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Articles 4381 - 4410 of 11510

Full-Text Articles in Engineering

From Holographic Video Monitors To Optogenetic Probes: How Advancements To Leaky-Mode Modulator Technology Are Saving The World, Stephen Dalton Mclaughlin Jun 2018

From Holographic Video Monitors To Optogenetic Probes: How Advancements To Leaky-Mode Modulator Technology Are Saving The World, Stephen Dalton Mclaughlin

Theses and Dissertations

The research presented in this dissertation focuses on improvements made to lithium niobate leaky-mode modulators for both holographic video and optogenetic applications. The specific improvements found herein are: (1) characterization of leaky-mode modulators to decrease driver bandwidth to match that of commodity graphics processing units, (2) the implementation of surface relief gratings as input couplers to replace rutile prism coupling, (3) the addition of backside surface relief gratings to create an orthogonal output face for the leaky-mode modulator, and (4) the creation of superimposed surface relief gratings in lithium niobate to enable multiple wavelength coupling at a single input angle. …

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Design And Characterization Of Chiral Elastic Metamaterials, Sheng Sang Jun 2018

Design And Characterization Of Chiral Elastic Metamaterials, Sheng Sang

Theses and Dissertations

Metamaterial are materials engineered to have more than one property that cannot be observed in nature. Commonly, they are made from assemblies of multiple elements fashioned from composite materials such as metals or plastics. Due to its diverse application such as elastic wave cloaking, focusing and absorbing, elastic metamaterial has been the subject of intense experimental research and theoretical work in the past decades. Despite this large-scale effort, designs of the unit cell of the periodic structure for achieving negative elastic moduli are still needed. In this thesis, we first studied the wave phenomenon in lattice structure and materials with …

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Robust Pose Estimation Of A Robotic Navigation Aid For The Visually Impaired By Multimodal Data Fusion, He Zhang Jun 2018

Robust Pose Estimation Of A Robotic Navigation Aid For The Visually Impaired By Multimodal Data Fusion, He Zhang

Theses and Dissertations

For a visually impaired individual, it is a challenging task for him/her to plan and follow a path towards the destination. This task is referred to as wayfinding. In this paper, the functions of wayfinding are defined as localization (aka pose estimation) in an indoor environment and finding a way to get to the destination by using the location information. To address this issue, vision-based navigation systems that use a camera for pose estimation have been intensively studied. Several vision-based robotic navigation aids (RNAs) for the visually impaired have been developed. However, these RNAs are not reliable enough to assist …

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Web Aplikacioni Për Menaxhimin E Eventeve Në Kosovë, Fatlind Dautaj Jun 2018

Web Aplikacioni Për Menaxhimin E Eventeve Në Kosovë, Fatlind Dautaj

Theses and Dissertations

Një nga problemet më aktuale në Kosove është informimi rreth eventeve dhe vendeve turistike. Bazuar në këtë fakt, mungesa e informacioneve rreth eventeve dhe vendeve turistike ka bëre që të mos zhvillohet mjaftueshëm turizimi në Kosovë. Meqenëse informimi rreth turizmit deri me tani është bërë përmes broshurave, te cilat nuk mundë të permbanin mjaftushëm informacione, të cilat kishin ndikim jo të mire edhe për ambientin dhe që nuk ishin mjaft te sigurta se informacioni nga ato do të mundë të arrihej te përsonat e interesuar për event.Mirëpo me zhvillimin e këtij web aplikacioni atëherë gjithqka është lehtësuar pasi që informimi …

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Test Method For Predicting Failure Modes In Protective Films, Aubrey Jeanette Decker Jun 2018

Test Method For Predicting Failure Modes In Protective Films, Aubrey Jeanette Decker

Theses and Dissertations

In the business of packaging engineering, a large consumption of time is placed on evaluating new materials to provide cost savings to a company. This evaluation is made by using test methods such as those found in ASTM D4169-16, which helps to simulate shipping and distribution conditions. A key problem is that this test method can take up to multiple months, and sometimes years to complete. The apparatus created in this study allows for a comparison to be made between currently used films and prospective films in approximately ten hours. This allows for a prescreening of new films to be …

