• 제목/요약/키워드: Investigation technique

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마이크로/나노 비파괴평가 기술(I): 표면 및 표면직하 검사 (Review of Micro/Nano Nondestructive Evaluation Technique (I): Surface and Subsurface Investigation)

  • 김정석;박익근
    • 비파괴검사학회지
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    • 제32권2호
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    • pp.198-209
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    • 2012
  • 본 논문은 널리 사용되고 있는 표면 미세조직 검사 기술과 표면 및 표면직하의 평가가 가능한 마이크로/나노 비파괴평가 기술을 소개한다. 일반적으로 재료 표면에서의 마이크로/나노 결함과 조직 상태는 벌크재료의 기계적, 물리적, 화학적 특성에 크게 영향을 주게 된다. 표면 미세조직 검사 기술은 이러한 재료의 결함과 조직특성을 신뢰도 높게 평가하는 기술이다. 각 검사기술의 원리와 특징, 응용분야와 개발 등을 소개하였다. 따라서 비파괴산업에서 마이크로/나노 비파괴평가의 적용과 기술 개발이 폭넓게 가능할 것으로 판단된다.

에너지 절약기술 이전ㆍ도입 실태조사 연구 (Investigation Analysis for Transfer & induction of Energy Conservation Technology)

  • 이상설;이덕기;박수억
    • 에너지공학
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    • 제13권1호
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    • pp.40-50
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    • 2004
  • Treatise that see executed investigation analysis about energy conservation technology, which skill move and skill class of introduction subject, transferㆍintroduction skill form, present condition of technology transferㆍintroduction and necessity etc. to energy conservation technology by program of Korea energy basis plan (1997∼2006) etc. Enforced company which questionnaire object achieves from the end 107 assignment practical used of energy conservation technology development propulsion assignment of Korea energy management corporation (KEMCO) to 1998-200 years and 416 companies related energy saving technology constructed to Korea Institute of Energy Research (KIER) database by post investigation and visit investigation. Question investigation result, transferㆍintroduction fields of energy conservation technology are industry sector, the enterprise size appeared with the fact that the small and medium enteifrise is many most. Also, technology transferㆍintroduction section is plan technique, form with technical cooperative form, amount of money 50,000,000 won under, appeared above 1 years in disturbance duration. In hereafter, technology transferㆍintroduction plan it appeared with the fact that the plan technique is many most.

산업현장에서 쉽게 적용할 수 있는 근본원인 사고조사기법 개발에 관한 연구 (Development of RCA Incident Investigation Method as Easily Adopted Industry Field)

  • 권재범;권영국
    • 한국안전학회지
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    • 제36권5호
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    • pp.43-51
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    • 2021
  • Incident investigation is one of the most important processes among various other safety management methods to prevent industrial accidents. Finding the root causes of accidents, eliminating hazards, and improving safety are the most important purposes of investigating accidents. During the investigation process, root cause analysis (RCA) techniques are used to effectively identify RCA. Over the past few decades, over 30 RCA methods have been developed. These techniques are being widely used in some industries, such as the nuclear and aircraft industries; however, most of the RCA techniques require professional knowledge and special training, making it difficult for safety managers in their respective fields to understand and apply them. Therefore, managers of general industrial sites are rarely present at the scene of actual accident investigations, and they cannot contribute much to the purpose and effectiveness of these investigations. In this study, to address these issues, we developed an RCA technique to facilitate root cause investigation of accidents in real-world industrial sites. To develop new techniques, Systematic Cause Analysis Technique (SCAT), one of the RCA techniques, was used to investigate incidents in the enterprise over three years. We also utilized feature analysis and other papers from existing RCA techniques. To verify its effectiveness, the technique proposed was also applied to the accident case. The technique developed can easily identify and analyze the root cause of an accident and help industrial managers. It can also identify the root cause category where accidents are concentrated and use this data to establish guidelines for preventing future accidents and, thus, focus on prioritizing improvement initiatives.

도심지 지반 전단파속도 탐사를 위한 P-파 속도와 전기비저항의 이종 결합 (Hybrid Integration of P-Wave Velocity and Resistivity for High-Quality Investigation of In Situ Shear-Wave Velocities at Urban Areas)

  • 조성호;김봉찬
    • 대한토목학회논문집
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    • 제30권1C호
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    • pp.45-51
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    • 2010
  • 지하철 터널 시공, 지하공간 시공, 대심도 굴착 등과 같이 도심지에서의 토목구조물 설계와 시공에 있어서 큰 어려움 중의 하나는 도심지 지반조사이다. 여러 가지 지장물, 전기 잡음, 교통 진동 등과 같은 자연적, 인위적 장애물로 인하여 어느 지반조사 기법이든지 그 결과의 신뢰성은 그리 높지 않은 상황이다. 본 연구에서는 이와 같이 현실적 요구가 높은 고품질 도심지 지반조사 기법의 개발을 목표로 하여 선행연구를 수행하였고, 일차적으로 HiRAS(Hybrid Integration of Resistivity and Surface Wave Velocities) 라고 하는 표면파-전기비저항 병합기법을 개발하였다. HiRAS 기법은 표면파 기법인 CapSASW 기법과 전기비저항 기법인 PDC-R 기법을 병합한 것으로서, 지반 매질의 강성 평가에 우수한 CapSASW 기법의 장점과, 전기잡음에 대한 내성과 지층변화 평가에 우수한 특성을 가진 PDC-R 기법의 장점을 동시에 활용하고자 한 것이다. 표면파 기법과 전기비저항 기법을 동시에 활용하는 역산해석의 측면에서는 표면파 기법의 탄성파 속도와 전기비저항 시험의 전기비저항 간의 부지고유관계를 이용하여 병합역산을 수행하는 전략을 채택하였다. 또한 HiRAS 기법 개발과정에서 부차적으로 지반매질의 포아송비 분포를 2차원으로 평가할 수 있는 성과도 도출하였다.

