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USF Tampa Graduate Theses and Dissertations

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Exploring Mathematics Teacher Education Fieldwork Experiences Through Storytelling, Melody Jeane Elrod Feb 2017

Exploring Mathematics Teacher Education Fieldwork Experiences Through Storytelling, Melody Jeane Elrod

USF Tampa Graduate Theses and Dissertations

Throughout the history of teacher education, the final fieldwork experience has often been called the single most influential experience in teacher preparation programs (Burns, Jacobs, & Yendol-Hoppey, 2016; Feiman-Nemser & Buchmann, 1986; Parker-Katz & Bay, 2008). Though this experience has been expanded to include fieldwork experiences throughout many teacher education programs (Guyton & McIntyre, 1990), the final fieldwork experience remains the closing activity and the lasting image of teacher preparation (Feiman-Nemser & Buchmann, 1986; Rosaen & Florio-Ruane, 2008). Given its importance, though, researchers know relatively little about it. “The knowledge thus produced is akin to the quantum theory of physics; …


Lilliput Effect Dynamics Across The Cretaceous-Paleogene Mass Extinction: Approaches, Prevalence, And Mechanisms, Matthew Brett Jarrett Dec 2016

Lilliput Effect Dynamics Across The Cretaceous-Paleogene Mass Extinction: Approaches, Prevalence, And Mechanisms, Matthew Brett Jarrett

USF Tampa Graduate Theses and Dissertations

An organism's body size entails both physiological and ecological costs. Furthermore, as a parameter in analyzing organisms, it represents a fundamental and essential morphometric character. Reductions in size following mass extinction is a commonly observed phenomenon in the fossil record. This study examines the evolutionary significance of this phenomenon termed the: 'Lilliput Effect' by proposing that it represents a rapid evolutionary response to altered selection pressures during a mass extinction. This primary hypothesis is evaluated against two additional hypotheses of size reduction: 1) stunted growth as a response to stressed ecosystems, and/or 2) mass extinctions are size selective.

These hypotheses …


Storm Induced Beach Profile Changes Along The Coast Of Treasure Island, West-Central Florida, U.S.A., Zhaoxu Zhu Nov 2016

Storm Induced Beach Profile Changes Along The Coast Of Treasure Island, West-Central Florida, U.S.A., Zhaoxu Zhu

USF Tampa Graduate Theses and Dissertations

Storms play a significant role in beach morphodynamics. Storm-induced beach-profile changes and their longshore variations are investigated in this study. The impacts of four summer tropical storms and two series of winter storms over the last 10 years along the coast of Treasure Island were documented. Tropical storms Alberto in 2006, Fay in 2008, Debby in 2012, Hermine in 2016 and winter storms in winter seasons of 2014 and 2015 are discussed in this study. In general, the Treasure Island beach experienced more erosion generated by tropical storms with greater intensity, but shorter duration, as compared to winter storms due …


A Longitudinal Examination Of A Ssi-Embedded Experiential Environmental Education Course And Environmental Behaviors, Mark H. Newton Nov 2016

A Longitudinal Examination Of A Ssi-Embedded Experiential Environmental Education Course And Environmental Behaviors, Mark H. Newton

USF Tampa Graduate Theses and Dissertations

A perennial goal of environmental education is to produce a scientifically literate citizenry capable of negotiating and resulting complex environmental problems. Popular methods of environmental education instruction tend to overemphasize scientific content knowledge and neglect to consider ethical and moral aspects of the problem. This qualitative study examines the longitudinal association between an experiential environmental education course infused with SSI instruction and students’ environmental behaviors. The results indicate that several students’ conceptualizations of contentious environmental issues change after completing the course and specifically. Furthermore, students’ willingness to act to resolve contentious environmental issues was most closely associated with their environmental …


The Perspectives Of Core Academic Middle School Teachers Regarding Career Education Under Different School Settings, Meredith Leigh Bogush Nov 2016

The Perspectives Of Core Academic Middle School Teachers Regarding Career Education Under Different School Settings, Meredith Leigh Bogush

USF Tampa Graduate Theses and Dissertations

The purpose of this study was to quantify core academic middle school teachers’ (English/language arts, mathematics, science, and social science) perspectives of career education. Prior research denotes that if career education exposure and awareness is provided in middle school grades, then students have the potential to develop a valuable understanding of various occupations available in the future (Akos, Konold, & Niles, 2004). Students observe what the work accomplishes and the effort required for the employee to be successful. If the occupation interests the students, then an increased motivation to complete their studies is likely to develop as they see the …


