The purpose of this investigation was to determine the effects of multimedia CAI on undergraduate PETE majors' teaching of the serve in tennis. The data were obtained from 18 undergraduate students enrolled in a PETE evaluation and assessment course at Virginia Tech. Subjects were stratified by gender and randomly assigned to three groups as Computer-Assisted Instruction (CAI) group (n=6), Teacher Instruction (TI) group (n=6), and Control (CG) group (n=6). The results of this study were gathered from three tests: Tennis Serve Content Knowledge Test, Tennis Serve Skill Analysis Test, Tennis Task Sequence Test. In addition, two six minutes micro teaching sessions were conducted and data was collected via Tennis Serve Pedagogical Content Knowledge (PCK) Assessment Sheet, and finally, an open ended survey was completed to understand students' attitudes toward CAI. There are two independent variables in this study. These are Computer-Assisted Instruction (CAI) and Teacher Instruction (TI). A pre-test and post-test experimental design was applied. The Kruskal-Wallis test was used to determine the differences among the three groups, and pairwise ranking with the Mann Whitney U test was conducted between all comparisons as a post hoc analysis. Moreover, the Wilcoxon Signed Rank test was used to determine pre-to post-test changes within the groups. Alpha set at p< 0.5. Overall, teacher instruction (TI) intervention was very dominant in the results. Teacher instruction (TI) group performed significantly in the tennis serve content knowledge test, tennis serve task analysis test, PCK-Appropriate cues, and PCK-Appropriate demonstration. However, CAI group was also successful in the tennis serve content knowledge test and PCK-Appropriate demonstration. Interestingly, none of the groups were successful in the tennis serve skill analysis test and PCK-Appropriate feedback. Finally, students' perception toward CAI was positive in general and students indicated that they would like to use CAI in other PETE method courses. However, some of the students reported that CAI was very repetitive, and also technical problems were reported. The results of this study indicated that CAI can be an effective way of instruction in certain conditions: CAI had significant effect on content knowledge and PCK-Appropriate demonstration. In conclusion, the 21st century will be an information age and computers will be an essential part of the education system in all grades and ages. Physical education teacher education programs and physical education lessons in K-12 education are no exceptions. Computers and instructional technology should be an integral part of PETE and K-12 physical education without sacrificing the physical activity. / Ph. D.

No description available.

The need to develop appropriate computer training techniques has led to an explosion of research in information systems. One of the most recent studies was conducted by Compeau and Higgins (1995) in which two training methods were examined in the context of Social Cognitive Learning Theory (Bandura, 1977, 1978). The training methods examined were traditional lecture-based training and behavior modeling. Based on various anomalies found in the Compeau and Higgins study, this paper introduced a moderating variable, task complexity, into their model and also attempted to replicate their original experiment. This study also incorporated an additional training method, Computer Aided Instruction (CAI), which was examined in an experiment by Gist, Schwoerer, and Rosen (1989). It was hypothesized that task complexity has a moderating effect on the relationships between behavior modeling and performance, between behavior modeling and self-efficacy, and between self-efficacy and performance. Finally, an empirical investigation was performed to determine the relative effectiveness of the three training methods examined. To test these hypothesized relationships, an experiment was conducted that examined prior performance, self-efficacy, outcome expectations, and actual performance at two levels of task complexity for each of the three training methods. The data were analyzed using a combination of multivariate and univariate analyses of variance and a structural equation modeling software package, AMOS©. Five of the original nine hypotheses from the Compeau and Higgins study were fully supported; however, none of the task complexity and only one of the avoidance behavior hypotheses were supported. Possible causes of this lack of support were multi-dimensionality of constructs or the need to examine task dimensions other than complexity. Relevant findings in this study included (1) a positive significant relationship between behavior modeling and final performance, (2) a positive significant relationship between prior performance and the endogenous constructs in the model: computer self-efficacy, outcome expectations, and final performance, and (3) a ranking of the three training methods in terms of effectiveness. Although behavior modeling produced the best performance results at all levels of task complexity, CAI was equally effective when the level of complexity was high. For low complexity tasks, however, CAI was the least effective method examined. / Ph. D.

