Digital Commons Network^™

New Techniques For Improving Biological Data Quality Through Information Integration, Katherine Grace Herbert

Dissertations

As databases become more pervasive through the biological sciences, various data quality concerns are emerging. Biological databases tend to develop data quality issues regarding data legacy, data uniformity and data duplication. Due to the nature of this data, each of these problems is non-trivial and can cause many problems for the database. For biological data to be corrected and standardized, methods and frameworks must be developed to handle both structural and traditional data.

The BIG-AJAX framework has been developed for solving these problems through both data cleaning and data integration. This framework exploits declarative data cleaning and exploratory data mining …

Non-Parametric Algorithms For Evaluating Gene Expression In Cancer Using Dna Microarray Technology, Virginie Aris

Dissertations

Microarray technology has transformed the field of cancer biology by enabling the simultaneous evaluation of tens of thousands mRNA expression levels in a single experiment. This technology has been applied to medical science in order to find gene expression markers that cluster diseased and normal tissues, genes affected by treatments, and gene network interactions. All methods of microarray data analysis can be summarized as a study of differential gene expression. This study addresses three questions, 1) the roles of selectively expressed genes for the classification of cancer, 2) issues of accounting for both experimental and biological noise, and 3) issues …

Relationship Analysis : Improving The Systems Analysis Process, Joseph Thomas Catanio

Dissertations

A significant aspect of systems analysis involves discovering and representing entities and their inter-relationships. Guidelines exist to identify entities but do not provide a rigorous and comprehensive process to explicitly capture the relationship structure of the problem domain. Whereas, other analysis techniques lightly address the relationship discovery process, Relationship Analysis is the only systematic, domain-independent analysis technique focusing exclusively on a domain's relationship structure.

The quality of design artifacts, such as class diagrams, and development time necessary to generate these artifacts can be improved by first representing the complete relationship structure of the problem domain. The Relationship Analysis Model is …

Characterization Of Ultrathin Gate Dielectrics And Multilayer Charge Injection Barriers, Edwin M. Dons

Dissertations

Since the invention of the first integrated circuit, the semiconductor industry has distinguished itself by a phenomenally rapid pace of improvements in device performance. This trend of ever smaller and faster devices is a result of the ability to exponentially reduce feature sizes of integrated circuits, a trend commonly known as "scaling". A reduction of overall feature sizes requires a simultaneous reduction in the thickness of the gate dielectric, SiO₂, of a MOSFET. Gate oxides in the ultrathin regime (<35 A) feature a large direct tunneling leakage current. The presence of this leakage current requires a reevaluation of standard characterization techniques as well as a reevaluation of the continued usefulness of SiO₂ as the gate dielectric of choice for future applications. On the other hand, a thorough understanding of …

Understanding The Origin Of The Recovery Of Superconductivity In Halogenated Ybco Single Crystal : Atomic Structure Study, Lamine Mohamed Kollakoye Dieng

Dissertations

The recovery of superconductivity in underdoped YBa₂Cu₃O_6+y (YBCO) by exposure to bromine, iodine, chlorine and fluorine is a long-standing problem which has not been clearly resolved. The key question concerns the role of these halogens in the lattice. In order to shed light to this problem, we have performed multiple-edge x-ray absorption fine structure (XAFS) measurements about the Y K, Ba L₃, I L₃, Cu K and Br K-edges at room temperature on brominated (non-brominated) and iodinated (non-iodinated) YBCO single crystals. Our XAFS results at the Br K (brominated) and I …

Performance Evaluation Of Communication Systems With Transmit Diversity, Chunjun Gao

Dissertations

Transmit diversity is a key technique to combat fading with multiple transmit antennae for next-generation wireless communication systems. Space-time block code (STBC) is a main component of this technique. This dissertation consists of four parts: the first three discuss performance evaluation of STBCs in various circumstances, the fourth outlines a novel differential scheme with full transmit diversity.

