Digital Commons Network^™

Cfd Based Design And Modelling Of Wind Fence To Mitigate High-Speed Wind Loading On A Modular Data Center, Devi Prasad Gorrepati

Mechanical and Aerospace Engineering Theses - Archive

A Modular Data Center (MDC) is a portable method of deploying a data center’s capacity. As an alternative to the traditional data center, an MDC can be placed anywhere data capacity is required. But this comes at the cost of making the MDC operable at any desired location with the environmental factors such as earthquakes and heavy winds. This study focuses on mitigating high-speed wind loading on the MDCs by designing a wind fence to reduce wind speed. Although wind fences are used in many agricultural and farming practices, their usage pertaining to MDCs is very limited. The challenge is …

Enhancement Of Fog-Collection Efficiency Of A Raschel Mesh Using Surface Coatings And Geometric Changes, Mithun Rajaram

Mechanical and Aerospace Engineering Theses - Archive

In a few countries, such as Chile, a Raschel mesh is widely used in the field to collect fog. In this work, we explored the possibility of enhancing fog-collection efficiency of a typical Raschel mesh through surface modification and geometric changes. We demonstrated about 100% enhancement in the fog-collection efficiency.

Tbi Induced Rate Dependent Viscoelastic Response Of Axon: Predictions From A Mathematical Model, Manikanta Jonnalagadda

Mechanical and Aerospace Engineering Theses - Archive

Traumatic brain injury (TBI) accounts to almost one fifth of total fatal injuries. Even though there are various mechanisms hypothesized for the causes leading to TBI, diffuse axonal injury (DAI) is found to be the most observed criterion. The reason for axonal failure in DAI has been studied extensively using experimental and computational models. It was found that axons behave like viscoelastic materials, thus exhibiting rate dependent behavior under loading. This viscoelastic behavior of axons is believed to drive the failure of axons and its substructures. It was observed that axon failure is caused by failures and distortions in axonal …

Board Level Flexural Reliability Testing And Failure Analysis Of Printed Circuit Boards With Wcsp Packages, Guruprasad Shrikant Shinde

Mechanical and Aerospace Engineering Theses - Archive

Printed circuit boards, widely known as PCBs; are the skeleton behind every technology today. Electronics have integrated with every other engineering domain to improve the outcomes. It is very important that they remain intact in slightly extreme physical conditions. They are used in wide range applications which may lead to mechanical stress-strain in some conditions. There are various boards with different kinds of packages on them. A 0.7mm thick board with WCSP; Wafer chip scale package is a prime specimen for my work. The research includes designing exact replica of given PCB into ANSYS and its reliability testing. A 3-point …

Interface Reaction Induced Stress Development In An Aluminum Thin Film Copper Bulk Plate Diffusion Couple, Michael Codie Mishler

Material Science and Engineering Theses - Archive

This thesis investigates the mechanism of the interface reaction induced intermetallic phase formation (IMC) and its impact on the interface reliability in Al-Cu diffusion couple pairing. This study is motivated by the accelerated failure experiments in lead frame to integrated circuit (IC) package wire-bonds using copper (Cu) wire and aluminum (Al) bond-pad that have shown failure most often occurs at the interface of the intermetallic compound (IMC) γ2-phase (Cu9Al4). In order for simulative investigation, we created a diffusion couple consisting of Cu bulk plate coated pure Al thin films with thickness of ~2µm. This configuration is adapted to resemble the …

Improving Water Quality Forecasting Using Data Assimilation, Hamideh Riazi

Civil Engineering Dissertations - Archive

Population growth increases agricultural, industrial and human activities which threaten the quality of water resources, especially water supply sources such as lakes and reservoirs. In potentially high-impact situations such as algal blooms, active measures such as controlled release from reservoirs may be necessary. To minimize release while meeting the water quality requirements, accurate short-range water quality forecast is necessary. Because watershed water quality models have a large number of state variables most of which are never observed, their initial conditions (IC) are subject to large uncertainties which may propagate into large forecast errors. In this research, a data assimilation (DA) …

