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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Determinants of packaged software discontinuance intentions: an empirical study of South African managers' perceptions

Formby, David Bruce 22 August 2014 (has links)
Thesis (M.Com. (Information Systems))--University of the Witwatersrand, Faculty of Commerce, Law and Management, School of Economic and Business Sciences, 2014. / Information systems discontinuance at the organisational level is an underrepresented research topic. However, it is an important problem in practice. The managerial decision to discontinue an existing information system by replacement, upgrade or abandonment requires extensive justification and evaluation. The timing of a system’s discontinuance is of strategic concern as the cost and impact of a packaged software application can be extensive. If the decision is made too early in the system’s life cycle, it can negatively affect the return on investment, but if the decision occurs too late, the system may become a liability to an organisation as it continues to consume resources in maintenance and support. A comprehensive framework is required that analyses the factors that determine discontinuance intentions of the decision makers within an organization. This study focuses on managerial perceptions of selected factors considered most important to discontinuance decisions. The study applies and extends the discontinuance framework proposed by Furneaux and Wade (2011) to develop a research model of the effects of these selected factors on organisational intentions to discontinue packaged software. Specifically, the research model hypothesizes the effects of ‘change’ forces that include the manager’s perceptions of system performance, system suitability and system supportability, as well as ‘inertia’ forces such as sunk cost, mimetic isomorphism and degree of the application’s integration into the enterprise architecture. The organisation’s ability to innovate, the age of the system and the presence of the initial sponsor are included as additional factors. To test the model, a survey methodology was employed to collect data from South African IT decision makers. The survey made use of a structured questionnaire instrument administered online. Useable data was collected from decision makers representing 103 organisations. Hypotheses were tested using regression and partial least squares structural modeling. Results showed that poor software performance, a lack of suitability and low levels of business and technical integration, were the strongest determinants of discontinuance intentions. The control effect of the software’s age relatively to the organisation’s portfolio of applications was proven to be significant in this research. This study has contributed by consolidating the effects of a number of factors drawn from the literature and developing an integrated framework of discontinuance. Results will help IT decision makers when considering a discontinuance decision by showing the relative effects of each factor and may be helpful to IT managers to determine the timing of the decision.
62

The effect of total knee replacement on measures of gait and stair ascent /

Mandeville, David Stewart, January 2006 (has links)
Thesis (Ph. D.)--University of Oregon, 2006. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 102-109). Also available for download via the World Wide Web; free to University of Oregon users.
63

An investigation of the biomechanical factors influencing knee joint function following total knee replacement

Byrne, Jeannette January 2009 (has links)
Knee replacement surgery is often performed in cases where the pain due to knee osteoarthritis can no longer be effectively controlled by conservative measures. The surgery—which replaces the articular surfaces of the tibia, femur and sometimes the patella with a mix of metal and polyethylene—is one of the most commonly performed lower limb surgeries. Despite patient reports of reduced pain and increased participation in activities of daily living, knee function following total knee arthroplasty (TKA) does not return to normal. Reductions in both passive and active knee range of motion, alterations in magnitude and timing of muscle activity, and changes in knee joint kinetics have all been reported. Comparatively little is known about why knee function is altered following TKA. In an attempt to address this gap in the literature, this thesis was designed to examine the biomechanical factors thought to contribute to reduced knee extensor moments following TKA. In particular, the contribution of alterations in passive knee moments, muscle moment arm lengths, and muscle activation magnitude and timing were examined in detail to determine which factors contributed to reduced knee extensor moment following TKA. To accomplish this goal, two groups--6 healthy controls and 6 individuals who were at least one year post-TKA—were examined in four different studies. The initial study of this thesis, a comprehensive examination of patients and controls during gait and stepping onto a raised surface, had two purposes. This moment data was needed to clearly define the knee moment deficits that existed in the patient – the remainder of the thesis focused on determining why these specific deficits existed. A secondary aim of this first study was to allow for the assessment of muscle activation patterns in this population during weight bearing tasks. Results of study one confirmed the existence of knee extensor moment deficits in the TKA group and also demonstrated that patients exhibited increased gastrocnemius EMG, prolonged stance phase activation of biceps femoris and reduced knee flexion during the loading phase of stance. Analysis of results across the two tasks suggested that reduced knee moments in members of the TKA group may be related to changes in gastrocnemi activation, however, differences in knee joint kinematics between patients and controls made it difficult to draw this conclusion. Study number two was designed to further probe the muscle activation strategies adopted by members of the TKA group. In order to avoid complications involved when comparing muscle activation patterns between groups using different kinematic strategies, seated knee extension was examined. This task was chosen as it challenged the knee musculature while at the same time restricting both groups of participants to use the same knee joint kinematics. The results of this analysis revealed that, while EMG magnitude for quadriceps and hamstrings were similar for both groups, patients exhibited increased amplitude of EMG in both the medial and lateral gastrocnemi. While the first two studies of this thesis focused on the active knee joint moment, in the third study the force required to passively move the knee from a flexed to an extended position was measured and used to estimate the passive moment of the knee joint. This study was based on the rational that if the passive knee moment was altered following TKA it could potentially affect the net knee joint moment. The comparison of patient and control results showed that, while small changes in passive moment were evident in patients, these differences were not large enough to account for changes in the knee extensor moment. The goal of the final thesis study was to examine moment arms of the knee musculature in an attempt to determine if TKA resulted in changes to this variable. However, various methodological issues arose in the course of completing this study. As a result, limited data were produced that sufficiently addressed the question posed. Despite the problems that arose, important issues regarding in vivo moment arm determination were realized and are included for discussion in this thesis. Together, the four studies provided a unique opportunity to observe knee function over a range of activities. The following conclusions were reached. • Changes in passive knee moment did not seem to contribute to reductions in knee extensor moment observed following TKA. • Quadriceps and hamstring muscle function, as evidenced by EMG recording during the seated knee extension task, appeared intact following TKA, suggesting that alteration in the function of these muscles were not directly responsible for reductions in knee extensor moments. • Changes in medial and lateral gastrocnemi activation were observed during knee extension and weight-bearing tasks. These changes may account for reduced knee extensor moment, particularly during the step-up task. • Knee extensor moment reductions during gait appear to be related to the reduced knee flexion exhibited by patients during the stance phase of gait . It was hypothesized that these changes in knee kinematics were directly linked to the increased activation of the gastrocnemi during gait. Although low subject numbers limited the generalizability of the results these conclusions will serve to guide future research in this area and ultimately help improve function and quality of life in this patient population.
64

