VTechWorks Repository :: Browsing by Author "Tegarden, David P."

Browsing by Author "Tegarden, David P."

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Adaptive Life-Long Learning for an Inclusive Knowledge Economy
Arnold, Amy; Lindsey, Andrew; McCoy, Andrew P.; Khademian, Anne M.; Lockee, Barbara B.; Adams, Carol; Amelink, Catherine T.; Blankenship, Chip; Glover, Christopher; Harris, Chrystal; Hoyle, Clayton; Potts, Colin; Pike, Dale; Whittaker, Dale; Kjellsson, Daniel; Hare, David; Tegarden, David P.; Tinapple, David; Ucko, David; Nahapetian, Eta; Hou, Feng; Holmes, Glen A.; Keyel, Jared; Garrett, Jeff; Joo, Jenna; McPhee, Joel; Boyer, John D.; Flato, John; Lister, Jonothan; Haldane, Joseph; Greenwood, Julie; Sanders, Karen Eley; Bruce, Karla; Lindsey, Kate; Carlson, Kimberly; Wingfeld, Kristin; Hamilton, Laura; McNair, Lisa D.; Kamlet, Mark; Semmel, Marsha; Holt, Matthew; Richey, Michael; Kumar, Mukul; Spivy, Nene; Cardwell, Owen; Holloway, Rachel L.; Swearer, Randy; Hall, Ralph P.; Clark-Stallkamp, Rebecca; Mazer, Robert; Smith, Robert; Reynolds, Roger; Bess, Diego Scott; Weimer, Scott; Sagheb, Shahabedin; Garmise, Sheri; Ashburn, Sherrell; Johnson, Sylvester; Cardone, Taran; Nicewonger, Todd; Martin, Tom; Quick, Tom; Rikakis, Thanassis; Skuzinski, Thomas; Contomanolis, Manny (Calhoun Center for Higher Education Innovation, 2020-08-24)
This report addresses the globalized knowledge economy in the 21st century; not only as it exists today, but the knowledge economy needed to meet the demands of tomorrow. This report proposes that in order for our knowledge economy to grow and be sustainable, it must be inclusive in ways that enable it to adapt to—and incorporate within it—the personal and professional growth of a large and diverse body of lifelong learners. In this introduction, we first define what we mean by inclusive knowledge and explain how our proposed definition expands some of the traditional understandings. We then show that an expansive and dynamic conceptualization of knowledge increases inclusion and promotes lifelong adaptive learning as a mindset and a practice.
Athlete Monitoring in American Collegiate Football
Lewis, Marc Theron (Virginia Tech, 2021-03-17)
American football is one of the most popular sports in the United States. However, in comparison to other mainstream sports such as soccer and rugby, there is limited literature using scientific principles and theory to examine the most appropriate ways to monitor the sport. This serves as a barrier to American football practitioners in their development and implementation of evidence-based sport preparation programs. Therefore, the primary aim of this line of research (i.e., dissertation) is to illustrate the efficacy of commonly used athlete monitoring tools within the sport of American collegiate football, while proposing a systematic framework to guide the development of an athlete monitoring program. This aim was achieved through a series of studies with the following objectives: 1) to quantify the physical demands of American collegiate football practice by creating physiological movement profiles through the use of integrated microtechnology metrics and heart rate indices, 2) to determine the positional differences in the physical practice demands of American collegiate football athletes, 3) to examine which integrated microtechnology metrics might be used to most efficiently monitor the training load of American collegiate football athletes, 4) to demonstrate the suitability of using the countermovement jump (CMJ) to assess training adaptations in American collegiate football athletes through examining weekly changes in CMJ performance over the course of two 4-week periodized training blocks (8 weeks total), and 5) to examine the effect of acute fatigue on CMJ performance in American football athletes. The first study from this line of research quantified the physical demands of American collegiate football by position groups and found significant differences in both running based and non-running based training load metrics. In addition, the first study utilized a principal component analysis to determine 5 'principal' components that explain approximately 81% of the variance within the data. The second study utilized a univariate analysis and found significant changes in CMJ performance due the effect of time with significant improvements in CMJ 'strategy' variables over the training period. Finally, the third study used effects sizes to illustrate a larger magnitude of change in CMJ 'strategy' variables than CMJ 'output' variables due to effect of acute fatigue. Results from studies 2 and 3 suggest the importance of monitoring CMJ strategy variables when monitoring training adaptations and fatigue in American collegiate football athletes. This line of research provides practitioners with a systematic framework through which they can develop and implement evidence-based sport preparation programs within their own organizational context. In addition, this line of research provides practitioners with recommendations for which metrics to monitor when tracking training load in American collegiate football using integrated microtechnology. Finally, this line of research demonstrates how to assess training adaptations and fatigue using the CMJ within the sport of American collegiate football, while providing an empirical base through which the selection of CMJ variables can take place. Collectively, this line of research uses scientific principles and theory to extend the current literature in American collegiate football, while providing practitioners with a guide to athlete monitoring within the sport.
