Current Search: virtual (x)
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Title
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CONFORMAL TRACKING FOR VIRTUAL ENVIRONMENTS.
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Creator
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Davis, Jr., Larry Dennis, Rolland, Jannick P., University of Central Florida
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Abstract / Description
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A virtual environment is a set of surroundings that appears to exist to a user through sensory stimuli provided by a computer. By virtual environment, we mean to include environments supporting the full range from VR to pure reality. A necessity for virtual environments is knowledge of the location of objects in the environment. This is referred to as the tracking problem, which points to the need for accurate and precise tracking in virtual environments.Marker-based tracking is a technique...
Show moreA virtual environment is a set of surroundings that appears to exist to a user through sensory stimuli provided by a computer. By virtual environment, we mean to include environments supporting the full range from VR to pure reality. A necessity for virtual environments is knowledge of the location of objects in the environment. This is referred to as the tracking problem, which points to the need for accurate and precise tracking in virtual environments.Marker-based tracking is a technique which employs fiduciary marks to determine the pose of a tracked object. A collection of markers arranged in a rigid configuration is called a tracking probe. The performance of marker-based tracking systems depends upon the fidelity of the pose estimates provided by tracking probes.The realization that tracking performance is linked to probe performance necessitates investigation into the design of tracking probes for proponents of marker-based tracking. The challenges involved with probe design include prediction of the accuracy and precision of a tracking probe, the creation of arbitrarily-shaped tracking probes, and the assessment of the newly created probes.To address these issues, we present a pioneer framework for designing conformal tracking probes. Conformal in this work means to adapt to the shape of the tracked objects and to the environmental constraints. As part of the framework, the accuracy in position and orientation of a given probe may be predicted given the system noise. The framework is a methodology for designing tracking probes based upon performance goals and environmental constraints. After presenting the conformal tracking framework, the elements used for completing the steps of the framework are discussed. We start with the application of optimization methods for determining the probe geometry. Two overall methods for mapping markers on tracking probes are presented, the Intermediary Algorithm and the Viewpoints Algorithm.Next, we examine the method used for pose estimation and present a mathematical model of error propagation used for predicting probe performance in pose estimation. The model uses a first-order error propagation, perturbing the simulated marker locations with Gaussian noise. The marker locations with error are then traced through the pose estimation process and the effects of the noise are analyzed. Moreover, the effects of changing the probe size or the number of markers are discussed.Finally, the conformal tracking framework is validated experimentally. The assessment methods are divided into simulation and post-fabrication methods. Under simulation, we discuss testing of the performance of each probe design. Then, post-fabrication assessment is performed, including accuracy measurements in orientation and position. The framework is validated with four tracking probes. The first probe is a six-marker planar probe. The predicted accuracy of the probe was 0.06 deg and the measured accuracy was 0.083 plus/minus 0.015 deg. The second probe was a pair of concentric, planar tracking probes mounted together. The smaller probe had a predicted accuracy of 0.206 deg and a measured accuracy of 0.282 plus/minus 0.03 deg. The larger probe had a predicted accuracy of 0.039 deg and a measured accuracy of 0.017 plus/minus 0.02 deg. The third tracking probe was a semi-spherical head tracking probe. The predicted accuracy in orientation and position was 0.54 plus/minus 0.24 deg and 0.24 plus/minus 0.1 mm, respectively. The experimental accuracy in orientation and position was 0.60 plus/minus 0.03 deg and 0.225 plus/minus 0.05 mm, respectively. The last probe was an integrated, head-mounted display probe, created using the conformal design process. The predicted accuracy of this probe was 0.032 plus/minus 0.02 degrees in orientation and 0.14 plus/minus 0.08 mm in position. The measured accuracy of the probe was 0.028 plus/minus 0.01 degrees in orientation and 0.11 plus/minus 0.01 mm in position
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Date Issued
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2004
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Identifier
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CFE0000058, ucf:52856
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0000058
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Title
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DIMENSIONS OF IDENTITY.
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Creator
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Kramer, Alice, Haxton, John David, University of Central Florida
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Abstract / Description
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Imagination and fantasy environments created by writers and artists have always drawn people into their worlds. Advances in technology have blurred the lines between reality and imagination. My interest has always been to question the validity of these worlds and their cultures and to transcend the evolving virtual dimension by fusing it with what we perceive to be reality.
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Date Issued
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2009
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Identifier
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CFE0002632, ucf:48213
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0002632
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Title
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Using a Mixed-Reality Classroom Environment Including English Learners: The Perceptions of Teacher Candidates.
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Creator
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Ashtari, Nooshan, Nutta, Joyce, Hutchinson, Cynthia, Mihai, Florin, Jahani, Shiva, University of Central Florida
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Abstract / Description
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Technological modernization has impacted various fields such as the field of education, teaching, and learning. The traditional classroom and teaching methodologies no longer meet the needs of the new tech-savvy generation. Thus, recently there have been changes in teacher preparation programs in order to prepare teacher candidates to have the skills to respond to such high technological demands. Additionally, the demographics of students attending schools in countries with exceptionally high...
