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2017

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Articles 6871 - 6900 of 8353

Full-Text Articles in Engineering

Program Requirements: Complexity, Myths, Radical Change, And Lean Enablers, Bohdan W. Oppenheim Jan 2017

Program Requirements: Complexity, Myths, Radical Change, And Lean Enablers, Bohdan W. Oppenheim

Systems Engineering Faculty Works

This paper presents a comprehensive discussion on the difficulties of formulating good and stable requirements early in complex engineering programs and the consequences on program execution. Formal classical systems engineering and program management (CSEPM) methodology is based on the assumption that the knowledge to anticipate all interfaces and create good requirements exists early in the program, and that it is a matter of working out the details to build extremely complex devices such as satellites, aircraft, refineries, nuclear power plants, and high-speed rail. The author argues that classical systems engineering and program management works well only for well-understood systems, but …

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Projecting Regional Climate And Cropland Changes Using A Linked Biogeophysical-Socioeconomic Modeling Framework: 1 Model Description And An Equilibrium Application Over West Africa, Guiling Wang, Kazi Farzan Ahmed, Liangzhi You, Miao Yu, Jeremy S. Pal, Zhenming Ji Jan 2017

Projecting Regional Climate And Cropland Changes Using A Linked Biogeophysical-Socioeconomic Modeling Framework: 1 Model Description And An Equilibrium Application Over West Africa, Guiling Wang, Kazi Farzan Ahmed, Liangzhi You, Miao Yu, Jeremy S. Pal, Zhenming Ji

Civil and Environmental Engineering Faculty Works

Agricultural land use alters regional climate through modifying the surface mass, energy, and momentum fluxes; climate influences agricultural land use through their impact on crop yields. These interactions are not well understood and have not been adequately considered in climate projections. This study tackles the critical linkages within the coupled natural-human system of West Africa in a changing climate based on an equilibrium application of a modeling framework that asynchronously couples models of regional climate, crop yield, multimarket agricultural economics, and cropland expansion. Using this regional modeling framework driven with two global climate models, we assess the contributions of land …

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Lehmier Launch System, Dylan Lehmier 5248813 Jan 2017

Lehmier Launch System, Dylan Lehmier 5248813

Williams Honors College, Honors Research Projects

The Lehmier Launch System was designed to propel a 120lb rocket 30,000 feet. Creating 2150 psi of thrust and 27,500 N-s of total impulse, it is the largest rocket motor ever used by the Akronauts Rocket Design Team.

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Design And Implementation Of An Air Multiplier Fan For Pc, George Demian Jan 2017

Design And Implementation Of An Air Multiplier Fan For Pc, George Demian

Williams Honors College, Honors Research Projects

Mechanical engineering student (B.S.) senior design project. Conception, design (SolidWorks), 3D printing & processing, testing of a scaled down air multiplier "bladeless" fan within a computer chassis as a cooling solution.

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The Experimental Determination Of The Moment Of Inertia Of A Model Airplane, Michael Koken Jan 2017

The Experimental Determination Of The Moment Of Inertia Of A Model Airplane, Michael Koken

Williams Honors College, Honors Research Projects

The objective of this project is to suggest that the moment of inertia for irregular shaped objects can easily be determined experimentally. The objects considered in this experiment were a solid wooden block and a model airplane. To ensure that the method and configuration is sufficient a wooden block with known moments of inertia was first tested, and the results from the experiment were compared to the known and accepted values. For this particular experiment, the periods were determined by timing how long 10 oscillations lasted for 10 different trials, and then taking the average of those 10 trials to …

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Reducing The Interfacial Tension Of Magnetic Surfactants In Magnetic Fields, Rachel Anne Stanhope Jan 2017

Reducing The Interfacial Tension Of Magnetic Surfactants In Magnetic Fields, Rachel Anne Stanhope