Capabilities Engineering:Promoting Change-Reduction and Constructing Change-Tolerant Systems
Ravichandar, Ramya (Virginia Tech, 2008-05-07)
We propose a Capabilities-based approach for constructing complex emergent systems such that they are change-tolerant, and the development effort promotes change-reduction. The inherent complexity of software systems increases their susceptibility to change when subjected to the vagaries of user needs, technology advances, market demands and other change inducing factors. Despite the inevitability of change, traditional Requirements Engineering strives to develop systems based on a fixed solution. This is a mostly unsuccessful approach as evidenced by the history of system failures. In contrast, we utilize Capabilities — functional abstractions that are neither as amorphous as user needs nor as rigid as system requirements — to architect systems to accommodate change with minimum impact. These entities are designed to exhibit desirable characteristics of high cohesion, low coupling and balanced abstraction levels. Capabilities are generated by a two-phased process called Capabilities Engineering. Phase I mathematically exploits the structural semantics of the Function Decomposition graph — a representation of user needs — to formulate change-tolerant Capabilities. Phase II optimizes these Capabilities to conform to schedule and technology constraints. Results from an empirical evaluation of a real-world Course Evaluation System indicate, with statistical significance, that a Capabilities-based design is more change-tolerant than a requirements-based design. In addition, we observe that the use of the CE process inherently reduces change, otherwise generated, during the regular development effort. Empirical analysis on the change-requests of Sakai, a complex emergent system, supports this claim. Finally, we observe that the process of Capabilities Engineering assists in pre-requirement specification traceability by bridging the complexity gap between the problem and solution spaces.
Design Readiness: An Exploratory Model of Object-Oriented Design Performance
Lewis, Tracy L. (Virginia Tech, 2004-07-16)
The available literature supports the fact that some students experience difficulty learning object-oriented design (OOD) principles. Previously explored predictors of OOD learning difficulties include student characteristics (cognitive activities, self-efficacy), teaching methodologies (teacher centered, course complexity), and student experiences (prior programming experience). Yet, within an extensive body of literature devoted to OOD, two explanations of student difficulty remain largely unexplored: (1) varying conceptualizations of the underlying principles/strategies of OOD, and (2) preparedness or readiness to learn OOD. This research also investigated the extent to which individual differences impacted DRAS and OOD performance. The individual difference measures of interest in this study included college grade point average, prior programming experience, cognitive abilities (spatial orientation, visualization, logical reasoning, flexibility, perceptual style), and design readiness. In addition, OOD performance was measured using two constructs: course grade (exams, labs, programs, overall), and a specially constructed design task. Participants selected from the CS2 course from two southeastern state universities were used within this study, resulting in a sample size of 161 (School A, n = 76; School B, n = 85). School A is a mid-sized comprehensive university and School B is a large research-intensive university. If was found that the schools significantly differed on all measures of prior computer science experience and cognitive abilities. Path analysis was conducted to determine which individual differences were related to design readiness and OOD performance. In summary, this research identified that instructors can not ignore individual differences when teaching OOD. It was found that the cognitive ability visualization, prior OO experience, and overall college grade point average should be considered when teaching OOD. As it stands, without identifying specific teaching strategies used at the schools within this study, this research implies that OOD may require a certain level of practical computer experience before OOD is introduced into the curriculum. The cognitive ability visualization was found to have a significant indirect relationship with overall course grade through the mediating variable design readiness. Further, the results suggest that the DRAS may serve as a viable instrument in identifying successful OOD students as well as students that require supplemental OOD instruction.
