Engineering Commons^™

Slow Complexity Wavelet Packet Compression Of Bayer Images For Communication Over Wireless Sensor Networks, Ivan Calzada

Open Access Theses & Dissertations

The purpose of this thesis was to develop a low complexity image compression algorithm for Wireless Sensor Networks (WSN). The main constraints in a WSN node are limited processing power, memory allocation, and battery life. The goal of this thesis was to develop an image compression algorithm that would thrive under this constraint environment. The main focus was to minimize the complexity of the algorithm by taking advantage of the spatial correlation found in Bayer images. The algorithm employs line based 1-D Discrete Wavelet Packets Transform of Bayer images. In addition the image compression method includes the application of a …

Simulation And Optimization Of Ultra Thin Photovoltaics, Jose Luis Cruz-Campa

Open Access Theses & Dissertations

Sandia National Laboratories (SNL) conducts pioneering research and development in Micro-Electro-Mechanical Systems (MEMS) and solar cell research. This dissertation project combines these two areas to create ultra-thin small-form-factor crystalline silicon (c-Si) solar cells. These miniature solar cells create a new class of photovoltaics with potentially novel applications and benefits such as dramatic reductions in cost, weight and material usage.

At the beginning of the project, unusually low efficiencies were obtained in the research group. The intention of this research was thus to investigate the main causes of the low efficiencies through simulation, design, fabrication, and characterization.

Commercial simulation tools were …

Quality Assesment In Bone Scaffolds Through Internet Based Robotic Using Intelligent Data Mining, Aditya Chilukuri

Open Access Theses & Dissertations

Optimization of design in fabricating scaffolds in an important step in obtaining tissue engineering scaffolds with appropriate shape and inner microstructure. Different shapes & sizes of scaffolds are modeled using UGS NX 6.0 modeling software with variable pore sizes. The quality issue we are concerned is about scaffold porosity, because of fabrication errors the porosity is not be very high for few models. There is lot of research ongoing for characterization using scanning electron microscope, but this study will introduce a new technique to characterize the scaffolds using network based robots, machine vision system and conveyor facility using which the …

Development Of A Micro-Catbed For Miniature Thrusters, Chance Paul Garcia

Open Access Theses & Dissertations

The goal of this work is to develop a micro catalytic bed for miniature thrusters. A test bed was constructed for experimental testing to characterize several parts of the micro catalytic bed. The reactant fluid studied is 90% Hydrogen Peroxide (H2O2) by weight. Three different cross sectional area designs were tested to determine decomposition efficiency, temperature reaction propensity, optimum flow rate, and temperature distribution across each bed. The products of decomposition were condensed to measure the oxygen released from decomposition. The results will be used to develop the basis for a micro catalytic bed design to implement into future miniature …

Titanium-Doped Tungsten Oxide For H2s Sensors: Synthesis, Microstructure And Property Evaluation, Narasimha Raju Kalidindi

Open Access Theses & Dissertations

Increasingly strict requirements for environment management of coal-generated waste streams are also anticipated with a growing incentive to reduce CO2 production through increased efficiency. This planning model imposes demanding requirements for conversion of coal to electricity and to clean gaseous and liquid fuels and, thus, for a strategic program of research, development and commercialization to most efficiently utilize coal resource in the 21st century. Two very important goals that are proposed with their longer time horizon are increasing emphasis on clean fuels research and on advanced research that addresses the barriers to higher efficiency in both power generation and fuels …

Computer-Aided Detection Of Sleep Apnea And Sleep Stage Classification Using Hrv And Eeg Signals, Edson F. Estrada

Open Access Theses & Dissertations

Sleep is a circadian rhythm essential for human life. Many events occur in the body during this state. In the past, significant efforts have been made to provide clinicians with reliable and less intrusive tools to automatically classify the sleep stages and detect apnea events. A few systems are available in the market to accomplish this task. However, sleep specialists may not have full confidence and trust in such systems due to issues related to their accuracy, sensitivity and specificity. The main objective of this work is to explore possible relationships among sleep stages and apneic events and improve on …

Decision Support Tools For Bus Rapid Transit Corridor Planning, Luis David Galicia

Open Access Theses & Dissertations

Bus Rapid Transit (BRT) Systems have been gained popularity in the United States and worldwide as a cost-effective solution of mass transit. There are certain elements and characteristics that such a system should accomplish to be considered a BRT. However, a uniform definition, defined phases to be deployed, and a reliable methodology to estimate ridership are not well structured and clear yet. The purpose of this research was to help BRT stakeholders with an effective method to plan and assess BRT projects. The first goal of this research was to provide a comprehensive description of the essential characteristics of BRT …

Microstructure And Property Evaluation Of Lifepo4 Thin Films For Application In Microbatteries, Jose Marcos Mares

