Maintenance can be performed according to one of two strategies, failure based or condition based. In most cases, where large and expensive assets such as wind turbines are operated on a continuous basis, condition based maintenance is preferred. However, condition based maintenance relies on the continuous and accurate gathering of condition-information of the particular machine and its various components. This dissertation reports the experimental and numerical work performed as part of the development of an experimental facility that will allow the development of condition monitoring techniques for wind turbines. This work is focussed on the torsional dynamics of a wind turbine setup. A physical setup, consisting of a 1.6 m diameter turbine, a 1:1. ̇ speed-multiplication gearbox, and a 24 Volt direct current generator is built. All of it is mounted within an open-return wind tunnel, which is also designed and built as part of this work. The following two cost-effective experimental techniques are used to measure the torsional natural frequencies: a shaft encoder tachometer from which instantaneous rotational frequency is obtained, and power signal analysis, where the generated voltage is recorded and analysed. It is shown how an algorithm developed by Diamond et al. (2016) is used for the shaft encoder geometry compensation. Frequency spectra based on Fourier transforms and short time Fourier transforms are used to identify harmonic frequencies. Both measurement techniques proves useful to identify not only natural frequencies of torsional vibration, but also various characteristic frequencies of the drivetrain such as shaft rotation, blade pass, gear mesh and generator armature. It is found that power signal analysis is more useful to identify the characteristic frequencies. Torsional dynamics of the drivetrain and its components are also investigated with the following two numerical methods: an eight-degree-of-freedom torsional Lumped Mass Model (LMM), and a three-dimensional Finite Element Model (FEM). Torsional mode shapes and frequencies are calculated with both methods and a good agreement is found in the lower four modes. Numerical results are then compared with the experimental results, where there is also good agreement in the lower four modes. Model updating is performed on the FEM and by changing the torsional stiffness of the flexible couplings, the difference between measured and calculated natural frequencies are reduced to less than 6 %. It is concluded that future models should address lateral vibration of the drivetrain and the support structure. From this study the following is contributed to the wind turbine condition monitoring field: considerations for the design and a working example of an experimental facility for investigating torsional dynamics, illustration of two measurement techniques, and two types of validated numerical models. / Dissertation (MEng)--University of Pretoria, 2018. / Mechanical and Aeronautical Engineering / MEng / Unrestricted

Failures in competitive intelligence are widely reported but are seldom studied through an information behaviour lens or specifically attributed to information activities and factors influencing information behaviour. This dissertation addresses this gap. The research question was: How are competitive intelligence failures attributed to information behaviour? Sub-questions included:  How is lack of understanding of competitive intelligence contributing to competitive intelligence failure?  How are the identification and expression of intelligence needs contributing to competitive intelligence failures?  How are difficulties experienced in data collection contributing to competitive intelligence failures?  How are information sharing and specifically feedback mechanisms contributing to competitive intelligence failures?  How are other information activities (apart from the recognition and expression of information needs, data collection and information sharing) o contributing to competitive intelligence failures? o preventing competitive intelligence failures? Eclectic versions of the competitive intelligence life cycle (mostly based on the Bose (2008) and Botha and Boon (2008) interpretations) and information-seeking/information behaviour model (mostly based on the Wilson (1981) and Leckie, Pettigrew and Sylvain (1996) models) served as conceptual frameworks for data collection and analysis. The study followed a survey method using semi-structured individual interviews with 15 competitive intelligence professionals, educators and trainers. They were recruited through purposive and snowball sampling. A profile questionnaire of limited scope collected descriptive quantitative data on educational level, professional position, formal training in competitive intelligence and description of job titles. Semi-structured individual interviews were conducted through face-to-face, SKYPE, telephonic call and face-time call interviews. Data was collected from 31/08/2016 to 30/01/2017. Thematic analysis was applied to the qualitative data, identifying core themes and sub-themes for each sub-problem. Findings are used to populate the two frameworks: competitive intelligence cycle and information behaviour, before suggesting a framework with elements from both to guide future studies on competitive intelligence failures from an information behaviour perspective. Suggestions for theories to consider in future research, competitive intelligence practices, and further research are included. / Dissertation (MIS)--University of Pretoria, 2017. / National Research Foundation (NRF) / Information Science / MIS / Unrestricted

