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Delay Tolerant Lazy Release Consistency For Distributed Shared Memory In Opportunistic Networks, Chance Ray Eary Jan 2011

Delay Tolerant Lazy Release Consistency For Distributed Shared Memory In Opportunistic Networks, Chance Ray Eary

Computer Science and Engineering Theses - Archive

Opportunistic networking (ON), a concept which allows a mobile wireless device to dynamically interact with other wireless devices in its immediate vicinity, is a field with great potential to improve the utility of itinerant computational platforms. While ONs increase a device's ability to interact with its peers, the fleeting and intermittent connections between devices make many traditional computer collaboration paradigms, such as distributed shared memory (DSM), virtually untenable. DSM systems, developed for traditional networks, rely on relatively stable, consistent connections among participating nodes. In an ON, connectivity among nodes is distributed in time and space making it useful for delay …

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The Design Of Cmos Impulse Generators For Ultra-Wideband Communication And Radar Systems, Ju-Ching Li Jan 2011

The Design Of Cmos Impulse Generators For Ultra-Wideband Communication And Radar Systems, Ju-Ching Li

Electrical Engineering Dissertations - Archive

Impulse generators play an important role in the ultra-wideband (UWB) systems. Particularly in the transmitter, impulse generator performs an interface between input data and the antenna determining the overall performance of the transmitter. After the federal communication commission (FCC) revised the rules for UWB systems usages, the design of impulse generators has been pursued and yet challenging especially using CMOS technology. In this dissertation, three impulse generators are presented with analytical explanations, simulations, and measurements. First, the design and simulation of an impulse generator using TSMC 0.18 ìm CMOS technology is presented. The operating frequency band of the impulse generator …

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Radar Sensor Networks: Waveform Design, Mimo And Compressive Sensing, Lei Xu Jan 2011

Radar Sensor Networks: Waveform Design, Mimo And Compressive Sensing, Lei Xu

Electrical Engineering Dissertations - Archive

In this dissertation, we have studied totally eight topics which are focused on but not limited to radar sensor networks (RSN) from a signal processing perspective. We propose the definitions of ZCZ/LCZ (Zero Correlation Zone/Low Correlation Zone) sequence-pair sets, provided three methods to construct optimized optimized punctured LCZ/ZCZ sequence-pair sets and study their properties in chapter 2 and 3. We further investigate the waveform design problem for radar system, radar sensor network, sonar sensor network and MIMO radar system from chapter 4 to chapter 7. In addition, we study radar sensor network from the view of information theory in chapter …

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Numerical Modeling Of Microwave Emission From Irregular Layer, Luis Manuel Camacho-Velazquez Jan 2011

Numerical Modeling Of Microwave Emission From Irregular Layer, Luis Manuel Camacho-Velazquez

Electrical Engineering Dissertations - Archive

A numerical approach to model the microwave emission from an irregular layer is developed. The phase matrix of the layer components as well as the emission characteristics are estimated using a numerical approach, namely the Finite-Difference Time-Domain (FDTD) method. The phase matrix is then integrated into a layer model that accounts for the scattering between the layer and ground, using the radiative transfer theory. The effects of interface roughness on emission are incorporated into the model through the surface phase matrices, which are computed using the Integral Equation Model (IEM).The validity of the phase matrices computation is tested against theoretical …

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The Complex Gaussian Scale Mixtures Of Complex Wavelet Coefficients And Applications, Yothin Rakvongthai Jan 2011

The Complex Gaussian Scale Mixtures Of Complex Wavelet Coefficients And Applications, Yothin Rakvongthai

Electrical Engineering Dissertations - Archive

In this thesis, the complex Gaussian scale mixture (CGSM), which is an extension of the Gaussian scale mixture (GSM) for real-valued random variables to the complex case, is presented to model the complex wavelet coefficients. Along with some related propositions and miscellaneous results, the probability density functions (pdf) of the magnitude and phase of the complex random variable are presented. Specifically, the closed forms of the magnitude pdf for the case of complex generalized Gaussian distribution (CGGD) and the phase pdf for the general case are presented. Subsequently, the pdf of the relative phase is derived.Moreover, parameter estimation methods in …

