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- Title
- Analyzing Destination Choices of Tourists and Residents from Location Based Social Media Data.
- Creator
-
Hasnat, Md Mehedi, Hasan, Samiul, Abdel-Aty, Mohamed, Eluru, Naveen, University of Central Florida
- Abstract / Description
-
Ubiquitous uses of social media platforms in smartphones have created an opportunity to gather digital traces of individual activities at a large scale. Traditional travel surveys fall short in collecting longitudinal travel behavior data for a large number of people in a cost effective way, especially for the transient population such as tourists. This study presents an innovating methodological framework, using machine learning and econometric approaches, to gather and analyze location...
Show moreUbiquitous uses of social media platforms in smartphones have created an opportunity to gather digital traces of individual activities at a large scale. Traditional travel surveys fall short in collecting longitudinal travel behavior data for a large number of people in a cost effective way, especially for the transient population such as tourists. This study presents an innovating methodological framework, using machine learning and econometric approaches, to gather and analyze location-based social media (LBSM) data to understand individual destination choices. First, using Twitter's search interface, we have collected Twitter posts of nearly 156,000 users for the state of Florida. We have adopted several filtering techniques to create a reliable sample from noisy Twitter data. An ensemble classification technique is proposed to classify tourists and residents from user coordinates. The performance of the proposed classifier has been validated using manually labeled data and compared against the state-of-the-art classification methods. Second, using different clustering methods, we have analyzed the spatial distributions of destination choices of tourists and residents. The clusters from tourist destinations revealed most popular tourist spots including emerging tourist attractions in Florida. Third, to predict a tourist's next destination type, we have estimated a Conditional Random Field (CRF) model with reasonable accuracy. Fourth, to analyze resident destination choice behavior, this study proposes an extensive data merging operation among the collected Twitter data and different geographic database from state level data libraries. We have estimated a Panel Latent Segmentation Multinomial Logit (PLSMNL) model to find the characteristics affecting individual destination choices. The proposed PLSMNL model is found to better explain the effects of variables on destination choices compared to trip-specific Multinomial Logit Models. The findings of this study show the potential of LBSM data in future transportation and planning studies where collecting individual activity data is expensive.
Show less - Date Issued
- 2018
- Identifier
- CFE0007012, ucf:52028
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007012
- Title
- The Relationship between Course Syllabi and Participant Evaluation Reactions Across Web-based and Face-to-Face Courses.
- Creator
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Glerum, David, Wooten, William, Fritzsche, Barbara, Yee, Kevin, University of Central Florida
- Abstract / Description
-
A common form of training or education evaluation involves the examination of course participant reactions towards various aspects of the course for summative evaluation purposes. Participant reactions have been examined within the framework of a comparison between online and face to face courses often with a slight positive weight towards online courses (Sitzmann et al., 2006). Past research on this topic has denoted a need for studies examining the relationship between objective course...
Show moreA common form of training or education evaluation involves the examination of course participant reactions towards various aspects of the course for summative evaluation purposes. Participant reactions have been examined within the framework of a comparison between online and face to face courses often with a slight positive weight towards online courses (Sitzmann et al., 2006). Past research on this topic has denoted a need for studies examining the relationship between objective course characteristics and participant reactions. This paper seeks to examine the relationship between participant reactions of a sample of geographically disbursed teachers enrolled in a large, national professional development company and objective course characteristics as communicated by course syllabi within a framework of comparison between online and face to face courses. The delivery format, knowledge base, specificity of course objectives, and student interaction levels were all related to some degree to various participant reactions, although the effect sizes were notably small. In many cases, an interaction between the delivery format and objective course characteristic in question influenced the participant reaction. Objective course characteristics as communicated by the syllabi appeared to be major predictors of participant reactions within the face to face courses that were examined, but not for the online courses. Course development stakeholders are recommended to pay attention to the course syllabus design process and craft quality syllabi that communicate relevant information while concurrently anticipating potential participant reactions. Organizations may be able to align the outline for instruction or (")contract(") as presented by the syllabus with recommendations as offered by participant evaluations so as to instill consistent expectations within the participants and maximize positive reactions towards the courses within which they are enrolled.
Show less - Date Issued
- 2011
- Identifier
- CFE0004113, ucf:49119
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004113
- Title
- ADAPTIVE FEEDBACK IN SIMULATION-BASED TRAINING.
- Creator
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Billings, Deborah, Gilson, Richard, University of Central Florida
- Abstract / Description
-
Feedback is essential to guide performance in simulation-based training (SBT) and to refine learning. Generally outcomes improve when feedback is delivered with personalized tutoring that tailors specific guidance and adapts feedback to the learner in a one-to-on environment. Therefore, emulating by automation these adaptive aspects of human tutors in SBT systems should be an effective way to train individuals. This study investigates the efficacy of automating different types of feedback in...
Show moreFeedback is essential to guide performance in simulation-based training (SBT) and to refine learning. Generally outcomes improve when feedback is delivered with personalized tutoring that tailors specific guidance and adapts feedback to the learner in a one-to-on environment. Therefore, emulating by automation these adaptive aspects of human tutors in SBT systems should be an effective way to train individuals. This study investigates the efficacy of automating different types of feedback in a SBT system. These include adaptive bottom-up feedback (i.e., detailed feedback, changing to general as proficiency develops) and adaptive top-down feedback (i.e., general feedback, changing to detailed if performance fails to improve). Other types of non-adaptive feedback were included for performance comparisons as well as to examine the overall cognitive load. To test hypotheses, 130 participants were randomly assigned to five conditions. Two feedback conditions employed adaptive approaches (bottom-up and top-down), two used non-adaptive approaches (constant detailed and constant general), and one functioned as a control group (i.e., only a performance score was given). After preliminary training on the simulator system, participants completed four simulated search and rescue missions (three training missions and one transfer mission). After each training mission, all participants received feedback relative to the condition they were assigned. Overall performance on missions, knowledge post-test scores, and subjective cognitive load were measured and analyzed to determine the effectiveness of the type of feedback. Results indicate that: (1) feedback generally improves performance, confirming prior research; (2) performance for the two adaptive approaches (bottom-up vs. top-down did not differ significantly at the end of training, but the bottom-up group achieved higher performance levels significantly sooner; (3) performance for the bottom-up and constant detailed groups did not differ significantly, although the trend suggests that adaptive bottom-up feedback may yield significant results in further studies. Overall, these results have implications for the implementation of feedback in SBT and beyond for other computer-based training systems.
