Mathematical Problems in Engineering The latest articles from Hindawi Publishing Corporation © 2015 , Hindawi Publishing Corporation . All rights reserved. On Analysis of Fractional Navier-Stokes Equations via Nonsingular Solutions and Approximation Wed, 01 Jul 2015 09:40:30 +0000 Until now, all the investigations on fractional or generalized Navier-Stokes equations have been done under some restrictions on the different values that can take the fractional order derivative parameter . In this paper, we analyze the existence and stability of nonsingular solutions to fractional Navier-Stokes equations of type () defined below. In the case where , we show that the stability of the (quadratic) convergence, when exploiting Newton’s method, can only be ensured when the first guess is sufficiently near the solution . We provide interesting well-posedness and existence results for the fractional model in two other cases, namely, when and Emile Franc Doungmo Goufo and Stella Mugisha Copyright © 2015 Emile Franc Doungmo Goufo and Stella Mugisha. All rights reserved. Inverse Problems via the “Generalized Collage Theorem” for Vector-Valued Lax-Milgram-Based Variational Problems Wed, 01 Jul 2015 09:34:51 +0000 We present an extended version of the Generalized Collage Theorem to deal with inverse problems for vector-valued Lax-Milgram systems. Numerical examples show how the method works in practical cases. H. Kunze, D. La Torre, K. Levere, and M. Ruiz Galán Copyright © 2015 H. Kunze et al. All rights reserved. The Optimization of Chiller Loading by Adaptive Neuro-Fuzzy Inference System and Genetic Algorithms Wed, 01 Jul 2015 08:49:48 +0000 A central air-conditioning (AC) system includes the chiller, chiller water pump, cooling water pump, cooling tower, and chilled water secondary pumps. Among these devices, the chiller consumes most power of the central AC system. In this paper, the adaptive neuro-fuzzy inference system (ANFIS) and genetic algorithm (GA) were utilized for optimizing the chiller loading. The ANFIS could construct a power consumption model of the chiller, reduce modeling period, and maintain the accuracy. GA could optimize the chiller loading for better energy efficiency. The simulating results indicated that ANFIS combined with GA could optimize the chiller loading. The power consumption was reduced by 6.32–18.96% when partial load ratio was located at the range of 0.6~0.95. The chiller power consumption model established by ANFIS could also increase the convergence speed. Therefore, the ANFIS with GA could optimize the chiller loading for reducing power consumption. Jyun-Ting Lu, Yung-Chung Chang, and Cheng-Yi Ho Copyright © 2015 Jyun-Ting Lu et al. All rights reserved. Some Identities Involving the Derivative of the First Kind Chebyshev Polynomials Wed, 01 Jul 2015 08:23:25 +0000 We use the combinatorial method and algebraic manipulations to obtain several interesting identities involving the power sums of the derivative of the first kind Chebyshev polynomials. This solved an open problem proposed by Li (2015). Tingting Wang and Han Zhang Copyright © 2015 Tingting Wang and Han Zhang. All rights reserved. Robust Output Feedback Model Predictive Control for a Class of Networked Control Systems with Nonlinear Perturbation Wed, 01 Jul 2015 07:28:09 +0000 This paper is concerned with the design problem of robust dynamic output feedback model predictive controllers for a class of discrete-time systems with time-varying network-induced delays and nonlinear perturbation. The designed controllers achieve on-line suboptimal receding horizon guaranteed cost such that the system can be stabilized for all admissible uncertainties. A novel delay compensation strategy is proposed to eliminate the effects of the time-varying network-induced delays. By using multistep prediction and the receding optimization, the delay-dependent sufficient condition is derived for the existence of delay compensation controllers. By employing the cone complementarity linearization (CCL) idea, a nonlinear minimization problem with linear matrix inequality (LMI) constraints is formulated to design the desired output feedback controllers, and an iterative algorithm involving convex optimization is presented to solve the nonlinear minimization problem. Finally, an example is given to illustrate the feasibility and effectiveness of the proposed results. Qiuxia Chen, Ying Liu, and Haoqi Zhu Copyright © 2015 Qiuxia Chen et al. All rights reserved. Fractional Heat Conduction Models and Thermal Diffusivity Determination Wed, 01 Jul 2015 06:43:01 +0000 The contribution deals with the fractional heat conduction models and their use for determining thermal diffusivity. A brief historical overview of the authors who have dealt with the heat conduction equation is described in the introduction of the paper. The