Digital Commons Network^™

Using An Ontology To Improve The Web Search Experience, Tian Tian

Dissertations

The search terms that a user passes to a search engine are often ambiguous, referring to homonyms. The results in these cases are a mixture of links to documents that contain different meanings of the search terms. Current search engines provide suggested query completions in a dropdown list. However, such lists are not well organized, mixing completions for different meanings. In addition, the suggested search phrases are not discriminating enough. Moreover, current search engines often return an unexpected number of results. Zero hits are naturally undesirable, while too many hits are likely to be overwhelming and of low precision.

This …

Consequences Of Stochastic Mrna Synthesis In A Gene Regulatory Pathway, Khyati Shah

Dissertations

Gene expression is a stochastic process, with elements of randomness present in both transcription and translation. This stochasticity results in cell-to-cell variation in the amounts of gene products, mRNAs and proteins, and is observed in organisms ranging from bacteria and yeast to higher eukaryotes. Randomness in the activation and inactivation of a gene is the preliminary cause of this variation. At the level of proteins, these variations are buffered compared to levels of mRNA, due to the longer lifespan of proteins. Nevertheless, there is substantial variation observed at the level of proteins, resulting in phenotypic diversity among genetically identical cells. …

Terahertz Wireless Communication, Ke Su

Dissertations

The goal of this thesis is to explore Terahertz (THz) wireless communication technology. More specifically the objective is to develop and characterize several THz communication systems and study the effect of atmosphere propagation through fog droplets and dust particles on THz communications.

For demonstration, a THz continuous wave (CW) photomixing system is designed. Terahertz signals are phase encoded with both analog ramp signals and pseudorandom binary data, transmitted over a short distance, and detected. The limitation of transmission bandwidth, low single to noise ratio, vibration effects are also analyzed. In order to study and compare propagation features of THz links …

Analysis Of A Composite Dielectric-Ferrite Loaded Resonator Using The Transmission Line Model With Application To A Tunable Dual Mode Bandpass Filter, Charlotte Blair

Dissertations

A magnetically tuned filter is presented in this dissertation. Filter tuning of a dielectric ceramic resonator is accomplished using by using two oppositely biased ferrites. Specifically, a change in the applied magnetic field is used to alter the permeability of the ferrite so as to achieve maximum tuning range. Through electromagnetic (EM) simulations and laboratory experiments, tuning of the filter passband by 20 MHz is demonstrated.

This investigation focuses on the design of a bandpass resonator using a combination of dielectric-ferrite material layers. An initial simplification of the geometry of the structure is used as the basis for a program …

Design And Implementation Of A Cyberinfrastructure For Rna Motif Search, Prediction And Analysis, Dongrong Wen

Dissertations

RNA secondary and tertiary structure motifs play important roles in cells. However, very few web servers are available for RNA motif search and prediction. In this dissertation, a cyberinfrastructure, named RNAcyber, capable of performing RNA motif search and prediction, is proposed, designed and implemented.

The first component of RNAcyber is a web-based search engine, named RmotifDB. This web-based tool integrates an RNA secondary structure comparison algorithm with the secondary structure motifs stored in the Rfam database. With a user-friendly interface, RmotifDB provides the ability to search for ncRNA structure motifs in both structural and sequential ways. The second component of …

Trust Management Schemes For Peer-To-Peer Networks, Lin Cai

Dissertations

Peer-to-peer (P2P) networking enables users with similar interests to exchange, or obtain files. This network model has been proven popular to exchange music, pictures, or software applications. These files are saved, and most likely executed, at the downloading host. At the expense of this mechanism, worms, viruses, and malware find an open front door to the downloading host and gives them a convenient environment for successful proliferation throughout the network. Although virus detection software is currently available, this countermeasure works in a reactive fashion, and in most times, in an isolated manner. A trust management scheme is considered to contain …

Hot-Melt Mixing Of Partially Miscible Active Pharmaceutical Ingredient-Polymer Mixtures, Min Yang