In the first part, closed-form expressions for the bit error rate (BER) are derived for STBC based on Alamouti's scheme and utilizing M-ary phase shift keying (MPSK) modulation. The analysis is carried out for a slow, flat Rayleigh fading channel with coherent detection …

Efficient Similarity Search In High-Dimensional Data Spaces, Yue Li

Dissertations

Similarity search in high-dimensional data spaces is a popular paradigm for many modern database applications, such as content based image retrieval, time series analysis in financial and marketing databases, and data mining. Objects are represented as high-dimensional points or vectors based on their important features. Object similarity is then measured by the distance between feature vectors and similarity search is implemented via range queries or k-Nearest Neighbor (k-NN) queries.

Implementing k-NN queries via a sequential scan of large tables of feature vectors is computationally expensive. Building multi-dimensional indexes on the feature vectors for k-NN search also tends to be unsatisfactory …

A Discovery And Analysis Of Influencing Factors Of Pair Programming, Kyungsub Steve Choi

Dissertations

The exploration into the underlying psychosocial links of pair programming. a new and unorthodox programming paradigm in which two programmers share one keyboard and monitor during real-time programming sessions, is undertaken. These complex psychosocial relationships, along with cognitive process exchanges, ultimately mold the programming output as well as determine the level of communication, satisfaction. confidence and compatibility. Laying the framework for this research, a through review of traditional and contemporary paradigms with a special focus on their limitations and a list of current software development problems are presented. Next, a detailed summary of pair programming and related agile software paradigms, …

On Ip Over Wdm Burst-Switched Long Haul And Metropolitan Area Networks, Jingxuan Liu

Dissertations

The IP over Wavelength Division Multiplexing (WDM) network is a natural evolution ushered in by the phenomenal advances in networking technologies and technical breakthroughs in optical communications, fueled by the increasing demand in the reduction of operation costs and the network management complexity. The unprecedented bandwidth provisioning capability and the multi-service supportability of the WDM technology, in synergy with the data-oriented internetworking mechanisms, facilitates a common shared infrastructure for the Next Generation Internet (NGJ).

While NGI targets to perform packet processing directly on the optical transport layer, a smooth evolution is critical to success. Intense research has been conducted to …

Studies Of Disk Arrays Tolerating Two Disk Failures And A Proposal For A Heterogeneous Disk Array, Chunqi Han

Dissertations

There has been an explosion in the amount of generated data in the past decade. Online access to these data is made possible by large disk arrays, especially in the RAID (Redundant Array of Independent Disks) paradigm. According to the RAID level a disk array can tolerate one or more disk failures, so that the storage subsystem can continue operating with disk failure(s). RAID 5 is a single disk failure tolerant array which dedicates the capacity of one disk to parity information. The content on the failed disk can be reconstructed on demand and written onto a spare disk. However, …

A Gibbs Sampling Approach To Maximum A Posteriori Time Delay And Amplitude Estimations, Michele Picarelli

Dissertations

Research concerned with underwater propagation in a shallow ocean environment is a growing area of study. In particular, the development of fast and accurate computational methods to estimate environmental parameters and source location is desired. In this work, only select features of the acoustic field are investigated, namely, the time delays and amplitudes of individual paths, the signal-to-noise ratio, and the number of multi-path arrivals. The amplitudes and delays contain pertinent information about the geometry associated with the environment of interest. Estimating the time delays and amplitudes of select paths in a manner that is both accurate and time efficient, …

Multi-Rate Access Schemes And Successive Interference Cancellation For Wireless Multimedia Mc-Cdma Communications, Mizhou Tan

Dissertations

To catch up with the fast changes of the information challenges, providing multimedia services has become a very important requirement for future wireless communications. A proper system, capable of supporting multi-rate transmissions as well as handling high quality of service (QoS) requirements in hostile wireless communication environments, should be sought. Multi-carrier CDMA (MC-CDMA), a combination of multi-carrier modulation (MCM) and direct-sequence CDMA (DS-CDMA), appears to be one of the most elegant solutions. In this dissertation, four multi-rate access schemes, termed uncoded fixed spreading length (UFSL), coded fixed spreading length (CFSL), multi-code fixed spreading length (MFSL) and variable spreading length (VSL), …

