• 제목/요약/키워드: leakage problems

검색결과 545건 처리시간 0.023초

효과적인 강자성체 평판구조물 검사를 위한 전 방향 전단파 자기변형 패치 트랜스듀서 개발 (Development of an omni-directional shear-horizontal wave magnetostrictive patch transducer for the effective inspection of a ferromagnetic plate)

  • 승홍민;김윤영
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2014년도 추계학술대회 논문집
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    • pp.548-549
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    • 2014
  • Omni-directional shear-horizontal magnetostrictive patch transducers have a disadvantage that magnetic flux leakage into the plate when it is installed on a ferromagnetic plate. The leakage produces poor transduction efficiency and unwanted wave mode excitation which should be avoided in guided wave inspections of large plate-like structures. In order to resolve these problems, we newly developed a method to reduce the leakage into the plate. In the method, the patch and the magnet are vertically lifted off and their optimal positions are determined by numerical simulations. Also, the verification of the developed method is successfully verified by experiments.

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엔진 배기매니폴드의 배기가스 누설 해석 (Leakage Analysis of the Exhaust Gas for the Engine Exhaust Manifold)

  • 최복록
    • 한국자동차공학회논문집
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    • 제15권3호
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    • pp.160-165
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    • 2007
  • Exhaust manifold is generally subjected to thermal cycle loadings ; at hot condition, large compressive plastic deformations are generated, and at cold condition, tensile stresses are remained in highly deformed critical zones. These phenomena originate from that thermal expansions of the runners are restricted by inlet flange connected to the cylinder head, because the former is less stiff than the latter and, the temperature of the inlet flange is lower than that of the runners. Therefore, due to the repetitions of thermal deformation, leakage problems could be occur between inlet flange and cylinder head. In this study, we obtained pressure distributions along gasket bead lines from the finite element analysis and compared to the test results. It shows a good agreement between numerical and experimental results.

유류성분이 지하구조물의 방수층 손상에 미치는 영향에 관한 실험적 연구 (An Experimental Study on the Damage of Waterproofing Membrane due to Oil ingredient of Underground Structures)

  • 송제영;강효진;곽규성;오상근
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2006년도 춘계학술논문 발표대회 제6권1호
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    • pp.177-180
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    • 2006
  • The accidents of oil leakage is increasing in the Underground Concrete structures for Oil Storege. In the result, the waterproofing in the underground structures is melt down and cannot fulfil its Performance. This study shows an experimental study in the effects of the oil leakage to on the performance of Waterproofing Materials. In order to investigate the actual condition and the problems, a comparative analyses were conducted considering the various types of leakage. Utilizing the obtained results at the basic data for test methods and the standard of quality, we intended to propose a strategy to develop an innovated waterproofing Materials and improve the clean environment of underground structures.

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국내 공동주택의 지하공간 방수설계 및 시방기준 (Domestic Below-Grade Waterproofing Design and Specification Standard for Residential Apartments)

  • 이정훈;최은규;송제영;김수연;오상근
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2018년도 추계 학술논문 발표대회
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    • pp.185-186
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    • 2018
  • Leakage problems in underground spaces of domestic apartments is becoming more serious and legal disputes related to leakage problem have become more commonplace. In this regard, leakage problem is not only a problem in construction, but is also a concern from a societal aspect. In this paper, we propose the details of a below-grade waterproofing design and specification standards of specific areas and sections of residential apartment buildings, and propose that a detailed examination of positive-side waterproofing methods is required.

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누수예방을 위한 품질확보 관련 정보공유시스템의 활용방안의 관한 연구 (Information Network Usage Plan for the Quality Control of Leakage Prevention)

  • 강효진;안기원;김수련;오상근
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2017년도 추계 학술논문 발표대회
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    • pp.217-218
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    • 2017
  • Residential apartment underground structures are being utilized for many purposes such as parking lots, community centers, fitness centers, etc. for efficient use of space. However, there are increasing problems of leakage due to various environmental and deterioration conditions. This paper proposes the development of an information network system which can serve as a base to provide solutions, alternatives and technical information for leakage prevention and effective design at the beginning of the construction stage.

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New Security Layer for OverLay Networks

  • Imai, Hideki;Shin, Seong-Han;Kobara, Kazukuni
    • Journal of Communications and Networks
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    • 제11권3호
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    • pp.211-228
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    • 2009
  • After clarifying the underlying problems in a secure network storage, we introduce two important requirements, leakageresilience and availability in higher levels respectively, for data keys that are used to protect remotely-stored data. As a main contribution of this paper, we give a new security layer for overlay networks by proposing a leakage-resilient authentication and data management system. In this system, we specifically propose a single mode and a cluster mode where the latter provides a higher level of both leakage-resilience and availability for the data key.