Honors Theses

This thesis discusses the theory, experimental research methods, and findings of the effects that magnetic fields have on the interfacial tension of magnetic surfactant solutions. Analyzing how magnetic fields affect the properties of magnetic surfactants, including interfacial tension, is the first step to creating low energy, magnetic field induced separations to address the problem of growing energy demands for chemical and biological separations [1]. Surfactants are organic structures that contain both a hydrophilic head group and a hydrophobic tail, which aggregate toward the interface of solutions and decrease the interfacial tension until the critical micelle concentration is reached. Magnetic surfactants …

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Patterns Of Total Gaseous Mercury Variation Prior To And After Brownfield Remediation In Syracuse, Ny, Linghui Meng Jan 2017

Patterns Of Total Gaseous Mercury Variation Prior To And After Brownfield Remediation In Syracuse, Ny, Linghui Meng

Theses - ALL

Although mercury toxicity has been recognized for centuries, the atmospheric cycle of this element is still not fully understood. In order to obtain a better perspective of the dynamics of atmospheric mercury in urban areas, total gaseous mercury (TGM) was measured at a brownfield site at the Center of Excellence (CoE) in Syracuse NY from 2011 to 2016. The brownfield was removed on May 2015, and a parking lot was installed. For this study, I had a series of objectives including: (1) to understand vertical and temporal variations in TGM concentration; (2) investigate the influence of meteorological factors on TGM …

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A Material Characterization Of Two-Solution Bone Cement Containing Ethylene Glycol-Dimethacrylate As A Crosslinker, Michael John Wiegand Jan 2017

A Material Characterization Of Two-Solution Bone Cement Containing Ethylene Glycol-Dimethacrylate As A Crosslinker, Michael John Wiegand

Theses - ALL

Bone cements are primarily used for fixation of implants as well as dampening of mechanical loads between the implant and neighboring bone. Two-solution bone cements offer a variety of advantages over commercial powder-liquid compositions due to a reduction in porosity, which in turn leads to improved mechanical properties. The effectiveness of the material is limited by its mechanical properties due to a large mismatch in moduli and strength between the cement, bone, and implant. Two-solution bone cements modified with ethylene glycol-dimethacrylate (EG-DMA) as a crosslinker have been developed as an attempt to further improve the mechanical and thermal properties of …

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An Evaluation Of Capillary Flow Test For Determining The Pore Size Distribution Of Geotextiles And Establishing Correlations, Nuzhath Fatema Jan 2017

An Evaluation Of Capillary Flow Test For Determining The Pore Size Distribution Of Geotextiles And Establishing Correlations, Nuzhath Fatema

Theses - ALL

For the last four decades, geotextiles have been used extensively for the purpose of separation, filtration, drainage and soil reinforcement. The basic criteria that impact the behavior of a geotextile filter are soil retention, permeability, and clogging potential. The ability of a geotextile filter to fulfill these requirements depends on the pore sizes and pore size distribution. There are numerous techniques to measure the pore sizes of a geotextile, but not all of them are widely accepted. In the USA, two standard methods of measuring the largest pore size of a geotextile have been accepted, the Dry sieving test (ASTM …

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Bragg Gratings In Polarization Maintaining Optical Fiber As Three Dimensional Strain Sensor, Joel Quintana Jan 2017

Bragg Gratings In Polarization Maintaining Optical Fiber As Three Dimensional Strain Sensor, Joel Quintana

Open Access Theses & Dissertations

Fiber-Bragg Gratings (FBG) for Structural Health Monitoring (SHM) have been studied extensively as they offer electrically passive operation, electromagnetic interference (EMI) immunity, high sensitivity and multiplexing as compared to conventional electric strain sensors. FBG sensors written within polarization maintaining (PM) optical fiber offer ad- ditional dimensions of strain measurement, greatly reducing the number of sensors needed to properly monitor a structure. This reduction however, adds complexity to the dis- crimination of the sensorâ??s optical response to its corresponding applied strains. This Dissertation defines the set of algorithms needed to measure planar strain using PM-FBGs exclusively. It defines the minimum number …

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Optimization Of Collagen Microneedle Using Taguchi Method, Abhilash Aditya Jan 2017