Detecting Transient Changes in Gait Using Fractal Scaling of Gait Variability in Conjunction with Gaussian Continuous Wavelet Transform
Jaskowak, Daniel Joseph (Virginia Tech, 2019-01-31)
Accelerometer data can be analyzed using a variety of methods which are effective in the clinical setting. Time-series analysis is used to analyze spatiotemporal variables in various populations. More recently, investigators have focused on gait complexity and the structure of spatiotemporal variations during walking and running. This study evaluated the use of time-series analyses to determine gait parameters during running. Subjects were college-age female soccer players. Accelerometer data were collected using GPS-embedded trunk-mounted accelerometers. Customized Matlab® programs were developed that included Gaussian continuous wavelet transform (CWT) to determine spatiotemporal characteristics, detrended fluctuation analysis (DFA) to examine gait complexity and autocorrelation analyses (ACF) to assess gait regularity. Reliability was examined using repeated running efforts and intraclass correlation. Proof of concept was determined by examining differences in each variable between various running speeds. Applicability was established by examining gait before and after fatiguing activity. The results showed most variables had excellent reliability. Test-retest R2 values for these variables ranged from 0.8 to 1.0. Low reliability was seen in bilateral comparisons of gait symmetry. Increases in running speed resulted in expected changes in spatiotemporal and acceleration variables. Fatiguing exercise had minimal effects on spatiotemporal variables but resulted in noticeable declines in complexity. This investigation shows that GPS-embedded trunk-mounted accelerometers can be effectively used to assess running gait. CWT and DFA yield reliable measures of spatiotemporal characteristics of gait and gait complexity. The effects of running speed and fatigue on these variables provides proof of concepts and applicability for this analytical approach.
Effectiveness Evaluation of COVID-19 Regulations in Collegiate Sports: Quantifying Player Proximity and Workload During Soccer Training
Andreano, Kylea Joelle (Virginia Tech, 2023-05-26)
The COVID-19 pandemic and subsequent shutdown and regulations have drastically altered the world of competitive sports. The global shutdown beginning in March 2020 put a significant strain on athlete's ability to train, as many fitness centers were closed to prevent disease transmission. When it was deemed that athletic competition was safe to resume, there were still strict regulations in place to support public health efforts. This retrospective study primarily aims to evaluate the effectiveness of COVID-19 safety regulations in competitive sports. Specifically, the successfulness to correctly implement social distancing guidelines is of high interest. A secondary aim of this study is to assess changes in workload during preseason training before COVID-19, during the time of heavily enforced COVID-19 regulations, and following strict COVID-19 restrictions, as workload can be a predictor of athletic injury. Participants in this study included Virginia Tech Women's Soccer athletes and data were analyzed from the first 9 preseason training sessions during the 2019, 2020, 2021 and 2022 seasons. Data were generated from participants wearing the STATSports Apex device during training. A custom MATLAB spatiotemporal program developed by the Williams Research Group was utilized to determine player proximity. Total distance (m) and high metabolic load (HMLD) (au), and high-speed distance (HSD) (m) metrics were analyzed to understand changes in participant workload. It was found that overall the Virginia Tech Women's Soccer Team's implementation of the guidelines was effective, as there were no invasion violations during the 2020 preseason sample.
The Effects of Business Process Management Cognitive Resources and User Cognitive Differences on Outcomes of User Comprehension
Swan, Bret R. (Virginia Tech, 2007-03-26)
There is a growing need to study factors that affect user comprehension of Business Process Management (BPM) information portrayed by graphical process models (GPMs). For example, deployment of BPM Systems, unique types of enterprise-level information systems, has dramatically increased in recent years. This increase is primarily because BPM Systems give a variety of managers across an enterprise the ability to directly design, configure, enact, monitor, diagnose, and control business processes that other types of enterprise systems do not. This is possible because BPM Systems uniquely rely on GPMs derived from formal graph theory. Besides controlling the business processes, these GPMs, such as metagraphs and Unified Modeling Language (UML) diagrams, portray business process information (BPI) and prompt BPM managers to apply their training and expertise to deal with BPM situations. As a result, GPMs are the primary information artifacts for decision-making and communication among different, often geographically dispersed stakeholders. Therefore, user comprehension of these unique GPMs is critical to the efficient and effective development, deployment, and utilization of BPM Systems. User comprehension outcomes are jointly affected by the (1) BPM cognitive resources available to each manager (including the type of GPM, BPI, and user educational training and experience), and (2) cognitive differences between individual BPM managers (such as their mental workload, cognitive styles and cognitive abilities). Although research has studied GPMs in various contexts, there is apparently no empirical research investigating GPM user comprehension in the context of BPM Systems. This research makes an important contribution by addressing this gap in the literature. Statement of the Objective: The purpose of this research is to empirically study how BPM cognitive resources and cognitive differences between individuals affect outcomes of GPM user comprehension. This research centered on the following objectives: A. Investigate whether more positive user comprehension outcomes are produced by novice users if a single GPM technique is used to