• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.579-582
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• 2002

In acquiring the surface information of a part, two types of measuring machines have been used: contact type and non-contact type. Since each measuring device has the pres and cons, an integrated measuring system is proposed to acquire the optimal point data. In order to implement the integrated measuring system, the relationship of coordinate systems between each measuring device should be established. In this paper, a new datum fixture and a calibration method for the multiple-sensor measuring system are proposed. The datum fixture is designed to interface two machines, a CMM and a laser scanner. The position of the datum fixture is calibrated by the axis information off motorized rotation stage which is used for a part setup.

• 한국경영과학회지
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• 제21권3호
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• pp.143-157
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• 1996

This paper addresses the effects of an imperfect production process on the optimal production quantity and quality inspection policies. The system is assumed to deteriorate during the production process. The result are either the production of a number of defective items or the breakdown of the production meachine. A simple rule has been suggested to determine whether multiple quality in spection is workth or not. Furthermore, when multiple inspection policy is adopted, the optimal in spection schedule is shown to be equally spaced throughout the production cycle. Exact solution and approximation of the optimal production quantity and approximation of the optimal number of inspection are provided. Finally , to better understand the model of this paper, comparisons between this model and classical EMQ model are provided.

• 한국산학기술학회논문지
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• 제8권4호
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• pp.930-937
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• 2007

본 논문에서는 단계별로 검사공정과 재가공공정으로 구성된 K단계 검사시스템의 설계문제를 다루며 사례연구를 제시한다. 검사원의 Type I과 II의 오차를 가정하고, 양품으로 분류된 제품도 재검사를 한다는 정책 하에 목표 불량률을 달성할 수 있는 가장 작은 정수인 K값을 결정한다. 만약 K값이 존재하지 않을 경우 Type I과 II의 오차는 변하지 않는다고 가정하여 목표 불량률을 달성할 수 있는 (조립생산라인의 불량률, 재가공불량률)을 역으로 탐색한다. 본고에서 제시된 K단계 검사시스템에 대한 공식과 방법론은 약간의 수정을 가한다면 유사한 검사환경에 적용할 수 있다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 추계학술대회 논문집
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• pp.158-163
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• 2002

This paper presents a multiple sensor system for rapid and high-precision coordinate data acquisition in the OMM (On-machine measurement) process. In this research, three sensors (touch probe, laser, and vision sensor) are integrated to obtain more accurate measuring results. The touch-type probe has high accuracy, but is time-consuming. Vision sensor can acquire many point data rapidly over a spatial range but its accuracy is less than other sensors. Also, it is not possible to acquire data for invisible areas. Laser sensor has medium accuracy and measuring speed among the sensors, and can acquire data for sharp or rounded edge and the features with very small holes and/or grooves. However, it has range- constraints to use because of its system structure. In this research, a new optimum sensor integration method for OMM is proposed by integrating the multiple-sensor to accomplish mote effective inspection planning. To verify the effectiveness of the proposed method, simulation and experimental works are performed, and the results are analyzed.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2006년도 하계학술대회
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• pp.91-94
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• 2006

In this paper, we deployed the tunnel inspection and monitoring system by wireless sensor network. It is shown that the wireless sensor network which is composed of sensor, wireless communication module, and gateway system can be applied to tunnel monitoring system. Sensors included herein are acceleration transducers, fire-alarm sensors, water-level sensors, and magnetic contact sensors. It is also found that the wireless sensor network can deliver sensing data reliably by ad-hoc networking technology. The gateway system that can send the sensing data to server by CDMA (code division multiple access) is developed. Finally, monitoring system is constructed by web service technology, and it is observed that this system can monitor the present state of tunnel without difficulties. Furthermore, the above system provides an alternative to inspect and monitor the tunnel efficiently where the conventional wired system cannot be applied.

• 한국항공운항학회지
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• 제24권2호
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• pp.59-67
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• 2016

The checklist currently used for Aviation safety inspection performed by ASIs consists of inspection groups and multiple items, it does not have structured hierarchy system which required to efficiently process aviation safety analysis. On this study, through mapping taxonomy of HFACS onto current checklist to secure structured hierarchy system and present a specification on systematic frequency and severity to perform safety risk assessment of detected hazard.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 추계학술대회 논문집
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• pp.309-310
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• 2006

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1780-1781
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• 2011

There have been numerous studies on application of robots to in-pipe inspection system. In this thesis, a mobile robot that can move through elbows and vertical pipes having diameter 100mm is developed. Defect detection technology for locating wall-thinnings, corrosions and foreign materials is developed for high temperature and pressure pipings in thermal power plants, utilizing laser sensors installed on the robot. Actual defect detection performance is evaluated with application of the developed robot system to a mock-up pipings.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.105-109
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• 2001

The micro optical parts such as ferrules are required to be manufactured within very small tolerances, as the slight deviation of the tolerance would give very large amount of loss in communication efficiency. For efficient optical communication, outer diameter, fiber diameter, fiber separation and eccentricity are significant parameters to be inspected., Thus we developed an automatic inspection system to evaluate shape parameters of the optical fiber connectors(ferrule) upto submicron accuracy using machine vision. new optical probe of multi fields of views has been developed and the image processing and data analysis algorithms have been complemented in real time basis. The developed system is successfully used in the practical ferrule manufacturing industry, and about 0.1$\mu\textrm{m}$ accuracy can be obtained with very fast inspection time.

• 마이크로전자및패키징학회지
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• 제19권1호
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• pp.81-87
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• 2012

본 논문에서는 마이크로 BGA 패키지 내외부의 마이크로 볼의 3차원 형상을 측정하는 광학 측정 시스템을 제안하고 이를 구현한다. 대부분의 시각 검사 시스템은 마이크로 볼의 복잡한 반사 특성 때문에 검사에 어려움을 겪고 있다. 정확한 형상의 측정을 위해서, 특별히 설계된 시각 센서 시스템을 제안하고, 위상이송 모아레 간섭계의 측정원리에 기반한 형상측정 알고리즘을 제안한다. 센서 시스템은 4개의 서브시스템을 보유한 패턴 투사 시스템과 영상획득 시스템으로 구성된다. 패턴 투사용 서브시스템은 공간상으로 서로 상이한 투사 방향을 가지며, 이는 측정 물체에 각기 다른 입사 방향을 가지는 패턴 조명이 투사될 수 있도록 하는 것을 목적으로 한다. 위상이송 모아레 간섭계의 구현을 위한 정밀 위상이송을 위해서, 각 서브시스템의 패턴 격자는 PZT 구동기를 이용하여 일정 간격으로 이송한다. 최종적으로 측정되는 마이크로 볼의 경면반사와 그림자 영역을 효과적으로 제거하기 위해서, 다중 패턴 투사 시스템과 영상획득 시스템을 구현하고, 이를 테스트한다. 특히, 다중 프로젝션을 이용하여 획득되는 다중 높이 정보를 효과적으로 융합하기 위하여, 베이지안 센서 융합 이론을 기반으로한 센서 융합 알고리즘이 제안된다. 제안되는 시스템의 원리검증과 성능확인을 위해, 마이크로 BGA볼과 기판 범프의 측정대상물에 대해서, 측정 반복성을 중심으로 실험이 수행되었으며, 획득된 실험 결과를 분석하고 논의한다.