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Optimized Class-E Rf Power Amplifier Design In Bulk Cmos, Tao Wang Aug 2007

Optimized Class-E Rf Power Amplifier Design In Bulk Cmos, Tao Wang

Electrical Engineering Theses - Archive

The telecommunication market calls for the integration of complicated wireless applications. To build RF power amplifiers in CMOS remains challenging due to the nonideal effects in CMOS. The aim of this thesis is to provide an optimized yet explicit design method for the Class-E amplifiers in CMOS. Taking the finite DC feed inductor into consideration, a simple but accurate numerical design method is proposed by applying polynomial interpolation. Combining with a practical design stategy for nonideal transistors of finite conductance and parasitic capacitances, a two-staged Class-E power amplifier is implemented in 0.18um CMOS. The simulation results show that this power …

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Detection Of Positive Cancer Margins Intra-Operatively During Nephrectomy And Prostatectomy Using Optical Reflectance Spectroscopy, Disha Laxman Peswani Aug 2007

Detection Of Positive Cancer Margins Intra-Operatively During Nephrectomy And Prostatectomy Using Optical Reflectance Spectroscopy, Disha Laxman Peswani

Bioengineering Theses - Archive

In recent years optical spectroscopies have become the basis for popular research activity directed towards the development of novel, noninvasive technologies for tissue diagnostics. The motivation for my research was to eliminate the need for surgical removal of tissue samples for biopsy and histology. With the help of an optical probe placed on or near the surface of the tissue, Near Infrared (NIR) spectroscopy can provide diagnostic signatures, non-invasively and in real time. While the ultimate goal vi is the elimination of the need to remove tissue samples, this technology can also be used to provide additional guidance during laparoscopic …

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Foreign Body Reactions To Neural Implants In The Brain, Parisa Lotfi Aug 2007

Foreign Body Reactions To Neural Implants In The Brain, Parisa Lotfi

Bioengineering Theses - Archive

Neural implants have been used and studied for many decades. They are applied to record neural signals or to locally deliver drugs. Unfortunately, foreign body reaction and accompanied glial scar formation often lead to implant failure. The lack of knowledge about the molecular mechanism governing foreign body reactions in the brain significantly hinders the development of brain implantable devices with improved safety and biocompatibility. To study the immune responses to brain implants, a novel animal model has been developed and used for the following investigation. Our studies have established cell recruitment time courses of astrocytes, microglial cells, lymphocytes, monocytes and …

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Functionalized Nanoparticles For The Selective Killing Of Cancer Cells, Paul Todd Thevenot Aug 2007

Functionalized Nanoparticles For The Selective Killing Of Cancer Cells, Paul Todd Thevenot

Bioengineering Theses - Archive

The use of nanoparticles for cancer imaging and drug delivery has produced some success in improving the efficacy and safety of cancer chemotherapy. It is generally believed that the efficiency of nanoparticle-based cancer therapy would be greatly improved if such particles could be designed to directly interact with and eradicate tumor. Many recent studies have revealed that surface functionality plays an important role in particle:cell interactions. Using titanium dioxide (TiO2) nanoparticles (21 nm diameter) as test subjects, nanoparticles with different functional groups, hydroxyl (-OH), amine (-NH2), and carboxyl (-COOH) were produced and used in this investigation. An in vitro cell …

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Cytotoxic Evaluation And Factorial Analysis Of 3d Photopolymerizable Thermoresponsive Composite Nanoparticle Hydrogels For Controlled Drug Delivery In Restenosis And Wound Healing, Abhimanyu Rajaram Sabnis Aug 2007

Cytotoxic Evaluation And Factorial Analysis Of 3d Photopolymerizable Thermoresponsive Composite Nanoparticle Hydrogels For Controlled Drug Delivery In Restenosis And Wound Healing, Abhimanyu Rajaram Sabnis