Dissertations

Solid dispersion/solution processes for producing pharmaceutical oral dosages such as hot-met extrusion (HME) have received increasing attention by industry and academe because they can enhance drugs’ solubility and even bioavailability to a great extent by converting drugs from crystalline to amorphous form. HME can be carried out at two process temperature regimes: one where T_process > T_m of the drug and the T_g of the polymer (or the T_m for the case of semi-crystalline polymers); the other at T_m > T_process > T_g (T_m for the case of semi-crystalline polymer). Processing below the drug’s …

Micromechanical Study Of Two-Phase Flow During Air Sparging, Shengyan Gao

Dissertations

Air sparging (AS) is an in-situ soil/groundwater remediation technology, which involves the injection of pressurized air/oxygen through an air sparging well below the region of contamination. The efficiency of the in-situ sparging system is mainly controlled by the extent of contact between injected air and contaminated soil and pore fluid. Hence, characterizing the mechanisms governing movement of air through saturated porous media is therefore critical to the design of an effective cleanup treatment. However, in spite of the success of air sparging as a remediation technique for the clean-up of contaminated soils, to date, the fundamental mechanisms or the physics …

Development Of X-Ray Holography Methods For Structure Determination : Application Of High Speed Detectors And Novel Numerical Methods, Yuhao Wang

Dissertations

Holographic methods show much promise to enable direct determination of atomic structure with minimal assumptions and approximations. The approach can, in principle, provide three dimensional information on atomic positions. However, significant developments in experimental techniques, instrumentation and in data collection and analysis are needed. A review of the holography method is given with a focus on X-ray fluorescence holography. Methods for analysis of X-ray holographic data are also reviewed. An overview of the detectors relevant to X-ray measurements is also presented. An experimental apparatus for rapid acquisition of X-ray holographs using novel X-ray detectors has been developed. The integration of …

Distributed Spectrum Leasing Via Cooperation, Tariq Elkourdi

Dissertations

“Cognitive radio” networks enable the coexistence of primary (licensed) and secondary (unlicensed) terminals. Conventional frameworks, namely commons and property-rights models, while being promising in certain aspects, appear to have significant drawbacks for implementation of large-scale distributed cognitive radio networks, due to the technological and theoretical limits on the ability of secondary activity to perform effective spectrum sensing and on the stringent constraints on protocols and architectures.

To address the problems highlighted above, the framework of distributed spectrum leasing via cross-layer cooperation (DiSC) has been recently proposed as a basic mechanism to guide the design of decentralized cognitive radio networks. According …

Approximate String Matching Methods For Duplicate Detection And Clustering Tasks, Oleksandr Rudniy

Dissertations

Approximate string matching methods are utilized by a vast number of duplicate detection and clustering applications in various knowledge domains. The application area is expected to grow due to the recent significant increase in the amount of digital data and knowledge sources. Despite the large number of existing string similarity metrics, there is a need for more precise approximate string matching methods to improve the efficiency of computer-driven data processing, thus decreasing labor-intensive human involvement.

This work introduces a family of novel string similarity methods, which outperform a number of effective well-known and widely used string similarity functions. The new …

Superarmed Glycosyl Donors In Chemical Glycosylation, Hemali Deepthika Premathilake

Dissertations

Only recently has the tremendous biological significance and therapeutic potential of carbohydrates and conjugates thereof (glycoproteins, glycolipids, proteoglycans, etc.) begun to emerge. As the appreciation for the biological roles of carbohydrates a growing demand for efficient and scalable methods towards the synthesis of these challenging molecules has become even more imperative. This has led to the development of a variety of expeditious strategies for oligosaccharide assembly. Amongst these strategies, the so-called armed-disarmed strategy introduced by Fraser-Reid is of particular attractiveness as it allows for chemoselective oligosaccharide synthesis. Recently, the conformational changes as well as the strategic placement of common protecting …