Estimation Of Rebar Corrosion In Concrete Using Ground Penetrating Radar, Rakesh Krishnarajapete Raju

Civil Engineering Theses - Archive

The purpose of this research was to quantitatively relate the amount of rebar corrosion in concrete with the amplitude of electromagnetic waves generated from Ground penetrating radar (GPR). Many studies have been undertaken on qualitative measurement of corrosion, but there are very few studies regarding estimation of rebar corrosion quantitatively. This experiment involved the use of accelerated corrosion by impressed current technique to corrode the rebar inside the concrete and GPR to determine the extent of corrosion, while making a comparison with a stainless steel bar which was used as a cathode to create a galvanic cell action. Rebars were …

Improving The Rainfall And Flood Frequency Analyses Using Stochastic Storm Transposition Method, Morteza Kiani

Civil Engineering Theses - Archive

Reproduction and realization of historical rainfall events provides foundations for flood and rainfall frequency analyses and the advancement of meteorological studies. Stochastic storm transposition (SST) is a method for such a purpose and enables us to perform frequency analyses by transposing observed historical storm events over any given watershed. The goal of this study is to stochastically examine the impacts of extreme events on all locations in a homogeneity zone. Storms with the same probability of occurrence on a defined homogenous neighborhood will generate various impacts due to spatial and temporal variations of the storms. Transposing storms occurring in the …

Characterization Of The Constituent Mineral Components Of North African Surface Dust Samples Utilizing Computer Controlled Scanning Electron Microscopy (Ccsem), Zakariah Edward Sabatka

Earth & Environmental Sciences Theses - Archive

Analysis of the constituent mineral components of surface dusts/soils from Chad-Niger region, North Africa, was undertaken by computer controlled scanning electron microscopy (CCSEM) to determine if differences in composition could be used for source attribution to distinguish windblown material from different contributing source areas. A total of 11 surficial samples were selected for analysis by computer controlled scanning electron microscopy (CCSEM). These samples were from two different geographic locations in the Chad-Niger region. CCSEM analysis generates data on individual dust particles that includes: particle size, shape, and chemical composition. This type of particle characterization used a Scanning Electron Microscope (SEM) …

Nebraska's Public Access Hunting Program: Hunter Preferences And Usage Final Report, Lisa Pennisi, Mark E. Burbach, Namyun Kil, Muhammed Imran Kahn, Andrew J. Tyre

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Real Time Analytics On Digital Distraction, Kristian Welch

Computer Science and Software Engineering

Hypothesis: empirically measuring the users productivity has the potential to significantly increase their productivity. This paper is the documentation of the process of building software capable of verifying this hypothesis. Starting with the research which gives enough evidence to warrant the hypothesis, also included is commentary on the prototyping, design decisions, and iteration based on user feedback of the software.

A Quay Crane System That Self-Recovers From Random Shocks, Yun Fong Lim, Yan Zhang, Chen Wang

Research Collection Lee Kong Chian School Of Business

The main challenge for a container terminal is to maximize its throughput using limited resources subject to various operational constraints under uncertainty. Traditional methods try to achieve this through an optimized plan by solving a quay crane scheduling problem; but the plan may become obsolete or infeasible after shocks (changes in the system due to uncertainty). To respond to shocks these methods require frequent re-planning, which increases the operations cost. We propose a new method to counter this. Instead of creating plans, we develop an operating protocol to respond to shocks without re-planning. Under this protocol, each quay crane along …

Supply Management In Multiproduct Firms With Fixed Proportions Technology, Onur Boyabatli

Research Collection Lee Kong Chian School Of Business

This paper studies the supply management of a primary input, where this input gives rise to multiple products in fixed proportions. My objective is twofold. First, I study fixed proportions technology under demand uncertainty in comparison with flexible and the dedicated technologies. I show that fixed proportions technology has a cost- pooling value over dedicated technology, which is larger than the capacity-pooling value of flexible technology over dedicated technology. I identify the critical role that demand correlation plays with the fixed proportions technology: In contrast to the capacitypooling value which decreases in demand correlation, the cost-pooling value increases in demand …

