Engineering Commons^™

Ict For Poverty Alleviation In Pacific Island Nations: Study Of Icts4d In Fiji, Deogratias Harorimana, Opeti Rokotuinivono, Emali Sewale, Fane Salaiwai, Marica Naulu, Evangelin Roy

Dr Deogratias Harorimana

ICT for Poverty Alleviation in Pacific Island Nations: Study of ICTs4D in Fiji There has been a vague and little knowledge on the role or potential of Information and Communications Technologies (ICTs) in relation to addressing poverty in Fiji. This may be probably due to the newness of the technology in the South Pacific Region as a whole but also probably due to the fact that only 9.7% of the current Fiji 931,000 populations are internet users (ITC Figures 2011). This paper reports on finding how ICTs is contributing towards poverty alleviation in Fiji. On the basis of reviewed best …

Technical Comparison Of Harmonic Mitigation Techniques For Industrial Electrical Power Systems, Almoataz Abdelaziz

Almoataz Youssef Abdelaziz

Power system harmonics cause many problems like equipment failures, malfunctions and plant shutdowns. Accordingly, mitigation of these harmonics is considered an important target especially for the industrial applications where any short downtime period may lead to great economic losses. There are at least ten different mitigation techniques to choose from, each with specific technical advantages and disadvantages. Comparative studies for the harmonic mitigation techniques in industrial electrical systems are rarely found in the literature even though they are strongly needed. This paper, almost for the first time, provides comprehensive technical comparisons between the various practical harmonics mitigation techniques in the …

Detection Of Line Outage In Transmission Networks Using Phasor Measurement Units Aided By Support Vector Machine Algorithms, Almoataz Youssef Abdelaziz

Almoataz Youssef Abdelaziz

Many protection applications are based upon the Phasor Measurement Units (PMUs) technology. Therefore, PMUs have been increasingly widespread throughout the power network, and there are several researches have been made to locate the PMUs for complete system observability. This paper introduces an important application of PMUs in power system protection which is the detection of single line outage. In addition, a detection of the out of service line is achieved depending on the variations of phase angles measured at the system buses where the PMUs are located. Hence, a protection scheme from unexpected overloading in the network that may lead …

Protection Schemes Based On Support Vector Machine For Thyristor Controlled Series Compensated Transmission Line, Almoataz Youssef Abdelaziz

Almoataz Youssef Abdelaziz

Recently, series compensation is widely used in transmission. However, this creates several problems to conventional protection approaches. This paper presents overcurrent and distance protection schemes, for fault classification in transmission lines with thyristor controlled series capacitor (TCSC) using support vector machine (SVM). The fault classification task is divided into four separate subtasks (SVMa, SVMb, SVMc and SVMg), where the state of each phase and ground is determined by an individual SVM. The polynomial kernel SVM is designed to provide the optimal classification conditions. Wide variations of load angle, fault inception angle, fault resistance and fault location have been carried out …

Phasor Measurement Units (Pmus) Based Fault Location Of Series Compensated Transmission Lines, Almoataz Youssef Abdelaziz

Almoataz Youssef Abdelaziz

Phasor Measurement Units (PMUs) have gained a great popularity in the field of control and wide area protection during the last decade. One of the major protection applications based on PMUs technology is to determine the fault location in a transmission line. Therefore, several researches have been developed in the field of fault location. Some of the researches are based on one-end measurements. But, a greater accuracy has been achieved on the basis of two-end measurements. Many researchers suggested only voltage measurements to avoid the current transformers (CT) errors. While, others suggested methods depend on both voltages and current measurements …

Optimal Pmu Placement For Complete Observability Using Heuristic Methods, Almoataz Youssef Abdelaziz

Almoataz Youssef Abdelaziz

An essential tool for power system monitoring is state estimation. Phasor Measurement Units (PMUs) can greatly improve the state estimation process. However, for state estimation, the PMUs should be placed appropriately in the network. The problem of optimal PMU placement for full observability is analyzed in this paper. The objective of the paper is to minimize the size of the PMU configuration while allowing full observability of the network. At first, an optimal measurement set is determined to achieve full power system observability with ignoring zero injection buses. Then, the derived schemes are modified to maintain the observability after considering …

Transient Security Classification Using Gene Expression Programming Algorithm, Almoataz Youssef Abdelaziz

Almoataz Youssef Abdelaziz

No abstract provided.