Family Structure And Risk Factors: An Investigation Into Emotional And Behavioural Outcomes For Nine-Year-Olds., Zara Lafferty

Dissertations

This study examined the relationship between family structure and risk factors for children’s emotional and behavioural outcomes at 9 years of age. Family structure in this study is defined as; married, separated, divorced, widowed and never married families. Three risk factors were identified from the literature; economic deprivation, maternal depression and life events. This study is a cross sectional quantitative analysis of the ‘Growing Up in Ireland’s’ child cohort (9 year olds) dataset. This is nationally representative sample of 9 year old children living in Ireland; the sample was collected through a two-stage, stratified random sampling approach. Of the 8,568 …

Biochar From Agricultural Byproducts For Improved Soil Quality And Carbon Sequestration, Djaafar Rehrah

Dissertations

Soil carbon sequestration has emerged as an innovative approach that may offer a low-risk and an efficient way to mitigate climate change and replenish soil fertility. In various agricultural production systems, byproducts are produced in significant amounts from crop residues such as pecan shells (PC), peanut shells (PS), and cotton gin (CG) that can be used to produce biochar and applied to agricultural soil first to sequester C and second to enhance plant growth by supplying and retaining nutrients, improving soil physical and biological properties. The objectives of this study were to (a) produce biochars from different byproducts (PC, PS, …

An Examination Of The Practitioners' Role In Promoting Compliance With Participants In The Irish Drug Treatment Court, James N. O'Sullivan

Dissertations

The study examines the Irish Drug Treatment Court (IDTC) programme and specifically its practitioners‟ role in promoting offender compliance, which is essential to the success of community supervision and community punishment programmes. Existing literature and research was studied extensively, paying particular attention to compliance and legitimacy theory as well as the challenges of addiction and offending in the overall equation of compliance. Qualitative research methods were utilised with non-participatory observation of IDTC team meetings and court sittings, and semi-structured interviews with practitioners. Five IDTC professionals were interviewed and their experience, skills, education and opinion contributed extensively to the study‟s aims …

Hear3d: A Study Of Spatial Sounds Effect On Language Learning, Brendan Cregan

Dissertations

Spatial sound is the manipulation of audio to add the illusion of position to the source of the sound, i.e. making sounds seem to originate from behind you or from different points around a room. Headphones must be used to achieve the optimum level of 3D sound. At any time over half a billion people are learning languages with the aide of audio which is why and the study of the effect or potential effects that the spatial sounds have on language learning is particularly interesting. If the application of spatial sounds to educational audio clips could be shown to …

Sports Data Mining Technology Used In Basketball Outcome Prediction, Chenjie Cao

Dissertations

Driven by the increasing comprehensive data in sports datasets and data mining technique successfully used in different area, sports data mining technique emerges and enables us to find hidden knowledge to impact the sport industry. In many instances, predicting the outcomes of sporting events has always been a challenging and attractive work and is therefore drawing a wide concern to conduct research in this field. This project focuses on using machine learning algorithms to build a model for predicting the NBA game outcomes and the algorithms involve Simple Logistics Classifier, Artificial Neural Networks, SVM and Naïve Bayes. In order to …

Accessible Information: Advocating The Use Of Technology For Individuals With Intellectual Disability On Their Path To Individualised Services, Michelle Moloney

Dissertations

Providing people with an intellectual disability (ID), opportunities for social integration have been shown to have a reliable positive influence on their well-being (Wehmeyer et al., 2006; Bunning, 2009). A large percentage of individuals with ID are unable to read and write. For this reason in order for the person to make an informed choice the person needs to have good information presented in a way that they can understand. They may need to see tangible visual aids (video, role play, film, photographs). It may need to be demonstrated to them a number of times. This assists a person in …

The Prevailing Obstacles In Web Accessibility On Three Well-Known Websites For Older People With Sight Difficulties, Sarah O'Reilly

