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- Title
- A HOLISTIC USABILITY FRAMEWORK FOR DISTRIBUTED SIMULATION SYSTEMS.
- Creator
-
Dawson, Jeffrey, Rabelo, Luis, University of Central Florida
- Abstract / Description
-
This dissertation develops a holistic usability framework for distributed simulation systems (DSSs). The framework is developed considering relevant research in human-computer interaction, computer science, technical writing, engineering, management, and psychology. The methodology used consists of three steps: (1) framework development, (2) surveys of users to validate and refine the framework, and to determine attribute weights, and (3) application of the framework to two real-world systems...
Show moreThis dissertation develops a holistic usability framework for distributed simulation systems (DSSs). The framework is developed considering relevant research in human-computer interaction, computer science, technical writing, engineering, management, and psychology. The methodology used consists of three steps: (1) framework development, (2) surveys of users to validate and refine the framework, and to determine attribute weights, and (3) application of the framework to two real-world systems. The concept of a holistic usability framework for DSSs arose during a project to improve the usability of the Virtual Test Bed, a prototypical DSS, and the framework is partly a result of that project. In addition, DSSs at Ames Research Center were studied for additional insights. The framework has six dimensions: end user needs, end user interface(s), programming, installation, training, and documentation. The categories of participants in this study include managers, researchers, programmers, end users, trainers, and trainees. The first survey was used to obtain qualitative and quantitative data to validate and refine the framework. Attributes that failed the validation test were dropped from the framework. A second survey was used to obtain attribute weights. The refined framework was used to evaluate two existing DSSs, measuring their holistic usabilities. Ensuring that the needs of the variety of types of users who interact with the system during design, development, and use are met is important to launch a successful system. Adequate consideration of system usability along the several dimensions in the framework will not only ensure system success but also increase productivity, lower life cycle costs, and result in a more pleasurable working experience for people who work with the system.
Show less - Date Issued
- 2006
- Identifier
- CFE0001256, ucf:46906
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001256
- Title
- Volusia System For Empowering Teachers (VSET): Influence On Teacher Practice And Student Achievement.
- Creator
-
Sileo-Robinson, Lesley, Hewitt, Randall, Hopp, Carolyn, Vitale, Thomas, Taylor, Rosemarye, University of Central Florida
- Abstract / Description
-
This study provides an empirical analysis of the primary assumptions of a newly implemented teacher evaluation system, namely that the specific teaching practices evaluated are related to student achievement, and that teacher-directed professional growth plans effectively shape teacher practices in a particular domain. Results of the study are intended to inform the interpretation and the refinement of the Volusia System for Empowering Teachers (VSET), which aims to build capacity in the...
Show moreThis study provides an empirical analysis of the primary assumptions of a newly implemented teacher evaluation system, namely that the specific teaching practices evaluated are related to student achievement, and that teacher-directed professional growth plans effectively shape teacher practices in a particular domain. Results of the study are intended to inform the interpretation and the refinement of the Volusia System for Empowering Teachers (VSET), which aims to build capacity in the Volusia teacher work force and ultimately to improve student performance (School Board of Volusia County Team Volusia, Race to the Top application, 2011). This study focused on 14 pilot schools within one school district that implemented VSET as a new teacher evaluation system. The data used in this study were drawn from a multi-metric teacher assessment used in VSET and measures of student achievement. The VSET evaluation model consists of three metrics that are assigned according to the specific categories of a teacher. Two of the metrics, the professional growth plan rating and the educator observation rating are based on Charlotte Danielson's (")Framework for Teaching(") (Danielson, 2007). The third metric, the valued added score is a measure of the teacher's impact on student learning. The current study focused on determining if there was a correlation between teaching practice and student achievement and to what extent teaching practice was impacted by teacher self-selection of components for professional growth in the teacher evaluation model. The findings suggest that there is not a statistically significant and reliable relationship between the value added score and teacher practices across components, as assessed by VSET evaluators. Follow up analyses did, however, show that higher evaluator observation scores are associated with improved school grades, suggesting a relationship between teacher impact on student performance. The results support the assumption that the successful completion of the VSET professional development growth plan is associated with teacher's instructional practices in the identified component.
Show less - Date Issued
- 2013
- Identifier
- CFE0004938, ucf:49614
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004938
- Title
- Measuring the evolving Internet ecosystem with exchange points.
- Creator
-
Ahmad, Mohammad Zubair, Guha, Ratan, Bassiouni, Mostafa, Chatterjee, Mainak, Jha, Sumit, Goldiez, Brian, University of Central Florida
- Abstract / Description
-
The Internet ecosystem comprising of thousands of Autonomous Systems (ASes) now include Internet eXchange Points (IXPs) as another critical component in the infrastructure. Peering plays a significant part in driving the economic growth of ASes and is contributing to a variety of structural changes in the Internet. IXPs are a primary component of this peering ecosystem and are playing an increasing role not only in the topology evolution of the Internet but also inter-domain path routing. In...
