Virtual reality-based instruction such as virtual worlds, games, and simulations are becoming very popular in K-12 and higher education. Three manuscripts that report the results of investigations of these increasingly prevalent instructional media were developed for this dissertation. The purpose of the first study, a meta-analysis, was to analyze the instructional effectiveness of virtual reality-based instruction when compared to the traditional methods of instruction. In addition, this study also explored selected instructional design features of the virtual learning environment that moderated the relationship between instructional method and the academic achievements. Analyses of 63 experimental or quasi-experimental studies that studied learning outcomes of virtual reality-based instruction in K-12 or higher education settings yielded a mean effect size of g = 0.47 (SE = 0.02) suggesting that virtual reality-based instruction is an effective medium of delivering instruction. Further analyses examined factors that influence its effectiveness. The purpose of the second study was to examine a model of the impact of a 3-D desktop virtual reality environment on the learner characteristics (i.e. perceptual and psychological variables) that can enhance chemistry-related learning achievements in an introductory college chemistry class. A theoretical model of the relationships of features of 3-D virtual reality environments and students' experiences in the environments to outcomes on a chemistry learning test and measures of spatial ability and self-efficacy was tested using structural equation modeling. Usability strongly mediated the relationship between 3-D virtual reality features, spatial orientation, self-efficacy, and presence. Spatial orientation and self-efficacy had a statistically significant, positive impact on the chemistry learning test. The purpose of the third study was to investigate the potential of Second Life (SL), a 3-D virtual world, to enhance undergraduate students? learning of a foundational chemistry concept, spatial ability, and self-efficacy. A quasi-experimental pretest-posttest control group design was used. A total of 387 participants completed three assignment activities either in Second Life or using 2-D images. The difference between the scores of 3-D virtual environment-based group and the 2-D images-based group was not statistically significant for any of the measures.

The main aim of this study is to develop three dimensional models for micro flow-field plate of PEMFC and use numerical simulations to discuss the reliability of micro flow-field plate which works in real. A crack exists in the plate is loaded by the shear force, which is produced by the fuel H2 enter from inlet, and will propagate. The Ag, which is used to collect the electrons, will peel off and the efficiency of fuel cell will decrease. The commercial package software ANSYS was used to simulate the stress state around crack tip. Three modes of stress intensity factors K£L, K£L£L and K£L£L£L, were calculated in order to describe the stressed behavior of crack. Finally, the inlet pressure, geometry of crack and channel size is changed and Taguchi method with ANOVA is used to find the factors which influence the stressed behavior of crack most. The simulation results show that K£L and K£L£L are influenced most by geometry of crack and K£L£L£L is influenced more by geometry of crack and channel size

In this dissertation, the design and analyses of an extremely scalable distributed multicomputer architecture, using optical interconnects, that has the potential to deliver in the order of petaFLOP performance is presented in detail. The design takes advantage of optical technologies, harnessing the features inherent in optics, to produce a 3D stack that implements efficiently a large, fully connected system of nodes forming a true 3D architecture. To adopt optics in large-scale multiprocessor cluster systems, efficient routing and scheduling techniques are needed. To this end, novel self-routing strategies for all-optical packet switched networks and on-line scheduling methods that can result in collision free communication and achieve real time operation in high-speed multiprocessor systems are proposed. The system is designed to allow failed/faulty nodes to stay in place without appreciable performance degradation. The approach is to develop a dynamic communication environment that will be able to effectively adapt and evolve with a high density of missing units or nodes. A joint CPU/bandwidth controller that maximizes the resource allocation in this dynamic computing environment is introduced with an objective to optimize the distributed cluster architecture, preventing performance/system degradation in the presence of failed/faulty nodes. A thorough analysis, feasibility study and description of the characteristics of a 3-Dimensional multicomputer system capable of achieving 100 teraFLOP performance is discussed in detail. Included in this dissertation is throughput analysis of the routing schemes, using methods from discrete-time queuing systems and computer simulation results for the different proposed algorithms. A prototype of the 3D architecture proposed is built and a test bed developed to obtain experimental results to further prove the feasibility of the design, validate initial assumptions, algorithms, simulations and the optimized distributed resource allocation scheme. Finally, as a prelude to further research, an efficient data routing strategy for highly scalable distributed mobile multiprocessor networks is introduced.

Pointe du Hoc overlooking the English Channel in Normandy, France was host to one of the most important military engagements of World War II. While the site is a valuable historic cultural resource, it is vulnerable to cliff collapses that already have endangered the observation post and Rudder?s command post. The observation post has been closed to visitors for some time due to safety concerns. Geophysical techniques have been used increasingly in recent years for slope stability investigation purposes. The objective of this study is to apply advanced 3?D resistivity tomography toward a detailed site stability assessment with special attention to the two at-risk buildings. 3?D resistivity tomography datasets at Pointe du Hoc in the presence of extreme topography and dense cultural clutter have been successfully acquired, inverted, and interpreted. The cliff stability in the areas around the two at?risk buildings has been analyzed. A hazard assessment scheme has been designed in which regions of high resistivity are interpreted as zones of open, dry fractures with a moderate mass movement potential. Regions of low resistivity are zones of wet, clay?filled fractures with a high mass movement potential. The observation post tomography results indicate that the highest mass movement hazard appears to be associated with the marine caverns at the base of the cliff that are positioned at the point of strongest wave attack. These caverns likely occupy the future site of development of a sea arch which will definitely threaten the observation post building. A high probability of a soil wedge failure is on the east?facing cliff edge close to the observation post that could damage or destroy the building. The mass movement potential at the Rudder?s command post area is low to moderate. The greatest risk is associated with soil wedge failures at the top of the cliffs. The resistivity geophysical data add great value to the natural geohazard assessment at Pointe du Hoc and constitute an integral component of an interdisciplinary approach to the problem of cultural resource preservation at the site. Geophysics is a non?invasive and relatively inexpensive technology that provides unique constraints which are unobtainable using traditional engineering geology methods for site characterization. However, the technology is difficult to master and the inherent limitations must be carefully understood to ensure a reliable geotechnical interpretation.