Optimization Of Collagen Microneedle Using Taguchi Method, Abhilash Aditya

Open Access Theses & Dissertations

Research is conducted to create dissolving collagen microneedles and to optimize the parameters for close to perfect dimension microneedles. A collagen microneedle patch has been developed with a micro-manufacturing process (micro-molding process). The collagen microneedles, varying in length from 300 to 600-μm may reach different targeted layers of the skin depending on the application. As the microneedles penetrate the skin they dissolve, delivering collagen through the epidermis. Such addition of collagen directly to the dermis layers allows it to be absorbed, increasing skin's strength and resilience, since it is one of the natural components of the younger looking skin. This …

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An In-Depth Evaluation Of Shear Box Compactor For Hot Mix Asphalt, Isaac Jaime Aguilar Jan 2017

An In-Depth Evaluation Of Shear Box Compactor For Hot Mix Asphalt, Isaac Jaime Aguilar

Open Access Theses & Dissertations

Asphalt pavement is present in each roadway in every town or city today and it is paramount to properly design pavement to efficiently reduce its deterioration. To determine how pavement fails, pavement specimens prepared in the laboratory undergo performance tests which demonstrate the pavements strength and durability. Performance tests require little variability from compacted specimens, and it is critical to have a compaction method which is similar to field compaction and produces homogenous specimens. Currently, laboratory performance test specimens are obtained with the Superpave Gyratory Compactor (SGC). That device has few similarities to the rolling compactor, which performs the actual …

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Quasi-Static Fracture Toughness Testing Of 7075 Aluminum For Spacecraft Separation Joint Applications, Ilse Alcantara Jan 2017

Quasi-Static Fracture Toughness Testing Of 7075 Aluminum For Spacecraft Separation Joint Applications, Ilse Alcantara

Open Access Theses & Dissertations

Separation joint systems are zero fault tolerant systems that have been used in complex aerospace applications such as vehicle stage separation and payload fairing removal. The structural members of separation joint systems must be able to withstand flight loads, but then completely fracture for instantaneous separation when an explosive is activated. The complex geometry and loading conditions of the structural member create a complicated stress state consisting of mixed tension and shear. A need exists to measure the fracture toughness of the material to ensure it will not support loads intended to fracture and measure its sensitivity to other variables, …

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Studies Of Air Pollutants And Their Impact On Respiratory And Cardiovascular Diseases In The El Paso Del Norte Region With Emphasis On Mobile Emissions, Juan Gustavo Arias Ugarte Jan 2017

Studies Of Air Pollutants And Their Impact On Respiratory And Cardiovascular Diseases In The El Paso Del Norte Region With Emphasis On Mobile Emissions, Juan Gustavo Arias Ugarte

Open Access Theses & Dissertations

Air pollution may cause different diseases, such as cardiovascular and lung diseases. Traffic is a major source of mobile emissions causing air pollution. Exhaust emissions from mobile sources (Emissions of Carbon Monoxide, Nitrogen Oxides and Hydrocarbons) and Non-exhaust (Brake and Tire) are complex mixtures of gases and dust, including a large number of ultrafine particles, especially in areas with high traffic density. Recent studies have shown high rates of morbidity and mortality in people exposed to these types of emissions because the fine and ultrafine particles can be transported from the respiratory airways to the organs, thus contributing to increase …

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Characterization & Extraction Of Extracellular Matrix From Porcine Adipose Tissue, Rahulkumar Kantibhia Bhoi Jan 2017

Characterization & Extraction Of Extracellular Matrix From Porcine Adipose Tissue, Rahulkumar Kantibhia Bhoi

Open Access Theses & Dissertations

Tissue in particular extracellular matrix(ECM) plays a vital role in the growth and the function of each cell types and promote tissue regeneration and repair an impair organs. Many techniques have been developed so far to decellularized porcine tissue for the purpose to use as regenerative medicine and in tissue engineering. We aimed to optimized a method to decellularized porcine tissue while effectively eliminating xenogeneic epitopes, lipids and to retain necessary component of it intact without disrupting ECM. We have developed 2-week protocol to optimize well preserved ECM component that may keep xenogeneic biomaterial for tissue engineering and regenerative medicine. …