Show moreThe Internet ecosystem comprising of thousands of Autonomous Systems (ASes) now include Internet eXchange Points (IXPs) as another critical component in the infrastructure. Peering plays a significant part in driving the economic growth of ASes and is contributing to a variety of structural changes in the Internet. IXPs are a primary component of this peering ecosystem and are playing an increasing role not only in the topology evolution of the Internet but also inter-domain path routing. In this dissertation we study and analyze the overall affects of peering and IXP infrastructure on the Internet. We observe IXP peering is enabling a quicker flattening of the Internet topology and leading to over-utilization of popular inter-AS links. Indiscriminate peering at these locations is leading to higher end-to-end path latencies for ASes peering at an exchange point, an effect magnified at the most popular worldwide IXPs. We first study the effects of recently discovered IXP links on the inter-AS routes using graph based approaches and find that it points towards the changing and flattening landscape in the evolution of the Internet's topology. We then study more IXP effects by using measurements to investigate the networks benefits of peering. We propose and implement a measurement framework which identifies default paths through IXPs and compares them with alternate paths isolating the IXP hop. Our system is running and recording default and alternate path latencies and made publicly available. We model the probability of an alternate path performing better than a default path through an IXP by identifying the underlying factors influencing the end-to end path latency. Our first-of-its-kind modeling study, which uses a combination of statistical and machine learning approaches, shows that path latencies depend on the popularity of the particular IXP, the size of the provider ASes of the networks peering at common locations and the relative position of the IXP hop along the path. An in-depth comparison of end-to-end path latencies reveal a significant percentage of alternate paths outperforming the default route through an IXP. This characteristic of higher path latencies is magnified in the popular continental exchanges as measured by us in a case study looking at the largest regional IXPs. We continue by studying another effect of peering which has numerous applications in overlay routing, Triangle Inequality Violations (TIVs). These TIVs in the Internet delay space are created due to peering and we compare their essential characteristics with overlay paths such as detour routes. They are identified and analyzed from existing measurement datasets but on a scale not carried out earlier. This implementation exhibits the effectiveness of GPUs in analyzing big data sets while the TIVs studied show that the a set of common inter-AS links create these TIVs. This result provides a new insight about the development of TIVs by analyzing a very large data set using GPGPUs.Overall our work presents numerous insights into the inner workings of the Internet's peering ecosystem. Our measurements show the effects of exchange points on the evolving Internet and exhibits their importance to Internet routing.
Show less - Date Issued
- 2013
- Identifier
- CFE0004802, ucf:49744
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004802
- Title
- AMERICAN AGRIBUSINESS AND BIOTECHNOLOGY: A NEW ERA OF FARMING.
- Creator
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Ryan, Nicole M, Sadri, Houman, University of Central Florida
- Abstract / Description
-
In the past fifty years there has been an incredible amount of change made to the agrarian system of the United States. New discoveries in the realm of biotechnology led to the adoption of genetically modified organisms (GMOs) in agriculture, and transformed the industry. Due to regulatory policies set during the nineteen-eighties this technology was able to benefit from widespread commercialization. Today, we see the effects of this approach and are entering into a highly volatile political...
Show moreIn the past fifty years there has been an incredible amount of change made to the agrarian system of the United States. New discoveries in the realm of biotechnology led to the adoption of genetically modified organisms (GMOs) in agriculture, and transformed the industry. Due to regulatory policies set during the nineteen-eighties this technology was able to benefit from widespread commercialization. Today, we see the effects of this approach and are entering into a highly volatile political climate in regard to GMOs. This paper aims to provide an analysis of the regulatory system in place and the discrepancies that exist in US policy. The factors evaluated through this thesis include the current US regulatory approach, advancements in biotechnology, and a comparative perspective on US and EU systems. In each of these reviews it is also relevant to mention consumer opinion on GMOs and the role of interest groups. It is important for every American consumer to understand the politics and technology behind their meals. Through the analysis of recent judicial decisions and the enactment of new laws this thesis explains how the use of GMOs in agriculture is causing an unprecedented change to the political structures in place.
Show less - Date Issued
- 2016
- Identifier
- CFH2000035, ucf:45586
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000035
- Title
- A Framework for Quantifying Sustainability of Lean Implementation in Healthcare Organizations.
- Creator
-
Bahaitham, Haitham, Elshennawy, Ahmad, Mollaghasemi, Mansooreh, Lee, Gene, Uddin, Nizam, Furterer, Sandra, University of Central Florida
- Abstract / Description
-
Due to the remarkable positive effect of lean adoption in various firms in the manufacturing sector, it has been adopted by several organizations within the healthcare industry. Although the rate of adopting lean by hospitals in the developed countries is slower than it should be, it proved to be effective in helping healthcare organizations maintain or even improve their quality of care while containing their related costs. However, such adoption did not take place until the beginning of the...
Show moreDue to the remarkable positive effect of lean adoption in various firms in the manufacturing sector, it has been adopted by several organizations within the healthcare industry. Although the rate of adopting lean by hospitals in the developed countries is slower than it should be, it proved to be effective in helping healthcare organizations maintain or even improve their quality of care while containing their related costs. However, such adoption did not take place until the beginning of the new millennium. And with such adoption, it has been accompanied with major challenges related to proper lean implementation, sustainability of achieved levels of performance, and staff engagement in infinite cycles of continuous improvement towards perfection. Thus, the purpose of this study is to develop a framework that helps healthcare organizations quantify their experience with lean. Such quantification is obtained by measuring the agreement level of hospital staff members about the degree of adopting two sets of critical factors of successful lean implementation within their hospital. These two sets of factors are classified as process factors and organizational factors. The proposed framework has been validated by determining the sustainability level of lean implementation within one of U.S. hospitals in the State of Florida. The developed framework provides a balanced assessment of both process and organizational factors essential for achieving sustainable levels of lean implementation. In order to accommodate for the observed variation in lean adoption in hospitals, individual hospital departments are considered the (")analysis units(") of the developed framework. In order to quantify the implementation status of lean within a hospital department, a survey-based lean sustainability assessment tool has been developed based on the defined sets of factors. The sustainability level of lean implementation of a hospital can be obtained by combining various responses of its surveyed departments. The developed framework is the first that addresses both process and organizational factors of sustainable lean implementation in a balanced manner while fulfilling the assessment needs of all healthcare organizations regardless of their current level of lean adoption. In addition, utilizing the framework within a hospital enhances employee involvement and respect for employee which are essential for sustainable lean implementation. Finally, the developed framework provides healthcare supervising authorities (i.e. ministries of health or corporate offices of hospitals' groups) a macro-level benchmarking view regarding the progress of their hospitals towards implementing sustainable levels of lean.