Mathcad hat sich bereits als benutzerfreundliche Mathematiksoftware in vielen Industriezweigen etabliert. An der Professur Maschinenelemente der TU Chemnitz werden mit Hilfe dieser Software Simulationsprogramme für Pkw-Klimaanlagen erstellt. Bei der Analyse und Optimierung von Produkten, wie z.B. dem Kältemittelverdichter, kann es für den Anwender hilfreich sein, den zu untersuchenden Mechanismus und die daran wirkenden Kräfte räumlich zu visualisieren. Dies kann, sofern ein CAD Modell vom Mechanismus vorhanden ist, beispielsweise mit der Software Pro Engineer erfolgen. Jedoch ist es auch möglich, ohne Zusatzsoftware mit einer sehr einfachen Methode Körper und Mechanismen direkt in Mathcad dreidimensional darzustellen und zu animieren. Anhand einiger Beispiele wird die Vorgehensweise in der Präsentation detailliert erläutert.

The purpose of the study was to provide a comprehensive framework that explains how consumer experiences within new, innovative media affect advertising effectiveness. Several concerns about previous advertising models motivated this study. For instance, advertising models traditionally have focused on message recipients’ characteristics and information processes, ignoring the significant role of media in understanding advertising effectiveness. In addition, recently developed advertising models dealing with the impact of media have been narrowly applied to a specific medium, the Internet, and have focused largely on interactivity. The proposed model and our findings highlighted the prominent roles of media novelty and presence in enhancing advertising effectiveness in an innovative, new medium that emphasizes vividness, stereoscopic 3-D. The novelty effect, created by the newness of the medium, had the power to attract viewers’ attention and the increased attention enhanced their sense of presence, the experience of being plunged into a new virtual world that advertisers constructed. The findings demonstrated that these sequential relationships can result in positive measures of advertising effectiveness, such as improved product knowledge and increased enjoyment, and ultimately more favorable attitudes toward the ad. Also our findings revealed that an irritation, such as cybersickness resulting from the stereoscopic 3-D, can hinder ad viewers’ communication processes and reduce their attention to the ad and their enjoyment of it. The model predicted that user characteristics, such as innovativeness, curiosity, and previous experience with the medium, would affect the process, but no effects were found. The current research provided advertising practitioners and researchers with opportunities to consider the significant role of media, especially innovative media, in assessing overall advertising effectiveness. For managers, it highlighted the potential of stereoscopic 3-D technology as an emerging advertising vehicle. Given the rapid changes in the media environment, it is increasingly important to understand the important roles that media play in advertising effectiveness. / text

In this thesis, an innovative algorithm for improving the accuracy of variational space-time stereoscopic reconstruction of ocean surfaces is presented. The space-time reconstruction method, developed based on stereo computer vision principles and variational optimization theory, takes videos captured by synchronized cameras as inputs and produces the shape and superficial pattern of an overlapped region of interest as outputs. These outputs are designed to be the minimizers of the variational optimization framework and are dependent on the estimation of the camera parameters. Therefore, from the perspective of computer vision, the proposed algorithm adjusts the estimation of camera parameters to lower the disagreement between the reconstruction and 2-D camera recordings. From a mathematical perspective, since the minimizers of the variational framework are determined by a set of partial differential equations (PDEs), the algorithm modifies the coefficients of the PDEs based on the current numerical solutions to reduce the minimum of the optimization framework. Our algorithm increases the tolerance to the errors of camera parameters, so the joint operations of our algorithm and the variational reconstruction method can generate accurate space-time models even using videos captured by perturbed cameras as input. This breakthrough prompts the realization of ocean surface reconstruction using videos filmed by remotely-controlled helicopters in the future. A number of techniques, technical or theoretical, are explored to fulfill the development and implementation of the algorithm and relative computation issues. The effectiveness of the proposed algorithm is validated through the statistics applied to real ocean surface reconstructions of data collected from an offshore platform at the Crimean Peninsula, the Black Sea. Moreover, synthetic data generated using computer graphics are customized to simulate various situations that are not recorded in the Crimea dataset for the demonstration of the algorithm.

Thesis (M.F.A.)--Rochester Institute of Technology, 1988. / Includes bibliographical references.

Thesis (M.S.)--Ohio State University, 2008. / Title from first page of PDF file. Includes bibliographical references (p. 54-56).

Thesis (M.S.)--Miami University, Dept. of Botany, 2004. / Title from first page of PDF document. Includes bibliographical references (p. 31-33).