International Journal of Electrical, Electronic and Communication Sciences

Performance Analysis of an Island Power System Including Wind Turbines Operating under Random Wind Speed

Year: 2013 Volume: 7 Issue: 7 868 - 878 Pages

Abstract: With continuous rise of oil price, how to develop alternative energy source has become a hot topic around the world. This study discussed the dynamic characteristics of an island power system operating under random wind speed lower than nominal wind speeds of wind turbines. The system primarily consists of three diesel engine power generation systems, three constant-speed variable-pitch wind turbines, a small hydraulic induction generation system, and lumped static loads. Detailed models based on Matlab/Simulink were developed to cater for the dynamic behavior of the system. The results suggested this island power system can operate stably in this operational mode. This study can serve as an important reference for planning, operation, and further expansion of island power systems.

Design of Electromagnetic Drive Module for Micro-gyroscope

Year: 2010 Volume: 4 Issue: 10 1505 - 1510 Pages

Abstract: For micro-gyroscopes, the angular rate detection components have to oscillate forwards and backwards alternatively. An innovative design of micro-electromagnetic drive module is proposed to make a Π-type disc reciprocally and efficiently rotate within a certain of angular interval. Twelve Electromagnetic poles enclosing the thin disc are designed to provide the magnetic drive power. Isotropic etching technique is employed to fabricate the high-aspect-ratio trench, so that the contact angle of wire against trench can be increased and the potential defect of cavities and pores within the wire can be prevented. On the other hand, a Π-type thin disc is designed to conduct the pitch motion as an angular excitation, in addition to spinning, is exerted on the gyroscope. The efficacy of the micro-magnetic drive module is verified by the commercial software, Ansoft Maxewll. In comparison with the conventional planar windings in micro-scale systems, the magnetic drive force is increased by 150%.

Normalized Cumulative Spectral Distribution in Music

Year: 2008 Volume: 2 Issue: 5 851 - 855 Pages

Abstract: As the remedy used music becomes active and meditation effect through the music is verified, people take a growing interest about psychological balance or remedy given by music. From traditional studies, it is verified that the music of which spectral envelop varies approximately as 1/f (f is frequency) down to a frequency of low frequency bandwidth gives psychological balance. In this paper, we researched signal properties of music which gives psychological balance. In order to find this, we derived the property from voice. Music composed by voice shows large value in NCSD. We confirmed the degree of deference between music by curvature of normalized cumulative spectral distribution. In the music that gives psychological balance, the curvature shows high value, otherwise, the curvature shows low value.

Keywords:
Cognitive Psychology
Normalized Cumulative Spectral Distribution
Curvature.

An Innovative Wireless Sensor Network Protocol Implementation using a Hybrid FPGA Technology

Year: 2011 Volume: 5 Issue: 5 657 - 660 Pages

Abstract: Traditional development of wireless sensor network mote is generally based on SoC1 platform. Such method of development faces three main drawbacks: lack of flexibility in terms of development due to low resource and rigid architecture of SoC; low capability of evolution and portability versus performance if specific micro-controller architecture features are used; and the rapid obsolescence of micro-controller comparing to the long lifetime of power plants or any industrial installations. To overcome these drawbacks, we have explored a new approach of development of wireless sensor network mote using a hybrid FPGA technology. The application of such approach is illustrated through the implementation of an innovative wireless sensor network protocol called OCARI.

Content and Resources based Mobile and Wireless Video Transcoding

Year: 2008 Volume: 2 Issue: 4 639 - 644 Pages

Authors:
Ashraf M. A. Ahmad

Abstract: Delivering streaming video over wireless is an important component of many interactive multimedia applications running on personal wireless handset devices. Such personal devices have to be inexpensive, compact, and lightweight. But wireless channels have a high channel bit error rate and limited bandwidth. Delay variation of packets due to network congestion and the high bit error rate greatly degrades the quality of video at the handheld device. Therefore, mobile access to multimedia contents requires video transcoding functionality at the edge of the mobile network for interworking with heterogeneous networks and services. Therefore, to guarantee quality of service (QoS) delivered to the mobile user, a robust and efficient transcoding scheme should be deployed in mobile multimedia transporting network. Hence, this paper examines the challenges and limitations that the video transcoding schemes in mobile multimedia transporting network face. Then handheld resources, network conditions and content based mobile and wireless video transcoding is proposed to provide high QoS applications. Exceptional performance is demonstrated in the experiment results. These experiments were designed to verify and prove the robustness of the proposed approach. Extensive experiments have been conducted, and the results of various video clips with different bit rate and frame rate have been provided.