Bioengineering Theses - Archive

To develop a smart drug delivery system for restenosis and wound healing applications, we investigated photopolymerizable composite nanoparticle hydrogels which can release the drug in a temperature-responsive manner. Our novel system consisting of thermoresponsive poly(N-isopropylacrylamide-co-acrylamide) (PNIPA-AAm) nanoparticles and poly(ethylene glycol) diacrylate (PEGDA) as photo cross-linker can be formed in situ in presence of ultraviolet (UV) light and Irgacure 2959 photoinitiator (PI). The main aims of this project were to investigate the system cytotoxicity and optimize drug release characteristics by performing biocompatibility and factorial analysis studies, respectively. We evaluated the cell survival of human vascular smooth muscle cells and NIH/3T3 fibroblasts …

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Investigation Of Brain Activities Using Two State-Of-The-Art Diffuse Optical Imagers, Suresh Prajapati Aug 2007

Investigation Of Brain Activities Using Two State-Of-The-Art Diffuse Optical Imagers, Suresh Prajapati

Bioengineering Theses - Archive

Near-Infrared Spectroscopy (NIRS) and diffuse optical imaging (DOI) are increasingly used to detect hemodynamic changes in the cerebral cortex induced by brain activity. The new commercially available DOI systems CW5 and DYNOT have large number of sources and detectors; by arranging them in specific patterns, one can cover most of the adult head. This study is a preliminary step in understanding CW5 and DYNOT and exploring their capabilities for various purposes. My work is divided in to three major parts. The first goal of this study was to study changes in hemodynamic response of brain during Breath holding, using both …

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Gas Permeation Through Nanoporous Polycarbonate Track- Etched Membranes: Pulsed Plasma Polymerization Of Thin Coatings To Modulate Gas Permeability, Christopher Lewis Chapman Aug 2007

Gas Permeation Through Nanoporous Polycarbonate Track- Etched Membranes: Pulsed Plasma Polymerization Of Thin Coatings To Modulate Gas Permeability, Christopher Lewis Chapman

Bioengineering Theses - Archive

Polycarbonate track-etched membranes (PCTE) of 50nm and 100nm pore size, precoated with Poly Vinyl Pyrrolidone (PVP), were surface treated with either Vinyl Acetic acid (VAA) or Perfluorohexane (C6F14) using a low duty cycle pulsed plasma polymerization technique. The effects of this surface treatment on gas permeation properties of the PCTE were addressed. Plasma coating thickness was controllably varied and resulted in gradual reduction of O2 and CO2 permeability as thickness increased from 10nm to 100nm. Plasma coating material, permeant gas, membrane pore size, and crosslink density were also varied in order to gain insight into the permeation properties of the …

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Genetic Determinants Of Reproductive Isolation In Xenopus, John Malone Aug 2007

Genetic Determinants Of Reproductive Isolation In Xenopus, John Malone

Biology Dissertations - Archive

Haldane's rule states that in F1 interspecific hybrids the heterogametic sex (XY or ZW) suffers the most dysfunctional effects of hybridization. Frogs of the genus Xenopus have ZW sex determination yet hybrid males are completely sterile and hybrid females are fertile, a pattern exactly opposite of Haldane's rule. One of the most compelling hypotheses to explain this pattern is faster male evolution. The faster male evolution hypothesis suggests that hybrid male sterility is more common than hybrid female sterility because of faster divergence of male reproductive genes (due to sexual selection), or inherent sensitivity with the process of spermatogenesis. This …

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Monte Carlo Analysis Of Refuge Site Selection: Statistical Properties And An Empirical Example, Anna Michelle Lawing Aug 2007

Monte Carlo Analysis Of Refuge Site Selection: Statistical Properties And An Empirical Example, Anna Michelle Lawing

Biology Theses - Archive

The Monte Carlo method can be a useful technique providing information on central tendencies and tolerance for selection data. There are many statistical hypothesis tests that are employed in selection studies, but most require the data are normally distributed to adhere to the null hypothesis based on a normal distribution. Monte Carlo methods build a null distribution to test hypotheses based on available conditions and therefore do not require distributions of data to be normal. A Monte Carlo is also an extremely flexible technique and can be designed to test hypotheses for any particular experimental design. I designed a Monte …