This archival study sought to investigate the construct validity of the Toronto Alexithymia Scale (TAS-20) when used with an inpatient clinical population. The TAS-20 is a self-report instrument that measures alexithymia, a psychological construct that encompasses 4 main cognitive traits: difficulty identifying feelings, difficulty describing feelings to others, externally oriented thinking, and a limited imaginal capacity. Seven separate studies were employed: Study 1 explored internal consistency; Study 2 explored factor structure; Study 3 explored criterion-based predictive validity; Study 4 explored convergent validity; Study 5 explored discriminant validity; and Studies 6 and 7 explored the relationship between TAS-20 scores and Axis I and Axis II diagnoses. The participants were 169 inpatients at a state mental hospital in the Southeast. Participants were administered the TAS-20 while participating in the hospital's Dialectical Behavior Therapy (DBT) program between 2002 and 2011. Study results revealed a reliability coefficient of .793 and a two factor solution. However, subsequent analyses revealed that removal of the reverse score items increased internal consistency and that the best solution was a 1 factor solution with the TAS-20 reverse scored items removed. TAS-20 scores were found to be weakly predictive of both self-harm and acting-out behavioral incidents. A significant, but weak, positive correlation was found between TAS-20 scores and a measure of trauma. There was no significant relationship found between TAS-20 scores and a measure of verbal IQ. No relationship was found between TAS-20 scores and either Axis I or II diagnoses. Overall, the research findings provided weak support for the construct validity of the TAS-20 when used with a severely mentally ill inpatient population. Due to its questionable construct validity, the TAS-20 should be used with inpatient clinical populations in conjunction with other alexithymia measures, clinical interviews and behavioral observations. Because of the TAS-20's cost effectiveness and ease of use, further refinement of the items of the TAS-20 is recommended along with further research on the construct validity of a modified instrument. / A Dissertation submitted to the Department of Educational Psychology and Learning Systems in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Spring Semester, 2012. / March 15, 2012. / alexithymia, "construct validity", "inpatient clinical population", reliability, TAS-20 / Includes bibliographical references. / Deborah Ebener, Professor Directing Dissertation; Jeanette Taylor, University Representative; Gary Peterson, Committee Member; Jim Sampson, Committee Member.

Shape analysis of curves and surfaces is a very important tool in many applications ranging from computer vision to bioinformatics and medical imaging. There are many difficulties when analyzing shapes of parameterized curves and surfaces. Firstly, it is important to develop representations and metrics such that the analysis is invariant to parameterization in addition to the standard transformations (rigid motion and scaling). Furthermore, under the chosen representations and metrics, the analysis must be performed on infinite-dimensional and sometimes non-linear spaces, which poses an additional difficulty. In this work, we develop and apply methods which address these issues. We begin by defining a framework for shape analysis of parameterized open curves and extend these ideas to shape analysis of surfaces. We utilize the presented frameworks in various classification experiments spanning multiple application areas. In the case of curves, we consider the problem of clustering DT-MRI brain fibers, classification of protein backbones, modeling and segmentation of signatures and statistical analysis of biosignals. In the case of surfaces, we perform disease classification using 3D anatomical structures in the brain, classification of handwritten digits by viewing images as quadrilateral surfaces, and finally classification of cropped facial surfaces. We provide two additional extensions of the general shape analysis frameworks that are the focus of this dissertation. The first one considers shape analysis of marked spherical surfaces where in addition to the surface information we are given a set of manually or automatically generated landmarks. This requires additional constraints on the definition of the re-parameterization group and is applicable in many domains, especially medical imaging and graphics. Second, we consider reflection symmetry analysis of planar closed curves and spherical surfaces. Here, we also provide an example of disease detection based on brain asymmetry measures. We close with a brief summary and a discussion of open problems, which we plan on exploring in the future. / A Dissertation submitted to the Department of Statistics in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Summer Semester, 2012. / April 27, 2012. / curves, geodesics, medical imaging, statistical shape analysis, surfaces / Includes bibliographical references. / Anuj Srivastava, Professor Directing Thesis; Eric Klassen, University Representative; Wei Wu, Committee Member; Fred Huffer, Committee Member; Ian Dryden, Committee Member.

