• 대한전기학회논문지:시스템및제어부문D
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• 제54권1호
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• pp.33-39
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• 2005

In this paper, we propose a slider servo-mechanism driven by electro-magnetic actuator to improve straightness of linear motor stages. Based on axial-position dependent deterministic characteristics of the straightness error, a feedforward compensation control is appled to reduce the straightness error. In the consideration of uncertain properties of friction and its effects on positioning accuracy, a sliding mode control is applied. The effectiveness of the suggested mechanism and the control performances are illustrated along with some experimental results.

• 한국반도체및디스플레이장비학회:학술대회논문집
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• 한국반도체및디스플레이장비학회 2007년도 춘계학술대회
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• pp.11-14
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• 2007

An additive servo-system is developed to improve straightness of linear motor stages. For linear motor stages used in the field of high-precision linear motion process, high straightness accuracy is necessary as well as positioning accuracy in the longitudinal axis. In such cases, machining and assembling cost increases to improve the straightness accuracy. An electro-magnetic actuator which is relatively cost effective than any other conventional servo-systems is suggested to compensate the fixed straightness error. To overcome the compensation error due to modeling error and friction disturbance, a sliding mode control is addressed. The effectiveness of the suggested mechanism and the control are illustrated along with some experimental results.

• 기술경영경제학회:학술대회논문집
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• 기술경영경제학회 2000년도 제17회 하계학술발표회 논문집
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• pp.105-120
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• 2000

Rapid spread of Internet, there appear so many commercial wedsites. Websites are not only tools to advertise a company or a product, but also value-added products inself. So we need a systematic approach(planning, design, implementation) to develop a website. But existing reserches on website development have corvered only technological issues such as network and HCI(Human Computer Intercation). In this research a framework is proposed to develop a website systematically using database of existing websites. This framework is composed of several stages-target customer segmentation, determination of services on website, dtermination of business model, functinal positioning, and evaution.

• 한국해양공학회지
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• 제25권4호
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• pp.1-6
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• 2011

The installation of a topside structure can be categorized into the following stages: start, pre-lifting, lifting, lifted, rotating, positioning, lowering, mating, and end of installation. The transfer of the module onto the floating spar hull occurs in the last three stages, from lowering to the end. The coupled multi-body motions are calculated in both calm water and in irregular waves with a significant wave height (1.52m). The effects of the hydrodynamic interactions between the heavy lifting vessel and the spar hull during the lowering and mating stages are considered. The internal forces caused by the load transfer and ballasting are derived for the mating phases. The results of the internal forces for the calm water condition are compared with those in the irregular sea condition. Although the effect of the pitch motion on the relative vertical motion between the deck of the floating structure and the topside module is significant in the mating phases, the internal force induced pitch motion is too small to have this influence. However, the effect of the internal force on the wave-induced heave responses in the mating phases is noticeable in the irregular sea condition because transfer mass-induced draught changes for the floating structure are observed to have higher amplitudes than the external force induced responses. The impacts of the module on the spar hull in the mating phase are investigated.

• 한국해양공학회지
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• 제25권4호
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• pp.7-11
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• 2011

The installation phase for a topside module suggested can be divided into 9 stages, which include start, pre-lifting, lifting, lifted, rotating, positioning, lowering, mating, and end of installation. The transfer of the topside module from a transport barge to a crane vessel takes place in the first three stages, from start to lifting, while the transfer of the module onto a floating spar hull occurs in the last three stages, from lowering to the end. The coupled multi-body motions are calculated in both calm water and in irregular waves with significant wave height (1.52m), with suggested force equilibrium diagrams. The effects of the hydrodynamic interactions between the crane vessel and barge during the lifting stage have been considered. The internal forces caused by the load transfer and ballasting are derived for the lifting phases. The results of these internal forces for the calm water condition are compared with those in the irregular sea condition. Although the effect of pitch motion on the relative vertical motion between the deck of the floating structure and the topside module is significant in the lifting phases, the internal force induced pitch motion is too small to show its influence. However, the effect of the internal force on the wave-induced heave responses in the lifting phases is noticeable in the irregular sea condition because the transfer mass-induced draught changes in the floating structure are observed to have higher amplitudes than the external force induced responses.

• International Journal of Naval Architecture and Ocean Engineering
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• 제5권3호
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• pp.431-453
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• 2013

The principal purpose of this paper is to present a novel two phases rational scenario applied in constructing an offshore monopod platform; in which the two phases are the all-ground horizontal construction phase and the post-construction phase. Concerning the all-ground construction phase, a brief investigation of its different stages, i.e., pre-fabrication, fabrication, pre-assembling, positioning, assembling, and surface finishing is introduced. The important practical aspects of such construction phase are investigated without going into the nitty-gritty of the details involved therein. Concerning the post-construction phase, a clear investigation of its sequential stages, i.e., lifting, moving and up-righting is introduced. A finite element model (FEM) of the monopod platform is created to perform the structural analysis necessary to decide the suspension points/devices and the handling scenario during the various stages of the post-construction phase on a rational wise. Such structural analysis is performed within the framework of the three dimensional quasi-static modeling and analysis aiming at simulating the realistic handling condition, and hence introducing a reliable physical interpretation of the numerical results. For the whole effort to be demonstrated efficiently, the results obtained are analyzed, the conclusions are presented, and few related recommendations are suggested.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2002년도 Proceedings
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• pp.324-327
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• 2002