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Integrated Nurse Staffing And Assignment Under Uncertainty, Prattana Punnakitikashem Aug 2007

Integrated Nurse Staffing And Assignment Under Uncertainty, Prattana Punnakitikashem

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

One of the major problems in the United States health care system is a shortage of nurses. Baby boomers and an increasing elderly population are the main reasons for a rapidly growing demand for nurses. Besides the decline in enrollments in registered nurse degree programs, many nurses have suffered from work burnout. High workloads and undesirable schedules are two major issues that cause nurses' job dissatisfaction. As a result, nurses plan to leave their jobs causing low retention and low entering rates. One consequence of the shortage is that excessive workload on nurses decreases the quality of patient care. Many …

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A Data-Integrated Simulation-Based Optimization Approach For Nurse-Patient Assignment, Duraikannan Sundaramoorthi Aug 2007

A Data-Integrated Simulation-Based Optimization Approach For Nurse-Patient Assignment, Duraikannan Sundaramoorthi

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

This research develops a novel data-integrated simulation to evaluate nurse-patient assignments (SIMNA) based on a real data set provided by Baylor Regional Medical Center (Baylor) in Grapevine, Texas. Tree-based models and kernel density estimation were utilized to extract important knowledge from the data for the simulation. Classification and Regression Tree models, data mining tools for prediction and classification, were used to develop five tree structures: (a) four classification trees, from which transition probabilities for nurse movements are determined; and (b) a regression tree, from which the amount of time a nurse spends in a location is predicted based on factors …

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Effects Of Experiential Learning On Face To Face And Multimedia Learning Environments In The Acquisition Of Active Listening Skills, Juan Enrique Huerta Wong Aug 2007

Effects Of Experiential Learning On Face To Face And Multimedia Learning Environments In The Acquisition Of Active Listening Skills, Juan Enrique Huerta Wong

Social Work Dissertations - Archive

Comparison studies between Technology or Multimedia Learning Environments and Face-to-Face (F2F) Learning Environments in social work education usually show that technology works as well as F2F environments. However, they also suggest they are not interchangeable, but are dependent upon educational approaches. Otherwise, experiential learning as a main educational approach has been adopted from Council on Social Work Education (CSWE) guidelines without strong evidence of its effectiveness. A 2X2 Nonrandomized Multiple Comparison Groups Design with pretest from each group evaluates the effectiveness of two different Learning Environments (multimedia versus F2F) and two different Teaching Techniques (experiential versus exposure plus discussions) in …

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Chronic Widespread Pain In Patients With Occupational Spinal Disorders: Prevalence, Psychiatric Comorbidity, And Association With One-Year Treatment Outcomes, Benjamin Lee Towns Aug 2007

Chronic Widespread Pain In Patients With Occupational Spinal Disorders: Prevalence, Psychiatric Comorbidity, And Association With One-Year Treatment Outcomes, Benjamin Lee Towns

Psychology Theses - Archive

Chronic Widespread Pain (CWP) is estimated to affect 4.1% - 13.5% of the general population. Compared to those who are pain-free or have localized pain, those with widespread body pain have been found to higher rates of psychiatric disorder, greater pain intensity, and greater disability. Treatment programs for CWP patients often have high drop-out rates and have only achieved modest results. The present study sought to compare demographic characteristics, psychiatric comorbidity, and one-year treatment outcomes of patients with chronic disabling occupational spinal disorers (CDOSDs) meeting criteria for CWP to those who fail to meet criteria. Within this CDOSD cohort (n …

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Cognitive Independence And Cohesion In Decision-Making Groups, Kelly A. Trindel Aug 2007

Cognitive Independence And Cohesion In Decision-Making Groups, Kelly A. Trindel

Psychology Dissertations - Archive

Cognitive Independence (CI) can be defined as the tendency to form opinions and make decisions based on personal knowledge as well as additional information that appears to be valid and factual. CI implies a tendency away from normative influence and toward informational influence. In this project CI is investigated in multiple forms in terms of its effects on group decision-making. Over the course of four studies the construct is identified and defined, a scale is designed to measure it and its predictive power in state and trait variable forms are investigated on the Hidden Profile group-decision-making task (Stasser & Titus, …

