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Articles 24481 - 24510 of 27369

Full-Text Articles in Engineering

Rostir, Inc.: The Fabrication Of Ultra High Value Chip Resistors & Business Plan Development, Jonathan E. Ross Jan 2006

Rostir, Inc.: The Fabrication Of Ultra High Value Chip Resistors & Business Plan Development, Jonathan E. Ross

Journal of the Microelectronic Engineering Conference

The concept of this project was comprised of a proof of concept design with an additional focus on entrepreneurship. To define clearly, this project included the selection of a device to fabricate, where a commercial market opportunity existed, using semiconductor technologies while simultaneously developing a business plan marketed towards further funding. This project required complete design of the Ultra High Value Chip Resistor as well as a process design for fabrication of the resistors. Gigaohm resistance values were achieved and varied with a range between 60- ]6OGohms, with an average of 99.5 Gigaohms, the expected value was 86.6 Gigaohms. Some …


Microfabrication And Commercialization Of A Polymer-Absorption Chemical Gas Sensor, Stephen P. Parshall Jan 2006

Microfabrication And Commercialization Of A Polymer-Absorption Chemical Gas Sensor, Stephen P. Parshall

Journal of the Microelectronic Engineering Conference

A polymer-absorption chemical gas sensor has been microfabricated and tested to discriminate varying concentrations of ethanol vapors. The polymer, PEDOT (3,4- polyethylenedioxythiopene-polystyrenesulfonate) was combined with carbon to function as the sensing device. The sensor demonstrated well-defined responses to the smallest tested ethanol concentrations of 0.1 μl (185 ppm) and is expected to be accurate to much smaller ppm levels. When packed with the proposed external feedback network, the device may be suitable for field-breath alcohol level detection as an alternative to expensive fuel-cell and chromatography based devices. The proposed device will be portable, user friendly and inexpensive to operate.


Investigation Into The Use Of Su8 In High Aspect Ratio Applications, Kody Okafor Jan 2006

Investigation Into The Use Of Su8 In High Aspect Ratio Applications, Kody Okafor

Journal of the Microelectronic Engineering Conference

The objective for this project was to investigate the feasibility of making high aspect ratio SU8 structures via contact lithography with a target of 10:1 and line width resolution of about 2μm. Factors investigated include exposure dose of 150mJ/cm2, 200mJ/cm2, 250mJ/cm2 and PEB times of 1.5mm, 3mm and 4.5mm. The responses were line width CD and sidewall angle. The approach was first to optimize the thickness of the resist coated. This was done by generating a spin speed curve for the SU8 formulation used. Secondly, was to optimize the line width CD. A 32 full factorial experiment was performed. From …


Microfabrication Of Biocompatible Stimulation Electrode Arrays For Cochlear Implants, Ward A. Johnson Jan 2006

Microfabrication Of Biocompatible Stimulation Electrode Arrays For Cochlear Implants, Ward A. Johnson

Journal of the Microelectronic Engineering Conference

A proof of concept to microfabricate an electrode array suitable for use with cochlear implants was successfully manufactured and tested. Thirty microns of photoimageable polyimide was used as a flexible substrate. The array was inserted 20mm into an artificial cochlea filled with a saline and soap solution that simulates intracochlear fluid and hyaluronic acid (used as a lubricant), which is comparable to the performance of current manufactured products.


Ultrafiltration Membrane Process For Pyrogen Removal In The Preparation Of Water For Injection (Wfi), Thet N. Soe Jan 2006

Ultrafiltration Membrane Process For Pyrogen Removal In The Preparation Of Water For Injection (Wfi), Thet N. Soe

Inquiry: The University of Arkansas Undergraduate Research Journal

An artificial kidney process based on ultrafiltration (called hemodiafiltration) more effectively removes blood toxins, particularly those of higher molecular weight, than conventional dialysis. In hemodiafiltration, replacement liquid must be added directly to the patient's blood to replace liquid filtered out of the blood in the ultrafiltration cartridge. This replacement liquid is made up of' "water for injection" (WFI) and other components such as salts and glucose. WFI is produced either by distillation or reverse osmosis and has a cost of $1.00 per liter. A patient with kidney problems would require three hemodiafiltration treatments per week, each requiring 70-80 liters of …


Evaluation Of Rice Hulls As A Lignocellulosic Substitute In Wood Plastic Composites, P. Jack Bourne Jan 2006

Evaluation Of Rice Hulls As A Lignocellulosic Substitute In Wood Plastic Composites, P. Jack Bourne