portray different types of BPI (e.g., as with metagraphs) or if different GPM techniques are used to portray different types of BPI (e.g., as with UML diagrams). B. Investigate whether one type of BPI is more easily comprehended and interpreted by novice users irrespective of the type of GPM or the type of educational training of the user. C. Investigate whether users with a specific type of user educational training can more easily comprehend and interpret BPM information irrespective of the type of GPM or the type of BPI. D. Evaluate influences of individual cognitive differences (i.e., mental workload, cognitive styles, and cognitive abilities) on outcomes of user comprehension. In order to accomplish these objectives, this study: (a) defined a theoretical framework conceptualizing user comprehension outcomes in terms of the interaction between cognitive resources external to the user and individual differences affecting how users cognitively process BPI, (b) empirically tested an operational research model of GPM user comprehension that is based on the theoretical framework, and (c) interpreted the experimental results in the context of related literatures. Description of Research Methods: This study empirically tested relationships between several variables representing BPM cognitive resources and individual cognitive differences hypothesized as influencing the outcomes of user comprehension. A laboratory experiment, involving 87 upper-level undergraduate students from two universities, analyzed relationships between participant comprehension of two types of GPMs (i.e., metagraphs and UML diagrams) used to portray three types of BPI (i.e., task-centric, resource-centric, and information-centric BPI) by novice GPM users possessing different educational training (i.e., industrial engineering, business management, and computer science training). Dependent variables included assessments of task accuracy, task timeliness, subjective mental workload, and self-efficacy. Covariate effects were also analyzed for two types of participant cognitive abilities (i.e., general cognitive ability (GCA) and attentional abilities) and two types of participant cognitive styles (extroversion-introversion and sensing-intuitive). Multivariate analysis techniques were used to analyze and interpret the data. Discussion of Results: The type of GPM and participants' GCA produced significant effects on the dependent variables in this study. For example, metagraph users produced significantly more desirable results than UML users across all dependent variables, contrary to what was hypothesized. However, if only the BPM cognitive resources (i.e., GPM Type, BPM Type, and the Type of Participant Education) were studied in relation to user comprehension outcomes, spurious conclusions would have been reached. When individual cognitive differences were included in the research model and analyses, results showed participants with higher GCA produced significantly more positive user comprehension outcomes compared to participants with lower GCAs. Also, many of the impacts of differences in the types of BPI and the types of UET were moderated by the differences in participants' GCA and attentional abilities. In addition, the relationship between subjective mental workload and task performance (i.e., accuracy and timeliness) suggest a possible GPM cognitive "profile" for user comprehension tasks in a BPM Systems context. These results have important implications for future research and practice in several bodies of knowledge, including GPM user comprehension in management systems engineering, BPM modeling, BPM Systems, HCI, and cognitive ergonomics literature.
Explaining Developer Attitude Toward Using Formalized Commercial Methodologies: Decomposing Perceived Usefulness
Henderson, David Lockhart III (Virginia Tech, 2007-09-07)
Although methodology use generally leads to fewer software defects and reductions in development time, the introduction of a formalized systems development methodology is often met with substantial resistance. Motivated by the purported benefits of methodology use, yet resistance to the introduction of a methodology, this study explains developer attitude toward using a formalized commercial methodology. An important variable for explaining attitude is perceived usefulness, defined as the degree to which using a methodology will enhance a developer's job performance. If, however, a benefit of using a methodology is different than increased job performance, then limiting the definition of perceived usefulness to beliefs surrounding job performance may provide an incomplete representation of what makes a methodology useful to developers. A methodology may be perceived as a rational process, used to achieve objectives such as increasing job performance or as a political process used to achieve objectives particular to one person or group. In order to determine what makes a methodology useful to developers, the perceived usefulness construct was expanded to include benefits of methodology use related toward achieving political objectives. In addition to broadening the perceived usefulness construct, this research also broke down perceived usefulness into its referent dimensions. Decomposing perceived usefulness provided a deeper understanding of what makes a methodology useful to developers and revealed the relative importance of each dimension of perceived usefulness. The study surveyed 120 developers. Partial least squares regression was used to test the antecedents of developer attitude as well as the hypothesized structure of perceived usefulness. Results indicate that developers will have more favorable attitudes toward methodologies they perceive as useful, easy to use, and consistent with the way they like to develop systems. Additionally, findings suggest that developers may find methodologies not only useful for achieving rational goals such as increasing system quality, raising productivity, and enhancing communication, but also useful for achieving political goals such as increasing career opportunities, showing others that professional development practices are being used, reducing anxiety, and defending against unreasonable user demands.
