Journal of Electrical and Computer Engineering http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2014 , Hindawi Publishing Corporation . All rights reserved. Broadband Adaptive RCS Computation through Characteristic Basis Function Method Thu, 21 Aug 2014 00:00:00 +0000 http://www.hindawi.com/journals/jece/2014/195409/ A broadband radar cross section (RCS) calculation approach is proposed based on the characteristic basis function method (CBFM). In the proposed approach, the desired arbitrary frequency band is adaptively divided into multiple subband in consideration of the characteristic basis functions (CBFs) number, which can reduce the universal characteristic basis functions (UCBFs) numbers after singular value decomposition (SVD) procedure at lower subfrequency band. Then, the desired RCS data can be obtained by splicing the RCS data in each subfrequency band. Numerical results demonstrate that the proposed method achieve a high accuracy and efficiency over a wide frequency range. Guohua Wang and Yufa Sun Copyright © 2014 Guohua Wang and Yufa Sun. All rights reserved. Design of Dual-Band Bandpass Filter Using Dual-Mode Defected Stub Loaded Resonator Mon, 21 Jul 2014 12:12:50 +0000 http://www.hindawi.com/journals/jece/2014/176560/ A novel approach for designing a dual-band bandpass filter (BPF) using defected stub loaded resonator (DSLR) is presented in this paper. The proposed DSLR consists of two fundamental resonant modes and some resonant characteristics have been investigated by EM software of Ansoft HFSS. Then, based on two coupled DSLRs, a dual-band response BPF that operates at 2.4 GHz and 3.5 GHz is designed and implemented for WLAN and WIMAX application. The first passband is constructed by two lower frequencies of the coupled DSLRs and the second passband is produced by two higher ones; the coupling scheme of them is also given. Finally, the dual-band BPF is fabricated and measured; a good agreement between simulation and measurement is obtained, which verifies the validity of the design methodology. Dechang Huang and Zhaodi Huang Copyright © 2014 Dechang Huang and Zhaodi Huang. All rights reserved. A Three-Dimensional Wireless Indoor Localization System Sun, 20 Jul 2014 09:28:00 +0000 http://www.hindawi.com/journals/jece/2014/149016/ Indoor localization, an emerging technology in location based service (LBS), is now playing a more and more important role both in commercial and in civilian industry. Global position system (GPS) is the most popular solution in outdoor localization field, and the accuracy is around 10 meter error in positioning. However, with complex obstacles in buildings, problems rise in the “last mile” of localization field, which encourage a momentum of indoor localization. The traditional indoor localization system is either range-based or fingerprinting-based, which requires a lot of time and efforts to do the predeployment. In this paper, we present a 3-dimensional on-demand indoor localization system (3D-ODIL), which can be fingerprint-free and deployed rapidly in a multistorey building. The 3D-ODIL consists of two phases, vertical localization and horizontal localization. On vertical direction, we propose multistorey differential (MSD) algorithm and implement it to fulfill the vertical localization, which can greatly reduce the number of anchors deployed. We use enhanced field division (EFD) algorithm to conduct the horizontal localization. EFD algorithm is a range-free algorithm, the main idea of which is to dynamically divide the field within different signature area and position the target. The accuracy and performance have been validated through our extensive analysis and systematic experiments. Ping Yi, Minjie Yu, Ziqiao Zhou, Wei Xu, Qingquan Zhang, and Ting Zhu Copyright © 2014 Ping Yi et al. All rights reserved. Asynchronous Advanced Encryption Standard Hardware with Random Noise Injection for Improved Side-Channel Attack Resistance Sun, 20 Jul 2014 07:14:28 +0000 http://www.hindawi.com/journals/jece/2014/837572/ This work presents the design, hardware implementation, and performance analysis of novel asynchronous AES (advanced encryption standard) Key Expander and Round Function, which offer increased side-channel attack (SCA) resistance. These designs are based on a delay-insensitive (DI) logic paradigm known as null convention logic (NCL), which supports useful properties for resisting SCAs including dual-rail encoding, clock-free operation, and monotonic transitions. Potential benefits include reduced and more uniform switching activities and reduced signal-to-noise (SNR) ratio. A novel method to further augment NCL AES hardware with random voltage scaling technique is also presented for additional