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

Engineering Commons

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

University of Massachusetts Amherst

Masters Theses

2016

Discipline
Keyword

Articles 1 - 25 of 25

Full-Text Articles in Engineering

Investigate The Interactions Between Silver Nanoparticles And Spinach Leaf By Surface Enhanced Raman Spectroscopic Mapping, Zhiyun Zhang Nov 2016

Investigate The Interactions Between Silver Nanoparticles And Spinach Leaf By Surface Enhanced Raman Spectroscopic Mapping, Zhiyun Zhang

Masters Theses

Owing to their increasing application and potential toxicity, engineered nanoparticles (ENPs) have been considered as a potential agricultural contaminant that may pose unknown risk to human beings. However, many techniques require invasive and complicated sample preparation procedures to detect and characterize engineered nanomaterials in complex matrices. In the first part of this thesis, we present a non-destructive and label-free approach based on surface enhanced Raman spectroscopic (SERS) mapping technique to qualitatively detect and characterize gold nanoparticles (AuNPs), on and in spinach leaves in situ. We were able to detect the clearly enhanced signals from AuNPs at 15 to 125 nm …


Live Load Distribution Factors For Horizontally Curved Concrete Box Girder Bridges, Mohammed Zaki Nov 2016

Live Load Distribution Factors For Horizontally Curved Concrete Box Girder Bridges, Mohammed Zaki

Masters Theses

Live load distribution factors are used to determine the live-load moment for bridge girder design when a two dimensional analysis is conducted. A simple, analysis of bridge superstructures are considered to determine live-load factors that can be used to analyze different types of bridges. The distribution of the live load factors distributes the effect of loads transversely across the width of the bridge superstructure by proportioning the design lanes to individual girders through the distribution factors.

This research study consists of the determination of live load distribution factors (LLDFs) in both interior and exterior girders for horizontally curved concrete box …


Variation Aware Placement For Efficient Key Generation Using Physically Unclonable Functions In Reconfigurable Systems, Shrikant S. Vyas Nov 2016

Variation Aware Placement For Efficient Key Generation Using Physically Unclonable Functions In Reconfigurable Systems, Shrikant S. Vyas

Masters Theses

With the importance of data security at its peak today, many reconfigurable systems are used to provide security. This protection is often provided by FPGA-based encrypt/decrypt cores secured with secret keys. Physical unclonable functions (PUFs) use random manufacturing variations to generate outputs that can be used in keys. These outputs are specific to a chip and can be used to create device-tied secret keys. Due to reliability issues with PUFs, key generation with PUFs typically requires error correction techniques. This can result in substantial hardware costs. Thus, the total cost of a $n$-bit key far exceeds just the cost of …


Numerical Simulation Of High Velocity Impact Of A Single Polymer Particle During Cold Spray Deposition, Sagar P. Shah Nov 2016

Numerical Simulation Of High Velocity Impact Of A Single Polymer Particle During Cold Spray Deposition, Sagar P. Shah

Masters Theses

Abstract

The cold spray process is an additive manufacturing technology primarily suited for ductile metals, and mainly utilized in coating surfaces, manufacturing of freeform parts and repair of damaged components. The process involves acceleration of solid micro-particles in a supersonic gas flow and coating build-up by bonding upon high velocity impact onto a substrate. Coating deposition relies on the kinetic energy of the particles. The main objective of this study was to investigate the mechanics of polymer cold spray process and deformation behavior of polymers to improve technological implementation of the process.

