• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.831-836
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• 2006

In the process of accurate manufacture and measurement, it is necessarily required to isolate external or internal vibration due to external disturbance and internal actuators. The higher vibration isolation system gets damping around resonance, the better it is generally. This paper analyzes the performance of an existing passive air-spring for vibration isolation table by using experiment and simulation. Optimal design for a passive air spring can be obtained by tuning the size of the orifice. Also design for an active isolation system is carried out by applying PID controller and considering non-linearity of pneumatic characteristics with help of look-up table. We have developed the active vibration isolation table with the better isolation performance.

• Proceedings of the Korean Society of Crop Science Conference
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• 2006.04a
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• pp.430-431
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• 2006

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.909-914
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• 2006

Vibration isolation tables are mostly required in precise measurement and manufacturing system. Among the vibration isolation tables, an air spring is the most favorable equipment because of low resonant frequency and high damping ratio. However, it is difficult to design the air spring with the required stiffness and damping ratio. Futhermore, whenever conventional active control methods are applied to the air spring, it may be difficult to obtain effective control performance due to high nonlinearity of air spring. In this paper, the optimal design of the air spring is performed using genetic algorithm to bring out low resonant frequency and high damping ratio. Also, active control of the vibration isolation table with 3-DOF model is proposed using the adaptive control method. Through experiments, optimal design is shown to be effective. And performance of the proposed control method is verified to be better than those of the passive control method and the conventional active control methods.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1993.04a
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• pp.40-45
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• 1993

일반적으로 건물 구조물에 전달되는 기계진동을 감소시키기 위해서 기계와 기초사이에 유연한 방진소자를 삽입하여 기계가진력(exciting force)의 전달 률을 줄인다. 또한 구조물의 고유진동수와 진동원의 가진주파수가 일치할 경 우, 가진주파수를 변화시키거나, 구조물의 동특성을 변화시키는 방법을 사용 한다. 어떠한 방안을 선택하든 효과적이고 정량적인 방진 시스템을 구성하고 구조물의 정확한 진동상태를 예측하기 위해서는 진동원의 가진특성과 구조 물의 동특성에 대한 정보가 요구된다. 일반적으로 방진설계를 위해 필요한 진동원의 가진특성은 제조회사의 사양이나 측정을 통하여 비교적 쉽게 얻을 수 있다. 복합재료, 다양한 경계조건, 복잡한 대형구조물등은 수치해석을 이 용하여 해석적인 방법으로 동특성을 구할 경우, 신뢰성 있는 정보를 얻기에 는 많은 노력이 요구된다. 더우기 현장에서 발생하는 진동문제는 대부분 복 잡하고 시간적으로 시급히 해결해야 하기 때문에 효율적인 절차를 구성하여 구조물의 동특성을 해석하는 방법을 사용할 필요가 있다. 구조물의 동특성은 실험적인 방법을 통하여 구하고 그 외의 필요한 계산들은 해석을 통하여 얻 는 것이 효율적일 수 있다. 실험적 동특성해석은 입력하중에 대한 응답의 크 기와 위상 비를 주파수별로 나타내는 전달함수를 측정하는 방법으로서 가진 장치 및 여러 측정/분석 장비가 필요하며, 철교, 교량, 건물의 철골 및 콘크 리트 슬라브등 다양한 중대형의 구조물을 Signal/Noise비가 좋도록 가진 시 켜야 할 필요성이 있다. 본 연구에서는 이러한 실험적 방법의 현장 적응성과 신뢰성을 확보하기 위해 대형충격기(large impact hammer, max, peak force 약 10000N, time duration 약 20ms)를 제작하고 실험/분석 시스템 및 구조물 의 진동제어를 위한 절차를 Fig.1과 같이 구성하고 이를 철근콘크리트 건물 에 설치한 기계식 주차설비의 진동제어에 적용하였다.force response simulation)를 수행하여 임의의 좌표 공간에 대한 진동수준을 해석적으로 예측할 뿐만 아니라 구조물의 진동제어 를 위한 동적인자를 변경시킬 수 있는 정보를 제공하며 장비를 방진할 경우 신뢰성 있는 전달률을 결정할 수 있다. 실험적으로 철교, 교량이나 건물의 철골구조 및 2층 바닥 등 대,중형의 복잡한 구조물에 대항 동특성을 나타내 는 모빌리티를 결정할 경우 충격 가진 실험이 사용되는 실험장비 측면에서 나 실험을 수행하는 과정이 대체적으로 간편하다. 그러나 이 경우 대상 구조 물을 충분히 가진시킬수 있는 용량의 대형 충격기(large impact hammer)가 필요하게 된다. 이러한 동적실험은 약 길이 61m, 폭 16m의 4경간 교량에 대 하여 동적실험을 수행하여 가능성을 확인하였다. 여기서는 실험실 수준의 평 판모델을 제작하고 실제 현장에서 이루어질 수 있는 진동제어 구조물에 대 한 동적실험 및 FRS를 수행하는 과정과 동일하게 따름으로써 실제 발생할 수 있는 오차나 error를 실험실내의 차원에서 파악하여 진동원을 있는 구조 물에 대한 진동제어기술을 보유하고자 한다. 이용한 해마의 부피측정은 해마경화증 환자의 진단에 있어 육안적인 MR 진단이 어려운 제한된 경우에만 실제적 도움을 줄 수 있는 보조적인 방법으로 생각된다.ofile whereas relaxivity at high field is not affected by τS. On the other hand, the change in τV does not affect low field profile but strongly in fluences on both inflection fie이 and the maximum relaxivity value. The results shows a fluences on both inflection field and the maximum relaxivity value. The results shows