one-dimensional heat conduction models with using integer- and fractional-order derivatives are listed. Analytical and numerical methods of solution of the heat conduction models with using integer- and fractional-order derivatives are described. Individual methods have been implemented in MATLAB and the examples of simulations are listed. The proposal and experimental verification of the methods for determining thermal diffusivity using half-order derivative of temperature by time are listed at the conclusion of the paper. Monika Žecová and Ján Terpák Copyright © 2015 Monika Žecová and Ján Terpák. All rights reserved. Sumudu Transform Method for Analytical Solutions of Fractional Type Ordinary Differential Equations Mon, 29 Jun 2015 12:18:22 +0000 We make use of the so-called Sumudu transform method (STM), a type of ordinary differential equations with both integer and noninteger order derivative. Firstly, we give the properties of STM, and then we directly apply it to fractional type ordinary differential equations, both homogeneous and inhomogeneous ones. We obtain exact solutions of fractional type ordinary differential equations, both homogeneous and inhomogeneous, by using STM. We present some numerical simulations of the obtained solutions and exhibit two-dimensional graphics by means of Mathematica tools. The method used here is highly efficient, powerful, and confidential tool in terms of finding exact solutions. Seyma Tuluce Demiray, Hasan Bulut, and Fethi Bin Muhammad Belgacem Copyright © 2015 Seyma Tuluce Demiray et al. All rights reserved. Inverse Modeling of Human Knee Joint Based on Geometry and Vision Systems for Exoskeleton Applications Mon, 29 Jun 2015 09:57:38 +0000 Current trends in Robotics aim to close the gap that separates technology and humans, bringing novel robotic devices in order to improve human performance. Although robotic exoskeletons represent a breakthrough in mobility enhancement, there are design challenges related to the forces exerted to the users’ joints that result in severe injuries. This occurs due to the fact that most of the current developments consider the joints as noninvariant rotational axes. This paper proposes the use of commercial vision systems in order to perform biomimetic joint design for robotic exoskeletons. This work proposes a kinematic model based on irregular shaped cams as the joint mechanism that emulates the bone-to-bone joints in the human body. The paper follows a geometric approach for determining the location of the instantaneous center of rotation in order to design the cam contours. Furthermore, the use of a commercial vision system is proposed as the main measurement tool due to its noninvasive feature and for allowing subjects under measurement to move freely. The application of this method resulted in relevant information about the displacements of the instantaneous center of rotation at the human knee joint. Eduardo Piña-Martínez and Ernesto Rodriguez-Leal Copyright © 2015 Eduardo Piña-Martínez and Ernesto Rodriguez-Leal. All rights reserved. Smart Demand Response Based on Smart Homes Mon, 29 Jun 2015 07:26:48 +0000 Smart homes (SHs) are crucial parts for demand response management (DRM) of smart grid (SG). The aim of SHs based demand response (DR) is to provide a flexible two-way energy feedback whilst (or shortly after) the consumption occurs. It can potentially persuade end-users to achieve energy saving and cooperate with the electricity producer or supplier to maintain balance between the electricity supply and demand through the method of peak shaving and valley filling. However, existing solutions are challenged by the lack of consideration between the wide application of fiber power cable to the home (FPCTTH) and related users’ behaviors. Based on the new network infrastructure, the design and development of smart DR systems based on SHs are related with not only functionalities as security, convenience, and comfort, but also energy savings. A new multirouting protocol based on Kruskal’s algorithm is designed for the reliability and safety of the SHs distribution network. The benefits of FPCTTH-based SHs are summarized at the end of the paper. Jingang Lai, Hong Zhou, Wenshan Hu, Dongguo Zhou, and Liang Zhong Copyright © 2015 Jingang Lai et al. All rights reserved. Analytical Solution of Space-Time Fractional Fokker-Planck Equation by Homotopy Perturbation Sumudu Transform Method Mon, 29 Jun 2015 07:07:07 +0000 An efficient approach based on homotopy perturbation method by using Sumudu transform is proposed to solve some linear and nonlinear space-time fractional Fokker-Planck equations (FPEs) in closed form. The space and time fractional derivatives are considered in Caputo sense. The homotopy perturbation Sumudu transform method (HPSTM) is a combined form of Sumudu transform, homotopy