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2006

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Articles 3331 - 3360 of 3391

Full-Text Articles in Engineering

State Of The Art For Differential Circuits In Wireless Transceivers: A New Wideband Active Balun In Sige Bicmos Technology, Balwant Godara, Alain Fabre Jan 2006

State Of The Art For Differential Circuits In Wireless Transceivers: A New Wideband Active Balun In Sige Bicmos Technology, Balwant Godara, Alain Fabre

Turkish Journal of Electrical Engineering and Computer Sciences

The aim of this paper is 3-fold: firstly, to provide a comprehensive overview of the use of differential circuits for analogue signal processing in wireless transceivers; secondly, to describe, in detail, single-ended signal to differential conversion, and the corresponding theory of such devices, their characterisation, various methods of implementation, and comparative analyses of their performance; lastly, to propose a new transistor-based solution for wideband baluns. This novel solution is based on the current conveyor and has been modelled using the transistor parameters of a 0.35 \mu m SiGe BiCMOS technology. The salient features of the new implementation are: (a) stable …

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A Pi Controller Based On Gain-Scheduling For Synchronous Generator, Alireza Sedaghati Jan 2006

A Pi Controller Based On Gain-Scheduling For Synchronous Generator, Alireza Sedaghati

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper a gain- scheduling scheme of a proportional integral (GSPI) controller is proposed for a synchronous generator. In presented scheme, both proportional and integral gains are allowed to vary within a predetermined range. In order to validate the effectiveness of GSPI controller, simulation studies for a single-machine infinite bus power system are used .The results verify improved performance of GSPI controller comparing to conventional AVR under various operating conditions.

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Agents For Integrating Distributed Data For Complex Computations, Ahmed M. Khedr, Raj Bhatnagar Jan 2006

Agents For Integrating Distributed Data For Complex Computations, Ahmed M. Khedr, Raj Bhatnagar

Turkish Journal of Electrical Engineering and Computer Sciences

Algorithms for many complex computations assume that all the relevant data are available on a single node of a computer network. In the emerging distributed and networked knowledge environments, databases relevant for computations may reside on a number of nodes connected by a communication network. These data resources cannot be moved to other network sites due to privacy, security, and size considerations. The desired global computation must be decomposed into local computations to match the distribution of data across the network. The capability to decompose computations must be general enough to handle different distributions of data and different participating nodes …

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Statistical Model Of Hot-Carrier Degradation And Lifetime Prediction For P-Mos Transistors, Firat Kaçar, Ayten Kuntman, Hakan Kuntman Jan 2006

Statistical Model Of Hot-Carrier Degradation And Lifetime Prediction For P-Mos Transistors, Firat Kaçar, Ayten Kuntman, Hakan Kuntman

Turkish Journal of Electrical Engineering and Computer Sciences

Along with advances in microelectronics, and computer and space technologies, device dimensions are becoming smaller; as a result, hot-carrier effect, lifetime prediction, and reliability become more important concepts for MOS transistors. In this paper, the degradation in the drain current and threshold voltage of P-MOS transistors are observed by operating the devices under voltage stress conditions. Using the observation results, the effect of hot-carriers was investigated statistically and a new statistical method for modeling was proposed as an alternative to those given in the literature. The linear regression method is used to estimate the power, Weibull, and logarithmic parameters, and …

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The Effect Of Collector Doping On Inp-Based Double Heterojunction Bipolar Transistors, Serkan Topaloğlu, Jörn Driesen, Werner Prost, Franz Josef Tegude Jan 2006

The Effect Of Collector Doping On Inp-Based Double Heterojunction Bipolar Transistors, Serkan Topaloğlu, Jörn Driesen, Werner Prost, Franz Josef Tegude

Turkish Journal of Electrical Engineering and Computer Sciences

High current effects on double heterojunction bipolar transistor (DHBT) performance were investigated. Three DHBTs with different collector doping densities were grown and processed. DC and RF measurements were performed to evaluate the influence of collector doping and the related Kirk effect on HBT performance. In addition to these samples, the Kirk effect was proven on SHBTs and the delay of this effect on submicron HBTs was investigated.

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Digital Fractional Frequency Synthesizer Based On Counters, Milan Stork Jan 2006

Digital Fractional Frequency Synthesizer Based On Counters, Milan Stork

Turkish Journal of Electrical Engineering and Computer Sciences

This paper describes the architecture of a new pure digital frequency synthesizer based on pulse generators, counters and a register. The technique described here is much simpler than other methods. The synthesizer presented is suitable for the design of VLSI architectures or for programmable large-scale integration circuits.

