Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

University of Texas at Arlington

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 13261 - 13290 of 16090

Full-Text Articles in Entire DC Network

Towards A Stronger Peer-To-Peer Anonymous System, Arjun R. Nambiar May 2006

Towards A Stronger Peer-To-Peer Anonymous System, Arjun R. Nambiar

Computer Science and Engineering Theses - Archive

Anonymous communications systems on the Internet provides protection against eavesdroppers and others that seek to link users with their communications. These systems have many important applications in areas such as law enforcement, intelligence gathering, business privacy, anonymous publishing, and personal privacy. Currently deployed systems rely on a relatively small set of advertised servers to forward messages for the user. These systems can suffer from scalability problems, with potentially large bandwidth and system overhead costs, and the servers themselves can be targets of direct attacks. Peer-to-peer anonymous communications systems, such as Tarzan[1] and MorphMix [2], have been proposed as a way …

Go to article

Self-Organization And Resource Allocation In Wireless Sensor Networks, Liang Zhao May 2006

Self-Organization And Resource Allocation In Wireless Sensor Networks, Liang Zhao

Electrical Engineering Dissertations - Archive

In this dissertation, we utilize clustering to organize wireless sensors into an energy-efficient hierarchy. We propose a Medium-Contention Based ClusterHeadship Auction (MCCHA) scheme, through which sensors self-organize themselves into energy-efficient clusters by bidding for cluster headship. This scheme is based on a new criterion that can be used by each sensor node to make a distributed decision on whether electing to be a cluster head or a non-head member, which is a fully distributed approach. Although MCCHA uses only local information, it achieves better performance in terms of effective lifetime and Data/Energy Ratio compared with native LEACH, which relies on …

Go to article

Investigation Of Techniques To Increase The Scalability Of Graph-Based Data Mining Algorithms., Srilatha Inavolu May 2006

Investigation Of Techniques To Increase The Scalability Of Graph-Based Data Mining Algorithms., Srilatha Inavolu

Computer Science and Engineering Theses - Archive

Frequent subgraph pattern recognition and graph-based relational learning have been an emerging area of data mining research with scientific and commercial applications. At the kernel of these algorithms are the computationally-expensive graph and subgraph isomorphism tests. The graph isomorphism problem consists in deciding whether two graphs are isomorphic i.e., whether there is a one-one mapping between the vertices of the two graphs that respects the edge connections. Many graphs will be depicted quite differently but in actuality have the same inherent structure. This leads to the isomorphism problem. The graph isomorphism problem belongs to the class of NP problems and …

Go to article

Multiple Object Tracking Using Particle Filters, Hwangryol Ryu May 2006

Multiple Object Tracking Using Particle Filters, Hwangryol Ryu

Computer Science and Engineering Theses - Archive

We describe a novel extension to the Particle filter algorithm for tracking multiple objects. The recently proposed algorithms and the variants for multiple object tacking algorithms estimate multi-modal posterior distributions that potentially represent the multiple peaks (i.e., multiple tracked objects). However, the speci¯c state representation does not demonstrate birth, death and more importantly partial/complete occlusion of the objects. Furthermore, the weakness of the Particle Filter such that the representation may increasingly bias the posterior density estimates toward objects with dominant likelihood makes the multiple object tracking algorithms more di±cult. To circumvent a sample depletion problem and maintain the computational complexity …

Go to article

A Physics Based Multi-Resolution Technique For Extraction Of Finite Duration Time Responses In Radar Images, Nancy Lanett May 2006

A Physics Based Multi-Resolution Technique For Extraction Of Finite Duration Time Responses In Radar Images, Nancy Lanett

Electrical Engineering Theses - Archive

This paper presents a wavelet multi-resolution technique for examination of scattering phenomena in radar images. Through multi-resolution frequency domain analysis, range gating is implemented for extraction of wave medium interaction phenomena. To analyze the data, a sliding range gate is implemented by applying a phase shift to the spectral domain far field data prior to wavelet analysis. A method for efficient removal of window effects, which occur due to the finite nature of the data, is demonstrated through reconstruction of the decomposed waveform following removal of the lowest resolution. A correlation of the physical meaning of the multi-resolution data to …