perturbation method, and He’s polynomials. The nonlinear terms can be easily handled by the use of He’s polynomials. Some examples show that the HPSTM is an effective tool for solving many space time fractional partial differential equations. Ravi Shanker Dubey, Badr Saad T. Alkahtani, and Abdon Atangana Copyright © 2015 Ravi Shanker Dubey et al. All rights reserved. Numerical Simulations of Gravity Driven Reversible Reactive Flows in Homogeneous Porous Media Mon, 29 Jun 2015 06:41:01 +0000 The effect of reversibility on the instability of a miscible vertical reactive flow displacement is examined. A model, where densities and/or viscosities mismatches between the reactants and the chemical product trigger instability, is adopted. The problem is governed by the continuity equation, Darcy’s law, and the convection-diffusion-reaction equations. The problem is formulated and solved numerically using a combination of the highly accurate spectral methods based on Hartley’s transform and the finite-difference technique. Nonlinear simulations were carried out for a variety of parameters to analyse the effects of the reversibility of the chemical reaction on the development of the flow under different scenarios of the frontal instability. In general, faster attenuation in the development and growth of the instability is reported as the reversibility of the chemical reaction increases. However, it was observed that reversibility is capable of triggering instability for particular choices of the densities and viscosities mismatches. In addition, the effect of the reversibility in enhancing the instability was illustrated by presenting the total relative contact area between the reactants and the product. H. Alhumade and J. Azaiez Copyright © 2015 H. Alhumade and J. Azaiez. All rights reserved. Multitarget Tracking with Spatial Nonmaximum Suppressed Sensor Selection Mon, 29 Jun 2015 06:39:21 +0000 Multitarget tracking is one of the most important applications of sensor networks, yet it is an extremely challenging problem since multisensor multitarget tracking itself is nontrivial and the difficulty is further compounded by sensor management. Recently, random finite set based Bayesian framework has opened doors for multitarget tracking with sensor management, which is modelled in the framework of partially observed Markov decision process (POMDP). However, sensor management posed as a POMDP is in essence a combinatorial optimization problem which is NP-hard and computationally unacceptable. In this paper, we propose a novel sensor selection method for multitarget tracking. We first present the sequential multi-Bernoulli filter as a centralized multisensor fusion scheme for multitarget tracking. In order to perform sensor selection, we define the hypothesis information gain (HIG) of a sensor to measure its information quantity when the sensor is selected alone. Then, we propose spatial nonmaximum suppression approach to select sensors with respect to their locations and HIGs. Two distinguished implementations have been provided using the greedy spatial nonmaximum suppression. Simulation results verify the effectiveness of proposed sensor selection approach for multitarget tracking. Liang Ma, Kai Xue, and Ping Wang Copyright © 2015 Liang Ma et al. All rights reserved. Variational Approach for Resolving the Flow of Generalized Newtonian Fluids in Circular Pipes and Plane Slits Mon, 29 Jun 2015 06:29:00 +0000 We use a generic and general variational method to obtain solutions to the flow of generalized Newtonian fluids through circular pipes and plane slits. The new method is not based on the use of the Euler-Lagrange variational principle and hence it is totally independent of our previous approach which is based on this principle. Instead, the method applies a very generic and general optimization approach which can be justified by the Dirichlet principle although this is not the only possible theoretical justification. The results that were obtained from the new method using nine types of fluid are in total agreement, within certain restrictions, with the results obtained from the traditional methods of fluid mechanics as well as the results obtained from the previous variational approach. In addition to being a useful method in its own for resolving the flow field in circular pipes and plane slits, the new variational method lends more support to the old variational method as well as for the use of variational principles in general to resolve the flow of generalized Newtonian fluids and obtain all the quantities of the flow field which include shear stress, local viscosity, rate of strain, speed profile, and volumetric flow rate. Taha Sochi Copyright © 2015 Taha Sochi. All rights reserved. Local Fractional Laplace Variational Iteration Method for Solving Diffusion and