• 제어로봇시스템학회논문지
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• 제16권11호
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• pp.1089-1095
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• 2010

We propose an image segmentation method for auto-teaching system of PCB (Printed Circuit Board) assembly inspection machines. The inspection machine acquires images of all components in PCB, and then compares each image with its standard image to find the assembly errors such as misalignment, inverse polarity, and tombstone. The component window that is the area of component to be acquired by camera, is one of the teaching data for operating the inspection machines. To reduce the teaching time of the machine, we newly develop the image processing method to extract the component window automatically from the image of PCB. The proposed method segments the component window by excluding the soldering parts as well as board background. We binarize the input image by use of HSI color model because it is difficult to discriminate the RGB colors between components and backgrounds. The linear combination of the binarized images then enhances the component window from the background. By use of the horizontal and vertical projection of histogram, we finally obtain the component widow. The experimental results are presented to verify the usefulness of the proposed method.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제10권1호
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• pp.31-45
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• 2006

최근 고집적화, 고밀도화 되어가는 첨단 디바이스와 섬세한 공정들은 SMT(surface mounting technology)에서의 더욱 까다로운 검사 항목들을 요구하고 있다. 특히, 어셈블리 생산품의 불량의 60% 이상을 차지하는 솔더 프린팅의 검사는 이러한 추세에 대응책으로 3차원적인 검사방식이 기존의 2차원적인 검사방식을 빠르게 대치해나가고 있다. 따라서 본 논문에서는 SMT 어셈블리 라인에서 PCB(Printed circuit board)에 프린팅된 솔더 페이스트에 대한 3차원적인 검사를 자동으로 수행하는 인라인형의 고속 3차원 검사 장비 및 측정 알고리즘을 제안한다. 제안한 방법은 3차원 데이터를 B-스플라인으로 표면을 구성한 다음 이를 기반으로 패드를 추출하고, 검사하는 알고리즘이다.

• 한국압력기기공학회 논문집
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• 제7권4호
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• pp.19-25
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• 2011

Steam Generator(SG) tube is an important component of Nuclear Power Plant(NPP), which is the pressure boundary between the primary and secondary systems. The integrity of SG tube has been confirmed by the eddy current test every outage. The eddy current technique adopting bobbin probe is currently the primary technique for the steam generator tubing integrity assesment. The bobbin probe is one of the essential components which consist of the whole ECT examination system and provides us a decisive data for the evaluation of tube integrity. Until now, all of the ECT bobbin probes in Korea which is necessary to carry out inspection are imported from overseas. However, KHNP has recently developed the bobbin probe design technology and transferred it to domestic manufacturers to fabricate the probes. This study has been conducted to establish technical requirements applicable to the steam generator tube inspection using the bobbin probes fabricated by the domestic manufactures. The results have been compared with the results obtained by using foreign probe to identify the availability to the steam generator tube inspection. As a result, it is confirmed that the domestic bobbin probe is generally applicable to SG tube inspection in the NPPs.

• 한국식품영양학회지
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• 제27권3호
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• pp.447-457
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• 2014

A research was conducted on Seoul regional elementary, middle, and high school nutritionists to study about their perception of HACCP control standards & performance conditions and sanitation & safety inspection, to seek for more efficient methods of school meals' sanitation system settlement. All surveys were distributed and collected via email. A total of 305 survey papers were collected, and out of these, 300 school results were analyzed. As for CCP 1 performance conditions, 43.3% of the nutritionist put emphasis on temperature control for cooking duration and 71.0% said that they manage both temperature and PHF food control. In CCP 2 stage, 65.8% of the nutritionists maintained the food's temperature, and 56.7% documented the recordings after cooking. A total of 79.3% of the schools scored above 90 points on school meal sanitation & safety inspection, 3.72 points on necessity for revisions, 3.38 points on objectivity, and 3.34 points on reliability. As for these results, a clear CCP control criteria as well as training must be set. Also, because the necessity of revision for sanitation & safety inspection is higher than reliability and objectivity, appropriate complementary measures must be taken.

• 산업경영시스템학회지
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• 제18권34호
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• pp.155-159
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• 1995

For the relationship between conformance cost and the individual elements of non-conformance, an analysis was made of the relationship between inspection cost and training cost and scrap cost. As a result it was explained that there was all a positive correlation between training cost and scrap cost, and between inspection cost and scrap cost. Like this, training and inspection cost and scrap cost have a positive correlation. Judging from the fact that the coefficient of inspection cost is lower than that of training cost in the comparison of the coefficient of each cost, it can be analyzed that the change in scrap cost is influenced by the change in training cost more greatly than the change in inspection cost. If doing so, it can be interpreted that scrap cost and rework cost do not still decrease in spite of increasing in education and training cost and prevention cost. This result may represent the problem as to whether education and training cost is effectively expended for prevention activity. Accordingly, to cope with this situation, it is thought that scrap cost should be cut by establishing the effective prevention measure for causing the increase of scrap cost.