Go to article

Design Of A Cmos Vco And Frequency Divider For 5 Ghz Applications, Prithvi Shylendra May 2006

Design Of A Cmos Vco And Frequency Divider For 5 Ghz Applications, Prithvi Shylendra

Electrical Engineering Theses - Archive

This thesis presents the design of a new CMOS Voltage Controlled Oscillator and a frequency divider, both of which form important blocks in the design of a PLL synthesizer. These components are important because they operate at the highest frequencies within the PLL and also consume most of the power as compared to the other components. Both these circuits have been an active topic of research in recent years especially with the scaling of technology bringing hopes of complete system-on-chip (SOC) integration at RF frequencies. The circuits in this thesis are designed for 5 GHz applications, mainly for the IEEE …

Go to article

Proximate And Ultimate Mechanisms Associated With Female Secondary Coloration In The Mexican Boulder Spiny Lizard, (Sceloporus Pyrocephalus), Rebecca Marie Calisi May 2006

Proximate And Ultimate Mechanisms Associated With Female Secondary Coloration In The Mexican Boulder Spiny Lizard, (Sceloporus Pyrocephalus), Rebecca Marie Calisi

Biology Theses - Archive

Secondary sexual coloration is thought to be the result of runaway selection for signals that honestly communicate relative fitness. Much theoretical work suggests sexual selection has driven conspicuous secondary traits in males while natural selection has driven inconspicuous traits in females; however, in some species, bright female secondary coloration does exist. I used the Mexican boulder spiny lizard (Sceloporus pyrocephalus) as a model to examine secondary coloration in females. Adult females of S. pyrocephalus have conspicuously colored gular regions, ranging from red, orange, to yellow, while adult males weakly express color in the gular region. Both sexes have dark stripes …

Go to article

Supervised Learning From Embedded Subgraphs, Joseph T. Potts May 2006

Supervised Learning From Embedded Subgraphs, Joseph T. Potts

Computer Science and Engineering Dissertations - Archive

We develop a machine learning algorithm which learns rules for classification from training examples in a graph representation. However, unlike most other such algorithms which use one graph for each example, ours allows all of the training examples to be in a single, connected graph. We employ the Minimum Description Length principle to produce a novel performance metric for judging the value of a learned classification. We implement the algorithm by extending the Subdue graph-based learning system. Finally, we demonstrate the use of the new system in two different domains, earth science and homeland security.

Go to article

Connections: Library News For Library Staff Vol. 3, Issue 4, University Of Texas At Arlington Library May 2006

Connections: Library News For Library Staff Vol. 3, Issue 4, University Of Texas At Arlington Library

Connections: Library News for Library Staff

The purpose of Connections was to build community within UTA Library staff by reminding people of upcoming events and dates, introducing new staff members, celebrating a department's achievements, and writing about other items of interest.

Go to article

Derivation Of Generalized Lorenz Systems To Study The Onset Of Chaos In High Dimension, Dipanjan Roy May 2006

Derivation Of Generalized Lorenz Systems To Study The Onset Of Chaos In High Dimension, Dipanjan Roy

Physics Theses - Archive

This thesis provides a new method to derive high dimensional generalized Lorenz systems. Lorenz system is a celebrated nonlinear dynamical dissipative system which was originally derived by Lorenz to study chaos in weather pattern. The classical two dimensional and dissipative Rayleigh-Benard convection can be approximated by Lorenz model, which was originally derived by taking into account only the lowest three Fourier modes. Numerous attempts have been made to generalize this 3D Lorenz model as the study of this high dimensional model will pave the way to better understand the onset of chaos in high dimensional systems of current interest in …

Go to article

Finite Element Analysis Of Moisture And Thermal Induced Stress In Flip Chip Packages, Santanu Ghosh May 2006