Show less - Date Issued
- 2011
- Identifier
- CFE0004086, ucf:49140
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004086
- Title
- K-12 Transition Framework for Students with Disabilties.
- Creator
-
Delaney, Clydia, Hopp, Carolyn, Reyes, Maria, Little, Mary, Robertson, Shelby, University of Central Florida
- Abstract / Description
-
The problem of practice that this dissertation addressed was the post-secondary transition of students with disabilities, which has garnered national and international attention for decades. This dissertation was completed to inform the educational community regarding the potential for improvement in the post-secondary transition process of students with disabilities. Multiple factors were examined related to helping students with disabilities develop appropriate skills to transition through...
Show moreThe problem of practice that this dissertation addressed was the post-secondary transition of students with disabilities, which has garnered national and international attention for decades. This dissertation was completed to inform the educational community regarding the potential for improvement in the post-secondary transition process of students with disabilities. Multiple factors were examined related to helping students with disabilities develop appropriate skills to transition through school into personally successful, post-secondary activities and environments.A pilot study was conducted to inform a potential transition framework. Invitations to participate in an anonymous survey were sent to 741 teachers in the district via email. The survey, conducted in a small North Florida School District, had 289 nine participants, but not all participants were targeted to respond to every question. In addition to the quantitative items, the survey included several open response questions, which were coded and themed to inform the framework and specific concerns of the Director of Exceptional Student Services.The data from the pilot study were used to develop the K (-) 12 Transition Framework, which included levels of knowledge development from kindergarten through high school. Introducing students with disabilities to post-secondary transition concepts in the elementary grades supports the construction of a prior knowledge base at the elementary grade level. The prior knowledge base will be enhanced potential knowledge growth regarding opportunities, education and careers. This will translate into the successful transition of students with disabilities into personally successful, post-secondary activities and environments.
Show less - Date Issued
- 2016
- Identifier
- CFE0006292, ucf:51582
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006292
- Title
- Faculty Professional Development for Improving Hybrid Course Success.
- Creator
-
Lawhon, Jennifer, Hopp, Carolyn, Vitale, Thomas, Hines, Rebecca, Phelps, Julie, University of Central Florida
- Abstract / Description
-
The purpose of this Dissertation in Practice was to investigate the inconsistent success rates in hybrid courses at a Florida college. Results from a pilot study and faculty survey revealed a need for a training program specific to hybrid instructors. The researchers created a training program composed of a framework and a professional development course, designed to promote consistency in how instructors create and implement their hybrid courses. The framework consists of six research-based...
Show moreThe purpose of this Dissertation in Practice was to investigate the inconsistent success rates in hybrid courses at a Florida college. Results from a pilot study and faculty survey revealed a need for a training program specific to hybrid instructors. The researchers created a training program composed of a framework and a professional development course, designed to promote consistency in how instructors create and implement their hybrid courses. The framework consists of six research-based standards which aided in the creation of six learning modules for the professional development course. These modules were: course alignment, face-to-face active learning, online resources, formative feedback, assessment guidelines, and course structure. A focus group of faculty members who have taught hybrid courses at the college was used to review the course and framework to assess whether any modifications are required. The focus group discussion revealed that all six elements of the framework are essential to the success of a hybrid course design. The focus group also suggested changes and revisions to the professional development course which should be addressed prior to rolling out the course college-wide.
Show less - Date Issued
- 2017
- Identifier
- CFE0006757, ucf:51861
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006757
- Title
- Faculty Professional Development for Improving Hybrid Course Success.
- Creator
-
Saxman, Amanda, Hopp, Carolyn, Vitale, Thomas, Hines, Rebecca, Phelps, Julie, University of Central Florida
- Abstract / Description
-
The purpose of this Dissertation in Practice was to investigate the inconsistent success rates in hybrid courses at a Florida college. Results from a pilot study and faculty survey revealed a need for a training program specific to hybrid instructors. The researchers created a training program composed of a framework and a professional development course, designed to promote consistency in how instructors create and implement their hybrid courses. The framework consists of six research-based...
Show moreThe purpose of this Dissertation in Practice was to investigate the inconsistent success rates in hybrid courses at a Florida college. Results from a pilot study and faculty survey revealed a need for a training program specific to hybrid instructors. The researchers created a training program composed of a framework and a professional development course, designed to promote consistency in how instructors create and implement their hybrid courses. The framework consists of six research-based standards which aided in the creation of six learning modules for the professional development course. These modules were: course alignment, face-to-face active learning, online resources, formative feedback, assessment guidelines, and course structure. A focus group of faculty members who have taught hybrid courses at the college was used to review the course and framework to assess whether any modifications are required. The focus group discussion revealed that all six elements of the framework are essential to the success of a hybrid course design. The focus group also suggested changes and revisions to the professional development course which should be addressed prior to rolling out the course college-wide.
Show less - Date Issued
- 2017
- Identifier
- CFE0006791, ucf:51819
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006791
- Title
- Intelligent Selection Techniques For Virtual Environments.
- Creator
-
Cashion, Jeffrey, Laviola II, Joseph, Bassiouni, Mostafa, Hughes, Charles, Bowman, Doug, University of Central Florida
- Abstract / Description
-
Selection in 3D games and simulations is a well-studied problem. Many techniques have been created to address many of the typical scenarios a user could experience. For any single scenario with consistent conditions, there is likely a technique which is well suited. If there isn't, then there is an opportunity for one to be created to best suit the expected conditions of that new scenario. It is critical that the user be given an appropriate technique to interact with their environment....
