• 한국멀티미디어학회논문지
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• 제24권8호
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• pp.988-999
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• 2021

AOI (Automatic Optical Inspection) of PCB (Printed Circuit Board) is a very important step to guarantee the product performance. The process of registering components called teaching mode is first perform, and AOI is then carried out in a testing mode that checks defects, such as recognizing and comparing the component mounted on the PCB to the stored components. Since most of registration of the components on the PCB is done manually, it takes a lot of time and there are many problems caused by mistakes or misjudgement. In this paper, A components classifier is proposed using YOLO (You Only Look Once) v2's object detection model that can automatically register components in teaching modes to reduce dramatically time and mistakes. The network of YOLO is modified to classify small objects, and the number of anchor boxes was increased from 9 to 15 to classify various types and sizes. Experimental results show that the proposed method has a good performance with 99.86% accuracy.

• 과학교육연구지
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• 제36권1호
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• pp.153-165
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• 2012

이 연구에서는 중학생(N=300)을 대상으로 질문지와 면담을 통해 주요 동물의 분류에 관한 오류와 그 이유가 되는 사고 내용을 조사하였다. 연구결과, 척추동물과 무척추동물로 분류하는데 있어서 뱀(31.7%), 새우(28.3%), 거북이(25.6%), 개구리(24.7%), 불가사리(10.7%) 등의 순서로 오류의 빈도가 높았다. 이러한 오류의 이유는 각 동물의 운동 특성과 외형적 특성에 따른 직관적 사고, 다른 동물의 특성에 비유하여 잘못된 유추를 하는 것, 각 동물의 척추 관찰 부족 때문인 것으로 나타났다. 또한 척추동물의 하위분류군을 구분함에 있어서 '도롱뇽은 파충류(45.3%), 거북이는 양서류(40.3%)'로 대안개념을 갖는 오류가 높게 나타났다. 그 이유는 분류 용어의 모호함으로 인한 혼동과 각 동물의 생리 생태적 특성을 분류 기준의 특성에 연계시키지 못하는 것에 있었다. 박쥐, 고래, 펭귄의 분류에서는 사회 문화적 요인이 오류의 빈도에 영향을 주었다. 동물 분류의 교수 학습이 암기 위주의 주입식보다는 관찰을 통한 분류 기준의 특성을 탐색하는 활동의 지도가 필요하다.

• 대한조선학회 특별논문집
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• 대한조선학회 2011년도 특별논문집
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• pp.12-16
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• 2011

During the shipbuilding construction, the repair works will be occurred by various reasons such as the natural disaster, mistakes of engineers or workers, defect of material, and so on. The one of the engineer's responsibilities is to design considering every possibility and to prevent the repair works due to the mistakes during construction stages, but actually it is very difficult and impossible to avoid every mistake. However, it is also the responsibility of engineers to find the best solution for the unavoidable mistakes which is to maintain the capacity of vessel and guarantee the safety for the repair works considering the construction schedules and economic cost. In this paper, it will be introduced the brief of repair works to the structural damage of the moon-pool structure in drillship which is built in our shipyard. For the verification of the structural strength, the fatigue analysis has been carried out based on the guide of Classification society. Furthermore, the modifications of structure design and welding procedure have been applied to avoid the stress concentration in the moon-pool structure.

• 한국안전학회지
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• 제33권1호
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• pp.66-72
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• 2018

This study analyses the types, related operations, facilities, and causes of chemical accidents in Korea based on the RISCAD classification taxonomy. In addition, human error analysis was carried out employing different human error classification criteria. Explosion and fire were major accident types, and nearly half of the accidents occurred during maintenance operation. In terms of related facility, storage devices and separators were the two most frequently involved ones. Results of the human error-based analysis showed that latent human errors in management level are involved in many accidents as well as active errors in the field level. Action errors related to unsafe behavior leads to accidents more often compared with the checking behavior. In particular, actions missed and inappropriate actions were major problems among the unsafe behaviors, which implicates that the compliance with the work procedure should be emphasized through education/training for the workers and the establishment of safety culture. According to the analysis of the causes of the human error, the frequency of skill-based mistakes leading to accidents were significantly lower than that of rule-based and knowledge based mistakes. However, there was limitation in the analysis of the root causes due to limited information in the accident investigation report. To solve this, it is suggested to adopt advanced accident investigation system including the establishment of independent organization and improvement in regulation.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2003년도 춘계학술대회논문집
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• pp.161-166
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• 2003

Semiconductor Manufacturing has emerged as one of the most Important world industries. Even with the highly automated and precisely monitored facilities used to process the complex manufacturing steps in a near particle free environment, processing variations in wafer fabrication still exist. The causes of these variations may arise from equipment malfunctions, delicate and difficult processing steps, or human mistakes. In this paper, we could specify the cause stage and the cause equipment and take countermeasures at a speed by the conventional method, without depending on the experience and skills of the engineer