Show less - Date Issued
- 2010
- Identifier
- CFE0003225, ucf:48555
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003225
- Title
- INVESTIGATING THE OPTIMAL PRESENTATION OF FEEDBACK IN SIMULATION-BASED TRAINING: AN APPLICATION OF THE COGNITIVE THEORY OF MULTIMEDIA LEARNING.
- Creator
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Van Buskirk, Wendi, Bowers, Clint, University of Central Florida
- Abstract / Description
-
There are many different training interventions that can be used in simulation based training systems (e.g., cueing, hinting, highlighting, deliberate practice, etc.). However, the most widely used training intervention in the military is feedback, most often presented in the form of a debrief. With advances in technology, it is possible to measure and diagnose performance in real-time. Thus it is possible to provide immediate feedback during scenarios. However, training systems designers...
Show moreThere are many different training interventions that can be used in simulation based training systems (e.g., cueing, hinting, highlighting, deliberate practice, etc.). However, the most widely used training intervention in the military is feedback, most often presented in the form of a debrief. With advances in technology, it is possible to measure and diagnose performance in real-time. Thus it is possible to provide immediate feedback during scenarios. However, training systems designers should not consider the timing of feedback in isolation. There are other parameters of feedback that must also be considered which may have an impact on performance. Specifically, feedback content and modality may also have an impact on the appropriate timing of feedback and its' effectiveness in simulation training environments. Moreno and Mayer (2000) propose a cognitive theory of multimedia learning which describes how instruction is perceived and processed by a trainee. Using this theoretical framework, I investigate the optimal use of feedback while considering the interaction of feedback timing, content, and modality in scenario-based training environments. In order to investigate the relationship between the timing, modality, and content of feedback, a 2 (immediate, delayed) X 2 (visual, auditory) X 2 (process, outcome) between-subjects design was used (a no feedback control condition was also included). Ninety participants were randomly assigned to the nine experimental groups. These participants performed a visual-spatial military task called the Forward Observer PC-based Simulation. Results indicated that receiving feedback was beneficial to improve performance as compared to receiving no feedback. As hypothesized, during a visual-spatial task, auditory feedback presented during a scenario led to higher performance than visual feedback. Finally, while I did not support my hypothesis that an interaction between all three components of feedback would affect performance, it is promising that the pattern of results mirrored the hypothesized pattern. Theoretical and practical implications, as well as limitations of the current study and directions for future research are discussed.
Show less - Date Issued
- 2011
- Identifier
- CFE0003604, ucf:48875
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003604
- Title
- QUERY PROCESSING IN LOCATION-BASED SERVICES.
- Creator
-
Liu, Fuyu, Hua, Kien, University of Central Florida
- Abstract / Description
-
With the advances in wireless communication technology and advanced positioning systems, a variety of Location-Based Services (LBS) become available to the public. Mobile users can issue location-based queries to probe their surrounding environments. One important type of query in LBS is moving monitoring queries over mobile objects. Due to the high frequency in location updates and the expensive cost of continuous query processing, server computation capacity and wireless communication...
Show moreWith the advances in wireless communication technology and advanced positioning systems, a variety of Location-Based Services (LBS) become available to the public. Mobile users can issue location-based queries to probe their surrounding environments. One important type of query in LBS is moving monitoring queries over mobile objects. Due to the high frequency in location updates and the expensive cost of continuous query processing, server computation capacity and wireless communication bandwidth are the two limiting factors for large-scale deployment of moving object database systems. To address both of the scalability factors, distributed computing has been considered. These schemes enable moving objects to participate as a peer in query processing to substantially reduce the demand on server computation, and wireless communications associated with location updates. In the first part of this dissertation, we propose a distributed framework to process moving monitoring queries over moving objects in a spatial network environment. In the second part of this dissertation, in order to reduce the communication cost, we leverage both on-demand data access and periodic broadcast to design a new hybrid distributed solution for moving monitoring queries in an open space environment. Location-based services make our daily life more convenient. However, to receive the services, one has to reveal his/her location and query information when issuing location-based queries. This could lead to privacy breach if these personal information are possessed by some untrusted parties. In the third part of this dissertation, we introduce a new privacy protection measure called query l-diversity, and provide two cloaking algorithms to achieve both location k-anonymity and query l-diversity to better protect user privacy. In the fourth part of this dissertation, we design a hybrid three-tier architecture to help reduce privacy exposure. In the fifth part of this dissertation, we propose to use Road Network Embedding technique to process privacy protected queries.
Show less - Date Issued
- 2010
- Identifier
- CFE0003487, ucf:48949
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003487
- Title
- FROM CELERY CITY TO NAVY TOWN: THE IMPACT OF NAVAL AIR STATION SANFORD DURING WORLD WAR II.
- Creator
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Metzger V, Lewis, Cassanello, Robert, University of Central Florida
- Abstract / Description
-
This thesis examines how Naval Air Station (NAS) Sanford impacted the nearby city economically, demographically, and socially during World War II. City commission minutes, newspapers, and census data highlight the efforts of city leaders and their cooperation with the federal government to get a naval base established at Sanford. Thereafter, it assesses the ways in which a naval base garnered economic and demographic development, and organizing among African Americans in a southern city.
- Date Issued
- 2010
- Identifier
- CFE0003349, ucf:48439
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003349
- Title
- COMPETITIVE ACTIONS OF NEW TECHNOLOGY FIRMS: THE RED QUEEN EFFECT AND NEW FIRM PERFORMANCE.
