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2012

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Articles 91 - 120 of 8503

Full-Text Articles in Physical Sciences and Mathematics

Quantification Of Carbon Emission Reduction By U-Transportation Service Effect: A Case Study Of Dongtan U-City, Tae-Woong Jung, Mu-Wook Pyeon, Jee-Hee Koo Dec 2012

Quantification Of Carbon Emission Reduction By U-Transportation Service Effect: A Case Study Of Dongtan U-City, Tae-Woong Jung, Mu-Wook Pyeon, Jee-Hee Koo

Journal of Marine Science and Technology–Taiwan

With the emergence of the response to climate change as a global agenda, UNFCCC member countries must report their Greenhouse Gas (GHG) emissions and absorptions. With conventional carbon emission estimation methods such as the IPCC Guideline, however, it is impossible to measure reduction of carbon emissions by U-City services. Therefore, this study proposed estimating carbon emission reductions by using U-transportation services as a model because this service appears to be the most effective among U-City services in terms of carbon emission reduction. This approach which is unique in Korea has also attempted to quantify the reduction of carbon emissions by …


Connotational Subtyping And Runtime Class Mutability In Ruby, Ian S. Dillon Dec 2012

Connotational Subtyping And Runtime Class Mutability In Ruby, Ian S. Dillon

Electronic Theses and Dissertations

Connotational subtyping is an approach to typing that allows an object's type to change dynamically, following changes to the object's internal state. This allows for a more precise representation of a problem domain with logical objects that have variable behavior. Two approaches to supporting connotational subtyping in the Ruby programming language were implemented: a language-level implementation using pure Ruby and a modification to the Ruby 1.8.7 interpreter. While neither implementation was wholly successful the language level implementation created complications with reflective language features like self and super and, while Ruby 1.8.7 has been obsoleted by Ruby 1.9 (YARV), the results …


Cost Effective Domination In Graphs, Tabitha Lynn Mccoy Dec 2012

Cost Effective Domination In Graphs, Tabitha Lynn Mccoy

Electronic Theses and Dissertations

A set S of vertices in a graph G = (V,E) is a dominating set if every vertex in V \ S is adjacent to at least one vertex in S. A vertex v in a dominating set S is said to be it cost effective if it is adjacent to at least as many vertices in V \ S as it is in S. A dominating set S is cost effective if every vertex in S is cost effective. The minimum cardinality of a cost effective dominating set of G is the cost …


Interferometric Synthetic Aperture Sonar Signal Processing For Autonomous Underwater Vehicles Operating Shallow Water, Patricia E. Giardina Dec 2012

Interferometric Synthetic Aperture Sonar Signal Processing For Autonomous Underwater Vehicles Operating Shallow Water, Patricia E. Giardina

LSU New Orleans Theses and Dissertations

The goal of the research was to develop best practices for image signal processing method for InSAS systems for bathymetric height determination. Improvements over existing techniques comes from the fusion of Chirp-Scaling a phase preserving beamforming techniques to form a SAS image, an interferometric Vernier method to unwrap the phase; and confirming the direction of arrival with the MUltiple SIgnal Channel (MUSIC) estimation technique. The fusion of Chirp-Scaling, Vernier, and MUSIC lead to the stability in the bathymetric height measurement, and improvements in resolution. This method is computationally faster, and used less memory then existing techniques.


Blow-Up Of Solutions To The Generalized Inviscid Proudman-Johnson Equation, Alejandro Sarria Dec 2012

Blow-Up Of Solutions To The Generalized Inviscid Proudman-Johnson Equation, Alejandro Sarria

LSU New Orleans Theses and Dissertations

The generalized inviscid Proudman-Johnson equation serves as a model for n-dimensional incompressible Euler flow, gas dynamics, high-frequency waves in shallow waters, and orientation of waves in a massive director field of a nematic liquid crystal. Furthermore, the equation also serves as a tool for studying the role that the natural fluid processes of convection and stretching play in the formation of spontaneous singularities, or of their absence.

