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Full-Text Articles in Electrical and Computer Engineering

Showcase For The Advantages Of Asynchronous Vs. Synchronous Circuits, Justin Roark May 2011

Showcase For The Advantages Of Asynchronous Vs. Synchronous Circuits, Justin Roark

Electrical Engineering Undergraduate Honors Theses

Synchronous circuits dominate the semiconductor industry, but asynchronous circuitry is becoming more popular and will continue to do so, as evidenced by the International Technology Roadmap for Semiconductors. Asynchronous circuits, when compared to synchronous circuits, display tolerance to supply voltage and temperature variation. The goal of this project is to demonstrate these two advantages. The project will compare two microcontrollers, a synchronous 8051 and an asynchronous 8031, which will both play a song under various stresses. Note that an 8031 and 8051 are the same, except for the 8051 includes an on-chip instruction memory, whereas the 8031's is off-chip. When …


Reducing Energy Usage Of Null Convention Logic Circuits Using Null Cycle Reduction Combined With Supply Voltage Scaling, Brett Sparkman May 2011

Reducing Energy Usage Of Null Convention Logic Circuits Using Null Cycle Reduction Combined With Supply Voltage Scaling, Brett Sparkman

Electrical Engineering Undergraduate Honors Theses

The NULL Cycle Reduction (NCR) technique can be used to improve the performance of the NULL Convention Logic (NCL) circuit at the expense of power and area. However, by decreasing the supply voltage of certain components, the power of the NCR circuit can be reduced. Since NCR has increased performance, it could be possible to decrease the power while maintaining the original performance of the circuit. To verify this, the NCR circuit will be implemented using a 4-bit by 4-bit dual-rail multiplier as the test circuit. This circuit will be simulated in ModelSim to ensure functionality, synthesized into a Verilog …


A Methodology For Implementing Rf Bists In Production Testing To Replace Rf Conventional Tests, Deepa Mannath Dec 2010

A Methodology For Implementing Rf Bists In Production Testing To Replace Rf Conventional Tests, Deepa Mannath

Graduate Theses and Dissertations

Production testing of Radio Frequency (RF) devices is challenging due to the complex nature of the tests that have to be performed to verify functionality. In this dissertation a methodology to replace the complex and expensive RF functional tests with defect-oriented Built-in Self Tests (BiSTs) is detailed. If a design has sufficient margin to RF specifications then RF tests can be replaced with structural tests using a new data analysis technique called quadrant analysis, which is presented. Data from the analysis of over one million production units of said System on Chip (SoC) is presented along with the results of …


Multi-Threshold Cmos Circuit Design Methodology From 2d To 3d, Ross Josiah Thian Dec 2010

Multi-Threshold Cmos Circuit Design Methodology From 2d To 3d, Ross Josiah Thian

Graduate Theses and Dissertations

A new and exciting approach in digital IC design in order to accommodate the Moore's law is 3D chip stacking. Chip stacking offers more transistors per chip, reduced wire lengths, and increased memory access bandwidths. This thesis demonstrates that traditional 2D design flow can be adapted for 3D chip stacking. 3D chip stacking has a serious drawback: heat generation. Die-on-die architecture reduces exposed surface area for heat dissipation. In order to reduce heat generation, a low power technique named Multi-Threshold CMOS (MTCMOS) was incorporated in this work. MTCMOS required designing a power management unit (to control when and which gates …


A Study On The Effect Of Random Placement And Orientation On The Resonance Of Multiple Split Ring Resonators, Michael Buscher Sep 2009

A Study On The Effect Of Random Placement And Orientation On The Resonance Of Multiple Split Ring Resonators, Michael Buscher

Electrical Engineering Undergraduate Honors Theses

This thesis project experimentally studies the effect of placing split-ring oscillators (SRR) in a non-periodic arrangment with random orientation. This is contrary to typical structures which are simulated as a single unit cell with a periodic boundry condition to emulate an infinite array of SSR's. Samples are measured using a near-field free-space measurement system with full Thru, Reflect, Line (TRL) calibration and the application of time domain gating. Results, in the form of scattering (S) parameters, are compared with previous measurments of periodic SRR structures in order to study the influence, if any, of periodicity in the frequency response of …


