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Title: Composing the Classroom, Constructing Hybridity: Writing Technology in(to) First-Year Composition Course Design.
Creator: Friend, Christopher, Vie, Stephanie, Wardle, Elizabeth, Scott, Blake, Stommel, Jesse, University of Central Florida
Abstract / Description: Online education has received excessive attention in recent decades as its characteristics and potential have undergone intense debate and scrutiny. Similar debate and scrutiny surround the content of first-year composition (FYC) courses. As we continue to define what composition studies entails, we redefine what we study in FYC. Yet discussions of blended delivery mode---using both online and on-ground teaching methods---get lost amid these debates. This dissertation addresses the dearth of...
Show moreOnline education has received excessive attention in recent decades as its characteristics and potential have undergone intense debate and scrutiny. Similar debate and scrutiny surround the content of first-year composition (FYC) courses. As we continue to define what composition studies entails, we redefine what we study in FYC. Yet discussions of blended delivery mode---using both online and on-ground teaching methods---get lost amid these debates. This dissertation addresses the dearth of research on blended online writing instruction by asserting the essential nature of connections between the content and the delivery of FYC courses.Through case studies of two experienced instructors teaching FYC in a blended environment for the first time, this dissertation evaluates the composition(-)both as a noun and as a verb(-)of FYC courses in light of the technology involved. Through an analysis of interviews with instructors, students, and faculty involved with FYC, I highlight the points of contact(-)the interfaces(-)that themselves create the experience of a class. This analysis applies interface theory from rhetoric and composition to the pedagogical acts of teaching FYC and reveals how attention to classroom interfaces can benefit our pedagogy.This project also incorporates student performance data (in the form of portfolio evaluations), student perception data (in the form of surveys), and comparative institutional data (in the form of website analysis) to better understand the varied causes, effects, and implementations of blended learning. By looking outside the classroom environment, I show how schools influence the way blended courses are perceived by those who create them. The differences in student and instructor expectations for this kind of class emerged as particularly influential in determining how successful a blended course can be.The perspective taken by an instructor in terms of experience and expertise also emerged as a significant determinant of perceived success, particularly for instructors themselves. This dissertation reveals the delicate balance instructors must navigate between relying on expertise in the field and exploring the course delivery as a novice. This balance allows instructors to be responsive, flexible, and dynamic in their classes while also assisting students in their efforts to better understand FYC course content.Overall, this dissertation defines and advocates for a hybrid approach to FYC instruction as an essential evolution of our pedagogical praxis. Students lead increasingly hybrid lives and learn in increasingly hybrid ways. Instructors must adopt hybridity in their classes to accommodate not only students' changing learning styles but also the changing nature of composition as a field and writing as its subject matter. And finally, institutions must consistently define and implement principles of hybridity to help reduce confusion and frustration across the disciplines. Suggestions for educators and institutions alike are provided to help meet the needs of today's students.
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Date Issued: 2014
Identifier: CFE0005332, ucf:50541
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005332

Title: DESIGN CONCEPT: MY AMALGAMATION OF EASTERN AND WESTERN CULTURES.
Creator: Dong, Yuting, Hall, Scott, University of Central Florida
Abstract / Description: While exploring various subjects in multiple techniques in multiple mediums, I create abstract images that illustrate high technology, urban life, and personal feelings. My work is influenced by Eastern and Western culture. Media, publication, and fashion are derived from Western culture, and design elements are derived from Eastern culture. In doing this, my goal is to achieve more opportunities, greater depth, and a wider audience for my work by cross-utilizing these diverse culture aspects.
Date Issued: 2008
Identifier: CFE0002097, ucf:47542
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0002097

Title: Chemistry and(&)nbsp;Structure of Ru/SiO2(&)nbsp;and Ru/Al2O3 Interfaces.
Creator: Ezzat, Sameer, Campiglia, Andres, Coffey, Kevin, Zou, Shengli, Frazer, Andrew, Harper, James, Coffey, Kevin, University of Central Florida
Abstract / Description: The resistivity size effect in nanoscale metals is of both scientific and technological interest, the latter due to its importance to interconnects between transistors in integrated circuits. In this work we report the variation of resistivity associated with surface scattering of ex-situ annealed single crystal Ru thin films grown on sapphire substrates by sputter deposition. A set of samples were overcoated with dielectric and subjected to a variety of reducing and oxidizing anneals. The...
Show moreThe resistivity size effect in nanoscale metals is of both scientific and technological interest, the latter due to its importance to interconnects between transistors in integrated circuits. In this work we report the variation of resistivity associated with surface scattering of ex-situ annealed single crystal Ru thin films grown on sapphire substrates by sputter deposition. A set of samples were overcoated with dielectric and subjected to a variety of reducing and oxidizing anneals. The changes in the chemistry and structure of the dielectric interface induced by the anneals, as determined by x-ray reflectivity and x-ray photoelectron spectroscopy measurements, are related to the changes in the specularity of the surface for electron scattering in the context of the Fuchs-Sondheimer semi-classical model of the resistivity size effect.
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Date Issued: 2019
Identifier: CFE0007454, ucf:52727
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007454