- Creator
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Porter, Robert, Ford, Cameron, University of Central Florida
- Abstract / Description
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The competitive strategy used by a new firm may be the most important strategy it ever employs (Covin & Slevin, 1989; Ferrier, 2001). A well-chosen and executed firm strategy is essential for a firm to realize its potential competitive advantage (Porter, 1981). A firmÂÂ's strategic intent and resulting competitive actions are especially important when firms are new and vulnerable as they strive to learn which strategic actions help them adapt to their rivals actions and...
Show moreThe competitive strategy used by a new firm may be the most important strategy it ever employs (Covin & Slevin, 1989; Ferrier, 2001). A well-chosen and executed firm strategy is essential for a firm to realize its potential competitive advantage (Porter, 1981). A firmÂÂ's strategic intent and resulting competitive actions are especially important when firms are new and vulnerable as they strive to learn which strategic actions help them adapt to their rivals actions and to their environment (Stinchcombe, 1965). Further, the competitive actions that new firms choose to take with rival firms affects the overall competitive dynamics of their industry (Smith, Ferrier, and Ndofor, 2001). One way to explore how the competitive actions of new firms affect their future is to capture and examine their individual competitive moves and countermoves over time (Smith, Grimm, Gannon, & Chen, 1991). Red Queen competition is a particular form of competitive dynamics that is well-suited to explore these issues of new rival firms (Barnett, 2008). Barnett and Sorenson (2002) suggested that competition and learning reinforce one another as organizations develop, and this is what van Valen (1973) referred to as the ÂÂ'Red Queen.ÂÂ' This definition of the Red Queen led to the development of the concept of Red Queen competition and the Red Queen effect. The competitive strategies these new firms use to obtain resources as they adapt, in particular how these firms compete and or cooperate, are key competitive strategies that remain understudied to-date (Amit, Glosten, and Muller, 1990). I explore Red Queen competition, and the ensuing Red Queen Effect, in a complex environmental setting that represents a high technology ecosystem (Arned, 1996, 2010; Iansiti & Levien, 2004a, 2004b; Moore, 1993; Pierce, 2009). New firms in such an ecosystem represent a particularly salient combination of type of firm, firm lifecycle period, and firm environment to examine strategic actions since these firms comprise a significant portion of the high-growth and future of our global economy (Stangler, 2010). Further, due to their need to rapidly adapt in a complex ecosystem, these firms rely heavily on short-lived information resources for competitive advantage (Barney, 1991; Nelson and Winter, 1982; Omerzel, 2008). To place this research in context, I consider the moderating effects of key environmental ecosystem resource conditions (Dess & Beard, 1984; Miller & Friesen, 1983; Sharfman & Dean, 1991). Empirical studies to-date have yielded mixed results and left unanswered questions about the basic components and the effects of Red Queen competition. To address these issues I explore this literature in chapter one of the dissertation, and in chapter two I develop a theoretical model of Red Queen competition that draws on the available empirical and theoretical literature to-date. Due to the mixed finding from the empirical results, I develop a precise agent-based simulation model of Red Queen competition in chapter three to facilitate data collection. Using this data I test a series of hypotheses designed to explore the fundamentals of Red Queen competition, specifically how escalating competitive activity for resources among new firms impacts their survival and performance. In addition, the moderating effect of environmental changes on Red Queen competition is also tested to explore the affect of context on Red Queen competition. Chapter four explains the findings from these hypotheses, future research directions, implications and limitations from the research, and my concluding thoughts.
Show less - Date Issued
- 2010
- Identifier
- CFE0003452, ucf:48389
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003452
- Title
- COMPUTER BASED INTERVENTION AND ITS EFFECT ON BENCHMARK TEST SCORES OF ENGLISH LANGUAGE LEARNERS.
- Creator
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Berrio, Gabriel, Martin, Suzanne, University of Central Florida
- Abstract / Description
-
The Florida Department of EducationÂÂ's (FLDOE) Adequate Yearly Progress (AYP) Report (2007) listed and defined students who are in the process of learning English as a second language as English Language Learners (ELL). The graduation rate of English Language Learners in Florida is consistently smaller than the graduation rate of the total population of students (Echevarria, Short and Powers, 2006) in part due to the requirement for students to pass the FCAT in order...
Show moreThe Florida Department of EducationÂÂ's (FLDOE) Adequate Yearly Progress (AYP) Report (2007) listed and defined students who are in the process of learning English as a second language as English Language Learners (ELL). The graduation rate of English Language Learners in Florida is consistently smaller than the graduation rate of the total population of students (Echevarria, Short and Powers, 2006) in part due to the requirement for students to pass the FCAT in order to graduate. ELL students face the challenge of having to learn a different language, learn the subject area content in that language, and often-times pass a standardized test in order to graduate. In Florida districts, ELL is categorized as a subgroup often times not meeting adequate yearly progress in Reading (Florida Department of Education 2007). This study measured the effectiveness of a district approved computer based intervention in increasing student achievement for English Language Learners as identified by the Florida Department of Education (US DOE, 2009).
Show less - Date Issued
- 2010
- Identifier
- CFE0003445, ucf:48403
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003445
- Title
- ADVANCED PRACTICE NURSING IN THE FAITH COMMUNITY SETTING: A CASE STUDY.
- Creator
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Lindsey, Chianta, Chase, Susan, University of Central Florida
- Abstract / Description
-
The purpose of this case study is to demonstrate the effectiveness of an Advanced Practice Nurse in providing spiritual and nursing care within a faith community setting. The study will describe the process of developing a Parish Nurse program using a Nurse Practitioner to offer wholistic health care to parishioners. It will also illustrate the collaborative process of developing a free health center within a faith based organization, using the Nurse Practitioner to manage the health center...