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Sybil Defense For Online Social Networks Using Partial Graph Information, Vritant Naresh Jain Jan 2011

Sybil Defense For Online Social Networks Using Partial Graph Information, Vritant Naresh Jain

Computer Science and Engineering Theses - Archive

Online social networks (OSNs) today are proprietary, in the sense that communication between users requires the users to be part of the same OSN. This raises privacy issues and reliability concerns among users, and calls for an open, interoperable, and distributed OSN infrastructure that is similar to email and would link different OSNs together. Any decentralized system, however, is vulnerable to Sybil attacks, in which an attacker claims multiple identities, called Sybils, to overwhelm the OSNs and defeat standard techniques used to protect against attacks such as message spam. The state of the art defense against these attacks is SybilInfer, …

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Miniature Wireless Gastrostimulator, Sanchali Deb Jan 2011

Miniature Wireless Gastrostimulator, Sanchali Deb

Electrical Engineering Dissertations - Archive

Gastroparesis is a common disorder caused to patients suffering from diabetes, cancer and Parkinson's disease. Gastric electrical stimulation (GES) has attracted significant attention in the treatment for Gastroparesis. GES inflicts electrical pulses to the stomach tissues to help regain normal motility and hence reduces Gastroparesis symptoms like vomiting, nausea, abdominal bloating etc. Conventional gastric stimulator needs a long surgery to be implanted and it is a big pacemaker like device that runs by a non-rechargeable battery. It has to be replaced once the battery gets exhausted. Hence another round of surgery is done when these devices are needed to be …

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Performance Tuning Of An Embedded Template Analysis Tool, Ashwin Arikere Jan 2011

Performance Tuning Of An Embedded Template Analysis Tool, Ashwin Arikere

Computer Science and Engineering Theses - Archive

As multi core processors become ubiquitous, programs must be designed to utilize the additional power at their disposal. Extracting maximum performance out of these processors requires utilizing latest parallel programming techniques as well as using the latest tools available to increase performance. This thesis delves into enhancing performance of existing programs by applying parallel techniques, utilizing performance analyzers and various other tools developed specially for multi-core system programming. We discuss these techniques and tools and also demonstrate how a Template Analysis program was modified to take advantage of the additional power a multi-core machine has over single core machines to …

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Automatic Discovery Of Significant Events From Databases, Avinash Shankar Bharadwaj Jan 2011

Automatic Discovery Of Significant Events From Databases, Avinash Shankar Bharadwaj

Computer Science and Engineering Theses - Archive

The advent of the internet has caused enormous amounts of data available online causing many significant facts to be hidden within this data. Searching for a significant fact within these large datasets is a query intensive process involving large amounts of queries which needs to be executed hence slowing the process of finding the significant facts from a large dataset. In this thesis, a novel approach has been designed exploiting the mathematical characteristics of the data present in the dataset to reduce the number of queries on the dataset. A two phased approach is considered for making fact finding more …

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Localization Of Short Circuit Faults In The Power Distribution Networks, Omkar Deepak Limaye Jan 2011

Localization Of Short Circuit Faults In The Power Distribution Networks, Omkar Deepak Limaye

Electrical Engineering Theses - Archive

This thesis summarizes the research efforts on localizing short-circuit faults in power distribution networks. Specifically, an experimental testbed is constructed to emulate realistic power distribution networks; various short-circuit faults are artificially created in the testbed; voltages/currents are measured over the testbed; and finally, fault localization is achieved by analyzing the measurement data.Two types of power distribution networks are analyzed: serial/radial and grid/mesh networks. In the serial network, a scheme based on terminal voltage and current measurements is developed. Two voltage profiles, namely "forward voltage profile" and "backward voltage profile," are plotted and their intersection is estimated as the fault location. …

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Bridge Monitoring System Using Embedded Computer Vision, Kenan Modi Jan 2011

