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Mosaic Arthroplasty is a well-accepted surgical approach to treating focal cartilage defects of the knee. However, the task of creating the mosaic of osteochondral grafts that optimally restores the cartilage surface is technically demanding. Conventional techniques require the surgeon to reconstruct a complex, three-dimensional surface by eye and experience only. There is evidence that this type of procedure is sensitive to technique: grafts that are transplanted proud of the native cartilage surface tend to show evidence of cartilage fissuring and fibrillation prematurely. Two computer-assisted techniques (navigation by optical tracking and guidance by patient-specific templates) were investigated to determine whether they would have a beneficial effect on surgical execution, and whether any differences in execution had any correlation to surgical outcome. The experimental work can be broken into two parts: an in vitro study that compared the accuracy of execution of an optically navigated group versus a template guided group, and an in vivo animal trial that compared both computer assisted techniques to the conventional, non-assisted approach. The results of the pilot study indicated that, while there were higher errors in the individual measures of position, orientation, and plug depth in the optically navigated group, there was no significant difference in the overall fidelity of the geometric surface produced between the two groups. The results of the animal trial indicated that both computer assisted techniques produced morphological results that were superior to the conventional technique. The two computer-assisted techniques also showed a significantly better treatment effect as seen by their higher histological scoring. Furthermore, a significant linear correlation was found between morphological results and histological score. Overall, the experiments demonstrated that surgeons and patients could potentially benefit from the use of computer-assisted techniques in the short term. Further work is required to prove long-term beneficial effect. / Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2012-11-02 20:50:33.957

This dissertation presents a thesis on the use of additive manufacturing in the development and evaluation of a computer-assisted system for wrist-fracture repair. The work developed tools for performing navigated wrist surgery, developed methods for evaluating surgical performance, and provided novel experience with model-based surgical evaluation. Patient-derived bone models, fabricated using additive manufacturing, were proposed as an alternative to cadaver specimens for testing and validating the new surgical system. The accuracy of fabricating these models from computed-tomography imaging was investigated using laser scanning and was found to be reproducible to within half a millimeter. Three generations of a surgical system for navigated wrist-fracture repair were developed and evaluated using a wrist model that was produced by additive manufacturing. Compared to cadaver specimens, the model was less expensive and performed equally well under simulated surgical conditions. The model-based evaluation permitted larger study sizes that increased the statistical power of the experimental results. Criteria for surgical performance included surgical and technical measurement of screw placement. The navigation system was superior in optimizing screw placement compared to conventional surgical methods. Navigation also reduced the risk of radiation exposure and clinical complications of wrist-fracture repair. Surgical tools, including a drill guide and wrist-stabilization device were developed with the use of additive manufacturing. Prototype devices could be quickly and economically fabricated for testing under realistic conditions. A system for performing navigated wrist fracture repair was successfully developed through the use of additive-manufacturing prototyping and evaluation. Additive manufacturing was integral to the successful evaluation of the system's improvement in performance. / Thesis (Ph.D, Mechanical and Materials Engineering) -- Queen's University, 2012-12-19 11:40:46.269

Using Carl Glickman's model, the purpose of this study was to examine the effect computer assisted instruction had in teaching Developmental Supervision. The research expectancies were to yield improved supervisory behavior and conceptual understandings of Developmental Supervision, in the areas of style flexibility and style effectiveness. A synopsis of pertinent literature in these areas suggests that the supervisory role of school administrators need style flexibility, .style effectiveness, and the use of technology, computer assisted instruction, as a major component in educational improvement. Thirty-two (N = 32) administrators from a large metropolitan public school system in the south were randomly selected for participation in this study. The subjects were randomly assigned to the control group and experimental group, 16 and 16, respectively. The treatment utilized a three-session workshop format for the experimental group and no treatment was administered to the control group. Using a pre-test post-test design, both groups were administered the pre-test, Leadership Behavior Analysis II, during the first session. During the second session, the control group was given a placebo. The administration of the treatment was conducted by computer assisted instruction for the experimental group only. The disk began with the Supervisory Beliefs Inventory, individually, to ascertain their actual supervisory style; collaborative, directive or nondirective. The second section of the disk addressed training in supervisory style, teacher maturity, and the methodology needed to aid teachers to developmentally improve. The third session was in two parts: The beginning session for the experimental group was a discussion of the Developmental Supervision concepts and the control group experienced another placebo. The final component of the training was the administration of the post-test, Leadership Behavior Analysis II, to all subjects simultaneously. A t-test for independent and dependent samples was used to ascertain the difference between means in the sixteen experimental subjects and the control subjects. The Pearson Product Moment Correlation was administered to the data to determine the strength of the relationships in the control group and experimental group or pre-test and post-test results, respectively. The pre- and post-tests findings on the Pearson Product Moment showed a weak relationship in the experimental and control group. The pre- and post-tests findings, as were determined through the use of a t-tests for dependent and independent samples suggests that the use of computer assisted instruction to teach the key concepts of Developmental Supervision did not have a significant impact on the style effectiveness and style flexibility of supervisors in the school environment. In conclusion, the use of computer assisted instruction to teach key concepts of Development Supervision had no significant impact on the style flexibility and style effectiveness of the experiment group as compared with the control group.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

