Engineering Commons^™

A Gamos Plug-In For Geant4 Based Monte Carlo Simulation Of Radiation-Induced Light Transport In Biological Media, Adam K. Glaser, Stephen C. Kanick, Rongxiao Zhang, Pedro Arce, Brian W. Pogue

Dartmouth Scholarship

We describe a tissue optics plug-in that interfaces with the GEANT4/GAMOS Monte Carlo (MC) architecture, providing a means of simulating radiation-induced light transport in biological media for the first time. Specifically, we focus on the simulation of light transport due to the Čerenkov effect (light emission from charged particle's traveling faster than the local speed of light in a given medium), a phenomenon which requires accurate modeling of both the high energy particle and subsequent optical photon transport, a dynamic coupled process that is not well-described by any current MC framework. The results of validation simulations show excellent agreement with …

A Preliminary Discourse On Adhesion Of Nanofibers Derived From Electrospun Polymers, Pei Chen

Mechanical Engineering Faculty Research

To bio-mimic gecko’s foot hair, which possess high adhesion strength and can be re- usable for lifetime, fibrous membranes are fabricated by electrospinning to provide sufficient adhesion energy. Shaft-loaded blister test (SLBT) is firstly used to measure the work of adhesion between electrospun membrane and rigid substrate. Poly(vinylidene fluoride) (PVDF) were electrospun with an average fiber diameter of 333±59 nm. Commercial cardboard with inorganic coating was used to provide a model substrate for adhesion tests. In SLBT, the elastic response PVDF was analyzed and its adhesion energy measured. FEA model with cohesive layer is developed to evaluate the experiment results. …

End-Of-Life Management Of Crystalline Silicon Photovoltaic Module, Jun-Ki Choi

Mechanical and Aerospace Engineering Faculty Publications

PV manufacturing has been growing over the past 10 years and further annual growth of 15% is expected until 2020. A study on positioning a grand plan for solar power shows how vast PV arrays and other renewable energies can provide significant amount of electricity and total energy needs by 2050. Various new PV technologies have been introduced in the market and existing technologies have undergone further development. How all these developments will affect the fate of the end-of-life PV modules is uncertain. In addition, the market price of some rare earth materials utilized in the manufacturing of the various …

Uncertainty In Radar-Rainfall Composite And Its Impact On Hydrologic Prediction For The Eastern Iowa Flood Of 2008, Bong Chul Seo, Luciana K. Cunha, Witold F. Krajewski

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Key Points A significant potential source of error exists in mosaicked radar-rainfall maps. Different radar calibration offsets lead to misestimation of rainfall amounts. Systematic error in rainfall significantly affects hydrologic predictions. This study addresses a significant potential source of error that exists in radar-rainfall maps that are combined using data from multiple WSR-88D radars of the Next Generation Radar (NEXRAD) national network in the United States. This error stems from different radar calibration offsets that create a border within discontinuous rainfall fields at the equidistance zone among radars. The discontinuity in rainfall fields could lead to misestimation of rainfall over …

Professional Skills Portfolio For A Progressive Engineering Education, Dermot Mcgarthy, David Kennedy

Articles

At the 2013 launch of the return to work scheme, “Springboard” in Dublin, it was stated that employers were seeking staff with enhanced language, presentation, communication, coping, and team-working skills. Graduates without these skills were finding it more difficult to gain permanent employment and were more likely to find themselves out of work unless they developed these skills. Enhancing personal development skills in education requires a revision of existing programmes. Not alone will these skills open new doors of opportunity for those who have lost their jobs during the recession, but should help sustain them going forward. The education of …

A Performance Analysis Of Ws-* (Soap) And Restful Web Services For Implementing Service And Resource Orientated Architectures, Philip Markey, Gary Clynch

Conference Papers

The past number of years have seen the emergence of Service-Oriented Architectures as a dominant architecture for implementing enterprise scale distributed systems. Two main styles of SOA exist, namely SOAP based services and RESTful services. There has been much comment and debate on the pros and cons of each approach to implementing a SOA, a lot of which has surrounded the performance characterictcs of both approaches. In this paper, the authors presents the results of a performance analysis that was conducted on a set of test SOA scenarios implemented using both SOAP and RESTful approaches; in particular the caching capabilities …