Inquiry: The University of Arkansas Undergraduate Research Journal

Rising raw material costs and shortage of woody materials necessitate alternative sources for lignocellulosic material in wood plastic composites (WPC). This study was conducted to evaluate rice hull (RH), an agricultural residue, as a cellulosic substitute in WPC. Samples were fabricated with approximately 4% zinc stearate, 48% high-density polyethylene obtained from recycled plastics and 48% lignocellulosic material by mass. The composition of the lignocellulosic material was changed from 0 to 100% RH at 20% increments while the remainder was wood flour. The extruded sampled were tested for mechanical properties such as specific gravity, water absorption, linear coefficients of thermal expansion, …


A Study Of The Impact Of Prognostic Errors On System Performance, Mauricio Carrasco Jan 2006

A Study Of The Impact Of Prognostic Errors On System Performance, Mauricio Carrasco

Inquiry: The University of Arkansas Undergraduate Research Journal

Condition-based maintenance is growing in popularity as a means of improving equipment maintenance efficiency. Whether it be the maintenance of an airplane, a computer system, or any type of physical system, the prognostic tools associated with condition-based maintenance are subject to statistical error. These errors can lead to unnecessary preventive maintenance due to underestimation of system remaining life and unnecessary system failures due to overestimation of system remaining life. What is not clear is if these statistical errors outweigh the benefits of a condition-based maintenance policy. This study attempts to address this concern through the evaluation and comparison of three …


Virtual Prototype Of Shuttle Bay Door, Nick Harrington, Raphael Schulz, Pierre Chapron Jan 2006

Virtual Prototype Of Shuttle Bay Door, Nick Harrington, Raphael Schulz, Pierre Chapron

The Journal of Undergraduate Research

This study analyzed the motion of the Space Shuttle free floating in space after one of its bay doors is opened and closed. Kane's method and Autolev motion simulation software were used to carry out simulation and analysis. The Space Shuttle has two large bay doors that open simultaneously, but for our study we analyzed a hypothetical situation, in which only one door functioned properly, in order to achieve amplified results. To model this system we used a rigid body to resemble the Shuttle and an attached rotating flap to resemble the door. Since the Shuttle is free floating in …


Dynamical Multi-Body Gyroscopic Motion Simulation, Andy Ries, Johnathan Deppe Jan 2006

Dynamical Multi-Body Gyroscopic Motion Simulation, Andy Ries, Johnathan Deppe

The Journal of Undergraduate Research

In this paper, the motion of a three-degree-of-freedom gyro scope is analyzed in three different force scenarios. The equations of motion for the gyroscope are derived by hand as well as derived by the dynamical analysis software, Autolev These equations are compared with each other to show the consistency between the two methods and the time savings of using software applications for analyzing complex multi-body dynamical systems. The Autolev™ program drastically reduced the workload for determining the motion equations and the program even compiled Matlab code that was used to produce numerical values to show the respective motion of each …


Cutting Force And Temperature Prediction For Turning Processes, Brian Carstensen, Aaron Eich, Tyler Schroeder, Ryan Joens Jan 2006

Cutting Force And Temperature Prediction For Turning Processes, Brian Carstensen, Aaron Eich, Tyler Schroeder, Ryan Joens

The Journal of Undergraduate Research

The machining process modeling software allows researchers to run simulations of real world situations without the costs and risks of operating the machining tool and mining a work piece or cutting tool.We ran several simulations with combinations of high speed steel, carbide, and cubic-boron-nitride for our tool materials, and 1045 steel, 15-5PH, or Inconel 718 for workpiece material options. The numerical simulations or experiments assumed physical, mechanical, and thermal properties representative of work-piece materials and tool material. Cutting forces were determined in the numerical simulations.


An Experience On Problem Based Learning In An Engineering Faculty, Cüneyt Güzeli̇ş Jan 2006

An Experience On Problem Based Learning In An Engineering Faculty, Cüneyt Güzeli̇ş

Turkish Journal of Electrical Engineering and Computer Sciences

In 2001, Engineering Faculty of Dokuz Eylül University has started to change its undergraduate education in a radical way. As being among the first examples in the world, the Departments of Electrical and Electronics, Geological and Geophysics Engineering in 2002 and Mining Engineering Department in 2003 have adopted the so-called "modular-staged problem based active learning system". The system is based on real engineering problems which values teamwork and the integration of information from different disciplines and it places the student at the center of the learning process. The faculty has learned many things and it needs to learn many other …


An International Dialogue On Electrical Engineering Education, Thales Papazoglou Jan 2006

An International Dialogue On Electrical Engineering Education, Thales Papazoglou

Turkish Journal of Electrical Engineering and Computer Sciences

. PAPAZOGLOU Chairman -- ELCOMPEET'04 Technological Educational Institute of Crete, GREECE e-mail: [email protected]


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.