security. Thereby, the proposed components leak significantly less side-channel information than conventional clocked approaches. To quantitatively verify such improvements, functional verification and WASSO (weighted average simultaneous switching output) analysis have been carried out on both conventional synchronous approach and the proposed NCL based approach using Mentor Graphics ModelSim and Xilinx simulation tools. Hardware implementation has been carried out on both designs exploiting a specified side-channel attack standard evaluation FPGA board, called SASEBO-GII, and the corresponding power waveforms for both designs have been collected. Along with the results of software simulations, we have analyzed the collected waveforms to validate the claims related to benefits of the proposed cryptohardware design approach. Siva Kotipalli, Yong-Bin Kim, and Minsu Choi Copyright © 2014 Siva Kotipalli et al. All rights reserved. Multiport Technology: New Perspectives and Applications Mon, 07 Jul 2014 11:22:54 +0000 http://www.hindawi.com/journals/jece/2014/194649/ Serioja Ovidiu Tatu, Adriana Serban, Alexander Koelpin, and Mohamed Helaoui Copyright © 2014 Serioja Ovidiu Tatu et al. All rights reserved. Improved Data Transmission Scheme of Network Coding Based on Access Point Optimization in VANET Thu, 03 Jul 2014 00:00:00 +0000 http://www.hindawi.com/journals/jece/2014/185412/ VANET is a hot spot of intelligent transportation researches. For vehicle users, the file sharing and content distribution through roadside access points (AP) as well as the vehicular ad hoc networks (VANET) have been an important complement to that cellular network. So the AP deployment is one of the key issues to improve the communication performance of VANET. In this paper, an access point optimization method is proposed based on particle swarm optimization algorithm. The transmission performances of the routing protocol with random linear network coding before and after the access point optimization are analyzed. The simulation results show the optimization model greatly affects the VANET transmission performances based on network coding, and it can enhance the delivery rate by 25% and 14% and reduce the average delay of transmission by 38% and 33%. Zhe Yang, Lingzhi Li, Wenqiang Yao, Kaisheng Xu, and Dongxin Tang Copyright © 2014 Zhe Yang et al. All rights reserved. A New Intrusion Detection System Based on KNN Classification Algorithm in Wireless Sensor Network Mon, 30 Jun 2014 10:31:50 +0000 http://www.hindawi.com/journals/jece/2014/240217/ The Internet of Things has broad application in military field, commerce, environmental monitoring, and many other fields. However, the open nature of the information media and the poor deployment environment have brought great risks to the security of wireless sensor networks, seriously restricting the application of wireless sensor network. Internet of Things composed of wireless sensor network faces security threats mainly from Dos attack, replay attack, integrity attack, false routing information attack, and flooding attack. In this paper, we proposed a new intrusion detection system based on -nearest neighbor (-nearest neighbor, referred to as KNN below) classification algorithm in wireless sensor network. This system can separate abnormal nodes from normal nodes by observing their abnormal behaviors, and we analyse parameter selection and error rate of the intrusion detection system. The paper elaborates on the design and implementation of the detection system. This system has achieved efficient, rapid intrusion detection by improving the wireless ad hoc on-demand distance vector routing protocol (Ad hoc On-Demand Distance the Vector Routing, AODV). Finally, the test results show that: the system has high detection accuracy and speed, in accordance with the requirement of wireless sensor network intrusion detection. Wenchao Li, Ping Yi, Yue Wu, Li Pan, and Jianhua Li Copyright © 2014 Wenchao Li et al. All rights reserved. The Effect of Applying 2D Enhancement Algorithms on 3D Video Content Thu, 19 Jun 2014 00:00:00 +0000 http://www.hindawi.com/journals/jece/2014/601392/ Enhancement algorithms are typically applied to video content to increase their appeal to viewers. Such algorithms are readily available in the literature and are already widely applied in, for example, commercially available TVs. On the contrary, not much research has been done on enhancing stereoscopic 3D video content. In this paper, we present research focused on the effect of applying enhancement algorithms used for 2D content on 3D side-by-side content. We evaluate both offline enhancement of video content based on proprietary enhancement algorithms and real-time