Digital Commons Network^™

Study Of Mm-Wave Fixed Beam And Frequency Beam-Scanning Antenna Arrays, Zeeshan Ahmed

Dissertations

Millimeter-wave frequencies are anticipated to be widely adapted for future wireless communication systems to resolve the demand of high data-rate and capacity issues. The millimeter-wave frequency range offers wide spectrum and a shift for most newly developing technologies as the microwave and lower frequency bands are becoming overcrowded and congested. These high frequency bands offer short wavelengths which has enabled the researchers to design and implement compact and adaptable antenna solutions. This research focuses on the implementation, transformation and modification of antenna structures used in lower frequency bands to millimeter-wave applications with high gain and multi-band and wideband performances.

The …

Analysis Of Power Quality Constrained Consumer-Friendly Demand Response In Low Voltage Distributions Network, Chittesh Veni Chandran

Dissertations

Load management using demand response (DR) in a low voltage distribution network (LVDN) offers an economically profitable business platform with peak load management. However, the inconvenience caused to the consumer in depriving their devices and the low levels of associated incentive have contributed to lower consumer acceptance for DR programs in the community. However, with the increasing number of controllable consumer loads, a residential-level DR program is highly plausible in the short to medium term. Further, additional DR capabilities (including ancillary services) are likely to improve the remuneration potential for participants in DR. Considering the perspective of a distribution network …

A Comparison Of Instructional Efficiency Models In Third Level Education, Murali Rajendran

Dissertations

This study investigates the validity and sensitivity of a novel model of instructional efficiency: the parabolic model. The novel model is compared against state-of-the-art models present in instructional design today; Likelihood model, Deviational model and Multidimensional model. This models is based on the assumption that optimal mental workload and high performance leads to high efficiency, while other models assume that low mental workload and high performance leads to high efficiency. The investigation makes use of two instructional design conditions: a direct instructions approach to learning and its extension with a collaborative activity. A control group received the former instructional design …

Coordination, Adaptation, And Complexity In Decision Fusion, Weiqiang Dong

Dissertations

A parallel decentralized binary decision fusion architecture employs a bank of local detectors (LDs) that access a commonly-observed phenomenon. The system makes a binary decision about the phenomenon, accepting one of two hypotheses (H0 (“absent”) or H1 (“present”)). The k 1 LD uses a local decision rule to compress its local observations yk into a binary local decision uk; uk = 0 if the k 1 LD accepts H0 and uk = 1 if it accepts H1. The k 1 LD sends its decision uk over a noiseless dedicated channel to a Data Fusion Center (DFC). The DFC combines the …

Drone-Assisted Emergency Communications, Di Wu

Dissertations

Drone-mounted base stations (DBSs) have been proposed to extend coverage and improve communications between mobile users (MUs) and their corresponding macro base stations (MBSs). Different from the base stations on the ground, DBSs can flexibly fly over and close to MUs to establish a better vantage for communications. Thus, the pathloss between a DBS and an MU can be much smaller than that between the MU and MBS. In addition, by hovering in the air, the DBS can likely establish a Line-of-Sight link to the MBS. DBSs can be leveraged to recover communications in a large natural disaster struck area …

A Deep Machine Learning Approach For Predicting Freeway Work Zone Delay Using Big Data, Abdullah Shabarek

Dissertations

The introduction of deep learning and big data analytics may significantly elevate the performance of traffic speed prediction. Work zones become one of the most critical factors causing congestion impact, which reduces the mobility as well as traffic safety. A comprehensive literature review on existing work zone delay prediction models (i.e., parametric, simulation and non-parametric models) is conducted in this research. The research shows the limitations of each model. Moreover, most previous modeling approaches did not consider user delay for connected freeways when predicting traffic speed under work zone conditions. This research proposes Deep Artificial Neural Network (Deep ANN) and …