Improved 2d And 3d Resistivity Surveys Using Buried Electrodes And Optimized Arrays: The Multi-Electrode Resistivity Implant Technique (Merit), Henok Gidey Kiflu Nov 2016

Improved 2d And 3d Resistivity Surveys Using Buried Electrodes And Optimized Arrays: The Multi-Electrode Resistivity Implant Technique (Merit), Henok Gidey Kiflu

USF Tampa Graduate Theses and Dissertations

This thesis presents a novel resistivity method called Multi-Electrode resistivity technique (MERIT) that is used for high resolution imaging of complex geologic features at depth and near the edges of survey lines. The MERIT electrodes are especially shaped and designed to be self-driven using a robust-direct push technique. Measurements are taken using optimized arrays that are generated using a modified version of the “Compare-R” optimization algorithm. This work focused on both two-dimensional (MERIT2D) and three-dimensional (MERIT3D) applications of the buried array and show the relevance of the additional information gained by the addition of deep electrodes especially in sites with …


Reduced Dimensionality Effects In Gd-Based Magnetocaloric Materials, Hillary Faith Belliveau Nov 2016

Reduced Dimensionality Effects In Gd-Based Magnetocaloric Materials, Hillary Faith Belliveau

USF Tampa Graduate Theses and Dissertations

Magnetic refrigeration based on the magnetocaloric effect (MCE) is a promising alternative to conventional gas compression based cooling techniques. Understanding impacts of reduced dimensionality on the magnetocaloric response of a material such as Gadolinium (Gd) or its alloys is essential in optimizing the performance of cooling devices, which is also the overall goal of this thesis. We have determined, in the first part of the thesis, that laminate structures of pure Gd produced by magnetron sputtering have several disadvantages. The target material (pure Gd), ultra-high vacuum components, and the electrical energy it takes to run the manufacturing process are all …


Resonant Light Scattering From Semiconductor Quantum Dots, Kumarasiri Konthasinghe Nov 2016

Resonant Light Scattering From Semiconductor Quantum Dots, Kumarasiri Konthasinghe

USF Tampa Graduate Theses and Dissertations

In this work, resonant laser spectroscopy has been utilized in two major projects --resonance fluorescence measurements in solid-state quantum-confined nanostructures and laser-induced fluorescence measurements in gases. The first project focuses on studying resonant light-matter interactions in semiconductor quantum dots "artificial atoms" with potential applications in quantum information science. Of primary interest is the understanding of fundamental processes and how they are affected by the solid-state matrix. Unlike atoms, quantum dots are susceptible to a variety of environmental influences such as phonon scattering and spectral diffusion. These interactions alter the desired properties of the scattered light and hinder uses in certain …


Photocatalytic Reduction Of Co2 With Tunable Bandgap And Bandedge Materials, Thuhuong T. Ngo Nov 2016

Photocatalytic Reduction Of Co2 With Tunable Bandgap And Bandedge Materials, Thuhuong T. Ngo

USF Tampa Graduate Theses and Dissertations

Solar energy is a sustainable resource which has substantial potential to meet the increasing demand for renewable energy. Though there has been some success in harvesting solar energy for electricity production, converting solar energy to chemical energy as fuels is still a challenge due to low efficiency.

Since the discovery of TiO2 photocatalysts for splitting water (4) and reducing CO2 (5) to form useful chemical feedstock such as H2, CO and CH4, much research has been done to increase the efficiency of photocatalysts. However, the current conversion efficiency of photocatalysts remains low (~5%) (6, …


Confinement Effects And Magnetic Interactions In Magnetic Nanostructures, Kristen Lee Stojak Repa Nov 2016

Confinement Effects And Magnetic Interactions In Magnetic Nanostructures, Kristen Lee Stojak Repa

USF Tampa Graduate Theses and Dissertations

Multifunctional nanocomposites are promising for a variety of applications ranging from microwave devices to biomedicine. High demand exists for magnetically tunable nanocomposite materials. My thesis focuses on synthesis and characterization of novel nanomaterials such as polymer nanocomposites (PNCs) and multi-walled carbon nanotubes (MWCNTs) with magnetic nanoparticle (NP) fillers.