Title: Carbon nanotube (CNT) metallic composite with focus on processing and the resultant properties.
Creator: Billah, Md Muktadir, Chen, Quanfang, Bai, Yuanli, An, Linan, Orlovskaya, Nina, University of Central Florida
Abstract / Description: Metal-carbon nanotubes (CNTs) composites are the promising advanced materials that are being developed to take the advantage of the exceptional properties of CNTs. Because of the intrinsically strong in-plane atomic SP2 bonding CNTs offer high young's modulus (1.0(-)1.8 TPa), high tensile strength (30(-)200 GPa) and high elongation at break (10(-)30%). The thermal conductivity of individual single-walled carbon nanotube (SWCNT) and multi-walled carbon nanotube (MWCNT) are about 6000 W/m-K and...
Show moreMetal-carbon nanotubes (CNTs) composites are the promising advanced materials that are being developed to take the advantage of the exceptional properties of CNTs. Because of the intrinsically strong in-plane atomic SP2 bonding CNTs offer high young's modulus (1.0(-)1.8 TPa), high tensile strength (30(-)200 GPa) and high elongation at break (10(-)30%). The thermal conductivity of individual single-walled carbon nanotube (SWCNT) and multi-walled carbon nanotube (MWCNT) are about 6000 W/m-K and 3000 W/m-K, respectively. Therefore it is expected that by incorporation of CNTs in metal matrices multi-functional composites can be used ideally as thermal interface materials, light-weight high-strength structural materials, electric components, optical devices, electromagnetic absorption materials etc. However, so far results are far from satisfied for CNT composites, mainly due to the fact that there are two main key issues remained without good solutions for CNT composites: the poor uniformity in CNT dispersion and the weak interfacial bonding between CNTs and the matrices. In this study, MWCNTs were functionalized and coated with metals like Cu and Ni by electroless deposition methods prior to their application. Metal coatings result in strong interfacial bonding at CNT-metal interfaces and uniform dispersion. During metal coating processes CNTs are physically separated in electrolyte and after coating they get physically retain the separation by the coated metal layer that they are not allowed to aggregate to form bundles. Moreover, after metal coating, the resultant density of Ni-coated MWCNTs is close to that of molten metal matrix. This prevent separation of CNTs due to buoyancy effects and results in uniform dispersion. Metal coating on CNTs surfaces also allows to form strong interfacial bonding with the metal matrices.SnBi alloy has been identified as novel lead-free thermal interface material (TIM) for electronics packaging. However the thermal conductivity and the mechanical strength of pure SnBi alloy are not sufficient to withstand harsh environment imposed by powder electronics. Therefor how to increase the thermal conductivity and the mechanical strength of SnBi solders becomes important. In this study, MWCNTs have been added into SnBi alloy to form SnBi/CNT composite solders by different material processing methods. First, in sandwich method Cu-coated CNTs were added to the 70Sn-30Bi alloy and mixed mechanically. UTS was increased by 47.6% for 3 wt. % Cu/CNTs addition. Second. Ni-coated CNTs were added by sonication assisted melting method in fabricating 70Sn-30Bi solder. For 3 wt. % Ni-coated MWCNTs, equivalent to 0.6 wt. % pure MWCNTs, UTS and YS were increased by 88.8 % and 112.3% respectively. In addition the thermal conductivity was also increased by more than 70%. Ni-coated CNTs were also added to pure Al by powder metallurgy method. For 7 wt. % Ni/CNTs having diameter 30-50 nm, UTS and YS were increased by 92.7% and 101.6% respectively. For CNTs having diameter 8-15 nm, UTS and YS were increased by 108.9% and 128.2% respectively for 7 wt. % addition. All these results are first time obtained that are much greater than published data on CNT/metal composites. Results discussion and mechanism in reinforcement were also presented.
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Date Issued: 2017
Identifier: CFE0006567, ucf:51320
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006567

Title: Arrangement of Google Search Results and Imperial Ideology: Searching for Benghazi, Libya.
Creator: Stewart, Jacob, Pigg, Stacey, Rounsaville, Angela, Walls, Douglas, University of Central Florida
Abstract / Description: This project responds to an ongoing discussion in scholarship that identifies and analyzes the ideological functions of computer interfaces. In 1994, Cynthia Selfe and Richard Selfe claimed that interfaces are maps of cultural information and are therefore ideological (485). For Selfe and Selfe and other scholars, these interfaces carried a colonial ideology that resulted in Western dominance over other cultures. Since this early scholarship, our perspectives on interface have shifted with...
Show moreThis project responds to an ongoing discussion in scholarship that identifies and analyzes the ideological functions of computer interfaces. In 1994, Cynthia Selfe and Richard Selfe claimed that interfaces are maps of cultural information and are therefore ideological (485). For Selfe and Selfe and other scholars, these interfaces carried a colonial ideology that resulted in Western dominance over other cultures. Since this early scholarship, our perspectives on interface have shifted with changing technology; interfaces can no longer be treated as having persistent and predictable characteristics like texts. I argue that interfaces are interactions among dynamic information that is constantly being updated online. One of the most prominent ways users interact with information online is through the use of search engines such as Google. Interfaces like Google assist users in navigating dynamic cultural information. How this information is arranged in a Google search event has a profound impact on what meaning we make surrounding the search term.In this project, I argue that colonial ideologies are upheld in several Google search events for the term (")Benghazi, Libya.(") I claim that networked connection during Google search events leads to the creation and sustainment of a colonial ideology through patterns of arrangement. Finally, I offer a methodology for understanding how ideologies are created when search events occur. This methodology searches for patterns in connected information in order to understand how they create an ideological lens.
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Date Issued: 2014
Identifier: CFE0005267, ucf:50559
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005267

Title: DESIGN FOR AUDITORY DISPLAYS: IDENTIFYING TEMPORAL AND SPATIAL INFORMATION CONVEYANCE PRINCIPLES.
Creator: Ahmad, Ali, Stanney, Kay, University of Central Florida
Abstract / Description: Designing auditory interfaces is a challenge for current human-systems developers. This is largely due to a lack of theoretical guidance for directing how best to use sounds in today's visually-rich graphical user interfaces. This dissertation provided a framework for guiding the design of audio interfaces to enhance human-systems performance. This doctoral research involved reviewing the literature on conveying temporal and spatial information using audio, using this knowledge to build...
Show moreDesigning auditory interfaces is a challenge for current human-systems developers. This is largely due to a lack of theoretical guidance for directing how best to use sounds in today's visually-rich graphical user interfaces. This dissertation provided a framework for guiding the design of audio interfaces to enhance human-systems performance. This doctoral research involved reviewing the literature on conveying temporal and spatial information using audio, using this knowledge to build three theoretical models to aid the design of auditory interfaces, and empirically validating select components of the models. The three models included an audio integration model that outlines an end-to-end process for adding sounds to interactive interfaces, a temporal audio model that provides a framework for guiding the timing for integration of these sounds to meet human performance objectives, and a spatial audio model that provides a framework for adding spatialization cues to interface sounds. Each model is coupled with a set of design guidelines theorized from the literature, thus combined, the developed models put forward a structured process for integrating sounds in interactive interfaces. The developed models were subjected to a three phase validation process that included review by Subject Matter Experts (SMEs) to assess the face validity of the developed models and two empirical studies. For the SME review, which assessed the utility of the developed models and identified opportunities for improvement, a panel of three audio experts was selected to respond to a Strengths, Weaknesses, Opportunities, and Threats (SWOT) validation questionnaire. Based on the SWOT analysis, the main strengths of the models included that they provide a systematic approach to auditory display design and that they integrate a wide variety of knowledge sources in a concise manner. The main weaknesses of the models included the lack of a structured process for amending the models with new principles, some branches were not considered parallel or completely distinct, and lack of guidance on selecting interface sounds. The main opportunity identified by the experts was the ability of the models to provide a seminal body of knowledge that can be used for building and validating auditory display designs. The main threats identified by the experts were that users may not know where to start and end with each model, the models may not provide comprehensive coverage of all uses of auditory displays, and the models may act as a restrictive influence on designers or they may be used inappropriately. Based on the SWOT analysis results, several changes were made to the models prior to the empirical studies. Two empirical evaluation studies were conducted to test the theorized design principles derived from the revised models. The first study focused on assessing the utility of audio cues to train a temporal pacing task and the second study combined both temporal (i.e., pace) and spatial audio information, with a focus on examining integration issues. In the pace study, there were four different auditory conditions used for training pace: 1) a metronome, 2) non-spatial auditory earcons, 3) a spatialized auditory earcon, and 4) no audio cues for pace training. Sixty-eight people participated in the study. A pre- post between subjects experimental design was used, with eight training trials. The measure used for assessing pace performance was the average deviation from a predetermined desired pace. The results demonstrated that a metronome was not effective in training participants to maintain a desired pace, while, spatial and non-spatial earcons were effective strategies for pace training. Moreover, an examination of post-training performance as compared to pre-training suggested some transfer of learning. Design guidelines were extracted for integrating auditory cues for pace training tasks in virtual environments. In the second empirical study, combined temporal (pacing) and spatial (location of entities within the environment) information were presented. There were three different spatialization conditions used: 1) high fidelity using subjective selection of a "best-fit" head related transfer function, 2) low fidelity using a generalized head-related transfer function, and 3) no spatialization. A pre- post between subjects experimental design was used, with eight training trials. The performance measures were average deviation from desired pace and time and accuracy to complete the task. The results of the second study demonstrated that temporal, non-spatial auditory cues were effective in influencing pace while other cues were present. On the other hand, spatialized auditory cues did not result in significantly faster task completion. Based on these results, a set of design guidelines was proposed that can be used to direct the integration of spatial and temporal auditory cues for supporting training tasks in virtual environments. Taken together, the developed models and the associated guidelines provided a theoretical foundation from which to direct user-centered design of auditory interfaces.
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Date Issued: 2007
Identifier: CFE0001719, ucf:47317
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0001719