Finite Element Analysis Of Moisture And Thermal Induced Stress In Flip Chip Packages, Santanu Ghosh

Mechanical and Aerospace Engineering Theses - Archive

The process of moisture absorption and subsequent hygroswelling stress development is a cause of concern in the IC packaging industry. Also thermal stresses developed during the lead free reflow process with a high peak temperature (~ 250oC) add to the problem. In Flip Chip packages, the related effects are high shear stresses at the multilayer interfaces and normal stresses in solder balls. This can lead to phenomenon like delamination at the interfaces and UBM opening. In this work we have made an attempt to simulate the moisture absorption process, subsequent hygroswelling stress development, and thermal stress generated during reflow using …

Go to article

An Empirical Test Of The Situational Leadership® Model In Japan, Riho Yoshioka May 2006

An Empirical Test Of The Situational Leadership® Model In Japan, Riho Yoshioka

Public Affairs Theses - Archive

Since the collapse of the "bubble economy" in the early 1990s, Japanese companies have been struggling with financial difficulty, and have been forced to change their structure, strategies, and management systems. The trend of learning and importing successful American management theories and systems expanded to Japanese society. The Situational Leadership® model, developed by Hersey and Blanchard, is an example of this phenomenon. However, many cross-cultural studies propose that Japanese society has a different culture and values from American society. Therefore, by focusing on Situational Leadership®, this study examined whether models developed in the United States are suitable for Japanese companies. …

Go to article

Design And Development Of Embedded Dsp Controllers For Power Electronic Applications, Raman Nair Harish Gopala Pillai May 2006

Design And Development Of Embedded Dsp Controllers For Power Electronic Applications, Raman Nair Harish Gopala Pillai

Electrical Engineering Theses - Archive

Power applications like motor drives, inverters have complex algorithms that can be used to improve their efficiency. More often reduced manufacturing cost takes precedence over better efficiency. DSPs with their high computational power can provide reduced cost and higher efficiency. Though the cost of a standalone DSP chip has reduced, its integration to form a complete embedded product is an area often overlooked. High frequency of operation, reduced package size, and sensitivity to component placement are some of the factors that affect the interface between input/output devices and the DSP. This thesis presents the design and development of an embedded …

Go to article

Conditions For Wave Propagation Along Solar Magnetic Flux Tubes, Swati Routh May 2006

Conditions For Wave Propagation Along Solar Magnetic Flux Tubes, Swati Routh

Physics Theses - Archive

There is an intimate relation between all aspects of the solar activity and the presence of solar magnetic fields. Observations showed that the magnetic field at the photospheric level consists of magnetic flux tubes, which are located at supergranule boundaries. The flux tubes interact with the solar granulation and convection and, as a result, longitudinal, transverse and torsional magnetic tube waves are generated. These waves are responsible for carrying the energy to the upper parts of the solar atmosphere and heating the atmosphere to temperatures much higher than the solar photosphere. The energy carried by transverse and torsional waves may …

Go to article

Planning Cities For The Other Percent Of The Residents: Impacts On The Elderly And Disabled Community, Kellie D. Foster May 2006

Planning Cities For The Other Percent Of The Residents: Impacts On The Elderly And Disabled Community, Kellie D. Foster

Public Affairs Theses - Archive

The urban environment has evolved in the time since the Second World War. Advances in technology have been a catalyst for numerous urban problems; urban sprawl, poverty and a shortage of low to moderate-income housing, for example. When addressing these issues, city planners often neglect the needs of the disabled community. This is cause for concern because society is aging and due to advancements in medicine, the disabled population is growing exponentially. The focus of this thesis is the roll urban design and city planning has in the issues that plague the disabled community by examining both physical design and …