Cooking Up The Optimal Baking Algorithm, Tony Burand, Michael Tetzlaff, Jacob Smith

Colloquy Undergraduate Research Journal

Many conventional rectangular baking pans have a problem in that they bake the corners of the batter faster than the rest of the pan. Circular baking pans eliminate this problem, but take up more space in the oven. We propose a solution that given weights for baking consistency and space efficiency based on the importance of each will provide the optimal baking pan shape. We have come up with an algorithm for sorting the pans of area A effectively and formed a model that describes the heat flow into the pan as well as the baking mix itself. The model …

An Overview Of U.S. Commuter Rail, Timothy J. Brock, Reginald R. Souleyrette

Kentucky Transportation Center Research Report

Planners view commuter rail as a means of managing urban sprawl, stimulating economic development and reducing the environmental impacts of transportation. Commuter rail systems, which use shared rights-of-way to connect suburban hubs with downtown urban centers, are beginning to have a large impact on the way people and freight move through US cities. Currently, there are 26 commuter rail systems operating in 29 major U.S. metropolitan areas. However, there is confusion among the general public and disagreement among transportation organizations as to what constitutes a commuter rail system and how to classify some rail systems. This research establishes a complete …

Multimodal Alternative Evaluation Us 60 (Versailles Road) Lexington, Ky: Final Report, Adam J. Kirk

Kentucky Transportation Center Research Report

The Versailles Road corridor is a major arterial into the heart of Lexington, KY, connecting the Bluegrass Airport, Keeneland, and the Bluegrass Parkway with downtown. In addition, the corridor serves as the most heavily used transit route within the city. Heavy pedestrian and bicycle usage also exist on the corridor making it one of the most vibrant and diverse multimodal corridors in the city if not the state. However, few improvements have been made for either automobile or other modes of transportation in recent years leading to a poor condition of some facilities and the need for improved and expanded …

Stormwater Pollution Treatment Bmp Discharge Structures, Miles F. Simmons

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Structural best management practices (BMPs) are used to capture and treat stormwater runoff. Most structural BMPs provide treatment by filtering runoff through a filter media or collecting it in a detention basin and slowly discharging it over an extended period of time to allow suspended solids and associated contaminants to settle out. The purpose of this study is to design an effective outlet structure that provides adequate filtration or slows discharge to 40 hours.

A model detention basin was constructed in the Civil Engineering Hydraulics Laboratory at the University of Nebraska-Lincoln (UNL) and two full scale outlet structures were tested …

Transient Liquid Phase Bonding Of Titanium-, Iron- And Nickel- Based Alloys, A. H. M. Esfakur Rahman

Theses and Dissertations

The operating temperature of land-based gas turbines and jet engines are ever-increasing to increase the efficiency, decrease the emissions and minimize the cost. Within the engines, complex-shaped parts experience extreme temperature, fatigue and corrosion conditions. Ti-based, Ni-based and Fe-based alloys are commonly used in gas turbines and jet engines depending on the temperatures of different sections. Although those alloys have superior mechanical, high temperature and corrosion properties, severe operating conditions cause fast degradation and failure of the components. Repair of these components could reduce lifecycle costs. Unfortunately, conventional fusion welding is not very attractive, because Ti reacts very easily with …

Transient Effects On Dynamic Torque For Butterfly Valves, Trevor N. Price

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Butterfly valves are versatile components widely used in hydraulic systems as shutoff and throttling valves. Butterfly valve components must be able to withstand the forces and torques that are generated with use. Dynamic torque data are usually obtained in a test lab for a variety of steady state flow conditions; however the dynamic torque under transient (unsteady flow) conditions may be significantly different than that found in the laboratory. If a valve is closed too fast, especially in long systems, large transient pressures are generated and travel as waves through the pipeline. These transient waves increase the pressure difference across …

Modeling The Liquid, Nasal, And Vowel Transitions Of North American English Using Linear Predictive Filters And Line Spectral Frequency Interpolations For Use In A Speech Synthesis System, Jacob G. Nieveen