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 …


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.


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 …


Computational Sciences: At The Intersection Of Science And Engineering--Case Study For Academic And Research Programs, Menas Kafatos, Peter Becker, Zafer Boybeyi̇ Jan 2006

Computational Sciences: At The Intersection Of Science And Engineering--Case Study For Academic And Research Programs, Menas Kafatos, Peter Becker, Zafer Boybeyi̇

Turkish Journal of Electrical Engineering and Computer Sciences

No abstract provided.


Readjusting The Current Trend In Electrical Power Engineering, Johan Smit, Peter Morshuis, Edward Gulski Jan 2006

Readjusting The Current Trend In Electrical Power Engineering, Johan Smit, Peter Morshuis, Edward Gulski

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper the electrical power education curriculum is analyzed from the viewpoint of the electrical power industry and from the viewpoint of young people that contemplate their future academic study. From the perspective of young people in industrialized countries contemplating their future and the possibilities of an academic study, the current curriculum in (power) engineering lacks attraction. The number of freshmen still shows a decreasing trend. This paper is aimed to be a contribution towards readjusting this trend


Online Learning Resource For Smooth Transition From High School To Engineering Education, Riadh W. Y. Habash, Christine Suurtaam, Mustapha C. E. Yagoub, Karima Kara, Ghanim Ibrahim Jan 2006

Online Learning Resource For Smooth Transition From High School To Engineering Education, Riadh W. Y. Habash, Christine Suurtaam, Mustapha C. E. Yagoub, Karima Kara, Ghanim Ibrahim

Turkish Journal of Electrical Engineering and Computer Sciences

Although high school mathematics curriculum documents in Ontario, Canada have, for the past two decades, made calls for classroom practices involving both modeling and applications, students still experience difficulties in moving into a university engineering program. This paper discusses a new initiative in online learning and the teaching of mathematical modeling and applications in engineering education at the University of Ottawa, Canada. In particular, we explore how modeling and Internet technologies can enhance progress in engineering education.


Modeling And Simulation Concepts In Engineering Education: Virtual Tools, Levent Sevgi̇ Jan 2006

Modeling And Simulation Concepts In Engineering Education: Virtual Tools, Levent Sevgi̇

Turkish Journal of Electrical Engineering and Computer Sciences

This article reviews fundamental concepts of modeling and simulation in computational sciences, such as a model, analytical- and numerical-based modeling, simulation, validation, verification, etc., in relation to the virtual labs widely-offered as parts of engineering education. Virtual tools that can be used in electromagnetic engineering are also introduced.


A Labview-Based Virtual Instrument For Engineering Education: A Numerical Fourier Transform Tool, Levent Sevgi̇, Çağatay Uluişik Jan 2006

A Labview-Based Virtual Instrument For Engineering Education: A Numerical Fourier Transform Tool, Levent Sevgi̇, Çağatay Uluişik

Turkish Journal of Electrical Engineering and Computer Sciences

Engineering is based on practice. The minima of this practice should be given during the university education. This has become more and more comprehensive and expensive parallel to high-technology devices developed and presented to societies. Computers, microprocessor-based devices, programmable systems on Chip (PSoC), etc., make engineering education not only very complex but interdisciplinary as well. Building undergraduate labs has become more and more expensive if only physical experimentation and hands-on training are targeted. On the other hand, simple, comparatively much cheaper software may turn a regular personal computer (PC) into a virtual lab. The key question therefore is, to establish …


Two, Three And Four-Dimensional Electromagnetics Using Differential Forms, Karl F. Warnick, Peter Russer Jan 2006

Two, Three And Four-Dimensional Electromagnetics Using Differential Forms, Karl F. Warnick, Peter Russer

Turkish Journal of Electrical Engineering and Computer Sciences

The exterior calculus of differential forms provides a mathematical framework for electromagnetic field theory that combines much of the generality of tensor analysis with the computational simplicity and concreteness of the vector calculus. We review the pedagogical aspects of the calculus of differential forms in providing distinct representations of field intensity and flux density, physically meaningful graphical representations for sources, fields, and fluxes, and a picture of the curl operation that is as simple and intuitive as that of the gradient and divergence. To further highlight the benefits of differential forms notation, we demonstrate the flexibility of the calculus of …