Show moreTechnological modernization has impacted various fields such as the field of education, teaching, and learning. The traditional classroom and teaching methodologies no longer meet the needs of the new tech-savvy generation. Thus, recently there have been changes in teacher preparation programs in order to prepare teacher candidates to have the skills to respond to such high technological demands. Additionally, the demographics of students attending schools in countries with exceptionally high numbers of immigrants such as the United States is another reason to seek novel ways to prepare teachers who have had adequate practice and developed teaching skills needed to reach the English learners (ELs) in their classrooms. Using Multi-User Virtual Environments (MUVEs) has been one solution in order to bridge this gap. EL TLE TeachLivE(TM), which was the focus of this study, is a computer simulated environment that combines real-life participants and digital personas or avatars. The participants of this study were teacher candidates who experienced using EL TLE TeachLivE(TM) to practice the teaching strategies and skills they had been learning about during their teacher preparation program (n=20). This research investigated the perceptions of these teacher candidates about using this mixed-reality classroom environment through observations, questionnaires, focus groups, and individual interviews. A qualitative transcendental phenomenological approach was taken to have a more in-depth understanding of the participants' perceptions about the phenomenon of EL TLE TeachLivE(TM) as a mixed-reality classroom environment in teacher preparation and the meaning they made of their experiences. Through the data analysis three main categories emerged: TCs' general perceptions about the avatars and EL TLE TeachLivE(TM) as a mixed-reality classroom environment, TCs' perceptions of the current use of the EL TLE TeachLivE(TM) in their teacher preparation program, and TCs' perceptions about the future use of EL TLE TeachLivE(TM). The Teacher Candidates' General Perceptions of EL TLE TeachLivE(TM) consisted of the following sub-themes: (a) Video game dissimilarities, (b) Avatar believability and real-life features, (c) Personification of the EL cases, (d) Fear of the unknown, (e) Avatar movement restrictions, and (f) Suspension of disbelief. The Teacher Candidates' Perceptions about the Current Use of EL TLE TeachLivE(TM) included: (a) Importance of prerequisites, (b) Advantages over role-playing, (c) Teaching in front of peers, (d) Group teaching and random selection, (e) Importance of feedback, and (f) Teaching strategies and aha moments.Finally, the Teacher Candidates' Perceptions about the Future Use of EL TLE TeachLivE(TM) incorporated: (a) Changes in the implementation, (b) Elementary vs secondary classrooms, and (c) Gradual practice.
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Date Issued
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2016
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Identifier
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CFE0006255, ucf:51048
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0006255
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Title
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Navigating Sociotechnical Power Structures: Dynamics of Conflict in World of Warcraft's Player versus Player Events.
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Creator
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Root, Rachael, Mishtal, Joanna, Matejowsky, Ty, Underberg-Goode, Natalie, University of Central Florida
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Abstract / Description
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As a result of technological advancement and exponential increases in global access, cross-disciplinary research has recently turned to digital online video games. Most anthropological research within this area has centered around player self-identification, gender construction, and gaming communities. Yet many interactions occur at nodes of dynamic conflict where agentic players navigate intersections of power, which are unaddressed in the scholarly corpus. By utilizing ethnographic methods...
Show moreAs a result of technological advancement and exponential increases in global access, cross-disciplinary research has recently turned to digital online video games. Most anthropological research within this area has centered around player self-identification, gender construction, and gaming communities. Yet many interactions occur at nodes of dynamic conflict where agentic players navigate intersections of power, which are unaddressed in the scholarly corpus. By utilizing ethnographic methods in World of Warcraft's player versus player events, I examine resources, relationships, and tools that underpin player actions and understandings. My findings reveal layered and dynamic patterns of sociotechnical conflict. Players' geographical location impacts access to infrastructure while hardware and software constrain in-game action in fundamental and inescapable ways. Player versus player events add additional restrictions and create fluid situations where players continually negotiate fluctuating social tensions while event-dependent dispersions of power fluctuate between groups and individuals. Players become leaders by legitimizing power in contextually unique ways, and competing imaginaries generate conflicts that are interpreted through game-specific subjectivities. In exploring these occurrences and utilizing theoretical explanations within World of Warcraft contexts, this research contributes to disciplinary understandings and discussions addressing conflict, leadership, and power, and to methodological techniques utilized in virtual world study. By foregrounding how players navigate power differentials in conflict situations, this research informs broader conceptions of how individuals and groups manage social disputes within and outside digital social events, informs game design, and has policy implications for resolving virtual world conflicts in real world courts.
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Date Issued
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2016
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Identifier
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CFE0006172, ucf:51140
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0006172
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Title
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AN EXAMINATION OF ACADEMIC DISHONESTY IN SECONDARY ONLINE ENGLISH EDUCATION.
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Creator
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Middleton, Marissa, Wegmann, Susan, University of Central Florida
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Abstract / Description
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Online schooling is the newest form of education and it is quickly gaining popularity. However, this educational format also comes with one of the challenges that has always been present in schools, which is academic dishonesty. In the English Language Arts content area, academic dishonesty is most often manifested as plagiarism, however, cheating on online quizzes or exams still exists. Although this issue has always been present in English classes, it is becoming more of a concern because...
Show moreOnline schooling is the newest form of education and it is quickly gaining popularity. However, this educational format also comes with one of the challenges that has always been present in schools, which is academic dishonesty. In the English Language Arts content area, academic dishonesty is most often manifested as plagiarism, however, cheating on online quizzes or exams still exists. Although this issue has always been present in English classes, it is becoming more of a concern because of the vast number of technological resources available to students including websites with pre-written papers and the various methods students can now use to instantly communicate with each other. This study combines and synthesizes a literature review and a survey of secondary online English educators at Florida Virtual School to give their perspective on aspects of cheating and plagiarism in online English education including a comparison between online and face to face academic dishonesty, reasons students cheat or plagiarize in online education and attitudes toward academic dishonesty, how students cheat and plagiarize in online classes, how teachers detect academic dishonesty in their online classes, consequences and policies of academic dishonesty in online education, and preventing academic dishonesty in online education. The overall new finding, from comparing both the literature review and the FLVS survey results, was that academic dishonesty in online education is not vastly different from academic dishonesty in face to face classrooms; therefore, academic dishonesty in the online environment is not as much of a mystery as commonly perceived. The survey did, however, expand the knowledge about online academic dishonesty at the secondary level, and specifically in the English Language Arts content area.
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Date Issued
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2012
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Identifier
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CFH0004158, ucf:44859
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFH0004158
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Title
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IMPROVED PHYSIOLOGY AND PSYCHOSOCIAL WELL-BEING FOR CHILDREN WITH PHYSICAL DISABILITIES THROUGH VIRTUAL REALITY IMMERSION.