enhancement in the TVs. This is done using stereoscopic TVs with active shutter glasses, viewed both in their 2D and 3D viewing mode. The results of this research show that 2D enhancement algorithms are a viable first approach to enhance 3D content. In addition to video quality degradation due to the loss of spatial resolution as a consequence of the 3D video format, brightness reduction inherent to polarized or shutter glasses similarly degrades video quality. We illustrate the benefit of providing brightness enhancement for stereoscopic displays. Sin Lin Wu, Jorge E. Caviedes, Lina Karam, and Ingrid Heynderickx Copyright © 2014 Sin Lin Wu et al. All rights reserved. Application of Hybrid MOPSO Algorithm to Optimal Reactive Power Dispatch Problem Considering Voltage Stability Wed, 18 Jun 2014 13:35:09 +0000 http://www.hindawi.com/journals/jece/2014/124136/ This study presents a novel hybrid multiobjective particle swarm optimization (HMOPSO) algorithm to solve the optimal reactive power dispatch (ORPD) problem. This problem is formulated as a challenging nonlinear constrained multiobjective optimization problem considering three objectives, that is, power losses minimization, voltage profile improvement, and voltage stability enhancement simultaneously. In order to attain better convergence and diversity, this work presents the use of combing the classical MOPSO with Gaussian probability distribution, chaotic sequences, dynamic crowding distance, and self-adaptive mutation operator. Moreover, multiple effective strategies, such as mixed-variable handling approach, constraint handling technique, and stopping criteria, are employed. The effectiveness of the proposed algorithm for solving the ORPD problem is validated on the standard IEEE 30-bus and IEEE 118-bus systems under nominal and contingency states. The obtained results are compared with classical MOPSO, nondominated sorting genetic algorithm (NSGA-II), multiobjective evolutionary algorithm based on decomposition (MOEA/D), and other methods recently reported in the literature from the point of view of Pareto fronts, extreme, solutions and multiobjective performance metrics. The numerical results demonstrate the superiority of the proposed HMOPSO in solving the ORPD problem while strictly satisfying all the constraints. Yujiao Zeng and Yanguang Sun Copyright © 2014 Yujiao Zeng and Yanguang Sun. All rights reserved. Joint Design of Transmission Rate and Control for Wireless Sensor Networked Control Systems Wed, 28 May 2014 09:41:26 +0000 http://www.hindawi.com/journals/jece/2014/158404/ This paper is concerned with transmission rate and control codesign of wireless sensor networked control systems (WSNCS) with time-varying delay. Jointly designing transmission rate and control is an attractive paradigm for WSNCS, since the control performance of WSNCS is highly sensitive to resource-constrained communication networks. The main idea of devised scheme is searching an optimal event-triggered transmission condition on the premise that wireless link capacity constraint is satisfied and stability of systems is guaranteed. The main aim of devised scheme is to greatly optimize control performance of WSNCS. First, two wireless network architectures characterized by multihop and star topology are put forward. Secondly, a model of WSNCS with event-triggered transmission mechanism is constructed. It is followed by stability analysis of WSNCS to obtain the asymptotical stability condition of systems. And then a search algorithm is presented for transmission rate and control codesign. Finally, numerical examples are given to illustrate the effectiveness of the proposed method. Jinna Li, Peng Zeng, Xuejun Zong, Meng Zheng, and Xiaoling Zhang Copyright © 2014 Jinna Li et al. All rights reserved. Two-Factor User Authentication with Key Agreement Scheme Based on Elliptic Curve Cryptosystem Mon, 19 May 2014 07:59:20 +0000 http://www.hindawi.com/journals/jece/2014/423930/ A password authentication scheme using smart card is called two-factor authentication scheme. Two-factor authentication scheme is the most accepted and commonly used mechanism that provides the authorized users a secure and efficient method for accessing resources over insecure communication channel. Up to now, various two-factor user authentication schemes have been proposed. However, most of them are vulnerable to smart card loss attack, offline password guessing attack, impersonation attack, and so on. In this paper, we design a password remote user authentication with key agreement scheme using elliptic curve cryptosystem. Security analysis shows that the proposed scheme has high level of security. Moreover, the proposed scheme is more practical