Gas Dynamics In Tidal Dwarf Galaxies: Disc Formation At Z = 0, Federico Lelli, Stacy Mcgaugh

Faculty Scholarship

Tidal dwarf galaxies (TDGs) are recycled objects that form within the collisional debris of interacting and merging galaxies. They are expected to be devoid of non-baryonic dark matter, since they can only form from dissipative material ejected from the discs of the progenitor galaxies. We investigate the gas dynamics in a sample of six bona fide TDGs around three interacting and post-interacting systems: NGC 4694, NGC 5291, and NGC 7252 ("Atoms for Peace"). For NGC 4694 and NGC 5291, we analyse existing HI data from the Very Large Array (VLA),while for NGC 7252 we present new HI observations from the …

Investigations Into The Cross-Infectivity Of Nematode Parasites Of Cattle And Sheep, Eva Marie Wray

Graduate Theses and Dissertations

The existence of anthelmintic resistance is not singular in parasite species, host species or geographic region. It has become a problem of worldly stature, especially when considering sheep nematodes. Recommendations have been modified from chemical-based control to multipart, managerial intervention. Compared with nematodes of cattle, the worldwide resistance of sheep nematodes to anthelmintic remedies is much more pronounced and urgent. As the resistance to essentially all anthelmintic classes approaches a cautionary level, the implementation of non-chemical controls has grown increasingly essential. Six-6 to 8 month old Holstein steer calves, six-5 month old Katahdin ram lambs and eight-5 month old Suffolk …

Deposition And Characterization Of Carbon Nanotubes (Cnts) Based Films For Sensing Applications, Amila C. Dissanayake

Dissertations

The advent of carbon nanotubes (CNTs) has opened up lot of novel applications because of their unique electrical and mechanical properties. CNTs are well known material for its exceptional electrical, mechanical, optical, thermal and chemical properties. A single-wall nanotube (SWNT) can be either semiconducting, metallic or semi-metallic, based on its chirality and diameter. SWNTs can be used in transistor device as active channels due to high electron mobility (~10000 cm2/(V s), electrical interconnects, nano-scale circuits, field-emission displays, light-emitting devices and thermal heat sinks due to low resistivity, high current density (~109A cm-2) and high thermal conductivity (~3500 W m-1). Further, …

Deep Fluid Inputs Into The Continental-Scale Nubian Sandstone Aquifer System Constrained By Hydrochemical, Stable Isotope, And Noble Gas Data, Abdel Mawgoud Mohammed

Dissertations

The Nubian Sandstone Aquifer System (NSAS) of northeastern Africa is one of the largest confined fossil-water aquifer systems in the world, with several nations relying on it (Egypt, Libya, Sudan and Chad). This groundwater is the biggest and in some cases the only future source of water to meet the development goals of each NSAS country. This study provides new geochemical data from the main oases of the Western Desert of Egypt and a compilation of published hydrochemical data from the regional aquifer. Interpretation of results suggests heterogeneous fluid mixing within the aquifer, the potential for hydrochemical sub-basins, and a …

Adaptive Scaling Of Cluster Boundaries For Large-Scale Social Media Data Clustering, Lei Meng, Ah-Hwee Tan, Donald C. Wunsch

Research Collection School Of Computing and Information Systems

The large scale and complex nature of social media data raises the need to scale clustering techniques to big data and make them capable of automatically identifying data clusters with few empirical settings. In this paper, we present our investigation and three algorithms based on the fuzzy adaptive resonance theory (Fuzzy ART) that have linear computational complexity, use a single parameter, i.e., the vigilance parameter to identify data clusters, and are robust to modest parameter settings. The contribution of this paper lies in two aspects. First, we theoretically demonstrate how complement coding, commonly known as a normalization method, changes the …