Open Access Theses & Dissertations

The shortage of fossil fuels and the requirements to produce clean, environmental friendly, efficient, and economical energy are the principal problems in the context of energy technology for current and future generations. Therefore, advanced energy storage and conversion capabilities with higher capacity and efficiency are desired. Currently, there is an enormous interest in the development of high energy density rechargeable batteries for use in domestic applications, automotive industries and portable electronic applications. The present research focuses on the development of LiFePO4 thin films for solid-state thin-film microbatteries. The present effort was performed with a specific purpose of understanding the effect …

Design And Simulation Of A Position Sensitive Device With Gaussian Response, Debra Erin Medina

Open Access Theses & Dissertations

Not Required

Optimization Models For The Economic And Non-Economic Level Of Repair Analysis, Carlos Marco Ituarte-Villarreal

Open Access Theses & Dissertations

Every component, equipment or system will eventually fail. All failures produce a maintenance cost and, repair costs are especially hard to estimate ahead of time. Research shows that maintenance costs are the most substantial costs of development and use of equipment, reason why the cost of the product or equipment through its life is a major concern. Therefore, the main objective of this thesis is to provide a new optimization model to determine the minimum cost maintenance policy for complex systems.

Low Impact Development (Lid) Structures For Groundwater Management And Watershed Protection In The Amrc10 Watershed, El Paso Texas, Ricardo Sabino Marmolejo

Open Access Theses & Dissertations

The AMRC10 watershed was modeled in HEC-HMS and in Green Values. Theoretical storm water conveyance and capture models were tested in these programs along with several Low environmental Impact Development features to determine their applicability and performance at this site. Lots should all be designed with all roof downspouts draining into raingardens, at least half of all lawns should be natural landscaping using local vegetation, porous pavement should be used for all driveways, sidewalks and non-street pavement and drainage to the stormwater conveyance structures should make use of drainage swales instead of storm water pipes. To manage runoff three detention …

Compressive Sensing With Prior Information Applied To Magnetic Resonance Imaging, Cristiano Jacques Miosso

Open Access Theses & Dissertations

This dissertation introduces the theory of compressive sensing with prior information about a signal's sparse representation. We show, mathematically and in numerical simulations, that prior information improves signal reconstruction, in terms of number of required measurements, computation time and signal-to-noise ratios. Following, we present a set of methods for enhanced magnetic resonance imaging and tomography that can be combined with prior information, for enhanced image quality.

In developing the theory of compressive sensing with prior information, we provide a mathematical proof of the required condition (in terms of number of linear measurements) for reconstruction using the ideal approach of l0-minimization, …

Generation Of High Resolution Radar Signals Using Three Dimensional Chaotic Flows, Chandra Sekhar Pappu

Open Access Theses & Dissertations

The purpose of this project is to investigate the system parameter and certain signal processing techniques to achieve wide bandwidth and frequency agility in order to build a high resolution radar. The technique relies on the output of an n-dimensional (n>2) non-linear system that exhibits chaotic behavior.

Firstly, the compressed Lorenz attractor is considered which has a set of three state variables x, y and z and three control parameters &rho, &beta, and &sigma. By varying &rho and &beta as function of time highly chaotic parameter space region is simulated such that chaotic signal behaves optimally.

For comparison purpose …

A Gis-Based Emission And Air Quality Impact Assessment For Evaluating Transportation Mitigation Measures, Jose Maria Mares

Open Access Theses & Dissertations

The research presented here develops a framework that assesses a transportation project's air quality impact. The framework not only integrates transportation and emission modeling but also improves the accuracy of the emission estimates. In order to do this, the framework makes use of six modules: environmental conditions data input, GIS database, emission modeling, transportation network, post-processing, and graphical presentation. Each module aims to improve the quality and accuracy of the inputs used by MOBILE6.2. In addition, the framework has the capability, among other features, of presenting the emission estimates in a GIS-based modeling platform that enables the analyst to spatially …

Investigation Of Selective Nanohetero-Epitaxy Growth On Si(100) Substrates For Hgcdte Infrared Detector Applications, Aryzbe Diaz

Open Access Theses & Dissertations

The selective CdTe Nanohetero-Epitaxy growth on Si(100) substrates has been achieved without the use of a mask in an attempt to reduce the dislocation density at the CdTe/Si interface to 10⁵/cm³ using the Close-Space Sublimation (CSS) technique, which is a low-cost effective technique for the deposition of polycrystalline CdTe films. Furthermore, CdTe is a compound semiconductor with a direct bandgap of 1.5 eV, which makes it an ideal material for the applications of infrared detectors and solar cells. It has been demonstrated that the selective growth of CdTe on patterned Si(100) substrates results in CdTe grains with …

Applicability Of Mepdg For India Based On Texas Pavement And Environmental Conditions, Vamsi Krishna Pinnamaneni