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2006.10a
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• pp.184-189
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• 2006

In the process of accurate manufacture and measurement, it is necessarily required to isolate external or internal vibration due to external disturbance and internal actuators. The higher vibration isolation system gets damping around resonance, the better it is generally. This paper analyzes the performance of an existing passive air-spring for vibration isolation table by rising experiment and simulation. Optimal design for a passive air spring can be obtained by fluting the size of the orifice. Also design for an active isolation system is carried out by applying PID controller and considering non-linearity of pneumatic characteristics with help of look-up table. We have developed the act ive vibration isolation table wi th the bet ter isolation performance.

• KSBB Journal
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• v.19 no.2
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• pp.113-117
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• 2004

The effect of ultrasonification on immuno-stimulatory activities of the extracts from Ephedra sinica Stapf and Rubus coreanus Miq. was observed by the growth of human immune cells. The extraction yields from water extracts and water extract with ultrasonification at 40$^{\circ}C$, 60$^{\circ}C$ and 100$^{\circ}C$ were compared. The highest yield was observed enhancement ratio 2.34% in the extract at 40$^{\circ}C$ with ultrasonification. The growth of human T-cell was increased up to 13.8${\times}$10$^4$ viable cells/$m\ell$ in adding 1.0 g/L of the ultrasonification extracts. The treated extracts increased the specific secretion of TNF-${\alpha}$ up to 10.5${\times}$10$\^$-4/ pg/cell. It was suggested that of the extracts on water the extraction yield with ultrasonification compared improved the extraction with ultrasonification of low than.

• Korean Journal of Medicinal Crop Science
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• v.12 no.4
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• pp.273-278
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• 2004

The anticancer activities of the extracts from Acanthopanax senticosus Harms, Ephedra sinica Stapf, Rubus coreanus Miq and Artemisia capillaris Thunb were compared according to extract systems. About 70% of the growth of human hepatocarcinoma cancer cell was inhibited in adding 1.0 mg/ml of the water extract from Rubus coreanus Miq with ultrasonification at $60^{\circ}C$. The growth of human normal lung cell was limited to 25% in adding the extracts with ultrasonification at $60^{\circ}C$. The effect of extracts obtained by only water and with ultrasonification on different of human promyelocytic leukemia cells was also observed.

• Fire Science and Engineering
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• v.26 no.5
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• pp.41-47
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• 2012

As a core process in the manufacture of state-of-the-art industrial technologies such as semiconductor and LCD, a clean room is the most important process which can affect the performance and quality of products drastically. Nevertheless, scientific research on comprehensive safety measures from a fire protection standpoint is not being carried out in Korea. This study aims to derive measures to improve smoke control systems by identifying performance and problems of smoke systems installed in clean rooms as an LCD manufacturing process and analyzing fire and evacuation simulations considering several scenarios. As a result of analysis of fires and smoke in a clean roomas an LCD manufacturing process, it is found to be necessary to stop air handling units through interlocking in case of a fire and exhaust smoke out of the room through the top of FAB in consideration of buoyancy of smoke. It is also found to be necessary to install quick response sprinkler heads and accessories to accelerate the response time, because the heat-accumulating performance of sprinkler heads decreases in this application. Despite its low density of dwelling due to the automation process, clean room is characterized by an array of complex production equipment and working environment requiring dustproof clothes, which makes it difficult to acquire evacuation safety performance. Thus, thorough control of danger factors in processes and periodic education and training are required. It is also necessary to establish a level of domestic technologies equivalent to the level of standards of advanced countries in fire protection.