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Creator
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Fralish, Bethany D, Nickels, Megan, University of Central Florida
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Abstract / Description
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The purpose of this case study was to examine the physiological and psychosocial effects of an immersive virtual reality (VR) system in a female, young adult with right side paralysis following a left hemisphere brain bleed in order to determine the usefulness of immersive VR for children with physical disabilities, in particular, cerebral palsy (CP). The current study consisted of six sessions over a span of three weeks, with each session lasting approximately 45 minutes. Physiological...
Show moreThe purpose of this case study was to examine the physiological and psychosocial effects of an immersive virtual reality (VR) system in a female, young adult with right side paralysis following a left hemisphere brain bleed in order to determine the usefulness of immersive VR for children with physical disabilities, in particular, cerebral palsy (CP). The current study consisted of six sessions over a span of three weeks, with each session lasting approximately 45 minutes. Physiological factors (upper body mobility, heart rate variability) were assessed via a hand use questionnaire and a heart rate monitor, while psychosocial factors (e.g. positive mood) were assessed through post-session debriefing discussions with the participant. All measures were completed at each of the six VR sessions, with the exception of the hand use questionnaire, which was administered at baseline, and post-intervention. The VR programs selected were specifically chosen to engage upper body and arm movements. Descriptive analyses and coding of interviews were conducted to examine changes throughout the study sessions. The participant reported an increase in hand mobility and psychosocial well-being, such as improvement in mood, as a result of her participation in the VR sessions. The results of the current study suggest that the use of movement-specific VR programs may be beneficial to children with physical disabilities and CP, although due to the single-subject design of the study, further research is warranted.
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Date Issued
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2017
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Identifier
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CFH2000255, ucf:46028
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFH2000255
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Title
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AFFORDANCES IN THE DESIGN OF VIRTUAL ENVIRONMENTS.
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Creator
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Gross, David Charles, 4., Stannry, Kay M., University of Central Florida
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Abstract / Description
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Human-computer interaction design principles largely focus on static representations and have yet to fully incorporate theories of perception appropriate for the dynamic multimodal interactions inherent to virtual environment (VE) interaction. Theories of direct perception, in particular affordance theory, may prove particularly relevant to enhancing VE interaction design. The present research constructs a conceptual model of how affordances are realized in the natural world and how lack of...
Show moreHuman-computer interaction design principles largely focus on static representations and have yet to fully incorporate theories of perception appropriate for the dynamic multimodal interactions inherent to virtual environment (VE) interaction. Theories of direct perception, in particular affordance theory, may prove particularly relevant to enhancing VE interaction design. The present research constructs a conceptual model of how affordances are realized in the natural world and how lack of sensory stimuli may lead to realization failures in virtual environments. Implications of the model were empirically investigated by examining three affordances: passability, catchability, and flyability. The experimental design involved four factors for each of the three affordances and was implemented as a fractional factorial design. The results demonstrated that providing affording cues led to behavior closely in-line with real-world behavior. More specifically, when given affording cues participants tended to rotate their virtual bodies when entering narrow passageways, accurately judge balls as catchable, and fly when conditions warranted it. The results support the conceptual model and demonstrate 1) that substituting designed cues via sensory stimuli in available sensory modalities for absent or impoverished modalities may enable the perception of affordances in VEs; 2) that sensory stimuli substitutions provide potential approaches for enabling the perception of affordances in a VE which in the real world are cross-modal; and 3) that affordances relating to specific action capabilities may be enabled by designed sensory stimuli. This research lays an empirical foundation for a science of VE design based on choosing and implementing design properties so as to evoke targeted user behavior
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Date Issued
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2004
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Identifier
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CFE0000061, ucf:46108
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0000061
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Title
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DOUBLE DUTY: PROCESSING AND EXHIBITING THE CHILDREN'S HOME SOCIETY OF FLORIDA COLLECTION AS AN ARCHIVIST AND PUBLIC HISTORIAN.
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Creator
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Anderson, April, White, Vibert, University of Central Florida
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Abstract / Description
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The Children's Home Society of Florida, often referred to as "Florida's Greatest Charity", is the state's oldest non profit welfare agency. Founded in 1902, the society was instrumental in creating and reforming child welfare laws as well as helping countless children in the state of Florida find loving homes. This paper focuses on the archival processing of the Children's Home Society of Florida Collection papers and the creation of a subsequent web exhibit. The role of...
Show moreThe Children's Home Society of Florida, often referred to as "Florida's Greatest Charity", is the state's oldest non profit welfare agency. Founded in 1902, the society was instrumental in creating and reforming child welfare laws as well as helping countless children in the state of Florida find loving homes. This paper focuses on the archival processing of the Children's Home Society of Florida Collection papers and the creation of a subsequent web exhibit. The role of archivist and public historian is examined to see how each profession works toward a common goal.
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Date Issued
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2007
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Identifier
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CFE0001613, ucf:47181
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0001613
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Title
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VIRTUAL VISTAS: HIGH SCHOOL STUDENTS DESCRIBING THEIR EXPERIENCES IN ONLINE COURSES.
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Creator
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Scheick, Amy, Gunter, Glenda, University of Central Florida
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Abstract / Description
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Current research indicates that distance education courses can be as effective as traditional courses when the method and technologies used are appropriate to the instructional tasks. The number of states, counties, and school districts that provide online courses for high school students has rapidly expanded during the last ten years. The number of students, who enroll in these courses, has often grown by double digits each year. Understanding K-12 students' experiences in, and...
