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by Ng Wing-tim, Daniel, Yeung Siu-ming. / Thesis (M.B.A.)--Chinese University of Hong Kong, 1995. / Includes bibliographical references (leaves 113). / ABSTRACT --- p.iii / TABLE OF CONTENTS --- p.v / LIST OF EXHIBITS --- p.viii / Chapter / Chapter I. --- INTRODUCTION --- p.1 / Economic Background --- p.1 / PRC --- p.1 / Hong Kong --- p.3 / Basic Telecommunications Structure --- p.4 / PRC --- p.4 / Hong Kong --- p.8 / Basic Cellular Environment --- p.8 / PRC --- p.9 / Hong Kong --- p.11 / Comparisons between PRC and Hong Kong --- p.12 / Characteristics of the Cellular Market --- p.13 / PRC --- p.13 / System Summary Table --- p.16 / Chapter II. --- CELLULAR NETWORKS --- p.17 / System Growth --- p.19 / Migration to Digital Era --- p.21 / GSM --- p.21 / CDMA --- p.23 / D-AMPS --- p.24 / E-TDMA --- p.24 / Market Analysis in Selected Areas --- p.25 / Beijing --- p.26 / Shanghai --- p.29 / Guangdong Province --- p.31 / Hong Kong --- p.33 / Chapter III. --- CELLULAR TERMINAL MARKET --- p.36 / Market Potential --- p.36 / PRC --- p.36 / Hong Kong --- p.37 / Subscriber Distribution --- p.37 / PRC --- p.38 / Hong Kong --- p.38 / Subscriber Growth --- p.40 / PRC --- p.41 / Hong Kong --- p.42 / Black Market --- p.43 / PRC --- p.43 / Hong Kong --- p.44 / Roaming --- p.45 / PRC --- p.45 / Hong Kong --- p.46 / Chapter IV. --- CUSTOMERS --- p.48 / Preference --- p.48 / Consumption Trends --- p.49 / Segments --- p.50 / Subscriber Charges --- p.51 / Chapter V. --- COMPETITORS --- p.52 / Cellular Infrastructure Suppliers --- p.52 / PRC --- p.52 / Hong Kong --- p.56 / Cellular Terminal Suppliers --- p.57 / PRC --- p.57 / Hong Kong --- p.60 / Product Comparisons --- p.61 / Market Shares --- p.61 / PRC --- p.61 / Hong Kong --- p.62 / Pricing Trend --- p.63 / PRC --- p.63 / Hong Kong --- p.64 / Competition from CT2 --- p.64 / PRC --- p.64 / Hong Kong --- p.65 / Chapter VI. --- TECHNOLOGY --- p.67 / Migration to Digital Era --- p.67 / PRC --- p.67 / Hong Kong --- p.68 / New Generation on Mobile Terminal --- p.69 / PRC --- p.69 / Hong Kong --- p.70 / Chapter VII. --- ECONOMIC ENVIRONMENT --- p.71 / PRC --- p.71 / Hong Kong --- p.73 / Chapter VIII. --- LEGAL ENVIRONMENT --- p.75 / PRC --- p.75 / Migration into Deregulated Environment --- p.75 / Government Policy --- p.77 / Difficulties Encountered in Deregulation --- p.78 / Hong Kong --- p.80 / Law in Hong Kong --- p.81 / Telecom Deregulation --- p.81 / Mobile Telecommunications Service --- p.82 / Chapter IX. --- RECOMMENDATIONS FOR A NEW ENTRANT INTO THE MARKET --- p.84 / PRC --- p.84 / Type approval --- p.84 / Import --- p.86 / Distribution --- p.87 / Pricing --- p.87 / Local Production --- p.88 / Hong Kong --- p.89 / EXHIBIT --- p.90 / BIBLIOGRAPHY --- p.113

This work describes the development of a technique for the evaluation of the performance of a product's physical user interface. The technique is intended to combine the best features cat conventional user group testing with those of computer based biomechanical modelling. A requirement for the new technique exists as social pressure demands that consumer products he optimised for users with a wide range of physical capabilities, while shortening product lifecycles leave less time for extensive user evaluation programmes. A demonstration system was developed, based upon the use of an electromagnetic tracking system to gather upper limb motion data and a two segment, rigid link biomechanical model. Experimental work was carried out to test the effectiveness of the system at following limb movements and average error in reconstruction of hand position from segment angle data was 62mm (Standard deviation 41 mm) The modelling system was applied to the assessment of two types of product: cutlery and drinking vessels and the effectiveness of various statistical techniques in allowing the rapid identification of important design parameters was assessed. The use of Taguchi's smaller-the-better signal to noise ratio was found to be effective for the measurement of the effect of product design on shoulder and elbow forces. Cutlery with enlarged handles designed to reduce grip strength requirements tended to increase forces at the shoulder. The method was also applied to an interface optimisation problem involving the design of a lever mechanism. Partial factorial design was used to minimise experimental cost during the assessment of multiple factors, but strong interactions were detected between interface parameters, reducing the value of the analysis. The overall height of the lever handle relative to the user's shoulder was found to be the most significant design factor, with an optimum operating situation existing where the lever was low enough to require almost full extension of the elbow during use. The work concludes that biomechanical analysis holds further promise for the optimisation of interface parameters, provided the high experimental cost involved with present techniques can be reduced.