Factors Related to Information Technology Implementation in the Malaysian Ministry of Education Polytechnics
Zakaria, Zulkifli (Virginia Tech, 2001-05-08)
The purpose of this study was to examine factors related to information technology (IT) implementation in the curriculum. The focus was on Malaysian Ministry of Education Polytechnic (MoEP) faculty members' attitudes toward IT, as well as IT availability and IT use in teaching. The response rate from the 332 surveys sent to the MoEP was 75.9%. Faculty members as a whole appeared to have readiness for adoption of changes related to IT use in teaching despite the lack of IT use in general. The use of selected IT items was skewed greatly in the direction of non-use. Faculty attitudes toward the use of IT in their teaching were very positive. The overall professional development experiences in IT that respondents had were greatly skewed toward non-participation. Results for items associated with supports services showed that they were available for faculty use. Sixty-nine percent of the respondents reported to face barriers to the use IT in their teaching. The extent of IT use in general for male respondents and female respondents showed a significant difference among gender. ANOVA revealed no difference between MoEP membership and IT use in general. Analysis of department membership and IT use in general revealed no difference between the two. Highest level of education had a low significant correlation with extent of IT use in general. A low negative correlation was shown between highest level of education and other demographic variables. Age had a moderate positive correlation with years served for the MoEP and a high correlation with years served for the MoE. Years served for the MoEP also has a moderate correlation with years served for the MoE. There were no significant correlations among variables except for online discussion and teaching load. Highest level of education showed a low correlation with email, WWW, and scanner. Multiple regression analysis was conducted to determine what variables were the best predictors of IT use. Results revealed an R2 of 0.04. Highest level of education contributed significantly to the variance. Adoption proneness proved to be a predictor for IT use in teaching, while other selected demographic variables were not significant predictors.
The Feasibility of Accelerometer-Derived Measures of Vertical Jump Height as a Marker of Neuromuscular Performance in Collegiate Soccer Players
Hines, Deena Sbitany (Virginia Tech, 2022-06-23)
In female college soccer players, there is no protocol for assessing fatigue. A total of 40 members of the Virginia Tech Women's Soccer team participated in the countermovement jump assessment to find a reliable way to gauge player fatigue and readiness in these athletes. These were tested by assessing the within and between-day similarity of a countermovement jump test as a measure of neuromuscular performance by comparing multiple jump heights during jumps performed within a single day and on separate days. Additionally, to determine the responsiveness of countermovement jump height as a marker of fatigue, we compared jump heights before and after activities thought to induce fatigue and competitive matches. All subjects wore a STATSports APEX unit that includes an 18Hz GPS, 952 Hz accelerometer, and 952 Hz gyroscope situated on the upper back over the second thoracic vertebra using a manufacturer-provided vest. After each training session or match, the data was downloaded using the manufacturer's software (APEXA). A custom MATLAB program was then used to calculate CMJ height from vertical acceleration. Results showed that CMJ heights were very reliable both within and between testing days. CMJ heights were found to accurately decrease following both high-load training sessions and a competitive soccer match. For both activities, the decrease in performance was dependent on the amount of load experienced. Lastly, CMJ height did not recover the day following high training load sessions. Across a training week, CMJ consistently decreased each day. This was followed by a recovery in performance following two off days. The results suggest that the use of a trunk-mounted, GPS-embedded accelerometer and a novel three-jump protocol is responsive to assess CMJ height. In addition, it is responsive to estimating fatigue following soccer activity.
Interactive prediction software for underlying multi-seam design
Kanniganti, Ravi S. (Virginia Tech, 1996-01-29)
An extensive review of multi-seam under-mining literature was conducted and a data base of case studies was compiled. A critical review of the design principles outlined in this literature resulted in the compilation of specific design criteria for the design of lower seam mines. Analysis of this criteria demonstrated the necessity for a protocol for the design of unsymmetrically loaded pillars. Such a design criteria was developed using finite element methods for a wide range of possible loading conditions. This design criteria can be utilized for underlying pillar design when the loading conditions can be determined. To facilitate using all the under-mining research results by field/planning engineers a Windows™ based software package was developed. This software package contains a multi-seam tutorial, analytical tools and a case history database. The software is very friendly and fully interactive and results of analysis can be verified against case study data included in the program.