Computational Modeling Of The Internal Structure In The Breast, Jordan Greenlee May 2009

Computational Modeling Of The Internal Structure In The Breast, Jordan Greenlee

Electrical Engineering Undergraduate Honors Theses

Many researchers who are using microwave modality in the area of breast cancer detection employ oversimplified models of the internal structure of the breast. Use of engineered or biologically inaccurate models could render inaccurate results. Therefore, a mathematical biological model is implemented in this work and aims to bridge the gap between biologists and engineers. The results of the proposed breast duct model show that older women have smaller breast ducts leading to less dense breasts, which is in agreement with medical knowledge. Also, younger women have larger breast ducts leading to more dense breasts which are consistent with the …


Low Voltage, Low Power, Bulk-Driven Amplifier, Shama Huda May 2009

Low Voltage, Low Power, Bulk-Driven Amplifier, Shama Huda

Electrical Engineering Undergraduate Honors Theses

The importance of low voltage and low powered electronics is increasing with advances in medical electronics. This branch of electronics specifically requires low voltage and low power to make efficient innovative medical equipment. Low power electronics are also desirable because it conserves energy and power. This paper proposes a design of a differential in - differential our amplifier that uses a bulk-driven differential pair for the input pair. In addition, it also used bulk-driven current mirrors for the tail current sink and the active loads. The bulkdriven technique helps to achieve the low voltage design. 90nm CMOS technology was considered …


Preliminary Study Based On The Ddscat Software To Explore Increasing The Contrast Of Breast Tumors For Microwave Imaging, Rachel Megee May 2009

Preliminary Study Based On The Ddscat Software To Explore Increasing The Contrast Of Breast Tumors For Microwave Imaging, Rachel Megee

Electrical Engineering Undergraduate Honors Theses

Microwave technology is being researched for its capabilities to detect breast tumors less painfully and at earlier stages. It is necessary to have a large contrast between cancerous and healthy tissue when the microwaves are reflected off the breast tissue. To model the increasing contrast between cancerous breast tissue and healthy breast tissue, the DDSCAT code is investigated for its capabilities and analyzed for its accuracy in scattering calculations. The DDSCAT is used to model homogenous and inhomogeneous targets. Simulations of the scattering field by the homogeneous and inhomogeneous targets are conducted and compared to Mie theory calculations for accuracy. …


Developing Equivalent Second Order System Models And Robust Controls For Servo-Drive Related Systems, Christopher Hoyt May 2009

Developing Equivalent Second Order System Models And Robust Controls For Servo-Drive Related Systems, Christopher Hoyt

Electrical Engineering Undergraduate Honors Theses

Numerous industrial and other plant processes today represent systems in which a motor supplies torque to a drive disk, which in turn through a pulley system drives a larger load. Developing models for these complex systems can become time consuming and expensive. A simple second order system approximation can be developed for these systems under certain system conditions which can greatly reduce the complexity of controlling and modeling the system. A second order feed-forward notch controller can then be introduced to the system which greatly improves performance. The results of this proposed method of approximating complex servo-drive systems show that …


A Study Of Switched-Capacitor Filters, Kacie Thomas Dec 2008

A Study Of Switched-Capacitor Filters, Kacie Thomas

Electrical Engineering Undergraduate Honors Theses

This paper presents the basic principles of the switched-capacitor circuit. In order to become more acquainted with the workings and design of filters and switched-capacitor filters specifically, an example filter was designed based on a set of parameters. It was constructed starting in the passive stage, then the active stage and finally the switched-capacitor filter was generated. All of these circuits were also simulated using SwitcherCAD and Saber. Then, a switched-capacitor filter designed by Auburn University was redesigned using the same process as the example circuit. It was also simulated in all three stages. The results from this design are …


