Journal of Electrical and Computer Engineering http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2014 , Hindawi Publishing Corporation . 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. Performance Driven Six-Port Receiver and Its Advantages over Low-IF Receiver Architecture Sun, 23 Feb 2014 09:10:52 +0000 http://www.hindawi.com/journals/jece/2014/198120/ This paper provides an extensive analysis of the performance of a six-port based direct conversion receiver (SPR) in terms of signal quality, dynamic range, noise figure, ports matching, isolation, bandwidth, and cost. Calibration technique using multimemory polynomials has been adopted in order to improve the signal quality of the six-port receiver. The performances of the calibrated receiver are then compared with the performances of a commercially available I-Q demodulator used as a low-IF receiver. The main advantages and disadvantages of the SPR compared to the low-IF receiver are highlighted. The major advantages of the SPR come in terms of its available input frequency bandwidth and the low power requirement. The SPR system requires no external bias supply but suffers in terms of the available conversion gain. A better port matching of the SPR can be guaranteed over a wide frequency bandwidth, which mixer based receiver systems lack. The main component limiting the performance of a SPR is the diode detector. A faster and a better diode detector will alleviate some of the problems highlighted in this paper. The SPR system is calibratable and its error-vector-magnitude performance can be made better than the I-Q demodulator used as a low-IF receiver. Abul Hasan and Mohamed Helaoui Copyright © 2014 Abul Hasan and Mohamed Helaoui. All rights reserved. Performance of 2–3.6 GHz Five-Port/Three-Phase Demodulators with Baseband Analog Regeneration Circuit in Direct-Conversion Receivers Thu, 20 Feb 2014 09:19:59 +0000 http://www.hindawi.com/journals/jece/2014/631867/ A comparison between performance of a five-port demodulator (FPD) and a three-phase demodulator (TPD) with both architectures connected to a so-called baseband regeneration circuit is carried out. In order to compare these two receivers to a classical architecture, the performance of an demodulator (IQD) is also presented. Measured results show the superiority of TPD and IQD over FPD in terms of residual DC offsets and 2nd order intermodulation distortion (IMD2) products, noise figure (NF), and sensitivity due to the use of active balanced mixers instead of diode power detectors. Lastly, demodulation of three noncontiguous RF carriers shows the stronger potential of the three-phase demodulator (TPD) for applications in future long term evolution-advanced (LTE-A) receivers through EVM and constellation diagram measurements. Kaissoine Abdou, Antoine Khy, Kais Mabrouk, and Bernard Huyart Copyright © 2014 Kaissoine Abdou et al. All rights reserved. 4kUHD H264 Wireless Live Video Streaming Using CUDA Sun, 16 Feb 2014 11:03:02 +0000 http://www.hindawi.com/journals/jece/2014/183716/ Ultrahigh definition video streaming has been explored in recent years. Most recently the possibility of 4kUHD video streaming over wireless 802.11n was presented, using preencoded video. Live encoding for streaming using x264 has proven to be very slow. The use of parallel encoding has been explored to speed up the process using CUDA. However there hasnot been a parallel implementation for video streaming. We therefore present for the first time a novel implementation of 4kUHD live encoding for streaming over a wireless network at low bitrate indoors, using CUDA for parallel H264 encoding. Our experimental results are used to verify our claim. A. O. Adeyemi-Ejeye and S. Walker Copyright © 2014 A. O. Adeyemi-Ejeye and S. Walker. All rights reserved. Vehicle Tracking Algorithm Based on Observation Feedback and Block Symmetry Particle Filter Thu, 13 Feb 2014 16:03:06 +0000 http://www.hindawi.com/journals/jece/2014/520342/ This paper proposes a novel particle filter algorithm for vehicle tracking, which feeds observation information back to state model and integrates block symmetry into observation model. In view of the proposal distribution in traditional particle filter without considering the observation data, a new state transition model which takes the observation into account is presented, so that the allocation of particles is more familiar with the posterior distribution. To track the vehicles in background with similar colors or under partial occlusion, block symmetry is proposed and introduced into the observation model. Experimental results show that the proposed algorithm can improve the accuracy and robustness of vehicle tracking compared with traditional particle filter and Kernel Particle Filter. Yanshuang Hao, Yixin Yin, and Jinhui Lan Copyright © 2014 Yanshuang Hao et al. All rights reserved. Near-Threshold Computing and Minimum Supply Voltage of Single-Rail MCML Circuits Wed, 12 Feb 2014 09:13:27 +0000 http://www.hindawi.com/journals/jece/2014/836019/ In high-speed applications, MOS current mode logic (MCML) is a good alternative. Scaling down supply voltage of the MCML circuits can achieve low power-delay product (PDP). However, the current almost