This study aims to design a novel inserted welding tool to friction stir spot weld SS400 low carbon steel sheets of 4mm thickness. In order to enhance the efficiency of frictional heat generation and to enhance the quality of the welding spot, the welding tool based on a cylindrical tungsten carbide and is inserted by a SS400 low carbon cylinder. The welding apparatus composed of a vertical milling machine and a welding platform that can keep the load between tool and workpiece constant. The plunge load is 8kN and there's no inclination angle on the tools. Welding temperature and the tool plunge depth are measured by thermelcouples and a displacement meter. ¡@¡@At the tool rotational speed of spindle of 900rpm and welding for 60 seconds, the temperature rising rate of the tools with 5 mm and 10 mm inserted material are 5.28 times and 6.31 times greater than the one without insert. While they are 1.36 and 1.42 times greater than at 1200rpm.At the tool rotational speed of spindle of 900rpm and welding for 300 seconds, themaximun welding temperature the tools with 5 mm and 10 mm inserted material can reach are 59¢J and 412¢J higher than the one without insert. While they can reach 35.6¢J and 197.6¢J greater than at 1200rpm. According to the tensile test, the shear failure loads of clad steel plates increase 11.3kN and 15.5kN by using tools with 5 mm and 10 mm inserted material at 900rpm for 60 seconds, and increase 7.6kN and 18.3kN by using tools with 5 mm and 10 mm inserted material at 1200rpm.

High efficient optical spot size converter (SSC) is one of the most important building blocks for dense optical interconnection network and high-speed optical fiber communications due to efficient optical power transfer between different optical modules. Using tapered optical direction coupler (TODC) as SSC can reduce the dimension with high efficiency because of resonant condition and tapered structure. However, the strong dependence of operation on wavelength leads to narrow band operation, reducing the usage of wavelength division multiplexer (WDM) technique for upgrading optical data capacity through optical spectrum. In this work, based on multi- resonant points of TODC, a broadband SSC integrated with optical electroabsorption modulator (EAM) is proposed, designed, and fabricated. By tapering quantum well of the top active waveguide (AW), the integration with bottom passive waveguide (PW) can form a TODC. With the tapered structure, the gradually varied effective index forms a resonant point along wave propagation, inducing strong coupling, collecting optical power after resonant point, and thus leading to high efficient coupling. With multi-section of resonant conditions and also tapered structure, broadband operation can be realized. Through 3 section of tapered AW of TODC, the calculated coupling efficiency from bottom PW with larger than 70% is found for the regime of 1530nm~1550nm wavelength. The EAM-integrated SSC is also fabricated. With counter direction of optical coupling, the measured photocurrent in EAM shows a broadband of flap coupling from 1570nm~1585nm is observed, suggesting the multi-section TODC can bring out broadband operation.

In this thesis, we analyze the simplest optical imaging system: a ball lens. The traditional method of using a geometric optics analysis on an optical system only gives the roughest qualitative solution due to the lack of consideration of wave properties. Therefore, for accurate quantitative results, we need to analyze said system with a complete wave theory approach. The reason that we chose a ball lens as the focus of this research is due to its spherical symmetry properties which allows us to rigorously investigate it with different analytic methods. We will apply geometric optics, Fourier optics, scalar wave optics, and electromagnetic optics methods to compute the point spread functions (PSF) of a ball lens under the assumption that the point source is isotropic. We will follow up by predicting the spot sizes that correspond to each mean. First, with geometric optics (GO), we apply the analytic ray tracing method to correlate the origins of light rays passing through the ball lens to their respective positions on the receptive end. We can then evaluate the energy distribution function by gathering the density of rays on image plane. Second, in the theory of Fourier optics (FO), to obtain the analytic formula of the point spread function, the integral kernel can be approximated as the Fresnel integral kernel by means of paraxial approximation. Compared to GO, the results from FO are superior due to the inclusion of wave characteristics. Furthermore, we consider scalar wave optics by directly solving the inhomogeneous Helmholtz equation which the scalar light field should satisfy. However, the light field is not assigned to an exact physical meaning in the theory of scalar wave optics, so we reasonably require boundary conditions where the light field function and its first derivative are continuous everywhere on the surface of ball lens. Finally, in the theory of electromagnetic optics (EMO), we consider the polarization of the point source, and the two kinds of Hertz vectors and , both of which satisfy inhomogeneous Helmholtz equation, and are derived from Maxwell¡¦s equations in spherical structures. In contrast with the scalar wave optics, the two Hertz vectors are defined concretely thus allowing us to assign exact boundary conditions on the interface. Then the fields corresponding to and are averaged as the final point spread function.

