• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.717-718
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• 2015

전동기를 설계 시 자기등가회로법은 전동기의 세부 형상에 크게 구애를 받지 않기 때문에, 공간고조파법과 수치해석기법에 비해 유용하다. 이 논문에서는 Spoke type PMSM(Permanent Magnet Synchronous Motor)의 회전자 자기등가회로를 설계하였다. 회전자 자기등가회로를 통해, 마그네틱 토크 성분을 구성하는 공극자속밀도 수식을 이끌어 낼 수 있다. 이를 통해, Spoke type PMSM은 마그네틱 토크가 주 토크이기 때문에, 공극 자속밀도 및 형상치수비를 이용하여 전동기의 크기를 계산하였다.

• The korean journal of orthodontics
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• v.1 no.1
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• pp.15-20
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• 1970

The author investigated on the responses of pulp and dentine following tooth movements. The material consisted of fifty-four intact teeth from twenty-seven adult white rats. The half of the teeth were employed as controls and the other half served as experimental group. These teeth were moved with forces ranging from 30 grams to 120 grams for from 3 to 7 days. All these were extracted immediately after the force was relieved. The main pulp changes in the experiment were vacuolization of the pulp tissue and circulatory disturbances. The magnitude of the force had an important role. In addition to these changes, the resorption in dentine and cementum was observed, which was related to the magnitude of the force and the duration of experiment.

• Journal of Navigation and Port Research
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• v.26 no.1
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• pp.101-105
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• 2002

Many malfunction take place in container crane spreader due to impact. So we designed a 2 DOF hydraulic impact absorbing equipment to absorb the impact and we studied the change of damping coefficient with respect to the variation of dimensions of oil-Cylinder wail. When we design the dimension of hydraulic cylinder wall considering the displacement on the wall, the value of it over 20m didn't affect the damping coefficient.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.792-797
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• 1996

형상모델링(Geometric Modeling)은 컴퓨터 기술의 발전과 더불어 실제 3차원 물체를 정확하게 표현하려는 형태로발전하였다. 와이어프레임 모델링(Wireframe Modeling) 기술은 3차원 형상을 빠르게 모델링하고 이로 부터 치수 기입이 된 정확한 2차원 도면의 생성을 가능하게 하였다. 그러나, 면을 표현할 수 없기 때문에 모델의 표현이 모호해질 수 있다. 1960년대에 자유곡면의 가공을 위해 개발된 곡면 모델링(Surface Modeling) 기법은 NC 가공과 컴퓨터를 이용한 금형의 제작을 가능하게 했고 와이어프레임 모델링보다는 더 상세하게 모델 을 표현할 수 있게 되었다. 본 연구의 목적은 개방형 구조를 갖는 복합다양체 모델러에서의 불리안 작업을 구현하고 이의 결과를 가시화 하는데 있으며 개략적인 개방형 형상 모델링 시스템 Fig.1과 같다

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.3
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• pp.337-344
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• 2014

An optimal shape design algorithm is suggested to systematically design a traditional Korean musical instrument, the Pyeongyeong. The Pyeongyeong consists of 16 different chime stones called Gyeongpyeons. The first natural vibration frequency of each Gyeongpyeon must be adjusted to its target frequency, which is determined by the traditional sound tuning method. The second and third natural frequencies must be proportional to the first natural frequency with a specific ratio (1:1.498:2.378). The key idea in our suggested design algorithm is to use the sensitivity of natural frequencies to the variation in the length of each side of a Gyeongpyeon. The dimensions of five different Gyeongpyeons are determined by following the suggested algorithm. Changes in natural frequencies with respect to local thickness variation are closely investigated to compensate for errors that may occur during manufacturing.

• Elastomers and Composites
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• v.48 no.4
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• pp.300-305
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• 2013

Part shrinkage in injection molding is inevitable phenomenon. Thus, it is necessary not only study on the reducing part shrinkage but characterization of part shrinkage. In this study, part shrinkage in injection molded 2.5 dimensional annular shaped specimens has been studied using glass fiber reinforced PC. Annular shaped specimens were designed with various sizes of outer diameter and thickness. Injection temperature, packing time and packing pressure were selected for operational conditions. Profile variations of outer and inner diameters of molded specimens for various operational conditions were investigated. Sizes of outer and inner diameters of injection molded specimens were smaller than the sizes of mold. Part shrinkage decreased as outer diameter and thickness increased. Part shrinkage showed anisotropic behavior and it depended upon gate location. Subsequently, molded specimens were not circular but oval in shape, and showed the largest shrinkage in the direction of gate. It was realized that the mold design such as gate design is important to control the shape of molded products.

• Tribology and Lubricants
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• v.32 no.4
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• pp.119-124
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• 2016

In the sapphire wafering process, lapping is a crucial operation in order to reduce the damaged layer and achieve the target thickness. Many parameters, such as pressure, velocity, abrasive, slurry and plate, affect lapping characteristics. This paper presents an experimental investigation on the effect of the plate groove on the material removal rate and roughness of the wafer. We select the spiral pattern and rectangular type as the groove shapes. We vary the groove density by controlling the groove shape dimension, i.e., the groove width and pitch. As the groove density increases to 0.4, the material removal rate increases and gradually reaches a saturation point. When the groove density is low, the pressing load is mostly supported by the thick film, and only a small amount acts on the abrasives resulting to a low material removal rate. The roughness decreases on increasing the groove density up to 0.3 because thick film makes partial participations of large abrasives which make deep scratches. From these results, we could conclude that the groove affects the contact condition between the wafer and plate. At the same groove density, the pitch has more influence on reducing the film thickness than the groove width. By decreasing the groove density with a smaller pitch and larger groove width, we could achieve a high material removal rate and low roughness. These results would be helpful in understanding the groove effects and determining the appropriate groove design.

• Fashion Information and Technology
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• v.1
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• pp.45-54
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• 2004

• Proceedings of the KWS Conference
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• 2008.05a
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• pp.18-18
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• 2008

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1991.04a
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• pp.96-102
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• 1991

절삭가공의 목적은 소재의 불필요한 부분을 chip으로 제거하여 소요의 형상 치수인 새로운 표면을 만들어 내는 것이다. 실제 가공에서 소요되는 동력을 보면 대부분은 chip을 만들어 내는데 소비되기 때문에 chip의 특성은 절삭가공에 있어서 극히 중요한 인자가 되는 것이다. 본 연구에서는 많이 사용되고 있는 throw away 공구에서의 칩 브레이커의 성능을 향상시키기 위하여 실험을 통하여 기존에 사용되고 있는 공구들의 성능을 평가하고 문제점을 제시한다.