Title: PERFORMANCE OF INTERFACE ELEMENTS IN THE FINITE ELEMENT METHOD.
Creator: Rabadi, Kairas, Nicholson, David, University of Central Florida
Abstract / Description: The objective of this research is to assess the performance of interface elements in the finite element method. Interface elements are implemented in the finite element codes such as MSC.NASTRAN, which is used in this study. Interface elements in MSC.NASTRAN provide a tool to transition between a shell-meshed region to another shell-meshed region as well as from a shell-meshed region to a solid-meshed region. Often, in practice shell elements are layered on shell elements or on solid elements...
Show moreThe objective of this research is to assess the performance of interface elements in the finite element method. Interface elements are implemented in the finite element codes such as MSC.NASTRAN, which is used in this study. Interface elements in MSC.NASTRAN provide a tool to transition between a shell-meshed region to another shell-meshed region as well as from a shell-meshed region to a solid-meshed region. Often, in practice shell elements are layered on shell elements or on solid elements without the use of interface elements. This is potentially inaccurate arising in mismatched degrees of freedom. In the case of a shell-to-shell interface, we consider the case in which the two regions have mismatched nodes along the boundary. Interface elements are used to connect these mismatched nodes. The interface elements are especially useful in global/local analysis, where a region with a dense mesh interfaces to a region with a less dense mesh. Interface elements are used to help avoid using special transition elements between two meshed regions. This is desirable since the transition elements can be severely distorted and cause poor results. Accurate results are obtained in shell-shell and shell-solid combinations. The most interesting result is that not using interface elements can lead to severe inaccuracies. This difficulty is illustrated by computing the stress concentration of a sharp elliptical hole.
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Date Issued: 2004
Identifier: CFE0000291, ucf:46209
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0000291

Title: BURSTING THE FILTER BUBBLE: INFORMATION LITERACY AND QUESTIONS OF VALUATION, NAVIGATION, AND CONTROL IN A DIGITAL LANDSCAPE.
Creator: Hassan, Komysha, Guenzel, Steffen, University of Central Florida
Abstract / Description: The evolution of social media platforms and other public forums in the digital realm has created an explosion of user-generated content and data as a component of the already content-saturated digital landscape. The distributed, horizontal nature of the internet as a platform makes it difficult to ascertain value and differentiate between texts of varying validity, bias, and purpose. In addition, the internet is not an inanimate interface. As Pariser (2011) argues, content aggregators, such...
Show moreThe evolution of social media platforms and other public forums in the digital realm has created an explosion of user-generated content and data as a component of the already content-saturated digital landscape. The distributed, horizontal nature of the internet as a platform makes it difficult to ascertain value and differentiate between texts of varying validity, bias, and purpose. In addition, the internet is not an inanimate interface. As Pariser (2011) argues, content aggregators, such as Google, actively filter, personalize, and therefore limit each individual's access to information, in both range and type. This has created a crisis of information valuation and control. Importantly, conventional curriculum does not furnish students with the information literacy tools necessary for them to navigate the digital landscape effectively. Information miners and developers, including news organizations, are falling victim to this fallacy as well. Lankshear and Knobel (2011) posit that empowering navigation and control in the digital landscape requires a new mindset. This research offers a context-driven approach that acknowledges this new mindset, promoting "rhetorical consciousness" (Murphy et al., 2003) within the network and providing a framework to recognize, challenge, and co-create gatekeeping roles and mechanism as they increasingly shift to the individual.
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Date Issued: 2018
Identifier: CFH2000326, ucf:45733
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFH2000326

Title: A framework for prioritizing opportunities of improvement in the context of business excellence model in healthcare organization.
Creator: Aldarmaki, Alia, Elshennawy, Ahmad, Lee, Gene, Rabelo, Luis, Darwish, Mohammed, University of Central Florida
Abstract / Description: In today's world, the healthcare sector is facing challenges to improve the efficiency and effectiveness of its operations. More and more improvement projects are being adopted to enhance healthcare services, making it more patient-centric, and enabling better cost control. Healthcare organizations strive to identify and carry out such improvement initiatives to sustain their businesses and gain competitive advantage. Seeking to reach a higher operational level of excellence, healthcare...
Show moreIn today's world, the healthcare sector is facing challenges to improve the efficiency and effectiveness of its operations. More and more improvement projects are being adopted to enhance healthcare services, making it more patient-centric, and enabling better cost control. Healthcare organizations strive to identify and carry out such improvement initiatives to sustain their businesses and gain competitive advantage. Seeking to reach a higher operational level of excellence, healthcare organizations utilize business excellence criteria to conduct assessment and identify organizational strengths and weaknesses. However, while such assessments routinely identify numerous areas for potential improvement, it is not feasible to conduct all improvement projects simultaneously due to limitations in time, capital, and personnel, as well as conflict with other organization's projects or strategic objectives. An effective prioritization and selection approach is valuable in that it can assist the organization to optimize its available resources and outcomes. This study attempts to enable such an approach by developing a framework to prioritize improvement opportunities in healthcare in the context of the business excellence model through the integration of the Fuzzy Delphi Method and Fuzzy Interface System. To carry out the evaluation process, the framework consists of two phases. The first phase utilizes Fuzzy Delphi Method to identify the most significant factors that should be considered in healthcare for electing the improvement projects. The FDM is employed to handle the subjectivity of human assessment. The research identifies potential factors for evaluating projects, then utilizes FDM to capture expertise knowledge. The first round in FDM is intended to validate the identified list of factors from experts; which includes collecting additional factors from experts that the literature might have overlooked. When an acceptable level of consensus has been reached, a second round is conducted to obtain experts' and other related stakeholders' opinions on the appropriate weight of each factor's importance. Finally, FDM analyses eliminate or retain the criteria to produce a final list of critical factors to select improvement projects. The second phase in the framework attempts to prioritize improvement initiatives using the Hierarchical Fuzzy Interface System. The Fuzzy Interface System combines the experts' ratings for each improvement opportunity with respect to the factors deemed critical to compute the priority index. In the process of calculating the priority index, the framework allows the estimation of other intermediate indices including: social, financial impact, strategical, operational feasibility, and managerial indices. These indices bring an insight into the improvement opportunities with respect to each framework's dimensions. The framework allows for a reduction of the bias in the assessment by developing a knowledge based on the perspectives of multiple experts.
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Date Issued: 2018
Identifier: CFE0007304, ucf:52158
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007304