Open Access Theses & Dissertations

The Indian pavement design guide uses empirical models which were adopted and modified from US design guides. As with any empirical model, the prediction capabilities are limited to the conditions for which it was developed. In USA, Mechanistic Empirical Pavement Design Guide (MEPDG) has been recently developed to account for increase in truck traffic and minimize premature failure of pavements. Since the new design uses mechanistic approach, it is expected that the design guide can better predict performance of pavements. In addition, mechanistic approach allows use of design guide for different pavement and environmental conditions by calibrating model parameters for …

Sensor Interpolation And Super Resolution Image Reconstruction Using The Optimal Recovery Framework, Veenarai Moram

Open Access Theses & Dissertations

Wireless sensor networks have the potential to benefit society in a myriad of ways, but due to constraints of sensor placement, obtaining the desired signals is not an easy problem. Retrieving the information accurately from sensors placed randomly is a challenging problem of sensor communication and signal interpolation. In this research the optimal recovery (OR) method, a deterministic framework that can use a priori bandwidth or spectral shape information, is used to interpolate from the given samples produced by sensors. In the reconstruction formulation, a worst case error signal occurs. To minimize this error, the OR method uses a norm …

Scrap Reduction Model: By Combination Of Dmaic And Design Of Experiments, Anoop J. Randive

Open Access Theses & Dissertations

This project deals with the experimentation which took place at a cable manufacturing company. The thesis describes and summarizes the various strategies and techniques that has been applied and practiced for scrap reduction. DMAIC and Six Sigma Technology has been proven very help full in order to reduce scrap to a major extent. DMAIC help to identify areas in process where extra expense exist, identify the biggest impact factor related production expenses, introduce appropriate measurement system, optimize process and reduce production cost and time. Many issues were detected by the production, such as a lack of a unified procedure for …

Effects Of Unbalanced Approach Volumes On Roundabout Operations, Marilyn Valdez

Open Access Theses & Dissertations

Modern roundabouts are increasingly popular in the United States due to their advantages in improving safety and reducing delay at intersections. A roundabout is an intersection in which traffic enters the intersection and travels in a circular counterclockwise motion around a center island. In a roundabout, priority is given to vehicles traveling in the circular roadway, and incoming traffic at the roundabout approach must yield to the circulating traffic. If there is an unbalance in approach volume, the approaches with higher input volumes may dominate the circulating flow preventing vehicles the other approaches to enter the roundabout. This may consequently …

12 Bit Charge Redistribution Digital To Analog Converter For The Residence Time Fluxgate Magnetometer, Miguel Angel Alamillo

Open Access Theses & Dissertations

The continuous advances in CMOS VLSI technology have culminated in high speed, low voltage CMOS digital circuits with gate delays below 50 ps at 1.5 V supply. At the same time, high voltage analog signal processing has fallen behind to the high flexibility and high reliability of DSP. However, the main drawback of DSP is the need for high accuracy low distortion data converters and as a consequence of the persistent efforts of reducing size, cost and power of solid-state components the field of CMOS Mixed-Signal circuit design has become of the utmost importance.

The obvious functionality of data converters …

Probabilistic Analysis Of Concrete Fracture, Mustafa Abushaala Aldalinsi

Open Access Theses & Dissertations

It is well known to civil engineers that fatigue leads to the bulk of structural failures. In plain and reinforced concrete structures, fatigue might account for excessive deformation, excessive of crack widths, de-bonding of reinforcement and rupture of the reinforcement, all of these can lead to structural collapse. Fatigue crack propagation can be a method to predict a remaining life of a structures. Herein will show some works that have been done in order to analyze the fatigue crack growth for plain concrete specimen. The goals of this study are to estimate the critical crack length and remaining life of …

Novel Control Technique For Cadmium Sulfide Chemical Bath Deposition Using Real Time Monitoring Of Cadmium Ion Molarity, Rafael Ordonez

Open Access Theses & Dissertations

Cadmium sulfide Chemical-Bath-Deposition parameters are modified to allow, for the first time, real time monitoring of cadmium ion molarity using a commercially available cadmium ion Ion-Selective-Electreode at 60°C. This modification involves alterations to typical deposition parameters that eliminate the formation of cadmium hydroxide and keep cadmium ion molarity above 10-7M. The new or atypical parameters developed are pH values below 8.9 and lower moralities for all chemicals. In order to have complexation of cadmium ion driven mainly by ammonia, parameters that minimized complexation by other chemicals are found. Cadmium acetate concentration below 2mM and ammonium acetate concentration below 10mM minimize …

A Variational Approach To Non-Newtonian Flow In Angular Pores: An Application To Enchanced Oil Recovery, Nithin Kavoori

Open Access Theses & Dissertations

With an alarming rise in carbon dioxide (CO2) emission from anthropogenic sources, CO2 sequestration has become an attractive choice to mitigate the emission. Some popular storage media for CO2 are oil reservoirs, deep coal-bed, deep oceanic-beds. These have been used for the long term CO2 storage. Due to special lowering viscosity and surface tension property of CO2, it has been widely used for enhanced oil recovery. The sites for CO2 sequestration or enhanced oil recovery mostly consist of porous rocks. In this thesis work, I focus on understanding the flow through porous at pore-level using variational approach.