Go to article

Robust Airline Fleet Assignment, Venkata Pilla May 2006

Robust Airline Fleet Assignment, Venkata Pilla

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

The fleet assignment model allocates the fleet of aircraft types to the scheduled flight legs in the airline timetable published 90 days prior to the departure of the aircraft. The objective is to maximize profit. While costs associated with assigning a particular fleet type to a leg are easy to estimate, the revenues are based upon demand, which is realized close to departure. The uncertainty in demand makes it challenging to assign the right type of aircraft to each flight leg based on the forecasts taken 90 days prior to departure. Therefore, in this dissertation a two-stage stochastic programming framework …

Go to article

Registration Of Beta-Cit Dopamine Transporter Spect Images, Abhinay Dilip Joshi May 2006

Registration Of Beta-Cit Dopamine Transporter Spect Images, Abhinay Dilip Joshi

Bioengineering Theses - Archive

This work outlines a method for quantification of nigrostriatal dopaminergic neurons by means of SPECT using the cocaine derivative [123I] β-CIT (123I-labelled 2β-carbomethoxy-3β-(4-iodophenyl) tropane (β-CIT))as a radiotracer which binds with high affinity to the dopamine receptors. It has been validated (1) that the calculation of a simple ratio of specific/non-specific displaceable binding during a period of binding-equilibrium in the striatum about 20 hrs after the administration of a bolus injection of the tracer gives a strong and reliable index of the binding potential of dopamine uptake sites. Previous studies [2] have shown that the dopaminergic deficit in patients with Parkinson's …

Go to article

Phenotypic Differences In The Behavior Of Immortalized Human Bronchial Epithelial Cells In Three Dimensional Culture Systems, Anusha Sridharan May 2006

Phenotypic Differences In The Behavior Of Immortalized Human Bronchial Epithelial Cells In Three Dimensional Culture Systems, Anusha Sridharan

Bioengineering Theses - Archive

Human Bronchial Epithelial Cells (HBECS) immortalized with viral oncoproteins E6/E7, are potentially malignant due to numerous chromosomal aberrations. Recently a model system was established in which HBECS were immortalized with Cyclin-dependent-kinase-4 (Cdk4) and human Telomerase Reverse Transcriptase (hTERT). These cells were shown to have intact p53 checkpoints and had well expressed differentiation markers. HBECS are non-tumorigenic as they do not form tumors in nude mice or colonies in soft agar. The purpose of this research was to establish the differences in phenotypic behavior between HBECS immortalized with E6/E7 viral oncoproteins and HBECS immortalized with Cdk4/hTERT. A three dimensional culture model …

Go to article

Development Of A Multi-Channel Handheld Probe Designed For Near Infrared Spectroscopy And An Exploration Into Its Clinical Applications, Pradheep Raman May 2006

Development Of A Multi-Channel Handheld Probe Designed For Near Infrared Spectroscopy And An Exploration Into Its Clinical Applications, Pradheep Raman

Bioengineering Theses - Archive

Near Infrared (NIR) spectroscopy and imaging has become popular in research fields for the past 2 decades. My research focuses on the development of a handheld, multi-channel, multi-separation probe for the low-cost, compact, NIR spectroscopy (LCC-NIRS) system and also on the exploration into its possible clinical applications. The work is divided into three parts. The first part deals with the development of the multi-separation probe with source-detector separation of 3.8 cm, 3.3 cm, 3.0 cm, and 2.3 cm. The probe is designed to work as a tri-wavelength system for the LCC-NIRS, which was developed earlier, consisting of one light emitting …

Go to article

High Precision Spatial And Temporal Control Of Neural Circuitry Using Semi-Automated, Multiwavelength Nanopatterning System, Nagasandhya Mitnala May 2006

High Precision Spatial And Temporal Control Of Neural Circuitry Using Semi-Automated, Multiwavelength Nanopatterning System, Nagasandhya Mitnala

Bioengineering Theses - Archive

The ideal way to manipulate neurons would be to reversibly activate and inactivate neuronal firing and thus enable a bi-directional control. Many attempts have been made in the past to have such a tool. The traditional approach for controlling neural circuits is to generate a local electric field which has been shown to be highly effective at triggering action potentials in neurons [53]. Although the timing of the electrode stimulation is very precise, its specificity and spatial control are poor. Also, silencing neuronal activity is as important as stimulating it. Ed Boyden described a protein that switches off nerve firing …