Electrical Tuning Of Magnetism In Fe₃O₄/Pzn–Pt Multiferroic Heterostructures Derived By Reactive Magnetron Sputtering, Ming Liu, Ogheneyunume Obi, Zhuhua Cai, Jing Lou, Guomin Yang, Katherine S. Ziemer, Nian X. Sun

Dr Guomin Yang

Strong magnetoelectric (ME) coupling was demonstrated in Fe₃O₄/PZN–PT (lead zinc niobate–lead titanate) multiferroic heterostructures obtained through a sputter deposition process. The dependence of the magnetic anisotropy on the electric field (E-field) is theoretically predicted and experimentally observed by ferromagnetic resonance spectroscopy. A large tunable in-plane magnetic anisotropy of up to 600 Oe, and tunable out-of-plane anisotropy of up to 400 Oe were observed in the Fe₃O₄/PZN–PT multiferroic heterostructures, corresponding to a large ME coefficient of 100 Oe cm/kV in plane and 68 Oe cm/kV out of plane, which match well with predicted results. In addition, the electric field manipulation of …

Tunable Miniaturized Rf Devices On Magneto-Dielectric Substrates With Enhanced Performance, Guomin Yang

Dr Guomin Yang

In this dissertation we have studied planar microstrip antennas and RF filters miniaturization and performance improvement with novel substrate, superstrate and hybrid substrate/superstrate structure. In particular, we have compared dielectric materials and magneto-dielectric materials, and used the magneto-dielectric materials to counteract the narrowing of bandwidth, and the impedance mismatch due to the use of high permittivity materials as antenna substrates. However, from materials perspective, it has been challenging to achieve self-biased magnetic materials for antenna substrate applications at frequencies>600 MHz range due to the well known Snoek limit. Magnetic thin films provide a unique opportunity for achieving self-biased magnetic …

Spectral-Efficiency Of Multi-Antenna Links In Ad-Hoc Networks With Limited Tx Csi, Siddhartan Govindasamy, Daniel Bliss, David Staelin

Siddhartan Govindasamy

An asymptotic expression is derived for the mean spectral efficiency of multi-antenna links randomly distributed on a plane in a uniform manner where transmitters (Tx) have Channel-State-Information (CSI) of the channels between themselves and their target receivers while receivers (Rx) have CSI between themselves and all transmitters. The mean per-link spectral efficiency in the network is found to increase if nodes transmit using a subset of their strongest channel modes instead of the link-optimal strategy of water-filling on all channel modes (Farrokhi et al.). For reasonable parameters, this system which requires limited Tx CSI, has approximately double the mean spectral …

Spectral Efficiency In Single-Hop Ad-Hoc Wireless Networks With Interference Using Adaptive Antenna Arrays, Siddhartan Govindasamy, Daniel Bliss, David Staelin

Siddhartan Govindasamy

Receivers with N antennas in single-hop, ad-hoc wireless networks with nodes randomly distributed on an infinite plane with uniform area density are studied. Transmitting nodes have single antennas and transmit simultaneously in the same frequency band with power P that decays with distance via the commonly-used inverse-polynomial model with path-loss-exponent (PLE) greater than 2. This model applies to shared spectrum systems where multiple links share the same frequency band. In the interference-limited regime, the average spectral efficiency of a representative link E[C] (b/s/Hz/link) is found to grow as log(N) and linearly with PLE, and its variance decays as 1/N. The …

Cdf Of The Spectral-Efficiency Of A Simple Distributed Channel Assignment Algorithm In Spatially Distributed Wireless Networks, Siddhartan Govindasamy, Raghu Rangan, Elena Koukina, Ashley Lloyd

Siddhartan Govindasamy

The Cumulative-Distribution-Function (CDF) of the spectral efficiency of links in spatially distributed networks with orthogonal channels and a simple channel assignment algorithm is presented for constant link-lengths and nearest-neighbor links. Transmitters are randomly distributed on the plane with uniform probability, and receivers are either randomly distributed or at hexagonal lattice sites. This result includes random channel assignments as a special case. The CDF is used to find the spectral efficiency for a given, small outage probability which is used to optimize the number of channels to maximize the spectral efficiency. The optimum number of channels represents the best trade off …

On The Spectral Efficiency Of Links With Multi-Antenna Receivers In Non-Homogenous Wireless Networks, Siddhartan Govindasamy, Daniel Bliss

Siddhartan Govindasamy

An asymptotic technique is developed to find the Signal-to-Interference-plus-Noise-Ratio (SINR) and spectral efficiency of a link with N receiver antennas in wireless networks with non-homogeneous distributions of nodes. It is found that with appropriate normalization, the SINR and spectral efficiency converge with probability 1 to asymptotic limits as N increases. This technique is applied to networks with power-law node intensities, which includes homogeneous networks as a special case, to find a simple approximation for the spectral efficiency. It is found that for receivers in dense clusters, the SINR grows with N at rates higher than that of homogeneous networks and …

The Performance Of Linear Multiple-Antenna Receivers With Interferes Distributed On A Plane, Siddhartan Govindasamy, Filip Antic, Daniel Bliss, David Staelin