Variational approach is …

Hybrid Manufacturing: Integrating Stereolithography And Direct Print Technologies, Amit Lopes

Open Access Theses & Dissertations

The focus of this research was the development of a hybrid manufacturing system that integrates stereolithography (SL) and direct print (DP) technologies to fabricate three dimensional (3D) structural electronic devices within a single set-up. The capabilities of this new additive manufacturing (AM) technology was explored in the context of fabricating and prototyping complex electronic devices in which conformal shape, rugged and light-weight integration, and a natural resistance to reverse engineering are all of paramount importance. Consequently, electronic components can be tightly integrated together in a rugged, light-weight 3D structure of arbitrary form. This research is a continuing advancement of the …

Renewable Energy Integration: An Approach For Micro-Grid Optimization., Nicolas Lopez

Open Access Theses & Dissertations

This thesis explores the Renewable Energy Integration Problem beginning with a literature review on the different sources of electrical energy classified as Non-Renewable and Renewable, stating that the integration of renewable sources within the pre-existing Power-Grids is a current worldwide problem that is being addressed with different approaches.

The impossibility to exactly model the different equations relating the electric output of the renewable energy sources as they relate with meteorological factors, makes the renewable sector a stochastic component of the overall mathematical model, where it can be concluded that most of the problem is in the area of the forecast. …

Computational Study Of Fluid-Valve Interaction Involving Deep Vein Thrombosis, Upendra Parimi

Open Access Theses & Dissertations

The venous valves in veins carry on the important function of eliminating the retrograde (re-verse) flow of blood in veins and help the veins to carry on their work effectively. The abnormal functioning of venous valves can cause deep vein thrombosis (DVT) which is a phenomena caused by clotting in deep veins. The importance of the thesis work lies in understanding the role of blood flow dynamics in Deep Vein Thrombosis (DVT). Elderly People and pregnant women are the ones who are most likely to develop DVT. It was determined from previous studies that women in their postpartum period are …

Optimal Sensor Placement In Environmental Research: Designing A Sensor Network Under Uncertainty, Aline James, Craig Tweedie, Tanja Magoc, Vladik Kreinovich, Martine Ceberio

Departmental Technical Reports (CS)

One of our main challenges in meteorology and environment research is that in many important remote areas, sensor coverage is sparse, leaving us with numerous blind spots. Placement and maintenance of sensors in these areas are expensive. It is therefore desirable to find out how, within a given budget, we can design a sensor network are important activities was developing reasonable techniques for sensor that would provide us with the largest amount of useful information while minimizing the size of the "blind spot" areas which is not covered by the sensors.

This problem is very difficult even to formulate in …

Symmetries: A General Approach To Integrated Uncertainty Management, Vladik Kreinovich, Hung T. Nguyen, Songsak Sriboonchitta

Departmental Technical Reports (CS)

We propose to use symmetries as a general approach to maintaining different types of uncertainty, and we show how the symmetry approach can help, especially in in economics-related applications.

Discrete Taylor Series As A Simple Way To Predict Properties Of Chemical Substances Like Benzenes And Cubanes, Jaime Nava, Vladik Kreinovich, Guillermo Restrepo, Douglas J. Klein

Departmental Technical Reports (CS)

In many applications, we have numerous molecules that are obtained from a "template" molecule like benzene C6H6 or cubane C8H8 by replacing some of its hydrogen atoms with other atoms or atom groups (called ligands). Depending on how many original atoms are replaced and which ones are replaced, we obtain a large number of different chemical substances. It is desirable to be able, based on the measurements performed on a small number of such substances, to accurately predict the characteristics (such as energy) of all similar substances.

Such predictions are very important, since, e.g. cubanes, while kinetically stable, are highly …

Towards Optimal Effort Distribution In Process Design Under Uncertainty, With Application To Education, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

In most application areas, we need to take care of several (reasonably independent) participants. For example, in controlling economics, we must make sure that all the economic regions prosper. In controlling environment, we want to guarantee that all the geographic regions have healthy environment. In education, we want to make sure that all the students learn all the needed knowledge and skills.

In real life, the amount of resources is limited, so we face the problem of "optimally" distributing these resources between different objects.

What is a reasonable way to formalize "optimally"? For each of the participants, preferences can be …