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State-Space Synthesis Of Current-Mode First-Order Log-Domain Filters, Ali̇ Kirçay, Uğur Çam Jan 2006

State-Space Synthesis Of Current-Mode First-Order Log-Domain Filters, Ali̇ Kirçay, Uğur Çam

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes current-mode first-order log-domain filters, which are systematically derived using the state-space synthesis procedure. First-order low-pass, high-pass, and all-pass responses are obtained with different circuit types. The filter circuits have very simple structures, since they use only bipolar junction transistors (BJTs) and a grounded capacitor. They can be electronically tuned by changing an external current. The filters have a greater bandwidth due to inherently current-mode and log-domain operation. PSPICE simulations are given to confirm the theoretical analysis.

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Space-Time Block Coding For Multiple Transmit Antennas Over Time-Selective Fading Channels, Ioannis Erotokritou Jan 2006

Space-Time Block Coding For Multiple Transmit Antennas Over Time-Selective Fading Channels, Ioannis Erotokritou

LSU Master's Theses

The last decade we have witnessed an extraordinary growing interest in the field of wireless communications. Wireless industry has recently turned into a technology known as Multiple-Input Multiple-Output (MIMO) to minimize errors and optimize data speed. This is done by using multiple transmit and receive antennas, as well as appropriate space-time block code techniques. Due the fact that time-selective fading channels exist, the assumption that the channel is being static over the length of the codeword does not apply in this thesis. The channel state varies over the number of signal intervals, and in such case the orthogonality of the …

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Effect Of Repetitions On Static And Dynamic Strength, Sai Chaitanya Reddy Bogolu Jan 2006

Effect Of Repetitions On Static And Dynamic Strength, Sai Chaitanya Reddy Bogolu

LSU Master's Theses

The objective of this study was to investigate the effect of repetitions on static and dynamic strength. The study is divided into two parts, the first part investigated static and dynamic strength during one, three and six repetitions per minute, and the second part of the study analyzed dynamic strength data collected using the Multiaxial Multipurpose Isokinetic Dynamometer. The study comprised of dynamic strength test data at three speeds of one, five and ten inch per second. Five male subjects participated in the first part of the study, and the results were analyzed by plotting a time series to observe …

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Rfid Technology Use In Assembly And Disassembly Processes, Gordana Ostojić, Milovan Lazarević, Vukica Jovanović, Stevan Stankovski, Ilija Ćosić Jan 2006

Rfid Technology Use In Assembly And Disassembly Processes, Gordana Ostojić, Milovan Lazarević, Vukica Jovanović, Stevan Stankovski, Ilija Ćosić

Engineering Technology Faculty Publications

Modern production conditions demand the application of the concept of distributed production. Today companies are specialized for partial technology processes. Hundreds, sometimes even thousands, of collaborative processes depend on workers’ interaction and communication in product assembly and disassembly phases. RFID technologies can be really helpful in identifying objects in terms of sustainable development, regarding disassembly, recycling and reuse. In this paper we presented VCDE system architecture and the realization method of RFID technology as well as the data acquisition using RFID technology during the product lifecycle from the design process, production, assembly, usage, and an special example is given regard- …

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Analysis Of Bioengineered Concrete For Use In A Submerged Reef Type Breakwater, Tyler Ray Ortego Jan 2006

Analysis Of Bioengineered Concrete For Use In A Submerged Reef Type Breakwater, Tyler Ray Ortego

LSU Master's Theses

The oysterbreak is a method of growing an oyster reef into a wave attenuating device. A study was conducted to determine an optimal material for the oysterbreak. As oysters grow on the oysterbreak, wave energy in the lee of the structure is reduced. It was predicted that more rapid oyster growth would lead to a more rapid reduction of wave energy. Louisiana is losing coastal marshes at an alarming rate. Wave action from storms erodes sediments from Louisiana's shorelines and barrier islands. Structures such as the oysterbreak may be used to protect Louisiana’s fragile shorelines. A material for the oysterbreak …

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Integrated Circuit Metrology By Multilevel Patterning Technology, Li Jiang Jan 2006