Boron And Phosphorous Implantation Into (100) Germanium : Modeling And Investigation Of Dopant Annealing Behavior, Yong Seok Suh

Dissertations

Germanium is increasingly being considered at this time for future silicon compatible optoelectronic and complementary metal oxide semiconductor (CMOS) device application. Germanium implantation will be a critical process for future device fabrication. However, critical properties like Pearson parameters and dopant activation temperatures are not well established. In this study, boron and phosphorus were implanted into (100) germanium with energies ranging from 20 to 320 keV and doses of 5 x 10¹³ to 5 x 10¹⁶ cm^-2. The behavior of the boron and phosphorus before and after annealing for 3 hours at 400, 600 or 800°C in …

3-D Numerical Simulation Of Reactive Extrusion And Its Application To Polymerization Of Ε-Caprolactone In Co-Rotating Twin-Screw Extruders, Linjie Zhu

Dissertations

A 3-D numerical simulation model was proposed to predict the polymerization of ε-caprolactone in fully-filled conveying elements and kneading blocks of co-rotating twin-screw extruders, in which the kinetics equation for polymerization is coupled with continuity equation, momentum equation, and energy equation. With the 3-D model, parametric studies have been carried out to investigate the effects of screw configurations, screw diameter, operational conditions, values of heat from reaction, initiator concentration, and heat transfer conditions at barrel surface upon the polymerization progress. Two simulation models for the polymerization in the partially-filled channels were developed based on the conveying mechanisms of the reaction …

Phase Noise Effects On Ofdm : Analysis And Mitigation, Songping Wu

Dissertations

Orthogonal frequency division multiplexing (OFDM) is a promising technique which has high spectrum efficiency and the robustness against channel frequency selectivity. One drawback of OFDM is its sensitivity to phase noise. It has been shown that even small phase noise leads to significant performance loss of OFDM. Therefore, phase noise effects on OFDM systems need to be analyzed and methods be provided to its mitigation.

Motivated by what have been proposed in the literature, the exact signal to interference plus noise ratio (SINR) is derived in this dissertation for arbitrary phase noise levels. In a multiple access environment with multiple …

Statistical Anomaly Denial Of Service And Reconnaissance Intrusion Detection, Zheng Zhang

Dissertations

This dissertation presents the architecture, methods and results of the Hierarchical Intrusion Detection Engine (HIDE) and the Reconnaissance Intrusion Detection System (RIDS); the former is denial-of-service (DoS) attack detector while the latter is a scan and probe (P&S) reconnaissance detector; both are statistical anomaly systems.

The HIDE is a packet-oriented, observation-window using, hierarchical, multi-tier, anomaly based network intrusion detection system, which monitors several network traffic parameters simultaneously, constructs a 64-bin probability density function (PDF) for each, statistically compares it to a reference PDF of normal behavior using a similarity metric, then combines the results into an anomaly status vector that …

Ad Hoc Network Security And Modeling With Stochastic Petri Nets, Congzhe Zhang

Dissertations

Advances in wireless technology and portable computing along with demands for high user mobility have provided a major promotion toward the development of ad hoc networks. These networks feature dynamic topology, self-organization, limited bandwidth and battery power of a node. Unlike the existing commercial wireless systems and fixed infrastructure networks, they do not rely on specialized routers for path discovery and traffic routing. Security is an important issue in such networks. Typically, mobile nodes are significantly more susceptible to physical attacks than their wired counterparts.