In this work, we study blow-up, and blow-up properties, in solutions to the generalized, inviscid Proudman-Johnson equation endowed with periodic or Dirichlet boundary conditions. More particularly,regularity of solutions in an Lp setting will …


Application Of Digital Forensic Science To Electronic Discovery In Civil Litigation, Brian Roux Dec 2012

Application Of Digital Forensic Science To Electronic Discovery In Civil Litigation, Brian Roux

LSU New Orleans Theses and Dissertations

Following changes to the Federal Rules of Civil Procedure in 2006 dealing with the role of Electronically Stored Information, digital forensics is becoming necessary to the discovery process in civil litigation. The development of case law interpreting the rule changes since their enactment defines how digital forensics can be applied to the discovery process, the scope of discovery, and the duties imposed on parties. Herein, pertinent cases are examined to determine what trends exist and how they effect the field. These observations buttress case studies involving discovery failures in large corporate contexts along with insights on the technical reasons those …


Geochemical Evidence For Vertical Migration Of Deep Formation Fluids Through The Baton Rouge -Denham Springs Fault System, Lesley C. Prochaska Dec 2012

Geochemical Evidence For Vertical Migration Of Deep Formation Fluids Through The Baton Rouge -Denham Springs Fault System, Lesley C. Prochaska

LSU New Orleans Theses and Dissertations

Accumulations of brackish groundwater exist across south Louisiana within the shallow, south-dipping Pleistocene to Upper Miocene Baton Rouge Aquifer System (BRAS). This research investigates the source of brackish groundwater through geochemical analysis of representative groundwater samples by comparing the following geochemical ratios along with other trace elements. Low Bromide (Br)/Chloride (Cl) and Potassium (K) /Cl ratios, high Sodium (Na) /Cl ratios, trace Magnesium (Mg) concentrations, and low Strontium (Sr) 87/Sr86 in brackish waters from the BRAS are inconsistent with in situ saline water from marine formation fluids of similar age. The ratios are consistent with in situ saline-water …


Calculation Of A Synthetic Gather Using The Aki-Richards Approximation To The Zoeppritz Equations, Graham Ganssle Dec 2012

Calculation Of A Synthetic Gather Using The Aki-Richards Approximation To The Zoeppritz Equations, Graham Ganssle

LSU New Orleans Theses and Dissertations

A synthetic seismic gather showing amplitude versus offset can be analyzed by the interpretive geophysicist to predict rock properties useful in oil exploration. Reflection coefficients derived from measured well log data are convolved with a Ricker wavelet to create a synthetic seismic trace. The Zoeppritz equations describe the propagation of an acoustic wave across an interface between two viscous media of different acoustic impedances with respect to increasing offset angle. The Aki-Richards linear approximation is used to create a synthetic seismic gather with offset angles up to fifty degrees. This gather is compared to a synthetic gather created using commercially …


Geomorphologic Evolution Of A Rapidly Deteriorating Barrier Island System With Multiple Sediment Sources: Eastern Isles Dernieres, Louisiana, 1887 To 2006, Benjamin T. Kirkland Dec 2012

Geomorphologic Evolution Of A Rapidly Deteriorating Barrier Island System With Multiple Sediment Sources: Eastern Isles Dernieres, Louisiana, 1887 To 2006, Benjamin T. Kirkland

LSU New Orleans Theses and Dissertations

Trinity, East, and Wine Islands make up the eastern half of the Isles Dernieres barrier arc in south-central Louisiana. Formed following the abandonment of the Lafourche delta complex, subsidence and storm erosion have led to rapid deterioration of the system. Since 1887, the land area of the islands has decreased seventy-seven percent, and the gulf shoreline has retreated landward more than a kilometer. Wave ravinement on the shoreface of the islands is responsible for the most sediment loss; liberated sediment travels longshore to tidal inlets. The dominant ebb tidal currents then transport the sediment to where it is deposited in …


Application Of Web Mashup Technology To Oyster Information Services, Christian Chuindja Ngniah Dec 2012

Application Of Web Mashup Technology To Oyster Information Services, Christian Chuindja Ngniah

LSU New Orleans Theses and Dissertations

Web mashup is a lightweight technology used to integrate data from remote sources without direct access to their databases. As a data consumer, a Web mashup application creates new contents by retrieving data through the Web application programming interface (API) provided by the external sources. As a data provider, the service program publishes its Web API and implements the specified functions.

In the project reported by this thesis, we have implemented two Web mashup applications to enhance the Web site oystersentinel.org: the Perkinsus marinus model and the Oil Spill model. Each model overlay geospatial data from a local database …


Water-Soluble Deep-Cavity Cavitands: Synthesis, Molecular Recognition, And Interactions With Phospholipid Membranes, Sarah E. Ioup Dec 2012

Water-Soluble Deep-Cavity Cavitands: Synthesis, Molecular Recognition, And Interactions With Phospholipid Membranes, Sarah E. Ioup

LSU New Orleans Theses and Dissertations

Water-soluble deep-cavity cavitands provide a rare opportunity to study self-assembly driven by the hydrophobic effect. These molecular hosts dimerize in the presence of certain guest molecules to form water-soluble molecular capsules. These systems have given rise to numerous novel chemical phenomena and have potential use in drug delivery. The host octaacid (OA) has been particularly well-characterized, but studies are limited to basic pH because of limited host solubility.