A finite element model was created to simulate …


A Soft Multiple-Degree Of Freedom Load Cell Based On The Hall Effect, Qiandong Nie Nov 2016

A Soft Multiple-Degree Of Freedom Load Cell Based On The Hall Effect, Qiandong Nie

Masters Theses

The goal of this thesis is to develop a soft multiple-degree-of-freedom (multi-DOF) load cell that is robust and light weight for use in robotics applications to sense three axes of force and a single axis of torque. The displacement of the magnet within the elastomer changes the magnetic flux density which is sensed by two 3-axis Hall effect sensors. Experimental measurements of magnetic flux density within the area of interest were used to formulate analytic expressions that relate magnet field strength to the position of the magnet. The displacement and orientation measurement and the material properties of the elastomer are …


Intent Recognition Of Rotation Versus Translation Movements In Human-Robot Collaborative Manipulation Tasks, Vinh Q. Nguyen Nov 2016

Intent Recognition Of Rotation Versus Translation Movements In Human-Robot Collaborative Manipulation Tasks, Vinh Q. Nguyen

Masters Theses

The goal of this thesis is to enable a robot to actively collaborate with a person to move an object in an efficient, smooth and robust manner. For a robot to actively assist a person it is key that the robot recognizes the actions or phases of a collaborative tasks. This requires the robot to have the ability to estimate a person’s movement intent. A hurdle in collaboratively moving an object is determining whether the partner is trying to rotate or translate the object (the rotation versus translation problem). In this thesis, Hidden Markov Models (HMM) are used to recognize …


Extrinsic Effects On Heat And Electron Transport In Two-Dimensional Van-Der Waals Materials- A Boltzmann Transport Study, Arnab K. Majee Nov 2016

Extrinsic Effects On Heat And Electron Transport In Two-Dimensional Van-Der Waals Materials- A Boltzmann Transport Study, Arnab K. Majee

Masters Theses

Two-dimensional van der Waals materials have been a subject of intense research interest in recent years. High thermal conductivity of graphene can be utilized for many thermal management applications. In spite of possessing very high electron mobility, graphene can’t be used as transistors because of the absence of band gap; however transition metal dichalcogenides are another class of two-dimensional van der Waals materials with inherent band gap and show a great promise for future nanoelectronic applications. But in order to tailor these properties for commercial applications, we should develop a better understanding of the effect of extrinsic factors like size, …


Infrastructure-Free Secure Pairing Of Mobile Devices, Chunqiu Liu Nov 2016

Infrastructure-Free Secure Pairing Of Mobile Devices, Chunqiu Liu

Masters Theses

Mobile devices have advanced tremendously during the last ten years and have changed our daily life in various ways. Secure pairing of mobile devices has become a significant issue considering the huge quantity of active mobile device connections and mobile traffic. However, current commonly used file sharing mobile applications rely on servers completely that are always targeted by attackers. In this thesis work, an innovative mechanism is proposed to generate symmetric keys on both mobile devices independently from a shared movement in arbitrary pattern, which means no server needs to be involved and no data exchange needed. A secret wireless-communication …


Protecting Controllers Against Denial-Of-Service Attacks In Software-Defined Networks, Jingrui Li Nov 2016

Protecting Controllers Against Denial-Of-Service Attacks In Software-Defined Networks, Jingrui Li

Masters Theses

Connection setup in software-defined networks (SDN) requires considerable amounts of processing, communication, and memory resources. Attackers can target SDN controllers defense mechanism based on a proof-of-work protocol. This thesis proposes a new protocol to protect controllers against such attacks, shows implementation of the system and analyze the its performance. The key characteristics of this protocol, namely its one-way operation, its requirement for freshness in proofs of work, its adjustable difficulty, its ability to work withmultiple network providers, and its use of existing TCP/IP header fields, ensure that this approach can be used in practice.