La tenue résiduelle à l'impact basse vitesse est un critère dimensionnant des structures composites minces pour l'aéronautique. La majorité des travaux réalisés jusqu'ici porte sur l'analyse du comportement en zone courante. Ce travail élargit le domaine d'étude aux zones de variation d'épaisseur. L'objectif est d'étudier la tolérance aux dommages d'impact d'un stratifié comportant une zone de reprise de plis (ZRP) dans le cadre d'un dialogue essai/ calcul, en menant en parallèle une campagne d'essais expérimentaux et l'adaptation d'un modèle numérique de l'endommagement des composites.Le volet expérimental étudie successivement l'impact, la compression et la fatigue à R=-l après impact (CAI et FAI) d'éprouvettes comportant une ZRP. L'analyse des essais d'impact a permis d'identifier la résistance à l'impact et le mécanisme d'endommagement des éprouvettes. Ensuite, un outillage d'essai adapté à la géométrie des éprouvettes a été conçu pour les essais de CAI et de FAI. Les essais de compression montrent une tenue résiduelle statique après impact similaire à celle des éprouvettes sans perte de plis. Les essais de fatigue menés à 60 070 de la tenue résiduelle statique montrent une propagation des délaminages d'impact (en dessous du BVID) qui mène à la rupture des éprouvettes pour un nombre de cycles relativement faible. Alors que la tolérance aux dommages d'impact des ZRP sous chargement statique est comparable à celle des zones courantes lisses, on constate une forte vulnérabilité de ces zones sous chargement de fatigue.Le volet numérique a permis de tester l'approche DPM (Discrete Ply Model), développé lors de travaux précédents, sur une configuration particulière. Un maillage spécifique a été réalisé pour tenir compte des discontinuités de la ZRP. Au niveau de la loi matériau, une formulation unifiée de la rupture de fibres en traction/compression a été implémentée. Les résultats de la simulation d'impact sont en bonne corrélation avec les données expérimentales. Le modèle est capable de prédire la réponse globale de l'éprouvette ainsi que l'étendu des dommages internes. La modélisation de la CAI a permis de confirmer les mécanismes de rupture identifiés lors des essais. Ces résultats numériques sont remarquables puisqu' aucune modélisation locale particulière n'a été faite pour les arrêts de plis. L'approche DPM s'est révélée suffisamment robuste et bien adaptée à la modélisation de l'endommagement des stratifiés unidirectionnels. / The residual strength after low velocity impact is a sizing criterion of thin composite structures in aeronautics. The majority of work on the subject is focused on the analysis of plain laminates. This study expands the field of interest to tapered area. The objective is to study the impact damage tolerance of a laminate with ply drop-off using an experiment/ modelling dialogue: on one hand carrying experimental test campaign and on other hand adapting numerical modelling of composite damage. The experimental part successively examines the impact, compression and fatigue R=-l after impact (CAI and FAI) of specimens with ply drop-off. Analysis of the impact results has enabled the identification of impact resistance and damage mechanism. Then, a testing tool for CAI and FAI was specially designed to suit the geometry of the specimens. Compression tests show a static residual strength after impact similar to plain laminates. Fatigue tests carried at 60% of CAI strength show a propagation of impact delamination (below B VID). Failure of specimens occurs after a relatively small number of cycles. While the impact damage tolerance of tapered laminates is comparable to plain laminates under static loading, high vulnerability is observed under fatigue loading. The numerical part allowed to test the Discrete Ply Model (DPM), developed in previous works, on a particular configuration. A specific meshing was realized to account for the discontinuities in the ply drop-off area. Regarding the material law, a unified formulation of the fiber breakage in tension/ compression is implemented. Impact simulation results correlated well with the experimental data. The model is able to predict the overall response of the specimen and internal damage. The modeling of the CAI enabled to confirm the failure mechanisms identified during tests. These numerical results are remarkable since no particular local modeling has been realized for the ply drop-off area. DPM approach has proven robust enough and well suited to damage modeling of unidirectional laminates.