An investigation of the biomechanical factors influencing knee joint function following total knee replacement

Byrne, Jeannette January 2009 (has links)
Knee replacement surgery is often performed in cases where the pain due to knee osteoarthritis can no longer be effectively controlled by conservative measures. The surgery—which replaces the articular surfaces of the tibia, femur and sometimes the patella with a mix of metal and polyethylene—is one of the most commonly performed lower limb surgeries. Despite patient reports of reduced pain and increased participation in activities of daily living, knee function following total knee arthroplasty (TKA) does not return to normal. Reductions in both passive and active knee range of motion, alterations in magnitude and timing of muscle activity, and changes in knee joint kinetics have all been reported. Comparatively little is known about why knee function is altered following TKA. In an attempt to address this gap in the literature, this thesis was designed to examine the biomechanical factors thought to contribute to reduced knee extensor moments following TKA. In particular, the contribution of alterations in passive knee moments, muscle moment arm lengths, and muscle activation magnitude and timing were examined in detail to determine which factors contributed to reduced knee extensor moment following TKA. To accomplish this goal, two groups--6 healthy controls and 6 individuals who were at least one year post-TKA—were examined in four different studies. The initial study of this thesis, a comprehensive examination of patients and controls during gait and stepping onto a raised surface, had two purposes. This moment data was needed to clearly define the knee moment deficits that existed in the patient – the remainder of the thesis focused on determining why these specific deficits existed. A secondary aim of this first study was to allow for the assessment of muscle activation patterns in this population during weight bearing tasks. Results of study one confirmed the existence of knee extensor moment deficits in the TKA group and also demonstrated that patients exhibited increased gastrocnemius EMG, prolonged stance phase activation of biceps femoris and reduced knee flexion during the loading phase of stance. Analysis of results across the two tasks suggested that reduced knee moments in members of the TKA group may be related to changes in gastrocnemi activation, however, differences in knee joint kinematics between patients and controls made it difficult to draw this conclusion. Study number two was designed to further probe the muscle activation strategies adopted by members of the TKA group. In order to avoid complications involved when comparing muscle activation patterns between groups using different kinematic strategies, seated knee extension was examined. This task was chosen as it challenged the knee musculature while at the same time restricting both groups of participants to use the same knee joint kinematics. The results of this analysis revealed that, while EMG magnitude for quadriceps and hamstrings were similar for both groups, patients exhibited increased amplitude of EMG in both the medial and lateral gastrocnemi. While the first two studies of this thesis focused on the active knee joint moment, in the third study the force required to passively move the knee from a flexed to an extended position was measured and used to estimate the passive moment of the knee joint. This study was based on the rational that if the passive knee moment was altered following TKA it could potentially affect the net knee joint moment. The comparison of patient and control results showed that, while small changes in passive moment were evident in patients, these differences were not large enough to account for changes in the knee extensor moment. The goal of the final thesis study was to examine moment arms of the knee musculature in an attempt to determine if TKA resulted in changes to this variable. However, various methodological issues arose in the course of completing this study. As a result, limited data were produced that sufficiently addressed the question posed. Despite the problems that arose, important issues regarding in vivo moment arm determination were realized and are included for discussion in this thesis. Together, the four studies provided a unique opportunity to observe knee function over a range of activities. The following conclusions were reached. • Changes in passive knee moment did not seem to contribute to reductions in knee extensor moment observed following TKA. • Quadriceps and hamstring muscle function, as evidenced by EMG recording during the seated knee extension task, appeared intact following TKA, suggesting that alteration in the function of these muscles were not directly responsible for reductions in knee extensor moments. • Changes in medial and lateral gastrocnemi activation were observed during knee extension and weight-bearing tasks. These changes may account for reduced knee extensor moment, particularly during the step-up task. • Knee extensor moment reductions during gait appear to be related to the reduced knee flexion exhibited by patients during the stance phase of gait . It was hypothesized that these changes in knee kinematics were directly linked to the increased activation of the gastrocnemi during gait. Although low subject numbers limited the generalizability of the results these conclusions will serve to guide future research in this area and ultimately help improve function and quality of life in this patient population.
65

