission process is modeled as a social “contact” process between “heavy” alcohol drinkers and “light” alcohol drinkers within an unchanging shared drinking environment. The basic reproductive number of the model is computed and the stability of the model steady states is investigated. Further, the model is fitted to data on alcohol drinking for Cape Town and Gauteng, South Africa. In addition, the basic model is extended to incorporate three time dependent intervention strategies. The control functions represent the efforts and policies aimed at weakening the intensity of social interactions between light and heavy drinkers and increase the fraction of treated individuals who permanently quit alcohol drinking. Optimal control results suggest that effective control of high-risk alcohol drinking can be achieved if more resources and efforts are devoted on weakening the intensity of social interactions between light and heavy drinkers. Steady Mushayabasa Copyright © 2015 Steady Mushayabasa. All rights reserved. Analysis and Design of Robust Positivity and Stability for Continuous-Time Linear Uncertain Systems Sun, 05 Jul 2015 08:35:42 +0000 This paper deals with the analysis and design of positivity and stability of linear continuous conic systems. First, two robustness analysis theorems are proposed for the systems with state-feedback. Second, the state-feedback stabilization problem is solved by using linear programming (LP). Numerical examples are given for illustration. Finally, the conclusions are made. Kuo-Liang Yen, Kuo-Shong Wang, and Yau-Tarng Juang Copyright © 2015 Kuo-Liang Yen et al. All rights reserved. Multisorted Tree-Algebras for Hierarchical Resources Allocation Mon, 29 Jun 2015 08:46:11 +0000 This paper presents a generic abstract model for the study of disparities between goals and results in hierarchical multiresources allocation systems. In an organization, disparities in resource allocation may occur, when, after comparison of a resource allocation decision with an allocation reference goal or property, some agents have surplus resources to accomplish their tasks, while at the same time other agents have deficits of expected resources. In the real world, these situations are frequently encountered in organizations facing scarcity of resources and/or inefficient management. These disparities can be corrected using allocation decisions, by measuring and reducing gradually such disparities and their related costs, without totally canceling the existing resource distribution. While a lot of research has been carried out in the area of resource allocation, this specific class of problems has not yet been formally studied. The paper exposes the results of an exploratory research study of this class of problems. It identifies the commonalities of the family of hierarchical multiresource allocation systems and proposes the concept of multisorted tree-algebra for the modeling of these problems. The research presented here is not yet an in-depth descriptive research study of the mathematical theory of multisorted tree-algebra, but a formal study on modelling hierarchical multiresource allocation problems. Erick Patrick Zobo and Marcel Fouda Ndjodo Copyright © 2015 Erick Patrick Zobo and Marcel Fouda Ndjodo. All rights reserved. Shape Preserving Data Interpolation Using Rational Cubic Ball Functions Wed, 24 Jun 2015 06:19:36 +0000 A smooth curve interpolation scheme for positive, monotone, and convex data is developed. This scheme uses rational cubic Ball representation with four shape parameters in its description. Conditions of two shape parameters are derived in such a way that they preserve the shape of the data, whereas the other two parameters remain free to enable the user to modify the shape of the curve. The degree of smoothness is . The outputs from a number of numerical experiments are presented. Ayser Nasir Hassan Tahat, Abd Rahni Mt Piah, and Zainor Ridzuan Yahya Copyright © 2015 Ayser Nasir Hassan Tahat et al. All rights reserved. Preconditioning Filter Bank Decomposition Using Structured Normalized Tight Frames Mon, 22 Jun 2015 08:32:11 +0000 We turn a given filter bank into a filtering scheme that provides perfect reconstruction, synthesis is the adjoint of the analysis part (so-called unitary filter banks), all filters have equal norm, and the essential features of the original filter bank are preserved. Unitary filter banks providing perfect reconstruction are induced by tight generalized frames, which enable signal decomposition using a set of linear operators. If, in addition, frame elements have equal norm, then the signal energy is spread through the various filter bank