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Hardware And Software Improvements To A Low-Cost Holographic Video Monitor, Andrew August Henrie Jun 2018

Hardware And Software Improvements To A Low-Cost Holographic Video Monitor, Andrew August Henrie

Theses and Dissertations

The "Mark V" Holographic Video Monitor ("HoloMonitor") is a continuation of effort and accomplishments to produce a low-cost device capable of reproducing true full-color horizontal-parallax-only computer-generated holograms at typical video frame-rates. While other devices around the world may have greater capabilities, these devices are currently confined to laboratory settings due to their sheer complexity and expense. The aim of this project is to provide researchers and "tinkerers" with a device capable of recreating holographic effects in full color, respectable resolution, in real time, and at a comparatively low cost. The "Mark V" HoloMonitor is a closer representation of a consumer …

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Crash Severity Distributions For Life-Cycle Benefit-Cost Analysis Of Safety-Related Improvements On Utah Roadways, Conor Judd Seat Jun 2018

Crash Severity Distributions For Life-Cycle Benefit-Cost Analysis Of Safety-Related Improvements On Utah Roadways, Conor Judd Seat

Theses and Dissertations

The Utah Department of Transportation developed life-cycle benefit-cost analysis spreadsheets that allow engineers and analysts to evaluate multiple safety countermeasures. The spreadsheets have included the functionality to evaluate a roadway based on the 11 facility types from the Highway Safety Manual (HSM) with the use of crash severity distributions. The HSM suggests that local agencies develop crash severity distributions based on their local crash data. The Department of Civil and Environmental Engineering at Brigham Young University worked with the Statistics Department to develop crash severity distributions for the facility types from the HSM.The primary objective of this research was to …

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High Throughput Fpga Configuration Using A Custom Dma Configuration Controller, Peter William Zabriskie Jun 2018

High Throughput Fpga Configuration Using A Custom Dma Configuration Controller, Peter William Zabriskie

Theses and Dissertations

SRAM-based Field Programmable Gate Arrays (FPGAs) must be programmed with configuration data every time they are powered on. In addition to initially programming an FPGA, there are many other applications that require access to FPGA configuration memory such as partial reconfiguration, fault injection, and memory scrubbing. This thesis describes a system that provides high-speed, programmable configuration management for Xilinx FPGAs through external interfaces. This system is an improvement upon the JTAG Configuration Manager (JCM) previously created at BYU. The JCM consists of a custom I/O board paired with a MicroZed development board which includes a Xilinx ZYNQ SoC. This platform …

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Using Quantitative Mri To Measure Cartilage Health, Laurel Jane Hales Jun 2018

Using Quantitative Mri To Measure Cartilage Health, Laurel Jane Hales

Theses and Dissertations

Osteoarthritis (OA) is one of the leading causes of disability world-wide. It affects 12% of all Americans ages 25-74 [1]. One of the challenges with OA, is that there are currently no clinically viable methods to measure the health of the cartilage before cartilage loss. There are no ways to replace or heal the cartilage after it has been lost. It is known that the early stages of OA involve a decrease in the amount of glycosaminoglycans (GAG), one of the main molecules in cartilage. This decrease in GAG leads to a change in the fixed charge density of the …

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Adjustment Of Rapidscat Backscatter Measurements For Improved Radar Images, Garrett Scott Mcdonald Jun 2018

Adjustment Of Rapidscat Backscatter Measurements For Improved Radar Images, Garrett Scott Mcdonald

Theses and Dissertations

RapidScat is a spaceborne wind scatterometer mounted on the International Space Station (ISS). The RapidScat mission lasted from September 2014 to November 2016. RapidScat enables the measurement of diurnal patterns of sigma-0 measurements. This capability is possible because of the non-sun-synchronous orbit of the ISS, in which the local time of day (LTOD) of sigma-0 measurements gradually shifts over time in any given location. The ISS platform is a relatively unstable platform for wind scatterometers. Because of the varying attitude of the ISS, RapidScat experiences a constant variation of its pointing vector. Variations of the pointing vector cause variations in …