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Evaluation And Applications Of Gas Sensors, Hung Viet Cao Aug 2007

Evaluation And Applications Of Gas Sensors, Hung Viet Cao

Electrical Engineering Theses - Archive

Gas sensors are used widely for environmental and biomedical uses. This work focuses on verifying specifications of commercial-off-the-shelf (COTS) gas sensors and their particular applications. The first chapter in this thesis gives a literature review on gas sensors, especially metal-oxide based sensors and their advantages. The second chapter focuses on evaluation of COTS NO2 sensors. The purpose is to establish a characterization method to evaluate gas sensors. I have evaluated three COTS metal-oxide based NO2 sensors and a COTS electrochemical sensor for comparison. Four different tests have been implemented to investigate the sensitivity, humidity effects, temperature effects, and selectivity for …

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Design And Simulation Of An Accurate Breast Biopsy System, Sumit Tandon Aug 2007

Design And Simulation Of An Accurate Breast Biopsy System, Sumit Tandon

Electrical Engineering Theses - Archive

Core needle biopsy is a non-invasive technique for confirming breast and prostate cancer. Over the years, several non-real time image guided systems have been developed to guide the needle to the target lesion/tumor. Frequently used methods are those employing x-ray, ultrasound, MRI or x-ray fluoroscopy to guide the needle during biopsy. However, these methods suffer from the disadvantages that they are non-real time or the imaging technique is two dimensional or ionizing. Our broad objective is to develop a visually guided, haptic assisted breast biopsy system (henceforth called ViHAB) using real time 3D ultrasound imaging and haptic guidance. The system …

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Airport Security: Study Of Students' Perception And Knowledge Of The Selection Of Airline Passengers For Personal Searches, Esthela Cabrera Hernandez Aug 2007

Airport Security: Study Of Students' Perception And Knowledge Of The Selection Of Airline Passengers For Personal Searches, Esthela Cabrera Hernandez

Criminology & Criminal Justice Theses - Archive

The aim of this study was to analyze and identify the perception and kowledge of the criteria used to select airport passengers for personal searches. The study was carried out via self-administered surveys. The collected data derived from the sample of undergraduate students at the University of Texas at Arlington. The study revealed statistically significant diferences in percepcion and knowledge between male and female students. The findings of this study suggest that undergraduate students perceived that African Americans and Hispanics are more likely to be searched at airports than Whites. It was also perceived that males are more likely to …

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"Commies And Queers": Narratives That Supported The Lavender Scare, Holly S. Heatley Aug 2007

"Commies And Queers": Narratives That Supported The Lavender Scare, Holly S. Heatley

History Theses - Archive

In the early 1950s, the perceived threat of communists and homosexuals loomed large over the United States. The U.S. press presented narratives that portrayed communists and homosexuals in remarkably similar language that easily merged. The U.S. public viewed the two groups as equal in status, kind, and objective. The twin menaces reinforced one another and elicited an equivalent response. These narratives and the perceptions they fostered set the stage for the purge of homosexuals from the federal government known as the Lavender Scare. While the Red Scare and Lavender Scare were originally intertwined, legislators and the federal security apparatus continued …

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Building Energy-Efficient Broadcast Trees Using A Genetic Algorithm In Wireless Sensor Networks, Min Kyung An Aug 2007

Building Energy-Efficient Broadcast Trees Using A Genetic Algorithm In Wireless Sensor Networks, Min Kyung An

Computer Science and Engineering Theses - Archive

In wireless broadcast environment, data can be transmitted to several nodes by a single transmission. The nodes in that environment have limited energy resources; therefore we need to reduce the energy consumption when they broadcast data to all nodes to prolong the lifetime of the networks. We call this problem the MPB (minimum power broadcast) problem, and solving the problem has been shown to be an NP-Complete problem [2], [11]. We focus on finding 'near-optimal' solutions for the problem. An algorithm for constructing the minimum power broadcast trees, named BIP (broadcast incremental power) algorithm, was first proposed by Wieselthier et …

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System And Method For The Pooling Of Sterile Product, David A. Edelen Aug 2007

System And Method For The Pooling Of Sterile Product, David A. Edelen

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

This dissertation defines an automated system and method for removing the tops from individual sealed bottles and pooling the small volumes of liquid contained in each bottle together in a collection container while maintaining the sterility of the product. This research further applied system development and process improvement methodology. More particularly, this research solved a previously unsolved problem through the unique research and development, and application of ultrasonic technology, to mitigate both product and personnel risk, and provide process improvement, as associated with the aseptic process for the pooling of sterile product.