Human-Robot Interaction For Assistive Robotics, Jiawei Li

Dissertations

This dissertation presents an in-depth study of human-robot interaction (HRI) withapplication to assistive robotics. In various studies, dexterous in-hand manipulation is included, assistive robots for Sit-To-stand (STS) assistance along with the human intention estimation. In Chapter 1, the background and issues of HRI are explicitly discussed. In Chapter 2, the literature review introduces the recent state-of-the-art research on HRI, such as physical Human-Robot Interaction (HRI), robot STS assistance, dexterous in hand manipulation and human intention estimation. In Chapter 3, various models and control algorithms are described in detail. Chapter 4 introduces the research equipment. Chapter 5 presents innovative theories and …

Experiments And Modeling Of The Chemo-Mechanically Coupled Behavior Of Polymeric Gels, Nikola Bosnjak

Dissertations

Polymeric materials consist of mutually entangled or chemically crosslinked long njitmolecular chains which form a polymer network. Due to their molecular structure, the njitpolymeric materials are known to undergo large deformation in response to various njitenvironmental stimuli, such as temperature, chemical potential and light.

When a polymer network is exposed to a suitable chemical solvent, the solvent molecules are able to diffuse inside the network, causing it to undergo a large volumetric deformation, known as swelling. In addition to volumetric deformation, this process involves the chemical mixing of the polymer network and solvent molecules, and is typically environmentally responsive. A …

Supporting User Interaction And Social Relationship Formation In A Collaborative Online Shopping Context, Yu Xu

Dissertations

The combination of online shopping and social media allow people with similar shopping interests and experiences to share, comment, and discuss about shopping from anywhere and at any time, which also leads to the emergence of online shopping communities. Today, more people turn to online platforms to share their opinions about products, solicit various opinions from their friends, family members, and other customers, and have fun through interactions with others with similar interests. This dissertation explores how collaborative online shopping presents itself as a context and platform for users' interpersonal interactions and social relationship formation through a series of studies. …

Performance Optimization Of Big Data Computing Workflows For Batch And Stream Data Processing In Multi-Clouds, Huiyan Cao

Dissertations

Workflow techniques have been widely used as a major computing solution in many science domains. With the rapid deployment of cloud infrastructures around the globe and the economic benefits of cloud-based computing and storage services, an increasing number of scientific workflows have migrated or are in active transition to clouds. As the scale of scientific applications continues to grow, it is now common to deploy various data- and network-intensive computing workflows such as serial computing workflows, MapReduce/Spark-based workflows, and Storm-based stream data processing workflows in multi-cloud environments, where inter-cloud data transfer oftentimes plays a significant role in both workflow performance …

Small-Scale Dynamics Of Photospheric Magnetic Activities And Their Chromospheric Responses, Jiasheng Wang

Dissertations

The evolution of photospheric magnetic fields is considered as the fundamental source of forming atmospheric structures and triggering most solar activities, including flares and mass ejections on various scales (CMEs, jets, etc.). With the implementation of high-resolution observational instruments, small-scale details of magnetic features are recognized that can provide important information regarding the evolution in active regions and the connection between photospheric magnetic reconnection and jet-like ejections in the quiet Sun. This research takes advantage of the exceptionally high-resolution measurements of vector magnetic field and imaging observations by the Goode Solar Telescope, and UV/EUV imaging observations from space-based instruments. The …

Semantic, Integrated Keyword Search Over Structured And Loosely Structured Databases, Xinge Lu

Dissertations

Keyword search has been seen in recent years as an attractive way for querying data with some form of structure. Indeed, it allows simple users to extract information from databases without mastering a complex structured query language and without having knowledge of the schema of the data. It also allows for integrated search of heterogeneous data sources. However, as keyword queries are ambiguous and not expressive enough, keyword search cannot scale satisfactorily on big datasets and the answers are, in general, of low accuracy. Therefore, flat keyword search alone cannot efficiently return high quality results on large data with structure. …

Countering Internet Packet Classifiers To Improve User Online Privacy, Sina Fathi-Kazerooni

