• Proceedings of the Korea Society of Design Studies Conference
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• 2005.05a
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• pp.104-105
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• 2005

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.04a
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• pp.327-331
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• 2001

In the process of optical parts machining, polishing has been applied. Traditional polishing process is suitable for spherical optical parts. But it is very difficult to apply traditional process for aspheric optical parts. Nowadays, as growing needs for aspherical optic parts, many researches have been conducted. In this study, we developed computer controlled polishing system which consists of three major parts of active pressure control for correcting polishing process, mechanical on-machine measurement for rough polishing, and optical on-machine measurement for finish polishing, respectively. In this paper, a systematic stretegy for correcting polishing process, pressure control scheme for polishing tool, and on-machine measurement methods for automated and precise polishing are suggested. The information about developed machine is also included.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.819-821
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• 2003

본 논문에서는 압전 트랜스듀서의 임피던스 해석을 유한 요소법을 통해 실험적으로 검증하였고, 이러한 유한 요소법을 이용하여 압전 변압기의 동작 주파수 및 등가회로 정수를 도출하였다. 또한, 등가 회로법을 이용하여 부하 변동에 따른 압전 변압기의 공진 주파수와 효율 변화를 분석하고 이를 실험적으로 검증하였다. 한편, 유한 요소법과 자동 요소 분할 프로그램(Auto-Mesh Generator), 최적화 알고리즘을 이용하여 일정 부하에서 최대 효율을 갖는 압전 변압기의 형상 최적화를 수행하였는데, 최적화 기법으로는 sinc 함수의 수렴 결과를 통해 타당성이 입증된 진화 알고리즘 (Evolution Strategy)을 적용하였다.

• Korean Journal of Applied Biomechanics
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• v.15 no.1
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• pp.45-61
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• 2005

Stance is defined as any state in which the total mass of the body is supported by the feet. In order to maintain stance, the sum of gravito-inertial forces acting on the body must be registered by equal and opposite forces at the region of contact between the organism and the support surface. Balance is controlled by applying forces to the surface of support so as to maintain the body's center of mass vertically above the feet. for a muIti-segment organism, there can be a variety of ways in which balance can be controlled, since movements of different body segments can have similar effects on the control of balance. In general, the organism tends to have a body configuration that is aligned with gravito-inertial force when there are no external forces acting on it. If any segments of the body are not aligned with gravito-inertial force vector, a torque on that segment would tend to move the body's center of mass. The maintenance of postural stability is accomplished in humans by a complex neural control system. This requires organizing integrating and acting upon visual, vestibular, and somatosensory input, providing orientation information to the postural control system. The information necessary to control and coordinate movement is provided by the visual sense of eye position with respect to the surrounding surface layout, the vestibular sense of head orientation in the gravito-inertial space, and the somatic sense of body segment position relative to one another and to the support surface. In this study, perception and action capability was examined from various points of view. The underlying assumption of the study was that the change of postural configuration could be effected by organism, environment and task goal.

• The Journal of Korean Academic Society of Nursing Education
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• v.4 no.2
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• pp.159-171
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• 1998

The purpose of this study is to explore the relationships between hope, health locus of control and general health of nursing students. The subjects of this study were 161 female students of National Nursing School in Seoul. Data was collected through a questionnaire from May 11 to May 23, 1998. The tools used for this study were Hope scale developed by Miller and Power, Multidimensional Health Locus of Control Scale developed by Wallston and Wallston and General Health Scale(Modified Conel Medical Index) developed by Nam Ho Chang. Data were analysed in an the $SPSS/pc^+$ program using frequency for the demographic characteristics, 1-test and ANOVA for relationship between the variables and demographic characteristics and for it's differences of hope and general health control. Peason correlation coefficient for relationship between the 3 variables, hope, health locus of control, and general health. The results of this study were as follows ; The 1st hypothesis : that 'Between hope, health locus of control (HLC) and general health of nursing students will have positive relationship', was supported(=.2883, p=.000). The 2nd hypothesis; that 'The hope score of nursing students in HLC-internal group will be higher than others' was supported(F=5.22, p=.0063). The 3rd hypothesis ; that 'The general health of nursing students in HLC -internal group will be higher than others' was accepted(F=2.94, p=.0554). The 4th hypothesis ; that 'Hope, HLC and general health of nursing students according to demographic characteristics will be different ' was accepted in part. o In hope the more age, the higher score. o In HLC the group of non religious have higher score(t=-2.02, p=.045). o No experienced addmission was revealed HLC-internal group(t=-1.91, p=.058). o Non religious group has a tendency to dependent upon on powerful other person(t=-1.99, p=.049). o The hope score of nursing students was very high(4.49/6point). o The general health status of nursing students was vert good(92.88/114point). o Most of nursing students was in HLC-internal group(81.4%). o The most frequent complaints of nursing students was dizziness suddenly developed(68.4/114point), very nervous in small thing(67.83/114) and very nervous to others critics(68.4/114) in turn. In conclusion, the students who have high score of hope, in HLC-internal group have good general health. Hope inspiring not only makes one's good health but also makes others good health and powering hope. For good health person who are in HLC-internal group have powerful hope, keeping good health would be a good stretegy to change the student's HLC and make them good health and hope powering then it would be a good method to change the HLC to HLC-internal group.