• 대한안전경영과학회지
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• 제10권3호
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• pp.253-265
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• 2008

In this paper, we developed a heuristic algorithm to assign job to workers in parallel line inspection process without sequence. Objective of assigning job in inspection process is only to assign job to workers evenly. But this objective needs much time and effort since there are many cases in assigning job and cases increase geometrically if the number of job and worker increases. In order to solve this problem, we proposed heuristic algorithm to assign job to workers evenly. Experiments of assigning job are performed to evaluate performance of this heuristic algorithm. The result shows that heuristic algorithm can find the optimal solution to assign job to workers evenly in many type of cases. Especially, in case there are more than two optimal solutions, this heuristic algorithm can find the optimal solution with 98% accuracy.

• International Journal of Precision Engineering and Manufacturing
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• 제7권3호
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• pp.18-23
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• 2006

The formation degree of sustain (ITO pattern) determines the quality of a PDP (Plasma Display Panel). Thus, in the present study, we attempt to detect 100% of the defects that are larger than $30{\mu}m$. Currently, the inspection method in the PDP manufacturing process is dependent upon the naked eye or a microscope in off-line mode. In this study, a prototype inspection system for PDP ITO patterned glass is developed. The developed system, which is based on a line-scan mechanism, obtains information on the defects and sorts the defects by type automatically. The developed inspection system adopts a multi-vision method using slit-beam formation for minimum inspection time and the detection algorithm is embodied in the detection ability. Characteristic defects such as pin holes, substances, and protrusions are extracted using the blob analysis method. Defects such as open, short, spots and others are distinguished by the line type inspection algorithm. It was experimentally verified that the developed inspection system can detect defects with reliability of up to 95% in about 60 seconds for the 42-inch PDP panel.

• 품질경영학회지
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• 제23권4호
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• pp.74-89
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• 1995

In recent years, the safety of customers and the demand for rights to be protected from the risk have become stronger than ever day by day, and the function concerning product liability(PL) and quality assurance(QA) has been emphasized. Basically these functions can be obtained by inspection and there is the single rectifying sampling inspection for attribute (KSA-3105) as an existing method. But we can not say this method is good enough because of limitations in the range of applications and the approximate design of inspection methods which can not meet the rapidity and accuracy of quality information transfer according to the maturity of information period. Therefore, in this paper, a new algorithm is developed which can design the accurate inspection method by using the linear cost function that has not been considered in the existing inspection methods. Also in addition to this, a optimal rectifying sampling inspection plan, contributing to minimize the total costs, can be developed by programming the algorithm developed in this study and it can be applied to any field having many processes almost limitlessly.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 A
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• pp.291-294
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• 2003

In this paper, 2D and 3D inspection algorithm for printed solder on PCB is introduced. The aim of inspection is the detection of error such as rich solder poor solder and missing solder. For Inspection, laser distance sensor is used. For 2D inspection, laser image that is created by normalizing laser data between 0 and 255 are used. Reference Image is made using gerber file. Image processing algorithm is used for 2D inspection. By adding thickness of metal stencil to laser image, volume for solder can be calculated and 3D inspection is carried out.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2010년도 춘계학술대회
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• pp.574-576
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• 2010

본 논문에서는 CCD 카메라를 이용해 리드프레임의 내부 리드부의 넓이와 선명도 및 결함 등을 고속으로 검사하는 시스템을 개발한다. 본 시스템은 조명부, 검사부, 조명 제어부, GUI 등으로 구성된다. 개발 기술로는 조명 제어, 고속 검사 알고리즘, 검사 분해능을 올리기 위한 계측기술 등이다. 현장 실험을 통해 개발된 시스템의 유효성을 검증한다.