and secure in contrast to some related schemes. Juan Qu and Xiao-Ling Tan Copyright © 2014 Juan Qu and Xiao-Ling Tan. All rights reserved. Programmed Tool for Quantifying Reliability and Its Application in Designing Circuit Systems Sun, 18 May 2014 00:00:00 +0000 http://www.hindawi.com/journals/jece/2014/410758/ As CMOS technology scales down to nanotechnologies, reliability continues to be a decisive subject in the design entry of nanotechnology-based circuit systems. As a result, several computational methodologies have been proposed to evaluate reliability of those circuit systems. However, the process of computing reliability has become very time consuming and troublesome as the computational complexity grows exponentially with the dimension of circuit systems. Therefore, being able to speed up the task of reliability analysis is fast becoming necessary in designing modern logic integrated circuits. For this purpose, the paper firstly looks into developing a MATLAB-based automated reliability tool by incorporating the generalized form of the existing computational approaches that can be found in the current literature. Secondly, a comparative study involving those existing computational approaches is carried out on a set of standard benchmark test circuits. Finally, the paper continues to find the exact error bound for individual faulty gates as it plays a significant role in the reliability of circuit systems. N. S. S. Singh Copyright © 2014 N. S. S. Singh. All rights reserved. Face Recognition Method Based on Fuzzy 2DPCA Thu, 15 May 2014 07:06:53 +0000 http://www.hindawi.com/journals/jece/2014/919041/ 2DPCA, which is one of the most important face recognition methods, is relatively sensitive to substantial variations in light direction, face pose, and facial expression. In order to improve the recognition performance of the traditional 2DPCA, a new 2DPCA algorithm based on the fuzzy theory is proposed in this paper, namely, the fuzzy 2DPCA (F2DPCA). In this method, applying fuzzy K-nearest neighbor (FKNN), the membership degree matrix of the training samples is calculated, which is used to get the fuzzy means of each class. The average of fuzzy means is then incorporated into the definition of the general scatter matrix with anticipation that it can improve classification result. The comprehensive experiments on the ORL, the YALE, and the FERET face database show that the proposed method can improve the classification rates and reduce the sensitivity to variations between face images caused by changes in illumination, face expression, and face pose. Xiaodong Li Copyright © 2014 Xiaodong Li. All rights reserved. Simulation and Test of a Fuel Cell Hybrid Golf Cart Tue, 13 May 2014 00:00:00 +0000 http://www.hindawi.com/journals/jece/2014/568906/ This paper establishes the simulation model of fuel cell hybrid golf cart (FCHGC), which applies the non-GUI mode of the Advanced Vehicle Simulator (ADVISOR) and the genetic algorithm (GA) to optimize it. Simulation of the objective function is composed of fuel consumption and vehicle dynamic performance; the variables are the fuel cell stack power sizes and the battery numbers. By means of simulation, the optimal parameters of vehicle power unit, fuel cell stack, and battery pack are worked out. On this basis, GUI mode of ADVISOR is used to select the rated power of vehicle motor. In line with simulation parameters, an electrical golf cart is refitted by adding a 2 kW hydrogen air proton exchange membrane fuel cell (PEMFC) stack system and test the FCHGC. The result shows that the simulation data is effective but it needs improving compared with that of the real cart test. Jingming Liang and Qifei Jian Copyright © 2014 Jingming Liang and Qifei Jian. All rights reserved. Innovative Techniques for Power Consumption Saving in Telecommunication Networks Mon, 05 May 2014 12:38:48 +0000 http://www.hindawi.com/journals/jece/2014/684987/ Vincenzo Eramo, Xavier Hesselbach-Serra, and Yan Luo Copyright © 2014 Vincenzo Eramo et al. All rights reserved. A-LNT: A Wireless Sensor Network Platform for Low-Power Real-Time Voice Communications Sun, 04 May 2014 13:42:53 +0000 http://www.hindawi.com/journals/jece/2014/394376/ Combining wireless sensor networks and voice communication for multidata hybrid wireless network suggests possible applications in numerous fields. However, voice communication and sensor data transmissions have significant differences, Meanwhile, high-speed massive real-time voice data processing poses challenges for hardware design, protocol design, and especially power management. In this paper, we present a wireless audio sensor network platform A-LNT and study and discuss key elements for systematic