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M-Infosift : A Graph-Based Approach For Multiclass Document Classification, Aravind Venkatachalam Aug 2007

M-Infosift : A Graph-Based Approach For Multiclass Document Classification, Aravind Venkatachalam

Computer Science and Engineering Theses - Archive

With the increase in the amount of data being introduced into the Internet on a daily basis, the problem of managing large amount of data is an unavoidable problem. The area of document classification has been examined, explored and experimented as a technique for organizing and managing vast repositories of electronic documents such as emails, text and web pages. Over the past decade, several approaches such as machine learning, data mining, information retrieval and others have been proposed for addressing this problem of classifying electronic documents. While a majority of these techniques rely on extracting high-frequency keywords, they ignore the …

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Polymer-Based Rf Mems Devices, Jianqun Wang Aug 2007

Polymer-Based Rf Mems Devices, Jianqun Wang

Electrical Engineering Dissertations - Archive

The radio frequency micro-electro-mechanical system (RF MEMS) technology is rapidly transitioning from the research stage to commercial applications. Reducing material and fabrication costs, realizing IC compatibility, and improving the RF performance have been main focal points of many recent works. In this dissertation, we target at developing a RF MEMS methodology which realizes CMOS compatibility, cost effectiveness and high performance at the same time. The current RF MEMS devices are mostly constructed on quartz and III-V compound materials to achieve low RF losses. These approaches proved to have excellent RF performance. However these materials are expensive and unable to be …

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Resource Adaptive Agent Based Fault Tolerant Architecture, Shreyas Shetty Aug 2007

Resource Adaptive Agent Based Fault Tolerant Architecture, Shreyas Shetty

Computer Science and Engineering Theses - Archive

Pervasive environment consists of increasing number of mobile, tiny and heterogeneous devices communicating through interconnected network. As ubiquitous computing has seeped into various aspects of everyday life, there has been an increasing demand for dependable systems. However providing reliability demands fault tolerance mechanisms that require substantial time and resources. The dynamic nature and the uncertainty associated with pervasive systems coupled with the energy constraints of the devices involved makes fault tolerance a challenging task. In general, the techniques used to provide fault-tolerance are based on having redundancy and duplication of the user tasks. However the additional cost and the low …

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Model Reference Adaptive Control Using Stacked Identifiers, Weider Chung Aug 2007

Model Reference Adaptive Control Using Stacked Identifiers, Weider Chung

Electrical Engineering Dissertations - Archive

Model reference adaptive control is a major design method for controlling plants with uncertain parameters. The primary objective of this dissertation is to develop a new design approach for the model reference adaptive control of a single-input single-output linear time-invariant plant. The proposed method, called the "Model reference adaptive control using stacked identifiers," uses a stacked identifier structure that is new to the field of adaptive control. The goal is to make the output of the plant asymptotically track the output of the first identifier, and then driving the output of the first identifier to track that of the second …

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Incremental Retrieval And Ranking Of Complex Patterns From Text Repositiories, Jayakrishna Thathireddy Aug 2007

Incremental Retrieval And Ranking Of Complex Patterns From Text Repositiories, Jayakrishna Thathireddy

Computer Science and Engineering Theses - Archive

As the volume of information accessible via the electronic medium (such as the Internet) is staggeringly large and growing rapidly, users have to sift through vast reservoirs of information to retrieve relevant data of their choice. It has been estimated that, the Internet consists of 2.5 billion unique, publicly accessible web-pages and this figure is growing at an alarming rate of 7.3 million pages per day. Currently, the only way to wade through such colossal information is by using search engines (such as Google, Live, Yahoo, etc.). Although the popularity of search engines has increased manifold due to -- simplicity …