all MCML circuits are realized with dual-rail scheme, where the NMOS configuration in series limits the minimum supply voltage. In this paper, single-rail MCML (SRMCML) circuits are described, which can avoid the devices configuration in series, since their logic evaluation block can be realized by only using MOS devices in parallel. The relationship between the minimum supply voltage of the SRMCML circuits and the model parameters of MOS transistors is derived, so that the minimum supply voltage can be estimated before circuit designs. An MCML dynamic flop-flop based on SRMCML is also proposed. The optimization algorithm for near-threshold sequential circuits is presented. A near-threshold SRMCML mode-10 counter based on the optimization algorithm is verified. Scaling down the supply voltage of the SRMCML circuits is also investigated. The power dissipation, delay, and power-delay products of these circuits are carried out. The results show that the near-threshold SRMCML circuits can obtain low delay and small power-delay product. Ruiping Cao and Jianping Hu Copyright © 2014 Ruiping Cao and Jianping Hu. All rights reserved. Design of Information Acquisition and Control System for the Exoskeleton Robot Tue, 11 Feb 2014 12:18:38 +0000 http://www.hindawi.com/journals/jece/2014/309814/ This paper puts forward an information acquisition and control system for the exoskeleton robot, which can collect movement and location information of the robot timely through a variety of sensors. The information is preprocessed by the microcontroller firstly and then transmitted to the host computer for data analysis and processing by ZigBee wireless transmission module to analyze the movement intention of human by virtue of the monitoring software on the host computer. To achieve assistance, the motor drive will be controlled by the robot through CAN bus, and the robot can effectively analyze human’s intention and monitor the operation status of the assisted robot in practical applications, finally enhancing the body's walking ability. Huan Gou, Jialiu Wang, Hongfang Wu, Chao Wang, Lei Yan, and Jiang Xiao Copyright © 2014 Huan Gou et al. All rights reserved. Applying the Analog Configurability Test Approach in a Wireless Sensor Network Application Tue, 11 Feb 2014 08:57:15 +0000 http://www.hindawi.com/journals/jece/2014/309193/ This work addresses the application of the analog configurability test (ACT) approach for an embedded analog configurable circuit (EACC), composed of operational amplifiers and interconnection resources that are embedded in the MSP430xG461x microcontrollers family. This test strategy is particularly useful for in-field application requiring reliability, safe operation, or fault tolerance characteristics. Our test proposal consists of programming a reduced set of available configurations for the EACC and testing its functionality by measuring only a few key parameters. The processor executes an embedded test routine that sequentially programs selected configurations, sets the test stimulus, acquires data from the internal ADC, and performs required calculations. The test approach is experimentally evaluated using an embedded system-based real application board. Our experimental results show very good repeatability, with very low errors. These results show that the ACT proposed here is useful for testing the functionality of the circuit under test in a real application context by using a simple strategy at a very low cost. Agustín Laprovitta, Gabriela Peretti, and Eduardo Romero Copyright © 2014 Agustín Laprovitta et al. All rights reserved. CUSUM-Based Intrusion Detection Mechanism for Wireless Sensor Networks Tue, 11 Feb 2014 00:00:00 +0000 http://www.hindawi.com/journals/jece/2014/245938/ The nature of wireless sensor networks (WSNs) makes them very vulnerable to adversary's malicious attacks. Therefore, network security is an important issue to WSNs. Due to the constraints of WSN, intrusion detection in WSNs is a challengeable task. In this paper, we present a novel intrusion detection mechanism for WSNs, which is composed of a secure data communication algorithm and an intrusion detection algorithm. The major contribution of this paper is that we propose an original secure mechanism to defend WSNs against malicious attacks by using the information generated during data communication. The approach is able to protect the data communication in a WSN even if some sensor nodes are compromised by adversary. The proposed approach is easy to be implemented and performed in resource-constrained WSN. We also evaluate the proposed approach by a simulation experiment and analyze the simulation results in detail. Bishan Ying Copyright © 2014 Bishan Ying. All rights reserved. Crowd Event Perception Based on Spatiotemporal Weber Field Tue, 28 Jan 2014 11:14:20 +0000 http://www.hindawi.com/journals/jece/2014/719810/ Over the past decade, a wide attention has been paid to the crowd control and management in intelligent video surveillance area. Among the tasks of automatic video-based crowd management, crowd motion modeling is recognized as one of the most critical components, since it lays a crucial foundation for numerous subsequent analyses. However, it still encounters