Title: Getting the Upper Hand: Natural Gesture Interfaces Improve Instructional Efficiency on a Conceptual Computer Lesson.
Creator: Bailey, Shannon, Sims, Valerie, Jentsch, Florian, Bowers, Clint, Johnson, Cheryl, University of Central Florida
Abstract / Description: As gesture-based interactions with computer interfaces become more technologically feasible for educational and training systems, it is important to consider what interactions are best for the learner. Computer interactions should not interfere with learning nor increase the mental effort of completing the lesson. The purpose of the current set of studies was to determine whether natural gesture-based interactions, or instruction of those gestures, help the learner in a computer lesson by...
Show moreAs gesture-based interactions with computer interfaces become more technologically feasible for educational and training systems, it is important to consider what interactions are best for the learner. Computer interactions should not interfere with learning nor increase the mental effort of completing the lesson. The purpose of the current set of studies was to determine whether natural gesture-based interactions, or instruction of those gestures, help the learner in a computer lesson by increasing learning and reducing mental effort. First, two studies were conducted to determine what gestures were considered natural by participants. Then, those gestures were implemented in an experiment to compare type of gesture and type of gesture instruction on learning conceptual information from a computer lesson. The goal of these studies was to determine the instructional efficiency (-) that is, the extent of learning taking into account the amount of mental effort (-) of implementing gesture-based interactions in a conceptual computer lesson. To test whether the type of gesture interaction affects conceptual learning in a computer lesson, the gesture-based interactions were either naturally- or arbitrarily-mapped to the learning material on the fundamentals of optics. The optics lesson presented conceptual information about reflection and refraction, and participants used the gesture-based interactions during the lesson to manipulate on-screen lenses and mirrors in a beam of light. The beam of light refracted/reflected at the angle corresponding with type of lens/mirror. The natural gesture-based interactions were those that mimicked the physical movement used to manipulate the lenses and mirrors in the optics lesson, while the arbitrary gestures were those that did not match the movement of the lens or mirror being manipulated. The natural gestures implemented in the computer lesson were determined from Study 1, in which participants performed gestures they considered natural for a set of actions, and rated in Study 2 as most closely resembling the physical interaction they represent. The arbitrary gestures were rated by participants as most arbitrary for each computer action in Study 2. To test whether the effect of novel gesture-based interactions depends on how they are taught, the way the gestures were instructed was varied in the main experiment by using either video- or text-based tutorials. Results of the experiment support that natural gesture-based interactions were better for learning than arbitrary gestures, and instruction of the gestures largely did not affect learning and amount of mental effort felt during the task. To further investigate the factors affecting instructional efficiency in using gesture-based interactions for a computer lesson, individual differences of the learner were taken into account. Results indicated that the instructional efficiency of the gestures and their instruction depended on an individual's spatial ability, such that arbitrary gesture interactions taught with a text-based tutorial were particularly inefficient for those with lower spatial ability. These findings are explained in the context of Embodied Cognition and Cognitive Load Theory, and guidelines are provided for instructional design of computer lessons using natural user interfaces. The theoretical frameworks of Embodied Cognition and Cognitive Load Theory were used to explain why gesture-based interactions and their instructions impacted the instructional efficiency of these factors in a computer lesson. Gesture-based interactions that are natural (i.e., mimic the physical interaction by corresponding to the learning material) were more instructionally efficient than arbitrary gestures because natural gestures may help schema development of conceptual information through physical enactment of the learning material. Furthermore, natural gestures resulted in lower cognitive load than arbitrary gestures, because arbitrary gestures that do not match the learning material may increase the working memory processing not associated with the learning material during the lesson. Additionally, the way in which the gesture-based interactions were taught was varied by either instructing the gestures with video- or text-based tutorials, and it was hypothesized that video-based tutorials would be a better way to instruct gesture-based interactions because the videos may help the learner to visualize the interactions and create a more easily recalled sensorimotor representation for the gestures; however, this hypothesis was not supported and there was not strong evidence that video-based tutorials were more instructionally efficient than text-based instructions. The results of the current set of studies can be applied to educational and training systems that incorporate a gesture-based interface. The finding that more natural gestures are better for learning efficiency, cognitive load, and a variety of usability factors should encourage instructional designers and researchers to keep the user in mind when developing gesture-based interactions.
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Date Issued: 2017
Identifier: CFE0007278, ucf:52192
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007278

Title: Motor imagery classification using sparse representation of EEG signals.
Creator: Saidi, Pouria, Atia, George, Vosoughi, Azadeh, Berman, Steven, University of Central Florida
Abstract / Description: The human brain is unquestionably the most complex organ of the body as it controls and processes its movement and senses. A healthy brain is able to generate responses to the signals it receives, and transmit messages to the body. Some neural disorders can impair the communication between the brain and the body preventing the transmission of these messages. Brain Computer Interfaces (BCIs) are devices that hold immense potential to assist patients with such disorders by analyzing brain...
Show moreThe human brain is unquestionably the most complex organ of the body as it controls and processes its movement and senses. A healthy brain is able to generate responses to the signals it receives, and transmit messages to the body. Some neural disorders can impair the communication between the brain and the body preventing the transmission of these messages. Brain Computer Interfaces (BCIs) are devices that hold immense potential to assist patients with such disorders by analyzing brain signals, translating and classifying various brain responses, and relaying them to external devices and potentially back to the body. Classifying motor imagery brain signals where the signals are obtained based on imagined movement of the limbs is a major, yet very challenging, step in developing Brain Computer Interfaces (BCIs). Of primary importance is to use less data and computationally efficient algorithms to support real-time BCI. To this end, in this thesis we explore and develop algorithms that exploit the sparse characteristics of EEGs to classify these signals. Different feature vectors are extracted from EEG trials recorded by electrodes placed on the scalp.In this thesis, features from a small spatial region are approximated by a sparse linear combination of few atoms from a multi-class dictionary constructed from the features of the EEG training signals for each class. This is used to classify the signals based on the pattern of their sparse representation using a minimum-residual decision rule.We first attempt to use all the available electrodes to verify the effectiveness of the proposed methods. To support real time BCI, the electrodes are reduced to those near the sensorimotor cortex which are believed to be crucial for motor preparation and imagination.In a second approach, we try to incorporate the effect of spatial correlation across the neighboring electrodes near the sensorimotor cortex. To this end, instead of considering one feature vector at a time, we use a collection of feature vectors simultaneously to find the joint sparse representation of these vectors. Although we were not able to see much improvement with respect to the first approach, we envision that such improvements could be achieved using more refined models that can be subject of future works. The performance of the proposed approaches is evaluated using different features, including wavelet coefficients, energy of the signals in different frequency sub-bands, and also entropy of the signals. The results obtained from real data demonstrate that the combination of energy and entropy features enable efficient classification of motor imagery EEG trials related to hand and foot movements. This underscores the relevance of the energies and their distribution in different frequency sub-bands for classifying movement-specific EEG patterns in agreement with the existence of different levels within the alpha band. The proposed approach is also shown to outperform the state-of-the-art algorithm that uses feature vectors obtained from energies of multiple spatial projections.
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Date Issued: 2015
Identifier: CFE0005882, ucf:50884
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005882