Microwave Dielectroscopy Of Breast Tissue Phantoms In The 5.8-40 Ghz Range, Binh Tran Aug 2008

Microwave Dielectroscopy Of Breast Tissue Phantoms In The 5.8-40 Ghz Range, Binh Tran

Electrical Engineering Undergraduate Honors Theses

Based on the high contrast in dielectric properties between the low-water-contain sample and the high-water-content one, we can determine whether the tissue sample is cancerous or normal. In order to make the measurement repeatable and convenient, some phantom materials, which have the same dielectric properties of human tissues, have been prepared. These phantom tissues are made from gelatin, water with honey syrup and Sodium Chloride (NaCl). In this project, we are going to measure and compare the dielectric properties of different types of phantom tissues by using focused beam antennas. The purpose of this project is to perform a systematic …


Measurement Of Absolute Argon Excited State Populations And Electron Energy Distribution Functions In An Ar-A-Si Plasma, Katherine Herring May 2008

Measurement Of Absolute Argon Excited State Populations And Electron Energy Distribution Functions In An Ar-A-Si Plasma, Katherine Herring

Electrical Engineering Undergraduate Honors Theses

Deposition systems utilizing plasma are used for a variety of tasks, including tool coatings and creating thin-film materials. In order to have repeatable results, the internal conditions of a plasma chamber need to be known. This project centered on the use of data from optical emissions and a Langmuir probe from an argon plasma amorphous silicon depositing system. An electron energy distribution function (EEDF) was obtained from manipulation of the Langmuir probe data. This EEDF was then input to an argon collisional-radiative model (CRM) to obtain the electron population of the 4p level of the argon plasma. Through an absolute …


Dna Comparison Chip: Circuit Design And Evaluation, Tushar Bajaj May 2008

Dna Comparison Chip: Circuit Design And Evaluation, Tushar Bajaj

Electrical Engineering Undergraduate Honors Theses

The purpose of this project was to: First, design a microchip that is capable of comparing strings of DNA sequences. Second, evaluate the functioning of such a microchip and how it can implemented in various real world applications. Physically, this microchip will act as an attachment to any computer. The computer will send two strings of DNA sequences-one library string and one pattern string-and the chip will output the number of matches that exist between the two strings (at a given position of the pattern string with respect to the library string). The circuit design is based on a 600 …


A Timer Module For An 8051 Microcontroller, Troy England May 2008

A Timer Module For An 8051 Microcontroller, Troy England

Electrical Engineering Undergraduate Honors Theses

A timer module for an 8051 Microcontroller is designed from the ground up. It could potentially be integrated into a larger 8051 for use in lunar and Martian missions. It follows through a synchronous digital design flow from HDL code through layout verification. The timer shows functionality at 100MHz with some minor glitches.


A Review Of Variable Valve Timing Devices, Paul Shelton May 2008

A Review Of Variable Valve Timing Devices, Paul Shelton

Mechanical Engineering Undergraduate Honors Theses

Variable valve timing (VVT) has evolved from simple, manual controlled engine management to automatic, electronic works of engineering. Starting from the need for more power and extending into fuel efficiency and low emissions, VVT has evolved from the constant changing of needs. This paper summarizes various devices used to control the timing of valves from the early 1920s up until 2007.


Improvement Of Prony's Method Of System Identification Vianonlinear Parameter Transformation, C. Wu Jan 2008

Improvement Of Prony's Method Of System Identification Vianonlinear Parameter Transformation, C. Wu

Journal of the Arkansas Academy of Science

This paper presents an approach to improve Prony’s method of identifying a linear time-invariant system. The method is based on a nonlinear transformation of parameters, which leads to data averaging. The method yields better results than a direct application of the least squares approach to Prony’s method. A numerical example is given to demonstrate the improvement attained by the new algorithm. Signals are assumed to be contaminated by zero-mean Gaussian white noise.