Bridge Monitoring System Using Embedded Computer Vision, Kenan Modi

Electrical Engineering Theses - Archive

The bridges and overpass are integral part of road network. These structures deteriorate the moment the construction is over. The factors of deterioration are impact loads of vehicles, natural factors such as wind, rain, earthquake, floods, etc. These deterioration leads to structural failures. In order to prevent failures these structure should be periodically monitored and maintained. In this research project a novel method for early detection of bridge failure using computer vision application and 3D road profiling system is proposed. The objective of this research work to check the feasibility of this bridge monitoring system for any structural movement detection. …

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Development Of Prosthetic Skin, Rohit Kilaru Jan 2011

Development Of Prosthetic Skin, Rohit Kilaru

Electrical Engineering Theses - Archive

The objective of this research was to embed tactile sensors in polyimides. This novel method could be utilized to realize prosthetic skin for sensing different kinds of mechanical stimuli. Tactile sensors have an increasing demand in medical sectors: upper and lower-limb prosthetics and in the industrial sectors: robot end-effectors, grippers and manipulators. The sensors developed are targeted for prosthetic arm tactile sensing applications. Current work presents piezoresistive differential pressure sensors fabricated on flexible polyimide film or substrate.A unique technique to bond a flexible superstrate polyimide layer to a MEMS tactile sensor array is presented in this thesis. The sensor is …

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Investigating The Implementation Of Usaf Damage Tolerant Risk Analysis With A Structural Health Monitoring System, Jeffrey Scott Tippey Jan 2011

Investigating The Implementation Of Usaf Damage Tolerant Risk Analysis With A Structural Health Monitoring System, Jeffrey Scott Tippey

Electrical Engineering Theses - Archive

The recent improvements in micro fabrication, power management, and distributed sensor networks have made Structural Health Monitoring (SHM) an appealing solution for decreasing costs, decreasing risk of catastrophic failure, and improving overall aircraft health and maintenance (Mukkamala, 2000). A SHM system uses non-destructive inspection (NDI) to provide on-demand updates on the health of a structure, such that the integrity of the structure can be quantified and accounted for (Achenback, 2009). In order to provide an accurate representation of a structure's health, a distributed network of sensors must work in unison to detect a distribution of cracks and damage present on …

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Temperature And Frequency Dependence Of Thermal Impedance In Dielectrically Isolated Sige Hbts, Valay Dineshbhai Shah Jan 2011

Temperature And Frequency Dependence Of Thermal Impedance In Dielectrically Isolated Sige Hbts, Valay Dineshbhai Shah

Electrical Engineering Theses - Archive

Silicon Germanium (SiGe) heterojunction bipolar transistors (HBTs) have been designed to cater the demand of high speed circuits having applications in wireless and optical communication. Due to higher cut-off frequencies and high speed applications, self heating plays a significant role in the performance of SiGe HBTs. This thesis paper does an extensive analysis on the effect of self heating and used different DC, time domain and frequency domain methods to extract the self heating parameters thermal resistance (Rth) and thermal capacitance (Cth). The VBIC (Vertical Bipolar Inter Company) model is used for all the simulations. Simulations are performed using ICCAP …

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Scalable Parallel Processing Of Multi-Objective Optimized Dna Sequence Assembly, Munib Ahmed Jan 2011

Scalable Parallel Processing Of Multi-Objective Optimized Dna Sequence Assembly, Munib Ahmed

Computer Science and Engineering Dissertations - Archive

Bioinformatics is an emerging branch of science where issues pertaining to molecular biology are evaluated and resolved by leveraging the techniques and algorithms devised in the field of computer science. Most of these issues are due to the enormous amount of data and the computational complexity involved in generating expeditious and qualitatively viable solutions. This poses a challenge to the algorithm developers who must strive to achieve multiple conflicting objectives of processing very large dataset with the highest accuracy possible while keeping the execution time to a minimum. Genome assembly is one such problem in bioinformatics where a DNA sequence …