Siddhartan Govindasamy

We find an asymptotic expression for the average signal to interference ratio (SIR) between a transmitter with a single isotropic antenna and a multi-antenna linear receiver in the presence of interferers with single isotropic transmit antennas distributed uniformly on an infinite plane. The channels are modeled as complex Gaussian random variables with average received power dependent on the distance separating nodes. We find that in large networks, the average SIR for a representative link depends primarily on the ratio of the number of receive antenna elements to the area density of interferers. Furthermore for our network model, the SIR grows …

Minimizing Hidden-Node Network Interference By Optimizing Siso And Mimo Spectral Efficiency, Daniel Bliss, Siddhartan Govindasamy

Siddhartan Govindasamy

In this paper, the optimal spectral efficiency (data rate divided by the message bandwidth) that minimizes the probability of causing disruptive interference for ad hoc wireless networks or cognitive radios is investigated. Two basic problem constraints are considered: a given message size, or fixed data rate. Implicitly, the trade being optimized is between longer transmit duration and wider bandwidth versus higher transmit power. Both single-input single-output (SISO) and multiple-input multiple-output (MIMO) links are considered. Here, a link optimizes its spectral efficiency to be a “good neighbor.” The probability of interference is characterized by the probability that the signal power received …

Linear Mmse Receivers For Random Cdma In Wireless Networks With Equal Transmit Powers, Siddhartan Govindasamy, David Staelin

Siddhartan Govindasamy

The performance of single-hop links in ad-hoc wireless systems using direct-sequence (DS) code-division-multiple-access (CDMA) with random signature sequences and linear minimum-mean-square-error (MMSE) receivers is investigated. Expressions for the average signal-to-interference-plus-noise-ratio (SINR) and spectral efficiency (b s^-1 Hz^-1 link^-1) were derived for a representative link in the presence of interferers distributed randomly on a plane with uniform area density p interferers m^-2. Nodes transmit with equal power P, which decays with distance r as r^-alpha. An expression for the optimum spreading factor given system parameters is also provided. It is found that for …

Asymptotic Spectral Efficiency Of Multiantenna Links In Wireless Networks With Limited Tx Csi, Siddhartan Govindasamy, Daniel Bliss, David Staelin

Siddhartan Govindasamy

An asymptotic technique is presented for finding the spectral efficiency of multiantenna links in spatially distributed wireless networks where transmitters have channel-state-information (CSI) corresponding to their target receiver. Transmitters are assumed to transmit independent data streams on a limited number of channel modes which limits the rank of transmit covariance matrices. An approximation for the spectral efficiency in the interference-limited regime as a function of link-length, interferer density, number of antennas per receiver and transmitter, number of transmit streams, and path-loss exponent is derived. It is found that targeted-receiver CSI, which can be acquired with low overhead in duplex systems …

Spectral Efficiency Of Wireless Networks With Multi-Antenna Base Stations And Spatially Distributed Nodes, Siddhartan Govindasamy, Daniel Bliss, David Staelin

Siddhartan Govindasamy

We analyze networks with wireless nodes distributed randomly in space, transmitting simultaneously in the same channel to their nearest base-stations using a simple power control algorithm. Base-stations are on a hexagonal grid and have N optimally-phased antennas. We derive the asymptotic mean upstream spectral efficiency(validated by simulation) as a function of N, wireless-node density, base-station separation, and path-loss-exponent which controls signal attenuation with distance. These results indicate that mean per-link spectralefficiency is constant if the number of receive antennas or density of base-stations is increased linearly withwireless node density. They also improve our understanding of systems like city-wide wireless Internet …

Power Electronics Enabled System Design And Power Management Control In Future Fuel Cell Vehicle, Lei Wang

Dr Lei Wang

Advanced vehicle technology including hybrid electric vehicles, plug-in hybrid electric vehicles, and fuel cell hybrid electric vehicles are attracting attention recently, as climate change and energy shortage become a more and more severe problem. Among all the options, fuel cell hybrid electric vehicles (FCHV) are considered to be next generation dominant technology because of its zero emission characteristic and other advantages.