Criminological research has often overlooked an important segment of offenders' lives - incarceration. Furthermore, the existing research on inmate behavior has focused primarily on male inmates. This dissertation adds to corrections literature by using a sample of female inmates to examine relationships between personality disorders and prison adjustment. The results of the analyses indicate that personality disorders are widespread among female inmates and are somewhat associated with adjustment. Certain Cluster B personality disorders - antisocial, histrionic, and narcissistic - were associated with decreased adjustment. Dependent personality disorder, on the other hand, was associated with increased adjustment, since these inmates self-reported less misconduct than other inmates did. The remaining personality disorders did not have any significant relationships with the measures of adjustment. Other factors, such as age, sentence length, time served, and security classification, had a more consistent association with adjustment than personality disorders. When female inmates with personality disorders were examined separately, unique patterns of adjustment were found. Age was associated with an increased number of infractions that the inmate was reported by prison staff to have committed and increased self-reported misconduct. Age, however, was not significantly related to violent infractions. For female inmates with personality disorders, race was not significantly related to adjustment. On the other hand, being a parent was associated with an increased number of violent infractions reported. Limitations to this dissertation and policy implications for corrections and criminology are discussed. / A Dissertation submitted to the College of Criminology and Criminal Justice in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Fall Semester, 2011. / October 3, 2011. / Disciplinary Infractions, Inmates, Mental Illness, Personality Disorders, Prison Adjustment / Includes bibliographical references. / Kevin Beaver, Professor Directing Dissertation; Joyce Carbonell, University Representative; Daniel Mears, Committee Member.

Universities and colleges in the United States are vital communities, teeming with people and vast resources. Because of such factors as class schedules, on-going research, tight academic calendars and highly transient populations, these communities function with diverse operations that need a constant degree of normality for maximum effectiveness. Due to the specialized nature of higher education institutions, universities and colleges are vulnerable to a wide range of situations capable of upsetting normal day-to-day operations. For any university or college, the safe operation of campus is essential to the goals of the institution, the quality of the environment, and even its survival. Among higher education institutions, the issue of safety is a broad and encompassing concept but often with no clear lines of responsibility. In contrast to industries, which have special units or groups of people to plan and deal with disruptions or emergency situations, higher education institutions often overlook or even ignore safety concerns. Among most industries, especially those involving work with volatile chemicals or other substances as well as dangerous activities, safety is an essential element of sound management. To address the safe operation of a campus, every higher education institution in the United States has, in one form or another, has an environmental health and safety (EH&S) program. The main principle of an EH&S program is to support and advance the teaching and research activities of the institution through the promotion of a safe and healthy campus, by providing and coordinating services that minimize the risk of occupational illness, injury or environmental contamination. Given the diversity that characterizes the array of colleges and universities in the United States in the 21st century, it is important to know the structure of EH&S programs in higher education institutions and how they are implemented. However, few, if any, studies have been conducted to examine what EH&S programs are comprised of, what role they play in higher education institutions, how they are organized and structured, how they are funded and staffed, and what effect they have on the risk of accidents or the fiscal impact to institutions. This study have determined that for research institutions, the staff and funding of EH&S programs have significant impacts on the safe operation of the institution. In particular, EH&S staff number has a significant impact on the number of reported injuries and illnesses and the number of lost workdays. The study also found that there are two types of organizational structures for EH&S programs: a centralized EH&S program, where all the components are within a dedicated EH&S program; and a fragmented structure where the components are disjointed from one another and would report to the institution's higher administration directly and separately. However, the study found that the EH&S organization structures reporting schemes are not significant in ensuring the safe operation of the institution. Furthermore, the study found that EH&S program expenditures significantly affect the safety goal. / A Dissertation submitted to the Department of Educational Leadership and Policy Studies in partial fulfillment of the requirements for the degree of Doctor of Education. / Fall Semester, 2011. / June 27, 2011. / College health and safety, Colleges and universities EH&S program, EH&S, EH&S program, Environmental health and safety, Safety program at research colleges and universities / Includes bibliographical references. / Robert A. Schwartz, Professor Directing Dissertation; Frances Berry, University Representative; Shouping Hu, Committee Member; Kathy Guthrie, Committee Member.