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Accurate And Cost Efficient Object Localization Using Passive Uhf Rfid, Jae Sung Choi Jan 2011

Accurate And Cost Efficient Object Localization Using Passive Uhf Rfid, Jae Sung Choi

Computer Science and Engineering Dissertations - Archive

In a smart environment, accurate locations of objects are a fundamental and critical issue. To achieve this goal, we present several methods based on passive far-field UHF RFID technologies, which can satisfy accuracy, robustness and reliability, cost efficiency, simplicity, compatibility, and scalability. Our research overcomes several negative characteristics of the use of cost efficient passive UHF RFID. Our research has several important contributions.First, we study the causes of the problems of using passive UHF RFID in localization, with detailed empirical results, and then, present the impacts of the causes on existing localization techniques such as KNN. Second, we present a …

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Comparison Of Brain Activity In The Prefrontal Cortex During Digit Span Task Between Student Veterans With Post Traumatic Stress Disorder And Controls Using Functional Near Infrared Spectroscopy, Bejoy Mathai Jan 2011

Comparison Of Brain Activity In The Prefrontal Cortex During Digit Span Task Between Student Veterans With Post Traumatic Stress Disorder And Controls Using Functional Near Infrared Spectroscopy, Bejoy Mathai

Bioengineering Theses - Archive

Near Infrared Spectroscopy (NIRS) is an optical non-invasive imaging technique which makes use of infrared light at particular wavelengths to measure the changes in concentrations of oxygenated blood haemoglobin (HbO) as well as the deoxygenated blood haemoglobin (HbR). Making use of this technique to acquire measurements during different functional activities subcategorises it into the novel and fast developing field of Functional Near Infrared Spectroscopy (fNIRS). In my study I have made use of this novel imaging technique to study the pre-frontal cortex while the subject performs the functional task of digit span task consisting of the forward digit span and …

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Flexural Behavior Of Steel Fiber Reinforced Prestressed Concrete Beams And Double Punch Test For Fiber Reinforced Concrete, Netra Bahadur Karki Jan 2011

Flexural Behavior Of Steel Fiber Reinforced Prestressed Concrete Beams And Double Punch Test For Fiber Reinforced Concrete, Netra Bahadur Karki

Civil Engineering Dissertations - Archive

Steel fibers have widely been used in the past to reinforce brittle materials in many nonstructural applications such as pavement, tunneling lining, etc. On the basis of numerous previous studies, ACI 318-11 [2011] has recently accepted steel fiber as a minimum shear reinforcement replacement with minimum 0.75% volume fraction for both reinforced concrete and prestressed concrete members. However, not much previous research has talked about the flexural behavior of fiber reinforced concrete (FRC). As per ACI 318-11 for tension-controlled sections, the net tensile strains in the outermost layer of steel, εt, should be greater than or equal to 0.005 and …

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Evaluation Of Training Needs For Building Information Modeling (Bim), German Pena Jan 2011

Evaluation Of Training Needs For Building Information Modeling (Bim), German Pena

Civil Engineering Theses - Archive

The basic premise of Building Information Modeling (BIM) is to use and share the digital model of a project as a source of information for all participants, in order to simulate and analyze potential problems during the project's life-cycle, from conception to operation. BIM is a relatively new technology praised by all participants in the Architecture-Engineering-Construction (AEC) industry for its innovative tools, and the promise of a high return of investment and productivity increase. The construction industry experimented little growth in productivity in the last decades, and is heavily relying on technology rather than intense labor in order to boost …

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Effect Of Pavement Type On Fuel Consumption In City Driving, Palinee Sumitsawan Jan 2011

Effect Of Pavement Type On Fuel Consumption In City Driving, Palinee Sumitsawan

Civil Engineering Dissertations - Archive

Vehicular fuel consumption and emissions are two increasingly important measures of effectiveness of sustainable transportation systems, particularly considering that mobile sources in the U.S. account for the largest consumption of energy and generation of air pollution. Improving the energy efficiency of the transportation sector including improving vehicle shape, weight, engine size, and tire quality could play a vital role in reducing fuel consumption and exhaust gas emissions. Pavement surface type and other surface characteristics such as skid resistance and roughness affect vehicular fuel consumption. The main objective of this study has been to investigate any differences that might exist in …

