• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 춘계학술대회논문집
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• pp.490-495
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• 2001

This paper deals with an analysis and countermeasure for improving the shock performance of laptop computers. The shock analysis is carried out by using the commercial program of LS-DYNA3D. Also the analysis is verified by the measurements from modal tests and shock tests. The available countermeasures are investigated theoretically and experimentally to find the effective methods of reducing the shock acceleration on hard disk driver during one side fall test. The hard disk drive is the most sensitive part in a laptop computer. This research shows the effects of the spring constant of rubber pad, the reinforcement of mechanical parts and the location of a hard disk driver, on the shock reduction.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 춘계학술대회논문집
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• pp.569-574
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• 2008

Nowadays, the equipment for a semiconductor process is required to raise accuracy and productivity. Therefore, the natural frequency of the equipment has been lowered because it has been precise, rapid, large, and light. In order to improve the efficiency of production, it is necessary for the equipment to increase the operation speed, which causes inevitable vibration problems. In this paper, influence analysis of ball-screw in the equipment and evaluation method for the vibration on the base are presented based on the analyses of dynamic characteristics for the mechanical structure through the modal test.

• 한국식품조리과학회지
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• 제8권1호
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• pp.43-47
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• 1992

This study attempted to examine the effects on sensory characteristics, texture and color of steamed soybean rice cake in various levels of soybeans. Sensory evaluation was done by panels of 7 judges. Objective measurements were made by utilizing the Instron and Hunter Colormeter. The results were as follows; 1. The content of moisture, total ash, protein, fat and carbohydrate in rice were shown to be about 13.47%, 0.48%, 6.40%, 0.54% and 79.11%. Those of soybean were 10.95%, 4.54%, 30.67%, 20.36% and 33.48%. 2. The results of sensory evaluation revealed that rice cake containg 20% of soybean produced the best quality in most sensory characteristics. 3. By Instron measurement of various levels of soybean in steamed soybean rice cake, hardness and cohesiveness were not different. By color value of that, b value was tend to increase as the addition level of soybean.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.688-693
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• 2002

Identification method is formulated to evaluate the dynamic characteristics of air bearings under NFR(Near Field Recording) sliders. Impulse responses and frequency response functions of NFR sliders are obtained on numerical non-linear models including rigid motion of slider and fluid motion of air bearing under the slider. Modal parameters and system parameters are identified by modal analysis method and instrumental variable method. The parameters of sliders are utilized to evaluate the dynamic characteristics of air bearings. Also, this study shows the difference between the dynamic characteristics of NFR and HDD slides, and squeeze effect of air bearings.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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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.

• 한국실내디자인학회논문집
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• 제32호
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• pp.28-35
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• 2002

After 18th century in Korea, a tendency of the traditional folk houses shows not only the typical types but also the cultural areas in terms of each regional part. The existing folk houses are selected in order to compare the characteristic of the plans with those of the central region in Korea. Moreover this region has been a collided zone of culture and military from the old period of the Three Kingdoms, because the district of Che-chun is located between the southern part and the central one. So its culture and housing plan showed as unique forms, so-called the Culture of Frontier and Composite. Consequently the purposes of this study are to grasp the characteristic of those plans and to compare the plan types with ones of the central region. For the attainment of the above goal, this investigated study is prosecuted by means of the existing 6-folk houses in Che-chun city.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 II
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• pp.586-591
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• 2001

Dynamic analysis using impulse responses is formulated to estimate effect of slider rail shape on dynamic responses. Impulse responses are obtained on numerical nonlinear model including rigid motion of slider and fluid motion of air bearing under the slider. Dynamic characteristics of slider motion are evaluated by utilizing the decay ratio of impulse responses and modal frequencies from frequency response functions. The dynamic characteristics of the developed NFR(Near Field Recording) slider are checked by comparing those of HDD sider(Nutcracker). Also, sensitivities of slider position conditions and rotation speed on the dynamic characteristics are investigated. The researches show that the utilized method is a good indicator of designing the better slider.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 추계학술대회논문집
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• pp.737-741
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• 2000

Portable communication devices such as laptop computers suffer impact-induced failure in their usage. Drop/impact performance of these products is one of important concerns of product design. Because of the small size of this kind of electronics products, it is very expensive, time-consuming and difficult to conduct drop tests to directly detect the failure mechanism and identify their drop behaviors. Finite element analysis provides a vital, powerful vehicle to solve the problems. The models are created with HYPERMESH, and the analysis is carried out with LS-DYNA3D. The analysis is focused on HDD impact behavior in acceleration peak values.

• Ecology and Resilient Infrastructure
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• 제9권2호
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• pp.130-130
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• 2022

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2023년도 춘계학술발표대회
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• pp.536-538
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• 2023

수출의존도가 높은 한국은 코로나19 팬데믹, 우크라이나-러시아 전쟁 등 대외환경의 변화에 따른 수출 여건에 민감할 수 밖에 없는 환경이다. 이에 발 빠르게 대응하기 위해 정확한 수출증감률 예측이 필요하며 이를 가장 잘 수행할 수 있는 예측모델을 찾고자 한다. 수출에 영향을 끼치는 주요변수 선정 후, min-max 정규화를 시행하고 변수간 상관계수와 다중공선성 확인을 통해 변수를 축소했다. 그리고 머신러닝 예측모델로 많이 사용되는 Linear Regression, Decision Tree, Gradient Boost Regressor, Random Forest 4가지 모델에 대입하여 수출 증감률 예측 정확도를 비교했다. 그 결과, Linear Regression의 MSE가 0.087로 가장 낮아 제일 우수한 모델이라는 결론에 도달했다.