Go to article

Optimization Of Methods For In-Vitro Expansion And Cryopreservation Of Mammalian Stem Cells, Harikrishnan Balachandran May 2006

Optimization Of Methods For In-Vitro Expansion And Cryopreservation Of Mammalian Stem Cells, Harikrishnan Balachandran

Bioengineering Theses - Archive

The recent advances in the field of Tissue Engineering have given rise to the need for a tremendous quantity of cells. The search for and use of an appropriate multipotent or pluripotent stem cells in tissue engineering is an emerging concept. Mesenchymal stem cells hold a very great deal of promise because of their capacity to self-renew and to differentiate into various lineages. These cells are very low in number in the body but their in vitro expansion capacity is very unique. Taking into consideration the lack of uniform approach for expansion of these MSCs and storing these cells for …

Go to article

Ut Arlington Library Notes, V.12, No.1, Spring 2006, University Of Texas At Arlington Library May 2006

Ut Arlington Library Notes, V.12, No.1, Spring 2006, University Of Texas At Arlington Library

UT Arlington Library Notes

Former publication of the UT Library intended to foster community support and appreciation for Library Programs and services and to spotlight grants and contributions. It was published during the 1990s and 2000s.

Go to article

Viscoplastic Finite-Element Simulation To Predict The Solder Joint Fatigue Life Of Different Flash Memory Die Stacking Architectures, Yong Je Lee Apr 2006

Viscoplastic Finite-Element Simulation To Predict The Solder Joint Fatigue Life Of Different Flash Memory Die Stacking Architectures, Yong Je Lee

Mechanical and Aerospace Engineering Theses - Archive

This thesis focuses on the viscoplastic finite-element simulation to predict the solder joint fatigue life of different die stacking architectures for flash memory products. Four different stacked package architectures were evaluated as follows: pyramid, rotated, and spacer stacking, while interconnection (solder joint) was held constant. Number of dies for all four stacking configurations were varied from three, five and seven. To keep the package height constant, the die and die attach thickness were varied and the resulting effects on the stresses were investigated. A quarter and half symmetry model of stacked flash package are generated using ANSYS APDL script. The …

Go to article

The Booster Network: A Framework For Analyzing State Policy Formation In An Era Of Resurgent Private Power, Patrick Embry Apr 2006

The Booster Network: A Framework For Analyzing State Policy Formation In An Era Of Resurgent Private Power, Patrick Embry

Public Affairs Theses - Archive

The continuing shift toward privatization has created new opportunities for private participation in transportation policy formation, infrastructure development, and service provision. The resulting high stakes have drawn a variety of traditionally powerful private players to overtly participate in Texas state policy making. Understanding policy formation in this era of resurgent private power is imperative because the outcomes will affect urban development, population distribution, and subsequent politics and policy. With this paper, I analyze Trans Texas Corridor policy formation using a new framework, the booster network. The framework is based in policy studies and urban development literatures, conceptualizes policy formation in …

Go to article

Statistical Analysis Of Compressive Strength Of Clay Brick Masonry Prisms, Saman Afqahi Aryana Apr 2006

Statistical Analysis Of Compressive Strength Of Clay Brick Masonry Prisms, Saman Afqahi Aryana

Civil Engineering Theses - Archive

The Specification for Masonry Structures section of the current governing masonry design document in the U.S., reported by the Masonry Standards Joint Committee (MSJC), contains tables that can be used to determine the compressive strength of masonry, f'm, as a function of the mortar type and the compressive strength of the unit employed to construct the masonry. The majority of the data gathered to create the current values in the MSJC Specification were generated in studies done prior to 1970. There have been significant changes in materials and procedures since this time frame, and there is a need to gather …

Go to article

Power And Distortion Optimized Video Coding For Pervasive Computing Applications, Yongfang Liang Apr 2006

Power And Distortion Optimized Video Coding For Pervasive Computing Applications, Yongfang Liang