Dissertations

Prior research has argued that there is no one best approach to evaluating web accessibility and proposes the adoption of multiple approaches. Following these proposals this research used three different approaches for evaluating accessibility on websites for accessibility to older persons with sight difficulties as there are advantages and disadvantages to each approach. Approached used included: (1) Using automated tools to determine accessibility, which looks at the code of websites to get a general overview of accessibility issues. (2) Manually looking at the design, code and also how it might impact the user. This involved a manual assessment of each …

Investigating Staff Morale In An Elementary School Setting, Bethany Pendino

Dissertations

The way that employees feel about their workplaces and their jobs has implications not only for each individual but for the success of the workplace as well. In a school setting, investigating how teachers and other staff members feel about their jobs and their workplace and then seeking to improve employee morale may benefit schools. This action research investigated staff morale at Sparkling Springs Elementary School. The investigation examined how efforts to improve staff morale influenced staff members, students, and parents. Through staff surveys and focus groups, the researcher obtained information on staff members‟ feelings and attitudes related to the …

Analytical Strategies For Drug Residues In Various Matrices In A Regulatory Laboratory., Geraldine Dowling

Dissertations

Abstract

Today, in modern farming practices veterinary drugs are given to food-producing animals. The generic term “veterinary drugs” covers a broad variety of classes of chemical compounds and the list of drugs is enormous and it is a significant analytical challenge in regulatory control to provide monitoring programmes. The major concerns in veterinary drug usage are the presence of harmful residues that may be introduced into the human food chain. The aim of this research is the development of analytical methods capable of screening and confirming increased numbers of these residues in target matrices by Gas Chromatography Tandem Mass Spectrometry …

An Exploration Of Stepfamily Experiences Of Young People In Ireland., Audrey Mcgee

Dissertations

This qualitative research study conducted semi-structured interviews to explore the stepfamily experiences of ten individuals, aged eighteen to twenty four years. The findings indicated that the stepfamily brought challenges and a range of benefits to the participants’ life experiences. The key difficulties pertained to issues regarding conflict, lack of communication and complex challenges. The cited benefits of stepfamily experiences included improved financial resources, an additional parental figure, a sense of stability, opportunities for personal growth and the gaining of additional siblings. One significant finding of the study was the positive enduring bonds that some individuals made with stepparents and stepsiblings. …

Rate-Based Robust Adaptive Performance Tracking Control Of Network Flows, Xiaoyan Mei

Dissertations

Network flow control methods have been studied for years to ensure the efficient usage of network resources. By adopting a representation reminiscent of the sliding surface representation, this work explores a highly adaptive network flow control strategy. The rate-based network flow control scheme is investigated through a novel model description in the matrix notation, and guaranteed to be stable under mild assumptions. The control law has a simple form but the proof of robust stability is quite involved via the Lyapunov theory. Simulations demonstrated that the developed adaptive algorithms are robust and effective in maintaining good link price and backlog …

The Effects Of A Videoconferencing Implementation Project On Educators' Level Of Concern In Southwest Michigan Schools, Dennis David Lundgren

Dissertations

Problem. Two-way, interactive videoconferencing is emerging as an important technology tool for K-12 educators. The challenge is to identify and describe successful implementation. Educator concerns related to implementation may inhibit success. The focus of this study of a federally funded videoconferencing project is to address the factors that influence educators' level of concern.

Method. The Concerns-Based Adoption Model (CBAM) Stages of Concern (SoC) instrument was administered to measure the level of concern of two cohorts of participants. Data related to project, including number of connections, district and building technical support, professional development, and equipment reliability were also collected. One-way …

Image Slavery And Mass Media Pollution: Examining The Sociopolitical Context Of Beauty And Self Image In The Lives Of Black Women, Jennifer Richardson

Dissertations

The ways in which African American women negotiate the intersections of popular media, dominant discourses of beauty, and identity are rarely explored. This work brings into focus how African American women consume, understand, and make meaning of mediated images and representations of African American women. In order to inform this particular research project, this study engages a constellation of literature and theoretical perspectives and explores historical representations of African American women and beauty messages they contain. Throughout this process I examine concepts of identity formation; discuss connections between sexuality and the politics of imagery; and investigate linkages between structural racism, …