Show moreThe purpose of this case study is to demonstrate the effectiveness of an Advanced Practice Nurse in providing spiritual and nursing care within a faith community setting. The study will describe the process of developing a Parish Nurse program using a Nurse Practitioner to offer wholistic health care to parishioners. It will also illustrate the collaborative process of developing a free health center within a faith based organization, using the Nurse Practitioner to manage the health center and deliver health care services. In order to demonstrate the need for parish nurse care, the case study used an anonymous survey to provide insight into the health status of the congregation, as well as to determine perceived needs of parishioners. Excerpts from the researcherÂÂ's journal and audio-taped interviews of parishioners and key leaders within the community was used to express congregantsÂÂ' experiences of receiving parish nurse care, and to convey the need for a free community health center in the target population. A utilization review was conducted to demonstrate the profile of the patients who have accessed the services of the health center. The findings revealed three commons themes of parish nurse care; presence, spiritual support, and health care liaison. The study also revealed parishioners had an expedited referral process and improved patient provider relationships. Additional findings determined that the free health center was able to be operated by many of the members of the faith based organization, and was effective in managing chronic conditions such as hypertension and diabetes. Advanced Practice Nurses who are Parish Nurses have an opportunity to practice in a more wholistic manner, and offer advanced level care to parishioners and the community at large to improve health outcomes.
Show less - Date Issued
- 2010
- Identifier
- CFE0003308, ucf:48510
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003308
- Title
- INCREASING PARENTAL AWARENESS AND MONITORING: THE DEVELOPMENT AND EVALUATION OF A WEB-BASED PROGRAM TO EMPOWER PARENTS TO REDUCE UNDERAGE ALCOHOL USE.
- Creator
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Brown, Pamela, Dunn, Michael, University of Central Florida
- Abstract / Description
-
Parent attitudes about underage alcohol use and parent monitoring of the activities of their adolescent children have been found to be directly related to the likelihood of underage alcohol use. Unfortunately, there are relatively few programs or resources available to parents to assist them to reduce their childrenÂÂ's potential for early and problematic alcohol involvement. In an effort to address this need, the present project entailed the development and evaluation...
Show moreParent attitudes about underage alcohol use and parent monitoring of the activities of their adolescent children have been found to be directly related to the likelihood of underage alcohol use. Unfortunately, there are relatively few programs or resources available to parents to assist them to reduce their childrenÂÂ's potential for early and problematic alcohol involvement. In an effort to address this need, the present project entailed the development and evaluation of a web-based psychoeducational program entitled, Increasing Parental Awareness and Monitoring (iPAM). This online program begins to fill the gap in effective and convenient programming focused on development of parent skills and awareness. The content of the program is based on parenting factors that have been consistently found to correspond to underage alcohol use. The format includes engaging and interactive components that function to promote increased parent knowledge of the problem of underage drinking. In addition, the program is designed to alter permissive or ambivalent attitudes regarding underage alcohol use, and increase parental behaviors that have shown to be effective in reducing youth alcohol involvement. A randomized controlled trial was conducted (n = 34 control; n = 33 experimental) with parents of adolescents in Central Florida who were asked to complete measures before exposure to the program and again approximately one month later. Findings revealed significant differences between the iPAM group and the control group. Specifically, an increase in parent knowledge about underage alcohol use and increased parental monitoring of their adolescent children was revealed. There was also a main effect for time with regard to increased parent-child communication about alcohol. Additionally, while both groups revealed increased communication, the experimental group revealed greater frequency of communication about alcohol although not significantly.
Show less - Date Issued
- 2010
- Identifier
- CFE0003389, ucf:48454
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003389
- Title
- EFFECT OF COLLABORATIVE PLANNING FOR AN ACTIVITY-BASED APPROACH TO EARLY INTERVENTION FOR CHILDREN WITH AUTISM SPECTRUM DISORDERS ACROSS SCHOOL AND HOME ENVIRONMENTS.
- Creator
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Salazar, Marisa, Cross, Lee, University of Central Florida
- Abstract / Description
-
As the prevalence of autism spectrum disorders (ASD) continues to rise, families and educators are challenged with providing intensive, evidence-based practices in the least restrictive environment. Evidence exists for a variety of effective intervention approaches. Selection of appropriate interventions requires consideration of the individual needs of the child and family. An activity-based approach to early intervention combines strategies from a variety of evidence-based practices and...
Show moreAs the prevalence of autism spectrum disorders (ASD) continues to rise, families and educators are challenged with providing intensive, evidence-based practices in the least restrictive environment. Evidence exists for a variety of effective intervention approaches. Selection of appropriate interventions requires consideration of the individual needs of the child and family. An activity-based approach to early intervention combines strategies from a variety of evidence-based practices and allows for intensity of instruction through distributed opportunities for practice. Brief teaching interactions are elicited within the context of typical routines and activities throughout the day. Thus, intervention can be provided in inclusive classroom settings as well as at home, without disrupting the ongoing activities and routines. The purpose of the study was to determine the effects of collaborative planning for an activity- based approach to early intervention for children with ASD across school and home settings. Dependent measures included the combined rate of learning opportunities delivered by the teacher and parent across settings as well as the combined rate of the child's correct demonstrations for an Individualized Education Plan (IEP) goal. Teacher and parent perceptions of the value and effectiveness of collaborative planning for an activity-based approach to early intervention were also assessed using pre- and post-survey responses as well as information from a final interview. Participants were a preschool-aged boy with ASD, his mother, and his preschool teacher. A single subject, multiple-probe design was selected to analyze the effect of collaborative planning for an activity-based approach to intervention for a young child with ASD across school and home settings. The teacher and parent selected three matched routines that typically occur both at school and at home as the context for embedding activity-based learning opportunities to iii address a selected IEP goal. Results indicated that following collaborative planning meetings for each of the routines, there was both an increase in the collective learning opportunities delivered at school and at home, as well as a simultaneous increase in child outcomes for the targeted IEP objective in both settings. Responses from the teacher and parent pre- and post-surveys and final interviews provided social validation for the ease and practicality of collaborative planning for activity-based intervention. Both the teacher and parent felt confident in supporting the child's IEP goal within the context of typical daily routines. The teacher also expressed that the collaborative planning helped her to really focus on the child's individualized goal. Furthermore, both the teacher and the parent affirmed the intervention's potential for generalization. Collaborative planning to embed children's goals within the context of typical routines both at school and at home allowed for a collective increase in learning opportunities and related child performance on an individualized goal that may not have otherwise been possible. By including the parent as an active an equal decision maker in the educational planning process, intervention at school was enhanced and carried over into the home. The use of collaborative planning for activity-based intervention with both the teacher and the parent strengthened the power of instruction for an IEP goal by providing multiple and varied learning opportunities throughout the day and across settings, ultimately increasing child outcomes.