Show moreCurrent research indicates that distance education courses can be as effective as traditional courses when the method and technologies used are appropriate to the instructional tasks. The number of states, counties, and school districts that provide online courses for high school students has rapidly expanded during the last ten years. The number of students, who enroll in these courses, has often grown by double digits each year. Understanding K-12 students' experiences in, and expectations of, online learning is important for many reasons. Online learning is certainly growing and may become a graduation requirement in more states. Currently Michigan requires every student must participate in some form of online learning as a high school graduation requirement. High school students enrolling in online courses may have a measurable influence on higher education courses in the future, as students become more experienced with online learning. A great deal has been written about the development of virtual high schools, some of the issues surrounding them and basic student demographics. There are only a few studies that have interviewed students in detail as to why they have chosen to participate in a virtual school and examined how this choice has impacted them. The purpose of this study was to describe from the student's perspective, why they had enrolled in online courses and allowed them to characterize their experiences. Further, this study sought to identify the personality types and traits of the students enrolled in online high school courses and reported on one measure of the student's cognitive style or cognitive tempo. Forty-three students who were enrolled in a state sponsored virtual high school participated in this study. The study used three online instruments to collect data. The Matching Familiar Figures Test-20 was used to measure the impulsive or reflective responses of the students. The Long-Dziuban Reactive Behavioral Survey was used to determine the students' personality types. The third instrument was an online questionnaire of open-ended questions asking the students about their online experiences. In addition, twelve students participated in follow-up interviews. The study found that the students enrolled in online courses for a variety of reasons; students were concerned about and wanted control over the timing and pacing of their learning. Students' comments suggested that there may be a relationship between cognitive tempo as classified by the MFFT-20, and the students' preference for pacing through the online course materials. In addition, the distribution of personality types and cognitive styles represented in this sample were different from the general school population suggesting that perhaps some students are more interested in online learning than others are. After reviewing the results of the students responses to the MFFT-20, it may be that students may are becoming faster at processing visual information with fewer errors. More research is needed in this area. There does seem to be a trend in this direction and this could have implications for students enrolled in virtual high school courses. Finally, the students in this study characterized their online learning experiences as positive but did not feel that online learning should be a high school graduation requirement for all students.
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Date Issued
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2007
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Identifier
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CFE0001674, ucf:47213
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0001674
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Title
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STUDY FOR DEVELOPMENT OF A BLAST LAYER FOR THE VIRTUAL RANGE PROJECT.
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Creator
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Rosales, Sergio, Sepulveda, Jose, University of Central Florida
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Abstract / Description
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In this work we develop a Blast-Propellant-Facility integrated analysis study, which evaluates, by using two different approaches, the blast-related impact of an explosive accident of the Space Shuttle during the first ten seconds after launch at Kennedy Space Center. The blast-related risk associated with an explosion at this stage is high because of the quantity of energy involved in both multiple and complex processes. To do this, one of our approaches employed BlastFX®, a software...
Show moreIn this work we develop a Blast-Propellant-Facility integrated analysis study, which evaluates, by using two different approaches, the blast-related impact of an explosive accident of the Space Shuttle during the first ten seconds after launch at Kennedy Space Center. The blast-related risk associated with an explosion at this stage is high because of the quantity of energy involved in both multiple and complex processes. To do this, one of our approaches employed BlastFX®, a software system that facilitates the estimation of the level of damage to people and buildings, starting from an explosive device and rendering results through a complete report that illustrates and facilitates the evaluation of consequences. Our other approaches employed the Hopkinson-Cranz Scaled Law for estimating similar features at a more distant distance and by evaluating bigger amounts of TNT equivalent. Specifically, we considered more than 500 m and 45,400 kg, respectively, which are the range and TNT content limits that our version of BlastFX® can cover. Much research has been done to study the explosion phenomena with respect to both solid and liquid propellants and the laws that underlie the blast waves of an explosion. Therefore our methodology is based on the foundation provided by a large set of literature review and the actual capacities of an application like BlastFX®. By using and integrating the lessons from the literature and the capabilities of the software, we have obtained very useful information for evaluating different scenarios that rely on the assumption, which is largely studied, that the blast waves' behavior is affected by the distance. All of this has been focused on the Space Shuttle system, in which propellant mass represents the source of our analysis and the core of this work. Estimating the risks involved in it and providing results based on different scenarios augments the collective knowledge of risks associated with space exploration.
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Date Issued
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2004
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Identifier
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CFE0000190, ucf:46171
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0000190
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Title
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OFF-CHIP COMMUNICATIONS ARCHITECTURES FOR HIGH THROUGHPUT NETWORK PROCESSORS.
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Creator
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Engel, Jacob, Kocak, Taskin, University of Central Florida
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Abstract / Description
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In this work, we present off-chip communications architectures for line cards to increase the throughput of the currently used memory system. In recent years there is a significant increase in memory bandwidth demand on line cards as a result of higher line rates, an increase in deep packet inspection operations and an unstoppable expansion in lookup tables. As line-rate data and NPU processing power increase, memory access time becomes the main system bottleneck during data store/retrieve...
Show moreIn this work, we present off-chip communications architectures for line cards to increase the throughput of the currently used memory system. In recent years there is a significant increase in memory bandwidth demand on line cards as a result of higher line rates, an increase in deep packet inspection operations and an unstoppable expansion in lookup tables. As line-rate data and NPU processing power increase, memory access time becomes the main system bottleneck during data store/retrieve operations. The growing demand for memory bandwidth contrasts the notion of indirect interconnect methodologies. Moreover, solutions to the memory bandwidth bottleneck are limited by physical constraints such as area and NPU I/O pins. Therefore, indirect interconnects are replaced with direct, packet-based networks such as mesh, torus or k-ary n-cubes. We investigate multiple k-ary n-cube based interconnects and propose two variations of 2-ary 3-cube interconnect called the 3D-bus and 3D-mesh. All of the k-ary n-cube interconnects include multiple, highly efficient techniques to route, switch, and control packet flows in order to minimize congestion spots and packet loss. We explore the tradeoffs between implementation constraints and performance. We also developed an event-driven, interconnect simulation framework to evaluate the performance of packet-based off-chip k-ary n-cube interconnect architectures for line cards. The simulator uses the state-of-the-art software design techniques to provide the user with a flexible yet robust tool, that can emulate multiple interconnect architectures under non-uniform traffic patterns. Moreover, the simulator offers the user with full control over network parameters, performance enhancing features and simulation time frames that make the platform as identical as possible to the real line card physical and functional properties. By using our network simulator, we reveal the best processor-memory configuration, out of multiple configurations, that achieves optimal performance. Moreover, we explore how network enhancement techniques such as virtual channels and sub-channeling improve network latency and throughput. Our performance results show that k-ary n-cube topologies, and especially our modified version of 2-ary 3-cube interconnect - the 3D-mesh, significantly outperform existing line card interconnects and are able to sustain higher traffic loads. The flow control mechanism proved to extensively reduce hot-spots, load-balance areas of high traffic rate and achieve low transmission failure rate. Moreover, it can scale to adopt more memories and/or processors and as a result to increase the line card's processing power.
