This master’s thesis is focused on current possibilities of solar energy utilization – especially on concentrating solar power systems – and their optimization using solar tracking systems to maximize energy gain. The thesis also deals with solar position algorithm and offers an Arduino based automatic dual axis solar tracker design which provides various solar devices the ability to pivot using stepper motors, DC motors or servos. The motion might be driven by calculated solar position or by actual illuminance.

International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / FAA is currently evaluating DGPS based CAT III Landing Systems for use as the next generation commercial aviation landing system standard. Any technique to validate such a DGPS based system must have at least equivalent accuracy. A laser position tracking system coupled with a high performance real-time computational capability was developed providing real-time analysis of performance. This real-time performance measurement system was key in enabling the quick completion of a large number of test approach and landings needed to achieve statistically accurate results.

Tracker-level fusion for video tracking combines outputs (state estimations) from multiple trackers, to address the shortcomings of individual trackers. Furthermore, performance evaluation of trackers at run time (online) can determine low performing trackers that can be removed from the fusion. This thesis presents a tracker-level fusion framework that performs online tracking performance evaluation for fusion. We first introduce a method to determine time instants of tracker failure that is divided into two steps. First, we evaluate tracking performance by comparing the distributions of the tracker state and a region around the state. We use Distribution Fields to generate the distributions of both regions and compute a tracking performance score by comparing the distributions using the L1 distance. Then, we model this score as a time series and employ the Auto Regressive Moving Average method to forecast future values of the performance score. A difference between the original and forecast returns the forecast error signal that we use to detect tracking failure. We test the method with different datasets and then demonstrate its flexibility using tracking results and sequences from the Visual Object Tracking (VOT) challenge. The second part presents a tracker-level fusion method that combines the outputs of multiple trackers. The method is divided into three steps. First, we group trackers into clusters based on the spatio-temporal pair-wise relationships of their outputs. Then, we evaluate tracking performance based on reverse-time analysis with an adaptive reference frame and define the cluster with trackers that appear to be successfully following the target as the on-target cluster. Finally, we fuse the outputs of the trackers in the on-target cluster to obtain the final target state. The fusion approach uses standard tracker outputs and can therefore combine various types of trackers. We test the method with several combinations of state-of-the-art trackers, and also compare it with individual trackers and other fusion approaches.

Location is a primary cue in many context-aware computing systems, and is often represented as a global coordinate, room number, or Euclidean distance various landmarks. A user?s concept of location, however, is often defined in terms of regions in which common activities occur. We show how to partition a space into such regions based on patterns of observed user location and motion. These regions, which we call activity zones, represent regions of similar user activity, and can be used to trigger application actions, retrieve information based on previous context, and present information to users. We suggest that context-aware applications can benefit from a location representation learned from observing users. We describe an implementation of our system and present two example applications whose behavior is controlled by users? entry, exit, and presence in the zones.

In the past, a considerable amount of research has been conducted into the effects of congruence between information display and task requirement on decision-making performance. The theoretical base for these works is the cost-benefit framework, which explains that the effort of decision makers will depend on the level of accuracy expected and the cost of the strategy employed to complete the task. In this research, the factor of self-efficacy is integrated into the cost-benefit framework for predicting decision making performance. An experiment was designed with two factors, display congruence and self-efficacy. The display congruence is a within-subject factor with 2 levels, high congruence and low congruence; the self-efficacy is a between-subject factor with 2 levels, high versus low. Subjects¡¦ eye movements were also tracked with an apparatus, eye tracker. A total of 30 subjects participated in the experiment and 20 were found to be valid based on an analysis of the eye movement data. These subjects were divided into high and low self-efficacy groups according to their scores of self-efficacy measurement. The results show that when the congruence is low, subjects spent significantly longer decision time and changed information acquisition direction than they do when the congruence is high, although there was no difference in decision accuracy between these two conditions. Self-efficacy is found to significantly predict goal commitment, intensity of effort, and decision accuracy. In addition, when subjects moved from the situation of high congruence display to the low congruence one, high self-efficacy subjects were found to increase their level of effort more than low self-efficacy subjects.

This research outlines a low-cost, low-power, arc-minute accurate star tracker that is designed for use on a CubeSat. The device is being developed at the University of Texas at Austin for use on two different 3-unit CubeSat missions. The hardware consists of commercial off-the-shelf parts designed for use in industrial machine vision systems and employs a 1024x768 grey-scale charge coupled device (CCD) sensor. The software includes the three standard steps in star tracking: centroiding, star identification, and attitude determination. Centroiding algorithms were developed in-house. The star identification code was adapted from the voting method developed by Kolomenkin, et al. Attitude determination was performed using Markley's singular value decomposition method. The star tracker was then tested with internal simulated star-fields. The resulting accuracy was less than an arcminute. It was concluded that this system is a viable option for CubeSats looking to improve their attitude determination. On-orbit demonstration of the system is planned when the star tracker flies on the planned CubeSat missions in 2013 or later. Further testing with external simulated star fields and night sky tests are also planned. / text

ITC/USA 2013 Conference Proceedings / The Forty-Ninth Annual International Telemetering Conference and Technical Exhibition / October 21-24, 2013 / Bally's Hotel & Convention Center, Las Vegas, NV / A position beaconing system for tracking small mammals, such as the Golden Lion Tamarin, was developed and tested. GPS acquires location of the animal. The system utilizes a VHF radio transmitter tuned to 144.390 MHz, which is located in the amateur radio band. APRS was selected as the protocol for position, transmission, and recovery. This allows users to benefit from any existing APRS enabled devices. The beacon was designed by attempting to optimize operational longevity and minimize size. Consequently, the system is implemented on a single board and enclosed for protection. As the system must be comfortable for the mammal, it was manufactured from lightweight components and enclosed in a plastic housing. To attach the case to the mammal, it is connected to a flexible, zig-zag, wearable antenna, which functions as a collar.

In this paper, we test the hypothesis that the introduction of Taiwan Top 50 Tracker Fund (TTT) would impact the market liquidity of its underlying stocks. We address this issue by adopting several volume-based and price-based liquidity measures to present the multi-dimension of liquidity. Our empirical results show that after the introduction of TTT, the standardized trading volume decreases and the market becomes more volatile for the underlying stocks. Both the quoted spread and the effective spread widen in the post-introduction period. These findings suggest deterioration of market liquidity for the underlying stocks. We then further follow Lin et al. (1995) to decompose the effective spread to examine the changes in spread components. We find a significant increase in the adverse selection component in contrast to a slight decline in the order processing cost. Overall, we find evidence that the liquidity of the underlying stocks tends to deteriorate after the introduction of TTT primarily because there is an increase in the cost of informed trading. Our finding is consist with the prediction of Subrahmanyam (1991) where the migration of liquidity traders to the basket securities raises the portion of informed traders in the market of underlying stocks and tends to increase the adverse selection risk and reduce the market liquidity of the underlying stocks.

Thesis (M.P.A.)--University of Hong Kong, 2000. / Includes bibliographical references (leaves 141-150).

Thesis (M.P.A.)--University of Hong Kong, 2000. / Includes bibliographical references (leaves 141-150). Also available in print.