Controlled auto-ignition (CAI), also known as HCCI combustion in a gasoline engine has been extensively researched due to their potential of improved engine efficiency and low NOx emission. However, the combustion timing and the phasing of conventional CAI combustion depend on the in-cylinder condition, such as temperature and combustible mixture strength and thus cannot be directly controlled. In this study, direct DME (Dimethyl Ether) injection was adopted to increase the ignitability of premixed gasoline/air charge and to trigger the auto ignition of premixed charge. Re-breathing valve strategies were used to obtain hot internal EGR to eliminate a need of intake heating. Firstly, the pilot valve opening event, including its opening and closing timing, valve lift and dwell duration between the main valve event, was analysed by the WAVE simulation. Based on the analysis a re-breathing cam lobe was manufactured and installed on a Ricardo E6 engine to achieve the intake rebreathing and exhaust rebreathing operations. The intake re-breathing was realised by the pilot intake valve opening during the exhaust stroke and the exhaust re-breathing was achieved by the secondary exhaust valve opening during the intake stroke. Effects of the pilot intake valve open timing, 2nd DME injection timing, split DME injection ratio, air/fuel ratio and compression ratio were examined during the intake rebreathing operation. Then the performance and emission characteristics of DME assisted gasoline CAI combustion were examined during the exhaust re-breathing operation. Finally, results of the intake and exhaust re-rebreathing operations were compared to the conventional SI operation. The experimental study found that both the intake and the exhaust re-breathing operations provided enough heat to initiate DME assisted gasoline CAI combustion. The direct DME injection enabled to control the start of combustion and phasing. The quantity of the first DME injection showed greater effect than its timing, whereas the injection timing of 2nd DME injection had more dominant effect than its quantity. The exhaust re-breathing strategy provided stratified and hotter internal EGR that does not impact negatively on the volumetric efficiency because exhaust gas was re-breathed from the exhaust port during the intake stroke. High load of both CAI and SI baseline operations were limited by knocking combustion and their low load were limited by incomplete combustion. Exhaust re-breathing operation extended substantially the operational range of the DME assisted gasoline CAI combustion. Extremely low NOx emissions were obtained by DME/gasoline CAI operations. Most importantly, the exhaust rebreathing method produced dramatically improved overall efficiency of 43% compared to 28% of SI operation at a typical part-load operation of 4.0-5.0bar IMEP. It was also found that slightly improved efficiency and the extended operation range could be obtained by 33%:67% split DME injection ratio at higher load, while 67%:33% split DME injection ratio at lower load.

電腦輔助教學(Computer Assisted Instruction,簡稱CAI)係起源於1950年代末期的美國，並且在今日，CAI 儼然已成為全世界教育界共同的趨勢。 目前關於CAI的研究雖多，但尚無一多媒體作業研究教學輔助課程軟體，因此，本研究提出一以人類學習的基礎理論、資訊科技、使用者介面和傳播理論以及學科課程的內容與特質等五個構面和系統發展流程的多媒體CAI軟體發展 模式，以作為發展多媒體CAI軟體的理論與實作的依。 最後，本研究並依據此發展模式，實際製作一個作業研究課程教學軟體的雛形(prototype)系統，再針對此教學軟體系統進行評鑑，並藉由評鑑的結果以探討本研究教學軟體系統的可行性和本研究所提出的發展模式的有效性，以提供經驗作為日後發展多媒體CAI課程軟體的參考和依據。 / I first propose the multimedia CAI system develop model. And the model should contain the five factors, learning theory, communication theory, information technology, user interface, course and the system develop cycle. Then, I follow the multimedia CAI system develop model to develop the multimedia Operations Research CAI system. At last, the system has been assessed by the target user and the expert. And the result show the validity of the multimedia CAI system develop model.