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

A speech synthesis system with an original user interface is being developed. In contrast to most modern synthesizers, this system is not text to speech (TTS). This system allows the user to control vowels, vowel transitions, and consonant sounds through a simple 2-d vowel pad and consonant buttons. In this system, a synthesized glottal waveform is passed through vowel filters to create vowel sounds. Several filters were calculated from recordings of vowels using linear predictive coding (LPC). The rest of the vowels in the North American English vowel space were found using interpolation techniques with line spectral frequencies (LSF). The …

Development Of Standards, Objectives, And Curriculum Guide To Teach Basic Electronics For Utah Science Credit In Secondary School Education, Rick Pierce

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Recently, the Utah State Office of Education (USOE) has accepted Basic Electronics, Classification of Instructional Programs (CIP) code 47.0105, as an elective to fill the required third science credit for secondary education (grades 10-12) students. The current Utah state core standards and objectives used for curriculum development in the Basic Electronics classes are now inadequate, as they are more than 15 years old, and designed specifically for students pursuing a technical career path. A formatting change to the document was implemented in 2008, but the standards and objectives were not changed.
Students are subsequently being taught the fundamentals of technology …

Glycerin And The Market, Valentine Chijioke Mbamalu

Masters Theses and Doctoral Dissertations

Glycerin, a trihydric alcohol, had once enjoyed a good market value but, is now faced with global oversupply and this makes the market volatile. It is a byproduct of biodiesel production thought as an added value to biodiesel operations. It is now faced with an unpredictable market and probably oversupply as an outcome of increased biodiesel production. There are two types of glycerin market; the refined glycerin with its solid price and crude glycerin which is volatile. There are new applications for glycerin being developed or being implemented and it will be a source of strength to the market. This …

Intermediate Band Solar Cells Based On Inas Quantum Dots Embedded In Ingaas Quantum Well, Ramesh Vasan

Graduate Theses and Dissertations

Intermediate band solar cells based on quantum dots and quantum wells with anti-reflection coating are investigated in this thesis. The demand for high efficient solar cells as an alternate source of energy is the main motivation for this research project. Intermediate band solar cells based on quantum dots were the subject of intensive research in recent years. High power conversion efficiency was predicted from InAs/GaAs intermediate band solar cells as the presence of InAs quantum dots increased the absorption below the band gap of the host material.

In this thesis, an attempt has been made to further increase the absorption …

Tanker Acquisition: A Systems Engineering Perspective, Sarah Lynch, Alan R. Heminger, David D. Mattioda

Faculty Publications

A short examination of air refueling, specifically its past, present, and future, offers valuable insight into the developmental needs of this critical capability. This article seeks not only to showcase an appreciation for the roots of air refueling but also to high- light the requirement for sound systems engineering in conjunction with the creativity and willingness to take risks, as exhibited by our forefathers in the field. These attributes are vital to furthering air- refueling technologies and capabilities as well as refining the some- what flawed tanker-procurement process employed today.

Design And Fabrication Of Nanofluidic Systems With Integrated Sensing Electrodes For Rapid Biomolecule Characterization, Taylor Bradley Busch

Graduate Theses and Dissertations

A transparent nanofluidic system with embedded sensing electrodes was designed and fabricated by integrating Atomic Force Microscopy (AFM) nanolithography, Focused Ion Beam (FIB) milling and metal deposition, and standard microfabrication processing. The fabrication process started with the evaporation of chrome/gold (Cr/Au) onto a Pyrex 7740 wafer followed by photolithography and wet etching of the microchannels. The wafer was patterned a second time to form Au microelectrodes with 15-45 micrometer separation gaps in the nanochannel region. Sensing electrodes (up to one micron wide) were then deposited using FIB to bridge the gaps. The nanochannels were realized through both AFM nanolithography and …

The Geometry And Sensitivity Of Ion-Beam Sculpted Nanopores For Single Molecule Dna Analysis, Ryan Connor Rollings

