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Title: a priori synthetic sampling for increasing classification sensitivity in imbalanced data sets.
Creator: Rivera, William, Xanthopoulos, Petros, Wiegand, Rudolf, Karwowski, Waldemar, Kincaid, John, University of Central Florida
Abstract / Description: Building accurate classifiers for predicting group membership is made difficult when data is skewedor imbalanced which is typical of real world data sets. The classifier has the tendency to be biased towards the over represented group as a result. This imbalance is considered a class imbalance problem which will induce bias into the classifier particularly when the imbalance is high.Class imbalance data usually suffers from data intrinsic properties beyond that of imbalance alone.The problem...
Show moreBuilding accurate classifiers for predicting group membership is made difficult when data is skewedor imbalanced which is typical of real world data sets. The classifier has the tendency to be biased towards the over represented group as a result. This imbalance is considered a class imbalance problem which will induce bias into the classifier particularly when the imbalance is high.Class imbalance data usually suffers from data intrinsic properties beyond that of imbalance alone.The problem is intensified with larger levels of imbalance most commonly found in observationalstudies. Extreme cases of class imbalance are commonly found in many domains including frauddetection, mammography of cancer and post term births. These rare events are usually the mostcostly or have the highest level of risk associated with them and are therefore of most interest.To combat class imbalance the machine learning community has relied upon embedded, data preprocessing and ensemble learning approaches. Exploratory research has linked several factorsthat perpetuate the issue of misclassification in class imbalanced data. However, there remainsa lack of understanding between the relationship of the learner and imbalanced data among thecompeting approaches. The current landscape of data preprocessing approaches have appeal dueto the ability to divide the problem space in two which allows for simpler models. However, mostof these approaches have little theoretical bases although in some cases there is empirical evidence supporting the improvement.The main goals of this research is to introduce newly proposed a priori based re-sampling methodsthat improve concept learning within class imbalanced data. The results in this work highlightthe robustness of these techniques performance within publicly available data sets from differentdomains containing various levels of imbalance. In this research the theoretical and empiricalreasons are explored and discussed.
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Date Issued: 2015
Identifier: CFE0006169, ucf:51129
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006169

Title: A Simulation-Based Task Analysis using Agent-Based, Discrete Event and System Dynamics simulation.
Creator: Angelopoulou, Anastasia, Karwowski, Waldemar, Kincaid, John, Xanthopoulos, Petros, Hancock, Peter, University of Central Florida
Abstract / Description: Recent advances in technology have increased the need for using simulation models to analyze tasks and obtain human performance data. A variety of task analysis approaches and tools have been proposed and developed over the years. Over 100 task analysis methods have been reported in the literature. However, most of the developed methods and tools allow for representation of the static aspects of the tasks performed by expert system-driven human operators, neglecting aspects of the work...
Show moreRecent advances in technology have increased the need for using simulation models to analyze tasks and obtain human performance data. A variety of task analysis approaches and tools have been proposed and developed over the years. Over 100 task analysis methods have been reported in the literature. However, most of the developed methods and tools allow for representation of the static aspects of the tasks performed by expert system-driven human operators, neglecting aspects of the work environment, i.e. physical layout, and dynamic aspects of the task. The use of simulation can help face the new challenges in the field of task analysis as it allows for simulation of the dynamic aspects of the tasks, the humans performing them, and their locations in the environment. Modeling and/or simulation task analysis tools and techniques have been proven to be effective in task analysis, workload, and human reliability assessment. However, most of the existing task analysis simulation models and tools lack features that allow for consideration of errors, workload, level of operator's expertise and skills, among others. In addition, the current task analysis simulation tools require basic training on the tool to allow for modeling the flow of task analysis process and/or error and workload assessment. The modeling process is usually achieved using drag and drop functionality and, in some cases, programming skills.This research focuses on automating the modeling process and simulating individuals (or groups of individuals) performing tasks in a dynamic work environment in any domain. The main objective of this research is to develop a universal tool that allows for modeling and simulation of task analysis models in a short amount of time with limited need for training or knowledge of modeling and simulation theory. A Universal Task Analysis Simulation Modeling (UTASiMo) tool can be used for automatically generating simulation models that analyze the tasks performed by human operators. UTASiMo is a multi-method modeling and simulation tool developed as a combination of agent-based, discrete event, and system dynamics simulation models. A generic multi-method modeling and simulation framework, named 3M(&)S Framework, as well as the Unified Modeling Language have been used for the design of the conceptual model and the implementation of the simulation tool. UTASiMo-generated models are dynamically created during run-time based on user inputs. The simulation results include estimations of operator workload, task completion time, and probability of human errors based on human operator variability and task structure.
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Date Issued: 2015
Identifier: CFE0006252, ucf:51040
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006252

Title: Streamlining the Acquisition Process: Systems Analysis for Improving Army Acquisition Corps Officer Management.
Creator: Chu-Quinn, Shawn, Kincaid, John, Wiegand, Rudolf, Mohammad, Syed, University of Central Florida
Abstract / Description: The Army Acquisition Officer lacks proficient experience needed to fill key leadership positions within the Acquisition Corps. The active duty Army officer is considered for the Acquisition Corps functional area between their 5th and 9th years of service as an officer (-) after completing initial career milestones. The new Acquisition Corps officer is the rank of senior Captain or Major when he arrives to his first acquisition assignment with a proficiency level of novice (in acquisition)....
Show moreThe Army Acquisition Officer lacks proficient experience needed to fill key leadership positions within the Acquisition Corps. The active duty Army officer is considered for the Acquisition Corps functional area between their 5th and 9th years of service as an officer (-) after completing initial career milestones. The new Acquisition Corps officer is the rank of senior Captain or Major when he arrives to his first acquisition assignment with a proficiency level of novice (in acquisition). The Army officer may be advanced in his primary career branch, but his level decreases when he is assigned into the Acquisition Corps functional area. The civilian grade equivalent to the officer is a GS-12 or GS-13 whose proficiency level is advanced in his career field. The purpose of this study is to use a systems analysis approach to decompose the current acquisition officer professional development system, in order to study how well the current active duty officer flow works and how well it interacts or influences an acquisition officer's professional development; and to propose a potential solution to assist in the management of Army acquisition officers, so they gain proficiency through not only education and training, but also the hands-on experience that is needed to fill key leadership positions in the Army Acquisition Corps. An increased proficiency and proven successful track record in the acquisition workforce is the basis to positively affect acquisition streamlining processes within the Department of Defense by making good decisions through quality experience.
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Date Issued: 2015
Identifier: CFE0005590, ucf:50254
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005590