Improving Efficiency Of Thermoelectric Devices Made Of Si-Ge, Si-Sn, Ge-Sn, And Si-Ge-Sn Binary And Ternary Alloys, Seyedeh Nazanin Khatami Nov 2016

Improving Efficiency Of Thermoelectric Devices Made Of Si-Ge, Si-Sn, Ge-Sn, And Si-Ge-Sn Binary And Ternary Alloys, Seyedeh Nazanin Khatami

Masters Theses

Thermoelectric devices with the ability to convert rejected heat into electricity are widely used in nowadays technology. Several studies have been done to improve the efficiency of these devices. However, because of the strong correlation between thermoelectric properties (electrical conductivity, Seebeck coefficient, and thermal conductivity including lattice and electron counterpart), improving ZT has always been a challenging task. In this study, thermal conductivity of group IV-based binary and ternary alloys such as SiGe, SiSn, GeSn, and SiGeSn has been studied. Phonon Boltzmann Transport Equation has been solved in the relaxation time approximation including intrinsic and extrinsic (in the presence of …


Cold Gas Dynamic Spray – Characterization Of Polymeric Deposition, Trenton Bush Nov 2016

Cold Gas Dynamic Spray – Characterization Of Polymeric Deposition, Trenton Bush

Masters Theses

When a solid, ductile particle impacts a substrate at sufficient velocity, the resulting heat, pressure, and plastic deformation can produce bonding at the interface. The use of a supersonic gas flow to accelerate such particles is known as Cold Spray deposition. The Cold Spray process has been commercialized for some metallic materials, but further research is required to unlock the exciting material properties possible with polymeric compounds. In this work, a combined computational and experimental study a) simulated and optimized the nozzle flow conditions necessary to produce bonding in a polyethylene particle, b) developed and fabricated an experimental device, and …


Spotlight: An Information Service For The Cloud, Xue Ouyang Jul 2016

Spotlight: An Information Service For The Cloud, Xue Ouyang

Masters Theses

Infrastructure-as-a-Service cloud platforms are incredibly complex: they rent hundreds of different types of servers across multiple geographical regions under a wide range of contract types that offer varying tradeoffs between risk and cost. Unfortunately, the internal dynamics of cloud platforms are opaque in several dimensions. For example, while the risk of servers not being available when requested is critical in optimizing these risk-cost tradeoffs, it is not typically made visible to users. Thus, inspired by prior work on Internet bandwidth probing, we propose actively probing cloud platforms to explicitly learn such information, where each "probe'' is a request for a …


Tunable Plasmonic Thermal Emitter Using Metal-Coated Elastomeric Structures, Robert Zando Jul 2016

Tunable Plasmonic Thermal Emitter Using Metal-Coated Elastomeric Structures, Robert Zando

Masters Theses

This project was focused on the creation of a gold-coated grating structure capable of inducing a surface plasmon polariton within the mid-infrared region, enhancing emissions at specific wavelengths based on the grating periodicity. The grating structure was formed on a silicone elastomer, polydimethylsiloxane (PDMS), in order to give the structure, the ability to have the periodicity dimensions of the grating altered by applying a stress, thereby changing the location of the emission enhancement, giving the device the potential to be used as an infrared strain sensor.

Creation of the structure employed a top-down, micro-scale fabrication technique referred to as Direct …


Evaluating Features For Broad Species Based Classification Of Bird Observations Using Dual-Polarized Doppler Weather Radar, Sheila Werth Jul 2016

Evaluating Features For Broad Species Based Classification Of Bird Observations Using Dual-Polarized Doppler Weather Radar, Sheila Werth

Masters Theses

Wind energy is one of the fastest-growing segments of the world energy market; however, wind energy facilities can have detrimental effects on wildlife, especially birds and bats. The ability to monitor vulnerable species in the vicinity of proposed wind sites could enable site selection that favors more vulnerable species, but current monitoring tools lack this classification capability. This work analyzes polarimetric and Doppler measurements of migrating birds for species based variation.