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Parametric Study On Multi-Story, Partially Grouted, Perforated, Masonry Shear Walls By Finite Element Analysis, Kyle Henry Chavez Jun 2018

Parametric Study On Multi-Story, Partially Grouted, Perforated, Masonry Shear Walls By Finite Element Analysis, Kyle Henry Chavez

Theses and Dissertations

In this study, parameters related to material properties, geometry, and external stimuli were examined individually to determine their influence on multi-story, partially grouted, perforated (openings), masonry shear walls using a finite element software FormWorks. The parameters studied were: the strength of grouted masonry prisms f'm,grouted; the strength of un-grouted (hollow) masonry prisms f'm,ungrouted; the ratio of mortar shear strength to masonry compressive strength; vertical and horizontal reinforcement ratios in terms of size and spacing of reinforcement; axial load; aspect ratio; and openings that were vertically and horizontally altered. To perform this study, finite element models were …

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Cost Model Evaluation For Large Scale Additive Manufacturing, Andrea Piazza Jun 2018

Cost Model Evaluation For Large Scale Additive Manufacturing, Andrea Piazza

Theses and Dissertations

Additive manufacturing (AM) is becoming a valuable option in medium to large scale manufacturing operations, due to the increasing technological advances and popularization of different techniques. Product development assembly costs can be greatly reduced with additive manufacturing, producing directly consumer-usable parts without the need of always rising labor costs. Entry level companies can bridge the gap between Tier 1 suppliers and Research & Development (R&D) businesses by utilizing the lower capital and reoccurring costs of modern additive manufacturing techniques, thereby avoiding the necessity for retooling and specialized machinery. The following study both explores the advantages and quantifies the cost factors, …

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Art To Engineering: Curved Folding And Developable Surfaces In Mechanism And Deployable Structure Design, Todd G. Nelson Jun 2018

Art To Engineering: Curved Folding And Developable Surfaces In Mechanism And Deployable Structure Design, Todd G. Nelson

Theses and Dissertations

This work investigates how curved-crease origami and the developable surfaces which compose it can be transitioned to engineering design. Methods for creating flexible, tailorable-property surfaces that function as thick panels in place of paper are presented. Concepts from curved-crease origami and developable surfaces that can describe and extend engineering applications are discussed and demonstrated. These concepts are particularly beneficial to applications where curved surfaces are integral to the function, deployability is desired, and planar manufacturing could be beneficial.The first part of this work uses arrays of compliant elements to create flexible-tailorable property surfaces. The key feature to these arrays is …

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Camera View Planning For Structure From Motion: Achieving Targeted Inspection Through More Intelligent View Planning Methods, Trent James Okeson Jun 2018

Camera View Planning For Structure From Motion: Achieving Targeted Inspection Through More Intelligent View Planning Methods, Trent James Okeson

Theses and Dissertations

Remote sensors and unmanned aerial vehicles (UAVs) have the potential to dramatically improve infrastructure health monitoring in terms of accuracy of the information and frequency of data collection. UAV automation has made significant progress but that automation is also creating vast amounts of data that needs to be processed into actionable information. A key aspect of this work is the optimization (not just automation) of data collection from UAVs for targeted planning of mission objectives. This work investigates the use of camera planning for Structure from Motion for 3D modeling of infrastructure. Included in this thesis is a novel multi-scale …

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Augmented Design Capabilities For Origami Tessellations, Janette Darlene Herron Jun 2018

Augmented Design Capabilities For Origami Tessellations, Janette Darlene Herron

Theses and Dissertations

Applying engineering principles to tessellation origami-based designs enables the control of certain design properties, such as flexibility, bending stiffness, mechanical advantage, shape conformance, and deployment motion. The ability to control these and other properties will enable augmented design capabilities in environments which currently limit the design to specific materials, including space, medicine, harsh environments, and scaled environments (such as MEMS applications). Other applications will be able to achieve more complex motions or better satisfy design and performance requirements.This research demonstrates augmented design capabilities of origami tessellations in engineering design in rigid-foldable and non-rigid-foldable applications. First, a method to determine Poisson's …