The purpose of this study was to identify effective instructional programs for GED tests preparation for students in a large suburban school district. Three different nonrandom, unequal naturally occurring instructional groups at three different locations were examined. One group participated in a traditional instruction program, a second group in a test/retest program, and a third group in a computer-assisted program. The demographics of the district population, the GED population, and the individual study groups were catalogued and analyzed. The demographics of the GED population were similar to the district population but different from the GED passers. Student characteristics did affect GED success. Both quantitative and qualitative data were gathered. Random students in each of the three groups were interviewed about their experiences in GED preparation using a questionnaire. Quantitative data were analyzed using frequencies, means, correlations, and a multiple regression analysis. Since the GED credential is an alternative to the high school diploma, its use as a dropout alternative is important to every school district. The study found that instructional methods had little impact on students' success in receiving the GED credential. The overall success rate of students was low in each group. The student's reading achievement score, GPA, and IQ score were predictors of GED tests success. Little research has been done in the area of GED instruction; perhaps this lack of work is due to the known limited effectiveness of GED preparation. Districts hoping to build effective GED programs should screen students prior to admission to a GED program. High school GED instruction seems to be effective for students likely to be successful in the regular school setting but in need of an immediate credential because of pregnancy or parenting or the need to work full-time or the desire to begin college study. Districts should also design programs to help disenfranchised students in the regular program remain in school.

In the first part of studies, Controlled Auto-Ignition (CAI) combustion was investigated in a Ricardo E6 single cylinder, four stroke gasoline engine. CAI combustion is achieved by employing positive valve overlap configuration in combination with various compression ratios and intake air temperature strategies. The CAI operational region is limited by engine load due to knock and partial burned boundaries. The combustion characteristics and emissions are studied in order to understand the major advantages and drawbacks of CAI combustion with positive valve overlap. The enlargement of the CAI operational region is obtained by boosting intake air and external EGR. The lean-boosted operation elevators the range of CAI combustion to the higher load region, and the use of external EGR allows the engine to operation with CAI combustion in the mid range of region between boosted and N/A CAI operational range. The results are analyzed and combustion characteristics, performance and emissions are investigated. A Ricardo Hydra single cylinder, four stroke optical gasoline engine with optical access is then experimented to investigate CAI combustion through negative valve overlap configuration and an intake heater. The effects of direct fuel injection timings spark timings and air/fuel ratio are studied by means of simultaneous incylinder heat release study and direct visualization, chemiluminescence techniques which uses full, OH radical and CHO species. Both heat release analysis and chemiluminescence results have identified the pressure of minor combustion during the NVO period. Both the charge cooling and local air/fuel ratio effects are also investigated by varying the quantity of direct air injection.

論文(碩士)--香港中文大學,1973. / Ms. / Includes bibliographical references (p.281-290). / Thesis (M.A.)--Xianggang Zhong wen da xue. / 前言 --- p.1 / Chapter 第一章 --- 梁、蔡之生平 --- p.7 / Chapter （一） --- 梁氏之生平 --- p.9 / Chapter （二） --- 蔡氏之生平 --- p.47 / Chapter 第二章 --- 梁、蔡之交誼 --- p.85 / Chapter （一） --- 時務學堂時期 --- p.87 / Chapter （二） --- 流亡日本時期 --- p.107 / Chapter （三） --- 「洪憲」與雲南起義 --- p.137 / Chapter （四） --- 蔡 鍔 之 逝 世 / Chapter 第三章 --- 辛亥革命前後之梁、蔡 --- p.207 / Chapter （一） --- 蔡鍔返國及其活動 --- p.209 / Chapter （二） --- 蔡鍔與立憲黨之關係 --- p.237 / Chapter （三） --- 梁、蔡與民初政黨 --- p.254 / 參考書目 --- p.281

Thesis (Ph. D.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.