While active research is continuously being pursued in the use of energy storage elements and power management strategies in fuel cell hybrid vehicle applications, the research reported so far in literature has limited guidance in real application. They consider …

Study Of The Cascaded Z-Source Inverter To Solve The Partial Shading For The Grid-Connected Pv System, Lei Wang

Dr Lei Wang

Recently there have been increasing interests in developing the renewable energy resources for the future energy need. Solar energy generation has shown its great potential to serve as a clean distributed energy source. While one drawback of the solar source is that when partial shading happens, which means the PV panels receive the non-uniform irradiation, the PV system output power would reduce depending on the partial shading scenario. Under this circumstance, the cascaded Z-source inverter for the grid-connected PV system is proposed to solve the partial shading problem. In order to demonstrate the proposed technology, the single stage Z-source inverter …

Novel Constructions Of Improved Square Complex Orthogonal Designs For Eight Transmit Antennas, Le Chung Tran, Tadeusz Wysocki, Jennifer Seberry, Alfred Mertins, Sarah Adams

Dr Le Chung Tran

Constructions of square, maximum rate complex orthogonal space-time block codes (CO STBCs) are well known, however codes constructed via the known methods include numerous zeros, which impede their practical implementation. By modifying the Williamson and Wallis-Whiteman arrays to apply to complex matrices, we propose two methods of construction of square, order-4n CO STBCs from square, order-n codes which satisfy certain properties. Applying the proposed methods, we construct square, maximum rate, order-8 CO STBCs with no zeros, such that the transmitted symbols are equally dispersed through transmit antennas. Those codes, referred to as the improved square CO STBCs, have the advantages …

Scaling Bayesian Network Parameter Learning With Expectation Maximization Using Mapreduce, Erik B. Reed, Ole J. Mengshoel

Ole J Mengshoel

Mapreduce For Bayesian Network Parameter Learning Using The Em Algorithm, Aniruddha Basak, Irina Brinster, Ole J. Mengshoel

Ole J Mengshoel

Stochastic Optimal Control In Nonlinear Systems, Celestin Nkundineza

Celestin Nkundineza

Stochastic control is an important area of research in engineering systems that undergo disturbances. Controlling individual states in such systems is critical. The present investigation is concerned with the application of the stochastic optimal control strategy developed by To (2010) and its implementation as well as providing computed results of linear and nonlinear systems under stationary and nonstationary random excitations. In the strategy the feedback matrix is designed based on the achievement of the objectives for individual states in the system through the application of the Lyapunov equation for the system. Each diagonal element in the gain or associated gain …

Exploring Engineering, B.S. Hoyt, D.J. Cartwright, R.G. Mcginnis, Maurice Aburdene

Maurice Aburdene

Engineering faculty members at Bucknell University have established a course required for freshman engineering students and open to liberal arts students. The course has been designed to stimulate and enhance student interest in all the engineering disciplines at Bucknell. The course ranges broadly across small groups, faculty-lead recitations, laboratory experiences, student design projects, traditional lectures, and guest speakers. The exploring engineering course has completed its second year. The authors describe the course, the changes made since the initial offering and the impact on the students and faculty involved. They also present and interpret student evaluations of the course.(4 refs)

An Integrated Environment For Filter Design, J.K Andersen, Maurice Aburdene

Maurice Aburdene

Analog filters and direct digital filters are implemented using digital signal processing techniques. Specifically, Butterworth, Elliptic, and Chebyshev filters are implemented using the Motorola 56001 Digital Signal Processor by the integration of three software packages: MATLAB, C++, and Motorola's Application Development System. The integrated environment allows the novice user to design a filter automatically by specifying the filter order and critical frequencies, while permitting more experienced designers to take advantage of MATLAB's advanced design capabilities. This project bridges the gap between the theoretical results produced by MATLAB and the practicalities of implementing digital filters using the Motorola 56001 Digital Signal …

Wow! Linear Systems And Signal Processing Is Fun!, Maurice Aburdene, Kundan Nepal

Maurice Aburdene

We describe a recent offering of a linear systems and signal processing course for third-year electrical and computer engineering students. This course is a pre-requisite for our first digital signal processing course. Students have traditionally viewed linear systems courses as mathematical and extremely difficult. Without compromising the rigor of the required concepts, we strived to make the course fun, with application-based hands-on laboratory projects. These projects can be modified easily to meet specific instructors' preferences. © 2011 IEEE.(17 refs)

Parallel Vector Processing Of Multidimensional Orthogonal Transforms For Digital Signal Processing Applications, M. El-Sharkawy, W. Tsang, Maurice Aburdene

Maurice Aburdene

The performance of the parallel vector implementation of the one- and two-dimensional orthogonal transforms is evaluated. The orthogonal transforms are computed using actual or modified fast Fourier transform (FFT) kernels. The factors considered in comparing the speed-up of these vectorized digital signal processing algorithms are discussed and it is shown that the traditional way of comparing th execution speed of digital signal processing algorithms by the ratios of the number of multiplications and additions is no longer effective for vector implementation; the structure of the algorithm must also be considered as a factor when comparing the execution speed of vectorized …

At The Tone, The Time Will Be... Unknown – A Perspective On The Evolution Of Time In Telecommunications, Robert Iannucci

Robert A Iannucci

No abstract provided.

Role Of Induction Motors In Voltage Instability And Coordinated Reactive Power Planning, Venkat Krishnan

Venkat Kumar Krishnan

No abstract provided.