Biometric authentication systems are used to guide the system security for many years in the computer world and make the user's identification easier and more convenient. Meanwhile, the systems encounter lots of challenges, attacks and threats, privacy protection and system management requirements, which affect the user's acceptance. Differing from the commonly used solutions, in this thesis the approach is to modify the system to meet these requirements, which results in a distributed architecture which can be composed in real time, and resolves the above challenges in one solution. A system prototype based on the proposed system architecture is designed as a sample for the reference of other system designers.

Due to persistent shortages of rehabilitation resources and services, collaboration tools for motion analysis have received great attention. High quality Internet connectivity and rich-content Web application platforms - Adobe Media Server and Flash Player, have created opportunities for integrating motion analysis into Flash based whiteboard and video conference applications to enhance rehabilitation services. For this thesis, clinical motion analysis software was created using Flash. The Motion Analysis Tools runs directly from a URL with a Web browser. The video synchronization procedure was supported by shared objects on a Flash Media Server. Program evaluation was conducted from accessibility and quality perspectives. Video synchronization error evaluation, angle and distance measurements, whiteboard functional, network latency impact, and ease of access were discussed during the evaluation phase. The Motion Analysis program can be access via Real-time Media Protocol (RTMP). A single TCP port was used for both signaling and media to maximize the chance of establishing a connection. Synchronization error was maintained at an acceptable level (maximum 160ms, average 49.3 ms, standard deviation 0.21). Average root mean square errors were 2.7 degrees for angle measures and 1.95 cm for length measures. The test results were consistent with video motion analysis results and within an acceptable range for rehabilitation motion analysis. This Web-based motion analysis approach provided an enhanced tool for quantitative motion analysis.

Pay-TV Satellite Broadcast Service is very common today. However, protecting signals from being pirated is a principal issue. That is done using a conditional access system. In this thesis, we introduce and analyze different existing conditional access system design methods. Modification of the current method is proposed, and significant performance improvement is obtained. Satellite communication and cryptology are studied theoretically, which enables us to design public key-based encryption/decryption techniques for satellite broadcast that can supply higher secret solutions. Our simulation results show that the new design system is superior and more practical.

A well known defect of the standard exponential back-off algorithm used in IEEE 802.11 is its short-term unfairness between users. A user will have high throughput shortly after a successful transmitting but the user will have a low throughput temporarily after backing off again and again because of multiple collisions. This variation of short-term throughput induces unacceptable delay variation for the users that have real-time service demands such as Audio or Video. Recently algorithms like Idle Sense [1] has been proposed to solve this problem by reducing the short-term unfairness between users. It lets each user adapt its probability p of accessing the channel to a predetermined optimal p* based on its observation of traffic on the channel. In this thesis, we discuss some improvements we made to Idle Sense by including a deterministic back-off of [(1 -- p)/p] time slots after a successful transmission. Our algorithm may be viewed as a combination of Idle Sense and Zero Collision [2]. Simulation results show the throughput our algorithm obtains is almost the same as that of Idle Sense but short-term unfairness is reduced. Packets of each user can be transmitted at much more regular intervals and in simulations for Voice over IP (VOIP), the number of VOIP users with a good Quality of Service (QoS) through a single access point can be substantially increased.

In agent-based e-commerce systems, most buying agents rely primarily on ranking algorithms to make purchase decisions. These algorithms are based on one or a combination of several features of goods information, such as price, seller's reputation, etc.; however, information quality is usually ignored. This leads to the problem that product information is retrieved without proper regard to their quality. Realizing the importance and necessity of information quality for buying agents, this thesis introduces an Information Quality (IQ)-based ranking approach. A model which combines information quality assessment with user expectation is proposed. An approach on representation and interpretation of information quality is also developed. Two sets of experiments are conducted to verify the applicability of the proposed model and explore the effectiveness of individual information quality dimensions. The experimental results show that information quality based ranking does lead to better user satisfaction. Keywords: Information quality, agent system, e-commerce