Title: Investigating Simulation-Based Pattern Recognition Training For Behavior Cue Detection.
Creator: Maraj, Crystal, Lackey, Stephanie, Kincaid, John, Shumaker, Randall, Keebler, Joseph, University of Central Florida
Abstract / Description: The U.S. military uses pattern recognition training to observe anomalies in human behavior. An examination of the pattern recognition training literature for Warfighters reveals a gap in training to discern patterns of human behavior in live environments. Additionally, the current state of warfare is evolving and requires operations to change. As a result, pattern recognition training must accommodate new practices to improve performance. A technique used to improve memory for identifying...
Show moreThe U.S. military uses pattern recognition training to observe anomalies in human behavior. An examination of the pattern recognition training literature for Warfighters reveals a gap in training to discern patterns of human behavior in live environments. Additionally, the current state of warfare is evolving and requires operations to change. As a result, pattern recognition training must accommodate new practices to improve performance. A technique used to improve memory for identifying patterns in the environment is Kim's game. Kim's game establishes patterns to identify inanimate objects, of which information retains in memory for later recall. The paper discusses the fundamental principles of Kim's game applied to virtual Simulation-Based Training. The virtual version of Kim's game contains customized scenarios for training behavior cue analysis. Virtual agents display kinesic cues that exhibit aggressive (i.e., slap hands and clench fist) and nervous behaviors including wring hands and check six. This research takes a novel approach by animating the kinesics cues in the virtual version of Kim's game for pattern recognition training. Detection accuracy, response time, and false positive detection serve as the performance data for analysis. Additional survey data collected include engagement, flow, and simulator sickness. All collected data was compared to a control condition to examine its effectiveness of behavior cue detection. A series of one-way between subjects design ANOVA's were conducted to examine the differences between Kim's game and control on post-test performance. Although, the results from this experiment showed no significance in post-test performance, the percent change in post-test performance provide further insight into the results of the Kim's game and control strategies. Specifically, participants in the control condition performed better than the Kim's game group on detection accuracy and response time. However, the Kim's game group outperformed the control group on false positive detection. Further, this experiment explored the differences in Engagement, Flow, and Simulator Sickness after the practice scenario between Kim's game group and the control group. The results found no significant difference in Engagement, partial significance for Flow, and significant difference for Simulator Sickness between the Kim's game and control group after the practice scenario. Next, a series of Spearman's rank correlations were conducted to assess the relationships between Engagement, Flow, Simulator Sickness, and post-test performance, as well as examine the relationship between working memory and training performance; resulting in meaningful correlations to explain the relationships and identifying new concepts to explain unrelated variables. Finally, the role of Engagement, Flow, and Simulator Sickness as a predictor of post-test performance was examined using a series of multiple linear regressions. The results highlighted Simulator Sickness as a significant predictor of post-test performance. Overall, the results from this experiment proposes to expand the body of pattern recognition training literature by identifying strategies that enhance behavior cue detection training. Furthermore, it provides recommendations to training and education communities for improving behavior cue analysis. ?
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Date Issued: 2015
Identifier: CFE0005659, ucf:50166
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005659

Title: Impacts of Complexity and Timing of Communication Interruptions on Visual Detection Tasks.
Creator: Stader, Sally, Mouloua, Mustapha, Hancock, Peter, Neider, Mark, Kincaid, John, University of Central Florida
Abstract / Description: Auditory preemption theory suggests two competing assumptions for the attention-capturing and performance-altering properties of auditory tasks. In onset preemption, attention is immediately diverted to the auditory channel. Strategic preemption involves a decision process in which the operator maintains focus on more complex auditory messages. The limitation in this process is that the human auditory, or echoic, memory store has a limit of 2 to 5 seconds, after which the message must be...
Show moreAuditory preemption theory suggests two competing assumptions for the attention-capturing and performance-altering properties of auditory tasks. In onset preemption, attention is immediately diverted to the auditory channel. Strategic preemption involves a decision process in which the operator maintains focus on more complex auditory messages. The limitation in this process is that the human auditory, or echoic, memory store has a limit of 2 to 5 seconds, after which the message must be processed or it decays. In contrast, multiple resource theory suggests that visual and auditory tasks may be efficiently time-shared because two different pools of cognitive resources are used. Previous research regarding these competing assumptions has been limited and equivocal. Thus, the current research focused on systematically examining the effects of complexity and timing of communication interruptions on visual detection tasks. It was hypothesized that both timing and complexity levels would impact detection performance in a multi-task environment. Study 1 evaluated the impact of complexity and timing of communications occurring before malfunctions in an ongoing visual detection task. Twenty-four participants were required to complete each of the eight timing blocks that included simple or complex communications occurring simultaneously, and at 2, 5, or 8 seconds before detection events. For simple communications, participants repeated three pre-recorded words. However, for complex communications, they generated three words beginning with the same last letter of a word prompt. Results indicated that complex communications at two seconds or less occurring before a visual detection event significantly impacted response time with a 1.3 to 1.6 second delay compared to all the other timings. Detection accuracy for complex communication tasks under the simultaneous condition was significantly degraded compared to simple communications at five seconds or more prior to the task. This resulted in a 20% decline in detection accuracy. Additionally, participants' workload ratings for complex communications were significantly higher than simple communications. Study 2 examined the timing of communications occurring at the corresponding seconds after the visual detection event. Twenty-four participants were randomly assigned to the communication complexity and timing blocks as in study 1. The results did not find significant performance effects of timing or complexity of communications on detection performance. However the workload ratings for the 2 and 5 second complex communication presentations were higher compared to the same simple communication conditions. Overall, these findings support the strategic preemption assumption for well-defined, complex communications. The onset preemption assumption for simple communications was not supported. These results also suggest that the boundaries of the multiple resource theory assumption may exist up to the limits of the echoic memory store. Figures of merit for task performance under the varying levels of timing and complexity are presented. Several theoretical and practical implications are discussed.
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Date Issued: 2014
Identifier: CFE0005420, ucf:50415
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005420