A Case Study Evaluation Of Schoolwide Positive Behavior Support And Its Relationship To Student Well-Being From A Social Justice Perspective, Alissa Briggs

Dissertations

Schoolwide positive behavior support (SWPBS) is proactive, systemic, school-wide intervention aimed at preventing problem behavior and promoting prosocial behavior (Warren et al., 2003). Successful SWPBS implementation relates to reduced office discipline referrals and increased scores on tests of academic achievement (Lassen, Steele, & Sailor, 2006). However, it is not clear how SWPBS relates to other indicators of student well-being (e.g., school climate, safety, relationships, prosocial behavior, and engagement in school). In order to achieve social justice in schools, multiple components of children's well-being must be promoted through proactive interventions (Prilleltensky, 2005), such as SWPBS. Because well-being as a whole encompasses …

Towards A Multidimensional Model Of Adaptation For African American Adolescents Exposed To Racial Discrimination, Jamila Cunningham

Dissertations

The purposes of the current study were to 1) examine the associations of racial discrimination to internalizing symptoms, externalizing symptoms and perceived life satisfaction in African American adolescents, and 2) determine Africultural cluster profiles based on indicators of racial socialization, racial identity and culturally relevant coping strategies 3) examine whether cluster profile buffers stress exposed African American adolescents from increased internalizing symptoms, anger and decreased life satisfaction. One hundred-fifty-one African American adolescents (grades 9th - 12th) from four high schools and a community group from a major Midwest city and a major city from the Southeast reported on exposure to …

Statin-Mediated Attenuation Of Chemokine Expression In Peripheral Nerve Vascular Endothelial Cells, Kelly Ann Langert

Dissertations

Pro-inflammatory cytokines, including tumor necrosis factor-α (TNF-α), play a pivotal role in the pathogenesis of Guillain-Barré Syndrome (GBS), a debilitating autoimmune disorder that affects the peripheral nervous system. By up-regulating endothelial expression of chemokines and cell adhesion molecules (CAMs), TNF-α facilitates the recruitment and trafficking of autoreactive leukocytes across the blood-nerve barrier and into peripheral nerves, an early pathological hallmark of GBS. Literature indicates that TNF-α, monocyte chemoattractant protein-1 (MCP-1), and intercellular adhesion molecule-1 (ICAM-1) are locally increased in patients with GBS, correlating with disease severity. Similar findings have been demonstrated in an animal model of GBS, experimental autoimmune neuritis …

Analysis Of Illicit Drugs, Their Metabolites And Other Micropollutants In Water By Liquid Chromatography Tandem Mass Spectrometry, Deepika P. Panawennage

Dissertations

The goal of this project is to develop liquid chromatography tandem mass spectrometry (LC/MS/MS) methods for the analysis of different, novel micropollutants in waste water and natural water. Micropollutants are compounds that can exert adverse environmental and human health effects at low concentrations. Most of these compounds include personal care products and pharmaceuticals, such as antibiotics and controlled substances. In the first part of this study, we focused in the analysis of illicit drugs and drug metabolites because these analyses have the potential to serve as markers of drug abuse. We have detected over sixteen different illicit drugs and their …

You Had Me At Helen: The Name Letter Effect In Judgments Of Humor, Jenna Ryan

Dissertations

The present study demonstrates that implicit egotism is relevant to not only letter attractiveness ratings on the Name Letter Test (NLT), but also to judgments of humor--albeit to a lesser degree. Respondents participated as "mock" judges in a simulated cartoon caption contest and evaluated writers' caption submissions for two cartoons. It was hypothesized that participants would exhibit biases toward captions submitted by writers with whom they shared a first initial letter, and additionally, their gender. A name letter effect was found in participants' judgments of humor and on the NLT. Shared gender with a caption writer--when coupled with a shared …