Wave Equations on Cantor Sets within Local Fractional Operators Mon, 29 Jun 2015 06:13:22 +0000 The local fractional Laplace variational iteration method (LFLVIM) is employed to handle the diffusion and wave equations on Cantor set. The operators are taken in the local sense. The nondifferentiable approximate solutions are obtained by using the local fractional Laplace variational iteration method, which is the coupling method of local fractional variational iteration method and Laplace transform. Illustrative examples are included to demonstrate the high accuracy and fast convergence of this new algorithm. Hassan Kamil Jassim, Canan Ünlü, Seithuti Philemon Moshokoa, and Chaudry Masood Khalique Copyright © 2015 Hassan Kamil Jassim et al. All rights reserved. Stability and Time Delay Tolerance Analysis Approach for Networked Control Systems Mon, 29 Jun 2015 06:07:29 +0000 Networked control system is a research area where the theory is behind practice. Closing the feedback loop through shared network induces time delay and some of the data could be lost. So the network induced time delay and data loss are inevitable in networked control Systems. The time delay may degrade the performance of control systems or even worse lead to system instability. Once the structure of a networked control system is confirmed, it is essential to identify the maximum time delay allowed for maintaining the system stability which, in turn, is also associated with the process of controller design. Some studies reported methods for estimating the maximum time delay allowed for maintaining system stability; however, most of the reported methods are normally overcomplicated for practical applications. A method based on the finite difference approximation is proposed in this paper for estimating the maximum time delay tolerance, which has a simple structure and is easy to apply. Ashraf F. Khalil and Jihong Wang Copyright © 2015 Ashraf F. Khalil and Jihong Wang. All rights reserved. Co-Design of Event Generator and Dynamic Output Feedback Controller for LTI Systems Sun, 28 Jun 2015 11:58:24 +0000 This paper presents a co-design method of the event generator and the dynamic output feedback controller for a linear time-invariant (LIT) system. The event-triggered condition on the sensor-to-controller and the controller-to-actuator depends on the plant output and the controller output, respectively. A sufficient condition on the existence of the event generator and the dynamic output feedback controller is proposed and the co-design problem can be converted into the feasibility of linear matrix inequalities (LMIs). The LTI system is asymptotically stable under the proposed event-triggered controller and also reduces the computing resources with respect to the time-triggered one. In the end, a numerical example is given to illustrate the effectiveness of the proposed approach. Dan Ma, Junxian Han, Dali Zhang, and Yanjun Liu Copyright © 2015 Dan Ma et al. All rights reserved. Minimum Phase Property of Chebyshev-Sharpened Cosine Filters Sun, 28 Jun 2015 11:08:25 +0000 We prove that the Chebyshev sharpening technique, recently introduced in literature, provides filters with a Minimum Phase (MP) characteristic when it is applied to cosine filters. Additionally, we demonstrate that cascaded expanded Chebyshev-Sharpened Cosine Filters (CSCFs) are also MP filters, and we show that they achieve a lower group delay for similar magnitude characteristics in comparison with traditional cascaded expanded cosine filters. The importance of the characteristics of cascaded expanded CSCFs is also elaborated. The developed examples show improvements in the group delay ranged from 23% to 47% at the cost of a slight increase of usage of hardware resources. For an application of a low-delay decimation filter, the proposed scheme exhibits a 24% lower group delay, with 35% less computational complexity (estimated in Additions per Output Sample) and slightly less usage of hardware elements. Miriam Guadalupe Cruz Jiménez, David Ernesto Troncoso Romero, and Gordana Jovanovic Dolecek Copyright © 2015 Miriam Guadalupe Cruz Jiménez et al. All rights reserved. Singular Points in the Optical Center Distribution of P3P Solutions Sun, 28 Jun 2015 09:54:02 +0000 Multisolution phenomenon is an important issue in P3P problem since, for many real applications, the question of how many solutions could possibly exist for a given P3P problem must at first be addressed before any real implementation. In this work we show that, given 3 control points, if the camera’s optical center is close to one of the 3 toroids generated by rotating the circumcircle of the control point triangle around each one of its 3 sides, there is always an additional solution with its corresponding optical center lying in a small neighborhood of one of the control