Title: The Effect of Habitat for Humanity Homeownership on Student Attendance and Standardized Test Scores in Orange County Florida School District.
Creator: Harris, Charles, Kincaid, John, Uddin, Nizam, Rivers, Kenyatta, Wiegand, Rudolf, University of Central Florida
Abstract / Description: The mobility of low-income students who do not have access to stable housing creates numerous challenges both at home and in school. Among these challenges, academic performance certainly is one of the most important. The lack of a more permanent, familiar, and safe environment is presumed to impact home life as well as students' performance in the classroom. This research compares two groups of current and former students of Orange County Public Schools (OCPS) in Florida (1) children of...
Show moreThe mobility of low-income students who do not have access to stable housing creates numerous challenges both at home and in school. Among these challenges, academic performance certainly is one of the most important. The lack of a more permanent, familiar, and safe environment is presumed to impact home life as well as students' performance in the classroom. This research compares two groups of current and former students of Orange County Public Schools (OCPS) in Florida (1) children of families who are Habitat for Humanity (HFH) homeowners, and (2) a matched socioeconomic control group. The HFH program is designed to provide a stable, affordable housing for families who cannot acquire it through standard means. The research question is: Does stability in housing make an impact on academic performance in the particular area of FCAT scores and attendance? Data were gathered from OCPS and the HFH homeowners themselves. This data were used to evaluate the impact of HFH homeownership on students' academic environment. Results showed better attendance at school, but HFH students fared worse in FCAT performance when compared to control group especially in reading.
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Date Issued: 2014
Identifier: CFE0005504, ucf:50360
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005504

Title: A Dynamic Enrollment Simulation Model for Planning and Decision-Making in a University.
Creator: Robledo, Luis, Sepulveda, Jose, Kincaid, John, Armacost, Robert, Archer, Sandra, University of Central Florida
Abstract / Description: Decision support systems for university management have had limited improvement in the incorporation of new cutting-edge techniques. Most decision-makers use traditional forecasting methods to base their decisions in order to maintain financially affordable programs and keep universities competitive for the last few decades. Strategic planning for universities has always been related to enrollment revenues, and operational expenses. Enrollment models in use today are able to represent...
Show moreDecision support systems for university management have had limited improvement in the incorporation of new cutting-edge techniques. Most decision-makers use traditional forecasting methods to base their decisions in order to maintain financially affordable programs and keep universities competitive for the last few decades. Strategic planning for universities has always been related to enrollment revenues, and operational expenses. Enrollment models in use today are able to represent forecasting based on historical data, considering usual variables like student headcount, student credit, among others. No consideration is given to students' preferences. Retention models, associated to enrollment, deal with average retention times leaving off preferences as well.Preferences play a major role at institutions where students are not required to declare their intentions (major) immediately. Even if they do, they may change it if they find another, more attractive major, or they may even decide to leave college for external reasons.Enrollment models have been identified to deal with three main purposes: prediction of income from tuition (in-state, out-of-state), planning of future courses and curriculum, and allocation of resources to academic departments, This general perspective does not provide useful information to faculty and Departments for detailed planning and allocation of resources for the next term or year. There is a need of new metrics to help faculty and Departments to reach a detailed and useful level in order to effectively plan this allocation of resources. The dynamics in the rate-of-growth, the preferences students have for certain majors at a specific point of time, or economic hardship make a difference when decisions have to be made for budgets requests, hiring of faculty, classroom assignment, parking, transportation, or even building new facilities. Existing models do not make difference between these variables.This simulation model is a hybrid model that considers the use of System Dynamics, Discrete-event and Agent-based simulation, which allows the representation of the general enrollment process at the University level (strategic decisions), and enrollment, retention and major selection at the College (tactical decisions) and Department level (operational decisions). This approach allows lower level to more accurately predict the number of students retained for next term or year, while allowing upper levels to decide on new students to admit (first time in college and transfers) and results in recommendations on faculty hiring, class or labs assignment, and resource allocation.This model merges both high and low levels of student's enrollment models into one application, allowing not only representation of the current overall enrollment, but also prediction at the College and Department level. This provides information on optimal classroom assignments, faculty and student resource allocation.
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Date Issued: 2013
Identifier: CFE0005055, ucf:49970
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005055

Title: How many are out there? A novel approach for open and closed systems.
Creator: Rehman, Zia, Kincaid, John, Wiegand, Rudolf, Finch, Craig, Uddin, Nizam, University of Central Florida
Abstract / Description: We propose a ratio estimator to determine population estimates using capture-recapture sampling. It's different than traditional approaches in the following ways:(1)Ordering of recaptures: Currently data sets do not take into account the "ordering" of the recaptures, although this crucial information is available to them at no cost. (2)Dependence of trials and cluster sampling: Our model explicitly considers trials to be dependent and improves existing literature which assumes independence. ...
Show moreWe propose a ratio estimator to determine population estimates using capture-recapture sampling. It's different than traditional approaches in the following ways:(1)Ordering of recaptures: Currently data sets do not take into account the "ordering" of the recaptures, although this crucial information is available to them at no cost. (2)Dependence of trials and cluster sampling: Our model explicitly considers trials to be dependent and improves existing literature which assumes independence. (3)Rate of convergence: The percentage sampled has an inverse relationship with population size, for a chosen degree of accuracy. (4)Asymptotic Attainment of Minimum Variance (Open Systems: (=population variance).(5)Full use of data and model applicability (6)Non-parametric (7)Heterogeneity: When units being sampled are hard to identify. (8)Open and closed systems: Simpler results are presented separately for closed systems.(9)Robustness to assumptions in open systems
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Date Issued: 2014
Identifier: CFE0005403, ucf:50411
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005403