Graduate Theses and Dissertations

In this dissertation, the relationship between the geometry of ion-beam sculpted solid-state nanopores and their ability to analyze single DNA molecules using resistive pulse sensing is investigated. To accomplish this, the three dimensional shape of the nanopore is determined using energy filtered and tomographic transmission electron microscopy. It is shown that this information enables the prediction of the ionic current passing through a voltage biased nanopore and improves the prediction of the magnitude of current drop signals when the nanopore interacts with single DNA molecules. The dimensional stability of nanopores in solution is monitored using this information and is improved …

Plasmonic Nanostructures For The Absorption Enhancement Of Silicon Solar Cells, Nathan Matthias Burford

Graduate Theses and Dissertations

In this work, computational investigation of plasmonic nanostructures was conducted using the commercial finite element electromagnetics solver Ansys® HFSS. Arrays of silver toroid nanoparticles located on the surface of an amorphous silicon thin-film absorbing layer were studied for particle sizes ranging from 20 nm to 200 nm in outer diameter. Parametric optimization by calculating an approximation of the photocurrent enhancement due to the nanoparticles was performed to determine optimal surface coverage of the nanoparticles. A comparison was made between these optimized nanotoroid arrays and optimized nanosphere arrays based on spectral absorption enhancement and potential photocurrent enhancement in an amorphous silicon …

Improvements In Microdialysis Sampling Extraction Efficiency Using Recycled Flow, Justin Cole Deaton

Graduate Theses and Dissertations

Incomplete recovery during microdialysis sampling is hindering important research in neurology, proteomics, and immunology. Although the current generalized solution, decreasing volumetric flow rates (Q), has been and will remain to be a useful strategy it has reached it's a physical limitation due to evaporation at the collection site. Consequently, many important signaling molecules, such as signaling proteins, remain difficult to study. It is more fundamental to consider relative recovery as a function of the interaction time between the perfusate and the environment surrounding the probe.

In this work an increase in relative recovery was predicted by a mathematical model. Using …

A Numerically Efficient Formulation For Time-Domain Electromagnetic- Semiconductor Cosimulation For Fast-Transient Systems, Quan Chen, Wim Schoenmaker, Guanhua Chen, Lijun Jiang, Ngai Wong

Electrical and Computer Engineering Faculty Research & Creative Works

We report recent progress in developing a numerically efficient formulation for electromagnetic-technology computer-aided design cosimulation for fast-transient computations. The difficulties underlying the currently existing transient formulation stemming from the vector potential-scalar potential (A-V) framework are analyzed. A time-domain electric field-scalar potential (E-V) framework is then developed via equation and variable transformations. This results in better-conditioned systems that are friendly to iterative solutions at fast switching times. Numerical examples show that the proposed E-V solver renders a useful tool for addressing multidomain simulation. © 1982-2012 IEEE.

Iii-V Bismide Optoelectronic Devices, Dongsheng Fan

Graduate Theses and Dissertations

This dissertation explores modeling, molecular beam epitaxy growth, and fabrication of III-V bismide optoelectronic devices, which are of great importance in modern applications of telecommunication, gas sensing, environment monitoring, etc. In the current room-temperature continuous-wave operational GaSb-based type-I InGaAsSb/AlGaInAsSb quantum well laser diodes in 3-4 um mid-wavelength range, the lasing wavelength and performance of the devices are limited due to the lack of hole confinement in the active regions. In this dissertation, a novel GaSb-based GaInAsSbBi material is proposed to replace the conventional InGaAsSb material in the quantum well region, which enables the laser diodes achieve up to 4 µm …

Tower Of Babel: A Crowdsourcing Game Building Sentiment Lexicons For Resource-Scarce Languages, Yoonsung Hong, Haewoon Kwak, Youngmin Baek, Sue. Moon

Research Collection School Of Computing and Information Systems

With the growing amount of textual data produced by online social media today, the demands for sentiment analysis are also rapidly increasing; and, this is true for worldwide. However, non-English languages often lack sentiment lexicons, a core resource in performing sentiment analysis. Our solution, Tower of Babel (ToB), is a language-independent sentiment-lexicon-generating crowdsourcing game. We conducted an experiment with 135 participants to explore the difference between our solution and a conventional manual annotation method. We evaluated ToB in terms of effectiveness, efficiency, and satisfactions. Based on the result of the evaluation, we conclude that sentiment classification via ToB is accurate, …