Integrated Circuit Metrology By Multilevel Patterning Technology, Li Jiang

LSU Doctoral Dissertations

A low cost, high accuracy method is described in detail for measuring image placement in integrated circuit manufacture. The method measures both the overlay between levels and the absolute placement of features in a single level. The overlay is measured by a technique which views multiple levels separately. The absolute distances between features on a test wafer are measured by comparing the features to precision gratings. Optical imaging techniques are described for viewing and analyzing the grating images, as well as for measuring distortions in the observing microscope and a video camera. These techniques permit image placement measurements to be …

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Active Control Of Spray Combustion, Onur Tuncer Jan 2006

Active Control Of Spray Combustion, Onur Tuncer

LSU Doctoral Dissertations

Effect of a forced dilution air jet on air-fuel spray mixing and emissions has been investigated. Temperature measurements have been made at a number of forcing frequencies in the range of 100-1100 Hz and blowing ratios between 6-15. Open-loop flame response to forcing has also been acquired by recording pressure and heat release spectra. The results show that the mean temperature field inside the flame can be altered due to jet modulation. Significant effects are observed by forcing at locations close to the dump plane. Enhancements in temperature of the order of 100–200 ˚C, and reduction in pattern factor of …

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Mimo-Ofdm Communication Systems: Channel Estimation And Wireless Location, Zhongshan Wu Jan 2006

Mimo-Ofdm Communication Systems: Channel Estimation And Wireless Location, Zhongshan Wu

LSU Doctoral Dissertations

In this new information age, high data rate and strong reliability features our wireless communication systems and is becoming the dominant factor for a successful deployment of commercial networks. MIMO-OFDM (multiple input multiple output-orthogonal frequency division multiplexing), a new wireless broadband technology, has gained great popularity for its capability of high rate transmission and its robustness against multi-path fading and other channel impairments. A major challenge to MIMO-OFDM systems is how to obtain the channel state information accurately and promptly for coherent detection of information symbols and channel synchronization. In the first part, this dissertation formulates the channel estimation problem …

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Design And Test Of A Displacement Workspace Mapping Station For Articular Joints, Michael Daly Guillet Jan 2006

Design And Test Of A Displacement Workspace Mapping Station For Articular Joints, Michael Daly Guillet

LSU Master's Theses

In 2003, 267,000 Americans received total knee replacements prohibiting high impact athletics for the remainder of a patient’s life. A better understanding of the movement and constraint of the knee is necessary to provide more realistic motion of or possibly eliminate the need for joint prosthetics. Fixed Orientation Displacement Workspaces (FODW) can be applied to study the relationship of the passive constraint system and six (6) degree of freedom (DOF) movement of the human knee. A FODW consists of the volume of possible positions the tibia/fibula can occupy relative to a fixed femur without changing the relative orientation of the …

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Influence Of Typha Latifolia And Phragmites Communis Root Matter On Degredation Of Aged 1,2,3,4-Tetrachlorobenzene In Bayou Sediments, Elaiza Maria Alvarez Jan 2006

Influence Of Typha Latifolia And Phragmites Communis Root Matter On Degredation Of Aged 1,2,3,4-Tetrachlorobenzene In Bayou Sediments, Elaiza Maria Alvarez

LSU Master's Theses

The purpose of this study was to investigate the effects of Typha latifolia and Phragmites communis root matter in degradation of sediments contaminated with aged 1,2,3,4- Tetrachlorobenzene (1,2,3,4-TeCB). In the present study, complete reductive dechlorination of 1,2,3,4-TeCB was observed in root matter systems, contrasting sediment with no roots present. Microcosms amended with Phragmites communis roots achieved the greatest first-order reaction rate constant over a 4-week period (0.113 d-1, half-life time of 6.13 days). Typha latifolia roots also played an important role in reductive dehalogenation of 1,2,3,4-TeCB, although the first-order reaction rate constant observed within the same period of …

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Compiler Optimization Techniques For Scheduling And Reducing Overhead, Tong-Chai Wang Jan 2006

Compiler Optimization Techniques For Scheduling And Reducing Overhead, Tong-Chai Wang

LSU Doctoral Dissertations

Exploiting parallelism in loops in programs is an important factor in realizing the potential performance of processors today. This dissertation develops and evaluates several compiler optimizations aimed at improving the performance of loops on processors. An important feature of a class of scientific computing problems is the regularity exhibited by their access patterns. Chapter 2 presents an approach of optimizing the address generation of these problems that results in the following: (i) elimination of redundant arithmetic computation by recognizing and exploiting the presence of common sub-expressions across different iterations in stencil codes; and (ii) conversion of as many array references …