Improvement To The Data Logging Capability Of A Cough Monitoring System, Matthew Barlow Jan 2007

Improvement To The Data Logging Capability Of A Cough Monitoring System, Matthew Barlow

Inquiry: The University of Arkansas Undergraduate Research Journal

Data logging capability of a previously developed self contained cough recorder using an accelerometer as the sensing element is improved by using a secure digital memory card for later retrieval on a computer. Firmware is developed to enhance the functionality of the cough recorder. Existing libraries are modified for increased write rates. Increased writing speed allows 8-bit sampling at rates exceeding 8kHz, allowing for detailed time and frequency domain analysis. Additional features have also been developed to enable easy management of recordings, such as a file system compatibility with Microsoft Windows., and unique file names for each recording.


Parameter Extraction Software For Silicon Carbide Schottky, Merged Pin Schottky And Pin Power Diode Models, Edgar Cilio Jan 2004

Parameter Extraction Software For Silicon Carbide Schottky, Merged Pin Schottky And Pin Power Diode Models, Edgar Cilio

Inquiry: The University of Arkansas Undergraduate Research Journal

A software program for on-state parameter extraction is presented for the realization of a high quality model for SiC Schottky, Merged PiN Schottky, and PiN Power diodes based on McNutt and Mantooth's Comprehensive SiC Diode model [ 1 ].


Investigation On How To Improve Latent Semantic Analysis Performance, Thao Doan Jan 2003

Investigation On How To Improve Latent Semantic Analysis Performance, Thao Doan

Inquiry: The University of Arkansas Undergraduate Research Journal

Latent Semantic Analysis (LSA) is a matching technique capable of recognizing the semantic relationships of data that ordinary techniques such as string matching cannot. This is especially valuable for data integration applications, like those of Acxiom, where data items are usually related by context, rather than in a literal match. Even though it has been shown that LSA is 30% more effective in finding and ranking relevant pieces of information than existing string-by-string matching techniques (Deerwester et al., 1990; Dumais, 1995), the performance of the LSA seems to be affected by the presence of shared words, or “noise”, in data. …


Novel High Frequency Silicon Carbide Static Induction Transistor-Based Test-Bed For The Acquisition Of Sic Power Device Reverse Recovery Characteristics, Kevin M. Speer, Ty R. Mcnutt, Alexander B. Lostetter, H. Alan Mantooth, Kraig J. Olejniczak Jan 2003

Novel High Frequency Silicon Carbide Static Induction Transistor-Based Test-Bed For The Acquisition Of Sic Power Device Reverse Recovery Characteristics, Kevin M. Speer, Ty R. Mcnutt, Alexander B. Lostetter, H. Alan Mantooth, Kraig J. Olejniczak

Journal of the Arkansas Academy of Science

A test system is presented that utilizes a high-frequency Silicon Carbide (SiC) Static Induction Transistor (SIT) in place of the traditional MOSFET to test reverse recovery characteristics for the new class of SiC power diodes. An easily implementable drive circuit is presented that can drive the high-frequency SIT. The SiC SIT is also compared to a commonly used Si MOSFET in the test circuit application.


Parameter Extraction Software For Compact Diode Model, Maruf Hossain, Edgar Cilio, Ty R. Mcnutt, Alexander B. Lostetter, H. Alan Mantooth Jan 2003

Parameter Extraction Software For Compact Diode Model, Maruf Hossain, Edgar Cilio, Ty R. Mcnutt, Alexander B. Lostetter, H. Alan Mantooth

Journal of the Arkansas Academy of Science

No abstract provided.


Testing And Modeling Electrical Characteristics Of Novel Silicon Carbide (Sic) Static Induction Transistors (Sits), Avinash S. Kashyap, Sharmila D. Mangan Lal, Ty R. Mcnutt, Alexander B. Lostetter, H. Alan Mantooth Jan 2003

Testing And Modeling Electrical Characteristics Of Novel Silicon Carbide (Sic) Static Induction Transistors (Sits), Avinash S. Kashyap, Sharmila D. Mangan Lal, Ty R. Mcnutt, Alexander B. Lostetter, H. Alan Mantooth

Journal of the Arkansas Academy of Science

No abstract provided.