Multidimensional Visualization of Process Monitoring and Quality Assurance Data in High-Volume Discrete Manufacturing
Teets, Jay Marshall (Virginia Tech, 2007-01-19)
Advances in microcomputing hardware and software over the last several years have resulted in personal computers with exceptional computational power and speed. As the costs associated with microcomputer hardware and software continue to decline, manufacturers have begun to implement numerous information technology components on the shop floor. Components such as microcomputer file servers and client workstations are replacing traditional (manual) methods of data collection and analysis since they can be used as a tool for real-time decision-making. Server-based and web-based shop floor data collection and monitoring software applications are able to collect vast amounts of data in a relatively short period of time. In addition, advances in telecommunications and computer interconnectivity allow for the remote access and sharing of this data for additional analysis. Rarely, however, does the method by which a manager reviews production and quality data keep pace with the large amount of data being collected and thus available for analysis. Visualization techniques that allow the decision maker to react quickly, such as the ability to view and manipulate vast amounts of data in real-time, may provide an alternative for operations managers and decision-makers. These techniques can be used to improve the communication between the manager using a microcomputer and the microcomputer itself through the use of computer-generated, domain-specific visualizations. This study explores the use of visualization tools and techniques applied to manufacturing systems as an aid in managerial decision-making. Numerous visual representations that support process and quality monitoring have been developed and presented for evaluation of process and product quality characteristics. These visual representations are based on quality assurance data and process monitoring data from a high-volume, discrete product manufacturer with considerable investment in both automated and intelligent processes and information technology components. A computer-based application was developed and used to display the visual representations that were then presented to a sample group of evaluators who evaluated them with respect to their ability to utilize them in making accurate and timely decisions about the processes being monitored. This study concludes with a summary of the results and provides a direction for future research efforts.
Programming Language and Tools for Automated Testing
Tan, Roy Patrick (Virginia Tech, 2007-08-08)
Software testing is a necessary and integral part of the software quality process. It is estimated that inadequate testing infrastructure cost the US economy between $22.2 and $59.5 billion. We present Sulu, a programming language designed with automated unit testing specifically in mind, as a demonstration of how software testing may be more integrated and automated into the software development process. Sulu's runtime and tools support automated testing from end to end; automating the generation, execution, and evaluation of test suites using both code coverage and mutation analysis. Sulu is also designed to fully integrate automatically generated tests with manually written test suites. Sulu's tools incorporate pluggable test case generators, which enables the software developer to employ different test case generation algorithms. To show the effectiveness of this integrated approach, we designed an experiment to evaluate a family of test suites generated using one test case generation algorithm, which exhaustively enumerates every sequence of method calls within a certain bound. The results show over 80\% code coverage and high mutation coverage for the most comprehensive test suite generated.
Quantifying validity and reliability of GPS derived distances during simulated tennis movements
Tessaro, Edoardo (Virginia Tech, 2017-02-09)
Tennis is a competitive sport attracting millions of players and fans worldwide. During a competition, the physical component crucially affects the final result of a match. In field sports such as soccer physical demand data are collected using the global positioning system (GPS). There is question regarding the validity and reliability of using GPS technology for court sports such as tennis. The purpose of this study is to determine the validity and reliability of GPS to determine distances covered during simulated tennis movements. This was done by comparing GPS recorded distances to distances determined with a calibrated trundle wheel. Two SPI HPU units were attached to the wheel Four different trials were performed to assess accuracy and reliability: distance trial (DIST), shuttle run trial (SHUT), change of direction trial (COD) and random movement trial (RAND). The latter three trials are performed on a tennis court and designed to mimic movements during a tennis match. Bland-Altman analysis showed that during all trails, there were small differences in the trundle wheel and GPS derived distances. Bias for the DIST, SHUT, COD and RAND trails were -0.02±0.10, -0.51±0.15, -0.24±0.19 and 0.28±0.20%, respectively. Root mean squared (RMS) errors for the four trials were 0.41±0.10, 1.28±0.10, 1.70±0.10 and 1.55±0.13%. Analysis of paired units showed a good reliability with mean bias and RMS errors <2%%. These results suggest that SPI HPU units are both accurate and reliable for simulated tennis movements. They can be confidently used to determine the physical demands of court sports like tennis.