For a next generation PET that realizes high sensitivity and high resolution, we proposed a design of a depth of interaction detector. A unit of the detector is constructed of four stages rectangular blocks of 2 by 2 Gd$_2$SiO$\sub$5/: Ce (GSO) crystal array optically coupled to position sensitive photomultiplier tube (PS-PMT). The 256ch flat panel PS-PMT is under development by Hamamatsu Photonics K.K., JAPAN. It has large cathode area, 51.7 by 51.7 mm$^2$, and the ratio of the effective area to external size is about 90%. The feature will contribute high packing fraction, accordingly high sensitivity. The 256 anodes are arranged in 16 by 16 at intervals of 3.0 mm. So as to evaluate the detector capability for identifying crystal of interaction, we got positioning image histograms with coupling a 16 by 5 array of GSO crystals, 2.9 by 2.9 by 7.5 mm$^3$, to the PS-PMT by irradiating a gamma ray uniformly from a point source. Flat panel PS-PMT is a new promising device for PET. We need to evaluate it if its performance is sufficiency. The performance was compared to the one with a 16ch PS-PMT.

• 한국정밀공학회지
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• 제25권12호
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• pp.132-138
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• 2008

Recently, mastering processes for high density optical disc such as Blu-ray disc rely on electron beams, which are operable in only vacuum. In the mastering process, one of the most important tasks is to design precision stages for providing precise positioning of the works with respect to the source in a high vacuum environment. In this paper, we have developed a precision rotation table usable in the electron beam mastering. The rotation table adopted air bearings for a high positioning repeatability and velocity stability. The air leakage from the air bearings has been minimized by employing the differential exhaust scheme using three steps of air drain. The design parameters such as diameters of exhaust lines, seal lengths, and pumping speeds were decided according to the optimization method using genetic algorithm. The performance on the vacuum level of the rotation table was evaluated experimentally and theoretically. The results indicate that a vacuum level of $10^{-4}$ Pa is achieved with operation of air bearings in a vacuum chamber, which is sufficient for the electron beam mastering.

• 한국지역지리학회지
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• 제11권5호
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• pp.405-425
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• 2005

대중관광에서 신관광으로의 전환은 문화관광의 다기한 발전과 밀접하게 연결되어 있다. 본 연구에서는 문화관광지의 생성 개발 및 진화 발전 단계를 도출하여 '문화관광개발의 개념적 모형'을 구축하고자 한다. 또 관광, 문화예술 활동, 문화제품 생산 간에 유기적인 시스템이 존재하고 있음을 개념적으로 밝히고 있다. 연구 결과 문화관광지는 '장소 이미지 형성', '상징적 공간 구축', '문화적 활동의 영역적 시스템 형성' 등 세 단계를 거치면서 진화 발전한다. 또 각단계별로 존재하는 몇 가지 지배적인 구성요소를 도출함으로써 문화관광지의 발전 매커니즘을 보다 구체적으로 이해할 수 있게 되었다. 이 연구는 통합적, 영역적 관점에서 관광현상을 분석함으로써, 관광부문과 지역 사회경제 각 부문간 관계를 이해하고, 활력 있는 시스템적 관계로 전환하는 방법론 개발에 기여한다. 이 연구는 장소성, 장소이미지, 활동공간, 영역적 시스템 및 네트워크 등 인문지리학적 이론과 개념에 크게 의존하고 있다.

• 대한간호학회지
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• 제32권6호
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• pp.832-843
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• 2002

The aim of this study was to describe women's embarrassability and embarrassment during cervical screening. Method: The subjects of this study were 82 women who had a cervical screening at a National University Hospital. The data were collected through personal interview using a questionnaire from February 4, 2001 to February 22, 2002. The questionnaire consisted of embarrassability scale, embarrassment Scale, and demographic data. Result: 1) The mean scores of situational embarrassability was 82.6 and that of dispositional embarrassability was 106.7. 2) The mean scores of subject's embarrassment was 54.3 and 48.7 in 10 stages of cervical screening. The following three situations of 10 stages of cervical screening were highly ranked as to be embarrassing: 'during the examination', 'waiting for a doctor', and 'climbing up the exam chair and positioning her thigh for a exam'. 3) There was a positive correlation between dispositional embarrassability and embarrassment of 10 stages of cervical screening. 4) There were significant differences in situational embarrassability of subjects according to education and the locations of service. There were significant differences in dispositional embarrassability of subjects with regard to frequencies of pregnancy. 5) There were significant differences in embarrassment of subjects during cervical screening with respect to age, age at the time of first smear and gender of the examiner. Conclusion: The finding of this study indicates that women experienced a high level of embarrassment during cervical screening, assuming a need for nursing intervention reduces women's embarrassment. Also, there is a positive correlation between embarrassability and embarrassment of cervical screening, suggesting a need for further research identifying the effect of nursing intervention on embarrassment according to embarrassability.