Show moreSelection in 3D games and simulations is a well-studied problem. Many techniques have been created to address many of the typical scenarios a user could experience. For any single scenario with consistent conditions, there is likely a technique which is well suited. If there isn't, then there is an opportunity for one to be created to best suit the expected conditions of that new scenario. It is critical that the user be given an appropriate technique to interact with their environment. Without it, the entire experience is at risk of becoming burdensome and not enjoyable.With all of the different possible scenarios, it can become problematic when two or more are part of the same program. If they are put closely together, or even intertwined, then the developer is often forced to pick a single technique that works so-so in both, but is likely not optimal for either, or maybe optimal in just one of them. In this case, the user is left to perform selections with a technique that is lacking in one way or another, which can increase errors and frustration.In our research, we have outlined different selection scenarios, all of which were classified by their level of object density (number of objects in scene) and object velocity. We then performed an initial study on how it impacts performance of various selection techniques, including a new selection technique that we developed just for this test, called Expand. Our results showed, among other things, that a standard Raycast technique works well in slow moving and sparse environments, while revealing that our new Expand technique works well in denser environments.With the results from our first study, we sought to develop something that would bridge the gap in performance between those selection techniques tested. Our idea was a framework that could harvest several different selection techniques and determine which was the most optimal at any time. Each selection technique would report how effective it was, given the provided scenario conditions. The framework was responsible for activating the appropriate selection technique when the user made a selection attempt. With this framework in hand, we performed two additional user studies to determine how effective it could be in actual use, and to identify its strengths and weaknesses. Each study compared several selection techniques individually against the framework which utilized them collectively, picking the most suitable. Again, the same scenarios from our first study were reused. From these studies, we gained a deeper understanding of the many challenges associated with automatic selection technique determination. The results from these two studies showed that transitioning between techniques was potentially viable, but rife with design challenges that made its optimization quite difficult.In an effort to sidestep some of the issues surrounding the switching of discrete techniques, we sought to attack the problem from the other direction, and make a single technique act similarly to two techniques, adjusting dynamically to conditions. We performed a user study to analyze the performance of such a technique, with promising results. While the qualitative differences were small, the user feedback did indicate that users preferred this technique over the others, which were static in nature.Finally, we sought to gain a deeper understanding of existing selection techniques that were dynamic in nature, and study how they were designed, and how they could be improved. We scrutinized the attributes of each technique that were already being adjusted dynamically or that could be adjusted and innovated new ways in which the technique could be improved upon. Within this analysis, we also gave thought to how each technique could be best integrated into the Auto-Select framework we proposed earlier. This overall analysis of the latest selection techniques left us with an array of new variants that warrant being created and tested against their existing versions.Our overall research goal was to perform an analysis of selection techniques that intelligently adapt to their environment. We believe that we achieved this by performing several iterative development cycles, including user studies and ultimately leading to innovation in the field of selection. We conclude our research with yet more questions left to be answered. We intend to pursue further research regarding some of these questions, as time permits.
Show less - Date Issued
- 2014
- Identifier
- CFE0005469, ucf:50381
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005469
- Title
- FRAMEWORK FOR COST MODELING A SUPPLY CHAIN.
- Creator
-
Yousef, Nabeel, Sepulveda, Jose, University of Central Florida
- Abstract / Description
-
Researchers are interested in value chain analysis to identify the different opportunities for cost savings. The literature have been narrow in scope and addressed specific problems; however none has addressed the need for a general framework that can be used as a standard template in the supply chain cost management and optimization, though Dekker and Goor (2000) said that the goal was to develop a model that would allow direct comparison of specific activities between firms, such as...
Show moreResearchers are interested in value chain analysis to identify the different opportunities for cost savings. The literature have been narrow in scope and addressed specific problems; however none has addressed the need for a general framework that can be used as a standard template in the supply chain cost management and optimization, though Dekker and Goor (2000) said that the goal was to develop a model that would allow direct comparison of specific activities between firms, such as warehousing activities costs. There was no indication in the literature of a cost model that can identify all costs and cost drivers through the supply chain. Some firms built models to analyze the effect of changes in activities but only with limited activities such as logistics. The purpose of this research is to create a general framework that can express the cost data for the partners of the supply chain in similar terms. The framework will layout the common activities identified within the firm and the relationship of these activities between the partners of the supply chain, and the framework will identify the effect of changes in activities on other partners within the supply chain. Cost information will help in making decisions about pricing, outsourcing, capital expenditures, and operational efficiency. The framework will be able to track cost through the chain, which will improve the flexibility of the supply chain to respond to rapidly changing technology. The framework will help in developing product strategy paradigms that encompass the dynamics of the market, in particular with respect to the technology adoption lifecycle.
Show less - Date Issued
- 2006
- Identifier
- CFE0001038, ucf:46821
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001038
- Title
- Social Media as a Healthcare Tool: Case Study Analysis of Factors Influencing Pediatric Clinicians' Behavioral Intent to Adopt Social Media for Patient Communication and Engagement.
- Creator
-
Mustonen, Rachel, Hou, Su-I, Malvey, Donna, Gurupur, Varadraj, Wisniewski, Pamela, University of Central Florida
- Abstract / Description
-
Social media aids communication among users worldwide. However, a notable gap exist among social media users, healthcare professionals utilizing social media in the work place. While the concept of harnessing social media as a professional tool is not novel, healthcare professionals have yet to embrace the practice as standard workflow. This study identifies factors influencing clinicians' behavioral intent to adopt social media for patient engagement and communication. A new framework, the...