Magnetite (Fe3O4) and cobalt ferrite (CoFe2O4) NPs with controlled shape, size, and crystallinity were successfully synthesized and used as PNC fillers in a commercial polymer provided by the Rogers Corporation and poly(vinylidene fluoride). Magnetic and microwave experiments were conducted under frequencies of 1-6 GHz in the presence of …


Attitudes Toward Adult Education Among Adult Learners Without A High School Diploma Or Ged, Andrea Rose Bennett Nov 2016

Attitudes Toward Adult Education Among Adult Learners Without A High School Diploma Or Ged, Andrea Rose Bennett

USF Tampa Graduate Theses and Dissertations

The purpose of this study was to explore attitudes toward adult education among adult learners without a high school diploma or the General Educational Development (GED). In this study, adult learners without a high school diploma or GED completed the Attitudes Toward Adult Education Scale (AACES) and selected respondents volunteered to participate in a face-to-face interview in conjunction with the mixed methods section of the study. For this study, I used a 5-point Likert scale to measure the responses on the 22-item AACES survey.

Three hundred and fifty respondents participated in the study. Descriptive statistics and a three-way ANOVA revealed …


Advancements In Thermal Integrity Profiling Data Analysis, Kevin Russell Johnson Nov 2016

Advancements In Thermal Integrity Profiling Data Analysis, Kevin Russell Johnson

USF Tampa Graduate Theses and Dissertations

Thermal Integrity Profiling (TIP) is a relatively new non-destructive test method for evaluating the post-construction quality of drilled shafts. Therein anomalies in a shaft are indicated by variations in its thermal profile when measured during the curing stages of the concrete. A considerable benefit with this method is in the ability to detect anomalies both inside and outside the reinforcement cage, as well as provide a measure of lateral cage alignment. Similarly remarkable, early developments showed that the shape of a temperature profile (with depth) matched closely with the shape of the shaft, thus allowing for a straightforward interpretation of …


Optimal Demand Response Models With Energy Storage Systems In Smart Grids, Mohemmed Masooud Alhaider Nov 2016

Optimal Demand Response Models With Energy Storage Systems In Smart Grids, Mohemmed Masooud Alhaider

USF Tampa Graduate Theses and Dissertations

This research aims to develop solutions to relieve system stress conditions in electric grids. The approach adopted in this research is based on a new concept in the Smart Grid, namely, demand response optimization. A number of demand response programs with energy storage systems are designed to enable a community to achieve optimal demand side energy management.

The proposed models aim to improve the utilization of the demand side energy through load management programs including peak shaving, load shifting, and valley lling. First, a model is proposed to nd the optimal capacity of the battery energy storage system (BESS) to …


Towards Computational Human Behavior Modeling For Just-In-Time Adaptive Interventions, Tylar Murray Nov 2016

Towards Computational Human Behavior Modeling For Just-In-Time Adaptive Interventions, Tylar Murray

USF Tampa Graduate Theses and Dissertations

The advent of powerful wearable devices and smartphones has enabled a new generation of “in-the-wild” user studies, adaptive behavioral intervention strategies, and context measurement. Though numerous proof-of-concept studies continue to push the limitations of what a behavioral scientist can do with these technologies, there remains a major methodological roadblock separating behavioral theory and application. Avatar-user interaction theory, for example, is not well defined in its formulation, and thus guidelines for intervention designers depend on heuristic methods and designer intuition. Computational modeling has been slow to move into behavioral science in general, but a growing population of behavioral scientists recognize this …


Hospitable Climates: Representations Of The West Indies In Eighteenth-Century British Literature, Marisa Carmen Iglesias Nov 2016

Hospitable Climates: Representations Of The West Indies In Eighteenth-Century British Literature, Marisa Carmen Iglesias

USF Tampa Graduate Theses and Dissertations

British expansion to the West Indies in the eighteenth-century resulted in vast economic growth for the British Empire and a rise in literature set in the region. Examining the literature allows for an in-depth exploration of how the Caribbean has become associated as a place of relaxation and escape though its early history of colonialism is fraught with violence. My study builds on the understanding of the Caribbean region in the eighteenth-century and utilizes hospitality theory to articulate the role that cultural exchange and physical setting play in the texts and in the formation of national identity, both in the …