Title: The Perception and Measurement of Human-Robot Trust.
Creator: Schaefer, Kristin, Hancock, Peter, Jentsch, Florian, Kincaid, John, Reinerman, Lauren, Billings, Deborah, Lee, John, University of Central Florida
Abstract / Description: As robots penetrate further into the everyday environments, trust in these robots becomes a crucial issue. The purpose of this work was to create and validate a reliable scale that could measure changes in an individual's trust in a robot. Assessment of current trust theory identified measurable antecedents specific to the human, the robot, and the environment. Six experiments subsumed the development of the 40 item trust scale. Scale development included the creation of a 172 item pool. Two...
Show moreAs robots penetrate further into the everyday environments, trust in these robots becomes a crucial issue. The purpose of this work was to create and validate a reliable scale that could measure changes in an individual's trust in a robot. Assessment of current trust theory identified measurable antecedents specific to the human, the robot, and the environment. Six experiments subsumed the development of the 40 item trust scale. Scale development included the creation of a 172 item pool. Two experiments identified the robot features and perceived functional characteristics that were related to the classification of a machine as a robot for this item pool. Item pool reduction techniques and subject matter expert (SME) content validation were used to reduce the scale to 40 items. The two final experiments were then conducted to validate the scale. The finalized 40 item pre-post interaction trust scale was designed to measure trust perceptions specific to HRI. The scale measured trust on a 0-100% rating scale and provides a percentage trust score. A 14 item sub-scale of this final version of the test recommended by SMEs may be sufficient for some HRI tasks, and the implications of this proposition were discussed.
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Date Issued: 2013
Identifier: CFE0004931, ucf:49634
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004931

Title: An Agile Roadmap for Live, Virtual and Constructive-Integrating Training Architecture (LVC-ITA): A Case Study Using a Component based Integrated Simulation Engine.
Creator: Park, Tae Woong, Lee, Gene, Rabelo, Luis, Elshennawy, Ahmad, Kincaid, John, University of Central Florida
Abstract / Description: Conducting seamless Live Virtual Constructive (LVC) simulation remains the most challenging issue of Modeling and Simulation (M(&)S). There is a lack of interoperability, limited reuse and loose integration between the Live, Virtual and/or Constructive assets across multiple Standard Simulation Architectures (SSAs). There have been various theoretical research endeavors about solving these problems but their solutions resulted in complex and inflexible integration, long user-usage time and...
Show moreConducting seamless Live Virtual Constructive (LVC) simulation remains the most challenging issue of Modeling and Simulation (M(&)S). There is a lack of interoperability, limited reuse and loose integration between the Live, Virtual and/or Constructive assets across multiple Standard Simulation Architectures (SSAs). There have been various theoretical research endeavors about solving these problems but their solutions resulted in complex and inflexible integration, long user-usage time and high cost for LVC simulation. The goal of this research is to provide an Agile Roadmap for the Live Virtual Constructive-Integrating Training Architecture (LVC-ITA) that will address the above problems and introduce interoperable LVC simulation. Therefore, this research describes how the newest M(&)S technologies can be utilized for LVC simulation interoperability and integration. Then, we will examine the optimal procedure to develop an agile roadmap for the LVC-ITA.In addition, this research illustrated a case study using an Adaptive distributed parallel Simulation environment for Interoperable and reusable Model (AddSIM) that is a component based integrated simulation engine. The agile roadmap of the LVC-ITA that reflects the lessons learned from the case study will contribute to guide M(&)S communities to an efficient path to increase interaction of M(&)S simulation across systems.
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Date Issued: 2015
Identifier: CFE0005682, ucf:52867
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005682

Title: The Effects of Presentation Mode and Pace on Learning Immunology with Computer Simulation: A Cognitive Evaluation of a Multimedia Learning Resource.
Creator: Bradley-Radakovich, Kristy, Kincaid, John, Khaled, Annette, McDaniel, Rudy, Greenwood-Ericksen, Adams, University of Central Florida
Abstract / Description: Multimedia learning tools have the potential to benefit instructors and learners as supplemental learning materials. However, when such tools are designed inappropriately, this can increase cognitive taxation and impede learning, rendering the tools ineffective. Guided by the theoretical underpinnings provided by cognitive load theory and the cognitive theory of multimedia learning, this study sought to empirically evaluate the effectiveness of a multimedia simulation tool aimed at teaching...
Show moreMultimedia learning tools have the potential to benefit instructors and learners as supplemental learning materials. However, when such tools are designed inappropriately, this can increase cognitive taxation and impede learning, rendering the tools ineffective. Guided by the theoretical underpinnings provided by cognitive load theory and the cognitive theory of multimedia learning, this study sought to empirically evaluate the effectiveness of a multimedia simulation tool aimed at teaching immunology to novices in an instructional setting. The instructional mode and pace of the tool were manipulated, the three levels of each variable yielding nine experimental groups. The effects of mode and pace on workload and learning scores were observed. The results of this study did not support the theory-driven hypotheses. No significant learning gains were found between the configuration groups, however overall significant learning gains were subsequently found when disregarding mode and pace configuration. Pace was found to influence workload such that fast pace presentations significantly increased workload ratings and a significant interaction of mode and pace was found for workload ratings. The findings suggest that the learning material was too high in intrinsic load and the working memory of the learners too highly taxed for the benefits of applying the design principles to be observed. Results also illustrate a potential exception to the conditions of the design principles when complex terminology is to be presented. Workload findings interpreted in the context of stress adaptation potentially indicate points at which learners at maximum capacity begin to exhibit performance decrements.
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Date Issued: 2011
Identifier: CFE0004090, ucf:49150
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004090