design and implementation: node hardware design, low-power voice codec and processing, wireless network topology, hybrid MAC protocol design based on superframe, radio channel allocation, and clock synchronization. Furthermore, we discuss energy management methods such as address filtering and efficient power management in detail. The experimental and simulation results show that A-LNT is a lightweight, low-power, low-speed, and high-performance wireless sensor network platform for multichannel real-time voice communications. Yong Fu, Qiang Guo, and Changying Chen Copyright © 2014 Yong Fu et al. All rights reserved. A Doping Bits Based BP Decoding for Rateless Distributed Source Coding Applications Wed, 23 Apr 2014 11:41:10 +0000 http://www.hindawi.com/journals/jece/2014/467628/ A novel doping bits based belief propagation decoding algorithm, for rate-adaptive LDPC codes based on fixed bipartite graph code, is proposed. The proposed work modifies the decoding algorithm, by converting the puncturing nodes to regular source nodes and by following the encoding rule at the decoder. The transmitted doping bits in place of punctured bits, with the modified decoding algorithm at the decoder, feed all the punctured nodes with reliable log likelihood ratios. This enables the proposed decoding algorithm to recover all punctured nodes in the early iteration. The fast convergence leads to decoder complexity reduction while providing considerable improvement in performance. N. M. Masoodhu Banu and S. Sasikumar Copyright © 2014 N. M. Masoodhu Banu and S. Sasikumar. All rights reserved. Cross-Modality 2D-3D Face Recognition via Multiview Smooth Discriminant Analysis Based on ELM Wed, 23 Apr 2014 10:00:46 +0000 http://www.hindawi.com/journals/jece/2014/584241/ In recent years, 3D face recognition has attracted increasing attention from worldwide researchers. Rather than homogeneous face data, more and more applications require flexible input face data nowadays. In this paper, we propose a new approach for cross-modality 2D-3D face recognition (FR), which is called Multiview Smooth Discriminant Analysis (MSDA) based on Extreme Learning Machines (ELM). Adding the Laplacian penalty constrain for the multiview feature learning, the proposed MSDA is first proposed to extract the cross-modality 2D-3D face features. The MSDA aims at finding a multiview learning based common discriminative feature space and it can then fully utilize the underlying relationship of features from different views. To speed up the learning phase of the classifier, the recent popular algorithm named Extreme Learning Machine (ELM) is adopted to train the single hidden layer feedforward neural networks (SLFNs). To evaluate the effectiveness of our proposed FR framework, experimental results on a benchmark face recognition dataset are presented. Simulations show that our new proposed method generally outperforms several recent approaches with a fast training speed. Yi Jin, Jiuwen Cao, Qiuqi Ruan, and Xueqiao Wang Copyright © 2014 Yi Jin et al. All rights reserved. An FPGA-Integrated Time-to-Digital Converter Based on a Ring Oscillator for Programmable Delay Line Resolution Measurement Sun, 13 Apr 2014 13:22:20 +0000 http://www.hindawi.com/journals/jece/2014/230803/ We describe the architecture of a time-to-digital converter (TDC), specially intended to measure the delay resolution of a programmable delay line (PDL). The configuration, which consists of a ring oscillator, a frequency divider (FD), and a period measurement circuit (PMC), is implemented in a field programmable gate array (FPGA) device. The ring oscillator realized in loop containing a PDL and a look-up table (LUT) generates periodic oscillatory pulses. The FD amplifies the oscillatory period from nanosecond range to microsecond range. The time-to-digital conversion is based on counting the number of clock cycles between two consecutive pulses of the FD by the PMC. Experiments have been conducted to verify the performance of the TDC. The achieved relative errors for four PDLs are within 0.50%–1.21% and the TDC has an equivalent resolution of about 0.4 ps. Chao Chen, Shengwei Meng, Zhenghuan Xia, Guangyou Fang, and Hejun Yin Copyright © 2014 Chao Chen et al. All rights reserved. Evaluation of Power Saving and Feasibility Study of Migrations Solutions in a Virtual Router Network Sun, 30 Mar 2014 13:25:46 +0000 http://www.hindawi.com/journals/jece/2014/910658/ The power consumption of the network equipment has increased significantly and some strategies to contain the power used in the IP network are needed. Among the green networking strategies, the virtualization class and in particular the deployment of migrating virtual routers can lead to a