Herein we report an improved synthesis of OA and the syntheses of three new water-soluble deep-cavity cavitands. The new hosts are soluble at neutral pH, increasing relevance for biological studies. The new …


Open Source Remote Sensing:Introspect And Prospect, Sanggoo Kang, Hee Young Yoo, Kiwon Lee Dec 2012

Open Source Remote Sensing:Introspect And Prospect, Sanggoo Kang, Hee Young Yoo, Kiwon Lee

Journal of Marine Science and Technology–Taiwan

It is noteworthy that open source applications have been developed and studied in various fields as well as remote sensing field. Open sources for GIS have long history related to open standards over three decades, but those of remote sensing do relatively short. Moreover, there are still no summary reports for open sources for remote sensing. In this study, we summarized characteristics of open source applications for remotely sensed image processing and discussed their strengths and weaknesses at first. Based on the summary, two open source applications for InSAR Processing and Geographic Object-Based Image Analysis are practically implemented to introspect …


Assessment Of Disaster Losses In Rice Paddy Field And Yield After Tsunami Induced By The 2011 Great East Japan Earthquake, Yuei-An Liou, Hsueh-Chun Sha, Ting-Ming Chen, Tai-Sheng Wang, Yi-Ting Li, Yen-Cheng Lai, Min-Hsin Chiang, Li-The Lu Dec 2012

Assessment Of Disaster Losses In Rice Paddy Field And Yield After Tsunami Induced By The 2011 Great East Japan Earthquake, Yuei-An Liou, Hsueh-Chun Sha, Ting-Ming Chen, Tai-Sheng Wang, Yi-Ting Li, Yen-Cheng Lai, Min-Hsin Chiang, Li-The Lu

Journal of Marine Science and Technology–Taiwan

The Great East Japan Earthquake on 11 March 2011 triggered an extremely destructive tsunami that hit the Tohoku region of Japan severely. According to data from the Ministry of Agriculture, Forestry, and Fishes of Japan, Tohoku accounted for 27.59% of Japan’s rice yield in 2010. It is an impact to a country that relies on rice as its main food source. This paper utilizes remote sensing techniques to estimate the disaster losses in rice field and yield in Fukushima and Miyagi, the most severely damaged coastal prefectures of the Tohoku region, by using a developed Rice field Identification and riCe …


An Object-Oriented Analysis For Characterizing The Rainfall-Induced Shallow Landslide, Kuan-Tsung Chang, Jin-King Liu, Chu-I Wang Dec 2012

An Object-Oriented Analysis For Characterizing The Rainfall-Induced Shallow Landslide, Kuan-Tsung Chang, Jin-King Liu, Chu-I Wang

Journal of Marine Science and Technology–Taiwan

Landslides are natural phenomena for the dynamic balance of the earth's surface. Because of frequent occurrences of typhoons and earthquakes in Taiwan, mass movements are common threats to people's lives. In this paper, the interpretation of knowledge is quantified as recognition criteria. Multisource high-resolution data, for example, a SPOT satellite image, 20 m × 20 m Digital Terrain Model (DTM) reduced from Light Detection And Ranging (LiDAR) data, and aerial orthophotos were used to construct the feature space for landslide analysis. Landslides were recognized by an objectoriented method combining edge-based segmentation and a Supported Vector Machine (SVM) method. The classification …


Data Integration: A Case Study In The Financial Services Industry, Louis Epie Dec 2012

Data Integration: A Case Study In The Financial Services Industry, Louis Epie

Regis University Student Publications (comprehensive collection)

Current economic conditions result in banks participating in multiple mergers and acquisitions. This results in banks inheriting silo and heterogeneous systems. For banks to remain competitive, they must create a strategy to integrate data from these acquired systems in a dynamic, efficient, and consumable manner. This research considers a case study of a large financial services company that has successfully integrated data from different sources. In addition this research investigates endeavors that experts in the field have undertaken to develop architectures that address the problems with data integration and appropriate solutions.