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Suitability Of The Kalina Cycle For Power Conversion From Pressurized Water Reactors, Jack Ryan Webster Jun 2018

Suitability Of The Kalina Cycle For Power Conversion From Pressurized Water Reactors, Jack Ryan Webster

Theses and Dissertations

The primary objective of this work is to determine the Kalina cycle's suitability for thermal power conversion from a pressurized water reactor. Several previous papers have examined this application, but these either lack proof of concept or make unfeasible assumptions. This work expands current knowledge by simulating the Kalina cycle and comparing it to current pressurized water reactor Rankine cycles in order to identify which is more efficient. Prerequisite to the modeling is a simulation tool capable of modeling the thermodynamics of ammonia/water mixtures. Instead of using an existing program, a new one called Clearwater is used. This tool is …

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A Systematic Process For Implementing Mass Customization In Residential Preconstruction, Spencer J. Blaylock Jun 2018

A Systematic Process For Implementing Mass Customization In Residential Preconstruction, Spencer J. Blaylock

Theses and Dissertations

According to production process theory, customization is directly related to cost and inversely related to volume, efficiency, and productivity. However, customers generally desire products that are individually tailored to their wants and needs. For this reason, as residential contractors grow, they struggle to meet customers' demands for flexibility. This struggle to increase customization is not unique to the construction industry and many other industries have studied this problem in depth. While the inverse relationship between customization and cost is generally true, mass customization can enable increased customization with limited or no increased cost. The residential construction process employs many mass …

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Real-Time Feedback For In-Class Introductory Computer Programming Exercises, Ariana Dawn Sellers Jun 2018

Real-Time Feedback For In-Class Introductory Computer Programming Exercises, Ariana Dawn Sellers

Theses and Dissertations

Computer programming is a difficult subject to master. Introductory programming courses often have low retention and high failure rates. Part of the problem is identifying if students understand the lecture material. In a traditional classroom, a professor can gauge a class's understanding on questions asked during lecture. However, many struggling students are unlikely to speak up in class. To address this problem, recent research has focused on gathering compiler data from programming exercises to identify at-risk students in these courses. These data allow professors to intervene with individual students who are at risk and, after analyzing the data for a …

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Application Of Microwave And Ultrasonic Techniques For Defect Detection In Pipes, Wissam Muzher Alobaidi May 2018

Application Of Microwave And Ultrasonic Techniques For Defect Detection In Pipes, Wissam Muzher Alobaidi

Theses and Dissertations

Microwaves promulgate through a waveguide, reflecting off its inner surface, of course. It is known that any irregularity (discontinuity) in the surface will alter the course of the reflected signal, and that the reflected signal can be recaptured and processed algorithmically to generate a waveform characteristic of the discontinuity. The work of this dissertation is based in this phenomenon. The aim is to develop methods for detecting and then characterizing pipe wall thinning (PWT) discontinuities in pipes. The work includes both simulations and practical experiments. New possibilities were discovered as the work progressed. Prior work revealed a promising initial setup …

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An Investigation Of The Cortical Learning Algorithm, Anthony C. Samaritano May 2018

An Investigation Of The Cortical Learning Algorithm, Anthony C. Samaritano

Theses and Dissertations

Pattern recognition and machine learning fields have revolutionized countless industries and applications from biometric security to modern industrial assembly lines. The fields continue to accelerate as faster, more efficient processing hardware becomes commercially available. Despite the accelerated growth of the pattern recognition and machine learning fields, computers still are unable to learn, reason, and perform rudimentary tasks that humans and animals find routine. Animals are able to move fluidly, understand their environment, and maximize their chances of survival through adaptation - animals demonstrate intelligence. A primary argument in this thesis that we have not yet achieved a level of intelligence …

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Stealth Transmission In Free Space Optical Communication Systems Using Amplified Spontaneous Emission Noise, Youness Ergaibi May 2018

Stealth Transmission In Free Space Optical Communication Systems Using Amplified Spontaneous Emission Noise, Youness Ergaibi

