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Electrical and Computer Engineering

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Selected Works

2011

Articles 1 - 30 of 168

Full-Text Articles in Engineering

Pso Based Optimal Placement And Setting Of Facts Devicesfor Improving The Performance Of Power Distribution System, Tibin Joseph Dec 2011

Pso Based Optimal Placement And Setting Of Facts Devicesfor Improving The Performance Of Power Distribution System, Tibin Joseph

Tibin Joseph

No abstract provided.


Improve Design For Automated Tajweed Checking Rules Engine Of Quranic Verse Recitation: A Review, Noor Jamaliah Ibrahim, Zulkifli Mohd Yusoff, Zaidi Razak Dec 2011

Improve Design For Automated Tajweed Checking Rules Engine Of Quranic Verse Recitation: A Review, Noor Jamaliah Ibrahim, Zulkifli Mohd Yusoff, Zaidi Razak

Noor Jamaliah Ibrahim

Generally, reliable speech recognition is a hard problem that required a combination solution of many techniques. Thus, the combinations of Al-Quran with speech recognition system is quite challenging task to be implemented. It is because the Quran sound, which had been recited by most of reciters will probably tend to differ a lot from one person to another. Although those Quranic sentences were particularly taken from the same verse, but the way of the sentence in Al-Quran been recited or delivered may be different, depend on reciters with the different levels of understanding of Tajweed rules. This paper seeks to …


Analytical Analysis Of Second-Order Stokes Wave In Brillouin Ring Fiber Laser, Faisal Rafiq Mahamd Adikan Dec 2011

Analytical Analysis Of Second-Order Stokes Wave In Brillouin Ring Fiber Laser, Faisal Rafiq Mahamd Adikan

Faisal Rafiq Mahamd Adikan

This paper details a theoretical modeling of Brillouin ring fiber laser which incorporates the interaction between multiple Brillouin Stokes signals. The ring cavity was pumped at several Brillouin pump (BP) powers and the output was measured through an optical coupler with various coupling ratios. The first-order Brillouin Stokes signal was saturated with the presence of the second-order Stokes signal in the cavity as a result of energy transfer between them. The outcome of the study found that the optimum point for the first-order Stokes wave performance is at laser power reduction of 10%. Resultantly, at the optimum output coupling ratio …


Wideband Voltage Variable Attenuator With Fewer Components, Chin-Leong Lim Nov 2011

Wideband Voltage Variable Attenuator With Fewer Components, Chin-Leong Lim

Chin-Leong Lim

RF/microwave amplifying devices have unit-to-unit gain variability. So, in some critical applications such as the low noise amplifier (LNA) in cellular basestations, the gain has to be adjusted in production using a voltage-variable attenuators (VVA). Constant impedance VVAs such as the PI and the bridged-TEE topologies require between 14 to 18 components, including 2 to 4 active devices, but their large dynamic (attenuation) range is wasted in this amplifier gain adjustment application. To create a more economical and smaller VVA for amplifier gain adjustment, we investigated a new circuit configuration comprising one active and four passive components. This paper describes …


Causes Of The Blackout: The Grid Operation And Environment, Almoataz Youssef Abdelaziz Nov 2011

Causes Of The Blackout: The Grid Operation And Environment, Almoataz Youssef Abdelaziz

Almoataz Youssef Abdelaziz

Despite huge advancements in different power system components, operations, and protection technologies, todayÕs power systems are more vulnerable to blackouts than ever before. Deregulation, market competition, and increasing demands, in addition to less investment in transmission assets, all contribute to the critical state power systems operate at. Two main characteristics of the power system are always being put under the scope of study, reliability and security. This paper takes a subjective thorough look at the previous numerous blackout events, surveyed by the authors, that have been encountered by different power systems around the globe and classifies them into different types …


Interconnection Of Oman And Uae Electric Power Systems, Omar H. Abdalla, Rashid Al-Badwawi, Hilal S. Al-Hadi, Hisham A. Al-Riyami, Ahmed Al-Nadabi, Karim Karoui, Ariadne Szekut Nov 2011

Interconnection Of Oman And Uae Electric Power Systems, Omar H. Abdalla, Rashid Al-Badwawi, Hilal S. Al-Hadi, Hisham A. Al-Riyami, Ahmed Al-Nadabi, Karim Karoui, Ariadne Szekut