The purpose of this research was to develop a collaborative e-Learning framework using summarised videos as learning media to provide a more efficient learning experience where participants' engagement and motivations are enhanced. The research aims to increase participants' overall learning level, understanding level; motivation and communication skills. For this research, a collaborative environment has been built where students participate in a video sharing system allowing them to create their own summarized Videos from existing course video material. Students can then share these videos with other system participants with the ability to view, rate and comment on videos. Instructors upload the core video footage, which the students are able to edit and summarize. Two experiments were run with live modules within the Department of Informatics; a pilot study and full experiment. Feedback from the pilot study was used to develop the framework for the full study. The experiments involved pre and post participation surveys to measure satisfaction and awareness effects. Also, system participation data was used for analysis of engagement and other factors defining the outcomes of this experiment. The findings showed a considerable increase in student satisfaction regarding their understanding and motivation with video summarization tool used in the experiments. The results of [the] collaboration aspect of the experiment showed a slight increase in their satisfaction on their learning level, however, it had minimal effect on students' motivation and engagement as no significant difference was noted after using the system.

A cornerstone of much educational research in individualised and automated instruction (e.g., computer-based learning) is the assumption that learners be permitted to set the rate at which they work through the material to be learned. Experiments that have compared learning under conditions of self pacing (determined by the learner) and external pacing (determined by the experimenter), using a variety of tasks and populations, often have not supported this assumption. To evaluate the putative advantages of student self pacing in automated instruction, the studies in this thesis compared the effects of self-paced, and externally-paced, programmed instruction on student accuracy, retention efficiency, and satisfaction. Under self-pacing conditions, learners completely controlled the rate of progress through learning materials; that is, although the program paused when learners were required to provide answers, score answers, and proceed to the next item, it continued as soon as the learner pressed any key. External pacing was operationalised by programming a noncontingent 10-s postfeedback delay after every item; that is, learners could not progress to a subsequent item until the delay period was over. All relevant learning material for the current item was present during the delay. In a series of experiments using an alternating conditions design, learners completed approximately 40 sets of a programmed course in behaviour analysis (Holland & Skinner, 1961). A baseline of self-pacing conditions was followed by an experimental phase in which baseline conditions were randomly alternated with one or more experimental conditions. Later experiments also included a return to baseline conditions. In Experiments 1 and 2 externally-imposed delays resulted in greater accuracy than self pacing. This advantage occurred when the delays were accompanied by the study materials, but did not occur for a condition in which delays were presented without the learning material being visible. Hence, it was proposed that noncontingent postfeedback delays are effective because they provide a study opportunity which is otherwise not taken. In addition, imposing delays only slightly increased overall time to completion, and learners rated their satisfaction with external and self pacing similarly. Experiments 3 and 4 replicated the accuracy advantage found for external pacing, and showed also that material learned under these conditions was recalled better in both immediate and 1-month delayed posttests. These experiments also provided information about factors that influence efficiency during completion of materials. One of these factors was a requirement that, at the end of an instructional set, each question answered incorrectly be repeated until it was answered correctly (i.e., review feature). This is part of the standard implementation of programmed materials and had been employed in all conditions. In the earlier studies, externally-paced and self-paced conditions showed little difference in overall time to completion. It was apparent that although the externally-paced condition had an increased task time due to enforced delays, this condition did not take longer overall because more errors were made in self pacing, so more items were reviewed, and the overall time of a session was increased. Therefore, although imposing delays entailed a time cost, this was offset because it reduced the number of errors and time-consuming repeats. Experiment 4 demonstrated that when the review requirement was removed, noncontingent delays caused an increase in overall time to completion. Another factor determining efficiency was workrate during nondelay components of the task. Measures of the time learners spent responding, correcting responses, and continuing to subsequent frames, indicated that delays promoted faster workrates at each of these points. This was interpreted as evidence of a generalised escape motivation that is increased by being delayed and which offsets some of the time lost due to delays. The final two experiments investigated the effects of reviewing incorrect items on student performance because it had been a potential confound in previous experiments. Previously, both self-pacing and external-pacing conditions required subjects to repeat incorrect items until answered correctly. It is possible that because reviewing items increased time on task (like imposed delays), they also led to compensatory changes in workrate, and influenced timing and efficiency measures. Any such influence was not controlled across experimental conditions, however, because self pacing typically resulted in more errors and larger reviews, and any influence of review size on timing measures could not be separated from the effect of delays. It was found that, compared to a no-review condition, reviews reduced efficiency and had little influence on accuracy and retention. Hence, this feature was unlikely to have interacted with the delay variable in previous experiments. In conclusion, the results of the experiments show that self pacing reduced accuracy, retention, and workrates compared to external pacing. These studies indicate that learners often make poor choices about optimum learning conditions. They also show that small changes in the learning environment can result in consistent and substantial changes in learner performance, and that behaviour analysts have an important role to play in the design and implementation of instructional materials.

Includes bibliographical references. / 2 v. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Education, 1994

Thesis (M.Comp.)--Unitec New Zealand, 2007. / Includes bibliographical references (leaves 193-1980).