Title: Local transient characterization of thermofluid heat transfer coefficient at solid-liquid nano-interfaces.
Creator: Mehrvand, Mehrdad, Putnam, Shawn, Peles, Yoav, Orlovskaya, Nina, Abdolvand, Reza, University of Central Florida
Abstract / Description: The demands for increasingly smaller, more capable, and higher power density technologies in microelectronics, energy, or aerospace systems have heightened the need for new methods to manage and characterize extreme heat fluxes (EHF). Microscale liquid cooling techniques are viewed as a promising solution for removing heat from high heat flux (HHF) systems. However, there have been challenges in physical understanding and predicting local thermal transport at the interface of micro and...
Show moreThe demands for increasingly smaller, more capable, and higher power density technologies in microelectronics, energy, or aerospace systems have heightened the need for new methods to manage and characterize extreme heat fluxes (EHF). Microscale liquid cooling techniques are viewed as a promising solution for removing heat from high heat flux (HHF) systems. However, there have been challenges in physical understanding and predicting local thermal transport at the interface of micro and nanoscale structures/devices due to ballistic effects and complex coupling of mass, momentum, and energy transport at the solid-liquid-vapor interfaces over multiple time and length scales. Moreover, it's challenging to experimentally validate new HHF models due to lack of high resolution techniques and measurements.This dissertation presents the use of a high spatiotemporal and temperature resolution measurement technique, called Time-domain Thermoreflectance (TDTR). TDTR is used to characterize the local heat transfer coefficient (HTC) of a water-cooled rectangular microchannel in a combined hot-spot heating and sub-cooled channel-flow configuration. Studies focused on room temperature, syringe-pumped single-and two-phase water flow in a ?480 ?m hydraulic diameter microchannel, where the TDTR pump heating laser induces local heat fluxes of ?0.5-2.5 KW/cm2 in the center of the microchannel on the surface of a 60-80 nm metal or alloy thin film transducer with hot-spot diameters of ?7-10 ?m. In the single-phase part, a differential measurement approach is developed by applying anisotropic version of the TDTR to predict local HTC using the measured voltage ratio parameter, and then fitting data to a thermal model for layered materials and interfaces. It's shown that thermal effusivity distribution of the water coolant over the hot-spot is correlated to the local HTC, where both the stagnant fluid (i.e., conduction and natural convection) and flowing fluid (i.e., forced convection) contributions are decoupled from each other. Measurements of the local enhancement in the HTC over the hot-spot are in good agreement with established Nusselt number correlations. For example, flow cooling results using a Ti metal wall support a maximum HTC enhancement via forced convection of ?1060(&)#177;190 kW/m2?K, where the well-established Nusselt number correlations predict ?900(&)#177;150 kW/m2?K.In the two-phase part, pump-probe beams are first used to construct the local pool and flow boiling curves at different heat fluxes and hot spot temperatures as a function of HTC enhancement. At a same heat flux level, it's observed that fluid flow enhances HTC by shifting heat transfer mechanism (or flow regime) from film boiling to nucleate boiling. Based on observations, it's hypothesized that beyond an EHF flow may reduce the bubble size and increase evaporation at the liquid-vapor interface on three-phase contact line, but it's unable to rewet and cool down the dry spot at the center due to the EHF. In the last part of two-phase experiments, transient measurements are performed at a specific heat flux to obtain thermal temporal fluctuations and HTC of a single bubble boiling and nucleation during its ebullition cycle. The total laser power is chosen to be between the minimum required to start subcooled nucleation and CHF of the pool boiling. This range is critical since within 10% change in heating flux, flow can have dramatic effect on HTC. Whenever the flow gets closer to the dry spot and passes through it (receding or advancing) HTC increases suddenly. This means that for very hot surfaces (or regions of wall dry-out), continuous and small bubbles on the order of thermal diffusion time and dry spot length scales respectively could be a reliable high heat flux cooling solution. This could be achieved by controlling the bubble size and frequency through geometry, surface structure and properties, and fluid's thermos-fluid properties.
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Date Issued: 2017
Identifier: CFE0006765, ucf:51832
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006765