Tibial Acceleration and Shock Attenuation in Female and Male Distance Runners at Different Levels of Body Weight Unloading
Leatham, Cheyenne Liahona (Virginia Tech, 2024-05-28)
Running popularity has led to a rise in chronic lower limb injuries resulting from cumulative loading. Many of these injuries are tibial stress fractures. Tibial accelerometers are commonly used to measure tibial stress and may even be predictive of injury at the distal limb. Lower body positive pressure (LBPP) treadmills have become increasingly popular amongst athletes and practitioners to prevent and treat lower limb injuries by reducing effective body weight (BW) through mechanical support. The purpose of this thesis is to investigate if BW unloading affects tibial acceleration (TA) and shock attenuation. Twelve trained distance runners (Sex: 6 males and 6 females; Age: 18-30 years) were recruited for this study. TA was measured through two Blue Trident, IMeasureU step units located at the distal tibiae. A STATSports Apex unit was also used to measure acceleration at the superior trunk and calculate shock attenuation for each limb. It was found that BW unloading had no discernable effect on mean peak TA and shock attenuation, bone stimulus, or contact time, regardless of running speed. However, a significant relationship was observed between running speed and both mean peak TA and bone stimulus where an increase in speed led to an increase in TA and bone stimulus. Furthermore, running speed did not affect shock attenuation or contact time. In conclusion, BW unloading did not alter gait kinematics in trained distance runners.
Toward a Theory of Information System Development Success: Perceptions of Software Development Team Members
Zelazny, Lucian M. (Virginia Tech, 2011-06-08)
This dissertation increases our understanding of information system project success by investigating how software development team members define the success of an information system development effort. The theoretical model of ISD success is developed and tested. ISD success is measured through the eyes of the software development team members—since they are the most influential stakeholders during the development of the system. This dissertation was conducted in two phases: 1) theory building and 2) theory testing. The theory building phase began with a thorough literature review. Semi-structured interviews were conducted and the data analyzed to add emergent concepts to the model. The result of the theory building phase is the theoretical model of ISD success. The theory testing stage began with the development and validation of a survey instrument to measure the constructs and subconstructs found within the theoretical model of ISD success. Data was collected and the model tested using partial least squares regression. The findings indicate that software development team members view ISD success as being composed of process quality, functional product quality, non-functional product quality, team member benefits, and team member satisfaction. Team member satisfaction is highly influenced by team member benefits, moderately influenced by functional product quality and slightly influence by non-functional product quality and process quality. Software development team members view process quality as being composed of within budget and process maturity; non-functional product as being composed of reliability, usability, testability, and efficiency; team member benefits as being composed of learning and teamwork; and team member satisfaction as being composed of product satisfaction, process satisfaction, and personal satisfaction. Software development team members do not view on time as a significant contributor to their definition of process quality; they do not view modifiability, portability, or reusability as significant contributors to their definition of non-functional product quality; and they do not view recognition as a significant contributor to team member benefits.
Use of a GPS-Embedded Accelerometer to Evaluate the Complexity of the Running Gait. Part 2: Effects of Fatiguing Activity
Tegarden, David P.; Williams, Jay H.; Jaskowak, Daniel J. (2019-01-03)
In the companion study, we report a new approach for analyzing gait complexity and the structure of gait variability (12). Previous studies show that the fractal scaling index (FSI) determined using detrended uctuation analysis (DFA) is reduced by neuromuscular disorders (6) as well as low back pain, fatigue, injury and overtraining (2, 5, 8, 10), indicating a less healthy gait (1). On the other hand, physical training increases DFA (9).
Use of Cross-Correlation Analysis to Determine Heart Rate Kinetics During Non-Steady State, Fatiguing Exercise in Collegiate Female Soccer Athletes
Williams, Brian Orbreyn (Virginia Tech, 2020-07-01)
For years, heart rate (HR) kinetics have been used as an indicator of training status and fatigue. Slowed kinetics indicate poor fitness and/or fatigue. In this study it was determined that HR kinetics can be reliably estimated during modeled, quasi-binary, and dynamic exercise using cross-correlation analysis of HR and external work rate. Heart rate and running speed were cross-correlated yielding a cross-correlation function (CCF) and analyzed for its peak (CCFmax) and time delay (CCFlag). Modeled exercise data where the time constants for HR (τ) increased from 2-120 sec. yielded linear decreases in CCFmax (r2 = 0.9949) and linear increases in CCFlag (r2=0.9996). A strong linear relationship existed between CCFmax and CCFlag (r2=0.9989). Steady-state exercise data produced strong relationships between the calculated τ and CCFmax (r2=0.8736) and CCFlag (r2=0.9061), and CCFmax and CCFlag showed a positive relationship (r2=0.7753). CCFmax between repeated sprint trials (R2=0.9123) and super set trails (R2=0.9227) were very similar. These results suggest good repeatability for both quasi-binary activity and random activity. To assess validity, CCFmax values during the sprint trials were compared to two standard field tests of fitness (Beep and Man U tests). There were strong relationships between CCFmax and distances covered during the Beep (r2=0.7911) and Mann U tests (r2=0.7770). Lastly, the applicability of the CCF method was applied to dynamic exercise, using data collected from competitive soccer matches. For the field players, significant reductions in CCFmax occurred during the first and second periods of the match. There was a significant relationship between the total distance covered during the match and the decline in CCFmax (r=-0.4297, p<0.05). Larger declines in CCFmax during the last 15 min of the match were also seen in the second match of a multiple match week compared to the first match. Tis later finding suggests that CCFmax may be a use tool to evaluate "fatigue" during dynamic exercise. Overall, cross-correlation of HR and running speed appears to be a reliable, valid and applicable approach to evaluate HR kinetics during exercise. As such, it may be beneficial for evaluating player fitness and readiness for competition.