high energy saving. It consists in migrating virtual routers in fewer physical nodes when the traffic decreases allowing for a power consumption saving. In this paper we formulate the problem of minimizing the power consumption as a Mixed Integer Linear Programming (MILP) problem. Due to the hard complexity of the introduced MILP problem, we propose a heuristic for the migration of virtual routers among physical devices in order to turn off as many nodes as possible and save power according to the compliance with network node and link capacity constraints. We show that 50% of nodes may be turned off in the case of a real provider network when traffic percentage reduction of 80% occurs. Finally we also perform a feasibility study by means of an experimental test-bed to evaluate migration time of a routing plane based on QUAGGA routing software. V. Eramo, S. Testa, and E. Miucci Copyright © 2014 V. Eramo et al. All rights reserved. Energy-Aware Base Stations: The Effect of Planning, Management, and Femto Layers Sun, 30 Mar 2014 11:54:28 +0000 http://www.hindawi.com/journals/jece/2014/190586/ We compare the performance of three base station management schemes on three different network topologies. In addition, we explore the effect of offloading traffic to heterogeneous femtocell layer upon energy savings taking into account the increase of base station switch-off time intervals. Fairness between mobile operator and femtocell owners is maintained since current femtocell technologies present flat power consumption curves with respect to served traffic. We model two different user-to-femtocell association rules in order to capture realistic and maximum gains from the heterogeneous network. To provide accurate findings and a holistic overview of the techniques, we explore a real urban district where channel estimations and power control are modeled using deterministic algorithms. Finally, we explore energy efficiency metrics that capture savings in the mobile network operator, the required watts per user and watts per bitrate. It is found that the newly established pseudo distributed management scheme is the most preferable solution for practical implementations and together with the femotcell layer the network can handle dynamic load control that is regarded as the basic element of future demand response programs. G. Koutitas, L. Chiaraviglio, Delia Ciullo, M. Meo, and L. Tassiulas Copyright © 2014 G. Koutitas et al. All rights reserved. Facing the Reality: Validation of Energy Saving Mechanisms on a Testbed Thu, 27 Mar 2014 06:16:42 +0000 http://www.hindawi.com/journals/jece/2014/806960/ Two energy saving approaches, called Fixed Upper Fixed Lower (FUFL) and Dynamic Upper Fixed Lower (DUFL), switching off idle optical Gigabit Ethernet (GbE) interfaces during low traffic periods, have been implemented on a testbed. We show on a simple network scenario that energy can be saved using off-the-shelf equipment not explicitly designed for dynamic on/off operation. No packet loss is experienced in our experiments. We indicate the need for faster access to routers in order to perform the reconfiguration. This is particularly important for the more sophisticated energy saving approaches such as DUFL, since FUFL can be implemented locally. Edion Tego, Filip Idzikowski, Luca Chiaraviglio, Angelo Coiro, and Francesco Matera Copyright © 2014 Edion Tego et al. All rights reserved. Property-Based Anonymous Attestation in Trusted Cloud Computing Tue, 25 Mar 2014 13:19:15 +0000 http://www.hindawi.com/journals/jece/2014/687158/ In the remote attestation on Trusted Computer (TC) computing mode TCCP, the trusted computer TC has an excessive burden, and anonymity and platform configuration information security of computing nodes cannot be guaranteed. To overcome these defects, based on the research on and analysis of current schemes, we propose an anonymous proof protocol based on property certificate. The platform configuration information is converted by the matrix algorithm into the property certificate, and the remote attestation is implemented by trusted ring signature scheme based on Strong RSA Assumption. By the trusted ring signature scheme based on property certificate, we achieve the anonymity of computing nodes and prevent the leakage of platform configuration information. By simulation, we obtain the computational efficiency of the scheme. We also expand the protocol and obtain the anonymous attestation based on ECC. By scenario comparison, we obtain the trusted ring signature scheme based on RSA, which has advantages with the growth of the ring numbers. Zhen-Hu Ning, Wei Jiang, Jing Zhan, and Peng Liang Copyright © 2014 Zhen-Hu Ning et al. All rights reserved. A Simple