Digitized by Kansas Correctional Industries

Digitized by Kansas Correctional Industries

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The exposure to fumes and gases is one of the hazards associated with welding operations. Apart from research conducted on the mechanism of fume and gas formation and the relationship between fume formation rates and common welding parameters, little is known about the exposure process during welding. This research project aimed to identify the factors that influence exposure, develop an understanding of their role in the exposure process and through this understanding formulate strategies for the effective control of exposure during welding. To address these aims a literature review and an experimental program was conducted The literature review surveyed epidemiological, toxicological and exposure data. The experimental program involved three approaches, the first, an evaluation of the factors that influence exposure by assessing a metal inert gas/mild steel welding process in a workshop setting. The second approach involved the study of exposure in a controlled environment provided by a wind tunnel and simulated welding process. The final approach was to investigate workplace conditions through an assessment of exposure and control strategies in industry. The exposure to fumes and gases during welding is highly variable and frequently in excess of the health based exposure standards. Exposure is influenced by a number of a factors including the welding process, base material, arc time, electrode, arc current, arc voltage, arc length, electrode polarity, shield gas, wire-to-metal-work distance (metal inert gas), metal transfer mode, intensity of the UV radiation (ozone), the frequency of arc ignitions (ozone), thermal buoyancy generated by the arc process, ventilation (natural and mechanical), the welding environment, the position of the welder, the welders stance, helmet type, and helmet position. Exposure occurs as a result of three processes: the formation of contaminants at or around the arc region; their transport from the arc region, as influenced by the entry and thermal expansion of shield gases, the vigorous production of contaminants, thermal air currents produced by the heat of the arc process, and ventilation; and finally the entry of contaminants into the breathing zone of the welder, as influenced by the position of the welder, the welders stance, helmet type, and the helmet position. The control of exposure during welding can be achieved by several means: through the selection of welding parameters that generate low contaminant formation rates; through the limitation of arc time; and by isolating the breathing zone of the welder from the contaminant plume through the use of ventilation, welder position or the welding helmet as a physical barrier. Effective control is achieved by careful examination of the workplace, the selection of the most appropriate control option, and motivation of the workforce.

The market for Wireless Local Area Networks (WLANs) has experienced tremendous growth over the last few years and this trend is expected to continue in the future. This growth is due to the fact that wireless LANs provide several benefits including mobility, efficiency, and accuracy. In addition, the cost of installation for wireless LANs is several orders of magnitude lower than with traditional wired LANs due to reduced cabling costs. The two major components of a WLAN are Access Points (APs) and Radio Cards (RCs). Efforts have been made in the past to assess the performance of different APs and RCs from different vendors. However, these evaluations have been restricted to tests of interoperability and roaming. Tests to assess performance with respect to range, throughput, and power consumption are less common. Moreover, these tests are usually performed using homogeneous test beds (i.e., hardware components belong to the same vendor). The objective of this research was to assess how commercial-off-the-shelf (COTS) WLAN systems perform with respect to interoperability, roaming ability, power consumption, throughput, and range. In order to accomplish this, a test procedure composed of five experiments was developed. The evaluation was performed not only on homogeneous systems but also on systems constructed with hardware components from different vendors (i.e., heterogeneous). The results of the performance tests indicated that the different AP, RC, and their combinations, significantly affect the performance of the WLAN systems with respect to range, throughput, and power consumption. No significant differences were observed in the WLAN systems with respect to interoperability or roaming. The results of this research will help decision makers in understanding the key parameters that have to be considered when selecting WLAN equipment. In practice, however, it would be difficult for decision makers to determine which vendor of WLAN equipment has the best solution without actual testing. / Graduation date: 2003

Over the past three decades, instances of childhood obesity have tripled in the United States and are recognized as a serious public concern that requires action. Environmental factors have been identified as potential influences on the physical activity behavior of children; availability of equipment is one of these factors. The overall purpose of this dissertation was to examine availability of equipment as an environmental influence on a child’s physical activity behavior. The two environments where children spend the major of time, home and school, were evaluated for equipment availability and increased physical activity. Three studies were conducted to complete this purpose. In Manuscript 1, a systematic literature review was conducted, which included electronic databases as well as reference lists and author’s works as relevant. Only studies which measured home and school environments as factors in physical activity of children ages 5-12 were included. The review was conducted to determine the theoretical framework most used. Of the thirty-one studies reviewed, 67% showed little or no theoretical framework driving the study. Theoretical framework and models based on theory is needed to advance the field and this body of literature. In Manuscript 2, a systematic literature review was conducted which included electronic databases as well as reference lists and author’s works as relevant. Only studies which measured home and school environments and highlighted the availability of equipment as a factor in physical activity of children ages 5-12 were included. Of the twenty-one studies reviewed, only 14% clearly defined “equipment” and how it was measured for the particular study. With multiple definitions and confusion when comparing studies, standardization in this area is desperately needed. Manuscript 3, analyzed data from a larger study, NIH, Student Wellness Assessment and Advocacy Project (SWAAP), conducted in Waller county Texas, 2010. The results demonstrated which pieces of equipment in the home environment were available and the percentage of use. School environments were measured for availability of equipment and facilities. A linear regression analysis determined that being of Hispanic race was significant in less physical activity in an average seven day period. Given that children spend up to 80% of their day at home or school, influences in these two environments are extremely important to the development of physical activity behaviors. Future studies involving the availability and use of equipment should clearly define the type of equipment used or observed. In cases of intervention studies type and amount need to be clearly defined as well as assessment of its effect on physical activity in children. Several studies have been conducted for the specific age group of 6-12 year olds and their physical activity and multiple factors involved availability of opportunities for physical activity. Of those factors equipment availability has been shown to influence physical activity as well as not influence these opportunities. Standardization of the term equipment and how it is measured will allow researchers to have a clearer picture of the role that equipment plays in opportunities for children to be physically active.

Thesis (M.S.)--West Virginia University, 2001. / Title from document title page. Document formatted into pages; contains viii, 121 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 84-86).