Show less - Date Issued
- 2011
- Identifier
- CFE0003892, ucf:48717
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003892
- Title
- VISION BASED TRAJECTORY TRACKING OF SPACE DEBRIS IN CLOSE PROXIMITY VIA INTEGRATED ESTIMATION AND CONTROL.
- Creator
-
Li, Ni, Xu, Yunjun, University of Central Florida
- Abstract / Description
-
The increasingly cluttered environment in space is placing a premium on techniques capable of tracking and estimating the trajectory of space debris. Unlike the debris smaller than 1 cm or larger than 10 cm, it is always a challenge for spacecraft or satellite mission designers to consider explicitly the ones ranged from 1 cm to 10 cm a priori. To tackle this challenge, a vision based debris' trajectory tracking method in close proximity using two cameras onboard satellites in a formation is...
Show moreThe increasingly cluttered environment in space is placing a premium on techniques capable of tracking and estimating the trajectory of space debris. Unlike the debris smaller than 1 cm or larger than 10 cm, it is always a challenge for spacecraft or satellite mission designers to consider explicitly the ones ranged from 1 cm to 10 cm a priori. To tackle this challenge, a vision based debris' trajectory tracking method in close proximity using two cameras onboard satellites in a formation is presented in the thesis. Also to differentiate the target debris from other clutters, data association is investigated. A two-stage nonlinear robust controller is developed to adjust the attitude of the satellites such that the desired field of view can be achieved for the target debris. Capabilities of the proposed integrated estimation and control methods are validated in the simulations.
Show less - Date Issued
- 2011
- Identifier
- CFE0003731, ucf:48775
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003731
- Title
- Gauging Training Effectiveness of Virtual Environment Simulation Based Applications for an Infantry Soldier Training Task.
- Creator
-
Maxwell, Douglas, Kincaid, John, Shumaker, Randall, Barber, Daniel, Sottilare, Robert, University of Central Florida
- Abstract / Description
-
The U.S. Army Training and Doctrine Command's Army Learning Concept 2015 and Army Training Concept 2025 are documents that discuss the need for an adaptive soldier learning model with a flexible training delivery methodology. The U.S. Army has been investing in serious gaming technology for the past two decades as a cost effective means to teach tactics and strategy. Today, the U.S. Army is seeking to expand its application of virtual environment training to areas such as cultural awareness...
Show moreThe U.S. Army Training and Doctrine Command's Army Learning Concept 2015 and Army Training Concept 2025 are documents that discuss the need for an adaptive soldier learning model with a flexible training delivery methodology. The U.S. Army has been investing in serious gaming technology for the past two decades as a cost effective means to teach tactics and strategy. Today, the U.S. Army is seeking to expand its application of virtual environment training to areas such as cultural awareness and human network analysis for the infantry soldier. These new expanded applications will require a higher level of non-determinant behavior inside the virtual environment. To meet more of the training needs of the war fighter, the U.S. Army is looking beyond first person perspective games to the cooperative and social gaming experience offered by the MMOG (Massively Multiplayer Online Game) and the VWT (Virtual World Technology). Altogether, these classes of games have the potential to teach leadership skills, social acclimation skills, cultural awareness and practice skills, and critical thinking skills for problem solving in a cost effective manner. Unfortunately, even today there is a paucity of scientific research to support whether this potential may be realized or not. A literature review was performed which covers current concepts in the usage of virtual environments for military individual and team training in the U.S. Army infantry soldier domains. There are many variables involved with the lifecycle of the virtual training activity including the acquisition, information assurance and cyber security, deployment, proper employment, content development and maintenance, and retirement. This discussion goes beyond the traditional topics of graphics and game engine technology and delves deeper into concepts of the importance of proper usage of the environments by the trainees. This dissertation is composed of three studies with two subject pools: experienced soldiers and novice soldiers. The participants in the studies were randomly assigned to one of two training conditions. The training conditions were either a traditional slide-show in a classroom or a virtual environment based training system. The participants were then provided with training for a room clearing tasks in each of the conditions. The independent variables are training condition and soldier condition. The dependent variables are individual performance, team performance, stress questionnaire scores, and workload questionnaire scores. A number of relationships are explored in this dissertation. The first objective of these studies is to attempt to identify any effect the training conditions have on either individual performance or team performance. Lastly, these studies attempt to identify if there is any difference the training conditions have on novice versus experienced subjects' performance during a live assessment.
Show less - Date Issued
- 2015
- Identifier
- CFE0005840, ucf:50924
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005840
- Title
- Content-based Information Retrieval via Nearest Neighbor Search.
- Creator
-
Huang, Yinjie, Georgiopoulos, Michael, Anagnostopoulos, Georgios, Hu, Haiyan, Sukthankar, Gita, Ni, Liqiang, University of Central Florida
- Abstract / Description
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Content-based information retrieval (CBIR) has attracted significant interest in the past few years. When given a search query, the search engine will compare the query with all the stored information in the database through nearest neighbor search. Finally, the system will return the most similar items. We contribute to the CBIR research the following: firstly, Distance Metric Learning (DML) is studied to improve retrieval accuracy of nearest neighbor search. Additionally, Hash Function...
