This dissertation presents a stochastic framework for modeling the degradation processes of components in complex engineering systems using sensor based signals. Chapters 1 and 2 discuses the challenges and the existing literature in monitoring and predicting the performance of complex engineering systems. Chapter 3 presents the degradation model with the absorbing failure threshold for a single unit and the RLD estimation using the first-passage-time approach. Subsequently, we develop the estimate of the RLD using the first-passage-time approach for two cases: information prior distributions and non-informative prior distributions. A case study is presented using real-world data from rolling elements bearing applications. Chapter 4 presents a stochastic methodology for modeling degradation signals from components functioning under dynamically evolving environmental conditions. We utilize in-situ sensor signals related to the degradation process, as well as the environmental conditions, to predict and continuously update, in real-time, the distribution of a component’s residual lifetime. Two distinct models are presented. The first considers future environmental profiles that evolve in a deterministic manner while the second assumes the environment evolves as a continuous-time Markov chain. Chapters 5 and 6 generalize the failure-dependent models and develop a general model that examines the interactions among the degradation processes of interconnected components/subsystems. In particular, we model how the degradation level of one component affects the degradation rates of other components in the system. Hereafter, we refer to this type of component-to-component interaction caused by their stochastic dependence as degradation-rate-interaction (DRI). Chapter 5 focuses on the scenario in which these changes occur in a discrete manner, whereas, Chapter 6 focuses on the scenario, in which DRIs occur in a continuous manner. We demonstrate that incorporating the effects of component interactions significantly improves the prediction accuracy of RLDs. Finally, we outline the conclusion remarks and a future work plan in Chapter 7.

The goal of this thesis is to introduce new matched field processors (MFPs) for estimating the source location and the environmental parameters of a shallow water waveguide in which the source transmits either broadband or narrowband random signals.

The problem of determining an objective means for assessing local characteristics of television subpictures in a Hadamard transform multicoder scheme is stated and discussed. Detailed investigations of transform domain coefficient statistical characteristics for different test images have been conducted. Both monochrome and colour signals were used, as well as different transform sizes and shapes. " Directing Indexes " are proposed which, depending on the inter-relationships among transform coefficients and groups of coefficients, direct each subpicture to the appropriate coder. Three indexes in the case of monochrome signals are proposed, each with its own computational procedures and application requirements. Necessary modifications and changes for application of some indexes on colour signals are also discussed. The proposed technique of indexing eliminates the necessity of equal distribution of subpictures among 'activity classes', a major disadvantage encountered in present activity index. Coders to be used with each directing index are devised and tested, subject to an arbitrary bit rate of 2 bits per pixel, with satisfactory performance compared with some published results for other techniques.

No description available.

Drivers are expected to traverse through an intersection in malfunctioning flash mode in the same manner as a stop-sign controlled intersection. Red/red flash corresponds to four-way stop control and yellow/red flash corresponds to two-way stop control. However, at a red flashing signal there is no assurance that a driver can see the cross street indication (i.e., yellow or red flash) and therefore does not know if the intersection is operating as a two-way or four-way flash. In addition, some drivers appear unclear on the rules at a flashing signal. This confusion makes the intersection more accident prone. This study builds upon several previous studies, using data extracted from existing files. The objective of this study is to determine the level of drivers' understanding of the flash control through an analysis of violation rates and types at recorded intersection in malfunction flash. Comparing these violation rates to those at comparable stop-control intersections will help illustrate the difference in drivers' understanding of these similar intersection control devices.

Thesis (Ph.D.)--Edith Cowan University, 2007. / Submitted to the Faculty of Computing, Health and Science. Includes bibliographical references.

Thesis (M.S.)--Ohio University, June, 2003. / Title from PDF t.p. Includes bibliographical references (leaves 102-108).

Diss. (sammanfattning) Stockholm : Karol. inst., 2006. / Härtill 5 uppsatser.

Thesis (Ph. D.)--University of Alabama at Birmingham, 2007. / Title from first page of PDF file (viewed June 23, 2008). Includes bibliographical references.

Thesis (Ph. D.)--University of Alabama at Birmingham, 2008. / Title from first page of PDF file (viewed Sept. 16, 2008). Includes bibliographical references.