The Need For Pfc Abatement In Semiconductor Manufacturing, Mohsen Manesh, Brian Kendrick Jan 2002

The Need For Pfc Abatement In Semiconductor Manufacturing, Mohsen Manesh, Brian Kendrick

Inquiry: The University of Arkansas Undergraduate Research Journal

Perfluorocompounds (PFCs) are highly stable chemical compounds used in two integral steps of semiconductor manufacturing: chemical vapor deposition (CVD) chambers and etch chambers. Unfortunately, PFCs are also greenhouse gases linked to global warming. This, combined with their long atmospheric lifetimes gives them global warming potentials much higher than C02 the principal greenhouse gas. In a series of voluntary agreements with the United States and other national governments, the worldwide semiconductor industry has set a goal of reducing PFC emissions to 90% of their 1995 levels. To reach this goal, researchers have explored four main methods of reduction: substitution of PFCs, …


Modeling Of Electrofusion Coils For Performance Optimization, Steve Farmer, Robert A. Sims Jan 2002

Modeling Of Electrofusion Coils For Performance Optimization, Steve Farmer, Robert A. Sims

Journal of the Arkansas Academy of Science

Modeling physical parameters provides a virtual design environment allowing the confirmation and optimization of electrofusion characteristics. Finite element incorporate physical parameters and their interactions along common boundaries defined within a model geometry. The electrofusion of polymeric piping is a widely accepted means of assembling piping systems with zero-leakage integrity. The key parameters in the fusion process are the coil resistance, the current passing through the coil and the time the current is applied. Modeling the coil and applying current to the model is accomplished using the MATLABpartial differential equations (PDE) toolbox. This paper presents the method of modeling and the …


Co-Polymers Of Furan With Pyrrole Or Thiophene: A Synthetic Study, Rose M. Mcconnell, Walter E. Godwin, Susan E. Baker, Kenya Powell, Martha Baskett, Amy Morara, Xiadong Ma Jan 2002

Co-Polymers Of Furan With Pyrrole Or Thiophene: A Synthetic Study, Rose M. Mcconnell, Walter E. Godwin, Susan E. Baker, Kenya Powell, Martha Baskett, Amy Morara, Xiadong Ma

Journal of the Arkansas Academy of Science

The use of conductive polymers as a substitute for metallic conductors and semiconductors has attracted much attention in the literature. In particular, aromatic heterocyclic polymers constitute an important class since they possess chemical and electrical stability in both the oxidized (doped) and neutral (undoped) state. Doping a polymer allows one to vary its electrical, mechanical, optical, and thermal properties. The properties of these polymers are promising for their many technological uses such as antistatic coatings, solar cells, and electronic devises. Polyfuran is among the least common heterocyclic polymers. Polyfuran has been reported to be much less stable that either polypyrrole …


A Method Of Implementing The Interleaver In 3g Wireless Communication Systems For Randomization Of Burst Errors, Eric Duquette Jan 2001

A Method Of Implementing The Interleaver In 3g Wireless Communication Systems For Randomization Of Burst Errors, Eric Duquette

Inquiry: The University of Arkansas Undergraduate Research Journal

In less than a year or two, third generation ( 3G) wireless communication systems will be replacing the currently existing second generation (2G) wireless systems and be used worldwide. The 3G systems will have a higher data transfer capacity, which allows for simultaneous data, voice, and video transfer (e.g., multimedia applications) while most of 2G systems only allow for low-rate data and voice transfer. The wireless communications industry has set standards for 3G, which detail various operations of the technology. It should be noted that the 3G standards outline only the different operations and not the processes for the production …


Improved Methods For Electroplating Cadmium Sulfide Thin Films, Brandon Kemp, Robert Engelken, Arif Raza, Wasim Aleem, Imran Khan, Chris Barber Jan 1996