Theses and Dissertations

One of the challenging real-world problems in the communication network is to secure the communication system that deals with a large data. Perhaps even a more challenging version of this scenario is when the channel that transmits the information is a wireless media. This thesis introduces a steganography technique to secure the physical layer of the communication system. It enhances the benefits by using optical communication rather than radio frequency (RF) communication, especially in terms of transmitting a large scale of data. This thesis demonstrates that we can transmit secure large information in free space (air) using steganography mechanism and …

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Perovskite Solar Cells Fabricated Via Scalable Dip Coating Methods, Joseph F. Iannello May 2018

Perovskite Solar Cells Fabricated Via Scalable Dip Coating Methods, Joseph F. Iannello

Theses and Dissertations

Perovskite solar cells present the possibility for less expensive electricity generation, through the use of low cost materials and fabrication methods relative to current silicon-based technology. Many current methods of fabricating thin film perovskite solar cells focus on spin-coating, which inherently lacks scalability due to particle conglomeration, poor uniformity over a larger area, and safety concerns. Dip-coating, an alternative to spin-coating, which is explored here addresses these issues which limit scalability. Each individual layer can be separately synthesized, deposited, and characterized, which leads towards scalability. Choosing only the best results from each independent layer allowed progress to the creation of …

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Kinematic Analysis Of Spinal Cord Injury Animals Treated With A Neurotrophin-Infused Scaffold And Body Weight Supported Treadmill Training, Alexander Herman May 2018

Kinematic Analysis Of Spinal Cord Injury Animals Treated With A Neurotrophin-Infused Scaffold And Body Weight Supported Treadmill Training, Alexander Herman

Theses and Dissertations

Spinal Cord Injury (SCI) is a condition that affects around 250,000 Americans with no cure. Existing treatments rely on physical therapies such as body weight support treadmill training (BWSTT). Treatments currently being researched include the use of implantable cells and biomaterials. Our study investigated the changes in locomotive gait and range of motion via a combinational treatment using a bioengineered scaffold [poly (N-isopropyl acrylamide) polyethylene glycol (PNIPAAm-g-PEG) with BDNF and NT-3] and rehabilitation training using BWSTT in a clinically relevant contusion SCI animal model. Five different groups of animals (Sham, Injury, BWSTT, Implant, and Combinational) were tested on a treadmill …

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Thermal Fluid Models Of A Hydrogel Delivery System For Pancreatic Cancer Treatment, Nesrine Bouhrira May 2018

Thermal Fluid Models Of A Hydrogel Delivery System For Pancreatic Cancer Treatment, Nesrine Bouhrira

Theses and Dissertations

Pancreatic cancer is one of the most devastating cancers with low survival rates. This disease is difficult to detect due to the pancreas's location deep within the body. Therefore, diagnoses are often made in the later stages, making treatment options more limited and difficult. It has been hypothesized that direct injection into the tumor would enhance drug effectivenes. Therefore, we examined the use of endoscopic ultrasound (EUS) combined with a fine needle injection to deliver a drug-eluding thermosensitive hydrogel directly into the tumor. Unfortunately normal body temperatures surrounding the EUS can warm the hydrogel drug combination beyond its phase transition …

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Impact Of Antenna Mutual Coupling, Propagation, And Nonreciprocity On Propagation-Based Key Establishment, Attiya Mahmood May 2018

Impact Of Antenna Mutual Coupling, Propagation, And Nonreciprocity On Propagation-Based Key Establishment, Attiya Mahmood

Theses and Dissertations

Propagation-based key establishment is a physical layer method for generating encryption keys based on two radios observing a reciprocal propagation channel. This work explores the impact of mutual coupling when communicating nodes are equipped with multiple antennas, multipath richness in the propagation environment, and practical limitations caused by the nonreciprocal nature of RF circuits on key establishment. First, network theory is used to formulate a model of a realistic communication system which incorporates transmit sources and receive loads, impedance matching networks, low-noise amplifiers (LNAs), mutually coupled antenna arrays, and a passive eavesdropper. Afterwards, a detailed analysis is performed to quantify …

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Applying Attribute-Based Encryption In Two-Way Radio Talk Groups: A Feasibility Study, Michael Andreas Gough May 2018