Power Management Scheme with Enhanced Stability for a Solar PV/Wind/Fuel Cell/Grid Fed Hybrid Power Supply Designed for Industrial Loads Sun, 16 Mar 2014 08:40:20 +0000 http://www.hindawi.com/journals/jece/2014/319017/ This paper proposes a new power conditioner topology with an intelligent power management controller that integrates multiple renewable energy sources such as solar energy, wind energy, and fuel cell energy with battery and AC grid supply as backup to make the best use of their operating characteristics with better reliability than that could be obtained by single renewable energy source based power supply. The proposed embedded controller is programmed to perform MPPT for solar PV panel and WTG, SOC estimation and battery, maintaining a constant voltage at PCC and power flow control by regulating the reference currents of the controller in an instantaneous basis. The instantaneous variation in reference currents of the controller enhances the controller response as it accommodates the effect of continuously varying solar insolation and wind speed in the power management. It also prioritizes the sources for consumption to achieve maximum usage of green energy than grid energy. The simulation results of the proposed power management system with real-time solar radiation and wind velocity data collected from solar centre, KEC, and experimental results for a sporadically varying load demand are presented in this paper and the results are encouraging from reliability and stability perspectives. S. Saravanan and S. Thangavel Copyright © 2014 S. Saravanan and S. Thangavel. All rights reserved. Design of a Traffic-Aware Governor for Green Routers Wed, 12 Mar 2014 00:00:00 +0000 http://www.hindawi.com/journals/jece/2014/683408/ Today the reduction of energy consumption in telecommunications networks is one of the main goals to be pursued by manufacturers and researchers. In this context, the paper focuses on routers that achieve energy saving by applying the frequency scaling approach. The target is to propose an analytical model to support designers in choosing the main configuration parameters of the Router Governor in order to meet Quality of Service (QoS) requirements while maximizing energy saving gain. More specifically, the model is used to evaluate the input traffic impacts on the choice of the active router clock frequencies and on the overall green router performance. A case study based on the open NetFPGA reference router is considered to show how the proposed model can be easily applied to a real case scenario. Alfio Lombardo, Vincenzo Riccobene, and Giovanni Schembra Copyright © 2014 Alfio Lombardo et al. All rights reserved. Smart Power Management and Delay Reduction for Target Tracking in Wireless Sensor Networks Tue, 11 Mar 2014 16:40:52 +0000 http://www.hindawi.com/journals/jece/2014/641720/ Energy efficiency and data transmission delay are critical issues for mobile target tracking wireless sensor networks, in which abundant sensor nodes are deployed to collect the target information from the sensing field. At present, many existing works have been concentrated on extending network lifetime, while less emphasis was placed on both transmission delay reduction and the adaptive sleep of sensor nodes considering the application constraints. In this paper, we propose a smart power management and delay reduction approach for target tracking based on a grid network structure, where sensor nodes adjust their sleep intervals according to the distance between the node and the moving target. Sensor nodes can distributedly decide their sleeping time using the information from their neighbors. Furthermore, we propose a real-time chain to relay the sensed data for transmission delay reduction. The proposed approach allows sensor nodes that are far away from the target to sleep more and make the target information forward to the sink in time. Experimental results verify that, in contrast to adaptive coordinate and local power management protocols, the proposed approach achieves a significant energy saving while maintaining a short transmission delay. Juan Feng, Baowang Lian, and Hongwei Zhao Copyright © 2014 Juan Feng et al. All rights reserved. Multiprotocol Communication Interface PMSM Control on Account of Industrial Configuration Software Mon, 10 Mar 2014 07:03:09 +0000 http://www.hindawi.com/journals/jece/2014/651216/ The purpose is to achieve drive controller of PMSM connect with industrial control configuration software seamless and to meet the industrial configuration software in the demand for motor to realize intelligent control. A software interface was designed and implemented about motor drive controller and the PC the industrial