Omar H. Abdalla

The objective of this paper is to assess the impact of interconnecting Oman and United Arab Emirates (UAE) through the existing 220kV, 46.7km double circuit transmission line rated 762MVA for each circuit. A model is developed to represent both systems of Oman and UAE based on the EUROSTAG© software. Load flow and contingency studies are presented to evaluate the compliance of the interconnected system for security criteria N and N-1. Calculations are applied to two operating conditions (peak and minimum load) and for three energy exchange cases: no exchange and maximum exchanges in both directions. Short circuit studies are presented …


Turbine, Vijaya Krushna Varma Mr Nov 2011

Turbine, Vijaya Krushna Varma Mr

VIJAYA KRUSHNA VARMA Mr

Varma designed ultra modern and high efficiency turbines which can use gas, steam or fuels as feed to produce electricity or mechanical work for wide range of usages and applications in industries or at work sites. Varma turbine engines can be used in all types of vehicles. These turbines can also be used in aircraft, ships, battle tanks, dredgers, mining equipment, earth moving machines etc, Salient features of Varma Turbines. 1. Varma turbines are simple in design, easy to manufacture, easy to operate and maintain. 2. Varma turbines are less expensive. 3. Varma turbines have a great power to weight …


Anatomy Of A Nanoscale Conduction Channel Reveals The Mechanism Of A High-Performance Memristor, Feng Miao, John Strachan, Jianhua Yang, M Zhang, Ilan Goldfarb, Antonio Torrezan, Peter Eschbach, Ronald Kelley, Gilberto Medeiros-Ribeiro, R Stanley Williams Nov 2011

Anatomy Of A Nanoscale Conduction Channel Reveals The Mechanism Of A High-Performance Memristor, Feng Miao, John Strachan, Jianhua Yang, M Zhang, Ilan Goldfarb, Antonio Torrezan, Peter Eschbach, Ronald Kelley, Gilberto Medeiros-Ribeiro, R Stanley Williams

Jianhua Yang

By employing a precise method for locating and directlyimaging the active switching region in a resistive random access memory (RRAM) device, a nanoscale conducting channel consisting of an amorphous Ta(O) solid solution surrounded by nearly stoichiometric Ta2O5 is observed. Structural and chemical analysis of the channel combined with temperature-dependent transport measurements indicate a unique resistance switching mechanism.


Dual-Phase Sensing For Early Detection Of Prepreg Structural Failures Via Etched Cladding Bragg Grating, Faisal Rafiq Mahamd Adikan Nov 2011

Dual-Phase Sensing For Early Detection Of Prepreg Structural Failures Via Etched Cladding Bragg Grating, Faisal Rafiq Mahamd Adikan

Faisal Rafiq Mahamd Adikan

A dual-phase optical fiber-based sensor for early detection against prepreg structural failures is proposed and successfully demonstrated. The sensor consists of an etched fiber Bragg grating (FBG) mounted onto an aluminium plate. The sensor is tested using a simple pressure and petrochemical test rig. By observing the shift of the reflected wavelength of the FBG sensor we can simultaneously detect two parameters: (i) pressure and (ii) petrochemical. The experimental results show the potential of using the FBG sensor for early detection of submarine oil pipe leaking. (C) 2011 Elsevier B.V. All rights reserved.


Response Characterization Of Electroactive Polymers As Mechanical Sensors, G. Alici, Geoffrey M. Spinks, J. D. Madden, Y. Wu, G G. Wallace Oct 2011

Response Characterization Of Electroactive Polymers As Mechanical Sensors, G. Alici, Geoffrey M. Spinks, J. D. Madden, Y. Wu, G G. Wallace

Gordon Wallace

The characterization of the dynamic response (including transfer function identification) of trilayer polypyrrole (PPy) type conducting polymer sensors is presented. The sensor was built like a cantilever beam with the free end stimulated through a mechanical lever system, which provided displacement inputs. The voltage generated and current passing between the two outer PPy layers as a result of the input was measured to model the output/input behavior of the sensors based on their experimental current/displacement and voltage/displacement frequency responses. We specifically targeted the low-frequency behavior of the sensor as it is a relatively slowsystem. Experimental transfer function models were generated …


Wide Aea Protection (Wap) Systems: Benefits, Schemes, And Examples, Almoataz Youssef Abdelaziz Oct 2011

Wide Aea Protection (Wap) Systems: Benefits, Schemes, And Examples, Almoataz Youssef Abdelaziz

Almoataz Youssef Abdelaziz

No abstract provided.