Title: Intelligent Selection Techniques For Virtual Environments.
Creator: Cashion, Jeffrey, Laviola II, Joseph, Bassiouni, Mostafa, Hughes, Charles, Bowman, Doug, University of Central Florida
Abstract / Description: Selection in 3D games and simulations is a well-studied problem. Many techniques have been created to address many of the typical scenarios a user could experience. For any single scenario with consistent conditions, there is likely a technique which is well suited. If there isn't, then there is an opportunity for one to be created to best suit the expected conditions of that new scenario. It is critical that the user be given an appropriate technique to interact with their environment....
Show moreSelection in 3D games and simulations is a well-studied problem. Many techniques have been created to address many of the typical scenarios a user could experience. For any single scenario with consistent conditions, there is likely a technique which is well suited. If there isn't, then there is an opportunity for one to be created to best suit the expected conditions of that new scenario. It is critical that the user be given an appropriate technique to interact with their environment. Without it, the entire experience is at risk of becoming burdensome and not enjoyable.With all of the different possible scenarios, it can become problematic when two or more are part of the same program. If they are put closely together, or even intertwined, then the developer is often forced to pick a single technique that works so-so in both, but is likely not optimal for either, or maybe optimal in just one of them. In this case, the user is left to perform selections with a technique that is lacking in one way or another, which can increase errors and frustration.In our research, we have outlined different selection scenarios, all of which were classified by their level of object density (number of objects in scene) and object velocity. We then performed an initial study on how it impacts performance of various selection techniques, including a new selection technique that we developed just for this test, called Expand. Our results showed, among other things, that a standard Raycast technique works well in slow moving and sparse environments, while revealing that our new Expand technique works well in denser environments.With the results from our first study, we sought to develop something that would bridge the gap in performance between those selection techniques tested. Our idea was a framework that could harvest several different selection techniques and determine which was the most optimal at any time. Each selection technique would report how effective it was, given the provided scenario conditions. The framework was responsible for activating the appropriate selection technique when the user made a selection attempt. With this framework in hand, we performed two additional user studies to determine how effective it could be in actual use, and to identify its strengths and weaknesses. Each study compared several selection techniques individually against the framework which utilized them collectively, picking the most suitable. Again, the same scenarios from our first study were reused. From these studies, we gained a deeper understanding of the many challenges associated with automatic selection technique determination. The results from these two studies showed that transitioning between techniques was potentially viable, but rife with design challenges that made its optimization quite difficult.In an effort to sidestep some of the issues surrounding the switching of discrete techniques, we sought to attack the problem from the other direction, and make a single technique act similarly to two techniques, adjusting dynamically to conditions. We performed a user study to analyze the performance of such a technique, with promising results. While the qualitative differences were small, the user feedback did indicate that users preferred this technique over the others, which were static in nature.Finally, we sought to gain a deeper understanding of existing selection techniques that were dynamic in nature, and study how they were designed, and how they could be improved. We scrutinized the attributes of each technique that were already being adjusted dynamically or that could be adjusted and innovated new ways in which the technique could be improved upon. Within this analysis, we also gave thought to how each technique could be best integrated into the Auto-Select framework we proposed earlier. This overall analysis of the latest selection techniques left us with an array of new variants that warrant being created and tested against their existing versions.Our overall research goal was to perform an analysis of selection techniques that intelligently adapt to their environment. We believe that we achieved this by performing several iterative development cycles, including user studies and ultimately leading to innovation in the field of selection. We conclude our research with yet more questions left to be answered. We intend to pursue further research regarding some of these questions, as time permits.
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Date Issued: 2014
Identifier: CFE0005469, ucf:50381
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005469

Title: SketChart: A Pen-Based Tool for Chart Generation and Interaction.
Creator: Vargas Gonzalez, Andres, Laviola II, Joseph, Foroosh, Hassan, Hua, Kien, University of Central Florida
Abstract / Description: It has been shown that representing data with the right visualization increases the understanding of qualitative and quantitative information encoded in documents. However, current tools for generating such visualizations involve the use of traditional WIMP techniques, which perhaps makes free interaction and direct manipulation of the content harder. In this thesis, we present a pen-based prototype for data visualization using 10 different types of bar based charts. The prototype lets users...
Show moreIt has been shown that representing data with the right visualization increases the understanding of qualitative and quantitative information encoded in documents. However, current tools for generating such visualizations involve the use of traditional WIMP techniques, which perhaps makes free interaction and direct manipulation of the content harder. In this thesis, we present a pen-based prototype for data visualization using 10 different types of bar based charts. The prototype lets users sketch a chart and interact with the information once the drawing is identified. The prototype's user interface consists of an area to sketch and touch based elements that will be displayed depending on the context and nature of the outline. Brainstorming and live presentations can benefit from the prototype due to the ability to visualize and manipulate data in real time. We also perform a short, informal user study to measure effectiveness of the tool while recognizing sketches and users acceptance while interacting with the system. Results show SketChart strengths and weaknesses and areas for improvement.
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Date Issued: 2014
Identifier: CFE0005434, ucf:50405
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005434

Title: EFFECT OF OPERATOR CONTROL CONFIGURATION ON UNMANNED AERIAL SYSTEM TRAINABILITY.
Creator: Neumann, John, Kincaid, Peter, University of Central Florida
Abstract / Description: Unmanned aerial systems (UAS) carry no pilot on board, yet they still require live operators to handle critical functions such as mission planning and execution. Humans also interpret the sensor information provided by these platforms. This applies to all classes of unmanned aerial vehicles (UAV's), including the smaller portable systems used for gathering real-time reconnaissance during military operations in urban terrain. The need to quickly and reliably train soldiers to control small...
Show moreUnmanned aerial systems (UAS) carry no pilot on board, yet they still require live operators to handle critical functions such as mission planning and execution. Humans also interpret the sensor information provided by these platforms. This applies to all classes of unmanned aerial vehicles (UAV's), including the smaller portable systems used for gathering real-time reconnaissance during military operations in urban terrain. The need to quickly and reliably train soldiers to control small UAS operations demands that the human-system interface be intuitive and easy to master. In this study, participants completed a series of tests of spatial ability and were then trained (in simulation) to teleoperate a micro-unmanned aerial vehicle equipped with forward and downward fixed cameras. Three aspects of the human-system interface were manipulated to assess the effects on manual control mastery and target detection. One factor was the input device. Participants used either a mouse or a specially programmed game controller (similar to that used with the Sony™ Playstation 2 video game console). A second factor was the nature of the flight control displays as either continuous or discrete (analog v. digital). The third factor involved the presentation of sensor imagery. The display could either provide streaming video from one camera at a time, or present the imagery from both cameras simultaneously in separate windows. The primary dependent variables included: 1) time to complete assigned missions, 2) number of collisions, 3) number of targets detected, and 4) operator workload. In general, operator performance was better with the game controller than with the mouse, but significant improvement in time to complete occurred over repeated trials regardless of the device used. Time to complete missions was significantly faster with the game controller, and operators also detected more targets without any significant differences in workload compared to mouse users. Workload on repeated trials decreased with practice, and spatial ability was a significant covariate of workload. Lower spatial ability associated with higher workload scores. In addition, demographic data including computer usage and video gaming experience were collected and analyzed, and correlated with performance. Higher video gaming experience was also associated with lower workload.
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Date Issued: 2006
Identifier: CFE0001496, ucf:47080
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0001496

Title: DEVELOPING A SPATIAL INTERFACE FOR INFORMATION VISUALIZATION AND MANAGEMENT IN A CRISIS RESPONSE SCENARIO.
Creator: Costello, Anthony, Tang, Arthur, University of Central Florida
Abstract / Description: The focus of this study was to investigate how a spatial interface can be effectively utilized to support information presentation and information integration via human-centric data visualization, leading to decreased cognitive load, more accurate situation awareness, and subsequently, improved task performance. In high tempo, information intensive environments like those managed by an emergency operations center (EOC), information organization tools are essential. Though users can be trained...
Show moreThe focus of this study was to investigate how a spatial interface can be effectively utilized to support information presentation and information integration via human-centric data visualization, leading to decreased cognitive load, more accurate situation awareness, and subsequently, improved task performance. In high tempo, information intensive environments like those managed by an emergency operations center (EOC), information organization tools are essential. Though users can be trained to use conventional email software applications efficiently, the constraints of the information management paradigms inherent to conventional systems may limit a user's ability to gather context and create an accurate picture of the situation. It is possible that new data visualization techniques and information management paradigms may improve a user's performance far beyond these limits. To address these issues, theories regarding information management, cognitive workload and data visualization paradigms were explored and applied to create a software prototype spatial interface. This study focused on how an individual member of an EOC would need to collect and organize incoming incident reports (e.g., emails) for the purpose of quick analysis and integration. The operator then used this information to build a picture of the event or events taking place in their sphere of influence. Performance metrics were applied to determine whether or not an individual could perform faster and more accurately with the Incident Report Visual Organizer (IRVO) prototype software interface as opposed to a conventional interface (Microsoft Outlook). The findings from this exploratory evaluation are discussed, as well as the potential implications of utilizing spatial interfaces to manage information in dynamic environments.
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Date Issued: 2007
Identifier: CFE0001770, ucf:47264
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0001770