many unsolved challenges due to occlusions among pedestrians, complicated motion patterns in crowded scenarios, and so forth. Addressing these issues, we propose a novel spatiotemporal Weber field, which integrates both appearance characteristics and stimulus of crowd motion patterns, to recognize the large-scale crowd event. On the one hand, crowd motion is recognized as variations of spatiotemporal signal, and we then measure the variation based on Weber law. The result is referred to as spatiotemporal Weber variation feature. On the other hand, motivated by the achievements in crowd dynamics that crowd motion has a close relationship with interaction force, we propose a spatiotemporal Weber force feature to exploit the stimulus of crowd behaviors. Finally, we utilize the latent Dirichlet allocation model to establish the relationship between crowd events and crowd motion patterns. Experiments on PETS2009 and UMN databases demonstrate that our proposed method outperforms the previous methods for the large-scale crowd behavior perception. Zhou Su, Hua Wei, and Sha Wei Copyright © 2014 Zhou Su et al. All rights reserved. Performance Analysis of a Six-Port Receiver in a WCDMA Communication System including a Multipath Fading Channel Thu, 23 Jan 2014 08:54:10 +0000 http://www.hindawi.com/journals/jece/2014/198261/ Third generation communication systems require receivers with wide bandwidth of operation to support high transmission rates and are also reconfigurable to support various communication standards with different frequency bands. An ideal software defined radio (SDR) will be the absolute answer to this requirement but it is not achievable with the current level of technology. This paper proposes the use of a six-port receiver (SPR) front-end (FE) in a WCDMA communication system. A WCDMA end-to-end physical layer MATLAB demo which includes a multipath channel distortion block is used to determine the viability of the six-port based receiver. The WCDMA signal after passing through a multipath channel is received using a constructed SPR FE. The baseband signal is then calibrated and corrected in MATLAB. The six-port receiver performance is measured in terms of bit error rate (BER). The signal-to-noise ratio (SNR) of the transmitted data is varied and the BER profile of the communication system is plotted. The effect of the multipath fading on the receiver performance and the accuracy of the calibration algorithm are obtained by comparing two different measured BER curves for different calibration techniques to the simulated BER curve of an ideal receiver. A. O. Olopade and M. Helaoui Copyright © 2014 A. O. Olopade and M. Helaoui. All rights reserved. Advances in Radar Technologies Thu, 09 Jan 2014 08:15:24 +0000 http://www.hindawi.com/journals/jece/2014/818369/ Sandra Costanzo, Alvaro Rocha, and Marcelo Sampaio de Alencar Copyright © 2014 Sandra Costanzo et al. All rights reserved. Six-Port-Based Architecture for Phase Noise Measurement in the UWB Band Thu, 02 Jan 2014 13:16:41 +0000 http://www.hindawi.com/journals/jece/2014/646738/ A six-port-based frequency discriminator for phase noise measurement is proposed. This circuit makes use of a delay line discriminator configuration, thus not requiring reference oscillator. Furthermore, the use of a six-port network allows an extremely simple and completely passive solution well suited for low power oscillator measurement. A detailed study of the architecture is performed including the system noise sources. Besides, a prototype of the proposed six-port based delay line frequency discriminator is evaluated. Phase noise measurements of a commercial RF VCO are performed and compared with the results obtained with commercial metrology equipment with good agreement. J. M. Ávila-Ruiz, A. Moscoso-Mártir, E. Durán-Valdeiglesias, L. Moreno-Pozas, J. de-Oliva-Rubio, and I. Molina-Fernández Copyright © 2014 J. M. Ávila-Ruiz et al. All rights reserved. Online Detection of Abnormal Events in Video Streams Tue, 24 Dec 2013 15:02:02 +0000 http://www.hindawi.com/journals/jece/2013/837275/ We propose an algorithm to handle the problem of detecting abnormal events, which is a challenging but important subject in video surveillance. The algorithm consists of an image descriptor and online nonlinear classification method. We introduce the covariance matrix of the optical flow and image intensity as a descriptor encoding moving information. The nonlinear online support vector machine (SVM) firstly learns a limited set of the training frames to provide a basic reference model then updates the model and detects abnormal events in the current frame. We finally apply the method to detect abnormal events on a benchmark video surveillance dataset to demonstrate the effectiveness of the proposed technique. Tian Wang, Jie Chen, and Hichem Snoussi Copyright © 2013 Tian Wang et al. All rights reserved. A Compact, Versatile Six-Port Radar Module for Industrial and Medical Applications Thu, 12 Dec 2013 10:05:17 +0000 http://www.hindawi.com/journals/jece/2013/382913/ The Six-port receiver has been intensively investigated in the last decade to be implemented as an alternative radar architecture. Plenty of current scientific publications