Show moreContent-based information retrieval (CBIR) has attracted significant interest in the past few years. When given a search query, the search engine will compare the query with all the stored information in the database through nearest neighbor search. Finally, the system will return the most similar items. We contribute to the CBIR research the following: firstly, Distance Metric Learning (DML) is studied to improve retrieval accuracy of nearest neighbor search. Additionally, Hash Function Learning (HFL) is considered to accelerate the retrieval process.On one hand, a new local metric learning framework is proposed - Reduced-Rank Local Metric Learning (R2LML). By considering a conical combination of Mahalanobis metrics, the proposed method is able to better capture information like data's similarity and location. A regularization to suppress the noise and avoid over-fitting is also incorporated into the formulation. Based on the different methods to infer the weights for the local metric, we considered two frameworks: Transductive Reduced-Rank Local Metric Learning (T-R2LML), which utilizes transductive learning, while Efficient Reduced-Rank Local Metric Learning (E-R2LML)employs a simpler and faster approximated method. Besides, we study the convergence property of the proposed block coordinate descent algorithms for both our frameworks. The extensive experiments show the superiority of our approaches.On the other hand, *Supervised Hash Learning (*SHL), which could be used in supervised, semi-supervised and unsupervised learning scenarios, was proposed in the dissertation. By considering several codewords which could be learned from the data, the proposed method naturally derives to several Support Vector Machine (SVM) problems. After providing an efficient training algorithm, we also study the theoretical generalization bound of the new hashing framework. In the final experiments, *SHL outperforms many other popular hash function learning methods. Additionally, in order to cope with large data sets, we also conducted experiments running on big data using a parallel computing software package, namely LIBSKYLARK.
Show less - Date Issued
- 2016
- Identifier
- CFE0006327, ucf:51544
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006327
- Title
- Evaluation of the Expectancy Challenge Alcohol Literacy Curriculum (ECALC) for High School Students.
- Creator
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Boucher, Alyssa, Dunn, Michael, Renk, Kimberly, Dunn, Stacey, Linkovich Kyle, Tiffany, University of Central Florida
- Abstract / Description
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Prevention efforts targeted at children and adolescents are important because alcohol consumption contributes to the three leading causes of death in this among 12-20 year-olds: unintentional injury, homicide, and suicide. Research on the causes of alcohol misuse traditionally focused on pharmacological and genetic explanations, but models have expanded to include cognitive processes in the development of alcohol use patterns. Alcohol expectancies, or beliefs about the effects of alcohol, are...
Show morePrevention efforts targeted at children and adolescents are important because alcohol consumption contributes to the three leading causes of death in this among 12-20 year-olds: unintentional injury, homicide, and suicide. Research on the causes of alcohol misuse traditionally focused on pharmacological and genetic explanations, but models have expanded to include cognitive processes in the development of alcohol use patterns. Alcohol expectancies, or beliefs about the effects of alcohol, are an important influence on drinking behavior. Expectancies exist prior to the initial drinking experience, predict the onset of alcohol consumption, differentiate both children and adults in terms of light- and heavy-drinking patterns, mediate the influence of precursors on alcohol use, and when manipulated, result in significantly decreased alcohol consumption in heavy-drinking college students.The Expectancy Challenge Alcohol Literacy Curriculum (ECALC) is a web-based, interactive intervention that leverages technology in order to challenge students' expectancies through a media literacy presentation based on research findings. The 45-minute curriculum links exposure to alcohol media with expectancy beliefs and drinking decisions, and focuses on decreasing the positive reinforcing value of alcohol. The ECALC does not necessarily erase former expectations, but introduces new information about the physiological effects of alcohol that may compete with pre-existing positive expectations for influence over the individual's behavior. Though the ECALC has been validated with college students, the present study involved revising and evaluating the program to be appropriate for high school students. Results revealed changes in expectancy processes for students who reported alcohol use initiation and changes in mean BAC among females in this group.
Show less - Date Issued
- 2016
- Identifier
- CFE0006294, ucf:51581
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006294
- Title
- Classification of Silicone-Based Personal and Condom Lubricants Using DART-TOFMS.
- Creator
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Harvey, Lauren, Bridge, Candice, Sigman, Michael, Campiglia, Andres, Yestrebsky, Cherie, University of Central Florida
- Abstract / Description
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Sexual lubricants are used to enable sexual encounters. There are different types of sexual lubricants such as water-based, oil-based, and silicone-based. They come pre-applied to condoms and separately in bottles as personal lubricants. Although sexual lubricants are intended for consensual use, they are also unfortunately used during the commission of sexual assaults. The analysis of sexual lubricants facilitates sexual assault investigations. With the increased usage of condoms in sexual...