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Date Issued
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2005
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Identifier
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CFE0000734, ucf:46581
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0000734
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Title
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DIRECT MANIPULATION OF VIRTUAL OBJECTS.
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Creator
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Nguyen, Long, Malone, Linda, University of Central Florida
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Abstract / Description
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Interacting with a Virtual Environment (VE) generally requires the user to correctly perceive the relative position and orientation of virtual objects. For applications requiring interaction in personal space, the user may also need to accurately judge the position of the virtual object relative to that of a real object, for example, a virtual button and the user's real hand. This is difficult since VEs generally only provide a subset of the cues experienced in the real world....
Show moreInteracting with a Virtual Environment (VE) generally requires the user to correctly perceive the relative position and orientation of virtual objects. For applications requiring interaction in personal space, the user may also need to accurately judge the position of the virtual object relative to that of a real object, for example, a virtual button and the user's real hand. This is difficult since VEs generally only provide a subset of the cues experienced in the real world. Complicating matters further, VEs presented by currently available visual displays may be inaccurate or distorted due to technological limitations. Fundamental physiological and psychological aspects of vision as they pertain to the task of object manipulation were thoroughly reviewed. Other sensory modalities proprioception, haptics, and audition and their cross-interactions with each other and with vision are briefly discussed. Visual display technologies, the primary component of any VE, were canvassed and compared. Current applications and research were gathered and categorized by different VE types and object interaction techniques. While object interaction research abounds in the literature, pockets of research gaps remain. Direct, dexterous, manual interaction with virtual objects in Mixed Reality (MR), where the real, seen hand accurately and effectively interacts with virtual objects, has not yet been fully quantified. An experimental test bed was designed to provide the highest accuracy attainable for salient visual cues in personal space. Optical alignment and user calibration were carefully performed. The test bed accommodated the full continuum of VE types and sensory modalities for comprehensive comparison studies. Experimental designs included two sets, each measuring depth perception and object interaction. The first set addressed the extreme end points of the Reality-Virtuality (R-V) continuum Immersive Virtual Environment (IVE) and Reality Environment (RE). This validated, linked, and extended several previous research findings, using one common test bed and participant pool. The results provided a proven method and solid reference points for further research. The second set of experiments leveraged the first to explore the full R-V spectrum and included additional, relevant sensory modalities. It consisted of two full-factorial experiments providing for rich data and key insights into the effect of each type of environment and each modality on accuracy and timeliness of virtual object interaction. The empirical results clearly showed that mean depth perception error in personal space was less than four millimeters whether the stimuli presented were real, virtual, or mixed. Likewise, mean error for the simple task of pushing a button was less than four millimeters whether the button was real or virtual. Mean task completion time was less than one second. Key to the high accuracy and quick task performance time observed was the correct presentation of the visual cues, including occlusion, stereoscopy, accommodation, and convergence. With performance results already near optimal level with accurate visual cues presented, adding proprioception, audio, and haptic cues did not significantly improve performance. Recommendations for future research include enhancement of the visual display and further experiments with more complex tasks and additional control variables.
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Date Issued
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2009
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Identifier
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CFE0002822, ucf:48060
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0002822
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Title
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Comparative Analysis of The Effects Of Virtual Reality Active Video Game And Controller-Free Active Video Game Play On Physiological Response, Perceived Exertion, And Hedonic Experience.
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Creator
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Wooden, Shanon, McCauley, Pamela, Rabelo, Luis, Karwowski, Waldemar, Fukuda, David, University of Central Florida
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Abstract / Description
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Over 60% of US adults are overweight or obese. Sedentary lifestyles are considered major contributors to the high rates and increasing prevalence of obesity. Physical activity is a critical component in shifting from sedentary lifestyles. Studies indicate that less than half of U.S. adults meet the CDC/ACSM physical activity recommendations. Interactive video games can increase PA, but no study has yet assessed physiologic effort, hedonics, and perceived exertion for playing immersive virtual...
Show moreOver 60% of US adults are overweight or obese. Sedentary lifestyles are considered major contributors to the high rates and increasing prevalence of obesity. Physical activity is a critical component in shifting from sedentary lifestyles. Studies indicate that less than half of U.S. adults meet the CDC/ACSM physical activity recommendations. Interactive video games can increase PA, but no study has yet assessed physiologic effort, hedonics, and perceived exertion for playing immersive virtual reality (VR) and controller-free screen-based active video games (AVGs), compared to treadmill walking and resting. We ran 25 subjects (9 female, 16 male) in 10-minute sessions of five conditions. Head Mounted Display VR: Oculus (Fruit Ninja and Boxing), Screen-based AVG: Kinect (Fruit Ninja and Boxing), and Treadmill walking at 3 mph. One, six-condition (Rest, Treadmill 3.0, Kinect Boxing, Kinect Fruit Ninja, Oculus Boxing, Oculus Fruit Ninja) repeated-measures ANOVA was used to examine differences in HRmean. Three, five-condition (Treadmill 3.0, Kinect Boxing, Kinect Fruit Ninja, Oculus Boxing, Oculus Fruit Ninja) repeated-measures ANOVA were used to examine differences in HRpeak, ratings of perceived exertion (RPE) and Hedonics (Liking). Post hoc analyses using pairwise comparisons were used to further assess significant main effects of the condition. A Pearson's product-moment correlation was run to assess the relationship between activity condition HRmean and RPE VR Boxing elicited the greatest physiological effort, producing vigorous-intensity PA. There was no significant difference in average heart rate for the Treadmill, Kinect Fruit Ninja, Kinect Boxing, and VR Fruit Ninja. Thus, the Kinect and VR sport and casual games are comparable to treadmill walking PA levels and qualify as moderate-intensity activity. The VR Fruit Ninja, VR Boxing, Kinect Fruit Ninja were the most enjoyed activities. Despite having the highest Heart rate and the highest self-reported Rating of Perceived Exertion (RPE), VR Boxing was significantly more enjoyable than Treadmill Walking. There was no statistically significant correlation between Activity Condition HRmean and RPE.Both casual and sports VR and AVG activities are enjoyable activities for adults, stimulating moderate-to-vigorous activity through a traditionally sedentary medium. This research extends previous works in active video gaming effects on physiological cost, perceived exertion and hedonics and fills the gap relating virtual reality active video games. The significance of the research outcomes is that this analysis provides a scientifically validated approach to support the establishment of physical activity level goals and guidelines in the development of active video games as a response and/or remedy to address the sedentary lifestyles that are contributing to American and global obesity.