In this dissertation, Wavelet-ANN (Artificial Neural Network) and Wavelet-ESVR (Energy Singular Value Ratio) are proposed for detection and classification of faults in systems with periodical characteristics. Bearings in particular display such periodical characteristics. Bearings are one of the most critical components in rotary machinery and the majority of failures arise from defective bearings. Early warning in bearing deterioration is essential and it can prevent substantial machine downtime. In the first method an ANN is trained to diagnose bearing health by extracting information from discrete Wavelet coefficients. In the second approach, ESVRs are used to detect variations in the continuous Wavelets coefficients as symptoms of bearing health. Computer-simulated data and real bearing vibration data were then applied to perform initial testing and validation of these approaches. The test results show that the proposed methods are effectively detecting different bearing faults.

This thesis presents an adaptive technique that uses feedback to provide practical information during a planar near-field measurement scan. The feedback is used to decide with certainty when to terminate the planar near-field measurement process. The developed adaptive planar near-field method utilizes a rectangular spiral-type acquisition pattern to acquire the near-field measurements. At the end of each scan iteration, a set of decision functions are rapidly calculated which provide a quality measurement of the resulting far-zone transformation. The decision functions are based on the far-zone radiated patterns, directivity, and the fractional plane wave spectrum error. The decision functions were evaluated using actual planar near-field data set of five different antennas. These experiments have identified those decision functions that are directly related to antenna performance measures and would allow for the termination of the planar near-field test based on a set of relevant stopping conditions.

Performance management is a vital part of every organization for its success and long term survival in the current competitive global market place. An organization needs a sound performance management framework to analyze its data to make strategic and tactical decisions. The weaknesses in today's performance management frameworks are linked to their inability to integrate strategy formulation with implementation. In our thesis, we introduce D river Measure Models that can define cause-and-effect relationship between d river measures and Key Performance Indicators (KPIs) for effective performance management and strategic alignment. Driver Measure Models make the performance management more dynamic as the operational activities are linked to strategies. Another contribution of the thesis is the identification of mathematical techniques to quantify relationships between KPIs and driver measures. Thesis makes an effort to show how mathematical techniques can be used for planning and forecasting outcomes while changing strategies. After conducting analysis using the mathematical techniques, organization can arrive at a set of operational tasks associated to driver measures which need to be executed to achieve its optimal result. Finally, we identified the essential set of criteria that a performance management framework needs to address through a literature survey and a gap analysis of existing frameworks. We created an extension to the Balanced Scorecard framework based on Driver Measure Models and support for the management of external factors to address these criteria and compared it to existing frameworks using a case study.

No description available.

During the startup phase of a production process while statistics on the product quality are being collected it is useful to establish that the process is under control. Small samples $\{ n\sb{i}\} \sbsp{i=1}{q}$ are taken periodically for $q$ periods. We shall assume each measurement is bivariate. A process is under control or on-target if all the observations are deemed to be independent and identically distributed and moreover the distribution of each observation is a product distribution. This would be the case if each coordinate of an observation is a nominal value plus noise. Let $F\sp{i}$ represent the empirical distribution function of the $i\sp{-th}$ sample. Let $\overline {F}$ represent the empirical distribution function of all observations. Following Lehman (1951) we propose statistics of the form$${\sum\limits\sbsp{i = 1}{q}}\int\sbsp{-\infty}{\infty}\int\sbsp{-\infty}{\infty}(F\sp{i}(s,t) - \overline{F}(s)\overline{F}(t))\sp2 d\overline{F}(s,t)\eqno(1)$$The emphasis there, however, is on the case where $n\sb{i}\ \to\ \infty$ while $q$ stayed fixed. Here we study the following family of statistics$$S\sb{q}={\sum\limits\sbsp{i = 1}{q}}\int\sbsp{-\infty}{\infty}\int\sbsp{-\infty}{\infty}k\sb{q}(n, i, F\sp{i}(s,t),\overline{F}(s)\overline{F}(t))n\sb{i}dF\sp{i}(s,t)\eqno(2)$$in the above quality control situation, where $q\to\infty$ while $n\sb{i}$ stays fixed. (Abstract shortened by UMI.)