Depth-Variable Settlement Patterns And Predation Influence On Newly Settled Reef Fishes (Haemulon Spp., Haemulidae), Lance K. B. Jordan, Kenyon C. Lindeman, Richard E. Spieler Dec 2012

Depth-Variable Settlement Patterns And Predation Influence On Newly Settled Reef Fishes (Haemulon Spp., Haemulidae), Lance K. B. Jordan, Kenyon C. Lindeman, Richard E. Spieler

Marine & Environmental Sciences Faculty Articles

During early demersal ontogeny, many marine fishes display complex habitat-use patterns. Grunts of the speciose genus Haemulon are among the most abundant fishes on western North Atlantic coral reefs, with most species settling to shallow habitats (≤12 m). To gain understanding into cross-shelf distributional patterns exhibited by newly settled stages of grunts (<2 cm total length), we examined: 1) depth-specific distributions of congeners at settlement among sites at 8 m, 12 m, and 21 m, and 2) depth-variable predation pressure on newly settled individuals (species pooled). Of the six species identified from collections of newly settled specimens (n = 2125), Haemulon aurolineatum (tomtate), H. flavolineatum(French grunt), and H. striatum (striped grunt) comprised 98% of the total abundance; with the first two species present at all sites. Prevalence of H. aurolineatum and H. flavolineatumdecreased substantially from the 8-m site to the two deeper sites. In contrast, …


Epr And Endor Studies Of Point Defects In Lithium Tetraborate Crystals, Douglas A. Buchanan Dec 2012

Epr And Endor Studies Of Point Defects In Lithium Tetraborate Crystals, Douglas A. Buchanan

Theses and Dissertations

Lithium tetraborate (Li2B4O7 or LTB) is a promising material for both radiation dosimetry and neutron detection applications. LTB crystals can be grown pure or doped with different impurities including transition-metal and rare-earth ions. Research in this dissertation focuses on undoped LTB crystals and LTB crystals doped with copper and silver. Electron paramagnetic resonance (EPR) and electron-nuclear double resonance (ENDOR) are used to characterize point defects in the lithium tetraborate crystals. Thermoluminescence (TL), photoluminescence (PL), photoluminescence excitation (PLE), and optical absorption (OA) are also used. An intrinsic hole trap associated with lithium vacancies is characterized with EPR and ENDOR and its …


Evaluation Of The Survival Effect For Various Treatment Modalities Among Stage Ii And Iii Rectal Cancer Patients In California, 1994-2009, Myung Mi Cho Dec 2012

Evaluation Of The Survival Effect For Various Treatment Modalities Among Stage Ii And Iii Rectal Cancer Patients In California, 1994-2009, Myung Mi Cho

Loma Linda University Electronic Theses, Dissertations & Projects

Background: European trials evaluating the effect of preoperative (PreOP) versus postoperative chemoradiotherapy (PostOP CRT) found no survival benefit. However, the effect of a change from PostOP to PreOP CRT has not been evaluated in a population-based setting. We sought to evaluate multimodal treatment changes and overall survival for perioperative (PeriOP) CRT versus surgery alone and for PreOP versus PostOP CRT from 1994 through 2009 among patients receiving radical surgery for stage II and III rectal cancer (RC).

Patients and Methods: We conducted a nonconcurrent cohort study evaluating demographic predictors of multimodal therapy for stage II and III RC using …


Stream-Associated Amphibian Habitat Assessment In The Portland-Vancouver Metropolitan Region, Andrew Evans Dietrich Dec 2012

Stream-Associated Amphibian Habitat Assessment In The Portland-Vancouver Metropolitan Region, Andrew Evans Dietrich

Dissertations and Theses

This study assessed the influence of landscape development on stream-associated amphibians in forested riparian areas within the Portland-Vancouver metropolitan region. Human alteration of landscapes may dramatically affect the ecology of neighboring aquatic systems. It was hypothesized that lotic amphibians would be negatively associated with greater amounts of landscape development and positively associated with forested area within the surrounding watershed. Thirty-seven 1st-3rd order streams were sampled between June 21st and September 21st in 2011. Streams potentially providing adequate habitat for stream-obligate amphibians were randomly selected. Amphibians were surveyed along 30-meter stream transects using an active-cover search (ACS). Environmental variables associated with …


Breaking Weak 1024-Bit Rsa Keys Using Cuda, Kerry Scharfglass, Darrin Weng, Joseph White, Christopher Lupo Dec 2012

Breaking Weak 1024-Bit Rsa Keys Using Cuda, Kerry Scharfglass, Darrin Weng, Joseph White, Christopher Lupo