A Tutorial On Bayesian Networks For System Health Management, Arthur Choi, Lu Zheng, Adnan Darwiche, Ole J. Mengshoel Oct 2011

A Tutorial On Bayesian Networks For System Health Management, Arthur Choi, Lu Zheng, Adnan Darwiche, Ole J. Mengshoel

Ole J Mengshoel

Bayesian networks have established themselves as an indispensable tool in artificial intelligence, and are being used effectively by researchers and practitioners more broadly in science and engineering. The domain of system health management, including diagnosis, is no exception. In fact, diagnostic applications have driven much of the developments in Bayesian networks over the past few decades. In this chapter, we provide a gentle and accessible introduction to modeling and reasoning with Bayesian networks, with the domain of system health management in mind.


Risk-Based Critical Infrastructure Priorities For Emp And Solar Storms, George H. Baker Iii Oct 2011

Risk-Based Critical Infrastructure Priorities For Emp And Solar Storms, George H. Baker Iii

George H Baker

Two electromagnetic phenomena have the potential to create continental-scale disasters. The first, nuclear electromagnetic pulse (EMP), results from a nuclear detonation high above the tropopause. The second, a major solar storm, or "solar tsunami" occurs naturally when an intense wave of charged particles from the sun perturbs the earth's magnetic field. Both phenomena can debilitate electrical and electronic systems necessary for the operation of infrastructure systems and services. One reason why a U.S. protection program has yet to be initiated is that policy makers continue to wrestle with the question of where to begin, given the Department of Homeland Security’s …


A Critical Review Of The Effectiveness Of Fiscal And Monetary Policies In The Pacific Island Countries (Pics) Between 1990-2010, Deogratias Harorimana Mr Oct 2011

A Critical Review Of The Effectiveness Of Fiscal And Monetary Policies In The Pacific Island Countries (Pics) Between 1990-2010, Deogratias Harorimana Mr

Dr Deogratias Harorimana

The purpose of this paper is to critically assess the effectiveness of Fiscal and Monetary Policies in the South Pacific Island Countries. The paper tracks down the economic growth for the last 20 years between 1990-2010, and drawing from key fiscal and monetary policies in place during the time under consideration, as well as specific interventions in the region, we find that: 1) While the South Pacific Island Countries (SPICs) particularly the six major economies (Solomon Islands, Fiji, Vanuatu, PNG, Samoa, Tonga) pursued fiscal and monetary policies for promoting growth and diversification of their economies, their fiscal policies relied heavily …


Issues In Human Capital Development : Lessons For Public Administration And Governance, Deogratias Harorimana Mr Oct 2011

Issues In Human Capital Development : Lessons For Public Administration And Governance, Deogratias Harorimana Mr

Dr Deogratias Harorimana

With few minerals or other natural resources, Rwanda believes that she can still achieve her ambitions by investing in human capital - her unique resource. If this ambition can be achieved, then is this the next role model for international development? We used a case study design and analysis methods to examine development models used elsewhere in recent decades, using both qualitative and quantitative data on Rwanda to establish the comparative advantages in relation to Singapore’s economic development model. The implications for international development are that (1) an effective human capital development strategy should be inclusive enough to respond to …


Aluminum Nitride Reconfigurable Rf-Mems Front-Ends, Augusto Tazzoli, Matteo Rinaldi, Chengjie Zuo, Nipun Sinha, Jan Van Der Spiegel, Gianluca Piazza Oct 2011

Aluminum Nitride Reconfigurable Rf-Mems Front-Ends, Augusto Tazzoli, Matteo Rinaldi, Chengjie Zuo, Nipun Sinha, Jan Van Der Spiegel, Gianluca Piazza

Chengjie Zuo

Aluminum Nitride based piezoelectric microelectromechanical systems (MEMS) technology has the potential to develop a fully integrated radio frequency (RF) platform that satisfies the requirements of next-generation communication standards: reconfigurability, miniaturization, and low power consumption. Here we report on the recent developments of this AlN thin-film based technology, namely resonators, filters, oscillators and switches. These examples highlight how MEMS will enable the mass manufacturing of reconfigurable RF front-ends.