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Development Of A Model Of Productivity For Horizontal Directional Drilling (Hdd), Mohmd Sarireh Jan 2011

Development Of A Model Of Productivity For Horizontal Directional Drilling (Hdd), Mohmd Sarireh

Civil Engineering Dissertations - Archive

Horizontal Directional Drilling (HDD) is a growing method for installation of pipes in urban areas and where ever trenching is impossible or undesirable; such as in crossing rivers, lakes, and railways, and special areas such as airports. This technique utilizes downhole cutting heads to create a pilot borehole before it is enlarged with back reamers to allow pulling back of a product pipe. The utilization of HDD for the installation of underground infrastructure (i.e., water, oil and gas pipes, telecommunication, power conduits, in some cases gravity pipes, and so on), has shown a rapid growth compared to other trenchless technologies. …

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Impact Of Transit-Oriented Infrastructure Investments On Property Valuations, Francis Amodu Smith Jan 2011

Impact Of Transit-Oriented Infrastructure Investments On Property Valuations, Francis Amodu Smith

Civil Engineering Dissertations - Archive

The population explosion of the second half of the last century brought about increased human activity. Much of the attendant increased access to activities has been facilitated by the incredible technological advances in the automobile, which depends almost entirely on fossil fuels. Supplies of fossil fuel are limited and the automobile has led to urban sprawl, traffic congestion, and reduced quality to life in cities (1). This type of development is unsustainable. Transit-oriented development (TOD) is one of the neo-urbanism response instruments. The question is: "How well do these urban forms perform in North-Central Texas? In response, this study has …

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Nano-Modified Cement Composites And Its Applicability As Concrete Repair Material, Tanvir Manzur Jan 2011

Nano-Modified Cement Composites And Its Applicability As Concrete Repair Material, Tanvir Manzur

Civil Engineering Dissertations - Archive

Nanotechnology or Nano-science, considered the forth industrial revolution, has received considerable attention in the past decade. The physical properties of a nano-scaled material are entirely different than that of bulk materials. With the emerging nanotechnology, one can build material block atom by atom. Therefore, through nanotechnology it is possible to enhance and control the physical properties of materials to a great extent. Composites such as concrete materials have very high strength and Young's modulus but relatively low toughness and ductility due to their covalent bonding between atoms and lacking of slip systems in the crystal structures. However, the strength and …

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Multivariate Adaptive Regression Spline Based Framework For Statistically Parsimonious Adaptive Dynamic Programming, Subrat Sahu Jan 2011

Multivariate Adaptive Regression Spline Based Framework For Statistically Parsimonious Adaptive Dynamic Programming, Subrat Sahu

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

Central to Dynamic Programming (DP) is the `cost-to-go' or `future value' function, which is obtained via actually solving the Bellman's equation and central to Approximate Dynamic Programming (ADP) is the use of an approximation of the future value function. The exact DP algorithm seeks to compute and store a table consisting of one cost-to-go value for each point in the state space and its usefulness is limited by the curse of dimensionality, which renders the methodology computationally intractable in the face of real life problems with high dimensional state space and in the face of continuous state variables. ADP methodology …

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Parametric Analysis Of A Detonation-Type Turbofan, Yashwanth M. Swamy Jan 2011

Parametric Analysis Of A Detonation-Type Turbofan, Yashwanth M. Swamy

Mechanical and Aerospace Engineering Theses - Archive

A new type of turbofan which detonates a fuel-air mixture was theoretically found to perform better than a conventional turbofan. A continuous detonation process is described and considered inside the core of the turbofan. The detonation-type turbofan needs certain modifications to detonate the fuel-air mixture at the core of the turbofan, namely, an annular detonation chamber to achieve continuous detonation. A parametric analysis of the new detonation-type turbofan was developed and used to calculate the performance parameters.