Dissertations

Internet traffic classification or packet classification is the act of classifying packets using the extracted statistical data from the transmitted packets on a computer network. Internet traffic classification is an essential tool for Internet service providers to manage network traffic, provide users with the intended quality of service (QoS), and perform surveillance. QoS measures prioritize a network's traffic type over other traffic based on preset criteria; for instance, it gives higher priority or bandwidth to video traffic over website browsing traffic. Internet packet classification methods are also used for automated intrusion detection. They analyze incoming traffic patterns and identify malicious …

Novel Applications Of Mass Spectrometry For Quantitation And Reaction Mechanism Elucidation, Pengyi Zhao

Dissertations

Mass spectrometry (MS) has been growing as one of the most widely used tools in the field of analytical chemistry. Various applications have been developed to harness the high sensitivity and specificity of mass spectrometric analysis. In this dissertation, two major challenges are addressed. By developing mass spectrometric-based methods, absolute quantitation of proteins/peptides have been achieved. Elucidation of various reaction mechanisms are also enabled. These are the focuses of this dissertation.

In Chapters 2 to 4, a novel quantitation method is developed, titled as coulometric mass spectrometry (CMS). The strength of this method is that no reference standard or isotope-labeled …

A Longitudinal Investigation Of Functional Activity Changes From Vision Therapy: A Study Of Binocularly Normal Controls And Patients With Convergence Insufficiency, Cristian Morales Carrasco

Dissertations

Convergence insufficiency (CI) is a binocular vision dysfunction in which the person has difficulty maintaining a sustained fixation on an object in the near field of view. This condition is present in about 5% of the general population and with a greater prevalence in patients with traumatic brain injury or attentional deficit hyperactivity disorder. One therapeutic intervention for CI is Office-Based Vergence and Accommodative therapy (OBVAT) which is successful in about 75% of the pediatric and young adult population. The neural mechanism by which OBVAT leads to a sustained reduction in visual symptoms is not fully understood. Vergence eye movements …

Addressing Ad-Blocking Challenges In Online Publishing: A Data Science Approach, Shuai Zhao

Dissertations

The revenue of online display advertising is expected to reach 389 billion U.S. dollars globally in 2021. However, the fast increase in ad-blocker usage impacts publishers' ad revenue and the ad-supported free web. Faced with this problem, many online publishers choose either to cooperate with ad-blocker software companies to show acceptable ads or to build a wall that requires users to whitelist (i.e., turn off ad-blockers) for content access. This dissertation aims to deepen the understanding of existing counter-ad-blocking strategies and further explore how to address ad-blocking challenges through a data science approach.

The dissertation starts with investigating and identifying …

Mental Health And The High-Performing Student: A Study Of Stressors And Effective Supports For High-Achieving High School Students, Jodi Boyle

Dissertations

Purpose: The purpose of this qualitative phenomenological study was to explore the lived experiences of high-achieving 11th- and 12th-grade high school students participating in International Baccalaureate (IB), Advanced Placement (AP), or Honors courses. An additional purpose of this study was to identify the academic and social stressors experienced by students and the coping strategies used to overcome them.

Methodology: This study used a phenomenological research design to describe the lived experiences, academic and social stressors, and coping strategies of high-achieving students. For this study, in-depth interviews were conducted to understand the academic and social experiences of students participating in …

A Phenomenological Study On The Impact Of Servant Leadership For Establishing A Culture Of High Performance As Perceived By High School Principals, Darrick Rice

Dissertations

Purpose: The purpose of this phenomenological study was to explore and describe the perceived impact of Patterson’s (2003) 7 servant leadership constructs on high school principals in establishing a culture of high performance.