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Performance Modeling Of Explosively Actuated Devices, Adam M. Braud Jan 2006

Performance Modeling Of Explosively Actuated Devices, Adam M. Braud

LSU Master's Theses

Explosively actuated devices (pin pullers, cable cutters, valves, etc) are used extensively to perform critical functions for aerospace, industrial, and defense related applications. The failure of these devices have led to a greater effort to quantify device design and performance. This thesis describes the actuation process of an explosively actuated valve, including: 1) the burning of the solid explosive HMX (C4H8N8O8) and production of its high pressure gas products, 2) the mass transfer of gas products through an actuator to an expansion volume including choked flow effects, 3) the resulting piston motion …

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Rice Processing: Milling And Value-Added Effects, Rebecca C. Schramm Jan 2006

Rice Processing: Milling And Value-Added Effects, Rebecca C. Schramm

LSU Master's Theses

The ultimate goal of this research is to characterize data from the laboratory, pilot, and industrial scale rice mills. Pilot and laboratory scale data are presented in this research. Two long grain rice cultivars were milled with two different scale mills. Cheniere and Cypress were milled with a McGill No. 2 mill and a pilot scale mill (Satake). Both material streams, rice kernels and bran, were collected and weighed. Measurements of Degree of milling, transparency, and whiteness were made with a milling meter (Satake). Yield and bran fraction were calculated. Samples of the bran were heat stabilized and prepared for …

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Towards A Generalized Team Task Complexity Model, Ashok Darisipudi Jan 2006

Towards A Generalized Team Task Complexity Model, Ashok Darisipudi

LSU Doctoral Dissertations

The objective of this research was to develop and validate a generalized team task-complexity model and framework by drawing on the literature from various team and task factors grouped into three task-dimensions, which compose task-complexity space and how these affect the task-performance. A number of task typologies have been presented in the teams' literature to better define and understand the critical role of the tasks and the associated team processes. In addition, most of the research work has defined team measures as highly abstract concepts not capable of providing the quantitative comparison of team performances from various domains. This research …

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A Generalized Approach For The Control Of Micro-Electromechanical Relays, Mohamed Abdelrahman Younis Jan 2006

A Generalized Approach For The Control Of Micro-Electromechanical Relays, Mohamed Abdelrahman Younis

LSU Master's Theses

MEMS (Micro-Electromechanical Systems) is an area of research and applications that is becoming increasingly popular. It's mainly concerned with integrating micro-mechanical transducers with micro-electronic circuits on common substrates, traditionally silicon, through micro-fabrication. Instead of traditionally having the transducer and the communicating (or control) circuit as two separate entities, MEMS miniaturizes and combines them on a single chip, giving it several advantages, saving space, money, and increasing the sensitivity and accuracy of the integrated system. A micro-electromechanical relay is a type of MEM devices that is becoming increasingly important in a wide range of industries such as the computer industry, the …

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A Nonlocal Model For Coupled Damage-Plasticity Incorporating Gradients Of Internal State Variables At Multiscales, Robert J. Dorgan Jan 2006

A Nonlocal Model For Coupled Damage-Plasticity Incorporating Gradients Of Internal State Variables At Multiscales, Robert J. Dorgan

LSU Doctoral Dissertations

The thermodynamically consistent formulation and the subsequent numerical implementation of a gradient enhanced continuum coupled damage-plasticity model as a constitutive framework to model ill-posed localization problems is presented. By the introduction of "nonlocal," gradient-enhanced measures in the plasticity potential function and yield criterion and in the damage potential function and damage criterion, the proposed model introduces microstructural characteristic material length scales which allows the size of localized zones to be predicted based on material constants, as opposed to local models where the loss of ellipticity causes the localized zones to be mesh dependent.
The gradient model proposed introduces non-linear functions …

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A Probabilistic Approach For Modeling And Real-Time Filtering Of Freeway Detector Data, Shourie Kondagari Jan 2006

A Probabilistic Approach For Modeling And Real-Time Filtering Of Freeway Detector Data, Shourie Kondagari

LSU Master's Theses

Traffic surveillance systems are a key component for providing information on traffic conditions and supporting traffic management functions. A large amount of data is currently collected from inductive loop detector systems in the form of three macroscopic traffic parameters (speed, volume and occupancy). Such information is vital to the successful implementation of transportation data warehouses and decision support systems. The quality of data is, however, affected by erroneous observations that result from malfunctioning or mis-calibration of detectors. The open literature shows that little effort has been made to establish procedures for screening traffic observations in real-time. This study presents a …