Show moreSocial media aids communication among users worldwide. However, a notable gap exist among social media users, healthcare professionals utilizing social media in the work place. While the concept of harnessing social media as a professional tool is not novel, healthcare professionals have yet to embrace the practice as standard workflow. This study identifies factors influencing clinicians' behavioral intent to adopt social media for patient engagement and communication. A new framework, the Healthcare Social Media Adoption Framework (HSMA), guided this mixed-method approach to assess 7 factors identified by theory and literature as adoption influencers. A custom, web-based survey collected data from 60 full-time, pediatric clinicians (47 quantitative) at the case institution (a pediatric hospital). Additionally, individual interviews of 6 participants provided their prospective on using social media for patient communications and engagement. Results: Privacy concerns were the only statically significant factor; with an inverse relationship to positive adoption intent, indicating higher privacy concerns influence lower behavioral intent to adopt social media for patient engagement and communication. The qualitative analysis revealed privacy concerns encompass two themes, personal privacy for patient and providers (boundaries), and cybersecurity. The qualitative inputs also uncovered perceived unprofessionalism as a new factor influencing clinician adoption. The implications for these findings indicate a need for both healthcare organizations and healthcare regulators to establish cyber-security defenses for security and use protocols for privacy to aid the diffusion and adoption acceptance of social media use by pediatric healthcare professionals. This research has contributed in four areas: 1) fill a knowledge gap by identifying new factors that influence the behavioral intent of pediatric clinicians to adopt social media; 2) confirm/reject behavioral intent influences found in the literature; 3) formulated a new HSMA framework that measures functional, cognitive, and social aspects of social media adoption; and 4) prioritizes policies and global standard focus.
Show less - Date Issued
- 2018
- Identifier
- CFE0007062, ucf:51998
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007062
- Title
- A Generic Framework For Multi-Method Modeling and Simulation of Complex Systems Using Discrete Event, System Dynamics and Agent Based Approaches.
- Creator
-
Mykoniatis, Konstantinos, Karwowski, Waldemar, Kincaid, John, Xanthopoulos, Petros, Akbas, Ilhan, University of Central Florida
- Abstract / Description
-
Decisions about Modeling and Simulation (M(&)S) of Complex Systems (CS) need to be evaluated prior to implementation. Discrete Event (DE), System Dynamics (SD), and Agent Based (AB) are three different M(&)S approaches widely applied to enhance decision-making of complex systems. However, single type M(&)S approaches can face serious challenges in representing the overall multidimensional nature of CS and may result in the design of oversimplified models excluding important factors....
Show moreDecisions about Modeling and Simulation (M(&)S) of Complex Systems (CS) need to be evaluated prior to implementation. Discrete Event (DE), System Dynamics (SD), and Agent Based (AB) are three different M(&)S approaches widely applied to enhance decision-making of complex systems. However, single type M(&)S approaches can face serious challenges in representing the overall multidimensional nature of CS and may result in the design of oversimplified models excluding important factors. Conceptual frameworks are necessary to offer useful guidance for combining and/or integrating different M(&)S approaches. Although several hybrid M(&)S frameworks have been described and are currently deployed, there is limited guidance on when, why and how to combine, and/or integrate DE, SD, and AB approaches. The existing hybrid frameworks focus more on how to deal with specific problems rather than to provide a generic way of applicability to various problem situations.The main aim of this research is to develop a generic framework for Multi-Method Modeling and Simulation of CS, which provides a practical guideline to integrated deployment or combination of DE, SD, and AB M(&)S methods. The key contributions of this dissertation include: (1) a meta-analysis literature review that identifies criteria and generic types of interaction relationships that are served as a basis for the development of a multi-method modeling and simulation framework; (2) a methodology and a framework that guide the user through the development of multi-method simulation models to solve CS problems; (3) an algorithm that recommends appropriate M(&)S method(s) based on the user selected criteria for user defined objective(s); (4) the implementation and evaluation of multi method simulation models based on the framework's recommendation in diverse domains; and (5) the comparison of multi-method simulation models created by following the multi-method modeling and simulation framework.It is anticipated that this research will inspire and motivate students, researchers, practitioners and decision makers engaged in M(&)S to become aware of the benefits of the cross-fertilization of the three key M(&)S methods.
Show less - Date Issued
- 2015
- Identifier
- CFE0005980, ucf:50762
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005980
- Title
- TryOpenJML - A Verily based web application for learning about the Java Modeling Language.
- Creator
-
Deshpande, Tushar, Leavens, Gary, Turgut, Damla, Dechev, Damian, University of Central Florida
- Abstract / Description
-
This thesis has a two-fold purpose. On the one hand, the web applications are an important part of life. On a day to day basis, from managing our heath care choices to banking, to connecting to a friend, almost everything is done through a web application. Development of these applications is also a very trend-driven domain. Numerous web frameworks are available today, but almost none has been created taking reliability into consideration. With the combination of application construction...
Show moreThis thesis has a two-fold purpose. On the one hand, the web applications are an important part of life. On a day to day basis, from managing our heath care choices to banking, to connecting to a friend, almost everything is done through a web application. Development of these applications is also a very trend-driven domain. Numerous web frameworks are available today, but almost none has been created taking reliability into consideration. With the combination of application construction recipes and static analysis, the Verily framework was created to build more reliable web applications.On the other hand, the goal of the Java Modeling Language (JML) has to be conveyed to the world. It is a language that can go hand in hand with existing code, having a wide range of tools that help build practical and effective designs. There are many tools available for JML: jmldoc for web pages, jmlunit for unit tests, jmlc for class files, etc. I will be using the tools for Runtime Assertion Checking (RAC) and Extended Static Checking (ESC). These checks warn about the possible runtime exceptions and assertion violations. The benefits of JML assert statements over Java assertions are that they support all JML features.The question that I am concerned with, in this thesis, is how the Verily Framework can contribute to the domain of web application development. Keeping this question in mind, my objective is to create a tutorial which will aid in learning about JML. The tutorial will let the potential users read and write JML specifications and use JML tools, explain basic JML semantics, and let them know where to go for help if they need more details.