Title: MECHANISMS OF LIFETIME IMPROVEMENT IN THERMAL BARRIER COATINGS WITH HF AND/OR Y MODIFICATION OF CMSX-4 SUPERALLOY SUBSTRATES.
Creator: Liu, Jing, Sohn, Yong ho, University of Central Florida
Abstract / Description: In modern turbine engines for propulsion and energy generation, thermal barrier coating (TBCs) protect hot-section blades and vanes, and play a critical role in enhancing reliability, durability and operation efficiency. In this study, thermal cyclic lifetime and microstructural degradation of electron beam physical vapor deposited (EB-PVD) Yttria Stabilized Zirconia (YSZ) with (Ni,Pt)Al bond coat and Hf- and/or Y- modified CMSX-4 superalloy substrates were examined. Thermal cyclic lifetime...
Show moreIn modern turbine engines for propulsion and energy generation, thermal barrier coating (TBCs) protect hot-section blades and vanes, and play a critical role in enhancing reliability, durability and operation efficiency. In this study, thermal cyclic lifetime and microstructural degradation of electron beam physical vapor deposited (EB-PVD) Yttria Stabilized Zirconia (YSZ) with (Ni,Pt)Al bond coat and Hf- and/or Y- modified CMSX-4 superalloy substrates were examined. Thermal cyclic lifetime of TBCs was measured using a furnace thermal cycle test that consisted of 10-minute heat-up, 50-minute dwell at 1135C, and 10-minute forced-air-quench. TBC lifetime was observed to improve from 600 cycles to over 3200 cycles with appropriated Hf- and/or Y alloying of CMSX-4 superalloys. This significant improvement in TBC lifetime is the highest reported lifetime in literature with similar testing parameters. Beneficial role of reactive element (RE) on the durability of TBCS were systematically investigated in this study. Photostimulated luminescence spectroscopy (PL) was employed to non-destructively measure the residual stress within the TGO scale as a function of thermal cycling. Extensive microstructural analysis with emphasis on the YSZ/TGO interface, TGO scale, TGO/bond coat interface was carried out by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and scanning electron microscopy (STEM) as a funcion of thermal cycling including after the spallation failure. Focused ion beam in-situ lift-out (FIB-INLO) technique was employed to prepare site-specific TEM specimens. X-ray diffraction (XRD) and secondary ion mass spectroscopy (SIMS) were also employed for phase identification and interfacial chemical analysis. While undulation of TGO/bond coat interface (e.g., rumpling and ratcheting) was observed to be the main mechanism of degradation for the TBCs on baseline CMSX-4, the same interface remained relatively flat (e.g., suppressed rumpling and ratcheting) for durable TBCs on Hf- and/or Y-modified CMSX-4. The fracture paths changed from the YSZ/TGO interface to the TGO/bond coat interface when rumpling was suppressed. The geometrical incompatibility between the undulated TGO and EB-PVD YSZ lead to the failure at the YSZ/TGO interface for TBCs with baseline CMSX-4. The magnitude of copressive residual stress within the TGO scale measured by PL gradually decreased as a function of thermal cycling for TBCs with baseline CMSX-4 superalloy substrates. This gradual decrease corrsponds well to the undulation of the TGO scale that may lead to relaxation of the compressive residual stress within the TGO scale. For TBCs with Hf- and/or Y-modified CMSX-4 superalloy substrates, the magnitude of compressive residual stress within the TGO scale remained relatively constant throughout the thermal cycling, although PL corresponding to the stress-relief caused by localized cracks at the TGO/bond coat interface and within the TGO scale was observed frequently starting 50% of lifetime. A slightly smaller parabolic growth constant and grain size of the TGO scale was observed for TBCs with Hf- and/or Y- modified CMSX-4. Small monoclinic HfO2 precipitates were observed to decorate grain boundaries and the triple pointes within the alpha-Al2O3 scale for TBCs with Hf- and/or Y-modified CMSX-4 substrates. Segregation of Hf/Hf4+ at the TGO/bond coat interfaces was also observed for TBCs with Hf- and/or Y-modified CMSX-4 superalloys substrates. Adherent and pore-free YSZ/TGO interface was observed for TBCs with Hf- and/or Y-modified CMSX-4, while a significant amount of decohesion at the YSZ/TGO interface was observed for TBCs with baseline CMSX-4. The beta-NiAl(B2) phase in the (Ni,Pt)Al bond coat was observed to partially transform into gama prime-Ni3Al (L12) phase due to depletion of Al in the bond coat during oxidation. More importantly, the remaining beta-NiAl phase transformed into L10 martensitic phase upon cooling even though there was no significant difference in these phase transformations for all TBCs. Results from these microstructural observations are documented to elucidate mechanisms that suppress the rumpling of the TGO/bond coat interface, which is responsible for superior performance of EB-PVD TBCs with (Ni,Pt)Al bond coat and Hf- and/or Y-modified CMXS-4 superalloy.
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Date Issued: 2007
Identifier: CFE0001872, ucf:47382
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0001872