channels in some uniform fashion, which is often more suitable for further signal processing. We start with a given generalized frame whose elements allow for fast matrix vector multiplication, as, for instance, convolution operators, and compute a normalized tight frame, for which signal analysis and synthesis still preserve those fast algorithmic schemes. Martin Ehler Copyright © 2015 Martin Ehler. All rights reserved. Method of Integral Equations for the Problem of Electrical Tomography in a Medium with Ground Surface Relief Tue, 16 Jun 2015 07:14:24 +0000 The direct task of the subsurface exploration of a homogeneous medium with surface relief by the resistivity method is analyzed. To calculate the resistivity field for such a medium, the method of integral equations was successfully applied for the first time. The corresponding integral equation for the density of secondary current sources on the surface of the medium was established. The method of computational grid construction, adapted to the characteristics of the surface relief, was developed for the numerical solution of the integral equation. This method enables the calculation of the resistivity field of a point source on a surface that is not smooth and allows for steep ledges. Numerical examples of the calculation of resistivity fields and apparent resistivity are shown. The anomalies of apparent resistivity arising from the deviation of the surface shape from a flat medium were quantitatively established as model examples. Calculations of apparent resistivity for the direct current sounding method were carried out using modifications of the electrical tomography approach. Tolkyn Mirgalikyzy, Balgaisha Mukanova, and Igor Modin Copyright © 2015 Tolkyn Mirgalikyzy et al. All rights reserved. Function Synthesis Algorithm of RTD-Based Universal Threshold Logic Gate Thu, 11 Jun 2015 09:22:02 +0000 The resonant tunneling device (RTD) has attracted much attention because of its unique negative differential resistance characteristic and its functional versatility and is more suitable for implementing the threshold logic gate. The universal logic gate has become an important unit circuit of digital circuit design because of its powerful logic function, while the threshold logic gate is a suitable unit to design the universal logic gate, but the function synthesis algorithm for the -variable logical function implemented by the RTD-based universal logic gate (UTLG) is relatively deficient. In this paper, three-variable threshold functions are divided into four categories; based on the Reed-Muller expansion, two categories of these are analyzed, and a new decomposition algorithm of the three-variable nonthreshold functions is proposed. The proposed algorithm is simple and the decomposition results can be obtained by looking up the decomposition table. Then, based on the Reed-Muller algebraic system, the arbitrary -variable function can be decomposed into three-variable functions, and a function synthesis algorithm for the -variable logical function implemented by UTLG and XOR2 is proposed, which is a simple programmable implementation. Maoqun Yao, Kai Yang, Congyuan Xu, and Jizhong Shen Copyright © 2015 Maoqun Yao et al. All rights reserved. A Fuzzy Delay Approach for HIV Dynamics Using a Cellular Automaton Thu, 11 Jun 2015 07:38:43 +0000 The objective of this research is to study the evolution of CD4+ T lymphocytes infected with HIV in HIV-seropositive individuals under antiretroviral treatment utilizing a mathematical model consisting of a system of delay-differential equations. The infection rate of CD4+ T lymphocytes is a time-dependent parameter with delay. Such delay is given by a fuzzy number due to the uncertainty of the effects of both pharmacological and intracellular delays. A cellular automaton is utilized to estimate the parameters of the system. The effects of antiretroviral therapy in the cellular automaton are modeled using a fuzzy rule-based system with two inputs: the medication potency and the treatment adhesion for three hypothetical individuals. For each of them, we determine the infection rate of CD4+ T lymphocytes, which is different from zero, as opposed to other studies reported in the literature. As the infection rate is considered a fuzzy parameter, we determine the fuzzy and the defuzzified solutions for the infected CD4+ T lymphocytes. We obtain the maximum values of infected cells for individuals that receive low, medium, and high potency medication and treatment adhesion. The results obtained are in accordance qualitatively with what would be expected in a real situation. R. Motta Jafelice, C. A. F. Silva, L. C. Barros, and