This research intends to investigate the ad hoc network routing security by proposing a performance …

Uncertainty Analysis In Ecological Risk Assessment Modeling, Tepwitoon Thongsri

Dissertations

A probabilistic approach employing Monte Carlo simulations for assessing parameter and risks as probabilistic distributions was used in an ecological risk assessment (ERA) model to characterize risk and address uncertainty. This study addresses the following sources of uncertainty: parameter inputs in the ERA models, risk algorithms and uncertain input concentrations. To achieve this objective, both sensitivity and uncertainty analyses are being conducted. Monte Carlo simulations were used for generating probabilistic distributions of parameter and model uncertainty. All sensitivity, uncertainty, and variability analyses were coded in Visual Basic as part of the ERA model software version 2001, which was developed under …

Transmission And Detection For Space-Time Block Coding And V-Blast Systems, Lei He

Dissertations

This dissertation focuses on topics of data transmission and detection of space -time block codes (STBC). The STBCs can be divided into two main categories, namely, the orthogonal space-time block codes (OSTBC) and the quasi-orthogonal space-time codes (Q-OSTBC). The space-time block coded systems from transceiver design perspective for both narrow-band and frequency selective wireless environment are studied. The dissertation also processes and studies a fast iterative detection scheme for a high-rate space-time transmission system, the V-BLAST system.

In Chapter 2, a new OSTBC scheme with full-rate and full-diversity, which can be used on QPSK transceiver systems with four transmit antennas …

Hybrid Routing And Bridging Strategies For Large Scale Mobile Ad Hoc Networks, Sheng Xu

Dissertations

Multi-hop packet radio networks (or mobile ad-hoc networks) are an ideal technology to establish "instant" communication infrastructure for military and civilian applications in which both hosts and routers are mobile. In this dissertation, a position-based/link-state hybrid, proactive routing protocol (Position-guided Sliding-window Routing - PSR) that provides for a flat, mobile ad-hoc routing architecture is described, analyzed and evaluated. PSR is based on the superposition of link-state and position-based routing, and it employs a simplified way of localizing routing overhead, without having to resort to complex, multiple-tier routing organization schemes. A set of geographic routing zones is defined for each node, …

Nonlinear Long-Wave Interfacial Stability Of Two-Layer Gas-Liquid Flow, Tetyana Segin

Dissertations

The flow of two immiscible viscous fluids in a thin inclined channel is considered, in either a cocurrent or countercurrent regime. Following the air-water case, which is found in a variety of engineering systems, we allow the upper fluid to be either compressible or incompressible. The disparity of the length scales and the density and viscosity ratios of the two fluids is exploited through a lubrication approximation of the conservation of mass and the Navier-Stokes equations. As a result of this long-wave theory, a coupled nonlinear system of partial differential equations is obtained that describes the evolution of the interfacial …

Total Resource Sharing Among Collegiate And Public Libraries In The Commonwealth Of The Northern Mariana Islands: A Narrative Case Study, Jimmie L. Ellis Edd

Dissertations

Especially in difficult economic times, educational and public sector organizations are under pressure to do more with less. At times, this means consolidating organizations to avoid costly duplication. This study focused on three attempts at consolidation that occurred on the island of Saipan and the two major outer islands of the Commonwealth of the Northern Mariana Islands (CNMI). These efforts entailed total resource sharing across the collegiate and public libraries on these islands. Total resource sharing among the collegiate and public libraries in the CNMI was first envisioned in the late 1980s and early 1990s. By 1994, the concept of …

An Examination Of Teachers’ Beliefs About Critical Reading And Academic Writing, Cindi Davis Harris Edd

Dissertations

The ability to compose a well-written research paper is evidence o f a student's ability to read critically and write academically. However, evidence suggests that many college-bound high school graduates have not learned these skills. While the research literature overwhelmingly supports the notion that teachers are an important factor in students’ academic success, and that in order to be academically successful, students need to have critical reading and writing skills, there has been little research about how teachers' beliefs and knowledge about critical reading and academic writing influence instruction with regard to these skills. This naturalistic case study employed in-depth …

Functioning Among Taiwanese Families With A Child Having Duchenne Muscular Dystrophy, Jih-Yuan Chen Phd, Msn, Rn

Dissertations

A cross-sectional study was designed to determine the factors with functioning among Taiwanese families with a child having Duchenne Muscular Dystrophy (DMD). This research investigated the level of a child's mobility upon family hardiness, functioning, and support from a family perspective. A total sample of 126 of participants was parents of children with DMD. Parents completed basic demographic information, the Family Assessment Device, Family Hardiness Index, Duke Health Profile, and Family APGAR. Pearson Correlation Coefficient test was performed to examine relationships between independent and dependent variables. To determine if the levels of child's mobility, family characteristics, family hardiness, family health, …