Coordinated Persuasion With Dynamic Group Formation For Collaborative Elderly Care, Budhitama Subagdja, Ah-Hwee Tan

Research Collection School Of Computing and Information Systems

Ageing in place demands a new paradigm of inhouse caregiving allowing many aspects of daily lives to be tackled by smart appliances and technologies. The important challenges include the effective provision of recommendations by multiple parties of caregiver constituting changes of the user’s behavior. In this multiagent environment, interdependencies between agents become major issues to tackle. This paper presents an approach of dynamic group formation for autonomous caregiving agents to collaborate in recommending different aspects of well-being. The approach supports the agents to regulate the timing of their recommendations, prevent conflicting messages, and cooperate to make more effective persuasions. A …

Co-Rotational Finite Element Solid Simulation With Collisions, Patrick Riordan

Computer Science and Software Engineering

This paper is a tutorial on how to implement a deformable solid simulation with collisions based off of Matthias Mueller's Real Time Physics Course Notes. It covers the topics continuum mechanics, finite element analysis, implicit Euler integration, and handling collision.

Spatial Analysis Of Distributions And Habitat Conditions Of Fallopia Japonica (Japanese Knotweed) Invasive Species Applying Unmanned Helicopter Remote Sensing, Jiazhen Zhang

Great Lakes Center Masters Theses

Abstract:

Fallopia japonica (Japanese knotweed) is a perennial herbaceous plant that is native to East Asia. It is considered as one of the worst invasive species worldwide because of its serious impact on biological diversity and human activities (Lowe et al., 2001). Once established, Japanese knotweed forms dense stands that shade and crowd out native plant species. The objectives of this research were to verify and confirm the distribution of Japanese knotweed as published online by the New York Department of Environmental Conservation (DEC) – iMap and to identify the geographic areas of spreading and the local habitat conditions. In …

Mycorrhizal Roots In A Temperate Forest Take Up Organic Nitrogen From 13c- And 15n-Labeled Organic Matter, Matthew A. Vadeboncoeur, Andrew P. Ouimette, Erik A. Hobbie

All Materials

Background and Aims

The importance of the uptake of nitrogen in organic form by plants and mycorrhizal fungi has been demonstrated in various ecosystems including temperate forests. However, in previous experiments, isotopically labeled amino acids were often added to soils in concentrations that may be higher than those normally available to roots and mycorrhizal hyphae in situ, and these high concentrations could contribute to exaggerated uptake.

Methods

We used an experimental approach in which we added ¹³C-labeled and ¹⁵N-labeled whole cells to root-ingrowth cores, allowing proteolytic enzymes to release labeled organic nitrogen at a natural rate, as …

Diversity In American Graduate Education Admissions: Twenty-First-Century Challenges And Opportunities, Donald Mitchell Jr., Ph.D., Elizabeth A. Daniele

Executives, Administrators, & Staff Publications

While the legal precedent of affirmative action in U.S. higher education is well documented, graduate admissions practices that withstand strict scrutiny need further documentation. This chapter fills that gap in three ways. First, we briefly highlight the history of affirmative action in U.S. higher education as it relates to broadening the participation of URMs. Second, we offer best practices in U.S. graduate admissions that take into account the benefits of diversity while working within legal guidelines. We then close with considerations for future scholarship, policies, and practices.

Modeling Information Reliability And Maintenance: A Systematic Literature Review, Daysi A. Guerra Garcia

Industrial Engineering Undergraduate Honors Theses

Operating a business efficiently depends on effective everyday decision-making. In turn, those decisions are influenced by the quality of data used in the decision-making process, and maintaining good data quality becomes more challenging as a business expands. Protecting the quality of the data and the information it generates is a challenge faced by many companies across all industrial sectors. As companies begin to use data from these large data bases they will need to begin to develop strategies for maintaining and assessing the reliability of the information they generate using this data. A considerable amount of literature exists on data …

The Application Of Trajectory Analysis For An Early Warning System In Stem Courses, Un Jung Lee

Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions)