Title: Analyzing action game players' performance during distracted driving.
Creator: Rupp, Michael, Smither, Janan, Mouloua, Mustapha, Mcconnell, Daniel, Kincaid, John, University of Central Florida
Abstract / Description: Driving is a complex task that is highly reliant on attention. Research states that distrac-tions cause performance errors thus it is important to find ways to reduce driver distraction or assist drivers with ways to improve their cognitive resources if distraction is unavoidable. Moreover, research indicates that action video game players outperform non-players on lab-based tests of visual and cognitive abilities. However, research also exists that is contrary to these find-ings. Some...
Show moreDriving is a complex task that is highly reliant on attention. Research states that distrac-tions cause performance errors thus it is important to find ways to reduce driver distraction or assist drivers with ways to improve their cognitive resources if distraction is unavoidable. Moreover, research indicates that action video game players outperform non-players on lab-based tests of visual and cognitive abilities. However, research also exists that is contrary to these find-ings. Some researchers suggest that methodological deficiencies could be the cause of the significant findings in the literature. With such fervor of debate on the subject, the question re-mains of whether players acquire skills through playing action video games and if so can these games be used as research or training tools to enhance performance on realistic tasks. To answer this question, 45 male participants were tested using psychometric measures of spatial ability (Spatial orientation and visualization) and failures of attention (Cognitive Failures Question-naire), and then all participants drove four 10-minute drives in a driving simulator. The first drive was a practice, followed by a control drive. Participants were then distracted using a hands free phone conversation. Following that, participants completed a final control drive. Both overall video game experience and action video game experience was positively related to higher spatial ability scores. Additionally, participants with higher action game experience exhibited fewer lane deviations during driving overall, but not during the distraction condition. On the other hand, participants with higher spatial ability scores exhibited fewer lane deviations during the distraction condition, but not during the control drives. Furthermore, action video game ex-perience was not significant on the Cognitive Failures Questionnaire. Therefore, it was conclud-ed that individuals who have higher action game experience do not show improvements on any abilities of attention tested in this study. However, higher experience action video game players may perform better in simulated environments than those with less experience.
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Date Issued: 2012
Identifier: CFE0004434, ucf:49360
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004434

Title: Homologous Pairing Through DNA Driven Harmonics - A Simulation Investigation.
Creator: Calloway, Richard, Proctor, Michael, Kincaid, John, Jaganathan, Balasubramanian, Gerber, Matthew, Chai, Xinqing, University of Central Florida
Abstract / Description: The objective of this research is to determine if a better understanding of the (")molecule of life("), deoxyribonucleic acid or DNA can be obtained through Molecular Dynamics (MD) modeling and simulation (M(&)S) using contemporary MD M(&)S. It is difficult to overstate the significance of the DNA molecule. The now-completed Human Genome Project stands out as the most significant testimony yet to the importance of understanding DNA. The Human Genome Project (HGP) enumerated many areas of...
Show moreThe objective of this research is to determine if a better understanding of the (")molecule of life("), deoxyribonucleic acid or DNA can be obtained through Molecular Dynamics (MD) modeling and simulation (M(&)S) using contemporary MD M(&)S. It is difficult to overstate the significance of the DNA molecule. The now-completed Human Genome Project stands out as the most significant testimony yet to the importance of understanding DNA. The Human Genome Project (HGP) enumerated many areas of application of genomic research including molecular medicine, energy sources, environmental applications, agriculture and livestock breeding to name just a few. (Science, 2008) In addition to the fact that DNA contains the informational blueprints for all life, it also exhibits other remarkable characteristics most of which are either poorly understood or remain complete mysteries. One of those completely mysterious characteristics is the ability of DNA molecules to spontaneously segregate with other DNA molecules of similar sequence. This ability has been observed for years in living organisms and is known as (")homologous pairing.(") It is completely reproducible in a laboratory and defies explanation. What is the underlying mechanism that facilitates long-range attraction between 2 double-helix DNA molecules containing similar nucleotide sequences? The fact that we cannot answer this question indicates we are missing a fundamental piece of information concerning the DNA bio-molecule. The research proposed herein investigated using the Nano-scale Molecular Dynamics NAMD (Phillips et al., 2005) simulator the following hypotheses:H(Simulate Observed Closure NULL) : = Current MD force field models when used to model DNA molecule segments, contain sufficient variable terms and parameters to describe and reproduce directed segregating movement (closure of the segments) as previously observed by the Imperial College team between two Phi X 174 DNA molecules. H(Resonance NULL) : = Current MD force field models when used to model DNA molecule segments in a condensed phased solvent contain sufficient variable terms and parameters to reproduce theorized molecular resonation in the form of frequency content found in water between the segments. H(Harmonized Resonance NULL) : = Current MD force field models of DNA molecule segments in a condensed phase solvent produce theorized molecular resonation in the form of frequency content above and beyond the expected normal frequency levels found in water between the segments. H(Sequence Relationship NULL): = The specific frequencies and amplitudes of the harmonized resonance postulated in H(Harmonized Resonance NULL) are a direct function of DNA nucleotide sequence. H(Resonance Causes Closure NULL) : = Interacting harmonized resonation produces an aggregate force between the 2 macro-molecule segments resulting in simulation of the same directed motion and segment closure as observed by the Imperial College team between two Phi X 174 DNA molecules. After nearly six months of molecular dynamic simulation for H(Simulate Observed Closure NULL) and H(Resonance Causes Closure NULL) no evidence of closure between two similar sequenced DNA segments was found. There exist several contributing factors that potentially affected this result that are described in detail in the Results section. Simulations investigating H( Resonance NULL), H(Harmonized Resonance NULL) and the emergent hypothesis H(Sequence Relationship NULL) on the other hand, revealed a rich selection of periodic pressure variation occurring in the solvent between simulated DNA molecules. About 20% of the power in Fourier coefficients returned by Fast Fourier Transforms performed on the pressure data was characterized as statistically significant and was located in less than 2% of the coefficients by count. This unexpected result occurred consistently in 5 different system configurations with considerable system-to-system variation in both frequency and magnitude. After careful analysis given the extent of our experiments the data was found to be in support of H( Resonance NULL), and H(Harmonized Resonance NULL) . Regarding the emergent hypothesis H(Sequence Relationship NULL), further analysis was done on the aggregate data set looking for correlation between nucleotide sequence and frequency/magnitude. Some of the results may be related to sequence but were insufficient to prove it. Overall the conflicting results were inconclusive so the hypothesis was neither accepted nor rejected. Of particular interest to future researchers it was noted that the computational simulations performed herein were NOT able to reproduce what we know actually happens in a laboratory environment. DNA segregation known to occur in-vitro during the Imperial College investigation did not occur in our simulation. Until this discrepancy is resolved MM simulation should not as yet be considered a suitable tool for further investigation of Homologous Chromosome Pairing. In Chapter 5 specific follow on research is described in priority of need addressing several new questions.
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Date Issued: 2011
Identifier: CFE0004472, ucf:49302
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004472