Show less - Date Issued
- 2016
- Identifier
- CFE0006293, ucf:51614
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006293
- Title
- Scene Understanding for Real Time Processing of Queries over Big Data Streaming Video.
- Creator
-
Aved, Alexander, Hua, Kien, Foroosh, Hassan, Zou, Changchun, Ni, Liqiang, University of Central Florida
- Abstract / Description
-
With heightened security concerns across the globe and the increasing need to monitor, preserve and protect infrastructure and public spaces to ensure proper operation, quality assurance and safety, numerous video cameras have been deployed. Accordingly, they also need to be monitored effectively and efficiently. However, relying on human operators to constantly monitor all the video streams is not scalable or cost effective. Humans can become subjective, fatigued, even exhibit bias and it is...
Show moreWith heightened security concerns across the globe and the increasing need to monitor, preserve and protect infrastructure and public spaces to ensure proper operation, quality assurance and safety, numerous video cameras have been deployed. Accordingly, they also need to be monitored effectively and efficiently. However, relying on human operators to constantly monitor all the video streams is not scalable or cost effective. Humans can become subjective, fatigued, even exhibit bias and it is difficult to maintain high levels of vigilance when capturing, searching and recognizing events that occur infrequently or in isolation.These limitations are addressed in the Live Video Database Management System (LVDBMS), a framework for managing and processing live motion imagery data. It enables rapid development of video surveillance software much like traditional database applications are developed today. Such developed video stream processing applications and ad hoc queries are able to "reuse" advanced image processing techniques that have been developed. This results in lower software development and maintenance costs. Furthermore, the LVDBMS can be intensively tested to ensure consistent quality across all associated video database applications. Its intrinsic privacy framework facilitates a formalized approach to the specification and enforcement of verifiable privacy policies. This is an important step towards enabling a general privacy certification for video surveillance systems by leveraging a standardized privacy specification language.With the potential to impact many important fields ranging from security and assembly line monitoring to wildlife studies and the environment, the broader impact of this work is clear. The privacy framework protects the general public from abusive use of surveillance technology; success in addressing the (")trust(") issue will enable many new surveillance-related applications. Although this research focuses on video surveillance, the proposed framework has the potential to support many video-based analytical applications.
Show less - Date Issued
- 2013
- Identifier
- CFE0004648, ucf:49900
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004648
- Title
- PROPOSED BIOMEDICAL APPLICATIONS OF ZIRCONIUM-BASED METAL-ORGANIC FRAMEWORKS AS DRUG DELIVERY SYSTEMS.
- Creator
-
Perry-Mills, Ariel Margaret, Uribe-Romo, Fernando, Borgon, Robert, University of Central Florida
- Abstract / Description
-
Metal-organic frameworks (MOFs) are a class of highly crystalline nanoporous materials that self-assemble from inorganic metal oxide clusters and multitopic organic linkers. MOFs can be altered in terms of the types of metals and structures of organic linkers used, allowing for a high degree of customization and manipulation of the synergistic chemical or physical properties that arise from the precise coordination of their molecular components, including exceptionally large surface area and...
Show moreMetal-organic frameworks (MOFs) are a class of highly crystalline nanoporous materials that self-assemble from inorganic metal oxide clusters and multitopic organic linkers. MOFs can be altered in terms of the types of metals and structures of organic linkers used, allowing for a high degree of customization and manipulation of the synergistic chemical or physical properties that arise from the precise coordination of their molecular components, including exceptionally large surface area and pore size. Zirconium-based MOFs, called UiOs in honor of their conception at the University of Oslo, also show remarkable chemical stability in both acidic and basic environments, making them excellent candidates for biomedical applications as drug delivery systems, where they can either function as molecular cargo ships, with drugs packed into their pores, or as controlled release systems, in which drug molecules are directly attached to their ligands for precise delivery. The objective of this work is to prepare water-stable MOFs whose linkers are decorated with functional groups that have potential compatibility in drug delivery systems and to explore the efficacy of certain synthesis conditions in terms of the crystallinity of the MOF product. Thus, we hope to establish a basis for the ligation of anticancer drugs and fluorescent tags to MOFs for their controlled release at a specified location within the body. These targeted release mechanisms represent new therapeutic possibilities in terms of cancer treatment as their specificity would mitigate damage to healthy tissues, thereby addressing one of the greatest weakness of present treatment options.
Show less - Date Issued
- 2019
- Identifier
- CFH2000531, ucf:45634
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000531
- Title
- Streamflow prediction in ungauged basins located within data-scarce regions.
- Creator
-
Alipour, Mohammadhossein, Kibler, Kelly, Wang, Dingbao, Mayo, Talea, Emrich, Christopher, University of Central Florida
- Abstract / Description
-
Preservation and or restoration of riverine ecosystem requires quantification of alterations inflicted by water resources development projects. Long records of streamflow data are the first piece of information required in order to enable this analysis. Ungauged catchments located within data-scarce regions lack long records of streamflow data. In this dissertation, a multi-objective framework named Streamflow Prediction under Extreme Data-scarcity (SPED) is proposed for streamflow prediction...