R. C. Bassanezi Copyright © 2015 R. Motta Jafelice et al. All rights reserved. Optimization of the Aedes aegypti Control Strategies for Integrated Vector Management Mon, 08 Jun 2015 13:52:40 +0000 We formulate an infinite-time quadratic functional minimization problem of Aedes aegypti mosquito population. Three techniques of mosquito population management, chemical insecticide control, sterile insect technique control, and environmental carrying capacity reduction, are combined in order to obtain the most sustainable strategy to reduce mosquito population and consequently dengue disease. The solution of the optimization control problem is based on the ideas of the Dynamic Programming and Lyapunov Stability using State-Dependent Riccati Equation (SDRE) control method. Different scenarios are analyzed combining three mentioned population management efforts in order to assess the most sustainable policy to reduce the mosquito population. Marat Rafikov, Elvira Rafikova, and Hyun Mo Yang Copyright © 2015 Marat Rafikov et al. All rights reserved. On -Vertex-Antimagic Edge Labeling of Regular Graphs Mon, 08 Jun 2015 13:29:28 +0000 An -vertex-antimagic edge labeling (or an -VAE labeling, for short) of is a bijective mapping from the edge set of a graph to the set of integers with the property that the vertex-weights form an arithmetic sequence starting from and having common difference , where and are two positive integers, and the vertex-weight is the sum of the labels of all edges incident to the vertex. A graph is called -antimagic if it admits an -VAE labeling. In this paper, we investigate the existence of -VAE labeling for disconnected 3-regular graphs. Also, we define and study a new concept -vertex-antimagic edge deficiency, as an extension of -VAE labeling, for measuring how close a graph is away from being an -antimagic graph. Furthermore, the -VAE deficiency of Hamiltonian regular graphs of even degree is completely determined. More open problems are mentioned in the concluding remarks. Martin Bača, Andrea Semaničová-Feňovčíková, Tao-Ming Wang, and Guang-Hui Zhang Copyright © 2015 Martin Bača et al. All rights reserved. A Family of Trigonometrically Fitted Enright Second Derivative Methods for Stiff and Oscillatory Initial Value Problems Mon, 08 Jun 2015 12:34:27 +0000 A family of Enright’s second derivative formulas with trigonometric basis functions is derived using multistep collocation method. The continuous schemes obtained are used to generate complementary methods. The stability properties of the methods are discussed. The methods which can be applied in predictor-corrector form are implemented in block form as simultaneous numerical integrators over nonoverlapping intervals. Numerical results obtained using the proposed block form reveal that the new methods are efficient and highly competitive with existing methods in the literature. F. F. Ngwane and S. N. Jator Copyright © 2015 F. F. Ngwane and S. N. Jator. All rights reserved. The Hadamard Product of a Nonsingular General H-Matrix and Its Inverse Transpose Is Diagonally Dominant Thu, 04 Jun 2015 07:23:28 +0000 We study the combined matrix of a nonsingular H-matrix. These matrices can belong to two different H-matrices classes: the most common, invertible class, and one particular class named mixed class. Different results regarding diagonal dominance of the inverse matrix and the combined matrix of a nonsingular H-matrix belonging to the referred classes are obtained. We conclude that the combined matrix of a nonsingular H-matrix is always diagonally dominant and then it is an H-matrix. In particular, the combined matrix in the invertible class remains in the same class. Rafael Bru, Maria T. Gassó, Isabel Giménez, and José A. Scott Copyright © 2015 Rafael Bru et al. All rights reserved. Corrigendum to “Solving Dynamic Traveling Salesman Problem Using Dynamic Gaussian Process Regression” Sun, 31 May 2015 14:25:18 +0000 Stephen M. Akandwanaho, Aderemi O. Adewumi, and Ayodele A. Adebiyi Copyright © 2015 Stephen M. Akandwanaho et al. All rights reserved. Perturbation and Truncation of Probability Generating Function Methods for Stiff Chemical Reactions Thu, 28 May 2015 11:40:28 +0000 One can reformulate chemical master equations of the stochastic reaction network into a partial differential equation (PDE) of a probability generating function (PGF). In this paper, we present two improvements in such PGF-PDE approach, based on perturbation and double-truncation, respectively. The stiff system that involves fast and slow reactions together often requires high computational cost. By applying the perturbation method to PGF-PDEs, we expand