Dual-Mode Resonator And Switchless Reconfigurable Oscillator Based On Piezoelectric Aln Mems Technology, Chengjie Zuo, Jan Van Der Spiegel, Gianluca Piazza Oct 2011

Dual-Mode Resonator And Switchless Reconfigurable Oscillator Based On Piezoelectric Aln Mems Technology, Chengjie Zuo, Jan Van Der Spiegel, Gianluca Piazza

Chengjie Zuo

For the first time, this work demonstrates a switchless dual-frequency (472 MHz and 1.94 GHz) reconfigurable CMOS oscillator using a single piezoelectric AlN microelectromechanical-systems resonator with coexisting S0 and S1 Lamb-wave modes of vibration. High performance (high quality factor Q and electromechanical coupling factor kt2 for a resonator and low phase noise for an oscillator) has been achieved for both the resonator and oscillator in terms of dual-mode operation. In particular, 1.94-GHz operation has the best phase noise performance at 1-MHz offset when compared with all previously reported CMOS oscillators that work at a similar frequency.


Distributed Generator And Their Effects On Distribution System Protection Performance, Hadi Zayandehroodi, Azah Mohamed, Hussain Shareef, Marjan Mohammadjafari Oct 2011

Distributed Generator And Their Effects On Distribution System Protection Performance, Hadi Zayandehroodi, Azah Mohamed, Hussain Shareef, Marjan Mohammadjafari

Dr. Hadi Zayandehroodi

The connection of distributed generators (DGs) to distribution networks greatly influences the performance and stability of such networks. Though DGs have significant economic and environmental benefits, increased penetration of DGs will impose significant technical barriers for the efficient and effective operation of bulk power systems. Increased fault current contribution and load flow changes are the major two impacts on utility systems, and these will affect existing protective relaying, especially overcurrent relays. To ensure safe and selective protection relay coordination, the impact of DGs should be taken into account when planning DG interconnection. This paper presents an introduction of distributed generators …


Analytical Study Of Nonlinear Phase Shift Through Stimulated Brillouin Scattering In Single Mode Fiber With The Pump Power Recycling Technique, Faisal Rafiq Mahamd Adikan Oct 2011

Analytical Study Of Nonlinear Phase Shift Through Stimulated Brillouin Scattering In Single Mode Fiber With The Pump Power Recycling Technique, Faisal Rafiq Mahamd Adikan

Faisal Rafiq Mahamd Adikan

We present a theoretical study of nonlinear phase shift through stimulated Brillouin scattering in single mode optical fiber. Analytical expressions describing the nonlinear phase shift for the pump and Stokes waves in the pump power recycling technique have been derived. The dependence of the nonlinear phase shift on the optical fiber length, the reflectivity of the optical mirror and the frequency detuning coefficient have been analyzed for different input pump power values. We found that with the recycling pump technique, the nonlinear phase shift due to stimulated Brillouin scattering reduced to less than 0.1 rad for 5 km optical fiber …


Construction Of The Next Generation Of Energy Efficient Light Boxes - Sponsored By Bayer Environmental Science, Gregory Keith Bartley Jr. Oct 2011

Construction Of The Next Generation Of Energy Efficient Light Boxes - Sponsored By Bayer Environmental Science, Gregory Keith Bartley Jr.

Gregory Keith Bartley Jr.

This short presentation includes an overview of features that went into constructing a new type of light box technology utilizing low-power usage LEDs and Low Density flexible Polymers. This light box was constructed for digital image analysis of plant health and ground cover using a Canon Powershot G12 camera and Sigma Scan Digital Image Analysis Software.