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The Equivalence And Generalization Of Optimization Criteria, Surachai Charoensri Jan 2011

The Equivalence And Generalization Of Optimization Criteria, Surachai Charoensri

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

In this dissertation we first show that existing optimization criteria are equivalent to the maximization of a real-valued function in a one-dimensional Euclidean space. The criteria are said to be scalar equivalent. All solutions and only solutions to an optimization problem involving the original criterion can be obtained by scalarization without the typical convexity or concavity assumptions on the original objective functions and feasible region. Examples include Pareto (including the scalar case), satisficing, maximin, and cone-ordered optimization, as well as the more general notion of set-valued optimization in abstract spaces. Moreover, equivalences between various different optimization criteria are also established …

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Adaptive High Level Context Reasoning In Pervasive Environments, Bridget B. Beamon Jan 2011

Adaptive High Level Context Reasoning In Pervasive Environments, Bridget B. Beamon

Computer Science and Engineering Dissertations - Archive

It is hard to believe that the Internet is now in its adolescent stage. This information age is replete with communication capable, intelligent, sensor equipped devices. Social networks, web services, and global information repositories make a wealth of information available instantly. There exist endless possibilities for creating useable knowledge. Much of what is considered useable knowledge is not directly observable from low level sensory devices. Abstract situations, relationships and activities must be inferred using a variety of techniques that fuse information from multivariate data sources. We refer to this useable knowledge as high level context. Social, physiological, environmental, computational, activity, …

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Numerical Study Of Drop Formation From Dripping To Jetting, Allouah Kadjo Jan 2011

Numerical Study Of Drop Formation From Dripping To Jetting, Allouah Kadjo

Mechanical and Aerospace Engineering Theses - Archive

The formation of liquid droplet from a capillary tube has been examined using numerical simulations. The dimensions of the capillary tube and the flow velocity have been varied to observe the regimes of drop formation. There are three main regimes of drop formation, which are the periodic dripping, the dripping faucet and the jetting regimes. The mechanism of drop formation changes from one regime to another and involves different parameters. A particular emphasis has been placed on the velocity limits between the different regimes and the critical role played by instabilities in the generation of satellite drops. The algorithm used …

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Numerical Modeling Of A Parallel Plate Electrowetting-On-Dielectric (Ewod) Device, Kevin Tully Jan 2011

Numerical Modeling Of A Parallel Plate Electrowetting-On-Dielectric (Ewod) Device, Kevin Tully

Mechanical and Aerospace Engineering Theses - Archive

Numerical modeling and simulations have been performed in this study that focuses on modeling the fluid dynamics of an Electrowetting-on-Dielectric (EWOD) device. The case to be modeled in the present study is a droplet cutting problem where a droplet is sandwiched between two plates of Teflon and an electrical actuation will cause the droplet to cut or split into two smaller droplets. A finite difference method has been used to solve the Navier-Stokes equations, along with the continuity equation. An algorithm used for tracking the free surface is the Volume of Fluid (VOF) method. Along with using the VOF method …

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Thermal Maturity And Porosity Development During Catagensis In The Barnett Shale, Fort Worth Basin, Texas, Nathan Glondys Jan 2011

Thermal Maturity And Porosity Development During Catagensis In The Barnett Shale, Fort Worth Basin, Texas, Nathan Glondys

Earth & Environmental Sciences Theses - Archive

Unconventional resource plays are typified by significantly recoverable volumes of thermally mature hydrocarbons (oil, condensate and/or gases) trapped within a low permeability shale formation acting as source, reservoir and seal. These systems pose a scientific and engineering challenge to produce recoverable hydrocarbons from, chiefly due to their low permeabilities. There is growing evidence that secondary porosity in organic gas bearing shales is created during the thermal maturation of kerogen. A better understanding of porosity development during maturation of mobile organics during catagenesis may yield new insight on how we view these systems. A comparative analysis of the gas phase(s), peak …

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