• 한국시뮬레이션학회논문지
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• 제12권3호
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• pp.13-20
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• 2003

Semiconductor Manufacturing has emerged as one of the most important world industries. Even with the highly automated and precisely monitored facilities used to process the complex manufacturing steps in a near particle free environment, processing variations in wafer fabrication still exist. The causes of these variations may arise from equipment malfunctions, delicate and difficult processing steps, or human mistakes. In this paper, we could specify the cause stage and the cause equipment and take countermeasures at a speed by the conventional method, without depending on the experience and skills of the engineer

• 한국화재조사학회논문지
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• 제11권1호
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• pp.1-8
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• 2008

가스연료는 사업체, 가정 등에서 사용이 증가하고 있으며, 이로 인한 사고위험도도 증가추세 이며, 사고원인 또한 다양하게 나타나고 있다. 가스사고를 원인(취급부주의, 제품불량 등), 형태(화재, 폭발, 누출 등), 피해등급(1,2,3,4급), 사상자(사망, 중상, 경상)로 분류하여 설명하였다. 가스연료 중 가정에서 많이 사용되는 LP가스 시설은 가스용기, 압력조정기, 호스, 중간밸브, 연소기로 크게 구분할 수 있으며, 이 구성요소 중의 어떤 부분에서 취급부주의, 제품불량 등의 원인에 의해 화재 및 폭발 등이 발생할 수 있다. 따라서 사고 발생시 과거화재사례에 대한 연구 및 화재조사 시 착안사항을 참고하여 정확한 원인이 규명되어야 한다.

• 대한인간공학회지
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• 제32권1호
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• pp.9-16
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• 2013

Objective: The aim of this study is to investigate a trend of human error types observed in a series of verification and validation experiments for an Advanced Control Room(ACR) equipped with Lager Display Panel(LDP), Work Station Flat Panel Display(WS FPD), list type Alarm System(AS), Soft Control(SC) and Computerized Procedure System(CPS). Background: Operator behaviors in a fully computerized control room are quite different from those in a traditional hard-wired control room. Operators in an ACR all together monitor plant status and variables through their own interface system such as LDP and WS FPD, are notified of abnormal plant status through their own list type AS, control the plant through their own SC, and follow the structured procedure through their own CPS whereas operators in a traditional control room only separately do their duty directed by their supervisor. Especially the secondary task such as manipulating the user interface of ACR can be an extra burden to all the operators including the supervisor. Method: The Reason's human error classification method was applied to operators' behavioral data collected from a series of verification and validation experiments where operators showed their plant operational behaviors under a couple of harsh scenarios using the ACR simulator. Results: As operators accustomed to the new ACR system, knowledge or rule based mistakes appearing frequently in the early series of experiments decreased drastically in the latest stage of the series. Slip and lapse types of errors were observed throughout the series of experiments. Conclusion: Education and training can be one of the most important factors for the operators accustomed to the traditional control room to be adapted to the new system and to run the ACR successfully. Application: The results of this study implied that knowledge or rule based mistakes can be reduced by training and education but that lapse type errors might be reduced only through innovative improvement in human-system interface design or teamwork culture design including a new leadership style suitable for ACR.

• 대한인간공학회지
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• 제29권1호
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• pp.129-138
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• 2010

Gori-I nuclear power plant has been examining the effectiveness and efficiency of the current emergency operation procedures from human factors viewpoint. Previous study showed that some mistakes that the procedures did not comply with the writers' guidelines. Reviewing the current writers' guidelines for emergency operating procedures revealed that they lack of some important human factors rules such as enumeration of switching conditions and detailed action requirements, definite expression for setup points, description for anticipated results, and recommendation for use of present tense, affirmative sentence and active voice. This study suggested a new classification system for the writers' guideline contents supplementing the deficiencies of the current emergency operation procedure text.

• 한국멀티미디어학회논문지
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• 제22권3호
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• pp.349-356
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• 2019

When a prescription change occurs in the hospital depending on a patient's improvement status, pharmacists directly classify manually returned pills which are not taken by a patient. There are hundreds of kinds of pills to classify. Because it is manual, mistakes can occur and which can lead to medical accidents. In this study, we have compared YOLO, Faster R-CNN and RetinaNet to classify and detect pills. The data consisted of 10 classes and used 100 images per class. To evaluate the performance of each model, we used cross-validation. As a result, the YOLO Model had sensitivity of 91.05%, FPs/image of 0.0507. The Faster R-CNN's sensitivity was 99.6% and FPs/image was 0.0089. The RetinaNet showed sensitivity of 98.31% and FPs/image of 0.0119. Faster RCNN showed the best performance among these three models tested. Thus, the most appropriate model for classifying pills among the three models is the Faster R-CNN with the most accurate detection and classification results and a low FP/image.