Intelligibility of Cued Speech in Video

Year: 2011 Volume: 5 Issue: 7 837 - 841 Pages

Abstract: This paper discusses the cued speech recognition methods in videoconference. Cued speech is a specific gesture language that is used for communication between deaf people. We define the criteria for sentence intelligibility according to answers of testing subjects (deaf people). In our tests we use 30 sample videos coded by H.264 codec with various bit-rates and various speed of cued speech. Additionally, we define the criteria for consonant sign recognizability in single-handed finger alphabet (dactyl) analogically to acoustics. We use another 12 sample videos coded by H.264 codec with various bit-rates in four different video formats. To interpret the results we apply the standard scale for subjective video quality evaluation and the percentual evaluation of intelligibility as in acoustics. From the results we construct the minimum coded bit-rate recommendations for every spatial resolution.

An ICA Algorithm for Separation of Convolutive Mixture of Speech Signals

Year: 2008 Volume: 2 Issue: 11 2549 - 2559 Pages

Abstract: This paper describes Independent Component Analysis (ICA) based fixed-point algorithm for the blind separation of the convolutive mixture of speech, picked-up by a linear microphone array. The proposed algorithm extracts independent sources by non- Gaussianizing the Time-Frequency Series of Speech (TFSS) in a deflationary way. The degree of non-Gaussianization is measured by negentropy. The relative performances of algorithm under random initialization and Null beamformer (NBF) based initialization are studied. It has been found that an NBF based initial value gives speedy convergence as well as better separation performance

Implementing a Prototype System for Power Facility Management using RFID/WSN

Year: 2008 Volume: 2 Issue: 4 633 - 638 Pages

Abstract: Firstly, research and development on RFID focuses on manufacturing and retail sectors, because it can improve supply chain efficiency. But, now a variety of field is considered the next research area for Radio Frequency Identification (RFID). Although RFID is infancy, RFID technology has great potential in power industry to significantly reduce cost, and improve quality of power supply. To complement the limitation of RFID, we adopt the WSN (Wireless Sensor Network) technology. However, relevant experience is limited, the challenge will be to derive requirement from business practice and to determine whether it is possible or not. To explore this issue, we conduct a case study on implementing power facility management system using RFID/WSN in Korea Electric Power Corporation (KEPCO). In this paper we describe requirement from power industry. And we introduce design and implementation of the test bed.

Coupled Multifield Analysis of Piezoelectrically Actuated Microfluidic Device for Transdermal Drug Delivery Applications

Year: 2010 Volume: 4 Issue: 2 296 - 300 Pages

Abstract: In this paper, design, fabrication and coupled multifield analysis of hollow out-of-plane silicon microneedle array with piezoelectrically actuated microfluidic device for transdermal drug delivery (TDD) applications is presented. The fabrication process of silicon microneedle array is first done by series of combined isotropic and anisotropic etching processes using inductively coupled plasma (ICP) etching technology. Then coupled multifield analysis of MEMS based piezoelectrically actuated device with integrated 2×2 silicon microneedle array is presented. To predict the stress distribution and model fluid flow in coupled field analysis, finite element (FE) and computational fluid dynamic (CFD) analysis using ANSYS rather than analytical systems has been performed. Static analysis and transient CFD analysis were performed to predict the fluid flow through the microneedle array. The inlet pressure from 10 kPa to 150 kPa was considered for static CFD analysis. In the lumen region fluid flow rate 3.2946 μL/min is obtained at 150 V for 2×2 microneedle array. In the present study the authors have performed simulation of structural, piezoelectric and CFD analysis on three dimensional model of the piezoelectrically actuated mcirofluidic device integrated with 2×2 microneedle array.