The purpose of this study was to explore the nature of students' mapping and discourse behaviors while constructing causal maps to articulate their understanding of a complex, ill-structured problem. In this study, six graduate-level students were assigned to one of three pair groups, and each pair used the causal mapping software program, jMAP, to collaboratively construct causal maps as they discussed and worked hand-in-hand with a student peer to diagnose an instructional design problem. Sequential analysis was used to analyze video recordings of each pair's computer desktop to identify typical processes and patterns of mapping and discourse behaviors used by the students. Most of all, sequential analysis was used to compare and identify differences in the sequential patterns and processes of mapping and discourse behaviors between student pairs - differences that might help to explain observed differences in the accuracy of the maps produced by the student pairs. Overall, the findings in this study revealed different behavioral patterns in the map construction process between the groups - differences that provided plausible explanations as to why some groups produced more accurate maps than others. Group 1 followed a four-step linear process of executing the major map drawing behaviors of node positioning, inserting causal links, changing link attributes, and inserting comments on a link. The pattern exhibited by Group 1's discourse revealed how one dominant student's explanations presented just prior to positioning a node and inserting links were intended to simply to announce (as opposed to initiate discussion) the next mapping action the student was about to perform on the group's causal map. As a result, Group 1 produced the least accurate map among the three groups. In contrast, Group 2 used a three-step linear but iterative process of positioning nodes, adding links, and specifying link attributes while working progressively backwards from nodes that had the most direct and/or immediate effect on the outcome variable to those that had the least direct/immediate effect. Group 2 engaged in collaborative discussions (primarily initiated by explanations presented by the more knowledgeable student) to decide where to place and link the next node, a process which produced the most accurate map among the three groups. Group 3, which produced the second most accurate map among the three groups, followed a stepwise process in which the students shared equal responsibility in positioning all or most of the nodes first (with each node positioning preceded and/or followed immediately with collaborative discourse) before placing links between the nodes. Group 3 also exhibited a pattern which suggests that nodes and links were placed to create a shared visual artifact that could then be used to explain and re-evaluate the most recent action performed on the map. The behavioral patterns and their association with map accuracy suggest two procedures to incorporate into existing causal mapping guidelines. First, encourage students to use an iterative and systematic mapping approach while working progressively backwards from the final outcome to the mediating and root causes. Second, prompt students to engage in collaborative and interrogative exchanges to share ideas and make meaningful contributions to the causal reasoning and map construction process. The main implication of this study is that these and other established causal mapping processes can now be operationally measured and tested, and most all, formalized, standardized, and built into the causal mapping software/interface to reduce individual differences in causal mapping skills. In doing so, causal mapping software may one day be used as a tool for conducting large-scale formative and summative assessments of students' understanding of complex systems. Furthermore, the methods and findings presented in this study provide ideas for future research on how to improve the process-oriented approach to studying the instructional uses of causal maps. / A Dissertation submitted to the Department of Educational Psychology and Learning Systems in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Spring Semester, 2012. / February 16, 2012. / Case Diagnosis, Causal Map, Causal Reasoning, Problem Solving / Includes bibliographical references. / Allan Jeong, Professor Directing Dissertation; Paul Marty, University Representative; Valerie Shute, Committee Member; Vanessa Dennen, Committee Member.

Recent research on structural priming has found that cumulative priming effects established in one experimental session can persist for a week and affect a participant's subsequent linguistic productions (e.g., Kaschak, Kutta, & Schatschneider, 2011). Furthermore, the results of Kaschak, Kutta, & Coyle (under review) indicated that the persistence of the priming effect over the course of a week was dependent upon the participant performing the same language production task that they had a week before. This provided evidence that the long-term cumulative structural priming effect operates in a context-specific manner, however it is unclear exactly what types of memory contribute to these long-term priming effects. The persistence of this long-term cumulative structural priming effect seems to be primarily due to the participant's implicit learning of the biased syntactic construction and the procedural learning that occurred in the biasing phase. If the priming effect is primarily due to implicit learning, then it should be insensitive to changes in the extrinsic context and follow the pattern of results found in McKone and French (2001). The results of the present study indicate that the long-term persistence of the priming effect was insensitive to any changes in the extrinsic context. This study provides strong evidence that long-term structural priming effects should be attributed to an implicit learning mechanism within the language production system. Implications for the role of memory in a structural priming task and prospective research are discussed. / A Thesis submitted to the Department of Psychology in partial fulfillment of the requirements for the degree of Master of Science. / Fall Semester, 2011. / October 24, 2011. / Context, Implicit Learning, Structural Priming / Includes bibliographical references. / Michael Kaschak, Professor Directing Thesis; Colleen Kelley, Committee Member; Carol Connor, Committee Member.