control configuration base on Modbus_RTU serial communication protocol of industrial control. One kind of design and implementation methods have been proposed in the communication interfaces for industrial applications scalable multiselectivity. Using the latest high-performance multiprotocol transceiver device pin programmable SP339 as the lower machine communications chip designed optional multi-interface hardware circuit with DSP TMS320F2812 as the processor. The interface program was studied with regard to C language software of lower machine and control configuration software of PC. Database creation, data acquisition, and animation links of PC configuration software are realized. Online debugging results meet the design requirements on account of PC control configuration software and the lower machine controller hardware and software. Li-guo Zhang and Man-feng Dou Copyright © 2014 Li-guo Zhang and Man-feng Dou. All rights reserved. Image Denoising Using Fourth Order Wiener Filter with Wavelet Quadtree Decomposition Sun, 02 Mar 2014 07:27:59 +0000 http://www.hindawi.com/journals/jece/2014/108393/ Visual information transmitted in the form of digital images is becoming a major method of communication in the modern age, but the image obtained after transmission is often corrupted with noise. The received image needs processing before it can be used in applications. Image denoising involves the manipulation of the image data to produce a visually high quality image. This paper uses the fourth order nonlinear wiener filter with wavelet quadtree decomposition and median absolute deviation. It will be shown that this new algorithm is comparable to other algorithms like BM3D, LPG-PCA, and KSVD. Issam Dagher and Catherine Taleb Copyright © 2014 Issam Dagher and Catherine Taleb. All rights reserved. Hybrid Optical Switching for Data Center Networks Thu, 27 Feb 2014 11:59:24 +0000 http://www.hindawi.com/journals/jece/2014/139213/ Current data centers networks rely on electronic switching and point-to-point interconnects. When considering future data center requirements, these solutions will raise issues in terms of flexibility, scalability, performance, and energy consumption. For this reason several optical switched interconnects, which make use of optical switches and wavelength division multiplexing (WDM), have been recently proposed. However, the solutions proposed so far suffer from low flexibility and are not able to provide service differentiation. In this paper we introduce a novel data center network based on hybrid optical switching (HOS). HOS combines optical circuit, burst, and packet switching on the same network. In this way different data center applications can be mapped to the optical transport mechanism that best suits their traffic characteristics. Furthermore, the proposed HOS network achieves high transmission efficiency and reduced energy consumption by using two parallel optical switches. We consider the architectures of both a traditional data center network and the proposed HOS network and present a combined analytical and simulation approach for their performance and energy consumption evaluation. We demonstrate that the proposed HOS data center network achieves high performance and flexibility while considerably reducing the energy consumption of current solutions. Matteo Fiorani, Slavisa Aleksic, and Maurizio Casoni Copyright © 2014 Matteo Fiorani et al. All rights reserved. Activity-Based Scene Decomposition for Topology Inference of Video Surveillance Network Wed, 26 Feb 2014 06:08:06 +0000 http://www.hindawi.com/journals/jece/2014/645145/ The topology inference is the study of spatial and temporal relationships among cameras within a video surveillance network. We propose a novel approach to understand activities based on the visual coverage of a video surveillance network. In our approach, an optimal camera placement scheme is firstly presented by using a binary integer programming algorithm in order to maximize the surveillance coverage. Then, each camera view is decomposed into regions based on the Histograms of Color Optical Flow (HCOF), according to the spatial-temporal distribution of activity patterns observed in a training set of video sequences. We conduct experiments by using hours of video sequences captured at an office building with seven camera views, all of which are sparse scenes with complex activities. The results of real scene experiment show that the features of histograms of color optic flow offer important contextual information for spatial and temporal topology inference of a camera network. Hongguang Zhang, Jianzhu Cui, Peng Wang, and Shibao Zheng Copyright © 2014 Hongguang Zhang et al. All rights reserved.