Distributed Estimation Using an Improved Incremental Distributed LMS Algorithm

Year: 2009 Volume: 3 Issue: 11 2056 - 2060 Pages

Abstract: In this paper we consider the problem of distributed adaptive estimation in wireless sensor networks for two different observation noise conditions. In the first case, we assume that there are some sensors with high observation noise variance (noisy sensors) in the network. In the second case, different variance for observation noise is assumed among the sensors which is more close to real scenario. In both cases, an initial estimate of each sensor-s observation noise is obtained. For the first case, we show that when there are such sensors in the network, the performance of conventional distributed adaptive estimation algorithms such as incremental distributed least mean square (IDLMS) algorithm drastically decreases. In addition, detecting and ignoring these sensors leads to a better performance in a sense of estimation. In the next step, we propose a simple algorithm to detect theses noisy sensors and modify the IDLMS algorithm to deal with noisy sensors. For the second case, we propose a new algorithm in which the step-size parameter is adjusted for each sensor according to its observation noise variance. As the simulation results show, the proposed methods outperforms the IDLMS algorithm in the same condition.

Load Flow Analysis: An Overview

Year: 2012 Volume: 6 Issue: 3 310 - 315 Pages

Abstract: The load flow study in a power system constitutes a study of paramount importance. The study reveals the electrical performance and power flows (real and reactive) for specified condition when the system is operating under steady state. This paper gives an overview of different techniques used for load flow study under different specified conditions.

Wormhole Attack Detection in Wireless Sensor Networks

Year: 2008 Volume: 2 Issue: 10 2272 - 2277 Pages

Abstract: The nature of wireless ad hoc and sensor networks make them very attractive to attackers. One of the most popular and serious attacks in wireless ad hoc networks is wormhole attack and most proposed protocols to defend against this attack used positioning devices, synchronized clocks, or directional antennas. This paper analyzes the nature of wormhole attack and existing methods of defending mechanism and then proposes round trip time (RTT) and neighbor numbers based wormhole detection mechanism. The consideration of proposed mechanism is the RTT between two successive nodes and those nodes- neighbor number which is needed to compare those values of other successive nodes. The identification of wormhole attacks is based on the two faces. The first consideration is that the transmission time between two wormhole attack affected nodes is considerable higher than that between two normal neighbor nodes. The second detection mechanism is based on the fact that by introducing new links into the network, the adversary increases the number of neighbors of the nodes within its radius. This system does not require any specific hardware, has good performance and little overhead and also does not consume extra energy. The proposed system is designed in ad hoc on-demand distance vector (AODV) routing protocol and analysis and simulations of the proposed system are performed in network simulator (ns-2).

Analysis of Bit Error Rate Improvement in MFSK Communication Link

Year: 2008 Volume: 2 Issue: 9 1950 - 1954 Pages

Abstract: Data rate, tolerable bit error rate or frame error rate and range & coverage are the key performance requirement of a communication link. In this paper performance of MFSK link is analyzed in terms of bit error rate, number of errors and total number of data processed. In the communication link model proposed, which is implemented using MATLAB block set, an improvement in BER is observed. Different parameters which effects and enables to keep BER low in M-ary communication system are also identified.

Shape Error Concealment for Shape Independent Transform Coding

Year: 2011 Volume: 5 Issue: 7 833 - 836 Pages

Abstract: Arbitrarily shaped video objects are an important concept in modern video coding methods. The techniques presently used are not based on image elements but rather video objects having an arbitrary shape. In this paper, spatial shape error concealment techniques to be used for object-based image in error-prone environments are proposed. We consider a geometric shape representation consisting of the object boundary, which can be extracted from the α-plane. Three different approaches are used to replace a missing boundary segment: Bézier interpolation, Bézier approximation and NURBS approximation. Experimental results on object shape with different concealment difficulty demonstrate the performance of the proposed methods. Comparisons with proposed methods are also presented.

Design of Variable Fractional-Delay FIR Differentiators

Year: 2009 Volume: 3 Issue: 6 1325 - 1329 Pages

Abstract: In this paper, the least-squares design of variable fractional-delay (VFD) finite impulse response (FIR) digital differentiators is proposed. The used transfer function is formulated so that Farrow structure can be applied to realize the designed system. Also, the symmetric characteristics of filter coefficients are derived, which leads to the complexity reduction by saving almost a half of the number of coefficients. Moreover, all the elements of related vectors or matrices for the optimal process can be represented in closed forms, which make the design easier. Design example is also presented to illustrate the effectiveness of the proposed method.