Complex Analysis Of The Lossy-Transmission Line Theory: A Generalized Smith Chart, E. Gago-Ribas, C. Dehesa-Martinez, M. J. Gonzalez-Morales Jan 2006

Complex Analysis Of The Lossy-Transmission Line Theory: A Generalized Smith Chart, E. Gago-Ribas, C. Dehesa-Martinez, M. J. Gonzalez-Morales

Turkish Journal of Electrical Engineering and Computer Sciences

It has been very usual in the specialized literature to skip the detailed study of the lossy transmission line theory by reducing it to the low-loss approximation. Although this is valid in the most common practical cases, the study of the general lossy case becomes very important due to the fact that it makes possible a better and deeper understanding of the physical effects associated to general losses, as well as the low-loss frequency-dependent regime. Besides, the analysis of the general case provides important results that may be extended to the analysis of real waveguiding systems, facilitating the understanding and …


Speech Pre-Processing For Pitch And Pitch-Cylce Evolutions Smoothing, Hassan Farsi Jan 2006

Speech Pre-Processing For Pitch And Pitch-Cylce Evolutions Smoothing, Hassan Farsi

Turkish Journal of Electrical Engineering and Computer Sciences

In low bit rate speech coders, pitch is usually transmitted once per frame and, when needed, the intermediate pitch values are obtained by interpolation between 2 adjacent pitch values. Although pitch usually evolves slowly, sometimes it has irregular variations and the estimated pitch differs from the real one. In addition, some speech coders, e.g., waveform interpolation coders, rely on smooth pitch-cycle evolutions to extract speech model parameters in the analysis stage. However, non-stationary characteristics of speech may lead to inaccurate estimation of the parameters. This affects the synthesised speech quality. We propose a pre-processor, which modifies the residual speech signal …


Human Identification Using Gait, Murat Eki̇nci̇ Jan 2006

Human Identification Using Gait, Murat Eki̇nci̇

Turkish Journal of Electrical Engineering and Computer Sciences

Gait refers to the style of walking of an individual. This paper presents a view-invariant approach for human identification at a distance, using gait recognition. Recognition of a person from their gait is a biometric of increasing interest. Based on principal component analysis (PCA), this paper describes a simple, but efficient approach to gait recognition. Binarized silhouettes of a motion object are represented by 1-D signals, which are the basic image features called distance vectors. The distance vectors are differences between the bounding box and silhouette, and are extracted using 4 projections of the silhouette. Based on normalized correlation of …


Adaptive 3d Visual Servo Control Of Robot Manipulators Via Composite Camera Inputs, Türker Şahi̇n, Erkan Zergeroğlu Jan 2006

Adaptive 3d Visual Servo Control Of Robot Manipulators Via Composite Camera Inputs, Türker Şahi̇n, Erkan Zergeroğlu

Turkish Journal of Electrical Engineering and Computer Sciences

This paper considers the problem of position control of robot manipulators via visual servoing in the presence of uncertainty associated with the robot dynamics and the vision system. Specifically, an adaptive controller is designed to compensate for the uncertainties associated with the mechanical parameters of the robot manipulator and the intrinsic parameters of the cameras. The 3D visual information is obtained from the composite inputs of two separate cameras placed in the robot work space. Despite the uncertainties associated with the camera system and robot dynamics the proposed adaptive controller achieves asymptotic end effector position tracking. A Lyapunov based approach …


Uplink Practical Capacity And Interference Statistics Of Wcdma Cigar-Shaped Microcells For Highways In Rural Zones With Non-Uniform Spatial Traffic Distribution And Imperfect Power Control, Bazil Taha Ahmed, Miguel Calvo Ramon, Leandro De Haro-Ariet Jan 2006

Uplink Practical Capacity And Interference Statistics Of Wcdma Cigar-Shaped Microcells For Highways In Rural Zones With Non-Uniform Spatial Traffic Distribution And Imperfect Power Control, Bazil Taha Ahmed, Miguel Calvo Ramon, Leandro De Haro-Ariet

Turkish Journal of Electrical Engineering and Computer Sciences

The capacity (the maximum number of users per sector that the system can support) and the interference statistics (expected value and variance) of sectors composed of cigar-shaped WCDMA microcells are studied. A model of 5 microcells is used to analyze the uplink capacity and interference statistics. The microcells are assumed to exist in rural zone highways. The capacity and the interference statistics of the microcells are studied for different non-uniform spatial traffic distributions. As user density decreases away from the base station, the capacity of the sector increases due to the reduced total power transmitted by the interfering users.


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 …


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 …


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.