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Date Issued
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2018
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Identifier
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CFE0007383, ucf:52065
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0007383
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Title
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Narrative Transportation and Virtual Reality: Exploring the Immersive Qualities of Social Justice in the Digital World.
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Creator
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Raffel, Sara, McDaniel, Rudy, Jones, Natasha, Salter, Anastasia, Rettberg, Jill, University of Central Florida
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Abstract / Description
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This dissertation explores the potential applications for virtual reality (VR) stories in support of social justice causes, examining whether digital games historically been successfully leveraged for social justice purposes, and determining which components of VR technology can most encourage narrative transportation of participants in VR stories.The first chapter examines theories of simulation, virtual reality, narrative, and interactivity, as well as concepts of immersion from various...
Show moreThis dissertation explores the potential applications for virtual reality (VR) stories in support of social justice causes, examining whether digital games historically been successfully leveraged for social justice purposes, and determining which components of VR technology can most encourage narrative transportation of participants in VR stories.The first chapter examines theories of simulation, virtual reality, narrative, and interactivity, as well as concepts of immersion from various disciplines and settles on narrative transportation, a theory from cognitive psychology, as the most useful in measuring the effect of VR stories on participants.The second chapter examines ethnographic practices, activist games, and modes of reclaiming digital spaces as a way to encourage digital social justice and ensure traditionally marginalized communities have meaningful access to technology(-)or, the tools to use it, create with it, and critique it.The third chapter presents the result of a play study conducted to measure participants' transportation in a recent VR narrative and finds VR interactive narratives to be more transportive and engaging than their two-dimensional counterparts.The fourth chapter interrogates some of the fears of VR technology, namely that it will be used to further current societal injustices and as a potentially powerful propaganda tool.The final chapter presents five recommendations for designers seeking to experiment in virtual reality narratives. The ultimate aim of this work is to encourage scholars, designers, and participants to make ethical decisions in the creation and use of virtual societies.
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Date Issued
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2018
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Identifier
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CFE0007080, ucf:52015
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0007080
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Title
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Game-Theoretic Frameworks and Strategies for Defense Against Network Jamming and Collocation Attacks.
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Creator
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Hemida, Ahmed, Atia, George, Simaan, Marwan, Vosoughi, Azadeh, Sukthankar, Gita, Guirguis, Mina, University of Central Florida
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Abstract / Description
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Modern networks are becoming increasingly more complex, heterogeneous, and densely connected. While more diverse services are enabled to an ever-increasing number of users through ubiquitous networking and pervasive computing, several important challenges have emerged. For example, densely connected networks are prone to higher levels of interference, which makes them more vulnerable to jamming attacks. Also, the utilization of software-based protocols to perform routing, load balancing and...
Show moreModern networks are becoming increasingly more complex, heterogeneous, and densely connected. While more diverse services are enabled to an ever-increasing number of users through ubiquitous networking and pervasive computing, several important challenges have emerged. For example, densely connected networks are prone to higher levels of interference, which makes them more vulnerable to jamming attacks. Also, the utilization of software-based protocols to perform routing, load balancing and power management functions in Software-Defined Networks gives rise to more vulnerabilities that could be exploited by malicious users and adversaries. Moreover, the increased reliance on cloud computing services due to a growing demand for communication and computation resources poses formidable security challenges due to the shared nature and virtualization of cloud computing. In this thesis, we study two types of attacks: jamming attacks on wireless networks and side-channel attacks on cloud computing servers. The former attacks disrupt the natural network operation by exploiting the static topology and dynamic channel assignment in wireless networks, while the latter attacks seek to gain access to unauthorized data by co-residing with target virtual machines (VMs) on the same physical node in a cloud server. In both attacks, the adversary faces a static attack surface and achieves her illegitimate goal by exploiting a stationary aspect of the network functionality. Hence, this dissertation proposes and develops counter approaches to both attacks using moving target defense strategies. We study the strategic interactions between the adversary and the network administrator within a game-theoretic framework.First, in the context of jamming attacks, we present and analyze a game-theoretic formulation between the adversary and the network defender. In this problem, the attack surface is the network connectivity (the static topology) as the adversary jams a subset of nodes to increase the level of interference in the network. On the other side, the defender makes judicious adjustments of the transmission footprint of the various nodes, thereby continuously adapting the underlying network topology to reduce the impact of the attack. The defender's strategy is based on playing Nash equilibrium strategies securing a worst-case network utility. Moreover, scalable decomposition-based approaches are developed yielding a scalable defense strategy whose performance closely approaches that of the non-decomposed game for large-scale and dense networks. We study a class of games considering discrete as well as continuous power levels.In the second problem, we consider multi-tenant clouds, where a number of VMs are typically collocated on the same physical machine to optimize performance and power consumption and maximize profit. This increases the risk of a malicious virtual machine performing side-channel attacks and leaking sensitive information from neighboring VMs. The attack surface, in this case, is the static residency of VMs on a set of physical nodes, hence we develop a timed migration defense approach. Specifically, we analyze a timing game in which the cloud provider decides when to migrate a VM to a different physical machine to mitigate the risk of being compromised by a collocated malicious VM. The adversary decides the rate at which she launches new VMs to collocate with the victim VMs. Our formulation captures a data leakage model in which the cost incurred by the cloud provider depends on the duration of collocation with malicious VMs. It also captures costs incurred by the adversary in launching new VMs and by the defender in migrating VMs. We establish sufficient conditions for the existence of Nash equilibria for general cost functions, as well as for specific instantiations, and characterize the best response for both players. Furthermore, we extend our model to characterize its impact on the attacker's payoff when the cloud utilizes intrusion detection systems that detect side-channel attacks. Our theoretical findings are corroborated with extensive numerical results in various settings as well as a proof-of-concept implementation in a realistic cloud setting.