Increasing evidence suggests that the environment is related to many public health challenges. Unequal distributions of services and resources needed for healthy lifestyles may contribute to increasing levels of health disparity. However, empirical studies are not sufficient to understand the relationship between health disparity and the built environment. This dissertation examines how health disparity are associated with the built environment and if the environmental conditions that support physical activity and healthy diet are associated with lower health disparity. This research uses a multidisciplinary approach, drawing from urban planning, regional economics and public health. The data came from the Behavioral Risk Factor Surveillance System, and the GIS derived environmental data and the 608-respondent survey data from a larger study conducted in urbanized King County, Washington. Health disparity was measured with the Gini-coefficient, and health status and obesity were used as indicators of health. Hot spot analysis was used to identify the spatial aggregations of high health disparity, and multiple regression models identified the environmental correlates of health disparity. The overall trend showed that disparity has increased in most states in the US over the past decade and the southern states showed the highest disparity levels. Strong spatial autocorrelations were found for disparities, indicating that disparity levels are not equally distributed across different geographic areas. From the multivariate analyses estimating disparity levels, spatial regression models significantly improved the overall model fit compared to the ordinary least-square models. Areas with more supportive built environments for physical activity had lower health disparities, including proximity to downtown (+) and access to parks (+), day care centers (+), offices (+), schools (+), theaters (+), big box shopping centers (-), and libraries (-). Overall results showed that the built environment, compared to the personal factors, was more strongly correlated with health disparities. This study brings attention to the problem of health disparity in the US, and provides evidence supporting the existence of spatial disparity in the environmental support for a healthy lifestyle. Further research is needed to better understand environmental and socioeconomic conditions associated with health disparity among more diverse population groups and in different environmental settings.

It is more and more popular to transmit and receive information with Wireless LAN(WLAN) as the time of science and technology has been approaching. Every type of business gradually has priority on WLAN for marketing. Especially business of agents of real estate, they use WLAN as tool for marketing to improve the service with information and human nature and to break through the shape of traditional human operation. They record characters and functions of surrounding environment of the houses which are entrusted by clients in their system to provide immediate and local information with house-buyer. This becomes personalizing and valuable selling information. It takes both quantitative and qualitative methods as research methods in the study, and agents of real estate using and not using WLAN in Kaohsiung City are picked as research objects. The study takes depth interviews to realize conditions for wireless network marketing using, motivation for wireless network marketing, and using mode for wireless network marketing, and it also analyzes the differences among wireless network marketing, traditional marketing, and internet marketing. Meanwhile the study use questionnaires survey to figure out the reason why some agents of real estate do not use WLAN for marketing. There are four findings in the study as follows: (1) Agents of real estate using WLAN for marketing are mainly direct branches and over 15 years old. (2) The traditional way for marketing used by agents of real estate using or not using WLAN for marketing is newspaper. (3) Agents of real estate using WLAN for marketing know the requirements of clients and can improve the quality of service better then agents of real estate not using WLAN for marketing. (4) The rate of agents of real estate not using WLAN for marketing at present would like to use WLAN for marketing in the future become more. The conclusion of the study indicates the marketing mode of using new science technology can inquire new information anytime and anywhere. The mode of marketing with WLAN provides business of agents of real estate with the immediate and local information, and this is the point that mass media can not achieve. There are difficulties for business of agents of real estate in Kaohsiung City to use high science technology as a kind of marketing mode. Kaohsiung City should try to upgrade M capacity step by step and take both traditional marketing and WLAN marketing to enhance the function of WLAN for marketing in business of agents of real estate.