points, in addition to the original solution. In other words, there always exist at least two solutions for the P3P problem in such cases. Since, for all such additional solutions, their corresponding optical centers must lie in a small neighborhood of control points, the 3 control points constitute the singular points of the P3P solutions. The above result could act as some theoretical guide for P3P practitioners besides its academic value. Lihua Hu, Bo Wang, and Jifu Zhang Copyright © 2015 Lihua Hu et al. All rights reserved. A Selection Method Based on MAGDM with Interval-Valued Intuitionistic Fuzzy Sets Sun, 28 Jun 2015 09:43:06 +0000 As the cloud computing develops rapidly, more and more cloud services appear. Many enterprises tend to utilize cloud service to achieve better flexibility and react faster to market demands. In the cloud service selection, several experts may be invited and many attributes (indicators or goals) should be considered. Therefore, the cloud service selection can be regarded as a kind of Multiattribute Group Decision Making (MAGDM) problems. This paper develops a new method for solving such MAGDM problems. In this method, the ratings of the alternatives on attributes in individual decision matrices given by each expert are in the form of interval-valued intuitionistic fuzzy sets (IVIFSs) which can flexibly describe the preferences of experts on qualitative attributes. First, the weights of experts on each attribute are determined by extending the classical gray relational analysis (GRA) into IVIF environment. Then, based on the collective decision matrix obtained by aggregating the individual matrices, the score (profit) matrix, accuracy matrix, and uncertainty (risk) matrix are derived. A multiobjective programming model is constructed to determine the attribute weights. Subsequently, the alternatives are ranked by employing the overall scores and uncertainties of alternatives. Finally, a cloud service selection problem is provided to illustrate the feasibility and effectiveness of the proposed methods. Gai-Li Xu, Shu-Ping Wan, and Xiao-Lan Xie Copyright © 2015 Gai-Li Xu et al. All rights reserved. Energy Balanced Redeployment Algorithm for Heterogeneous Wireless Sensor Networks Sun, 28 Jun 2015 08:48:45 +0000 Wireless sensor networks (WSNs) have gained worldwide attention in recent years. Since WSNs can be conveniently deployed to monitor a given field of interest, they have been considered as a great long-term economic potential for military, environmental, and scientific applications and so forth. One of the most active areas of research in WSNs is the coverage which is one of the most essential functions to guarantee quality of service (QoS) in WSNs. However, less attention is paid on the heterogeneity of the node and the energy balance of the whole network during the redeployment process. In this work, the energy balanced problems in mobile heterogeneous WSNs redeployment have been analyzed. The virtual force algorithm with extended virtual force model is used to improve the QoS of the deployment. Furthermore energy model is added to enhance or limit the movement of the nodes so that the energy of nodes in the whole WSNs can be balanced and the lifetime of the networks can be prolonged. The simulation results verify the effectiveness of this proposed algorithm. Guang Ye, Baihai Zhang, Senchun Chai, and Lingguo Cui Copyright © 2015 Guang Ye et al. All rights reserved. Optimal Combination of Aircraft Maintenance Tasks by a Novel Simplex Optimization Method Sun, 28 Jun 2015 08:39:54 +0000 Combining maintenance tasks into work packages is not only necessary for arranging maintenance activities, but also critical for the reduction of maintenance cost. In order to optimize the combination of maintenance tasks by fuzzy C-means clustering algorithm, an improved fuzzy C-means clustering model is introduced in this paper. In order to reduce the dimension, variables representing clustering centers are eliminated in the improved cluster model. So the improved clustering model can be directly solved by the optimization method. To optimize the clustering model, a novel nonlinear simplex optimization method is also proposed in this paper. The novel method searches along all rays emitting from the center to each vertex, and those search directions are rightly positive basis. The algorithm has both theoretical convergence and good experimental effect. Taking the optimal combination of some maintenance tasks of a certain aircraft as an instance, the novel simplex optimization method and the clustering model both exhibit excellent performance. Huaiyuan Li, Hongfu Zuo, Dan Lei, Kun Liang, and Tingting Lu Copyright © 2015 Huaiyuan Li et al. All rights reserved. Matrix-Type Network DEA Model with Its Application Based on Input-Output Tables Sun, 28 Jun 