• 한국동물위생학회지
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• 제35권2호
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• pp.129-131
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• 2012

Blood samples were collected from 672 goats in 60 farms from five provinces of Korea between November 2009 and August 2011. The prevalence of antibodies to pestiviruses was investigated. The examination for antibodies was performed using an enzyme-linked immunosorbent assay (ELISA) detecting antibodies to the bovine viral diarrhea virus (BVDV) and border disease virus (BDV). All blood samples were screened using reverse transcription-polymerase chain reaction (RT-PCR) with primer pairs specific to common pestivirus genome regions. The observed individual seroprevalence was 1.49% and herd seroprevalence was 11.67%. Also, the specific genomes to pestiviruses were detected in 3 out of the 915 clinical samples (0.45%). Based on the nucleotide sequence data, detected pestiviruses were belonged to two BVDV type-1 and one BVDV type-2. The pestivirus infection has been occurred among Korean black goats. However, our results indicate that the prevalence of pestiviruses in black goats was not significantly higher on farms with cattle.

• 한국항공운항학회지
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• 제26권4호
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• pp.116-121
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• 2018

According to the incresement of aging aircraft, Republic of Korea Air Force (RoKAF) conducted a teardown inspection of aircraft's EWIS (electrical wiring interconnection system) to determine the status of deterioration and the influence of failure occurrences due to it. The inspected aircraft were the retired fighter jets that had been used for more than 40 years. By analyzing defect type and the defect tendency, RoKAF can establish the necessary measures for the usage extension of their fleet and furthermore, the analysis results can be used as a basic data for the preparation of it's aircraft aging. EWIS inspection was done throughout careful visual inspection technique by removing all the ducts and pipes located in the fuselage and wings. For the aircraft wiring where no damage was found, the elongation tests were performed to determine the deterioration of wiring according to the location of the aircraft. The connectors, which is the main cause of intermittent failure, were completely disassembled and inspected for internal damage such as corrosion, abrasion, and traces of foreign objects. The detected defects were classified into 4 severity levels based on the type of damage, and the classified defects were weighted according to the criticality which may affects to it's system to establish the action plan.

• 한국식품위생안전성학회지
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• 제36권3호
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• pp.239-247
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• 2021

본 연구는 2019년 1월 1일부터 전체 농산물에 확대 적용된 농약 허용물질목록관리제도(PLS)가 미치는 영향을 확인하기 위해 2018년부터 2020년까지 경기도 유통 농산물 검사 자료 28,693건을 대상으로 잔류농약 실태를 조사하였다. 전체 검사 실적 대비 기준 초과 비율은 2018년 1.0%, 2019년 1.2%, 2020년 1.2%로 나타났고, 잔류농약 검출 비율은 2018년 12.9%, 2019년 25.1%, 2020년 37.3%로 증가하였다. 2019년 기준초과 114건 중 55건이 일률기준(0.01 mg/kg) 적용이었고, 2020년 기준초과 115건 중 66건이 일률기준 적용이었다. 이를 개선하기 위해서는 비의도적 오염, 미등록 작물에 관행적 사용, 부정 농약에 대한 관리가 필요해 보인다. Fluquinconazole은 비의도적 오염이 원인이었고, diazinon, chlorothalonil, methabenzthiazuron은 미등록 작물에 관행적 사용이 원인이었다. Chinomethionat은 과거에 폐기된 농약 성분으로 밀수 농약 사용이 원인이었다. 본 연구 결과와 이후 모니터링 자료는 앞으로 제도 보완 및 현장 관리 강화를 위한 기초자료로 활용될 수 있을 것이다.

• 한국구조물진단유지관리공학회 논문집
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• 제4권3호
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• pp.161-168
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• 2000

A series of in-situ inspection and measurements have been conducted to estimate rebar corrosion incidence of concrete bridges in Seoul metropolitan area. The objectives of this study were to obtain the fundamental data to analysis the causes of rebar corrosion and to establish the repair strategies of deteriorated concrete bridges due to corrosion. The results of this study had been analysed to identify the extent of chloride content and incidence of rebar corrosion by construction ages and by members. After measuring chloride content in concrete, it was concluded that about 76% of all tests on samples from concrete exceed the maximum acceptable limit to risk of chloride-induced corrosion. On the whole, slabs had the most highly chloride content. About 16% of the concrete bridges had a value lower than -350mV (vs. CSE), so it could concluded that the excessive chloride content and carbonation were a major causes of rebar corrosion. Concrete member which carbonation depth penetrates toward rebar was 39% among all tests on samples. The major causes of rebar corrosion were highly chloride content 50%, concrete carbonation 38%, poorly visual condition 6% and etc, 6%.

• 품질경영학회지
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• 제32권1호
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• pp.63-74
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• 2004

Recently, enterprises have focused on quality improvement for delighting their customers. Especially, all business sector have checked, analyzed their consumer complaints in detail on their products and made a plan to reduce them. But there is a limitation not to solve them. This paper presents one of tools to reduce non qualified product on their operation line directly by modernized IT technology after analyzing and making the plan.