demonstrate the effectiveness and versatility of the Six-port radar for special industrial, automotive, and medical applications, ranging from accurate contactless vibration analysis, through automotive radar calibration, to remote breath and heartbeat monitoring. Its highlights, such as excellent phase discrimination, trivial signal processing, low circuit complexity, and cost, have lately drawn the attention of companies working with radar technology. A joint project involving the University of Erlangen-Nuremberg and InnoSenT GmbH (Innovative Sensor Technology) led to the development of a highly accurate, compact, and versatile Six-port radar module aiming at a reliable high-integration of all subcomponents such as antenna, Six-port front-end, baseband circuitry, and digital signal processing in one single package. Innovative aspects in the RF front-end design as well as in the integration strategy are hereby presented, together with a system overview and measurement results. Sarah Linz, Gabor Vinci, Sebastian Mann, Stefan Lindner, Francesco Barbon, R. Weigel, and Alexander Koelpin Copyright © 2013 Sarah Linz et al. All rights reserved. Evaluation of Cover and Reflector in Receiver Antennas for SM-MIMO Wireless Communications Tue, 03 Dec 2013 09:06:37 +0000 http://www.hindawi.com/journals/jece/2013/123827/ Spatial multiplexing multiple-input multiple-output (SM-MIMO) is effective in increasing communication throughput. However, performance degradation occurs in poor multipath and line-of-sight (LOS) channels due to the high spatial correlation. This paper presents the evaluation of cover and reflector in receiver antennas to overcome the performance degradation in MIMO LOS channels. We measured the characteristics of packet error rate (PER), signal-to-noise ratio (SNR), spatial correlation coefficient, and received power ratio in farm, groove, passage, and corner environments. The farm environment degraded communication performance due to the high spatial correlation coefficient. Following the measurement results, we fabricated cover and reflector in receiver antennas to decrease the high spatial correlation and confirmed the improvement of communication performance. Shingo Yoshizawa and Yoshikazu Miyanaga Copyright © 2013 Shingo Yoshizawa and Yoshikazu Miyanaga. All rights reserved. Analytical Review of Data Visualization Methods in Application to Big Data Tue, 26 Nov 2013 14:28:28 +0000 http://www.hindawi.com/journals/jece/2013/969458/ This paper describes the term Big Data in aspects of data representation and visualization. There are some specific problems in Big Data visualization, so there are definitions for these problems and a set of approaches to avoid them. Also, we make a review of existing methods for data visualization in application to Big Data and taking into account the described problems. Summarizing the result, we have provided a classification of visualization methods in application to Big Data. Evgeniy Yur’evich Gorodov and Vasiliy Vasil’evich Gubarev Copyright © 2013 Evgeniy Yur’evich Gorodov and Vasiliy Vasil’evich Gubarev. All rights reserved. Complete Characterization of Novel MHMICs for V-Band Communication Systems Mon, 18 Nov 2013 11:39:45 +0000 http://www.hindawi.com/journals/jece/2013/686708/ This paper presents the characterization results of several new passive millimeter wave circuits integrated on very thin ceramic substrate. The work is focused on the design and characterization of a novel rounded Wilkinson power divider, a 90° hybrid coupler, a rat-race coupler, and a novel six-port (multiport) circuit. Measurements show the wideband characteristics, allowing therefore their use for multi-Gb/s V-band wireless communication systems. C. Hannachi, D. Hammou, T. Djerafi, Z. Ouardirhi, and S. O. Tatu Copyright © 2013 C. Hannachi et al. All rights reserved. Enhancement of Background Subtraction Techniques Using a Second Derivative in Gradient Direction Filter Mon, 11 Nov 2013 13:27:57 +0000 http://www.hindawi.com/journals/jece/2013/598708/ A new approach was proposed to improve traditional background subtraction (BGS) techniques by integrating a gradient-based edge detector called a second derivative in gradient direction (SDGD) filter with the BGS output. The four fundamental BGS techniques, namely, frame difference (FD), approximate median (AM), running average (RA), and running Gaussian average (RGA), showed imperfect foreground pixels generated specifically at the boundary. The pixel intensity was lesser than the preset threshold value, and the blob size was smaller. The SDGD filter was introduced to enhance edge detection upon the completion of each basic BGS technique as well as to complement the missing pixels. The results proved that fusing the SDGD filter with each elementary BGS increased segmentation performance and suited postrecording video applications. Evidently, the analysis using F-score and average accuracy percentage proved this, and, as such, it can be concluded that this new hybrid BGS technique improved upon existing techniques. Farah Yasmin Abdul Rahman, Aini Hussain, Wan Mimi Diyana Wan Zaki, Halimah Badioze Zaman, and Nooritawati Md Tahir Copyright © 2013 Farah Yasmin Abdul Rahman et al. All rights reserved.