2015 08:09:32 +0000 The matrix-type network data envelopment analysis (DEA) model is established for evaluating the relative performance of the matrix-type structure. The existence of solution and property of the new model is given. The equivalence of DEA efficiency and Pareto solutions of corresponding objective programming problem is proved. Using data in input-output tables, the new model is tested and the results show that the new model can be feasible in evaluating the relative performance of the matrix-type structure. Yun Cheng and Huan-Li Gao Copyright © 2015 Yun Cheng and Huan-Li Gao. All rights reserved. Pinning Synchronization of Switched Complex Dynamical Networks Sun, 28 Jun 2015 08:01:51 +0000 Network topology and node dynamics play a key role in forming synchronization of complex networks. Unfortunately there is no effective synchronization criterion for pinning synchronization of complex dynamical networks with switching topology. In this paper, pinning synchronization of complex dynamical networks with switching topology is studied. Two basic problems are considered: one is pinning synchronization of switched complex networks under arbitrary switching; the other is pinning synchronization of switched complex networks by design of switching when synchronization cannot achieved by using any individual connection topology alone. For the two problems, common Lyapunov function method and single Lyapunov function method are used respectively, some global synchronization criteria are proposed and the designed switching law is given. Finally, simulation results verify the validity of the results. Liming Du, Feng Qiao, and Fengying Wang Copyright © 2015 Liming Du et al. All rights reserved. Decentralized Finite-Time Connective Control for a Class of Large-Scale Systems with Different Structural Forms Sun, 28 Jun 2015 07:49:14 +0000 Decentralized finite-time connective control problem for a class of large-scale interconnected systems is studied in this paper. The research aims at two structural forms, namely, the interconnected structure and the one with expanding construction. A new method is proposed to design a decentralized state feedback control law for a large-scale interconnected system so that the closed-loop system is finite-time connectively bounded. The sufficient conditions for the existence of such a decentralized control law are deduced by using LMI method. Another method is presented for a large-scale interconnected system with expanding construction which can be used without changing the decentralized state feedback control law of the original system to design a controller for the newly added subsystem so that both the new subsystem and the resulting expanded system are finite-time connectively bounded. The feasibility and effectiveness of the proposed method are verified by some simulation results. Xiaohua Li, Yang Liu, and Xiaoping Liu Copyright © 2015 Xiaohua Li et al. All rights reserved. Challenges in Atomistic-to-Continuum Coupling Sun, 28 Jun 2015 07:43:34 +0000 This paper is concerned with the design, analysis, and implementation of concurrent coupling approaches where different (atomic and continuous) models are used simultaneously within a single simulation process. Thereby, several problems or pitfalls can happen, for example, the reflection of molecular movements at the “boundary” between the atomic and continuum regions which leads to an unphysical increase in energy in the atomic model. We investigate the problems with the aim of giving an introduction into this field and preventing errors for scientists starting their research towards multiscale methods. Konstantin Fackeldey Copyright © 2015 Konstantin Fackeldey. All rights reserved. Efficiency Improvement of Kalman Filter for GNSS/INS through One-Step Prediction of Matrix Sun, 28 Jun 2015 07:42:06 +0000 To meet the real-time and low power consumption demands in MEMS navigation and guidance field, an improved Kalman filter algorithm for GNSS/INS was proposed in this paper named as one-step prediction of matrix. Quantitative analysis of field test datasets was made to compare the navigation accuracy with the standard algorithm, which indicated that the degradation caused by the simplified algorithm is small enough compared to the navigation errors of the GNSS/INS system itself. Meanwhile, the computation load and time consumption of the algorithm decreased over 50% by the improved algorithm. The work has special significance for navigation applications that request low power consumption and strict real-time response, such as cellphone, wearable devices, and deeply coupled GNSS/INS systems. Qingli Li, Yalong Ban, Xiaoji Niu, Quan Zhang, Linlin Gong, and Jingnan Liu Copyright © 2015 Qingli Li et al. All rights reserved. Dynamic Quantized Predictive Control for Systems with Time-Varying