Semantic Geotagging: A Location-Based Hypermedia Approach To Creating Situational Awareness, Ray Bareiss, Martin Griss, Steven Rosenberg, Yu Zhang Sep 2011

Semantic Geotagging: A Location-Based Hypermedia Approach To Creating Situational Awareness, Ray Bareiss, Martin Griss, Steven Rosenberg, Yu Zhang

Ray Bareiss

As emergency first responders and commanders increasingly use mobile phones, tablets, and social media to communicate, coordinate, and manage information during disasters, we see a need and opportunity to provide a mobile device-appropriate semantic layer to a geographically-based common operating picture. The challenge is to provide a simple, usable structure for a rapidly growing body of information to simplify the development of situational awareness in an unfolding disaster. We use a hyperlinked structure based on the ASK model to organize information in a readily accessible form. In this paper we describe our initial design and experience with an Android-based prototype, …


Semantic Geotagging: A Location-Based Hypermedia Approach To Creating Situational Awareness, Ray Bareiss, Martin Griss, Steven Rosenberg, Yu Zhang Sep 2011

Semantic Geotagging: A Location-Based Hypermedia Approach To Creating Situational Awareness, Ray Bareiss, Martin Griss, Steven Rosenberg, Yu Zhang

Martin L Griss

As emergency first responders and commanders increasingly use mobile phones, tablets, and social media to communicate, coordinate, and manage information during disasters, we see a need and opportunity to provide a mobile device-appropriate semantic layer to a geographically-based common operating picture. The challenge is to provide a simple, usable structure for a rapidly growing body of information to simplify the development of situational awareness in an unfolding disaster. We use a hyperlinked structure based on the ASK model to organize information in a readily accessible form. In this paper we describe our initial design and experience with an Android-based prototype, …


Aluminum Nitride Reconfigurable Rf-Mems Front-Ends, Augusto Tazzoli, Matteo Rinaldi, Chengjie Zuo, Nipun Sinha, Jan Van Der Spiegel, Gianluca Piazza Sep 2011

Aluminum Nitride Reconfigurable Rf-Mems Front-Ends, Augusto Tazzoli, Matteo Rinaldi, Chengjie Zuo, Nipun Sinha, Jan Van Der Spiegel, Gianluca Piazza

Matteo Rinaldi

Aluminum Nitride based piezoelectric microelectromechanical systems (MEMS) technology has the potential to develop a fully integrated radio frequency (RF) platform that satisfies the requirements of next-generation communication standards: reconfigurability, miniaturization, and low power consumption. Here we report on the recent developments of this AlN thin-film based technology, namely resonators, filters, oscillators and switches. These examples highlight how MEMS will enable the mass manufacturing of reconfigurable RF front-ends.


Vva Extends Bw And Dynamic Range, Chin-Leong Lim Sep 2011

Vva Extends Bw And Dynamic Range, Chin-Leong Lim

Chin-Leong Lim

Voltage-variable attenuators (VVAs) enable gain adjustment in a wide range of applications, including in cable-television (CATV), satellite-television (SATV) systems, and even test equipment and measurement systems. The PI VVA configuration using PIN diodes is ubiquitous in CATV and SATV systems owing to its low part count, small size, constant impedance, high linearity, and multi-decade bandwidth. Presently, this class of VVAs have been under severe miniaturization pressure in order to shrink end-product size. To create the industry's smallest CATV/SATV-suitable VVA, we integrated all necessary components into a multi-chip-on-board (MCOB) package measuring 3.8 x 3.8 x 1.0 mm (14 mm square footprint). …


Bayesian Software Health Management For Aircraft Guidance, Navigation, And Control, Johann M. Schumann, Timmy Mbaya, Ole J. Mengshoel Sep 2011

Bayesian Software Health Management For Aircraft Guidance, Navigation, And Control, Johann M. Schumann, Timmy Mbaya, Ole J. Mengshoel

Ole J Mengshoel

Modern aircraft — both piloted fly-by-wire commercial aircraft as well as UAVs — more and more depend on highly complex safety critical software systems with many sensors and computer-controlled actuators. Despite careful design and V&V of the software, severe incidents have happened due to malfunctioning software.