A Framework For Studying Meshfree Geometry And A Method For Explicit Boundary Determination, Joseph Bradley Alford Nov 2016

A Framework For Studying Meshfree Geometry And A Method For Explicit Boundary Determination, Joseph Bradley Alford

USF Tampa Graduate Theses and Dissertations

Patient-specific biomechanical analysis is an important tool used to understand the complex processes that occur in the body due to physical stimulation. Patient-specific models are generated by processing medical images; once an object from the image is identified via segmentation, a point cloud representation of the object is extracted. Generating an analysis suitable representation from the point cloud has traditionally required generating a finite element mesh, which often requires a well defined surface to accomplish. Point clouds lack a well defined geometry, meaning that the surface definition is incomplete at best. Point clouds that have been generated from images have …


Hydrolytic And Nonhydrolytic Sol-Gel Zirconia-, Titania-, And Niobia-Based Capillary Microextraction Coatings For The Preconcentration And Hplc Analysis Of Catecholamine Neurotransmitters And Phosphorylated Peptides, Abdullah Awadh Alhendal Nov 2016

Hydrolytic And Nonhydrolytic Sol-Gel Zirconia-, Titania-, And Niobia-Based Capillary Microextraction Coatings For The Preconcentration And Hplc Analysis Of Catecholamine Neurotransmitters And Phosphorylated Peptides, Abdullah Awadh Alhendal

USF Tampa Graduate Theses and Dissertations

Sample preparation is the most error-prone step in chemical analysis. A great deal of efforts has been made to develop efficient techniques and protocols for sample preparation to accomplish important goals such as miniaturization and implementation of green analytical methodologies. Solid-phase microextraction (SPME) has successfully eliminated the use of hazardous organic solvents in extraction sampling, sample preparation, preconcentration and sample introduction to the analytical instrument in an effective manner. Ensuring thermal- and solvent-instability of traditional SPME extraction phases represented one of their main drawbacks. This was solved by the introduction of sol-gel SPME phases characterized by enhanced thermal-, solvent-, and …


Surface Properties Of Titanium Dioxide And Its Structural Modifications By Reactions With Transition Metals, Sandamali Halpegamage Nov 2016

Surface Properties Of Titanium Dioxide And Its Structural Modifications By Reactions With Transition Metals, Sandamali Halpegamage

USF Tampa Graduate Theses and Dissertations

Surfaces of metal oxides play a vital role in many technologically important applications. The surfaces of titanium dioxide, in particular, show quite promising properties that can be utilized in solid-state gas sensing and photocatalysis applications. In the first part of this dissertation we investigate these properties of TiO2 surfaces through a vigorous surface scientific approach. In the second part, we investigate the possibilities of modifying the TiO2 surfaces by depositing multi-component transition metal oxide monolayers so that the properties of bare TiO2 surface can be influenced in a beneficial way. For instance, via formation of new surface …


Novel Magnetic Nanostructures For Enhanced Magnetic Hyperthermia Cancer Therapy, Zohreh Nemati Porshokouh Nov 2016

Novel Magnetic Nanostructures For Enhanced Magnetic Hyperthermia Cancer Therapy, Zohreh Nemati Porshokouh

USF Tampa Graduate Theses and Dissertations

In this dissertation, I present the results of a systematic study on novel multifunctional nanostructure systems for magnetic hyperthermia applications. All the samples have been synthesized, structurally/magnetically characterized, and tested for magnetic hyperthermia treatment at the Functional Materials Laboratory of the University South Florida. This work includes studies on four different systems: (i) Core/shell Fe/γ-Fe2O3 nanoparticles; (ii) Spherical and cubic exchange coupled FeO/Fe3O4 nanoparticles; (iii) Fe3O4 nano-octopods with different sizes; (iv) High aspect ratio FeCo nanowires and Fe3O4 nanorods.