Access Control System: Monitoring Tool for Fiber to the Home Passive Optical Network

Year: 2009 Volume: 3 Issue: 2 268 - 273 Pages

Abstract: An optical fault monitoring in FTTH-PON using ACS is demonstrated. This device can achieve real-time fault monitoring for protection feeder fiber. In addition, the ACS can distinguish optical fiber fault from the transmission services to other customers in the FTTH-PON. It is essential to use a wavelength different from the triple-play services operating wavelengths for failure detection. ACS is using the operating wavelength 1625 nm for monitoring and failure detection control. Our solution works on a standard local area network (LAN) using a specially designed hardware interfaced with a microcontroller integrated Ethernet.

A Power-Controlled Scheduling Scheme Using a Directional Antenna in Smart Home

Year: 2012 Volume: 6 Issue: 11 1318 - 1322 Pages

Abstract: This paper proposes a power-controlled scheduling scheme for devices using a directional antenna in smart home. In the case of the home network using directional antenna, devices can concurrently transmit data in the same frequency band. Accordingly, the throughput increases compared to that of devices using omni-directional antenna in proportional to the number of concurrent transmissions. Also, the number of concurrent transmissions depends on the beamwidth of antenna, the number of devices operating in the network , transmission power, interference and so on. In particular, the less transmission power is used, the more concurrent transmissions occur due to small transmission range. In this paper, we considered sub-optimal scheduling scheme for throughput maximization and power consumption minimization. In the scheme, each device is equipped with a directional antenna. Various beamwidths, path loss components, and antenna radiation efficiencies are considered. Numerical results show that the proposed schemes outperform the scheduling scheme using directional antennas without power control.

Peer-to-Peer Epidemic Algorithms for Reliable Multicasting in Ad Hoc Networks

Year: 2007 Volume: 1 Issue: 3 474 - 478 Pages

Abstract: Characteristics of ad hoc networks and even their existence depend on the nodes forming them. Thus, services and applications designed for ad hoc networks should adapt to this dynamic and distributed environment. In particular, multicast algorithms having reliability and scalability requirements should abstain from centralized approaches. We aspire to define a reliable and scalable multicast protocol for ad hoc networks. Our target is to utilize epidemic techniques for this purpose. In this paper, we present a brief survey of epidemic algorithms for reliable multicasting in ad hoc networks, and describe formulations and analytical results for simple epidemics. Then, P2P anti-entropy algorithm for content distribution and our prototype simulation model are described together with our initial results demonstrating the behavior of the algorithm.

Multiclass Support Vector Machines for Environmental Sounds Classification Using log-Gabor Filters

Year: 2012 Volume: 6 Issue: 8 813 - 817 Pages

Authors:
S. Souli
Z. Lachiri

Abstract: In this paper we propose a robust environmental sound classification approach, based on spectrograms features driven from log-Gabor filters. This approach includes two methods. In the first methods, the spectrograms are passed through an appropriate log-Gabor filter banks and the outputs are averaged and underwent an optimal feature selection procedure based on a mutual information criteria. The second method uses the same steps but applied only to three patches extracted from each spectrogram. To investigate the accuracy of the proposed methods, we conduct experiments using a large database containing 10 environmental sound classes. The classification results based on Multiclass Support Vector Machines show that the second method is the most efficient with an average classification accuracy of 89.62 %.

Microwave Imaging by Application of Information Theory Criteria in MUSIC Algorithm

Year: 2014 Volume: 8 Issue: 8 1265 - 1269 Pages

Authors:
M. Pourahmadi

Abstract: The performance of time-reversal MUSIC algorithm will be dramatically degrades in presence of strong noise and multiple scattering (i.e. when scatterers are close to each other). This is due to error in determining the number of scatterers. The present paper provides a new approach to alleviate such a problem using an information theoretic criterion referred as minimum description length (MDL). The merits of the novel approach are confirmed by the numerical examples. The results indicate the time-reversal MUSIC yields accurate estimate of the target locations with considerable noise and multiple scattering in the received signals.