Computer Science and Software Engineering

An exploit involving the greatest common divisor (GCD) of RSA moduli was recently discovered [1]. This paper presents a tool that can efficiently and completely compare a large number of 1024-bit RSA public keys, and identify any keys that are susceptible to this weakness. NVIDIA's graphics processing units (GPU) and the CUDA massively-parallel programming model are powerful tools that can be used to accelerate this tool. Our method using CUDA has a measured performance speedup of 27.5 compared to a sequential CPU implementation, making it a more practical method to compare large sets of keys. A computation for finding GCDs …


Secure Hierarchical Data Aggregation In Wireless Sensor Networks: Performance Evaluation And Analysis, Vimal Kumar, Sanjay Kumar Madria Dec 2012

Secure Hierarchical Data Aggregation In Wireless Sensor Networks: Performance Evaluation And Analysis, Vimal Kumar, Sanjay Kumar Madria

Computer Science Faculty Research & Creative Works

Secure data aggregation in wireless sensor networks has two contrasting objectives, i) Efficiently collecting and aggregating data and ii) Aggregating the data securely. Many schemes do not take into account the possibility of corrupt aggregators and allow the aggregator to decrypt data in hop-by-hop algorithms. on the other hand, using public key cryptography for providing end to end security is not energy efficient. in this paper we present and analyze the performance of the secure hierarchical data aggregation algorithm which uses an efficient public key cryptosystem (elliptic curve cryptography) to achieve end to end security. Unlike many other secure data …


Trust Management Of Encrypted Data Aggregation In A Sensor Network Environment, Nayot Poolsappasit, Michael Busby, Sanjay Kumar Madria Dec 2012

Trust Management Of Encrypted Data Aggregation In A Sensor Network Environment, Nayot Poolsappasit, Michael Busby, Sanjay Kumar Madria

Computer Science Faculty Research & Creative Works

Efficient power management is vital for increasing the life of sensor nodes in wireless sensor networks (WSN). Thus, techniques such as data aggregation have been widely used in WSN to preserve nodes' energy. Despite its appealing and powerful features, data aggregation processes require a high level of security. Ensuring accuracy with aggregating data can become an issue even due to single bit errors. Hence, many encryption techniques have been proposed to secure the data aggregation process. However, once a wireless sensor is physically compromised, the keys stored on the sensor are exposed, thus rendering the cryptography useless. Moreover, most cryptographic …


Crowdsourcing: Dynamic Data Management In Mobile P2p Networks, Sanjay Kumar Madria, Anirban Mondal Dec 2012

Crowdsourcing: Dynamic Data Management In Mobile P2p Networks, Sanjay Kumar Madria, Anirban Mondal

Computer Science Faculty Research & Creative Works

No abstract provided.


Interactions Of Aqueous Ag+ With Fulvic Acids: Mechanisms Of Silver Nanoparticle Formation And Investigation Of Stability, Nathaniel F. Adegboyega, Virender K. Sharma, Karolina Siskova, Radek Zboril, Mary Sohn, Brian J. Schultz, Sarbajit Banerjee Dec 2012

Interactions Of Aqueous Ag+ With Fulvic Acids: Mechanisms Of Silver Nanoparticle Formation And Investigation Of Stability, Nathaniel F. Adegboyega, Virender K. Sharma, Karolina Siskova, Radek Zboril, Mary Sohn, Brian J. Schultz, Sarbajit Banerjee

Chemistry and Chemical Engineering Faculty Publications

This study investigated the possible natural formation of silver nanoparticles (AgNPs) in Ag+ −fulvic acid (FA) solutions under various environmentally relevant conditions (temperature, pH, and UV light). Increase in temperature (24−90 °C) and pH (6.1−9.0) of Ag+ −Suwannee River fulvic acid (SRFA) solutions accelerated the appearance of the characteristic surface plasmon resonance (SPR) of AgNPs. The rate of AgNP formation via reduction of Ag+ in the presence of different FAs (SRFA, Pahokee Peat fulvic acid, PPFA, Nordic lake fulvic acid, NLFA) and Suwannee River humic acid (SRHA) followed the order NLFA > SRHA > PPFA > SRFA. This order was found to be …


Maximizing The Hyperpolarizability Poorly Determines The Potential, J. Lesnefsky, Greg A. Wiggers, Rolfe G. Petschek Dec 2012

Maximizing The Hyperpolarizability Poorly Determines The Potential, J. Lesnefsky, Greg A. Wiggers, Rolfe G. Petschek