A novel two stage feature extraction technique was developed to enable comparison between birds. Stage one involves mapping time changing radar measurements to the birds behavioral state in time …


Localization, Visualization And Evacuation Guidance System In Emergency Situations, Jingyan Tang Jul 2016

Localization, Visualization And Evacuation Guidance System In Emergency Situations, Jingyan Tang

Masters Theses

Urban search and rescue is needed for a variety of emergencies or disasters, including tornadoes, floods, dam failures, technological accidents, and terrorist activities. The efficiency to save people is becoming very important. With the development of the technology, people are trying to find a better way to help people get out of the dangerous places as soon as possible. DIORAMA system has been proposed to help with this problem and turns out very successful on improving efficiency during emergency situation. However, the current DIORAMA system is not perfect for all scenarios, for example, there are some outdoor environments do not …


A Haptic Surface Robot Interface For Large-Format Touchscreen Displays, Mark Price Jul 2016

A Haptic Surface Robot Interface For Large-Format Touchscreen Displays, Mark Price

Masters Theses

This thesis presents the design for a novel haptic interface for large-format touchscreens. Techniques such as electrovibration, ultrasonic vibration, and external braked devices have been developed by other researchers to deliver haptic feedback to touchscreen users. However, these methods do not address the need for spatial constraints that only restrict user motion in the direction of the constraint. This technology gap contributes to the lack of haptic technology available for touchscreen-based upper-limb rehabilitation, despite the prevalent use of haptics in other forms of robotic rehabilitation. The goal of this thesis is to display kinesthetic haptic constraints to the touchscreen user …


Modeling The Thermodynamics And Dynamics Of Fluids Confined In Three-Dimensionally Ordered Mesoporous (3dom) Carbon Materials, Anish Julius Desouza Jul 2016

Modeling The Thermodynamics And Dynamics Of Fluids Confined In Three-Dimensionally Ordered Mesoporous (3dom) Carbon Materials, Anish Julius Desouza

Masters Theses

Porous materials have application in adsorption based processes due to their high internal surface area and tailorable pore size. They find uses in fields such as catalysis, separation, biotechnology, and microelectronics. Fluids confined in such materials exhibit interesting behavior in regards to the condensation and evaporation mechanisms. Understanding study the behavior of fluids confined in these porous materials is necessary for the efficient design of these materials. The adsorption/desorption isotherm provides valuable information about the effect of network features like pore connectivity and pore size distribution on fluid behavior during pore condensation and evaporation. Such insight can be useful in …


Integrated Solar Technologies With Outdoor Pedestrian Bridge Superstructure Decking, Richard K. Racz Mar 2016

Integrated Solar Technologies With Outdoor Pedestrian Bridge Superstructure Decking, Richard K. Racz

Masters Theses

Solar technology has been a major topic in sustainable design for many years. In the last five years, however, the solar technology industry has seen a rapid growth in installations and technological advances in cell design. Combined with a rapidly declining overall system cost, the idea of introducing solar technology into a wider range of applications is becoming a focus for engineers and scientists around the world. So many variables which alter solar energy production, such as the sun and surrounding environment, determine whether a solar design is beneficial. This thesis presents a bridge deck surface integrated with solar cells …


Aircraft Demand Forecasting, Kayla M. Monahan Mar 2016

Aircraft Demand Forecasting, Kayla M. Monahan

Masters Theses

This thesis aims to forecast aircraft demand in the aerospace and defense industry, specifically aircraft orders and deliveries. Orders are often placed by airline companies with aircraft manufacturers, and then suddenly canceled due to changes in plans. Therefore, at some point during the three-year lead time, the number of orders placed and realized deliveries may be quite different. As a result, orders and deliveries are very difficult to predict and are influenced by many different factors. Among these factors are past trends, macroeconomic indicators as well as aircraft sales measures. These predictor variables were analyzed thoroughly, then used with time …


Developing An Ecological Sanitation Transect, Ian Kolesinskas Mar 2016

Developing An Ecological Sanitation Transect, Ian Kolesinskas

Masters Theses

A sanitation problem exists for people across the globe: basic human waste collection and treatment is inaccessible to much of the world’s population; and the status-quo gray infrastructure system of sanitation is unsustainable and unsuitable for widespread application. A paradigm shift is needed: this thesis makes the case for developing an Ecological Sanitation Transect to bring back the closed loop that connects consumption, waste excretion, sanitation, and food production. The Ecological Sanitation Transect is a synthesis of ecological sanitation, where human excreta is reused, and the urban transect, where development density is conceptualized along a continuum from rural to urban. …


