• 드라이브 ㆍ 컨트롤
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• 제12권1호
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• pp.9-14
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• 2015

In the early of 1950, the high response magnetic torque motor was developed for driving electro-hydraulic servo valves. Since then it has been broadly used for industrial application and the research of development or improvement of the torque motor is still being conducted. The purpose of this study is to present useful design criteria for the torque motor design. For this, torque motor is modelled and linearized. The static characteristics of the torque motor are investigated by direct computation of the derived linearlized equations. The dynamic characteristics of the torque motor are investigated with the derived transfer function by using Matlab and compared with the results of the linearlized analysis by using AMESim simulation with actual values of the physical parameters. Finally, the design criteria obtained from the analysis are reviewed.

• 한국가스학회지
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• 제11권4호
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• pp.59-63
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• 2007

The purpose of this paper is to find optimum vent port of the booth for gas explosion experiment. Also, it is to understand the safety of the booth for explosion experiment which is installed to let the trainees for legal education which is managed by IGTT(Institute of gas technology training) blow the riskiness of explosion. Since the booth for gas explosion experiment is a confined space, we used the exhaust model for indoor explosion. As the result, it was safety calculated when the amount of leaking gas was close to the maximum of explosion limit on the explosion experiment.

• 한국정밀공학회지
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• 제17권11호
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• pp.55-62
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• 2000

The poor machinability material such as austenite stainless steel(STS304) is emphasized on the wide use of HSSE for the tapping operation. The difficulty can be entirely to tapping torque due to chip formation through the hole of tap. The object of this study is to investigate tap geometry affecting the tapping torque from a practical point of view. The study shows that the optima tapping torque is affected by the tap geometry and cutting condition for STS304.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2007년도 추계학술발표논문집
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• pp.140-143
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• 2007

본 연구의 목적은 반도체 후공정 제조 시스템인 Screen Printer시스템에서의 프린팅 공정시 프린팅에 사용되는 Mesh Mask, Urethane Blade의 재질이 사용되는 반복횟수의 증가에 따라 재질의 변화에 의한 문제점과 프린팅 공정 파라미터인 Table 접촉거리, Squeegee 하강위치의 주변환경에 의한 변화를 보상하여 일정하게 프린팅이 될 수 있는 시스템을 구현 하는데 목적이 있으며, 이 논문은 서보모터를 구동하는 위치제어 시스템에 로드셀（Loadcell）을 이용하는 압력제어시스템을 연구하고 구현하고자 하였다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2009년도 추계학술대회
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• pp.422-424
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• 2009

본 논문은 반도체 제조 장비 중 몰드 장비에서 슬릿빔을 이용하여 칩 적층 높이를 측정하는 방법을 연구하였다. 본 논문에서는 슬릿빔을 이용한 높이 측정 방법의 기본 원리를 응용하여 반도체 제조 장비 안에 적용하면서 칩의 적층높이 측정 성능을 높이기 위하여 두 가지 방법을 연구하였다. 첫째로, 카메라 노출 시간과 높이 측정 반복성의 관계이며, 둘째는 PCB(Printed Circuit Board)휨 현상에 대한 측정 오류 최소화를 위하여 최소자승법을 응용하여 측정 성능을 향상 시킬 수 있었다.

• 반도체디스플레이기술학회지
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• 제22권2호
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• pp.40-44
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• 2023

The defect detection based on deep learning requires minimal loss and high accuracy to pinpoint product defects. In this paper, we confirm the loss rate of deep learning training based on disc-shaped artificial scaffold images. It is intended to compare the performance of Cross-Entropy functions used in object detection algorithms. The model was constructed using normal, defective artificial scaffold images and category cross entropy and sparse category cross entropy. The data was repeatedly learned five times using each loss function. The average loss rate, average accuracy, final loss rate, and final accuracy according to the loss function were confirmed.