Title: Modeling Transport and Protein Adsorption in Microfluidic Systems.
Creator: Finch, Craig, Hickman, James, Kincaid, John, Lin, Kuo-Chi, Behal, Aman, Cho, Hyoung, University of Central Florida
Abstract / Description: This work describes theoretical advances in the modeling and simulation of microfluidic systems and demonstrates the practical application of those techniques. A new multi-scale model of the adsorption of hard spheres was formulated to bridge the gap between simulations of discrete particles and continuum fluid dynamics. A whispering gallery mode (WGM) biosensor was constructed and used to measure the kinetics of adsorption for two types of proteins on four different surfaces. Computational...
Show moreThis work describes theoretical advances in the modeling and simulation of microfluidic systems and demonstrates the practical application of those techniques. A new multi-scale model of the adsorption of hard spheres was formulated to bridge the gap between simulations of discrete particles and continuum fluid dynamics. A whispering gallery mode (WGM) biosensor was constructed and used to measure the kinetics of adsorption for two types of proteins on four different surfaces. Computational fluid dynamics was used to analyze the transport of proteins in the flow cell of the biosensor. Kinetic models of protein adsorption that take transport limitations into account were fitted to the experimental data and used to draw conclusions about the mechanisms of adsorption. Transport simulations were then applied to the practical problem of optimizing the design of a microfluidic bioreactor to enable (")plugs(") of fluid to flow from one chamber to the next with minimal dispersion. Experiments were used to validate the transport simulations. The combination of quantitative modeling and simulation and experiments led to results that could not have been achieved using either approach by itself. Simulation tools that accurately predict transport and protein adsorption will enable the rational design of microfluidic devices for biomedical applications.
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Date Issued: 2011
Identifier: CFE0004474, ucf:49313
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004474

Title: Bleeding Control Using Multiple Amputee Trauma Trainer in Medical Simulation: Comparison of Movement Versus Non-Movement in Training.
Creator: Allen, Christine, Kincaid, John, Schatz, Sarah, Allred, Kelly, Talbert, Steven, Sotomayor, Teresita, University of Central Florida
Abstract / Description: Army first responders, specifically Combat Medics and Combat Lifesavers, provide medical intervention while in the field. Didactic as well as hands-on training helps to prepare these first responders, and one module they receive involves bleeding control. First responders are taught to use the Combat Application Tourniquet(&)#174; (CAT(&)#174;) to stop bleeding from limbs subjected to severe injury such as amputation, gunshot, or severe lacerations. A training aid like the Multiple Amputee...
Show moreArmy first responders, specifically Combat Medics and Combat Lifesavers, provide medical intervention while in the field. Didactic as well as hands-on training helps to prepare these first responders, and one module they receive involves bleeding control. First responders are taught to use the Combat Application Tourniquet(&)#174; (CAT(&)#174;) to stop bleeding from limbs subjected to severe injury such as amputation, gunshot, or severe lacerations. A training aid like the Multiple Amputee Trauma Trainer(TM) (MATT(TM)) simulator provides tourniquet training using a lifelike bilateral lower limb amputee. In addition, MATT(TM) combines movement and resistance while the first responder applies the tourniquet, mimicking conditions one would see in a real situation. This research describes tourniquet history, appropriate usage, field tourniquet review, surgical tourniquet, CAT(&)#174; bleeding intervention procedures, bleeding physiology and complications, prehospital tourniquet use in recent conflicts, medical simulation fidelity, and a review of the value of animatronic movement during tourniquet simulation-based training. I then evaluate the effectiveness of animatronic movement during tourniquet training using the Advanced MATT in an experiment using Army first responders. The control group experienced no movement while the experimental group experienced movement when applying a tourniquet during the lab-training. Each group then alternately experienced Advanced MATT movement during an immersive scenario along with fog, strobe lights, and battle sounds. It was hypothesized that 1) In the immersive scenario, the experimental groups (i.e., those who were trained on a moving simulator) would have a faster reaction time as compared to those participants who did not receive training on the moving Advanced MATT simulator; 2) In the lab-based training, the experimental groups would have a slower reaction time; 3) In the immersive scenario, the experimental groups would have a faster tourniquet application time when subjected to movement while in the lab-based training, but the experimental groups would also have a slower tourniquet application time when initially subjected to movement in the laboratory-based training; finally, 4, 5, and 6) Participants who completed lab-based tourniquet training on the Advanced MATT simulation with animatronic movement would report higher perceived realism scores than participants who complete the training on a static version of the Advanced MATT and participants who completed a tourniquet training immersive scenario on the Advanced MATT simulation with movement would report higher perceived realism, presence, and self-efficacy scores than participants who complete the training on a static version of the Advanced MATT. The empirical results show a significant overall training effect of the Advanced MATT simulator (with or without movement). For reaction time and tourniquet application time, involving simulator movement was significant over varying scenarios. A small reduction in reaction and tourniquet application time on the battlefield may be extremely beneficial on the battlefield. Participants who received movement generally gave more positive reactions than those who did not received movement, although these results failed to reach statistical significance. Participants who received movement, followed by a scenario without movement rated the subjective ratings the lowest, suggestive of the lack of movement. Furthermore, despite the order movement was received, no large drops in performance occurred in any condition, indicating that negative training was avoided.
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Date Issued: 2011
Identifier: CFE0004468, ucf:49316
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004468

Title: The use of video game achievements to enhance player performance, self-efficacy, and motivation.
Creator: Blair, Lucas, Bowers, Clint, Cannon-Bowers, Janis, McDaniel, Rudy, Kincaid, John, University of Central Florida
Abstract / Description: A taxonomy of achievement design features that exist currently in video game systems was created in order to evaluate the current the state of the art in achievement design. From the taxonomy of design features multiple mechanisms of action that influence player behavior were identified. These mechanisms lead to a predictive model that can guide the designs of achievements in order to improve performance, self-efficacy and motivation in players.Expected, unexpected, and incremental...
Show moreA taxonomy of achievement design features that exist currently in video game systems was created in order to evaluate the current the state of the art in achievement design. From the taxonomy of design features multiple mechanisms of action that influence player behavior were identified. These mechanisms lead to a predictive model that can guide the designs of achievements in order to improve performance, self-efficacy and motivation in players.Expected, unexpected, and incremental achievements were tested. Notifications occurring before and after earning an achievement were also tested. In addition to testing individual mechanisms of action a (")combined achievement(") was created with multiple mechanisms added that were hand-picked. For testing purposes the model was applied to achievements that were inserted into an instructional game. The results of the study revealed that individual mechanisms of action had little effect on players while multiple mechanisms in a combined achievement caused significant improvements in several categories. The limitations of the current study, as well as, plans for future study are also discussed.
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Date Issued: 2011
Identifier: CFE0004471, ucf:49297
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004471