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Top K Query Processing In Distributed Database, Amrita Tamrakar Aug 2007

Top K Query Processing In Distributed Database, Amrita Tamrakar

Computer Science and Engineering Theses - Archive

Today's data is rarely stored in centralized location due to the enormous amount of information that needs to be stored and also to increase reliability, availability and performance of the system. Same data is stored in different format into different company's database as well as they may be partitioned or replicated. We consider various scenarios of distributed database such as horizontal, vertical fragmentation and attribute overlapping. Allowing access to integrated information from these multiple datasets can provide accurate and wholesome information to the end-user. We research on efficient querying to these distributed databases to get top k elements matching the …

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Sequence Alignment Editor - A New Tool To Assist With Inferring Phylogenetic And Functional Relationships In Biological Data, Ramya Raghukumar Aug 2007

Sequence Alignment Editor - A New Tool To Assist With Inferring Phylogenetic And Functional Relationships In Biological Data, Ramya Raghukumar

Computer Science and Engineering Theses - Archive

Biologists study evolution, discover functional and structural information in genomic or protein data through the extensive use of sequence alignments. It is very difficult to manually align long regions, so development of methods for this task continues to be an active area of research. Alignment construction algorithms, based on dynamic programming, approach the problem from a mathematical perspective. The optimal alignment is computed relative to a scoring scheme. The resulting layout is guaranteed to be mathematically optimal, though not necessarily biologically meaningful. Sequence alignments usually account only for single letter substitutions and relatively short indels, representing the latter as gaps. …

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1/F Noise In Hafnium Based High-K Gate Dielectric Mosfets And A Review Of Modeling, Siva Prasad Devireddy Aug 2007

1/F Noise In Hafnium Based High-K Gate Dielectric Mosfets And A Review Of Modeling, Siva Prasad Devireddy

Electrical Engineering Dissertations - Archive

For next generation MOSFETs, the constant field scaling rule dictates a reduction in the gate oxide thickness among other parameters. Consequently, gate leakage current becomes a serious issue with very thin SiO2 that is conventionally used as gate dielectric since it is the native oxide for Si substrate. This has driven an industry wide search for suitable alternate 'high-k' gate dielectric that has a high value of relative permittivity compared to SiO2 thereby presenting a physically thicker barrier for tunneling carriers while providing a high gate capacitance. Consequently, it is essential to study the properties of these novel materials and …

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Performance Analysis Of Caching Effect On Real Time Packet Processing In A Multi-Threaded Processor, Miao Ju Aug 2007

Performance Analysis Of Caching Effect On Real Time Packet Processing In A Multi-Threaded Processor, Miao Ju

Computer Science and Engineering Theses - Archive

Caching has been time proven to be a very effective technique to improve memory access speed and average performance for general processors. Based on the real-world trace simulation, earlier research showed that cache can help improve the route lookup and packet classification performance in a Network Processor (NP). However, the existing studies did not take the packet delay/loss constraints into account. As a result, how effective the caching technique is, in dealing with traffic under stringent delay/loss constraints (as is the case for router interface using an NP for packet processing), is still an open issue. In this thesis, we …

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Rate Control Algorithms For Ieee 802.11 Wireless Networks, Bodhisatwa Chakravarty Aug 2007

Rate Control Algorithms For Ieee 802.11 Wireless Networks, Bodhisatwa Chakravarty

Computer Science and Engineering Theses - Archive

This thesis evaluates software driven rate selection algorithms used in IEEE 802.11 wireless network interface cards. The motive of the bit-rate selection techniques is to optimize the throughput over the wireless network out of the many rates that are supported by the IEEE 802.11 link. The decision to switch from one rate to another with the changing link conditions to optimize the throughput is the primary focus of the bit-rate selection algorithms. Due to the uncertainty in the channel quality, it is a challenge to make the correct decision so as to minimize the wastage of network resources and achieve …

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