Delay and Packet Loss in the Forward Channel Sun, 28 Jun 2015 07:28:15 +0000 Stability and design of a dynamic quantized predictive control system with time-varying delay and packet loss are studied. For the system with time-varying delay and packet loss in the forward channel, a dynamic quantizer that can minimize the quantized output error is designed and a networked quantized predictive control (NQPC) strategy is proposed to compensate for the delay and packet loss. Stability of the NQPC system is then analyzed and a sufficient stability condition is derived and presented in the form of matrix inequality. Finally, both simulation and experimental results are given to demonstrate the effectiveness of the proposed approach. Mu Li, Lihua Dou, Jian Sun, and Di Wang Copyright © 2015 Mu Li et al. All rights reserved. The Design of Robust Controller for Networked Control System with Time Delay Sun, 28 Jun 2015 07:21:00 +0000 This paper considers the stability and control problem of networked control systems with time delay. Taking into account the influence of network with delay, unknown input disturbance, and uncertainties of the system modeling, meanwhile we establish a precise, closed-loop model for networked control systems with time delay. By selecting a proper Lyapunov-Krasovskii function and using Lyapunov theorem, a sufficient condition for stability of the system in the form of LMI is demonstrated, corresponding controller parameters are acquired, and the convergence of the control algorithm is proved. The simulation example shows that the construction of the network robust control system with time delay indeed improves the stability performance of the system, which indicates the effectiveness of the design. Zhongda Lu, Lijing Wang, Fengbin Zhang, and Fengxia Xu Copyright © 2015 Zhongda Lu et al. All rights reserved. Guaranteed Cost Fault-Tolerant Control for Networked Control Systems with Sensor Faults Sun, 28 Jun 2015 07:20:24 +0000 For the large scale and complicated structure of networked control systems, time-varying sensor faults could inevitably occur when the system works in a poor environment. Guaranteed cost fault-tolerant controller for the new networked control systems with time-varying sensor faults is designed in this paper. Based on time delay of the network transmission environment, the networked control systems with sensor faults are modeled as a discrete-time system with uncertain parameters. And the model of networked control systems is related to the boundary values of the sensor faults. Moreover, using Lyapunov stability theory and linear matrix inequalities (LMI) approach, the guaranteed cost fault-tolerant controller is verified to render such networked control systems asymptotically stable. Finally, simulations are included to demonstrate the theoretical results. Qixin Zhu, Kaihong Lu, Guangming Xie, and Yonghong Zhu Copyright © 2015 Qixin Zhu et al. All rights reserved. Banknote Validation through an Embedded RFID Chip and an NFC-Enabled Smartphone Sun, 28 Jun 2015 06:48:14 +0000 With the new, state-of-the-art printing devices and equipment, there has been rapid growth in the counterfeiting of banknotes. Traditional security features on banknotes are easy targets for counterfeiters, and they can easily imitate the original banknotes with fake ones. Conventional methods for validating currency require specialized devices for the authentication of banknotes. However, cost and lack of mobility of sophisticated banknote validation devices are big problems for general consumers. Modern digital solutions are attempting to complement the traditional security features through embedding radio frequency identification (RFID) chips in the banknotes, for example, Euro currency. Unfortunately, the requirement of specialized RFID readers for banknote validation impedes their widespread proliferation among consumers. To overcome this problem, a new method of banknote validation using an RFID chip and an NFC-enabled smartphone is presented. The consumer sends a banknote validation request to the Monetary Agency () using her or his smartphone and an Internet connection. The replies by sending a random challenge to the consumer’s smartphone. The RFID chip in the banknote receives the challenge, via the NFC, and calculates an equivalent response to the ’s challenge. If any of the messages are incorrect, authentication is denied. By the proposed method, consumers can easily and instantly check the originality of currency notes with the using their smartphones and an Internet connection. The proposed system is less expensive, computationally, than regular methods and preserves the privacy of people who carry banknotes. Mohamed Hamdy Eldefrawy and Muhammad Khurram Khan Copyright © 2015 Mohamed Hamdy Eldefrawy and Muhammad Khurram Khan. All rights reserved.