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Date Issued
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2019
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Identifier
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CFE0007468, ucf:52677
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0007468
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Title
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Vision-Based Testbeds for Control System Applicaitons.
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Creator
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Sivilli, Robert, Xu, Yunjun, Gou, Jihua, Cho, Hyoung, Pham, Khanh, University of Central Florida
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Abstract / Description
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In the field of control systems, testbeds are a pivotal step in the validation and improvement of new algorithms for different applications. They provide a safe, controlled environment typically having a significantly lower cost of failure than the final application. Vision systems provide nonintrusive methods of measurement that can be easily implemented for various setups and applications. This work presents methods for modeling, removing distortion, calibrating, and rectifying single and...
Show moreIn the field of control systems, testbeds are a pivotal step in the validation and improvement of new algorithms for different applications. They provide a safe, controlled environment typically having a significantly lower cost of failure than the final application. Vision systems provide nonintrusive methods of measurement that can be easily implemented for various setups and applications. This work presents methods for modeling, removing distortion, calibrating, and rectifying single and two camera systems, as well as, two very different applications of vision-based control system testbeds: deflection control of shape memory polymers and trajectory planning for mobile robots. First, a testbed for the modeling and control of shape memory polymers (SMP) is designed. Red-green-blue (RGB) thresholding is used to assist in the webcam-based, 3D reconstruction of points of interest. A PID based controller is designed and shown to work with SMP samples, while state space models were identified from step input responses. Models were used to develop a linear quadratic regulator that is shown to work in simulation. Also, a simple to use graphical interface is designed for fast and simple testing of a series of samples. Second, a robot testbed is designed to test new trajectory planning algorithms. A template-based predictive search algorithm is investigated to process the images obtained through a low-cost webcam vision system, which is used to monitor the testbed environment. Also a user-friendly graphical interface is developed such that the functionalities of the webcam, robots, and optimizations are automated. The testbeds are used to demonstrate a wavefront-enhanced, B-spline augmented virtual motion camouflage algorithm for single or multiple robots to navigate through an obstacle dense and changing environment, while considering inter-vehicle conflicts, obstacle avoidance, nonlinear dynamics, and different constraints. In addition, it is expected that this testbed can be used to test different vehicle motion planning and control algorithms.
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Date Issued
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2012
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Identifier
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CFE0004601, ucf:49187
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0004601
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Title
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Optimal Attitude Control Management for a Cubesat.
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Creator
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Develle, Michael, Xu, Yunjun, Lin, Kuo-Chi, Chew, Phyekeng, University of Central Florida
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Abstract / Description
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CubeSats have become popular among universities, research organizations, and government agencies due to their low cost, small size, and light weight. Their standardized configurations further reduce the development time and ensure more frequent launch opportunities. Early cubesat missions focused on hardware validation and simple communication missions, with little requirement for pointing accuracy. Most of these used magnetic torque rods or coils for attitude stabilization. However, the...
Show moreCubeSats have become popular among universities, research organizations, and government agencies due to their low cost, small size, and light weight. Their standardized configurations further reduce the development time and ensure more frequent launch opportunities. Early cubesat missions focused on hardware validation and simple communication missions, with little requirement for pointing accuracy. Most of these used magnetic torque rods or coils for attitude stabilization. However, the intrinsic problems associated with magnetictorque systems, such as the lack of three-axis control and low pointing accuracy, make them unsuitable for more advanced missions such as detailed imaging and on-orbit inspection. Three-axis control in a cubesat can be achieved by combining magnetic torque coils with other devices such as thrusters, but the lifetime is limited by the fuel source onboard. To maximize the missionlifetime, a fast attitude control management algorithm that could optimally manage the usage of the magnetic and thruster torques is desirable. Therefore, a recently developed method, the B-Spline-augmented virtual motion camouflage, is presented in this defense to solve the problem. This approach provides results which are very close to those obtained through other popular nonlinear constrained optimal control methods with a significantly reduced computational time.Simulation results are presented to validate the capabilities of the method in this application.
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Date Issued
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2011
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Identifier
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CFE0004099, ucf:49102
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0004099
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Title
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Human Group Behavior Modeling for Virtual Worlds.
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Creator
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Shah, Syed Fahad Allam, Sukthankar, Gita, Georgiopoulos, Michael, Foroosh, Hassan, Anagnostopoulos, Georgios, University of Central Florida
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Abstract / Description
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Virtual worlds and massively-multiplayer online games are rich sources of information about large-scale teams and groups, offering the tantalizing possibility of harvesting data about group formation, social networks, and network evolution. They provide new outlets for human social interaction that differ from both face-to-face interactions and non-physically-embodied social networking tools such as Facebook and Twitter. We aim to study group dynamics in these virtual worlds by collecting and...
