Thesis (Ph. D.)--Mississippi State University. Department of Computer Science and Engineering. / Title from title screen. Includes bibliographical references.

M. Tech. Electrical Engineering. / Proposes certain approaches aimed at improving handover from the users point of view, the benefits may include enhanced quality of service, avoidance of handover disruption and reduction of handover rate, irrespective of high traffic loads at the BSs.The proposed scheme improves the network performance by minimising the handover delay time and also enhancing the effective use of radio resources

M. Tech. Electrical Engineering. / Presents an IPv6-based mobility support scheme for vehicular scenarios. The focus of this study is on modelling of an efficient network layer handover scheme suitable for vehicular network environments. In order to achieve this, a Vehicular Fast handovers for Mobile IPv6 (VFMIPv6) network layer protocol has been proposed.

Real-time information that informs transit riders about transit schedules, next bus or train arrivals, and service alerts, is becoming increasingly available, particularly through internet-enabled smartphone applications. However, the extent of communication technology usage amongst transit riders, specifically their access to mobile applications and alternative technologies that can provide real-time information, is largely unknown. Without this information, transit agencies are risking investing in an alternative technology that may not sufficiently supply real-time information to as many as possible riders. The purpose of this study is to identify the differences in individual technology accessibility and prioritize investing in real-time information application development that mirrors the unique characteristics of transit riders. This recognition and development will allow a wider availability of real-time information amongst transit riders. Paired with an investigation of cellular phone usage among transit riders and the general American population, an analysis of Saint Louis Metro’s Onboard Survey was performed. Cross tabulations and chi-squared tests were conducted to examine riders’ communication technology usage. Binary logit models were used to understand how, and whether, the ownership of smartphone applications is dependent on various demographic factors. These analyses identified specific demographic groups that would benefit from supplemental technology methods more conducive to their particular information accessibility. Results showed that communication technology usage has risen substantially in recent years but a portion of riders are still without access to smartphone applications. Specific demographic groups (e.g., riders over 40 years of age) were less likely to own smartphones, and these results indicate that computer-based websites and IVR are the best supplementary alternatives for those groups.

Effective construction management involves real-time decisions regarding the progress of specific activities, the location of materials and equipment, and the construction site safety. The decision making process can be improved using real-time positioning technologies such as Radio Frequency Identification Device (RFID) systems, Global Positioning System (GPS), and Ultra Wide Band (UWB) sensors. While the GPS is not applicable to indoor positioning and RFID tags cannot provide a fully automated system for position location, the characteristics of UWB systems make this technology a strong candidate for a fully automated positioning system in an indoor construction environment. This thesis presents a comprehensive study of the performance of UWB systems in a controlled laboratory environment and in an institutional construction site in Waterloo, Canada as well as for a particular safety application. A primary objective of the research was to establish the accuracy of real-time position location under various conditions, including the effect of different construction materials (e.g., wood and metal), and to analyze changes in the accuracy of position location as construction progresses and the indoor environment physically evolves. Different challenges faced in implementing such a system in an active construction environment are addressed. Based on a statistical analysis of laboratory data, and considering the construction site experience, the reliability of the UWB positioning system for the aforementioned environments is discussed. Furthermore, an automated safety system is proposed using the real-time UWB positioning technology. Based on the error modeling of the UWB position location, an optimum alarming algorithm is designed for the proposed safety system and the reliability of such system is evaluated through a statistical analysis.