Show morePreservation and or restoration of riverine ecosystem requires quantification of alterations inflicted by water resources development projects. Long records of streamflow data are the first piece of information required in order to enable this analysis. Ungauged catchments located within data-scarce regions lack long records of streamflow data. In this dissertation, a multi-objective framework named Streamflow Prediction under Extreme Data-scarcity (SPED) is proposed for streamflow prediction in ungauged catchments located within large-scale regions of minimal hydrometeorologic observation. Multi-objective nature of SPED allows for balancing runoff efficiency with selection of parameter values that resemble catchment physical characteristics. Uncertain and low-resolution information are incorporated in SPED as soft data along with sparse observations. SPED application in two catchments in southwestern China indicates high runoff efficiency for predictions and good estimation of soil moisture capacity in the catchments. SPED is then slightly modified and tested more comprehensively by application to six catchments with diverse hydroclimatic conditions. SPED performance proves satisfactory where traditional flow prediction approaches fail. SPED also proves comparable or even better than data-intensive approaches. Utility of SPED versus a simpler catchment similarity model for the study of flow regime alteration is pursued next by streamflow prediction in 32 rivers in southwestern China. The results indicate that diversion adversely alters the flow regime of the rivers while direction and pattern of change remain the same regardless of the flow prediction method of choice. However, the results based on SPED consistently indicate more substantial alterations to the flow regime of the rivers after diversion. Finally, the value added by a limited number of streamflow observations to improvement of predictions in an ungauged catchment located within a data-scarce region is studied. The large number of test scenarios indicate that there may be very few near-universal schemes to improve flow predictions in such catchments.
Show less - Date Issued
- 2019
- Identifier
- CFE0007426, ucf:52713
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007426
- Title
- Synthetic Design and Characterization of Polycyclic Aromatic Compounds in Molecular and Extended System.
- Creator
-
Pour, Gavin, Belfield, Kevin, Frazer, Andrew, Elsheimer, Seth, University of Central Florida
- Abstract / Description
-
The work presented herein focuses on the synthesis and characterization of polycyclic aromatic compounds for a wide variety of toxicological, analytical, and electronic applications. First, the modular synthesis of 12 dibenzo- and naphtho- fluoranthene polycyclic aromatic hydrocarbons (PAHs) via a Pd-catalyzed five-membered ring closing procedure is discussed. By understanding the various modes through which the Pd migrates during transformation, structural rearrangements were bypassed,...
Show moreThe work presented herein focuses on the synthesis and characterization of polycyclic aromatic compounds for a wide variety of toxicological, analytical, and electronic applications. First, the modular synthesis of 12 dibenzo- and naphtho- fluoranthene polycyclic aromatic hydrocarbons (PAHs) via a Pd-catalyzed five-membered ring closing procedure is discussed. By understanding the various modes through which the Pd migrates during transformation, structural rearrangements were bypassed, obtaining regioselectivity through various redesigns in the synthetic route. Each compound in the serious was rigorously characterized via 1D/2D NMR, absorption and emission spectroscopy as well as cyclic voltammetry, which shows vast differences due to small structural changes between these constitutional isomers. Next, a series of polyphenylated organic ligands for zirconium metal organic frameworks is presented as materials for post-synthetic Scholl cyclodehydrogenation. Lastly, a series of organic linkers featuring covalently anchored redox-active pendants is explored for tuneable redox activity in Zr-based metal-organic frameworks. Thin-films were grown onto fluorine-doped tin-oxide glass electrodes and analyzed by cyclic voltammetry. This is the first reported pre-synthetic incorporation of covalently-bound ferrocenyl pendants into such a system. By attenuating the proportions of redox active and inactive links the oxidative peak currents could be tuned. This body of work represents a contribution toward the practical design and synthesis of polycyclic aromatic for a wide variety of analytical and electrochemical applications.
Show less - Date Issued
- 2019
- Identifier
- CFE0007512, ucf:52647
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007512
- Title
- Risk Perceptions of Climate Change in International Environmental Negotiations.
- Creator
-
Dellert, Christine, Jacques, Peter, Knox, Claire, Hamann, Kerstin, University of Central Florida
- Abstract / Description
-
Climate change poses an unprecedented risk to global human security and future generations. Yet actions to mitigate or adapt to the changing climate system vary greatly among countries and their constituencies. Despite mounting evidence detailing the economic, social, and ecological risks of climate change, many scholars agree that the greatest threats associated with climate change involve delaying or ignoring necessary action. Using theorizing of (")risk society(") from Ulrich Beck and...
Show moreClimate change poses an unprecedented risk to global human security and future generations. Yet actions to mitigate or adapt to the changing climate system vary greatly among countries and their constituencies. Despite mounting evidence detailing the economic, social, and ecological risks of climate change, many scholars agree that the greatest threats associated with climate change involve delaying or ignoring necessary action. Using theorizing of (")risk society(") from Ulrich Beck and others, this thesis examines how countries, environmental non-governmental organizations (NGOs), and business interests construct the risk of climate change and how their respective discourses conflict in international environmental negotiations. This research uses computer-assisted qualitative data analysis to explore statements submitted by each of these constituencies to the sixteenth Conference of the Parties (COP) for the United Nations Framework Convention on Climate Change (UNFCCC) in 2010. Analysis of these texts identifies climate change discourse as crisis or opportunity, in addition to discourses of development, environmentalism, and rights or responsibilities to provide us a better understanding of how we perceive and respond to ecological risk.
Show less - Date Issued
- 2015
- Identifier
- CFE0005602, ucf:50252
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005602
- Title
- A modeling framework of brittle and ductile fractures coexistence in composites.