In particular, we demonstrated the enhancement of the heating …


Self-Study Of A Supervisor Making Connections In An Integrated Instructional Third Space In Elementary Mathematics And Field Experience, Katie Arndt Nov 2016

Self-Study Of A Supervisor Making Connections In An Integrated Instructional Third Space In Elementary Mathematics And Field Experience, Katie Arndt

USF Tampa Graduate Theses and Dissertations

Too often teachers see mathematics as a culturally neutral subject. Teacher educators need to be aware of their own practice and how it impacts the facilitation of preservice teacher learning, in particular in relation to elementary mathematics and culturally responsive teaching. This qualitative self-study focused on understanding a teacher educator’s enactment of an espoused platform in an integrated instructional third space of an elementary field experience and an elementary mathematics methods course in relation to culturally responsive teaching and mathematics. The research questions guiding this self-study were: (1) In the context of the selfstudy, to what extent do I enact …


Expansion Of The Performance Capabilities Of The Usf Inhalation Challenge Chamber, Laura Riley Nov 2016

Expansion Of The Performance Capabilities Of The Usf Inhalation Challenge Chamber, Laura Riley

USF Tampa Graduate Theses and Dissertations

The purpose of this research was to evaluate the capability and performance of the University of South Florida’s (USF) Human Exposure Chamber (HEC) using aerosols in the thoracic range. The goals of this research were two-fold: to obtain an average particle size of 10 µm (thoracic-size range) inside the chamber during dust production and to test for evenness of dust concentration within the chamber. The USF HEC can be used for studies using gases and/or particulates. The chamber measurements are 4.16 ft x 2.67 ft x 6.75 ft, for a total volume of 75 ft3 or 2.13 m3 …


Miocene Contourite Deposition (Along-Slope) Near Desoto Canyon, Gulf Of Mexico: A Product Of An Enhanced Paleo-Loop Current, Shane Christopher Dunn Nov 2016

Miocene Contourite Deposition (Along-Slope) Near Desoto Canyon, Gulf Of Mexico: A Product Of An Enhanced Paleo-Loop Current, Shane Christopher Dunn

USF Tampa Graduate Theses and Dissertations

A Neogene contourite depositional system was identified and mapped along the DeSoto Slope in the northeastern Gulf of Mexico, U.S.A. A series of drift deposits comprising the larger contourite depositional system were interpreted from a 2-D industry seismic data set. The now subsurface drift deposits are adjacent to the anomalous seabed feature, the DeSoto Canyon, and these data suggest contourite deposition and ocean currents are in integral part of the canyon’s depositional history. The contourite depositional system is underlain by an extensive, middle Miocene aged, erosional unconformity formed by ocean currents. The timing of this erosional surface is in alignment …


Continuing The Career: An Oral History Of An Emeritus Professor, Kimberly Read Nov 2016

Continuing The Career: An Oral History Of An Emeritus Professor, Kimberly Read

USF Tampa Graduate Theses and Dissertations

The purpose of this study was to describe and explain the perspectives of a professor emeritus regarding his life experiences in the discipline of chemistry and in a career dedicated to research, service and teaching. Another purpose, interwoven within the perspective of this one individual, was to explore the potential influence a professor emeritus can have on his institution, and the impact the institution, its changing culture, and its shifting priorities may have on a member of the professoriate dedicated to this chosen career path. The research guiding questions for this study were: (a) What elements of this professor emeritus’ …


Perspectives Of Women In Orthopaedic Surgery On Leadership Development, Ann C. Joyce Nov 2016

Perspectives Of Women In Orthopaedic Surgery On Leadership Development, Ann C. Joyce

USF Tampa Graduate Theses and Dissertations

Over the past 50 years, the demographics of medical school graduates in the United States has changed dramatically with the number of women (47%) almost equaling the number of men in 2014 (AAMC, 2014). However, the Association of American Medical Colleges (2014) reports that orthopaedic surgery has the lowest proportion of female residents, instructors, assistants, associate, and full professors of all the sub-specialties and little has changed in the past several decades.

Due to the healthcare reform and the changing needs of our society, it is importance to recruit, retain, and promote women into leadership positions. The purpose of this …


Locomotion In Virtual Reality For Room Scale Tracked Areas, Evren Bozgeyikli Nov 2016

Locomotion In Virtual Reality For Room Scale Tracked Areas, Evren Bozgeyikli

USF Tampa Graduate Theses and Dissertations

In the recent years, virtual reality has been used as an effective tool for a wide range of areas such as training, rehabilitation, education and games. The affordability of the new generation headsets helped this medium to become more widespread. However, in order for virtual reality to become mainstream, more content that is specifically designed for this medium is needed. Since virtual reality is a different technology than the computer systems, different design principles may be required for these content for better user experience. One of the crucial components of virtual reality applications is locomotion, since the viewpoint of the …