Show moreSexual lubricants are used to enable sexual encounters. There are different types of sexual lubricants such as water-based, oil-based, and silicone-based. They come pre-applied to condoms and separately in bottles as personal lubricants. Although sexual lubricants are intended for consensual use, they are also unfortunately used during the commission of sexual assaults. The analysis of sexual lubricants facilitates sexual assault investigations. With the increased usage of condoms in sexual assault cases, the potential of collected DNA evidence in each case is reduced. In the absence of biological evidence, the presence of sexual lubricants after a sexual assault can provide an additional link between a suspect and the crime scene and/or victim. Having the ability to compare known and unknown sexual lubricants may be the only actionable information available for investigators. Current lubricant analysis only classifies samples into lubricant types based on the major component such as glycerol, petrolatum, and polydimethylsiloxane for water-based, oil-based, and silicone-based lubricants respectively. Differentiation within major types has not been explored. Previously, protocols have been developed to detect and categorize personal lubricants using Fourier transform infrared (FTIR) spectroscopy, gas chromatography-mass spectrometry (GC-MS), liquid chromatography mass spectrometry (LC-MS), and pyrolysis GC-MS. FTIR is routinely used as a screening tool to detect peaks of the major lubricant components and the mass spectrometry (MS) techniques are commonly used to confirm the presence of some of the major components, excluding PDMS.This thesis focused on the differentiation of silicone-based personal and condom lubricants because it is a common type of lubricant due to its ability to reduce friction for a longer period of time. Fifty-six (56) silicone personal and condom lubricants were analyzed to identify unique characteristics that can be used to determine individual sub-classes and test those sub-classes. Direct analysis in real time-time of flight mass spectrometry (DART-TOFMS) was utilized because minor and unique molecular ions that could be attributed to different sub-groups can easily be distinguished from the major sample peaks. This is primarily based on the direct mass spectrometry design of the instrumentation that can differentiate minor components from major components that might not be observed using traditional chromatographic separation. The DART source creates molecular ions for individual components in mixed samples under atmospheric conditions in either positive or negative mode. The TOF-MS, which is capable of high resolution and accurate mass analysis, allows more accurate and precise detection of molecular component ions. Additionally, no sample preparation is required to analyze neat samples, which minimizes potential contamination issues. Attenuated total reflectance-FTIR (ATR-FIR) was used to analyze the training set personal lubricants to compare previous methods of analysis to the newly developed DART-TOFMS method of analysis.Principle component analysis (PCA) and cluster analysis were used to identify potential sub-groups and subsequently a classification scheme. Linear discriminant analysis was utilized to conduct leave one out cross validation and to categorize test samples. Eight sub-groups were developed based on the presence and/or absence of PDMS and minor component peaks observed.A classification scheme was developed using the eight sub-groups identified through PCA and cluster analysis. This classification scheme was tested using LDA to classify blind samples. One group includes a scented personal lubricant. Another group includes flavored condom lubricants. The other groups were developed based on the relative intensity of PDMS peaks and minor component peaks. Variation of the intensity of PDMS peaks between and within samples of different lot numbers causes some misclassification of samples. This classification scheme also doesn't take into account real-world factors such as dilution and biodegradation. Although further research is required to create a more stable classification scheme, the identified sub-groups are a good foundation for the creation of a lubricant database and finalized classification scheme.
Show less - Date Issued
- 2016
- Identifier
- CFE0006459, ucf:51415
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006459
- Title
- A framework to generate a smart manufacturing system configurations using agents and optimization.
- Creator
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Nagadi, Khalid, Rabelo, Luis, Lee, Gene, Elshennawy, Ahmad, Ahmad, Ali, University of Central Florida
- Abstract / Description
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Manufacturing is a crucial element in the global economy. During the last decade, the national manufacturing sector loses nearly 30% of its workforce and investments. Consequently, the quality of the domestic goods, global share, and manufacturing capabilities has been declined. Therefore, innovative ways to optimize the usage of the Smart Manufacturing Systems (SMS) are required to form a new manufacturing era. This research is presenting a framework to optimize the design of SMS. This...
Show moreManufacturing is a crucial element in the global economy. During the last decade, the national manufacturing sector loses nearly 30% of its workforce and investments. Consequently, the quality of the domestic goods, global share, and manufacturing capabilities has been declined. Therefore, innovative ways to optimize the usage of the Smart Manufacturing Systems (SMS) are required to form a new manufacturing era. This research is presenting a framework to optimize the design of SMS. This includes the determination of the suitable machines that can perform the job efficiently, the quantity of those machines, and the potential messaging system required for sharing information.Multiple reviews are used to form the framework. Expert machine selection matrix identifies the required machines and machine parameter matrix defines the specifications of those machines. While business process modeling and notation (BPMN) captures the process plan in object-oriented fashion. In addition, to agent unified modeling language (AUML) that guides the application of message sequence diagram and statecharts. Finally, the configuration is obtained from a hybrid simulation model. Agent based-modeling is used to capture the behavior of the machines where discrete event simulation mimics the process flow. A case study of a manufacturing system is used to verify the study. As a result, the framework shows positive outcomes in supporting upper management in the planning phase of establishing a SMS or evaluating an existing one.
Show less - Date Issued
- 2016
- Identifier
- CFE0006540, ucf:51311
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006540
- Title
- A Training Effectiveness Evaluation of UH-60A/L Simulated Environments: An Interdisciplinary Approach.
- Creator
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Goodwin, Martin, Reinerman, Lauren, Szalma, James, Goldiez, Brian, Goldberg, Benjamin, University of Central Florida
- Abstract / Description
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The U.S. military continues to develop and expand its use of simulation-based aviation training. While traditional simulation-based training continues to be a proven training method, game-based simulation has become more sophisticated and may provide viable training options in some applications. The use of game-based simulation with traditional simulation-based training can potentially reduce costs, enhance return on investment, advance training objectives, and inform future training...
Show moreThe U.S. military continues to develop and expand its use of simulation-based aviation training. While traditional simulation-based training continues to be a proven training method, game-based simulation has become more sophisticated and may provide viable training options in some applications. The use of game-based simulation with traditional simulation-based training can potentially reduce costs, enhance return on investment, advance training objectives, and inform future training environment designs. Current fiscal limitations are driving the need for more efficient training methods, while operational requirements are dictating training protocols that produce optimum levels of readiness. The gap between fiscal constraints and desired training outcomes can be addressed by investigating whether lower-cost, game-based simulations may potentially augment higher-cost, traditional simulation-based training approaches for specific training tasks. Performing a valid investigation of the value of these simulation environments depends on a thorough evaluation of their training effectiveness. However, current approaches to Training Effectiveness Evaluation (TEE) do not adequately address the complete range of factors required to effectively investigate this gap. The present effort leverages research from human performance assessment, neurophenomenology, and instructional science to identify and integrate a set of empirically validated measures that contribute to training effectiveness. From this foundation, an interdisciplinary approach to performing TEEs for simulation training is introduced that addresses the shortcomings of current practices. This approach is validated in a use case involving the evaluation of U.S. Army Aviation collective training.
Show less - Date Issued
- 2017
- Identifier
- CFE0006942, ucf:51671
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006942
- Title
- Modeling Dense Storage Systems With Location Uncertainty.