The Use of Trunk-Mounted Accelerometers for Neurmuscular Testing in Collegiate Women's Soccer
Jaskowak, Daniel Joseph (Virginia Tech, 2021-06-02)
Team sports frequently use inertial measurement units (IMU) fixed at the scapulae for the quantification of athlete performance. Similar IMU are used in clinical settings for gait analysis and jump testing but are located at the center of mass (COM). For clinical methods of jump and gait analysis to be translated to sports related IMU, an investigation of the validity of measure from the scapulae should be assessed. The objective of the current study was to translate clinical methods of gait analysis and jump assessment to commercially available trunk-mounted accelerometers. The current study created a gait program to analyze and compile the gait data. Following completion of the gait program, the IMU (STATSports APEX) was investigated for validity against ankle accelerometers. Once the validity was determined, an application study evaluated the relevance of collecting gait data during a NCAA D1 Women's Soccer season. Similarly, the trunk-mounted accelerometer was validated against force plates to assess countermovement jump height. The final study assessed how both jump height and gait variables changed due to game-related decline in performance. This study provides evidence that trunk-mounted accelerometers are a valid tool for assessing temporal gait variables (ICCRight = 0.95 and ICCLeft = 0.96), CMJ height (ICCJH = 0.90) and flight time (ICCFT = 0.88). A longitudinal analysis of gait showed that StepL, StrideL, kleg, and postural variables changed regularly in pre-post comparisons of performance. Postural variables had more changes towards the end of the season. Root mean squares (RMS) of accelerations and angular velocities had the highest correlations to High Speed Running (HSR). Fractal step and stride length (StepLα and StrideLα) had the strongest correlation to Total Distance (Rstep = -0.29 and Rstride = -0.29), or Tot Dist. When comparing gait and CMJ analyses to detect game-related changes in performance, CMJ was more descriptive of fatigue. In a proof-of-concept study, pre-post changes in CMJ immediately before and after a game had a moderate negative correlation (R = -0.57) to Tot Dist. When the protocol changed to assess the differences between the days before and after the game, the correlation weakened to R = -0.27. Spatiotemporal and spring mass variables did not change, whereas postural variables appeared to improve. The current study has provided evidence that running gait could be used as an athlete monitoring technique, however more data needs to be collected to understand how running gait variables change with team-sports related fatigue.
Using Concept Maps as a Tool for Cross-Language Relevance Determination
Richardson, W. Ryan (Virginia Tech, 2007-06-06)
Concept maps, introduced by Novak, aid learners' understanding. I hypothesize that concept maps also can function as a summary of large documents, e.g., electronic theses and dissertations (ETDs). I have built a system that automatically generates concept maps from English-language ETDs in the computing field. The system also will provide Spanish translations of these concept maps for native Spanish speakers. Using machine translation techniques, my approach leads to concept maps that could allow researchers to discover pertinent dissertations in languages they cannot read, helping them to decide if they want a potentially relevant dissertation translated. I am using a state-of-the-art natural language processing system, called Relex, to extract noun phrases and noun-verb-noun relations from ETDs, and then produce concept maps automatically. I also have incorporated information from the table of contents of ETDs to create novel styles of concept maps. I have conducted five user studies, to evaluate user perceptions about these different map styles. I am using several methods to translate node and link text in concept maps from English to Spanish. Nodes labeled with single words from a given technical area can be translated using wordlists, but phrases in specific technical fields can be difficult to translate. Thus I have amassed a collection of about 580 Spanish-language ETDs from Scirus and two Mexican universities and I am using this corpus to mine phrase translations that I could not find otherwise. The usefulness of the automatically-generated and translated concept maps has been assessed in an experiment at Universidad de las Americas (UDLA) in Puebla, Mexico. This experiment demonstrated that concept maps can augment abstracts (translated using a standard machine translation package) in helping Spanish speaking users find ETDs of interest.

Browsing by Author "Tegarden, David P."

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