Faculty Scholarship

The dimensionless zero-frequency electronic first hyperpolarizability 3−1/4βE7/210m3/2(eℏ)−3 of an electron in one dimension was maximized by adjusting the shape of a piecewise linear potential. Careful maximizations converged quickly to 0.708951 with increasing numbers of parameters. The Hessian shows that β is strongly sensitive to only two parameters in the potential: sensitivity to additional parameters decreases rapidly. With more than two parameters, a wide range of potentials and an apparently narrower range of wavefunctions have nearly optimal hyperpolarizability. Modulations of the potential to which the unique maximum is insensitive were characterized. Prospects for concise description of the two important constraints on …


Assessing The Human Impact Deer Frequency And Activity In The Depauw University Nature Park, Amanda Faulkenberg Dec 2012

Assessing The Human Impact Deer Frequency And Activity In The Depauw University Nature Park, Amanda Faulkenberg

Student Research

Introduction
White-tailed deer are abundant in the DePauw Nature Park. There are many deer trails located in forested areas in the park. The goal of our research was to assess the relationship between the amount of deer trails and the abundance of deer.

Hypotheses
We hypothesized that more deer would be photographed by cameras located in areas with the most deer trails.

Methods
We conducted our research in two forested areas, Quarry Hillside and Quarry South, in the DePauw Nature Park. We randomly selected five plots in each area. We mapped each deer trail and measured the length, width, and …


Parametrizing Finite Frames And Optimal Frame Completions, Miriam J. Poteet Dec 2012

Parametrizing Finite Frames And Optimal Frame Completions, Miriam J. Poteet

Theses and Dissertations

Frames are used in many signal processing applications. We consider the problem of constructing every frame whose frame operator has a given spectrum and whose vectors have prescribed lengths. For a given spectrum and set of lengths, we know when such a frame exists by the Schur-Horn Theorem; it exists if and only if its spectrum majorizes its squared lengths. We provide a more constructive proof of Horn's original result. This proof is based on a new method for constructing any and all frames whose frame operator has a prescribed spectrum and whose vectors have prescribed lengths. Constructing all such …


Seasonal Dimorphism In The Horny Bills Of Sparrows, Russell Greenberg, Matthew Etterson, Raymond M. Danner Dec 2012

Seasonal Dimorphism In The Horny Bills Of Sparrows, Russell Greenberg, Matthew Etterson, Raymond M. Danner

United States Environmental Protection Agency: Publications

Bill size is often viewed as a species-specific adaptation for feeding, but it sometimes varies between sexes, suggesting that sexual selection or intersexual competition may also be important. Hypotheses to explain sexual dimorphism in avian bill size include divergence in feeding niche or thermoregulatory demands, intrasexual selection based on increased competition among males, or female preference. Birds also show seasonal changes in bill size due to shifts in the balance between growth rate and wear, which may be due to diet or endogenous rhythms in growth. Insight into the function of dimorphism can be gained using the novel approach of …


Hybrid Solvers For The Boolean Satisfiability Problem: An Exploration, Nicole Nelson Dec 2012

Hybrid Solvers For The Boolean Satisfiability Problem: An Exploration, Nicole Nelson

Theses and Dissertations

The Boolean Satisfiability problem (SAT) is one of the most extensively researched NP-complete problems in Computer Science. This thesis focuses on the design of feasible solvers for this problem. A SAT problem instance is a formula in propositional logic. A SAT solver attempts to find a solution for the formula. Our research focuses on a newer solver paradigm, hybrid solvers, where two solvers are combined in order to gain the benefits from both solvers in the search for a solution. Our hybrid solver, AmbSAT, combines two well-known solvers: the systematic Davis-Putnam-Logemann-Loveland solver (DPLL) and the stochastic WalkSAT solver. AmbSAT's design …


Investigation Of Low-Stress Silicon Nitride As A Replacement Material For Beryllium X-Ray Windows, David B. Brough Dec 2012

Investigation Of Low-Stress Silicon Nitride As A Replacement Material For Beryllium X-Ray Windows, David B. Brough

Theses and Dissertations

The material properties of low stress silicon nitride make it a possible replacement material for beryllium in X-ray windows. In this study, X-ray windows made of LPCVD deposited low stress silicon nitride are fabricated and characterized. The Young's modulus of the LPCVD low stress silicon nitride are characterized and found to be 226±23 GPa. The residual stress is characterized using two different methods and is found to be 127±25 MPa and 141±0.28 MPa. Two support structure geometries for the low stress silicon nitride X-ray windows are used. X-ray windows with thicknesses of 100 nm and 200 nm are suspended on …