This study was conducted to examine the: (a) heterogeneity and prevalence of the language and literacy profiles among first grade students, (b) predictors that optimize the classification of language and literacy profiles, (c) latent transitions comprising students assigned to the mover latent class and students assigned to the stayer latent class across fall and spring and the prevalence of these latent classes, and (d) predictors that significantly characterized the transition of class membership. Mixture modeling was used to address these aims. A sample of 521 first-grade students was drawn from seven schools. As hypothesized using the Simple View of Reading as a theoretical framework, five language and literacy profiles were identified. These were students with: a) the weakest performance on average in literacy but slightly higher language skills (13%), b) weak performance in both language and literacy (31%), c) average performance in language and literacy (27%), d) good (above average) performance on language and literacy (21%), and e) the strongest performance in language and literacy (8%). Unique predictors of class membership differentiation for all groups were phonological awareness, teacher judgment on academic performance, and socioeconomic status. Measures of letter sound fluency and oral language uniquely predicted group differentiation for some groups. There were proportionately more students who were assigned to the mover latent class (higher overall means) than students who were assigned to the stayer latent class (lower overall means). The mover latent class had some probability of moving classes while the stayer latent class had zero probability of moving classes. The mover latent class and stayer latent class were uniquely differentiated by letter sound fluency, phonological awareness, socioeconomic status, and participation in tiered conditions. The policy and practical implications of these results are discussed. / A Dissertation submitted to the School of Teacher Education in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Summer Semester, 2012. / June 25, 2012. / CLASSIFICATION, LANGUAGE AND LITERACY PROFILES, MIXTURE MODELING, READING DISABILITIES, RESPONSE TO INTERVENTION, SIMPLE VIEW OF READING / Includes bibliographical references. / Barbara R. Foorman, Professor Co-Directing Dissertation; Stephanie Dent Al Otaiba, Professor Co-Directing Dissertation; Richard K. Wagner, University Representative; Young-Suk Kim, Committee Member; Jeannie Wanzek, Committee Member.

This dissertation has grown out of a simple observation. I happened to be reading selections from Bishop Joseph Butler's sermons and his dissertation On the Nature of Virtue around the same time that I was reading Jane Austen's Mansfield Park,, and was struck by the similarities I perceived between the two works. The more I read in each, the stronger was my sense of a general resemblance between Butler's and Austen's interests and convictions regarding the moral life of human beings. Personal interest alone would have been enough to encourage me to investigate the nuances and finer points of the two authors' shared ethic and moral psychology, but I am additionally persuaded of the value of such a project to both Austen scholars and those philosophers who are concerned with sustaining and nurturing a mutually beneficial dialogue between the works and disciplines of literature and philosophy. At its broadest, my aim here is to provide textual support from both authors for my claim that Mansfield Park expresses and endorses views about the moral nature of human beings and about the causes and effects of virtue and vice that strongly coincide with Butler's. Essentially, my argument rests on two observations. The first is that of the number and prominence of shared concepts between the two authors including: the nature and importance of moral judgment to moral behavior and the corresponding unreliability of reference to moral rules for producing moral behavior, the idea that there is a natural and beneficial hierarchical organization of motivational principles within an individual agent's psychology, and an appreciation of the dangerous connection between self-deceit and vice. My second observation is that the plot of Mansfield Park bears out these commitments beyond simply affirming them in particular characters whom Austen wants her reader to accept as moral role models or exemplars. That is, while it is true that Fanny Price, as an individual, demonstrates the value of judgment and critical reflection, and of successful moral action without reference to strict moral principles or rules, what seems to me to be more important is the fact that controversial elements of the plot of the novel seem to be expressions of Butler's views as well. Austen is worried about Edmund Bertram's infatuation with Mary Crawford because she, like Butler, is worried about the reinforcing effect of self-deceit on establishing morally problematic action a habit. This causes her to be anxious about the morality of her characters' efforts to perform the play "Lover's Vows". It seems to me that when we properly appreciate the moral thought underlying this worry, Austen's much-maligned `priggishness' regarding the play becomes more understandable and less alien than it first appears. In other words, when we have Butler's Sermons and the Dissertation Of the Nature of Virtue at hand when we read Mansfield Park we are less likely to be perplexed by events in the novel and the narrator's perspective on them for the simple reason that we have better access to the moral psychology Austen was working with. / A Dissertation submitted to the Department of Philosophy in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Spring Semester, 2012. / March 14, 2012. / Bishop Butler, Jane Austen / Includes bibliographical references. / David McNaughton, Professor Directing Dissertation; Eric Walker, University Representative; John Roberts, Committee Member; Piers Rawling, Committee Member.