- Creator
-
Qiao, Yangyang, Bai, Yuanli, Gou, Jihua, Kassab, Alain, Gordon, Ali, An, Linan, University of Central Florida
- Abstract / Description
-
In order to reduce the weight of automobiles and aircrafts, lightweight materials, such as aluminum alloy, advanced high strength steel, composite materials, are widely used to replace the traditional materials like mild steel. Composite materials are complicated in material mechanical properties and less investigated compared to metallic materials. Engineering composites can be categorized into polymer matrix composites (PMCs), metal matrix composites (MMCs) and ceramic matrix composites ...
Show moreIn order to reduce the weight of automobiles and aircrafts, lightweight materials, such as aluminum alloy, advanced high strength steel, composite materials, are widely used to replace the traditional materials like mild steel. Composite materials are complicated in material mechanical properties and less investigated compared to metallic materials. Engineering composites can be categorized into polymer matrix composites (PMCs), metal matrix composites (MMCs) and ceramic matrix composites (CMCs) according to their matrix materials.A set of mechanical experiments ranging from micro scale (single fiber composite and thin film composite) to macro scale (PMCs and MMCs) were conducted to fully understand the material behavior of composite materials. Loading conditions investigated includes uniaxial tension, three-point bending, uniaxial compression, simple shear, tension combined with shear, and compression combined with shear.For single fiber composite and thin-film composite, details of each composition are modelled. For the PMCs and MMCs which have plenty of reinforcements like fibers and particles, the details of the composition of structures cannot be modelled due to the current limitations of computing power. A mechanics framework of composite materials including elasticity, plasticity, failure initiation and post failure softening is proposed and applied to two types of composite materials.Uniaxial tension loading is applied to several single fiber composites and thin film composites. A surprising phenomenon, controllable and sequential fragmentation of the brittle fiber to produce uniformly sized rods along meters of polymer cladding, rather than the expected random or chaotic fragmentation, is observed with a necking propagation process. A combination of necking propagation model, fiber cracking model and interfacial model are proposed and applied to the finite element simulations. Good predictions of necking propagation and uniform fragmentation phenomenon are achieved. This modeling method of the micro-scale phenomenon reveals the physics inside composites in micro scale and helps the understanding of the process of nano fragmentation.Unidirectional carbon fiber composites were tested under multi-axial loading conditions including tensile/compression/shear loadings along and perpendicular to the fiber direction. Compression dominated tests showed a brittle fracture mode like local kicking/buckling, while tension dominated tests showed a fracture mode like delamination and fiber breakage. Simple shear tests with displacement control showed matrix material hardening and softening before total failure. The proposed modeling framework is successfully applied to the PMCs. A new parameter ? was introduced to represent different loading conditions of PMCs. Numerical simulations using finite element method well duplicated the anisotropic elasticity and plasticity of this material. Failure features like delamination was simulated using cohesive surface feature. It is also applied to carbon fiber composite laminates to further validate the proposed model.A round of experimental study on high volume fraction of metallic matrix nano composites was conducted, including uniaxial tension, uniaxial compression, and three-point bending. The example materials were two magnesium matrix composites reinforced with 10 and 15% vol. SiC particles (50nm size). Brittle fracture mode was exhibited under uniaxial tension and three-point bending, while shear dominated ductile fracture mode (up to 12% fracture strain) was observed under uniaxial compression. Transferring the Modified Mohr Coulomb (MMC) ductile fracture model to the stress based MMC model (sMMC), the proposed modeling framework is applied to this material. This model has been demonstrated to be capable of predicting the coexistence of brittle and ductile fracture modes under different loading conditions for MMCs. Numerical simulations using finite element method well duplicated the material strength, fracture initiation sites and crack propagation modes of the Mg/SiC nano composites with a good accuracy.
Show less - Date Issued
- 2018
- Identifier
- CFE0007078, ucf:51977
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007078
- Title
- Design, Synthesis, Stability, and Photocatalytic Studies of Sustainable Metal-Organic Frameworks.
- Creator
-
Logan, Matthew, Uribe Romo, Fernando, Zhai, Lei, Yuan, Yu, Kuebler, Stephen, Rahman, Talat, University of Central Florida
- Abstract / Description
-
The presented dissertation focuses on the design, synthesis, and characterization of metal-organic frameworks (MOFs) composed of earth-abundant elements the exhibit photoredox activity and studied their application as heterogeneous photocatalysts in organic synthesis and in solar-to-chemical energy conversion. In particular, the structure-property relationships of titanium-based MOFs relating the structure of the organic building unit and the photophysical and photochemical activity of the...
Show moreThe presented dissertation focuses on the design, synthesis, and characterization of metal-organic frameworks (MOFs) composed of earth-abundant elements the exhibit photoredox activity and studied their application as heterogeneous photocatalysts in organic synthesis and in solar-to-chemical energy conversion. In particular, the structure-property relationships of titanium-based MOFs relating the structure of the organic building unit and the photophysical and photochemical activity of the solid material is studied. The first novel family of seven MOFs isoreticular to MIL-125-NH2, includes functionalized with N-alkyl groups with increasing chain length (methyl to heptyl) and with varying connectivity (primary or secondary). The functionalized materials displayed reduced optical bandgaps correlated with the increased inductive donor ability of the alkyl substituents, enhanced excited-state lifetimes, mechanistic information towards visible light CO2 reduction, and improved water stability. The second family of titanium MOFs was prepared with a new secondary building unit and organic links of varying lengths, for which Their crystal structure was solved utilizing powder X-ray diffraction crystallography. This work provides guidelines for the next generation of photocatalyst for the conversion of solar-to-chemical energy and other organic transformations.
Show less - Date Issued
- 2018
- Identifier
- CFE0007219, ucf:52217
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007219