Virtual Reality Serious Games For Individuals With Autism Spectrum Disorder: Design Considerations, Lal Bozgeyikli Nov 2016

Virtual Reality Serious Games For Individuals With Autism Spectrum Disorder: Design Considerations, Lal Bozgeyikli

USF Tampa Graduate Theses and Dissertations

Virtual reality has been a popular training tool for individuals with Autism Spectrum Disorder (ASD) in recent years. Although virtual reality was proven to be a promising tool for individuals with ASD by many previous studies, effects of virtual reality properties on user experience is still an unexplored area. More comparison studies and reliable data are needed to identify the benefits of different VR methods and properties, and leverage the future VR systems. In this dissertation, we explored effects of virtual reality properties on user experience of high functioning individuals with ASD with four different serious game experiments. The first …


An Early Paleogene Palynological Assemblage From The Sabrina Coast, East Antarctica: New Species And Implications For Depositional History, Catherine Davies Smith Nov 2016

An Early Paleogene Palynological Assemblage From The Sabrina Coast, East Antarctica: New Species And Implications For Depositional History, Catherine Davies Smith

USF Tampa Graduate Theses and Dissertations

Palynological analyses of 13 samples from two sediment cores retrieved from the Sabrina Coast, East Antarctica, provide the first information regarding the paleovegetation within the Aurora Subglacial Basin. The assemblages, hereafter referred to as the Sabrina Flora, are dominated by angiosperms, with complexes of Gambierina (G.) rudata and G. edwardsii representing 38–66% of the assemblage and an abundant and diverse Proteaceae component. The Sabrina Flora also includes Battenipollis sectilis, Forcipites sp. and Nothofagidites spp. (mostly belonging to the N. cf. rocaensis-flemingii complex), along with a few fern spores, including Laevigatosporites ovatus, a moderate presence of conifers, and …


An Ecosystem-Based Approach To Reef Fish Management In The Gulf Of Mexico, Michelle D. Masi Nov 2016

An Ecosystem-Based Approach To Reef Fish Management In The Gulf Of Mexico, Michelle D. Masi

USF Tampa Graduate Theses and Dissertations

Fisheries managers have the potential to significantly improve reef fish management in the Gulf of Mexico through the use of ecosystem-based approaches to fisheries management. Ecosystem-based approaches are needed to address the effects of fishing on trophodynamic interactions, to better account for ecosystem-scale processes in model projections, and to recognize the short and long-term biomass tradeoffs associated with making regulatory choices. My research was concentrated around three objectives: (1) characterizing the trophodynamic interactions between Gulf of Mexico fishes, in order to construct an invaluable tool (a Gulf of Mexico Atlantis model) to be used in ecological hypothesis testing and policy …


Predictors Of Associate's Degree Completion In Engineering And Engineering Technologies, Lynsey Reys-Nickel Nov 2016

Predictors Of Associate's Degree Completion In Engineering And Engineering Technologies, Lynsey Reys-Nickel

USF Tampa Graduate Theses and Dissertations

The purpose of this ex post facto study was to describe completers and non-completers of associate’s degree programs in engineering and engineering technologies and determine whether and to what extent completion in these programs is a function of selected student-related variables and institutional variables. Data from the 2004/2009 Beginning Postsecondary Students Longitudinal Study (BPS: 04/09) of associate’s degree completers and non-completers in engineering and engineering technologies were accessed and analyzed through PowerStats, a web-based data analysis tool from National Center for Education Statistics (NCES).

Descriptive data indicated that, proportionally, engineering and engineering technologies completers were mostly White, married, middle income, …


Efficiency Of An Unbalanced Design In Collecting Time To Event Data With Interval Censoring, Peiyao Cheng Nov 2016

Efficiency Of An Unbalanced Design In Collecting Time To Event Data With Interval Censoring, Peiyao Cheng

USF Tampa Graduate Theses and Dissertations

In longitudinal studies, the exact timing of an event often cannot be observed, and is usually detected at a subsequent visit, which is called interval censoring. Spacing of the visits is important when designing study with interval censored data. In a typical longitudinal study, the spacing of visits is usually the same across all subjects (balanced design). In this dissertation, I propose an unbalanced design: subjects at baseline are divided into a high risk group and a low risk group based on a risk factor, and the subjects in the high risk group are followed more frequently than those in …