the equation in terms of a small reaction rate which is often responsible for such stiffness of the system. Also by doubly truncating, we dump relatively small terms and reduce the computational load significantly at each time step. The terms corresponding to rare events are sieved out through truncations of Taylor expansion. It is shown through numerical examples of enzyme kinetics, transition model, and Brusselator model that the suggested method is accurate and efficient for approximation of the state probabilities. Soyeong Jeong, Pilwon Kim, and Chang Hyeong Lee Copyright © 2015 Soyeong Jeong et al. All rights reserved. Synchronized Control for Five-Story Building under Earthquake Loads Thu, 07 May 2015 11:45:25 +0000 Synchronized control is implemented for a five-story building under earthquake loads and its capabilities are investigated for protection of building under earthquake. In this regard, we applied control algorithm in form of synchronized control for structural vibration reduction. Simulation results of modeling indicated that not only the provided control is able to reduce the responses of vibrations for the structure, but also it is even capable of supplying the objectives of synchronized control at the same time. Numerical results for uncontrolled, traditional control and synchronized control coupled with algorithm are presented. It is shown that for El Centro and Bam earthquakes the synchronized control is more efficient to reduce damage to the given structures. Javad Mesbahi and Alaeddin Malek Copyright © 2015 Javad Mesbahi and Alaeddin Malek. All rights reserved. Piecewise Model and Parameter Obtainment of Governor Actuator in Turbine Tue, 05 May 2015 06:06:50 +0000 The governor actuators in some heat-engine plants have nonlinear valves. This nonlinearity of valves may lead to the inaccuracy of the opening and closing time constants calculated based on the whole segment fully open and fully close experimental test curves of the valve. An improved mathematical model of the turbine governor actuator is proposed to reflect the nonlinearity of the valve, in which the main and auxiliary piecewise opening and closing time constants instead of the fixed oil motive opening and closing time constants are adopted to describe the characteristics of the actuator. The main opening and closing time constants are obtained from the linear segments of the whole fully open and close curves. The parameters of proportional integral derivative (PID) controller are identified based on the small disturbance experimental tests of the valve. Then the auxiliary opening and closing time constants and the piecewise opening and closing valve points are determined by the fully open/close experimental tests. Several testing functions are selected to compare genetic algorithm and particle swarm optimization algorithm (GA-PSO) with other basic intelligence algorithms. The effectiveness of the piecewise linear model and its parameters are validated by practical power plant case studies. Jie Zhao, Li Wang, Dichen Liu, and Jun Wang Copyright © 2015 Jie Zhao et al. All rights reserved. Stochastic Multicriteria Acceptability Analysis Based on Choquet Integral Sun, 03 May 2015 06:12:12 +0000 To reflect the interactions among criteria, Choquet integral is employed to stochastic multicriteria acceptability analysis. Models are first given to roughly identify the best and worst ranking orders of each alternative, based on which the weight information spaces are explored to support some alternative for ranking at some position and calculate the acceptability indices of alternatives. Models are then given to analyze the characters of information spaces, which can describe what kind of information supports alternatives for ranking at some position and can give an analysis about the effect of characters on the decision result. The proposed method considers not only the interactions between two criteria, but also the interactions among three, four, and more criteria. The proposed method can be considered as an extension of the existing ones. Meimei Xia Copyright © 2015 Meimei Xia. All rights reserved. Taming Chaos by Linear Regulation with Bound Estimation Tue, 28 Apr 2015 06:50:51 +0000 Chaos control has become an important area of research and consequently many approaches have been proposed to control chaos. This paper proposes a linear regulation method. Different from the existing approaches is that it can provide region of attraction while estimating the bounding behaviour of the norm of the states. The proposed method also possesses design flexibility and can be easily used to cater for special requirement such that