Accelerated Iterative Algorithms With Asynchronous Accumulative Updates On A Heterogeneous Cluster, Sandesh Gubbi Virupaksha Mar 2016

Accelerated Iterative Algorithms With Asynchronous Accumulative Updates On A Heterogeneous Cluster, Sandesh Gubbi Virupaksha

Masters Theses

In recent years with the exponential growth in web-based applications the amount of data generated has increased tremendously. Quick and accurate analysis of this 'big data' is indispensable to make better business decisions and reduce operational cost. The challenges faced by modern day data centers to process big data are multi fold: to keep up the pace of processing with increased data volume and increased data velocity, deal with system scalability and reduce energy costs. Today's data centers employ a variety of distributed computing frameworks running on a cluster of commodity hardware which include general purpose processors to process big …


Strategies For Reducing Supplier Risk: Inputs Into The Supply Chain, Christopher A. Greene Mar 2016

Strategies For Reducing Supplier Risk: Inputs Into The Supply Chain, Christopher A. Greene

Masters Theses

There are many aspects to consider when managing an entire supply chain from procurement to fulfillment. Complex assemblies require hundreds of components, sourced from all corners of the globe, to come together in a synchronized fashion. Given the magnitude of the supply chain, high quality standards, and significantly increased outsourcing, there is a strong need to monitor supplier risk and quickly identify and mitigate potential problems. Moreover, the continuous pressure to reduce resources and pressure to cut costs, further increases the need for the development of procedures and tools that can quickly and efficiently address these potential supply chain risks. …


Processor Temperature And Reliability Estimation Using Activity Counters, Mayank Chhablani Mar 2016

Processor Temperature And Reliability Estimation Using Activity Counters, Mayank Chhablani

Masters Theses

With the advent of technology scaling lifetime reliability is an emerging threat in high-performance and deadline-critical systems. High on-chip thermal gradients accelerates localised thermal elevations (hotspots) which increases the aging rate of the semiconductor devices. As a result, reliable operation of the processors has become a challenging task. Therefore, cost effective schemes for estimating temperature and reliability are crucial. In this work we present a reliability estimation scheme that is based on a light-weight temperature estimation technique that monitors hardware events. Unlike previously pro- posed hardware counter-based approaches, our approach involves a linear-temporal-feedback estimator, taking into account the effects of …


Simulation Of 48-Hour Queue Dynamics For A Semi-Private Hospital Ward Considering Blocked Beds, Wei Chen Mar 2016

Simulation Of 48-Hour Queue Dynamics For A Semi-Private Hospital Ward Considering Blocked Beds, Wei Chen

Masters Theses

This thesis study evaluates access to care at an internal medicine unit with solely semi-private rooms at Baystate Medical Center (BMC). Patients are divided into two types: Type I patient consumes one bed; Type II patient occupies two beds or an entire semi-private room as a private space for clinical reasons, resulting in one empty but unavailable (blocked) bed per Type II patient. Because little data is available on blocked beds and Type II patients, unit-level hospital bed planning studies that consider blocked beds have been lacking. This thesis study bridges that gap by building a single-stream and a two-stream …


Seamless Application Delivery Using Software Defined Exchanges, Divyashri Bhat Mar 2016

Seamless Application Delivery Using Software Defined Exchanges, Divyashri Bhat

Masters Theses

One of the main challenges in delivering content over the Internet today is the absence of a centralized monitoring and control system [38]. Software Defined Networking has paved the way to provide a much needed control over network traffic. OpenFlow is now being standardized as part of the Open Networking Foundation, and Software Defined Exchanges (SDXes) provide a framework to use OpenFlow for multi-domain routing. Prototype deployments of Software Defined Exchanges have recently come into existence as a platform for Future Internet Architecture to eliminate the need for core routing technology used in today’s Internet. In this work, we look …