Show moreVirtual worlds and massively-multiplayer online games are rich sources of information about large-scale teams and groups, offering the tantalizing possibility of harvesting data about group formation, social networks, and network evolution. They provide new outlets for human social interaction that differ from both face-to-face interactions and non-physically-embodied social networking tools such as Facebook and Twitter. We aim to study group dynamics in these virtual worlds by collecting and analyzing public conversational patterns of users grouped in close physical proximity. To do this, we created a set of tools for monitoring, partitioning, and analyzing unstructured conversations between changing groups of participants in Second Life, a massively multi-player online user-constructed environment that allows users to construct and inhabit their own 3D world. Although there are some cues in the dialog, determining social interactions from unstructured chat data alone is a difficult problem, since these environments lack many of the cues that facilitate natural language processing in other conversational settings and different types of social media. Public chat data often features players who speak simultaneously, use jargon and emoticons, and only erratically adhere to conversational norms.Humans are adept social animals capable of identifying friendship groups from a combination of linguistic cues and social network patterns. But what is more important, the content of what people say or their history of social interactions? Moreover, is it possible to identify whether people are part of a group with changing membership merely from general network properties, such as measures of centrality and latent communities? These are the questions that we aim to answer in this thesis. The contributions of this thesis include: 1) a link prediction algorithm for identifying friendship relationships from unstructured chat data 2) a method for identifying social groups based on the results of community detection and topic analysis.The output of these two algorithms (links and group membership) are useful for studying a variety of research questions about human behavior in virtual worlds. To demonstrate this we have performed a longitudinal analysis of human groups in different regions of the Second Life virtual world. We believe that studies performed with our tools in virtual worlds will be a useful stepping stone toward creating a rich computational model of human group dynamics.
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Date Issued
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2011
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Identifier
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CFE0004164, ucf:49074
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0004164
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Title
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FIELD OF VIEW EFFECTS ON REFLEXIVE MOTOR RESPONSEIN FLIGHT SIMULATION.
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Creator
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Covelli, Javier, Rolland, Jannick, University of Central Florida
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Abstract / Description
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Virtual Reality (VR) and Augmented Reality (AR) Head Mounted Display (HMD) or Head Worn Display (HWD) technology represents low-cost, wide Field of Regard (FOR), deployable systems when compared to traditional simulation facilities. However, given current technological limitations, HWD flight simulator implementations provide a limited effective Field of View (eFOV) far narrower than the normal human 200º horizontal and 135º vertical FOV. Developing a HWD with such a wide FOV is...
Show moreVirtual Reality (VR) and Augmented Reality (AR) Head Mounted Display (HMD) or Head Worn Display (HWD) technology represents low-cost, wide Field of Regard (FOR), deployable systems when compared to traditional simulation facilities. However, given current technological limitations, HWD flight simulator implementations provide a limited effective Field of View (eFOV) far narrower than the normal human 200º horizontal and 135º vertical FOV. Developing a HWD with such a wide FOV is expensive but can increase the aviator's visual stimulus, perception, sense of presence and overall training effectiveness. This research and experimentation test this proposition by manipulating the eFOV of experienced pilots in a flight simulator while measuring their reflexive motor response and task performance. Reflexive motor responses are categorized as information, importance and effort behaviors. Performance metrics taken include runway alignment error (RAE) and vertical track error (VTE). Results indicated a significant and systematic change in visual scan pattern, head movement and flight control performance as the eFOV was sequentially decreased. As FOV decreased, the average visual scan pattern changed to focus less on out-the-window (OTW) and more on the instruments inside the cockpit. The head range of movement significantly increased below 80º horizontal x 54º vertical eFOV as well as significantly decreasing runway alignment and vertical track performance, which occurred below 120° horizontal x 81° vertical eFOV.
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Date Issued
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2008
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Identifier
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CFE0002002, ucf:47617
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0002002
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Title
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TESTING THE IMPACT OF TRAINING WITH SIMULATED SCENARIOS FOR INFORMATION SECURITY AWARENESS ON VIRTUAL COMMUNITY OF PRACTICE MEMBERS.
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Creator
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Tidwell, Craig, Reilly, Charles, University of Central Florida
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Abstract / Description
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Information security has become a major challenge for all private and public organizations. The protection of proprietary and secret data and the proper awareness of what is entailed in protecting this data are necessary in all organizations. This treatise examines how simulation and training would influence information security awareness over time in virtual communities of practice under a variety of security threats. The hypothesis of the study was that security-trained members of a virtual...
Show moreInformation security has become a major challenge for all private and public organizations. The protection of proprietary and secret data and the proper awareness of what is entailed in protecting this data are necessary in all organizations. This treatise examines how simulation and training would influence information security awareness over time in virtual communities of practice under a variety of security threats. The hypothesis of the study was that security-trained members of a virtual community of practice would respond significantly better to routine security processes and attempts to breach security or to violate the security policy of their organization or of their virtual community of practice. Deterrence theory was used as the grounded theory and integrated in the information security awareness training with simulated scenarios. The study provided training with simulated scenarios and then tested the users of a virtual community of practice over an approximately twelve-week period to see if the planned security awareness training with simulated security problem scenarios would be effective in improving their responses to the follow-up tests. The research subjects were divided into four groups, the experimental group and three control groups. The experimental group received all of the training and testing events throughout the twelve-week period. The three control groups received various portions of the training and testing. The data from all of the tests were analyzed using the Kruskal-Wallis ranked order test, and it was determined that there was no significant difference between the groups at the end of the data collection. Even though the null hypothesis, which stated that there would be no difference between the groups scores on the information security awareness tests, was not rejected, the groups that received the initial training with the simulated scenarios did perform slightly better from the pre-training test to the post-training test when compared with the control group that did not receive the initial training. More research is suggested to determine how information security awareness training with simulated scenarios and follow-up testing can be used to improve and sustain the security practices of members of virtual communities of practice. Specifically, additional research could include: comparing the effect of training with the simulated scenarios and with training that would not use the simulated security scenarios; the potential benefits of using adaptive and intelligent training to focus on the individual subjects' weaknesses and strengths; the length of the training with simulated scenarios events, the time between each training event, and the overall length of the training; the demographics of the groups used in the training, and how different user characteristics impact the efficacy of the training with simulated scenarios and testing; and lastly examining how increasing the fidelity of the simulated scenarios might impact the results of the follow-up tests.
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Date Issued
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2011
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Identifier
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CFE0003566, ucf:48923
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0003566
Pages