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Strategies For Improving Labor Productivity In Construction Companies, Lakew G. Buli Jan 2017

Strategies For Improving Labor Productivity In Construction Companies, Lakew G. Buli

Walden Dissertations and Doctoral Studies

Even with advanced technology and new project management methodologies, construction company leaders continue to face challenges to improve labor productivity. This multiple case study was an exploration of the strategies that construction company leaders use to improve labor productivity in Doha, Qatar. The case population consisted of 6 construction company leaders operating in Doha, Qatar, who successfully identified and implemented strategies to improve labor productivity. The conceptual framework for this study was the expectancy theory. The data collection process included semistructured interviews and company documentation. Data were compiled and organized, disassembled into fragments, reassembled into a sequence of groups, and …

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Experiences Of Public Agency Managers When Making Outsourcing Decisions, Shakeel Baig Jan 2017

Experiences Of Public Agency Managers When Making Outsourcing Decisions, Shakeel Baig

Walden Dissertations and Doctoral Studies

Managers in state transportation agencies in the United States must frequently choose between using the talents and abilities of in-house staff or outsourcing for road and bridge design projects. Budgetary crises have strongly affected funding for transportation infrastructure. Facing budgetary pressures to suppress costs, managers must frequently make the choice of outsourcing a project or performing it in-house. Yet, decision-making models for these decisions are inadequate. The purpose of this phenomenological study was to explore and describe the lived experiences of public agency managers when making decisions to outsource the core government functions such as road and bridge design projects. …

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Scheduling Strategies For Construction Project Managers Toward On Time Delivery, Paul Shamp Jan 2017

Scheduling Strategies For Construction Project Managers Toward On Time Delivery, Paul Shamp

Walden Dissertations and Doctoral Studies

Construction management projects involve complex, dynamic environments resulting in uncertainty and risk, compounded by demanding time constraints. Research indicated project managers have struggled to identify best practices for scheduling construction projects via critical path methodologies while searching for tools to increase timely job completions and budget profits. The purpose of this single case study was to explore the strategies that construction project managers used to manage scheduled construction project delivery on time. The constructivist philosophical worldview was used as the framework for this study. Data were collected from semistructured interviews from 7 project managers from 5 different construction companies selected …

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Recruitment Strategies For Manufacturers In Northwest Louisiana, Markey W. Pierre Jan 2017

Recruitment Strategies For Manufacturers In Northwest Louisiana, Markey W. Pierre

Walden Dissertations and Doctoral Studies

Acquiring information about successful human resources strategies that help to effectively recruit skilled labor is critical for manufacturers. Manufacturing is the backbone of the United States, yet 6 of 10 skilled labor jobs are unfilled because traditional methods and strategies used by human resource leaders to recruit are inadequate. Guided through the lens of strategic human resource management and using the concepts and views of resource-based theory, the purpose of this multiple case study was to explore strategies that manufacturing human resource professionals use to successfully recruit skilled labor in Northwest Louisiana. The data collection for this case study was …

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Development Of High Efficiency Dry Powder Inhalers For Use With Spray Dried Formulations, Dale Farkas Jan 2017

Development Of High Efficiency Dry Powder Inhalers For Use With Spray Dried Formulations, Dale Farkas

Theses and Dissertations

Dry powder inhalers (DPIs) are advantageous for delivering medication to the lungs for the treatment of respiratory diseases because of the stability of the powders, relative low cost, synchronization of inhalation and dose delivery, and many design options that can be used for optimization. However, currently marketed DPIs are very inefficient in delivering medications to the lungs. This study has developed multiple new high efficiency DPIs for use with spray dried excipient enhanced growth (EEG) powder formulations based on the following platforms: capsule-based for oral inhalation, high-dose for oral inhalation, inline with 3D rod array dispersion, and inline with capillary …

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Development Of An Electrospun And 3d Printed Cellular Delivery Device For Dermal Wound Healing, Ryan M. Clohessy Jan 2017