Mandatory Restatements, Family Involvement and Replacement Decisions for Related Parties of Financial Statements

Wei, Jo-Ting 19 August 2010 (has links)
Mandatory restatements are unique in the nature whereas they are often ignored in restatement literature examining restating firms¡¦ replacement decisions. Furthermore, family studies little examine the role family involvement plays in determining financial reporting quality and firms¡¦ replacement decisions. This paper is motivated to investigate the impact of mandatory restatements and the restatement severity to related parties of financial statements. Particularly, this paper also concerns on the moderating effect of family involvement (family shareholding and family directorships) in the above association. The findings indicate that mandatory restating firms would replace top management, financial executives, firm auditors and supervisors. Firms with higher mandatory restatement severity have more frequent turnover of firm auditors, supervisors and internal auditors. Besides, the findings show that family involvement is an essential moderating factor in the relationship between mandatory restatement and firms¡¦ replacement decisions. The evidence shows that family shareholding has limited motivating effects for family members to be in favor of the replacement of related parties of financial statements involving in material financial reporting failure. However, family directorships enhance family members¡¦ entrenchment in influencing the firms¡¦ replacement decisions so as to strengthen family control. Some evidence indicates that mandatory restating firms would still replace family CEO with family CEO, which further supports the possibility that family members limit managerial positions to capture control of the firms. Overall, the evidence provides a warning sign to Taiwanese security regulators that there¡¦s a necessary to emphasize the punishment mechanisms for those who are responsible for accounting scandals, strengthen managerial turnover disclosure about their family status and educate individual investors the value of turnover disclosure.
66

Gait performance for individuals after total knee arthroplasty a longitudinal analysis /

Yoshida, Yuri. January 2009 (has links)
Thesis (Ph.D.)--University of Delaware, 2009. / Principal faculty advisor: Lynn Snyder-Mackler, Dept. of Physical Therapy. Includes bibliographical references.
67

Replacement decisions of production assets : an optimization approach /

Mak, Sek-man, Leo. January 1986 (has links)
Thesis (M.B.A.)--University of Hong Kong, 1987.
68

Field Measurements of Surface Displacements from Pipe Bursting

McLeod, Heather 15 January 2009 (has links)
Two field studies of surface displacements during pipe bursting were conducted. The first field study consisted of a controlled experiment in clay soil. Three vitrified clay pipelines, each at a different burial depth, were up-sized to high density polyethylene (HDPE) pipes using static pipe bursting techniques. Surface displacements during the pipe bursting process were monitored using digital imaging techniques as well as surveying. It was found that ground displacements were largest in the vertical direction, such that the maximum vertical displacements measured during pipe bursting ranged from 71.8 ± 7.5 mm at a depth of cover of 0.6 m and 11.2 ± 1.2 mm at a depth of cover of 1.5 m. Transverse displacements generated during pipe bursting were found to correspond to tension cracking of the ground surface above the pipe. The second field study examined pipe bursting installations which took place at the Royal Canadian Mounted Police College campus in Ottawa, Ontario. During this study, five pipe bursting installations were monitored. Each installation varied in terms of the surface and subsurface conditions, host pipe size and material, replacement pipe size, and depth of cover. The pattern of displacements distributed in all three directions was consistent with the results from the controlled study. However, greater variability in results was found during the Ottawa project. Vertical displacements were found to range from 0.6 ± 0.1 mm to 11.3 ± 0.2 mm for pipe bursts carried out to the same up-size dimension, at approximately the same depth of cover, surrounded by similar surface and subsurface conditions. In general, pipe bursting in clayey soils with an unpaved surface resulted in larger displacements having a narrower distribution over the ground surface than the paved installations. Additionally, increased variability in results occurred under real construction conditions due to inherent variability in subsurface and host pipe conditions. / Thesis (Master, Civil Engineering) -- Queen's University, 2008-12-23 12:52:08.301
69

Mechanical factors in the management of osteoarthritis of the knee

Donell, Simon Thomas January 2001 (has links)
No description available.
70

The chemical vapour deposition of diamond on surgically implantable stainless steel

Morrison, Neil Alexander January 1997 (has links)
No description available.

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