Explicit Writing Instruction: Effects On Sixth Grade Students’ Writing And Reading Achievement, Jennifer Hamby Edd

Dissertations

The purpose of this quantitative study was to examine the effect of explicit writing instruction on sixth grade students' writing growth and achievement as measured by holistic and analytic assessment. This research responds directly to the need for additional research on effective reading and writing instruction (Langer & Allington, 1992; The College Board, 2003). The preponderance of research in writing has been devoted to early writing. Less evidence is available to examine the effect of writing instruction at the sixth grade level. Writing samples from 124 sixth grade students at two elementary schools were used in this study. The two …

Examining The Lived Experiences Of Out Gay And Lesbian K-12 Educators, William Dejean Edd

Dissertations

The purpose of this study was to examine the lived experience of gay and lesbian K-12 educators who consider themselves out within the classrooms in which they teach. With gay and lesbian issues receiving increased visibility within the K-12 setting, researchers have begun to examine the experiences of gay and lesbian K-12 educators (Harbeck, 1992; Letts IV & Sears, 1999; Jennings, 1994; Kissen, 1996; Parker, 2001; Sanlo, 1999) within this context. Yet few research studies have specifically examined gay and lesbian educators who consider themselves out in the classroom in which they teach. Five gay male teachers and five lesbian …

Webquest Design Strategies: A Case Study Measuring The Effect Of The Jigsaw Method On Students’ Personal Agency Beliefs, Engagement, And Learning, James P. Frazee Edd

Dissertations

The WebQuest model continues to grow in popularity, with teachers from around the world and many teacher-educators and experts in the field of educational technology espousing its potential to extend content knowledge and promote higher level thinking. While the model is well received by teachers and students alike, most evidence of its effectiveness is anecdotal, and there is very little in the way of empirical research on the elements that make an effective WebQuest. Furthermore, rich descriptions of how students interact during a well-developed WebQuest are largely absent from the literature. In short, the WebQuest model suffers from a lack …

Keeping Safe: Field Public Health Nurses' Perceptions, Karen Nielsen-Menicucci Phd, Ms, Rn, Phn

Dissertations

By the year 2005, there will be an estimated 1.25 million workers involved in providing nursing care to individuals in their homes (Bureau of Labor Statistics, 1997). There is limited empirical data available on the issue of safety of nurses within the context of home visiting or in the public health venue. Recent research on safety in home visiting has focused on home health rather than public health nursing. The purpose of this study was to explore and explain the perception of safety among field public health nurses. A purposive sample of 19 public health nurses employed in an official …

Increasing The Awareness Of Human Resource Development Activities In Small Firms, Hanacho Michael Nmom

Dissertations

Much of what is known today concerning organizational human resource development efforts (those being employee training, education, and development activities) has steadily and favorably come from large firms. Conversely, very little is known about the extent of HRD activities in small firms, especially those with fewer than 300 employees. To correct this imbalance of awareness the primary aim of this study is to delineate the learning activities of four successfulsmall service-oriented firms in Kalamazoo (Michigan) county.

The study sample consists of seven "purposeful informants". A mixed-method case study, employing the quantitative and qualitative fact-finding strategies ofa simple survey questionnaire and …

Increasing Organization Capacity: A Systems Approach Utilizing Transformational And Distributed Leadership Practices, Patricia L. Reeves

Dissertations

The purpose of this study was to test a transformational, systemic change framework designed by the researcher to assist school leaders who are attempting to incorporate the major elements of transformational leadership theory, systems theory, and organizational development theory into their school or school district operations. The study involved both the distillation and organization of the major theoretical elements from the literature into an operational framework for planning, conducting, and monitoring the systemic change process in K-12 school systems. This framework was, then, tested by the researcher for its descriptive power in a case study analysis of an actual school …