Development Of An Electrospun And 3d Printed Cellular Delivery Device For Dermal Wound Healing, Ryan M. Clohessy

Theses and Dissertations

The goal of this research was to develop a system of individualized medicine that could be applied to dermal wounds serving as a wound dressing and synthetic extracellular matrix while delivering stem cells to the wound bed. First, fabrication parameters for electrospinning polymer fibers were determined. This involved evaluating fiber morphology with respect to polymer selection and solution concentration. Next, construct fabrication was examined to produce an integrated void space, or cargo area, suitable to maintain stem cells. In vitro studies to ensure stem cell viability and phenotype were conducted, and results supported the notion that cells could be administered …

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Efficient Reasoning Algorithms For Fragments Of Horn Description Logics, David Carral Jan 2017

Efficient Reasoning Algorithms For Fragments Of Horn Description Logics, David Carral

Browse all Theses and Dissertations

We characterize two fragments of Horn Description Logics and we define two specialized reasoning algorithms that effectively solve the standard reasoning tasks over each of such fragments. We believe our work to be of general interest since (1) a rather large proportion of real-world Horn ontologies belong to some of these two fragments and (2) the implementations based on our reasoning approach significantly outperform state-of-the-art reasoners. Claims (1) and (2) are extensively proven via empirically evaluation.

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Novel Implementation Of Finite Field Multipliers Over Gf(2m) For Emerging Cryptographic Applications, Nazeem Basha Shaik Jan 2017

Novel Implementation Of Finite Field Multipliers Over Gf(2m) For Emerging Cryptographic Applications, Nazeem Basha Shaik

Browse all Theses and Dissertations

Cryptographic and coding theory algorithms use arithmetic operations over finite fields. Finite field multiplications over GF(2m) are critical components for these systems. Well known irreducible polynomials are all-one-polynomials (AOP), equally spaced polynomial (ESP), trinomial and pentanomial. Due to its simple structure, AOP based multiplica- tion is easy to implement and hence the AOP based multiplication of variable length can be used as a standard computation core. In this thesis, first of all, we employ low register complexity AOP based systolic multiplication core to propose multiplication over GF(2m) based on NIST recommended pentanomials. The proposed parallel and serial ar- chitectures use …

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Analysis And Design Of High-Frequency Soft-Switching Dc-Dc Converter For Wireless Power Charging Applications, Abhishek V. Danekar Jan 2017

Analysis And Design Of High-Frequency Soft-Switching Dc-Dc Converter For Wireless Power Charging Applications, Abhishek V. Danekar

Browse all Theses and Dissertations

Wireless power transfer (WPT) technology is becoming attractive in a wide variety of applications such as electric-vehicle charging, induction heating, charging portable applications, industrial robots, and biomedical implants. Recent studies have shown various techniques to implement wireless power transfer and these techniques differ based on the type of applications. For example, for electric vehicle charging, the power levels are in the range 5 kW to 25 kW and the operating frequency is in the range 70 kHz to 110 kHz. On the other hand, for consumer applications, the power levels vary from a few watts to hundreds of watts and …

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Assessing Effectiveness Of Information Presentation Using Wearable Augmented Display Device For Emergency Response, Sriram Raju Chandran Jan 2017

Assessing Effectiveness Of Information Presentation Using Wearable Augmented Display Device For Emergency Response, Sriram Raju Chandran

Browse all Theses and Dissertations

Small screen wearable devices are becoming ubiquitous in the medical field; especially in the fields of surgery and trauma care. Technological intervention that supports data transfer of sending summary of the patient vitals through the transfer of care would be of great benefit to trauma care department. This research focuses on information presentation for wearable augmented reality device to improve human decision making during transfer of care for emergency response, and to improve user experience and reduce cognitive workload. Google Glass ™ device acts as heads up display for users, in this case being medical responders in hospital trauma care. …

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Multi-Class Classification Of Textual Data: Detection And Mitigation Of Cheating In Massively Multiplayer Online Role Playing Games, Naga Sai Nikhil Maguluri Jan 2017

