• 문화기술의 융합
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• 제10권2호
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• pp.505-510
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• 2024

철도 레일은 차륜과 레일의 접촉면인 레일 표면에서 구름 접촉 피로 균열이 상시 발생할 수 있는 조건이기 때문에 균열의 상태를 철저히 점검하고 절손을 방지하기 위한 정밀한 점검 및 진단이 필요하다. 최근 궤도 시설의 성능 평가에 대한 세부 지침에서는 궤도 성능평가를 위한 방법과 절차에 관한 필요사항을 제시하고 있다. 그러나 레일 표면 손상을 진단하고 등급을 산정하는 것은 주로 외관 조사(육안 조사)에 의존하며, 이는 점검자의 주관적인 판단에 따른 정성적인 평가에 의존할 수밖에 없는 실정이다. 따라서 본 연구에서는 Fast R-CNN을 사용하여 레일 표면 결함 검출에 대한 딥러닝 모델 연구를 수행하였다. 레일 표면 결함 이미지의 데이터 세트를 구축한 후, 모델을 테스트하였다. 딥러닝 모델의 성능평가 결과에서 mAP가 94.9%로 나타났다. Fast R-CNN의 균열 검출 효과가 높기 때문에 이 모델을 사용하면 레일표면 결함을 효율적으로 식별할 수 있을 것으로 판단된다.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2004년도 제5회 정기학술발표대회 논문집
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• pp.552-555
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• 2004

최근에는 고층화, 대형화, 복잡한 구조물의 축조가 현격히 증가하여 철골공사는 지속적으로 증가할 것으로 예상됨으로 철골공사에서 재해 발생은 지속적으로 늘어나고 있는 실정이다. 건설현장에서는 사전작업절차서, 안전관리계획서, 시공계획서, 점검일지를 통하여 작업의 위험요소를 파악하고 관리하는 안전점검 활동이 이루어지고 있으나 이와 같은 계획서에는 세부적인 작업의 수준으로 작성되지 않고 적응범위가 미흡하여 건설현장에서 활용도가 저조한 실정이다. 안전관리 체크리스트를 체계적으로 작성하기 위해서는 세부적인 작업에 관하여 재해원인을 파악해야 한다. 본 연구에서 안전관리 방안을 위한 재해유형의 원인은 전체 건설공사 중에서 철골공사를 그 대상으로 하고 있다. 철골공사작업에서의 안전사고를 예방하기 위하여 철골공정을 세부작업으로 나누어, 차후에 체크리스트를 개발하기 위해 각 세부작업에 관한 재해 원인을 파악하고자 한다.

• Journal of Advanced Marine Engineering and Technology
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• 제34권8호
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• pp.1222-1229
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• 2010

비선형 측심기를 이용한 초고해상 음향탐사는 기존의 고해상 음향탐사보다 투과력은 작지만 해상력이 뛰어나기 때문에 천해역에서의 해저환경조사에 유용하게 사용된다. 비선형 지층탐사 시스템은 정확한 수심측정 뿐 아니라 퇴적층과 하부구조에 대한 상세한 정보를 제공한다. 특히 상부 퇴적층의 정밀층후 및 퇴적구조 확인을 통해 해저에 파묻혀 있는 pipeline, 침몰선박, 인위적 물체 등에 대한 탐색에 이용된다. 이 연구에서는 초고해상 지층탐사기를 이용하여 얻어진 지층탐사 기록과 지질자료를 대비하여 오염퇴적층을 구분하였다. 그리고 지층 기록에 나타나는 음향이상을 해석하여 해저에 매설된 케이블의 매설 깊이를 검측하였다.

• 한국공작기계학회논문집
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• 제16권2호
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• pp.92-99
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• 2007

Welding fabrication invariantly involves three district sequential steps: preparation, actual process execution and post-weld inspection. One of the major problems in automating these steps and developing autonomous welding systems, is the lack of proper sensing strategies. Conventionally, machine vision is used in robotic arc welding only for the correction of pre-taught welding paths in single pass. In this paper, novel presented, developed vision processing techniques are detailed, and their application in welding fabrication is covered. The software for joint tracking system is finally proposed.