Methodology: The qualitative phenomenological study described the lived experiences of high school principals who lead schools that have implemented Patterson's (2003) 7 servant leadership constructs for establishing a culture of high performance in Los Angeles County, California. The researcher was a part of 8 peer researchers and 2 faculty advisors. The data collection included virtual face-to-face semi structured interviews using a protocol developed by the thematic team. …

An Educational Initiative To Prevent Unnecessary Hospitalization For Hospice Patients, Alkeisha H. Mims

Dissertations

Avoidable hospitalizations of hospice patients cost Medicare $3 billion a year. When hospice nurses are able to identify early signs and symptoms of acute illness and provide appropriate interventions to prevent such admissions, 20-60% of the hospitalizations are preventable. The practice problem addressed in this quality improvement doctor of nursing project was the 30% hospital admission rate of hospice patients as evidenced by chart review, admission data, and revocation data. The first purpose of the project was to identify evidence-based nursing care paths in the literature for the top 5 medical diagnoses related to avoidable hospital admissions. The second purpose …

Exploring The Relationships Between And Among Registered Nurses' Spiritual Well-Being, Spiritual Care Perspectives, And Their Provision Of Spiritual Care In Acute Care Settings, Barbara J. Kitchener

Dissertations

Despite acknowledgment that spiritual care is an essential aspect of holistic nursing care, nurses often feel ill-prepared for, uncomfortable with, and uncertain about providing spiritual care. Studies have indicated that nurses who have a strong sense of their own spiritual well-being and/or a positive perspective [attitude, value, belief] about spiritual care are more inclined to provide spiritual care to their patients. However there is a scarcity of such studies among acute care nurses. This descriptive correlational study aimed to explore relationships between and among acute care nurses' spiritual well-being (SWB), spiritual care perspectives (SCP), and their provision of spiritual care …

The Experience Of Living With Hypertension: Lessons From A Cohort Of Older Men, Junjira Seesawang

Dissertations

Poor adherence to treatment and poorly controlled hypertension are common in older men, especially in rural areas. Knowledge about the experience of living with hypertension among older men is important for developing nursing practices to enhance treatment adherence. However, little is known about the personal experiences of older men with hypertension. This dissertation includes three papers that address the following: (1) the experiences of men with hypertension, based on a review of literature, (2) factors influencing the ability to self-manage hypertension among older adults in Asian countries, based on a review of qualitative studies, and (3) grounded theory study exploring …

A Study To Determine The Relationships Among Grit, Engagement, And Student Achievement, Jill Dennison

Dissertations

In the absence of high quality and impact interventions, undesirable consequences of poverty will be seen to fruition. In this study, the Golden Circle business model (Sinek et al., 2017) served as the framework to understand how students’ grit, engagement, and achievement are related in Title I elementary schools. The purpose of this study was to determine if there is a relationship between grit and engagement, engagement and student achievement, and finally grit and student achievement. The relationship between grit and engagement was measured by teacher and student perceptions, respectively. Student engagement and achievement were analyzed using student self-perceptions of …

Leadership Behaviors Needed By Executive Directors Of Nonprofit Victim Support Organizations, Timothy Hunt

Dissertations

Purpose: The purpose of this mixed methods study was to determine how nonprofit victim support organization leaders rate the impact of the 10 Transformational Leadership Skills Inventory (TLSi) domains on their effectiveness. In addition, it was the purpose to discover how nonprofit victim support organization leaders describe the impact of each TLSi domain on their effectiveness.

Methodology: The participants in this study were executive directors of private, nonprofit victim support organizations across the Pacific Northwest region of Washington, Oregon, and Idaho. All participated in an online quantitative survey where they rated their agreement with statements about the impact of the …

Phenomenological Study On The Impact Of Servant Leadership For Establishing A Culture Of High Performance As Perceived By Public School District Superintendents, Robin Stout

Dissertations

Purpose: The purpose of this phenomenological study was to explore and describe K12 public school superintendents’ perceived impact of the seven servant leadership constructs established by Patterson (2003) on establishing a culture of high performance.