In this paper, we discuss the use of Bayesian networks to monitor the health of the on-board software and sensor system, and to perform advanced on-board diagnostic reasoning. We focus on the development of reliable and robust health models for combined software and sensor systems, with application to guidance, navigation, and control (GN&C). Our …


Integrating Probabilistic Reasoning And Statistical Quality Control Techniques For Fault Diagnosis In Hybrid Domains, Brian Ricks, Craig Harrison, Ole J. Mengshoel Sep 2011

Integrating Probabilistic Reasoning And Statistical Quality Control Techniques For Fault Diagnosis In Hybrid Domains, Brian Ricks, Craig Harrison, Ole J. Mengshoel

Ole J Mengshoel

Bayesian networks, which may be compiled to arithmetic circuits in the interest of speed and predictability, provide a probabilistic method for system fault diagnosis. Currently, there is a limitation in arithmetic circuits in that they can only represent discrete random variables, while important fault types such as drift and offset faults are continuous and induce continuous sensor data. In this paper, we investigate how to handle continuous behavior by using discrete random variables with a small number of states, without using soft evidence, which is a traditional technique for handling continuous sensor data. We do so by integrating a method …


Construction Of A Mobile Spectrophotometer For Mapping Plant Health: Combining Crop Circle™ And Gps Technology, Gregory Keith Bartley Jr., Brandon J. Horvath Sep 2011

Construction Of A Mobile Spectrophotometer For Mapping Plant Health: Combining Crop Circle™ And Gps Technology, Gregory Keith Bartley Jr., Brandon J. Horvath

Gregory Keith Bartley Jr.

With the introduction of GPS technology, came the ability to produce maps of plant cover and health over large areas. By correlating the reflectance values of a plant with its respective GPS coordinates, we can form a bird’s eye view of relative plant health using different colors. The commercialization of high precision GPS receivers has allowed researchers to plot these maps with increased accuracy, limiting error to less than 1 inch.


Constructing New Technology: The Crop Circle Gps Cart In Pictures, Gregory Keith Bartley Jr., Brandon J. Horvath Sep 2011

Constructing New Technology: The Crop Circle Gps Cart In Pictures, Gregory Keith Bartley Jr., Brandon J. Horvath

Gregory Keith Bartley Jr.

The crop circle spectrometer represents a breakthrough in unbiased sensor data. Unlike traditional passive sensors, it pulses light at a speed of 20,000 times per second. With this comes the ability of these filters to discern reflectance measurements from that of natural sunlight, allowing it to be used in environments of sun, shade, and even darkness. From these various reflectance values at different wavelengths, we get measurements of plant health known as vegetation indices. And different vegetation indices can tell us different things about the health of a plant. Couple this with the recent advances in GPS technology, we can …


Pandaa: Physical Arrangement Detection Of Networked Devices Through Ambient-Sound Awareness, Zheng Sun, Aveek Purohit, Kaifei Chen, Shijia Pan, Trevor Pering, Pei Zhang Sep 2011

Pandaa: Physical Arrangement Detection Of Networked Devices Through Ambient-Sound Awareness, Zheng Sun, Aveek Purohit, Kaifei Chen, Shijia Pan, Trevor Pering, Pei Zhang

Zheng Sun

Future ubiquitous home environments can contain 10s or 100s of devices. Ubiquitous services running on these devices (i.e. localizing users, routing, security algorithms) will commonly require an accurate location of each device. In order to obtain these locations, existing techniques require either a manual survey, active sound sources, or estimation using wireless radios. These techniques, however, need additional hardware capabilities and are intrusive to the user. Non-intrusive, automatic localization of ubiquitous computing devices in the home has the potential to greatly facilitate device deployments.

This paper presents the PANDAA system, a zero-configuration spatial localization system for networked devices based on …


Pandaa: Physical Arrangement Detection Of Networked Devices Through Ambient-Sound Awareness, Zheng Sun, Aveek Purohit, Kaifei Chen, Shijia Pan, Trevor Pering, Pei Zhang Sep 2011

Pandaa: Physical Arrangement Detection Of Networked Devices Through Ambient-Sound Awareness, Zheng Sun, Aveek Purohit, Kaifei Chen, Shijia Pan, Trevor Pering, Pei Zhang

Aveek Purohit

Future ubiquitous home environments can contain 10s or 100s of devices. Ubiquitous services running on these devices (i.e. localizing users, routing, security algorithms) will commonly require an accurate location of each device. In order to obtain these locations, existing techniques require either a manual survey, active sound sources, or estimation using wireless radios. These techniques, however, need additional hardware capabilities and are intrusive to the user. Non-intrusive, automatic localization of ubiquitous computing devices in the home has the potential to greatly facilitate device deployments.

This paper presents the PANDAA system, a zero-configuration spatial localization system for networked devices based on …