Title: Exploration of the Impact of Affective Variables on Human Performance in a Live Simulation.
Creator: Westerlund, Ken, Kincaid, John, Sims, Valerie, Chin, Matthew, VanderVeen, Cornelius, University of Central Florida
Abstract / Description: Live simulations play an important role in allowing users to practice and develop skills they learn in training. Although live simulations are playing an increasingly important role in training, ways to improve them are not well understood or documented. In order to improve the efficacy of live simulation and maximize results from funds spent on training; this research examines the relationship between the affective variables of the participants and their performance in the live simulation....
Show moreLive simulations play an important role in allowing users to practice and develop skills they learn in training. Although live simulations are playing an increasingly important role in training, ways to improve them are not well understood or documented. In order to improve the efficacy of live simulation and maximize results from funds spent on training; this research examines the relationship between the affective variables of the participants and their performance in the live simulation. Prior to participating in the instructor development live simulation used in this study two training preference scales were administered to a group of trainees. These scales measured the trainees' locus of control and immersion tendencies. During the live simulation the trainees' performance was evaluated by a panel of expert observers. The trainees also self-reported their performance through the use of a self-rating instrument. Analysis of the data revealed significant positive correlations between the trainees' internal locus of control and their performance in the simulation, both self-reported (p=0.026) and as reported by the expert observers (p=0.033). The correlation between immersion tendency scores and performance in the live simulation were mixed; while not always statistically significant they did reveal some slight positive correlation. This research did provide a number of lessons learned and implications for instructional and simulation developers wishing to employ live simulation in a training environment. These include performance of sub-populations within the greater population of subjects, consideration of roles assigned to participants, and the need to increase presence within the live simulation. Application of these lessons learned can reduce training costs and/or improve the effectiveness of live simulation in a training environment, this in turn can be of significant benefit to instructional and simulation designers. Additionally, understanding these relationships can lead to better assignments of roles or activities within live simulation and improve the transfer of experience from live simulation training to on the job performance. However, additional research needs to be conducted in order to make more conclusive statements regarding the most appropriate affective variable that would allow for predicting transfer of the simulated experience to the 'real' world, the individuals who would benefit most from live simulation, and to develop additional prescriptive methods for improving live simulation utilized in training environments.
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Date Issued: 2013
Identifier: CFE0004958, ucf:49578
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004958

Title: Assessment of Terrain Database Correlation Using Line-Of-Sight Measurements.
Creator: Oyama, Leonardo, Goldiez, Brian, Kincaid, John, Graniela Ortiz, Benito, Martin, Glenn, University of Central Florida
Abstract / Description: The uncountable number of tools for the creation of synthetic terrains poses as a challenge for simulation interoperability. The permutations of tools, elevation maps, and software settings leads to combinations of poorly correlated virtual terrains. An important issue in distributed simulations is the lack of line-of-sight correlation. For example, in military networked simulations, consistent intervisibility between simulated entities is crucial for a fair-fight, especially when simulations...
Show moreThe uncountable number of tools for the creation of synthetic terrains poses as a challenge for simulation interoperability. The permutations of tools, elevation maps, and software settings leads to combinations of poorly correlated virtual terrains. An important issue in distributed simulations is the lack of line-of-sight correlation. For example, in military networked simulations, consistent intervisibility between simulated entities is crucial for a fair-fight, especially when simulations include direct-fire weapons. The literature review presented in the Chapter Two discusses a multitude of interoperability issues caused by discrepant terrain representations and rendering engines noncompliant to any standard image generation process. Furthermore, the literature review discusses past research that strived for measuring (or mitigating) the correlation issues between terrain databases. Based on previous research, this thesis proposes a methodology for analysis of line-of-sight correlation between a pair of terrain databases. All the mathematical theory involved in the methodology is discussed in the Chapter Three. In addition, this thesis proposes a new method for measuring the roughness of a visual terrain database. This method takes into account the 3D dispersion of the vectors normal to the polygons in the terrain's mesh. Because the vectors normal to the polygons are conveniently stored in most visual databases, the roughness calculation suggested here is fast and does not require sampling the terrain's elevation. In order to demonstrate the proposed method, twin terrain databases and a tool were created as part of this thesis. The goal of this tool is to extract data from the terrain databases for statistical analysis. The tool is open source and its source code is provided with this thesis. The Chapter Four includes an example of statistical analysis using an open source statistic software. The line-of-sight correlation analysis discussed here includes the terrain's geometry only (terrain's culture is not addressed). Human factors were not taken into consideration.
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Date Issued: 2015
Identifier: CFE0005985, ucf:50792
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005985