Methodology: This phenomenological research study identified and described the extent to which superintendents perceived the impact servant leadership has on establishing a culture of high performance. Eight participants were selected through non probability purposeful and convenience sampling based on specific criteria including a minimum of three years of experience at their current district and a minimum of five years of experience as a superintendent. The …

An Examination Of Indicators Regarding Student Choice In Social Media Marketing And Platforms Of Higher Education Institutions In Missouri, Emmy J. Zimmerman

Dissertations

The purpose of this study is to investigate relationships between social media marketing, social media platforms, and student choice of higher education institutions. Through evaluating current research, this study addresses potential changes needed to ensure colleges’ and universities’ marketing and admissions teams are using social media in ways that increase return on investment (ROI) and attract students to institutions. Previous research exposed social media marketing as a relatively untested method of reach for students’ college choice; therefore, the study will be original in nature. Previous studies provided data from an admissions counselor’s perspective, notably, a study by Barnes and Jacobsen …

The Effects Of Principal Feedback On Instruction And Student Achievement, Jeremy Brownfield

Dissertations

Legislative and educational reform through the first 20 years of this century has focused largely on the impact of the teacher and principal on student achievement (Kraft & Gilmour, 2016; Marshall, 2017). Principals’ influence upon achievement is second only to that of classroom teachers; however, principal impact is indirect and difficult to quantify (Leithwood, Louis, Anderson, & Wahlstorm, 2004). This mixed-methods study involved the analysis of secondary data and elicitation of teachers’ and principals’ perceptions in order to determine the impact of principals on student achievement. The quantitative portion of the study involved an analysis of secondary data including the …

Al-Baghdadi And The Art Of Terrorist Persuasion, Bandar Dawshi

Dissertations

This dissertation examines the rhetoric used by ISIS leader Abu Bakr al-Baghdadi to persuade thousands of young Muslims around the world to join the organization and defend it until the end. The dissertation concerns the innovative methods used by the organization to reach thousands of young people around the world, and the role of misinterpretations of the Qur'an in supporting al-Baghdadi's rhetorical arguments. In order to provide a reasonable explanation for these speeches, the dissertation used Aristotle's rhetorical methodology, Gamal Abdel Nasser's rhetorical concept, Burke's concept of identity and social identity theory. The arguments focused on studying rhetoric within the …

Impact Of Transformational Leadership Behaviors Of Administrators As Predictors Of High Performing And Low Performing Schools In Mississippi, Audra Rester

Dissertations

The purpose of this study was to develop an understanding of the relative impact of principal transformational leadership as it relates to school accountability status. Teachers from schools that have been assigned the labels of A, B, C, D, and F by the Mississippi Department of Education were surveyed. A quantitative design was used to test six research hypotheses to see if any differences exist between the perceived leadership behaviors of school administrators by teachers among the accountability labels. The principal leadership behaviors, which were based on transformational leadership theory, were (1) provides vision, (2) models appropriate behavior, (3) fosters …

Diversity And Inclusion: Examining The Lived Experiences Of Lgbtq Students At Historically Black Colleges And Universities (Hbcus) In The Bible Belt, Steven Jones

Dissertations

Throughout the twentieth century, the Gay Rights Movement has gained momentum as LGBTQ (Lesbian, Gay, Bisexual, Transgender, Queer) individuals have fought for civil equality and social acceptance. However, Historically Black Colleges and Universities (HBCUs) have been slow to adapt, implement, and effect change that improves the quality of education for LGBTQ students. Strong religious beliefs derived from the church; especially in the South, may be the connection to understanding why homosexuality isn’t vastly accepted or celebrated in the Black Community and at HBCUs; particularly, in the Bible Belt.

Thus, this phenomenological qualitative study, guided by the theory of care framework, …

Well-Being Indicators, Social Globalization, And Unaccompanied Child Migration From Central America, Lucia Farriss

Dissertations

This research investigates the effect of well-being indictors and social globalization on the migration of Unaccompanied Alien Children (UAC) from Central America. The purpose of this study is to determine whether the surge in UAC that began in 2014 at the United States southern border is driven primarily by violence, or whether other factors are at play. Using data for the period 2008-2018, the apprehension of UAC serves as a proxy for measuring unaccompanied child migration to the United States. The four countries of focus are El Salvador, Guatemala, Honduras, and Mexico as they contribute the largest numbers of child …