• 반도체디스플레이기술학회지
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• 제8권4호
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• pp.53-58
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• 2009

A SMT mounter is a kind of equipment that mounts SMD parts quickly on the printed circuit board. By using linear motors, it is controlled with high speed and precision, which is similar to semi-conductor and display process equipment. It is necessarily used in an assembly process of an electronic device. Mobile devices such as a mobile phone and PDA are required to reduce mount areas due to the demands for high performance and small size. Hence, super small sized and complex mobile devices have been developed. To improve the productivity of the corresponding equipment, designs with large sized, high speed, and multidisciplinary functions have been consistently performed. Meanwhile, a design trend of large size and light-weight on SMT mounter causes a low natural frequency of systems and vibration problems at the high speed operation. In this paper, the dynamic characteristics of the SMD mounter system were investigated through a modal test and transmissibility test, and verified by finite element method. Also, various design improvement was performed to avoid the resonance phenomena.

• 반도체디스플레이기술학회지
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• 제4권4호
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• pp.1-4
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• 2005

The chemical composition and uniaxial compressive stress are varied to observe their effect on the current-voltage characteristics of ZnO based ceramics. The variation of chemical composition produces two kinds of ceramics showing ohmic and nonohmic current-voltage characteristics. The current at a fixed voltage increased with the increase of the compressive stress for both ohmic and nonohmic ceramics. Ceramics showing nonohmic behavior exhibit better reversible return of current-voltage curve when the applied compressive stress is removed from the ceramics than those showing ohmic behavior do. We found an appropriate chemical composition showing linear relation between current and stress at a fixed voltage. The ceramic materials with an appropriate chemical composition can be used as a potential sensing material in pressure sensors.

• 반도체디스플레이기술학회지
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• 제4권3호
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• pp.29-33
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• 2005

As the integrated devices become more and more sophistcated, the diameter of wafers increased up to 300 mm and strict level of cleaning is necessary to remove the particulates on the surface of wafer. Therefore we need a new type of wet-station which can reduce DI water and chemical in the cleaning process. Moreover, it is important to control the temperature and the concentration of chemical in the wet-station. In the conventional chemical supply system, it is difficult not only to fit the mixing rate of chemicals in cleaning process, but also to fit the quantity and temperature. Thus, we propose a new chemicals supply system, which overcomes above problems by the analysis of fluid and thermal transfer on chemical supply system.

• 실천공학교육논문지
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• 제11권2호
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• pp.159-165
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• 2019

공학교육인증제도 아래 기초설계-요소설계-종합설계의 3단계의 교육체계로 시행되고 있는 공학설계교육 중, 기초설계에 서는 설계 개념, 절차의 공학 입문자에의 소개와 동시에 종합설계에 연결하여 효과적으로 사용되도록 수학적인 상세 설계보다는 창의성이 발휘된 설계안을 창안, 평가하는데 중점을 두고 이를 팀 활동을 통해 연습시킨다. 본 연구에서는 기초설계를 수강하고 종합설계를 수행하고 있는 기계 분야 학생들의 의견을 설문을 통해 수집하여 효과적인 기초설계 교육이 이루어지고 있는지 알아보았다. 전반적으로 학생들이 기초설계 교육의 중요성을 높게 인식하며 유용도도 높다고 인식하고 있으며, 교과 내용별 중요도 및 유용도, 교육기반 및 환경, 종합설계와의 연계 필요성 등 기타 평가사항들이 앞서 있었던 기계 분야 교수들에 대한 설문 결과와도 상당히 일치하고 있다. 학생들과 교수들의 인식이 잘 공감되고 있으며 실제 종합설계시 팀 활동과 아이디어 창안 등이 잘 활용되고 있는 것으로 미루어 기초설계 교육이 효과적으로 이루어지고 있음을 확인할 수 있었다. 다만, 유용도가 중요도에 비해 약간 낮게 인식되는 점은 실습 과제를 흥미롭고 현실적인 것으로의 지속적 향상, 종합설계 초기에 기초설계 습득 내용이 응용되도록 유도하는 등의 유용도를 더 높이기 위한 방안과 노력이 필요하다는 것을 보여준다.