- Creator
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Awwad, Mohamed, Pazour, Jennifer, Elshennawy, Ahmad, Thompson, William, Leon, Steven, University of Central Florida
- Abstract / Description
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This dissertation focuses on developing models to study the problem of searching and retrieving items in a dense storage environment. We consider a special storage configuration called an inverted T configuration, which has one horizontal and one vertical aisle. Inverted T configurations have fewer aisles than a traditional aisle-based storage environment. This increases the storage density; however, requires that some items to be moved out of the way to gain access to other more deeply...
Show moreThis dissertation focuses on developing models to study the problem of searching and retrieving items in a dense storage environment. We consider a special storage configuration called an inverted T configuration, which has one horizontal and one vertical aisle. Inverted T configurations have fewer aisles than a traditional aisle-based storage environment. This increases the storage density; however, requires that some items to be moved out of the way to gain access to other more deeply stored items. Such movement can result in item location uncertainty. When items are requested for retrieval in a dense storage environment with item location uncertainty, searching is required. Dense storage has a practical importance as it allows for the use of available space efficiently, which is especially important with the scarce and expensive space onboard of US Navy's ships that form a sea base. A sea base acts as a floating distribution center that provides ready issue material to forces ashore participating in various types of missions. The sea basing concept and the importance of a sea base's responsiveness is our main motivation to conduct this research.In chapter 2, we review three major bodies of literature: 1) sea based logistics, 2) dense storage and 3) search theory. Sea based logistics literature mostly focuses on the concept and the architecture of a sea base, with few papers developing mathematical models to solve operational problems of a sea base, including papers handling the logistical and sustainment aspects. Literature related to dense storage can be broken down into work dealing with a dense storage environment with an inverted T configuration and other papers dealing with other dense storage configurations. It was found that some of the dense storage literature was motivated by the same application, i.e. sea based logistics. Finally, we surveyed the vast search theory literature and classification of search environments. This research contributes to the intersection of these three bodies of literature. Specifically, this research, motivated by the application of sea basing, develops search heuristics for dense storage environments that require moving items out of the way during searching. In chapter 3, we present the problem statements. We study two single-searcher search problems. The first problem is searching for a single item in an inverted T dense storage environment. The second one is searching for one or more items in an inverted T storage environment with items stacked over each other in the vertical direction.In chapter 4, we present our first contribution. In this contribution we propose a search plan heuristic to search for a single item in an inverted T, k-deep dense storage system with the objective of decreasing the expected search time in such an environment. In this contribution, we define each storage environment entirely by the accessibility constant and the storeroom length. In addition, equations are derived to calculate each component of the search time equation that we propose: travel, put-back and repositioning. Two repositioning policies are studied. We find that a repositioning policy that uses the open aisle locations as temporary storage locations and requires put-back of these items while searching is recommended. This recommendation is because such a policy results in lower expected search time and lower variability than a policy that uses available space outside the storage area and handles put-back independently of the search process. Statistical analysis is used to analyze the numerical results of the first contribution and to analyze the performances of both repositioning polices. We derive the probability distribution of search times in a storeroom with small configurations in terms of the accessibility constant and length. It was found that this distribution can be approximated using a lognormal probability distribution with a certain mean and standard deviation. Knowing the probability distribution provides the decision makers with the full range of all possible probabilities of search times, which is useful for downstream planning operations.In chapter 5, we present the second contribution, in which we propose a search plan heuristic but for multiple items in an inverted T, k-deep storage system. Additionally, we consider stacking multiple items over each other. Stacking items over each other, increases the number of stored items and allows for the utilization of the vertical space. In this second contribution, we are using the repositioning policy that proved its superiority in the first contribution. This contribution investigates a more general and a much more challenging environment than the one studied in the first contribution. In the second environment, to gain access to some items, not only may other items need to be moved out of the way, but also the overall number of movements for items within the system will be highly affected by the number of items stacked over each other. In addition, the searcher is given a task that includes searching and retrieving a set of items, rather than just one item.For the second contribution, the performance of the search heuristic is analyzed through a Statistical Design of Experiments, and it was found that searching and retrieving multiple items instead of just a single item, would decrease the variability in search times for each storeroom configuration. Finally, in chapter 6, conclusions of this research and suggestions for future research directions are presented.
Show less - Date Issued
- 2015
- Identifier
- CFE0006256, ucf:51045
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006256
- Title
- Mathematical Modeling of Infectious Diseases with Latency: Homogeneous Mixing and Contact Network.
- Creator
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Carlson, Keith, Shuai, Zhisheng, Mohapatra, Ram, Guha, Ratan, University of Central Florida
- Abstract / Description
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In mathematical epidemiology, the standard compartmental models assume homogeneous mixingin the host population, in contrast to the disease spread process over a real host contact network. One approach to incorporating heterogeneous mixing is to consider the population to be a networkof individuals whose contacts follow a given probability distribution. In this thesis we investigate in analogy both homogeneous mixing and contact network models for infectious diseases that admit latency...
Show moreIn mathematical epidemiology, the standard compartmental models assume homogeneous mixingin the host population, in contrast to the disease spread process over a real host contact network. One approach to incorporating heterogeneous mixing is to consider the population to be a networkof individuals whose contacts follow a given probability distribution. In this thesis we investigate in analogy both homogeneous mixing and contact network models for infectious diseases that admit latency periods, such as dengue fever, Ebola, and HIV. We consider the mathematics of thecompartmental model as well as the network model, including the dynamics of their equations from the beginning of disease outbreak until the disease dies out. After considering the mathematical models we perform software simulations of the disease models. We consider epidemic simulationsof the network model for three different values of R0 and compare the peak infection numbers and times as well as disease outbreak sizes and durations. We examine averages of these numbers for one thousand simulation runs for three values of R0. Finally we summarize results and consider avenues for further investigation.
Show less - Date Issued
- 2016
- Identifier
- CFE0006276, ucf:51054
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006276