Multi-Class Classification Of Textual Data: Detection And Mitigation Of Cheating In Massively Multiplayer Online Role Playing Games, Naga Sai Nikhil Maguluri

Browse all Theses and Dissertations

The success of any multiplayer game depends on the player’s experience. Cheating/Hacking undermines the player’s experience and thus the success of that game. Cheaters, who use hacks, bots or trainers are ruining the gaming experience of a player and are making him leave the game. As the video game industry is a constantly increasing multibillion dollar economy, it is crucial to assure and maintain a state of security. Players reflect their gaming experience in one of the following places: multiplayer chat, game reviews, and social media. This thesis is an exploratory study where our goal is to experiment and propose …

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Identification Of Novel Ligands And Structural Requirements For Heterodimerization Of The Liver X Receptor Alpha, Shimpi Bedi Jan 2017

Identification Of Novel Ligands And Structural Requirements For Heterodimerization Of The Liver X Receptor Alpha, Shimpi Bedi

Browse all Theses and Dissertations

LXRs, LXRa (NR1H3) and LXRß (NR1H2), are ligand-activated transcription factors that are members of the nuclear receptor superfamily. Oxysterols and nonsteroidal synthetic compounds bind directly to LXRs and influence the expression of LXR dependent genes. The use of murine models and LXR-selective agonists have established the important role of LXRs as sterol sensors that govern the absorption, transport, and catabolism of cholesterol. Upon activation, these receptors have been shown to increase reverse cholesterol transport from the macrophage back to the liver to aid in the removal of excess cholesterol. Not surprisingly, LXR dysregulation is a feature of several human diseases, …

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Sched-Its: An Interactive Tutoring System To Teach Cpu Scheduling Concepts In An Operating Systems Course, Bharath Kumar Koya Jan 2017

Sched-Its: An Interactive Tutoring System To Teach Cpu Scheduling Concepts In An Operating Systems Course, Bharath Kumar Koya

Browse all Theses and Dissertations

Operating systems is an essential course in computer science curriculum, which helps students to develop a mental model of how computer operating systems work. The internal mechanisms and processes of an operating system (OS) are often complex, non-deterministic and intangible which makes them difficult for students to understand. One such concept is central processing unit (CPU) scheduling. CPU scheduling forms the basis of the multiprogramming in an OS. In practice, OS courses involve classroom lectures describing high-level abstractions of the concepts, and students complete programming assignments to apply the material in a more concrete way. Depending on the programming assignments, …

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A Framework For Centralizing Inventory In Pharmaceutical Supply Chains, Kerry Kathleen Ward Jan 2017

A Framework For Centralizing Inventory In Pharmaceutical Supply Chains, Kerry Kathleen Ward

Browse all Theses and Dissertations

Effectively choosing the location of inventory in a pharmaceutical supply chain is central to the mission of pharmaceutical distributors. These supply chains are a critical backbone to the healthcare delivery process: the distributors must deliver products to pharmacies, hospitals and retailers at low cost and with a high level of reliability. This thesis provides a method for analyzing demand data to gain insight on the value of centralizing the inventory into either a hub-and-spoke or national network for a pharmaceutical distribution company. Demand data is analyzed using an off-the-shelf analysis tool as well as a new tool developed in SQL …

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An Optimization Compiler Framework Based On Polyhedron Model For Gpgpus, Lifeng Liu Jan 2017

An Optimization Compiler Framework Based On Polyhedron Model For Gpgpus, Lifeng Liu

Browse all Theses and Dissertations

General purpose GPU (GPGPU) is an effective many-core architecture that can yield high throughput for many scientific applications with thread-level parallelism. However, several challenges still limit further performance improvements and make GPU programming challenging for programmers who lack the knowledge of GPU hardware architecture. In this dissertation, we describe an Optimization Compiler Framework Based on Polyhedron Model for GPGPUs to bridge the speed gap between the GPU cores and the off-chip memory and improve the overall performance of the GPU systems. The optimization compiler framework includes a detailed data reuse analyzer based on the extended polyhedron model for GPU kernels, …

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