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Design Of Cmos Lc Voltage Controlled Oscillators, Chetan Shambhulinga Salimath Jan 2006

Design Of Cmos Lc Voltage Controlled Oscillators, Chetan Shambhulinga Salimath

LSU Master's Theses

This work presents the design and implementation of CMOS LC voltage controlled oscillators. On-chip planar spiral inductors and PMOS inversion mode varactors were utilized to implement the resonator. Two voltage controlled oscillators (VCOs) were realized as a part of this work, one designed to operate at 1.1 GHz while the second at 1.8 GHz. Both VCOs were implemented in a scalable digital CMOS process, with the former in a 1.5 micron CMOS process and the latter in a 0.5 micron technology. A simulation based methodology was adopted to arrive at a simple pi model used to model the metal and …

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Electrical And Computer Engineering Education In The 21^{St} Century: Issues, Perspectives And Challenges, Levent Sevgi̇ Jan 2006

Electrical And Computer Engineering Education In The 21^{St} Century: Issues, Perspectives And Challenges, Levent Sevgi̇

Turkish Journal of Electrical Engineering and Computer Sciences

No abstract provided.

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Engineering Education In The 21st Century: Issues And Perspectives, Leopold B. Felsen Jan 2006

Engineering Education In The 21st Century: Issues And Perspectives, Leopold B. Felsen

Turkish Journal of Electrical Engineering and Computer Sciences

No abstract provided.

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Electronic Publishing For Engineering Education, Donald G. Dudley Jan 2006

Electronic Publishing For Engineering Education, Donald G. Dudley

Turkish Journal of Electrical Engineering and Computer Sciences

Electronic transmission of text is a revolution in progress with a profound effect on engineering education. As with all revolutions, the result is both a threat and a promise. The promise is the ease and speed of dissemination of text. The threat involves serious difficulties that arise in efforts to protect the intellectual property rights of the authors and publishers of the technical information. In this paper, we discuss both the threat and the promise. We highlight the differences in dealing with books and with journals. We give a wide range of examples from both inside of and outside of …

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Speaking With Numbers: Scientific Literacy And Public Understanding Of Science, Levent Sevgi̇ Jan 2006

Speaking With Numbers: Scientific Literacy And Public Understanding Of Science, Levent Sevgi̇

Turkish Journal of Electrical Engineering and Computer Sciences

Public understanding of science and scientific literacy is discussed. Scientific method, scientific process and scientific filter are reviewed accordingly. Basic terms of measurement and numerical calculation are outlined. Finally, fundamental requirements of scientific literacy and critical response skills are presented.

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Introducing Students To Communications Concepts Using Optical And Low-Power Wireless Devices, James M. Conrad, Ivan Howitt Jan 2006

Introducing Students To Communications Concepts Using Optical And Low-Power Wireless Devices, James M. Conrad, Ivan Howitt

Turkish Journal of Electrical Engineering and Computer Sciences

Wireless communication has become an important feature for commercial products and a popular research topic within the last ten years. There are now more mobile phone subscriptions than wired-line subscriptions. Lately, one area of commercial interest has been low-cost, low-power, and short-distance wireless communication used for "personal wireless networks." Technology advancements are providing smaller and more cost effective devices for integrating computational processing, wireless communication, and a host of other functionalities. These embedded communications devices will be integrated into applications ranging from homeland security to industry automation and monitoring. They will also enable custom tailored engineering solutions, creating a revolutionary …

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Infusing Technical Communication And Teamwork Within The Ece Curriculum, By April Kedrowicz, Sundy Watanabe, Damon Hall, Cynthia Furse Jan 2006

Infusing Technical Communication And Teamwork Within The Ece Curriculum, By April Kedrowicz, Sundy Watanabe, Damon Hall, Cynthia Furse

Turkish Journal of Electrical Engineering and Computer Sciences

This paper highlights a unique approach to infusing formal training and practice in oral and written communication and teamwork development in the Department of Electrical and Computer Engineering (ECE) at the University of Utah. Faculty and graduate (Ph.D.) students from the College of Humanities have teamed up with faculty from engineering to develop communication and teamwork instruction that is integrated into the existing engineering curriculum. These skills are used as a vehicle to provide better understanding of engineering concepts and their applications.

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