• Journal of Welding and Joining
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• v.28 no.4
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• pp.14-17
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• 2010

• Journal of Welding and Joining
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• v.18 no.3
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• pp.32-40
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• 2000

• Journal of Welding and Joining
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• v.13 no.1
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• pp.51-61
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• 1995

품질보증 활동은 제품의 품질등급을 그 규격기준에 따라 규정하고, 발주자가 지정하는 품질의 제품을 실현하는 것이지만, 압력용기 등의 특정 제품에 대해서는 공적인 제3자가 기관에 의한 검사 인증제도가 요구되는 경우가 있다. 미국에서는 압력용기 등의 규격체계는 민간 Base의 ASME Code를 중심으로 하고, 운용에 있어서의 품질보증제도는 ASME Stamp에 의한 제작공장 인증과 적검사기관을 대행하는 보험회사와의 협조에 의한 개별제품인증이 행해진다. 소위 체제 지향의 품질 관리방식을 채택하고 있다. 미국 외의 구라파제국의 이와는 상대적으로 제품지향의 제품질관리를 하였다고 할 수가 있다. 그러나 87년에 제정되어 세계적으로 확산되고 있는 ISO-9000 시리즈는 미국식의 체제지향의 품질관리로서 양자간 접근방식이 대동소이하다. 그러므로 ASME Code의 품질관리에 대하여 그 본질과 구조 및 활동 내역 등을 고찰해 보는 것은 품질관리의 시대적 조류 파악에 도움이 될 것이다.

• Journal of Korean Society of Steel Construction
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• v.11 no.1 s.38
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• pp.1-11
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• 1999

The aim of this study is to construct a machine vision monitoring system for an automatic visual inspection of weld joint in steel structure. An image processing algorithm for a visual weld defects detection on weld bead is developed using the intensity image. An optic system for getting four intensity images was set as a fixed camera position and four different illumination directions. The input images were thresholded and segmented after a suitable preprocessing and the features of each region were defined and calculated. The features were used in the detection and the classification of the visual weld defects. It is confirmed that the developed algorithm can detect weld defects that could not be detected by previously developed techniques. The recognized results were evaluated and compared to expert inspectors' results.

• Proceedings of the KWS Conference
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• 2009.11a
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• pp.5-5
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• 2009

용접에 의한 이면부 도장의 Burn damage는 관리하기 힘든 고질적인 품질문제이다. 도장면의 Burn damage 품질문제 발생시 재작업 등으로 인하여 많은 비용이 발생한다. 이런 경우 기존에 보유한 실험자료 및 적절한 이론자료 부족으로 인하여 일회적인 실험 혹은 해석적 방법을 사용하여 용접 이면부의 최고온도 등을 예측하고 회피할 수 있는 방법론을 제공하였다. 그러나 각 경우에 대해 해석 및 실험을 진행하게 되면 시간 및 비용에서 많은 문제점을 일으키게 된다. 따라서 체계적이고 효율적인 Burn damage 예측방법의 필요성이 대두되었다. 본 연구의 목적은 실험적/해석적 방법을 통해 용접이면부 최고 온도를 예측하고 이를 통해 일반화된 용접이면부 최고도달온도 예측식을 유도하는 것에 있다. 이를 위해 다양한 조건에서의 실험과 해석을 실시하였으며 이를 통해 일반화된 용접 이면부 최고도달온도 예측식을 유도하였다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.2
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• pp.193-201
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• 2021

The welding has a high proportion of the production and drying of ships or offshore plants. Non-destructive testing is carried out to verify the quality of welds in Korea, radiography test (RT) is mainly used. Currently, most shipyards adopt analog-type techniques to print the films through the shoot of welding parts. Therefore, the time required from radiography test to pass or fail judgment is long and complex, and is being manually carried out by qualified inspectors. To improve this problem, this paper covers a platform for scanning and digitalizing RT films occurring in shipyards with high resolution, accumulating them in management servers, and applying artificial intelligence (AI) technology to detect welding defects. To do this, we describe the process of designing and developing RT film scanning equipment, welding inspection information integrated management platform, fault reading algorithms, visualization software, and testing and verification of each developed element in conjunction.

• Journal of the Korean Professional Engineers Association
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• v.33 no.6
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• pp.57-60
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• 2000

• Journal of the Korean Professional Engineers Association
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• v.33 no.5
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• pp.59-64
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• 2000

This improvement case to be introduced of all welders, welding operator, tack welders and welding inspector for reducing of welding defect rate and good quality.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.9
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• pp.1081-1086
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• 2012

This study deals with hardness evaluation for spot welding by using an instrumented indentation technique to improve the quality of the inspection methodology. First, an instrumented indentation test and a Rockwell hardness test were performed for normal and abnormal spot welding. The hardness to indentation force-displacement curve obtained using each of the tests was compared. Furthermore, an analysis was conducted using the hardness obtained by the instrumented indentation technique. A quality control standard based on reliability was this evaluated for spot welding.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.6
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• pp.2859-2865
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• 2011

The welded connection is known as an essential factor for establishing qualified construction and/or maintenance of wrapped steel pipe. In this study, welded connection conditions in the coated pipes with large diameter (over 700 mm) in Korea water distribution systems were estimated for suggesting technically and economically available welded connection method. For the study analysis, current steel pipe usage and accident cases were investigated. In addition, the characteristics of each welded connection method and automatic or manual connection techniques were also compared and estimated. As results, automatic welded connection method is superior than manual welded connection method in aspect of pure construction cost (average 9%) or pure welded connection cost (average 13.5%). When the poor welding-working situations in Korea are considered such as high tolerance of out-of-roundness in KS regulation, a number of lap joint welded connections, the real cost benefits of automatic welded connection should be much higher than those of manual welded connections.