control signal should be generated via single input, single state, static feedback and so forth. The applications to the Tigan system, the Genesio chaotic system, the novel chaotic system, and the Lorenz chaotic system justify the above claims. Jiqiang Wang and Weijian Chen Copyright © 2015 Jiqiang Wang and Weijian Chen. All rights reserved. A Time Scales Approach to Coinfection by Opportunistic Diseases Tue, 21 Apr 2015 12:22:35 +0000 Traditional biomedical approaches treat diseases in isolation, but the importance of synergistic disease interactions is now recognized. As a first step we present and analyze a simple coinfection model for two diseases simultaneously affecting a population. The host population is affected by the primary disease, a long-term infection whose dynamics is described by a SIS model with demography, which facilitates individuals acquiring a second disease, secondary (or opportunistic) disease. The secondary disease is instead a short-term infection affecting only the primary infected individuals. Its dynamics is also represented by a SIS model with no demography. To distinguish between short- and long-term infection the complete model is written as a two-time-scale system. The primary disease acts at the slow time scale while the secondary disease does at the fast one, allowing a dimension reduction of the system and making its analysis tractable. We show that an opportunistic disease outbreak might change drastically the outcome of the primary epidemic process, although it does among the outcomes allowed by the primary disease. We have found situations in which either acting on the opportunistic disease transmission or recovery rates or controlling the susceptible and infected population size allows eradicating/promoting disease endemicity. Marcos Marvá, Ezio Venturino, and Rafael Bravo de la Parra Copyright © 2015 Marcos Marvá et al. All rights reserved. On the Study of Oscillating Viscous Flows by Using the Adomian-Padé Approximation Thu, 16 Apr 2015 09:22:18 +0000 The Adomian-Padé technique is applied to examine two oscillating viscous flows, the Stokes’ second problem and the pressure-driven pulsating flow. Main purposes for studying oscillating flows are not only to verify the accuracy of the approximation solution, but also to provide a basis for analyzing more problems by the present method with the help of Fourier analysis. Results show that the Adomian-Padé approximation presents a very excellent behavior in comparison with the exact solution of Stokes’ second problem. For the pulsating flow, only the Adomian decomposition method is required to perform the calculation as the fluid domain is finite where the Padé approximant may not provide a better solution. Based on present results, more problems can be mathematically solved by using the Adomian-Padé technique, the Fourier analysis, and powerful computers. Chi-Min Liu Copyright © 2015 Chi-Min Liu. All rights reserved. MIMO Detection for High Order QAM by Canonical Dual Approach Sun, 05 Apr 2015 13:47:45 +0000 We develop a canonical dual approach for solving the MIMO problem. First, a special linear transformation is introduced to reformulate the original problem into a constrained quadratic programming problem. Then, we derive a canonical dual problem which is piecewise continuous problem with no duality gap. Under certain conditions, the canonical problem becomes a concave maximization dual problem over a convex feasible domain. By getting the stationary point of the canonical dual problem, we can find either an optimal or approximate solution of the original problem. A gradient decent algorithm is proposed to solve the MIMO problem and simulation results are provided to demonstrate the effectiveness of the method. Ye Tian and Jr-Fong Dang Copyright © 2015 Ye Tian and Jr-Fong Dang. All rights reserved. Lightlike Hypersurfaces of Indefinite Generalized Sasakian Space Forms Tue, 31 Mar 2015 12:29:12 +0000 We study lightlike hypersurfaces of an indefinite generalized Sasakian space form , with indefinite trans-Sasakian structure of type , subject to the condition that the structure vector field of is tangent to . First we study the general theory for lightlike hypersurfaces of indefinite trans-Sasakian manifold of type . Next we prove several characterization theorems for lightlike hypersurfaces of an indefinite generalized Sasakian space form. Dae Ho Jin Copyright © 2015 Dae Ho Jin. All rights reserved. Computational Science in Smart Grids and Energy Systems Sun, 29 Mar 2015 07:57:43 +0000 Hongjie Jia, Ned Djilali, Xinghuo Yu, H. D. Chiang, and Gongnan Xie Copyright © 2015 Hongjie Jia et al. All rights reserved.