Title: Parallel Distributed Discrete Event Simulation Optimization Using Complexity and Deep Learning.
Creator: Cortes, Edwin, Rabelo, Luis, Lee, Gene, Kincaid, John, Elshennawy, Ahmad, University of Central Florida
Abstract / Description: Parallel distributed discrete event simulation (PDDES) is the execution of a discrete event simulation on a tightly or loosely coupled computer system with multiple processors. The discrete-event simulation model is decomposed into several logical processors (LPs) or simulation objects that can be executed concurrently using partitioning types such as spatial and temporal. PDDES is exceedingly important for the reduction of the simulation time, increase of model size, intellectual property...
Show moreParallel distributed discrete event simulation (PDDES) is the execution of a discrete event simulation on a tightly or loosely coupled computer system with multiple processors. The discrete-event simulation model is decomposed into several logical processors (LPs) or simulation objects that can be executed concurrently using partitioning types such as spatial and temporal. PDDES is exceedingly important for the reduction of the simulation time, increase of model size, intellectual property issue mitigation in multi-enterprise simulations, and the sharing of resources.One of the problems with PDDES is the time management to provide flow control over event processing, the process flow, and the coordination of different logical processors to take advantage of parallelism. Time Warp (TW), Breathing Time Buckets (BTB), and Breathing Time Warp (BTW) are three time management schemes studied by this research. For a particular PDDES problem, unfortunately, there is no clear methodology to decide a priori a time management scheme to achieve higher system and simulation performance.This dissertation shows a new approach for selecting the optimal time synchronization technique class that corresponds to a particular parallel distributed anddiscrete simulation with different levels of simulation logic complexity. Simulation complexities such as branching, parallelism, function calls, concurrency, iterations, mathematical computations, messaging frequency, event processing, and number of simulation objects interactions were given a weighted parameter value based on the cognitive weight approach. Deep belief neural networks were then used to perform deep learning from the simulation complexity parameters and their corresponding optimal time synchronization scheme value as measured by speedup performance.
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Date Issued: 2015
Identifier: CFE0006211, ucf:51114
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006211

Title: Understanding the Capabilities and Limitations of Advanced Interactive M(&)S: A Cricothyroidotomy Simulation Case Study.
Creator: Campbell-Wynn, Lillian, Proctor, Michael, Kincaid, John, Crumpton-Young, Lesia, Liu, Alan, Burgess, Deborah, University of Central Florida
Abstract / Description: Simulation for surgical education and training is increasingly perceived as a valuable contribution to traditional teaching methods providing a structured learning experience. Surgical simulations allow surgeons to practice tactics, techniques and procedures numerous times without the cost, limitations and ethical problems of using cadaver-based models. The goal of this research is to advance the use of modeling and simulation in support of emergency medical training. This research explores...
Show moreSimulation for surgical education and training is increasingly perceived as a valuable contribution to traditional teaching methods providing a structured learning experience. Surgical simulations allow surgeons to practice tactics, techniques and procedures numerous times without the cost, limitations and ethical problems of using cadaver-based models. The goal of this research is to advance the use of modeling and simulation in support of emergency medical training. This research explores questions identified through a case study of two different modeling and simulation techniques (-) virtual reality and mannequins - in the support of combat emergency medical education and training. To reduce the scope to a manageable dissertation, the research focuses on CricSim as representative form of virtual reality simulation and HapMed as a form of mannequin simulation both with haptic-enabled capabilities. To further narrow the scope, the research focuses on training of a medical technique common to both simulation systems, which for this research was the cricothyroidotomy airway management technique. The U.S. Army expressed interest in training of combat medics in the cricothyroidotomy airway management technique and offered to support experimentation with both facilities and trained combat medics as the sample population. An experiment supporting this research took place at Fort Indiantown Gap, a National Guard Training Center located in Annville, Lebanon County, Pennsylvania and is the home of the Medical Battalion Training Site. An advanced airway management course is augmented with combat medics receiving training and evaluation on performing the cricothyroidotomy procedure using CricSim and HapMed with system experts provided by each respective developer. The NASA Task Load survey is used to collect participants' assessment of workload in terms of Mental Demand, Physical Demand, Temporal Demand, Level of Effort, Performance and Level of Frustration based on four primary tasks of the cricothyroidotomy. Additionally, the Technology Acceptance Model survey is used to provide insight into participant's assessment of usability. Professional trainers also provide their assessment of the virtual simulators suitability in support of the combat medics in performing their tasks based on their standards. The results of the participants' assessment of each virtual simulator take the form of a comparison study. To improve the advancement of medical simulation in the training of cricothyroidotomy procedure, a summary of findings, generalized conclusions, lessons learned and recommendations for future research are illuminated. The dissertation team is comprised of medical experts within the U.S. Air Force Education and Training Command, U.S. Army Research and Medical Command, and the Uniformed Services University of the Health Sciences as well as simulation subject matter experts from the University of Central Florida.
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Date Issued: 2013
Identifier: CFE0005142, ucf:50705
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005142

simulation (10)	+ -
Simulation (6)	+ -
Modeling (4)	+ -
System Dynamics (4)	+ -
modeling (4)	+ -

training (4)	+ -
Serious Games (3)	+ -
learning (3)	+ -
workload (3)	+ -
Army (2)	+ -
Instructional Strategies (2)	+ -
MBSE (2)	+ -
Simulation-Based Training (2)	+ -
ALEKS (1)	+ -
ARPA (1)	+ -
ATC (1)	+ -
Acquisition (1)	+ -
Action Games (1)	+ -
AddSIM (1)	+ -
Agent Based (1)	+ -
Agent Based Simulation (1)	+ -
Agent-Based (1)	+ -
Apache (1)	+ -
Arbovirus (1)	+ -
Army Acquisition Corps (1)	+ -
Army Officer (1)	+ -
Asperger's (1)	+ -
Attendance (1)	+ -
Autism Spectrum Disorder (1)	+ -
C.R (1)	+ -

University of Central Florida (53)	+ -
Kincaid, John (52)	+ -
Karwowski, Waldemar (9)	+ -
Lee, Gene (7)	+ -
Wiegand, Rudolf (7)	+ -

Rabelo, Luis (6)	+ -
Shumaker, Randall (6)	+ -
Elshennawy, Ahmad (5)	+ -
Proctor, Michael (5)	+ -
Xanthopoulos, Petros (5)	+ -
Hancock, Peter (4)	+ -
Mouloua, Mustapha (4)	+ -
Bowers, Clint (3)	+ -
Cannon-Bowers, Janis (3)	+ -
Mcconnell, Daniel (3)	+ -
Mohammad, Syed (3)	+ -
Reinerman, Lauren (3)	+ -
Smither, Janan (3)	+ -
Sottilare, Robert (3)	+ -
Ahram, Tareq (2)	+ -
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Barber, Daniel (2)	+ -
Finch, Craig (2)	+ -
Geiger, Christopher (2)	+ -
Graniela Ortiz, Benito (2)	+ -
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Maxwell, Douglas (2)	+ -
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McDaniel, Thomas (2)	+ -
Mollaghasemi, Mansooreh (2)	+ -

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