• 한국압력기기공학회 논문집
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• 제7권3호
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• pp.8-14
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• 2011

The clogging of the flow area at the tube support plates(TSPs), especially at the upper TSPs results in the water level oscillation of a steam generator during normal operation. A reduction of the TSP flow area causes to increase in pressure drop within the two-phase flow zone, which destabilizes the boiling flow through the tube bundle. This phenomenon was occasionally observed at a few domestic and foreign nuclear power plants. One of the methods for defining the flow area clogging is visual inspection, which is the most effective inspection method. The results of the visual inspection for TSPs' flow area are clogging images on TSPs' quartrefoil lobes. These images are complexly distorted due to lens aberration and external factors like the distance to a subject and angle etc. In this work, we developed the analysis algorithm for clogging image of the TSP flow area of steam generators. For this purpose, we designed an image verification device applicable to the camera employed in the field for visual inspection and then, we demonstrated the validity of image analysis algorithm by using this device and commercial autoCAD program.

• 품질경영학회지
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• 제27권3호
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• pp.113-124
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• 1999

Inspection policies deal with stochastically failing systems in which failures cannot be detected without inspection. In this paper, we considered an effective inspection policy to detect system failure under imperfect inspection. Approximate total expected cost is derived and a simple algorithm to determine inspection schedule is Presented. Numerical examples showed that the inspection policy is easily applicable and cost effective.

• 한국정보통신학회논문지
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• 제23권2호
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• pp.127-132
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• 2019

본 논문에서는 사출성형 자동차부품의 외관 품질과 생산성을 높이기 위하여 사출성형 자동차부품의 외관 비전검사 방법을 제안한다. 일반적으로 기존 사출성형 자동차부품의 외관검사는 사람에 의한 매뉴얼 샘플링 검사로 진행된다. 먼저 전자부품(TFT-LCD 및 PCB 등) 비전검사에 활용되는 Edge-Tolerance 비전검사 알고리즘([1]-[4])을 사출성형 부품 외관검사에 적용하고, 그 문제점을 파악하였다. 그리고 그 문제점을 극복하는 새로운 외관 비전검사 방법을 제안한다. 제안된 외관비전검사는 양품 기준영상을 기준으로 검사하고자 하는 부품의 검사영상을 정렬한 후, 부분적인 적응적 이진화 후, 이진블록매칭 알고리즘을 이용하여 양품 이진영상과 검사이진영상을 블록단위로 비교함으로써 불량부분을 검출한다. Edge-Tolerance 비전검사 알고리즘과 제안된 외관비전검사 방법을 실제 개발된 장비를 이용하여 다양한 비교 실험을 통하여 그 효용성을 검증하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.173-176
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• 2002

In this paper, we present the combined 2-D and 3-D algorithms for automatic solder paste inspection. For automatic inspection, optical system for the combined inspection and driving unit is made. One-pass run length algorithm that has fast and efficient memory space is applied to the input image fur extracting solder paste patterns. The path of probe movement is then calculated for an automatic inspection. For a fast 3-D inspection, the phase shift algorithm based on Moire interferometry is also used. In addition, algorithms used in this paper are coded by $MMX^{TM}$. A probe system is manufactured to simultaneously inspect 2-D and 3-D for 10mm$\times$10mm field of view, with resolutions of 10 $\mu\textrm{m}$for both x, y axis and 17 $\mu\textrm{m}$for z axis, and then, experiments on several PCBs are conducted. The processing times of 2-D and 3-D, excluding an image capturing, is 0.039 sec and 0.047 sec, respectively. The credible result with $\pm$ 1$\mu\textrm{m}$uncertainty can be also achieved.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2011년도 춘계학술대회
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• pp.813-815
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• 2011

본 연구에서는 자동차 성형 조립품의 불량 및 부품의 조립상태를 고속, 고정밀도로 검사하고 여러제품에 적용 가능한 범용 검사 시스템을 제안한다. 검사 프로그램은 검사 대상의 표면 검사 및 조립상태 검사를 위한 결함 검사 알고리즘, 실시간 검사를 위한 고속처리 알고리즘으로 구성된다. 결함검사 알고리즘은 크게 ROI 영역내의 픽셀 평균을 이용하는 방법과 영역분할 및 객체 유무 판단을 통해서 이루어진다. 본 검사 시스템의 정확도, 처리 시간 등의 평가를 통해서 시스템의 효율성을 확인하였다.