Title: ADAPTIVE INTELLIGENT USER INTERFACES WITH EMOTION RECOGNITION.
Creator: NASOZ, FATMA, Christine Lisetti, Dr L., University of Central Florida
Abstract / Description: The focus of this dissertation is on creating Adaptive Intelligent User Interfaces to facilitate enhanced natural communication during the Human-Computer Interaction by recognizing users' affective states (i.e., emotions experienced by the users) and responding to those emotions by adapting to the current situation via an affective user model created for each user. Controlled experiments were designed and conducted in a laboratory environment and in a Virtual Reality environment to collect...
Show moreThe focus of this dissertation is on creating Adaptive Intelligent User Interfaces to facilitate enhanced natural communication during the Human-Computer Interaction by recognizing users' affective states (i.e., emotions experienced by the users) and responding to those emotions by adapting to the current situation via an affective user model created for each user. Controlled experiments were designed and conducted in a laboratory environment and in a Virtual Reality environment to collect physiological data signals from participants experiencing specific emotions. Algorithms (k-Nearest Neighbor [KNN], Discriminant Function Analysis [DFA], Marquardt-Backpropagation [MBP], and Resilient Backpropagation [RBP]) were implemented to analyze the collected data signals and to find unique physiological patterns of emotions. Emotion Elicitation with Movie Clips Experiment was conducted to elicit Sadness, Anger, Surprise, Fear, Frustration, and Amusement from participants. Overall, the three algorithms: KNN, DFA, and MBP, could recognize emotions with 72.3%, 75.0%, and 84.1% accuracy, respectively. Driving Simulator experiment was conducted to elicit driving-related emotions and states (panic/fear, frustration/anger, and boredom/sleepiness). The KNN, MBP and RBP Algorithms were used to classify the physiological signals by corresponding emotions. Overall, KNN could classify these three emotions with 66.3%, MBP could classify them with 76.7% and RBP could classify them with 91.9% accuracy. Adaptation of the interface was designed to provide multi-modal feedback to the users about their current affective state and to respond to users' negative emotional states in order to decrease the possible negative impacts of those emotions. Bayesian Belief Networks formalization was employed to develop the User Model to enable the intelligent system to appropriately adapt to the current context and situation by considering user-dependent factors, such as: personality traits and preferences.
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Date Issued: 2004
Identifier: CFE0000126, ucf:46201
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0000126

Title: PERFORMANCE SUPPORT AND USABILITY:AN EXPERIMENTAL STUDY OFELECTRONIC PERFORMANCE SUPPORT INTERFACES.
Creator: Rawls, Charles, Hirumi, Atsusi, University of Central Florida
Abstract / Description: This study evaluated the usability of two types of performance-support interfaces that were designed using informational and experiential approaches. The experiment sought to determine whether there is a relationship between usability and the informational and experiential approaches. The general population under study was undergraduate education major students from the University of Central Florida. From the general population of three educational technology instructor-led classes, 83...
Show moreThis study evaluated the usability of two types of performance-support interfaces that were designed using informational and experiential approaches. The experiment sought to determine whether there is a relationship between usability and the informational and experiential approaches. The general population under study was undergraduate education major students from the University of Central Florida. From the general population of three educational technology instructor-led classes, 83 students were solicited to participate in the study by completing a class activity. From the general population, a total of 63 students participated in the study. By participating in the study, the students completed a task and a questionnaire. Students were predominantly English-speaking Caucasian female education majors between the ages of 19 and 20; most of them were sophomores or juniors working part time. They possessed moderately low to high computer skills and most considered themselves to have intermediate or expert Internet skills. An experimental posttest-only comparison group research design was used to test the hypotheses posited for this study. The participants were randomly assigned to either the informational interface group (X1) or the experiential interface group (X2), and the experiment was conducted electronically via a Web-based Content Management System (CMS). The observed data consisted of five outcome measures: efficiency, errors, intuitiveness, satisfaction, and student performance. Two instruments--a checklist and an online usability questionnaire--were used to measure the five dependent variables: efficiency, intuitiveness, errors, satisfaction, and student performance. The CMS was used as the vehicle to distribute and randomize the two interfaces, obtain informed consent, distribute the instructions, distribute the online questionnaire, and collect data. First, a checklist was used to assess the students' performance completing their task, which was a copyright issue request letter. The checklist was designed as a performance criterion tool for the researcher, instructor, and participants to use. The researcher and instructor constructed the checklist to grade copyright request letters and determine students' performance. The participants had the opportunity to use the checklist as a performance criterion to create the task document (copyright request letter). The checklist consisted of ten basic yet critical sections of a successful copyright request letter. Second, an online usability questionnaire was constructed based on the Purdue Usability Testing Questionnaire (PUTQ) questions to measure interface efficiency, intuitiveness, errors, and satisfaction. While these test items have been deemed important for testing the usability of a particular system, for purposes of this study, test items were modified, deleted, and added to ensure content validity. The new survey, University of Central Florida Usability Questionnaire (UCFUQ), consisting of 20 items, was implemented in a pilot study to ensure reliability and content validity. Changes to the PUTQ were modified to fulfill a blueprint. A pilot study of the instrument yielded a reliability coefficient of .9450, and the final online usability instrument yielded a reliability coefficient of .9321. This study tested two approaches to user interface design for the Electronic Performance Support (EPS) using two HTML interface templates and the information from an existing training module. There were two interventions consisting of two interface types: informational and experiential. The SPSS Graduate Pack 10.0 for Windows was used for data analysis and statistical reporting in this study. A t test was conducted to determine if a difference existed between the two interface means. ANOVA was conducted to determine if there was an interaction between the interface group means and the demographic data factored among the five dependent variables. Results of this study indicated that students at the University of Central Florida reported no differences between the two interface types. It was postulated that the informational interface would yield a higher mean score because of its implementation of HCI guidelines, conventions, and standards. However, it was concluded that the informational interface may not be a more usable interface. Users may be as inclined to use the experiential interface as the informational interface.
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Date Issued: 2005
Identifier: CFE0000807, ucf:46678
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0000807

Title: REALNAV: EXPLORING NATURAL USER INTERFACES FOR LOCOMOTION IN VIDEO GAMES.
Creator: Williamson, Brian, LaViola, Joseph, University of Central Florida
Abstract / Description: We present an exploration into realistic locomotion interfaces in video games using spatially convenient input hardware. In particular, we use Nintendo Wii Remotes to create natural mappings between user actions and their representation in a video game. Targeting American Football video games, we used the role of the quarterback as an exemplar since the game player needs to maneuver effectively in a small area, run down the field, and perform evasive gestures such as spinning, jumping, or the...
Show moreWe present an exploration into realistic locomotion interfaces in video games using spatially convenient input hardware. In particular, we use Nintendo Wii Remotes to create natural mappings between user actions and their representation in a video game. Targeting American Football video games, we used the role of the quarterback as an exemplar since the game player needs to maneuver effectively in a small area, run down the field, and perform evasive gestures such as spinning, jumping, or the "juke". In our study, we developed three locomotion techniques. The first technique used a single Wii Remote, placed anywhere on the user's body, using only the acceleration data. The second technique just used the Wii Remote's infrared sensor and had to be placed on the user's head. The third technique combined a Wii Remote's acceleration and infrared data using a Kalman filter. The Wii Motion Plus was also integrated to add the orientation of the user into the video game. To evaluate the different techniques, we compared them with a cost effective six degree of freedom (6DOF) optical tracker and two Wii Remotes placed on the user's feet. Experiments were performed comparing each to this technique. Finally, a user study was performed to determine if a preference existed among these techniques. The results showed that the second and third technique had the same location accuracy as the cost effective 6DOF tracker, but the first was too inaccurate for video game players. Furthermore, the range of the Wii remote infrared and Motion Plus exceeded the optical tracker of the comparison technique. Finally, the user study showed that video game players preferred the third method over the second, but were split on the use of the Motion Plus when the tasks did not require it.
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Date Issued: 2009
Identifier: CFE0002938, ucf:47956
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0002938

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