Applying Attribute-Based Encryption In Two-Way Radio Talk Groups: A Feasibility Study, Michael Andreas Gough

Theses and Dissertations

In two-way radio systems, talk groups are used to organize communication. Some situations may call for creating a temporary talk group, but there are no straightforward ways to do this. Making a new talk group requires programming radios off-line. Temporary groups can be created, but this requires inputting radio IDs which is tedious on a radio's limited controls. By describing group members using attributes, ciphertext-policy attribute-based encryption (CP-ABE) can be used to quickly create sub-groups of a talk group. This scheme requires fewer button presses and messages sent in the new talk group are kept secret. CP-ABE can be used …

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Impact Of Computer Tablets On General Aviation Flight Training, Anthony Saitabau Lolchoki May 2018

Impact Of Computer Tablets On General Aviation Flight Training, Anthony Saitabau Lolchoki

Theses and Dissertations

Over the past two decades, Electronic Flight Bags (EFBs) and Personal Electronic Devices (PEDs) have developed from flight publication storage devices hosted on modified laptop computers into fully interactive near-avionics-quality navigation equipment based on consumer-grade tablet computers. Broadly speaking, the Code of Federal Regulation (CFR) 14 regulates the use of this type of equipment for commercial airlines, commuter operations, and fractional ownership operators, but have neglected the General Aviation (GA) sector. Due, in part, to this lack of governance, little has been known about EFB use in GA. After using an internet-based survey, this study was conducted to examine whether …

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Design Of A Multidirectional Wear Testing Device For Simulating Wear Of Biocompatible Materials Used In Joint Implants, Carlos A. Rodriguez Betancourth May 2018

Design Of A Multidirectional Wear Testing Device For Simulating Wear Of Biocompatible Materials Used In Joint Implants, Carlos A. Rodriguez Betancourth

Theses and Dissertations

In the present work, a novel multidirectional pin-on-disc wear testing device designated CNC-POD (computer-numerical-control pin-on-disc) capable of replicating the cross-shear motions experienced by a prosthesis in vivo was designed and developed in the UTRGV in order to evaluate the wear resistance of new biomaterials. The CNC-POD consists of six temperature-controlled pin-on-disc stations mounted on a two-axis CNC table (X-Y). Each pin-on-disc station is load-programmable up to 510 Newtons (115 pounds). The CNC table allows the machine to reproduce a wide range of 2D patterns in millimeter scale on the six stations under a specific load. Friction force is measured during …

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Design Of A Low-Cost Capillary Electrophoresis Laser-Induced Fluorescence System: Lessons Learned When Trying To Build The Lowest Possible Cost System, Steven James Perry May 2018

Design Of A Low-Cost Capillary Electrophoresis Laser-Induced Fluorescence System: Lessons Learned When Trying To Build The Lowest Possible Cost System, Steven James Perry

Theses and Dissertations

Capillary electrophoresis laser-induced fluorescence (CE-LIF) is widely used to detect both the presence and concentration of fluorescently labeled biomolecules. In CE-LIF, a plug of sample fluid is electrophoretically driven down a microchannel using a high voltage applied between the opposite ends of the microchannel. Molecules of different sizes and charge states travel at different velocities down the channel. Laser light with a wavelength in the excitation band of the fluorophores is focused near the end of the channel. As each species of molecule passes through the laser spot, the fluorophores emit a fluorescence signal which is measured with an optical …

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Buffer Controlled Cache For Low Power Multicore Processors, Marven Calagos May 2018

Buffer Controlled Cache For Low Power Multicore Processors, Marven Calagos

Theses and Dissertations

This thesis proposes a buffered dual access mode cache to reduce power consumption in multicore caches for embedded systems. This cache is called Buffer Controlled Cache (BCC cache). The proposed scheme introduces a pre-cache buffer to determine how to access the cache. The proposed cache shows better prediction rates and lower power consumption than conventional caches, such as Phased cache and Way-prediction cache. For single core implementation, Simplescalar and Cacti simulators have been used for these simulations using SPEC2000 benchmark programs. The experimental results show that the proposed cache improves the power consumption by 37%-42% over the conventional caches. Multi2Sim …

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