The main goal of this thesis is to develop real-time computer vision algorithms in order to detect and to track targets in uncertain complex environments purely based on a visual sensor. Two major subjects addressed by this work are: 1. The development of fast and robust image segmentation algorithms that are able to search and automatically detect targets in a given image. 2. The development of sound filtering algorithms to reduce the effects of noise in signals from the image processing. The main constraint of this research is that the algorithms should work in real-time with limited computing power on an onboard computer in an aircraft. In particular, we focus on contour tracking which tracks the outline of the target represented by contours in the image plane. This thesis is concerned with three specific categories, namely image segmentation, shape modeling, and signal filtering. We have designed image segmentation algorithms based on geometric active contours implemented via level set methods. Geometric active contours are deformable contours that automatically track the outlines of objects in images. In this approach, the contour in the image plane is represented as the zero-level set of a higher dimensional function. (One example of the higher dimensional function is a three-dimensional surface for a two-dimensional contour.) This approach handles the topological changes (e.g., merging, splitting) of the contour naturally. Although geometric active contours prevail in many fields of computer vision, they suffer from the high computational costs associated with level set methods. Therefore, simplified versions of level set methods such as fast marching methods are often used in problems of real-time visual tracking. This thesis presents the development of a fast and robust segmentation algorithm based on up-to-date extensions of level set methods and geometric active contours, namely a fast implementation of Chan-Vese's (active contour) model (FICVM). The shape prior is a useful cue in the recognition of the true target. For the contour tracker, the outline of the target can be easily disrupted by noise. In geometric active contours, to cope with deviations from the true outline of the target, a higher dimensional function is constructed based on the shape prior, and the contour tracks the outline of an object by considering the difference between the higher dimensional functions obtained from the shape prior and from a measurement in a given image. The higher dimensional function is often a distance map which requires high computational costs for construction. This thesis focuses on the extraction of shape information from only the zero-level set of the higher dimensional function. This strategy compensates for inaccuracies in the calculation of the shape difference that occur when a simplified higher dimensional function is used. This is named as contour-based shape modeling. Filtering is an essential element in tracking problems because of the presence of noise in system models and measurements. The well-known Kalman filter provides an exact solution only for problems which have linear models and Gaussian distributions (linear/Gaussian problems). For nonlinear/non-Gaussian problems, particle filters have received much attention in recent years. Particle filtering is useful in the approximation of complicated posterior probability distribution functions. However, the computational burden of particle filtering prevents it from performing at full capacity in real-time applications. This thesis concentrates on improving the processing time of particle filtering for real-time applications. In principle, we follow the particle filter in the geometric active contour framework. This thesis proposes an advanced blob tracking scheme in which a blob contains shape prior information of the target. This scheme simplifies the sampling process and quickly suggests the samples which have a high probability of being the target. Only for these samples is the contour tracking algorithm applied to obtain a more detailed state estimate. Curve evolution in the contour tracking is realized by the FICVM. The dissimilarity measure is calculated by the contour based shape modeling method and the shape prior is updated when it satisfies certain conditions. The new particle filter is applied to the problems of low contrast and severe daylight conditions, to cluttered environments, and to the appearing/disappearing target tracking. We have also demonstrated the utility of the filtering algorithm for multiple target tracking in the presence of occlusions. This thesis presents several test results from simulations and flight tests. In these tests, the proposed algorithms demonstrated promising results in varied situations of tracking.

The electrocardiograph (ECG) is a common clinical and biomedical research tool used for both diagnostic and prognostic purposes. In recent years computer aided analysis of the ECG has enabled cardiographic patterns to be found which were hitherto not apparent. Many of these analyses rely upon the segmentation of the ECG into separate time delimited waveforms. The instants delimiting these segments are called the

Thesis (Ph. D.)--Aerospace Engineering, Georgia Institute of Technology, 2008. / Committee Chair: Johnson, Eric; Committee Co-Chair: Calise, Anthony; Committee Member: Prasad, J.V.R.; Committee Member: Tannenbaum, Allen; Committee Member: Tsiotras, Panagiotis.

Thesis (M.S.) -- Mississippi State University. Department of Computer Science and Engineering. / Title from title screen. Includes bibliographical references.

Thesis (Ph. D.)--State University of New York at Binghamton, Thomas J. Watson School of Engineering and Applied Science, Department of Mechanical Engineering, 2008. / Includes bibliographical references.