With the liberalization of financial market, the prevalence of international trade and the prosperity of foreign exchange markets ,investors could hedge,speculate or interest arbitrage in markets. Therefore, market efficiency is worthy of investigation and analysis on the international finance extensively. According to simple market efficiency hypothesis, there would be a long-run relationship between spot exchange rate and forward exchange rate if the foreign exchange market is efficient. Under the circumstance, this study firstly tries to examine whether there is a long-run relationship or not between spot exchange rate and forward exchange rate by Linear Cointegration Theory. At the same time, the study tests Simple Market Efficiency Hypothesis is correct or not in practice. Next,in a non-linear threshold cointegrational way, it looks into whether there is an apparent threshold effect or not among variables, and the adjusting behavior in the long-run equilibrium process. The result of the study proves that there are an apparent threshold effect and inconsistent behaviors in the long-run equilibrium process.

In this thesis, the effects of Harmonics on the Top Oil and Hot Spot Temperatures of Power Transformers used in Turkish Electricity Transmission System have been investigated. Due to the solid state equipment, the harmonic levels increase. This effect raises the losses and temperatures in the transformer windings. None of the power transformers currently used in Turkey has measuring equipment suitable for measuring the Hot-Spot temperatures. In this study, a computer program is written in LABVIEW which measures the harmonics and calculates the temperatures in accordance with the methods recommended in IEEE Standards C57.110-1998 and C57.91-1995. Also for sample transformers the work has been verified by measuring the Top-Oil temperatures of the transformers and then comparing with the calculated results.

This study establishes pedestrian safety focused environment around elementary schools. In order to reach this objective 3 consecutive goals are fulfilled / firstly / proposing, a newly designed black spot analysis, &ldquo / Behavioral Black Spot Analysis&rdquo / , secondly / documenting pedestrian behavior around black spots, and finally stimulating effective interventions around elementary schools. This study proposes a newly designed methodology / &ldquo / Behavioral Black Spot Analysis&rdquo / which is namely based upon pedestrians&rsquo / route choice and risk perception statements. Additionally it is observed that students choose the shortest route on their way. &ldquo / Behavioral Black Spot Analysis&rdquo / reveals that traffic flows, pedestrian visibility, vehicle visibility, waiting time, road width are most important parameters of pedestrians&rsquo / perception of traffic safety. Results of unobtrusive observations indicate that interventions have significant effect on vehicle speed, number of conflicts, yielding behavior of drivers, total number of cars forming a queue, number of pedestrians stopping on the curb, head movements, crossing angles, crossing tempos, and crossing distances of pedestrians. Behind this interventions affects pedestrians&rsquo / waiting time in negative manner. Recommendations for pedestrian safety interventions are suggested.

The purpose of this study is to integrate the efficiency of the computer-aided design software Pro Engineer and the finite element analysis software LS-DYNA on the structural design of the golf club head. By means of the parametric design characteristics of Pro Engineer, various thickness and different shapes of the golf club head have been studied. The impact model will extract the ball velocities and spins for a given hit location on the club face which is analyzed by the software LS-DYNA. After that, the factors for influencing the dynamic analysis, such as the thickness and the shape of the hitting face, the off-center hitting, the ball velocity and spin, the stress distribution, and stress propagation in the head are further identified and measured. Finally, the effects of the factors described above have been analyzed quantitatively to investigate the maximum velocity of the ball and the sweet spot of the golf club head.

ABSTRACT The substance of this study is to analyze the impact process between golf club head and golf ball by integrating the capability of the CAD software I-DEAS and the finite element analysis software LS-DYNA. The various golf club head can be created much easily by determined the dimension parameter in the variable-parameter characteristics of I-DEAS. The computational cost can be reduced by explicit central difference method of LS-DYNA. This study is to analyze the impact effect of varied thickness based on Taguchi method of experimentation and off-center hit in difference volume club head. After that, the hitting area, the sweet spot of club head and influencing factors of impact effect are discussed. It is expected that the findings of the study may provide engineers with some effective method to deal with golf club head design.