Computer Science and Engineering Dissertations - Archive

This dissertation investigates video encoding schemes for pervasive computing applications that must ensure low power consumption in addition to high compression efficiency. The contribution of the dissertation is the formulation of a theoretical problem that captures the joint optimization of power and distortion in video coding. The study of the complexity distribution of typical video encoders helps to develop a complexity-scalable video encoding architecture that includes several control parameters to adjust the power consumption of the major modules of the encoder. An analytic framework to model, control and optimize the power-rate-distortion is developed, which facilitates the development of optimization schemes …

Go to article

Comparison Of The Ingestion And Digestion Rates Of Ochromonas Danica Grazing On Pseudomonas Fluorescens Of Varying Food Quality, Stephen Paul Shannon Apr 2006

Comparison Of The Ingestion And Digestion Rates Of Ochromonas Danica Grazing On Pseudomonas Fluorescens Of Varying Food Quality, Stephen Paul Shannon

Biology Dissertations - Archive

Flagellate prey selection appears to depend on morphological characteristics of prey such as cell size and motility, as well as on physiochemical characteristics such as digestibility and cell surface characteristics. Pseudomonas fluorescens was grown in chemostats at four dilution rates (0.03, 0.06, 0.10, 0.13 h-1) and three temperatures (14, 20, 28°C) to produce cells of varying morphological characteristics (cell size) and physiochemical characteristics or food quality (as determined by the C:N:P ratio). Heat-killed bacteria of a given food quality were prepared and used to grow the flagellate Ochromonas danica. Ingestion and digestion rates were determined using fluorescently labeled bacteria of …

Go to article

New Developments Of The Deformation Method, Jie Liu Apr 2006

New Developments Of The Deformation Method, Jie Liu

Mathematics Dissertations - Archive

New developments of deformation method for grid generation are presented in this work. Theorems for three different cases and different methods for implementing deformation method are presented. One of the new developments is a 3D multi-block moving grid method. In this version, a Poisson equation is solved by finite difference method to get the vector field for moving grid. Special treatment applies to the common boundary of different blocks. Another new development is a numerical method for reconstructing a given differentiable transformations by solving a system of div-curl equation directly formed from each point of the graph. The determinacy and …

Go to article

Information Processing In A Structured Interview: Identifying Use Of Heuristics And Heuristic-Based Bias, Dian Cuellar Ruud Apr 2006

Information Processing In A Structured Interview: Identifying Use Of Heuristics And Heuristic-Based Bias, Dian Cuellar Ruud

Social Work Dissertations - Archive

The survey interview has been recognized as the most frequently used data collection procedure in the social sciences (Dijkstra & van der Zouwen, l987). Although the survey interview is an essential methodological tool in social science research, it is fraught with problems of validity and reliability. Cognitive psychology offers a perspective to further explore the methodological facets of the survey interview. Research in the underlying cognitive processes involved in information processing over the past two decades has enhanced the understanding and utility of the survey interview in survey methodology (Tourangeau, Couper, & Conrad, 2004; Tourangeau, Rips, & Rasinski, 2000; Sudman, …

Go to article

A Qualitative Examination Of Risk Factors Influencing Female Adolescent Delinquency In Dallas County, Texas, Vicki Lynn Tankersley Apr 2006

A Qualitative Examination Of Risk Factors Influencing Female Adolescent Delinquency In Dallas County, Texas, Vicki Lynn Tankersley

Social Work Dissertations - Archive

The purpose of this study was to identify the risk factors influencing juvenile delinquency for females in Dallas County, Texas and discuss the implications of the findings for future practice, policy, and research. Qualitative research methods in this study have given a voice to female adolescents housed in the Dallas County Juvenile Detention Center by giving these young women the opportunity to share and convey information about their lives and factors they felt had been influential in their referral to the Dallas County Juvenile Probation Department. The sample included twenty-six female adolescents who were housed at the Dallas County Juvenile …

Go to article

First Prev Next Last