• Korean Journal of Human Ecology
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• v.6 no.2
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• pp.121-131
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• 1997

This study was to design the clean room garment which fits for a body and adjusts well to the action. We examined the body's changes in action through a body measurment and made a sample of the clean room garment to which had adapted the body's changes in action and evaluated the function and the appearance compared with the existing the clean room garment. The followings were summery of the results : 1. Back intersyce breadth decreased, trunk length increased and the other parts were not change. At a posture of raising hands($M_3$) in comparison with an upright posture($M_0$). Back intersyce breadth, hip length and knee length increased and the other parts were a little change. At a bowing posture($M_2$) in comparison with an upright posture($M_0$). Back hip girth, knee length, hip length and leg length increased and the other parts were not change. At a working posture on a chair($M_1$) in comparison with an upright posture($M_0$). 2. The overall clean room garment was made increasing on the changes of part of a body through measuring and body measurement. 3. From the test of the function, it became known that the devised clean room garment was superior to the existing one in the parts of neck, shoulder, armpit and elbow at a working posture on a chair($M_1$), in the parts of neck, shoulder, and armpit at a bowing posture($M_2$), and the armpit at a posture of raising hands($M_3$). The appearance was better on the whole. 4. From the examination of photographs, the waist line of the devised clean room garment was not so much pulled up as that of the existing one on moving. And when sitting down on a chair, the waist line of the existing one was pulled down while that of the devised one had no change. As above, we investigated the actual conditions of wearing the clean room garment and measured the body's changes according the various actions. So we applied these results to the devised clean room garment but we couldn't research the clean mom effect of it owing to not obtaining the measuring instrument. The aspect of ergonomics liked the feeling of wearing and fitted to the action must be given consideration to the clean room garment, and simultaneously the dust-resistant effect must be taken into consideration in order to improve the quality of the goods. Therefore, we think it should be continued the research on the dust-resistant effect, material, washing method, quality control, and size along with the aspect of ergonomics.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1998.04a
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• pp.255-263
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• 1998

Dust-free garment prevents contamination which otherwise is caused by skin and clothes to protect from dust or dirt. Therefore, it requires high performance and should function as a working clothes. Clothes are a medium between human and thermal environmental system, and it is required to study human enviroment to ensure comfortableness of clothes and to satisfactorily go along with enviroment .This study investigates the physical and physiological features of dust-free garment used in the clean room at a semiconductor factory in oredr to scientifically clarify what the dust-free garmint is as well as to contribute to the design and development of high performance material and clothes. Three kinds of dust-free fabrics (DFG-I, DFG-II, DFG-III) which are being developed by a local company are used to manufacture dust-free garment. These dust-free garments are dressed and tested in such an enviroment as similar to semiconmemts with temperature at 23${\pm}$1$^{\circ}C$ and humidity at 50${\pm}$5%RH in order to investigate the thermo physiological and psychological features of human body. The results of this study are as follows. The results of this study are as follows. 1.The mean skin temperature was significantly different among the clothes, subjects and experimental time. Temperature tends to rise from the time of exercising load. Continuous motion coupled sealed clothes prevents heat transmittance, and temperature rises in the order of DFG-l, DFG-ll and DFG-lll as time course. 2.As for the skin temperature by local timperature is minimun on the head and torso and increares remarkably at the terminal part of human body. 3. As for the body mass loss was significantly higher in DFG-lll than DFG-l and DFG-ll. 4. Though there is no significant difference in the temperature within clothes among the kind of clothes temperature is 1$^{\circ}C$ higher in the back. Temperature within all the dust-free garments 29.7$^{\circ}C$ in the back and 31.3$^{\circ}C$ in the chest which belong to the comfort zone(31-33$^{\circ}C$). The relative humidity is 39.7%RH in the chest and 33.8%RH in the back which is slightly below the comfort zone(40-60%RH) 5. The thermal sensation belong to the comfort zone regardless of the kinds of clothes. The subjects feels a slight fatigue as times goes. As for the subjective sense of subjects the mean skin temperature as well as temperature and humidity within clothes show similar tendency. This means that they relate with each other.