The retention of STEM (science, technology, engineering, and mathematics) majors has become a national concern. “Early warning systems†(EWS) are being developed to identify students who perform poorly early in the semester so that interventions can be implemented. The research reported here utilizes clicker scores and review quiz scores collected in every class session for the longitudinal analysis, as well as pre-course concept inventory scores and self-reported student characteristics. Pre course concept inventory scores were significantly predictive of final course grade. Student demographic characteristics had a smaller fraction of final course grade explained. The cumulative average student clicker score was …

An Ensemble Three-Dimensional Constrained Variational Analysis Method To Derive Large-Scale Forcing Data For Single-Column Models, Shuaiqi Tang

Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions)

Atmospheric vertical velocities and advective tendencies are essential as large-scale forcing data to drive single-column models (SCM), cloud-resolving models (CRM) and large-eddy simulations (LES). They cannot be directly measured or easily calculated with great accuracy from field measurements. In the Atmospheric Radiation Measurement (ARM) program, a constrained variational algorithm (1DCVA) has been used to derive large-scale forcing data over a sounding network domain with the aid of flux measurements at the surface and top of the atmosphere (TOA). We extend the 1DCVA algorithm into three dimensions (3DCVA) along with other improvements to calculate gridded large-scale forcing data. We also introduce …

Multi-Marker Linkage Disequilibrium Mapping Of Quantitative Trait Loci, Soyoun Lee

Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions)

Background: Genome-wide associations have been studied for years to infer relationships between biological traits and their underlying genetic causes, known as quantitative traits loci (QTL), in a process known as QTL mapping. Single nucleotide polymorphisms (SNPs), which are commonly used genetic markers, are usually in linkage disequilibrium (LD) with each other within a small genetic region. Both single- and double-marker-based LD mapping methods have been developed by taking advantage of LD structure. Method: In this thesis, a more general LD mapping framework with an arbitrary number of markers has been developed in order to improve LD mapping and its detection …

A Dynamic Oyster Reef Bioenergetics Model: Predictions Of Secondary Production Based On Different Restoration Scenarios, Elizabeth Gomez

Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions)

The presence of oyster reefs augments the biomass and abundance of many transient fish and crustacean species. Therefore, restoration of oyster reefs has become an increasingly common practice in coastal areas with the goal of enhancing production of transient fish. However, predicting the effect of oyster restoration on transient fish community biomass remains elusive. To address this challenge, I created a trophic bioenergetic model to understand how energy transfers in an oyster reef and assess the effects of various restoration strategies on transient fish species. The model used a set of functional groups representing organisms commonly found in an oyster …

The Application Of Trajectory Analysis For An Early Warning System In Stem Courses, Un Jung Lee

Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions)

The retention of STEM (science, technology, engineering, and mathematics) majors has become a national concern. “Early warning systems†(EWS) are being developed to identify students who perform poorly early in the semester so that interventions can be implemented. The research reported here utilizes clicker scores and review quiz scores collected in every class session for the longitudinal analysis, as well as pre-course concept inventory scores and self-reported student characteristics. Pre course concept inventory scores were significantly predictive of final course grade. Student demographic characteristics had a smaller fraction of final course grade explained. The cumulative average student clicker score was …

An Ensemble Three-Dimensional Constrained Variational Analysis Method To Derive Large-Scale Forcing Data For Single-Column Models, Shuaiqi Tang

Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions)

Atmospheric vertical velocities and advective tendencies are essential as large-scale forcing data to drive single-column models (SCM), cloud-resolving models (CRM) and large-eddy simulations (LES). They cannot be directly measured or easily calculated with great accuracy from field measurements. In the Atmospheric Radiation Measurement (ARM) program, a constrained variational algorithm (1DCVA) has been used to derive large-scale forcing data over a sounding network domain with the aid of flux measurements at the surface and top of the atmosphere (TOA). We extend the 1DCVA algorithm into three dimensions (3DCVA) along with other improvements to calculate gridded large-scale forcing data. We also introduce …