Improved Methods For Electroplating Cadmium Sulfide Thin Films, Brandon Kemp, Robert Engelken, Arif Raza, Wasim Aleem, Imran Khan, Chris Barber

Journal of the Arkansas Academy of Science

We report improved methods for electroplating cadmium sulfide (CMS) films. Aprevious problem was cracking/flaking of films deposited from organic solutions of elemental sulfur; attempts to improve adhesion via bath additives reduced grain size. Aqueous baths of thiosulfate ions yield cadmium-richness at low T temperatures (T), long deposition times, and/or poor bath stability. Developments in our work to be discussed include (1) plating ofuniform, adherent, and stoichiometric CdS from tetraethylene baths of CdCl 2 and elemental sulfur at T >70° C with minimal cracking/flaking, (2) improved uniformity/ adherence by use of CdL>, and (3) swept voltage methods in aqueous thiosulfate …


Characterization Of Cadmium Sulfide Films Deposited By Chemical Bath Method, Quazi Galib Samdami, Hameed A. Naseem, W. D. Brown Jan 1995

Characterization Of Cadmium Sulfide Films Deposited By Chemical Bath Method, Quazi Galib Samdami, Hameed A. Naseem, W. D. Brown

Journal of the Arkansas Academy of Science

Thin filmcadmium sulfide is a leading candidate in the fabrication of large area solar cells. The chemical bath deposition method is one of the least expensive sources for the fabrication of device quality cadmium sulfide thin films.Inthe present work, the deposition of CdS films on glass substrate from an aqueous solution containing cadmium acetate, ammonia, ammonium acetate, and thiourea are investigated. The structural properties of CdS films are characterized. Good quality thin films within 0.1 - o.5 |im thickness were obtained in30 minute deposition time, and at 70*-90*C. The films show preferential orientations. The optical transmittance of the films are …


Polishing Of Cvd-Diamond Substrates Using Reactive Ion Etching, Gopi M.R. Sirineni, Hameed A. Naseem, W. D. Brown, A. P. Malshe Jan 1995

Polishing Of Cvd-Diamond Substrates Using Reactive Ion Etching, Gopi M.R. Sirineni, Hameed A. Naseem, W. D. Brown, A. P. Malshe

Journal of the Arkansas Academy of Science

Multichip modules (MCM)have proved to be a viable packaging technology for achieving small size and high performance. By their nature, MCMs typically integrate multiple bare die into a module that can be the plastic or ceramic package. As a result, the MCMrequires an efficient mechanism for removing excess heat. Diamond with its excellent thermal conductivity, is the ideal choice as a substrate material for these applications. Chemical vapor deposited (CVD) diamond substrates makes possible the practical realization of a novel diamond based 3-D MCM. However, the diamond films grown by CVD technique are polycrystalline and have non-uniform filmroughness and randomly …


Diagnostics Of Cdte Electrodeposition By Rest Potential Voltammetry, Brandon Kemp, Robert Engelken, Arif Raza, Arees Siddiqui, Omer Mustafa Jan 1995

Diagnostics Of Cdte Electrodeposition By Rest Potential Voltammetry, Brandon Kemp, Robert Engelken, Arif Raza, Arees Siddiqui, Omer Mustafa

Journal of the Arkansas Academy of Science

Due to the extreme sensitivity of the partial elemental currents (i.e.,iCd, iTe) and, hence, stoichiometry to deposition voltage, temperature, mass transport, and ambient light intensity during electrodeposition of semiconductor films, it is important to implement in-situ methods for monitoring the stoichiometry and related semiconductor efficacy of the growing film. We report investigation of open circuit rest potential (Eoc) voltammetry as one such method during electrodeposition of CdTe from aprotic electrolytes such as ethylene glycol. Plots of transient open circuit potential versus sweep voltage exhibit distinct transition and plateau structures corresponding to Te, CdTe, and Cd phases and correlating with the …