• Journal of Chest Surgery
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• 제25권10호
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• pp.1087-1092
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• 1992

We underwent two surgical resection of synchronous primary esophageal squamous cell carcinoma and gastric adenocarcinoma after obtaining histologic comfirmation 74-years old male pateint was recieved esophagectomy & total gastrectomy with esophagojejunostomy and 59-years old man was recieved near total esophagectomy and total gastrectomy with esophagocolo-gejunostomy. Their was no postoperative complications. The hospital day was 15 and 21 days postoperatively. All of them started oral intake at 7 days postoperatively and possible soft diet soon. We conclude that total resection of esophagus and stomach is the recommendable methods for prolong the life of double primary cancer patients of esophagus and stomach. Also, the reconstruction of the esophagus with colon or jejunal transposition is one of the recommenable procedure for curative surgical resection of double primary cancer in esophagus and stomach. And we also wish to emphasize the importance of detailed preopertive gastric examination for detect of gastric lesion and of careful intraoperative inspection of the gastric mucosa in patients with esophageal cancer whose preoperative gastric examination provide inconclusive evidence due to the severe esophageal stenosis.

• Earthquakes and Structures
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• 제11권5호
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• pp.873-885
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• 2016

Determination of earthquake-safety of existing buildings requires a rather long and challenging process both in terms of time and expertise. In order to prevent such a tedious process, rather rapid methods for evaluating buildings were developed. The purpose of these rapid methods is to determine the buildings that have priority in terms of risk and accordingly to minimize the number of buildings to be inspected. In these rapid evaluation methods detailed information and inspection are not required. Among these methods the Canadian Seismic scanning method and the first stage evaluation method included in the principles concerning the determination of risk-bearing buildings promulgated by the Ministry of Environment and Urbanization in Turkey are used in the present study. Within the scope of this study, six reinforced concrete buildings damaged in Van earthquakes in Turkey are selected. The performance scores of these buildings are calculated separately with the mentioned two methods, and then compared. The purpose of the study is to provide information on these two methods and to set forth the relation they have between them in order to manifest the international validity.

• 한국멀티미디어학회논문지
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• 제20권4호
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• pp.660-670
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• 2017

In case of auditing of the information system development project applying agile methodology, it is not appropriate to carry out a comprehensive check on the establishment of information system with only the existing check on software. This study considers the characteristics of the agile methodology in terms of Information System Auditing. To improve inspection quality of development project with agile methodology by deriving detailed check items of test activities at each stage, this study proposes a strategy to improve the check on software for the test activities of the supervisory model that is suitable for agile methodology, which emphasizes repetitive work.

• 대한기계학회논문집A
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• 제28권3호
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• pp.311-317
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• 2004

This paper proposes engineering estimation equations for the maximum deflection of a cylinder subject to bending under elastic-plastic and elastic-creep conditions. Being based on the reference stress approach, the proposed equations are simple to use and can accommodate general tensile and creep behaviours. Validation against detailed 3-D FE results using actual stress-strain data and realistic creep-deformation data shows excellent agreement, which provides confidence in the use of the proposed equation. Based on the proposed equations, together with information on in-service inspection data, discussion is given how to estimate future time-dependent and time-independent deflection of the CANDU pressure tube. Thus the present result would be valuable information for integrity assessment of the CANDU pressure tube.

• 방사성폐기물학회지
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• 제18권3호
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• pp.347-354
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• 2020

Site characterization for decommissioning Kori Unit 1 is ongoing in South Korea after 40 years of successful operation. Kori Unit 1's containment building is assumed to be mostly radioactively contaminated, and therefore radiation exposure management and detailed contamination investigation are required for decommissioning and dismantling it safely. In this study, site-specific Derived Concentration Guideline Levels (DCGLs) were derived using the residual radioactivity risk evaluation tool, RESRAD-BUILD code. A conceptual model of containment building for Kori Unit 1 was set up and limited occupational worker building inspection scenario was applied. Depending on the source location, the maximum contribution source and exposure pathway of each radionuclide were analyzed. The contribution of radionuclides to dose and exposure pathways, by source location, is expected to serve as basic data in the assessment criteria of survey areas and classification of impact areas during further decommissioning and decontamination of sites.

• 항공우주시스템공학회지
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• 제3권1호
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• pp.6-11
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• 2009

It is anticipated that quality assurance for the Ka band Communication Payload System(COPS) development program of the communication, Ocean & Meteorological Satellite(COMS) may be a core technical factor to be concerned in order to avoid any failure, and to assure its final performance during the mission lifetime in space. Those can be managed and verified and assessed by performing the Quality Assurance (QA) and risk management which helps to prevent and to reduce the critical fails. This paper introduces the Product Assurance (PA) system and procedures for controlling and monitoring sub-contractors which were participated in Ka band Communication Payload System (COPS) development. Also this paper shows Quality Assurance (QA) procedures and detailed their processes for assured the product performed by local companies from site survey for selecting companies to delivery of their equipment.