Efficient Extraction Of Json Information In Sas Using The Scanover Function, Murphy Choy, Kyong Jin Shim

Research Collection School Of Computing and Information Systems

JSON, otherwise known as JavaScript Object Notation, is a popular data interchange format which provides a humanreadable format. It is language independent and can be read easily in a variety of computer languages. With the riseof Twitter and other unstructured data, there has been a move to incorporate such data as a way of disseminatinginformation. Twitter currently provides a simple API for users to extract tweets using JSON format. While SAS doesnot currently have a direct way of reading JSON, the SCANOVER function in SAS data step provides user with asimple and effective approach to getting JSON information into SAS …

Tesla: An Energy-Saving Agent That Leverages Schedule Flexibility, Jun Young Kwak, Pradeep Varakantham, Rajiv Maheswaran, Burcin Becerik-Gerber, Milind Tambe

Research Collection School Of Computing and Information Systems

This innovative application paper presents TESLA, an agent-based application for optimizing the energy use in commercial buildings. TESLA’s key insight is that adding flexibility to event/meeting schedules can lead to significant energy savings. TESLA provides three key contributions: (i) three online scheduling algorithms that consider flexibility of people’s preferences for energyefficient scheduling of incrementally/dynamically arriving meetings and events; (ii) an algorithm to effectively identify key meetings that lead to significant energy savings by adjusting their flexibility; and (iii) surveys of real users that indicate that TESLA’s assumptions exist in practice. TESLA was evaluated on data of over 110,000 meetings held …

Anonymous Authentication Of Visitors For Mobile Crowd Sensing At Amusement Parks, Divyan Konidala, Robert H. Deng, Yingjiu Li, Hoong Chuin Lau, Stephen Fienberg

Research Collection School Of Computing and Information Systems

In this paper we focus on authentication and privacy aspects of an application scenario that utilizes mobile crowd sensing for the benefit of amusement park operators and their visitors. The scenario involves a mobile app that gathers visitors’ demographic details, preferences, and current location coordinates, and sends them to the park’s sever for various analyses. These analyses assist the park operators to efficiently deploy their resources, estimate waiting times and queue lengths, and understand the behavior of individual visitors and groups. The app server also offers visitors optimal recommendations on routes and attractions for an improved dynamic experience and minimized …

Master Physician Scheduling Problem, Aldy Gunawan, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

We study a real-world problem arising from the operations of a hospital service provider, which we term the master physician scheduling problem. It is a planning problem of assigning physicians’ full range of day-to-day duties (including surgery, clinics, scopes, calls, administration) to the defined time slots/shifts over a time horizon, incorporating a large number of constraints and complex physician preferences. The goals are to satisfy as many physicians’ preferences and duty requirements as possible while ensuring optimum usage of available resources. We propose mathematical programming models that represent different variants of this problem. The models were tested on a real …

Energy-Neutral Scheduling And Forwarding In Environmentally-Powered Wireless Sensor Networks, Alvin Cerdena Valera, Weng Seng Soh, Hwee-Pink Tan

Research Collection School Of Computing and Information Systems

In environmentally-powered wireless sensor networks (EPWSNs), low latency wakeup scheduling and packet forwarding is challenging due to dynamic duty cycling, posing time-varying sleep latencies and necessitating the use of dynamic wakeup schedules. We show that the variance of the intervals between receiving wakeup slots affects the expected sleep latency: when the variance of the intervals is low (high), the expected latency is low (high). We therefore propose a novel scheduling scheme that uses the bit-reversal permutation sequence (BRPS) – a finite integer sequence that positions receiving wakeup slots as evenly as possible to reduce the expected sleep latency. At the …

Reliability Analysis Of Social Networks, Kellie R. Schneider

Graduate Theses and Dissertations

The primary focus of this dissertation is on the quantification of actor interaction and the dissemination of information through Social networks. Social networks have long been used to model the interactions between people in various Social and professional contexts. These networks allow for the explicit modeling of the complex interrelations between relevant individuals within an organization and the role they play in the decision making process. This dissertation considers Social networks represented as network flow models in which actors have the ability to provide some level of influence over other actors within the network. The models developed incorporate performance metrics …