격납건물 ILRT 본시험시간이 시험에 미치는 영향에 관한 연구 (A Study on the Effect of Integrated Leakage Rate Testing of Containment Vessel due to the Type A Testing Time)

  • 김창수;문용식
    • 한국압력기기공학회 논문집
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    • 제8권3호
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    • pp.1-6
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    • 2012
  • The containment Integrated Leakage Rate Testing(ILRT) of nuclear power plants in Korea is performed in accordance with NSSC(Nuclear Safety and Security Commission) code 2012-16 and ANSI/ANS 56.8-1994. Nuclear power plants in Korea and the United States are to apply same test criteria, ANSI/ANS 56.8-1994, except type A testing time. NPPs in Korea apply 24 hours according to NSSC code 2012-16, but NPPs in United States apply 8 hours according to 10CFR50 App. J for type A test. So, there are many difficulties in order to perform ILRT in Korea. In this study, I review the impact on the ILRT results and the effect of ILRT due to type A testing time. The future, we will continue study to enhance the test reliability and improve these problems.

원전 내 배관의 증기 누설 사고 시 누설 탐지 포집/이송 시스템 예비 해석 (Preliminary Analysis of a Sampling and Transportation System for Leak Detection during Steam Leak Accident of a Pipe in Nuclear Power Plants)

  • 최대경;최청열;권태순;어동진
    • 한국압력기기공학회 논문집
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    • 제16권2호
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    • pp.25-34
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    • 2020
  • As leakage in nuclear power plants could cause a variety of problems, it is very critical to monitor leakage from the safety point of view. Accordingly, a new type of leak detection system is currently being developed and flow characteristics of the sampling and transportation system are investigated by using numerical analysis as a part of the development process in this study. The results showed that the steam mass fraction varied according to the effect of the gap between the insulation and piping component, transportation velocity, and material properties of porous media during the sampling and transportation process. The results of this study should be useful for understanding flow characteristics of the sampling and transportation system and its design and application.

개인정보유출 피해 비용 산출 모델에 관한 연구 (A Study on the Damage Cost Estimation Model for Personal Information Leakage in Korea)

  • 임규건;류미나;이정미
    • 정보보호학회논문지
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    • 제28권1호
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    • pp.215-227
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    • 2018
  • 한국은 단기간에 IT강국으로 급성장함에 따라 사이버 폭력, 개인정보 유출, 사이버 테러 등 사이버상의 각종 부작용이 새로운 사회적 문제로 대두되고 있다. 특히 안전한 사이버 생활의 기본이 되는 개인정보 유출에 대한 심각성은 전 세계적으로 심각한 문제로 부각되고 있다. 이와 관련하여 개인정보 유출에 따른 피해비용 규모의 추정이 필요한데 이와 관련한 연구는 국내에서는 아직 미흡한 상황이다. 이에 본 연구에서는 개인정보 유출에 따른 피해비용 산출 모델을 실거래 평균값 기반, 개인 인식 가치 기반, 보상금액 기반, 타 국가 기반의 네 가지 방식을 제시한다. 그리고, 2007년부터 2016년까지의 뉴스와 보고서 등의 자료를 분석하여 10년간의 개인정보 유출사건을 수집하여 피해비용을 추정하였다. 추정에 활용한 사건의 수는 65건이고 총 개인정보 유출 건수는 약 4억 3천만 건에 이른다. 추정결과 2016년의 개인정보 유출로 인한 피해비용은 최소 74억에서 최대 220조로 추산되었으며 10개년도 평균은 연간 약 107억에서 307조로 추산 되었다. 또한 개인정보 유출로 인한 추정 피해액이 3년 주기로 상승하는 특이점을 발견할 수 있었다. 앞으로 본 연구를 통해 개인정보 유출로 인한 피해비용을 조금 더 정확하게 측정할 수 있는 지표를 마련하고 그 피해비용을 줄일 수 있는 방안 마련의 지표로 사용되기를 기대한다.

모바일 환경에서 개인정보 유출 방지를 위한 개선 연구 (The Study of Improvement of Personal Information Leakage Prevention in Mobile Environment)

  • 최희식;조양현
    • 디지털산업정보학회논문지
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    • 제11권3호
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    • pp.53-62
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    • 2015
  • Recently, number of tablet or Smartphone users increased significantly in domestic and around the world. But violation of personal information such as leakage, misuse and abuse are constantly occurring by using mobile devices which is very useful in our society. Therefore, in this paper it will talk about the problems in the network environment of the mobile environment such as tablet and Smartphone, Mobile Malware, hacking of the public key certificate, which could be potential threat to mobile environment. This thesis will research for people to use their mobile devices more reliable and safer in mobile environment from invasion and leakage of personal information. In order to use Smartphone safely, users have to use Wi-Fi and Bluetooth carefully in the public area. This paper will research how to use App safely and characteristic of risk of worm and Malware spreading. Because of security vulnerabilities of the public key certificate, it will suggest new type of security certification. In order to prevent from the information leakage and infect from Malware in mobile environment without knowing, this thesis will analyze the improved way to manage and use the mobile device.