고도 정밀 M&S 시스템을 이용한 해난사고 원인규명 (Marine Accident Cause Investigation using M&S System)

  • 이상갑
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2014년도 춘계학술대회
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    • pp.36-37
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    • 2014
  • It is necessary to develop highly sophisticated Modeling & Simulation (M&S) system for the scientific investigation of marine accident causes and for the systematic reproduction of accidental damage procedure. To ensure an accurate and reasonable prediction of marine accidental causes, such as collision, grounding and flooding, full-scale ship M&S simulations would be the best approach using hydrocode, such as LS-DYNA code, with its Fluid-Structure Interaction (FSI) analysis technique. The objectivity of this paper is to present three full-scale ship collision, grounding and flooding simulation results of marine accidents, and to show the possibility of the scientific investigation of marine accident causes using highly sophisticated M&S system.

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ADINA FSI를 활용한 원심주조기 폭발사고 원인 규명에 관한 법공학적 연구 (Forensic Engineering Study on the Explosion Accident Investigation of the Centrifugal Casting Machine Using ADINA FSI)

  • 김의수;김종혁;김무곤
    • 한국안전학회지
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    • 제26권4호
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    • pp.27-33
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    • 2011
  • Forensic Engineering is the area covering the investigation of products, structures that fail to perform or do not function as intended, causing personal injury or damage to property. To investigate explosion accident of the centrifugal casting machine in terms of the forensic engineering, in this paper, the computing simulation using ADINA FSI has performed to investigate that the effect of the Check-Pin fracture by the flow phenomena and molten metal weight and the mechanical properties test of the accident Check-Pin has performed using the instrumented indentation technique. Through these studies, the safety accident that may occur in centrifugal casting machine can be minimized by performing specialized and systematic investigation of the accident cause in terms of the forensic engineering.

A New Random PWM Technique for Conducted-EMI Mitigation on Cuk Converter

  • Krishnakumar, C.;Muhilan, P.;Sathiskumar, M.;Sakthivel, M.
    • Journal of Electrical Engineering and Technology
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    • 제10권3호
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    • pp.916-924
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    • 2015
  • Electromagnetic Interference (EMI) is a system to system or environment to system phenomenon. The literature survey proved that the Randomized Pulse Width Modulation (RPWM) technique is a promising technique to reduce EMI. A new Constant Trailing Edge, Randomized Pulse Width Modulation (CTERPWM) technique is proposed in this paper. The effect of the proposed RPWM technique for mitigation of conducted-EMI on Cuk converter operating in Continuous Conduction Mode (CCM) is simulated and tested. In this paper, the analytical expressions for the Power Spectral Density (PSD) are derived for the proposed RPWM technique and are validated by experimental measurements. The effectiveness of the proposed RPWM technique on the mitigation of conducted-EMI is verified comparing simulation and experimental results and it is identified that both the results are almost similar with allowable experimental deviations. The comparative investigation proves that the proposed RPWM technique can mitigate and spread the dominant peaks of conducted-EMI over the complete spectrum for the Cuk converter. Based on the investigation the CTERPWM technique is recommended for adoption.

디지털 포렌식 조사에서 효율적인 파일 복구를 위한 레코드 파일 카빙 기법 (Record File Carving Technique for Efficient File Recovery in Digital Forensic Investigation)

  • 박민수;박정흠;이상진
    • 정보처리학회논문지:컴퓨터 및 통신 시스템
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    • 제2권2호
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    • pp.93-102
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    • 2013
  • 최근 대부분의 범죄에 디지털 매체가 사용되면서 디지털 데이터는 필수 조사 대상이 되었다. 하지만 디지털 데이터는 비교적 쉽게 삭제 및 변조가 가능하다. 따라서 디지털 증거 획득을 위해 삭제된 데이터의 복구가 필요하며, 파일 카빙은 컴퓨터 포렌식 조사에서 증거를 획득할 수 있는 중요한 요소이다. 하지만 현재 사용되는 파일 카빙 도구들은 포렌식 조사를 위한 데이터의 선별을 고려하지 않고 있다. 또 기존의 파일 카빙 기법들은 파일의 일부 영역이 덮어써지거나 조각날 경우 복구가 불가능한 단점이 있다. 따라서 본 논문에서는 포렌식 조사시 유용한 정보를 획득할 수 있는 파일을 제안하고, 기존의 파일 카빙 기법보다 효과적으로 데이터를 복구할 수 있는 레코드 파일 카빙 기법을 제시한다.

3차원 가시화 기법을 이용한 터널설계 (3D Visualization Technique Based Tunnel Design)

  • 홍성완;배규진;김창용;서용석;김광염
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2002년도 봄 학술발표회 논문집
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    • pp.759-766
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    • 2002
  • In the paper the authors describe the development of ITIS(Intelligent Tunneling Information System) for the Purpose of applying the 3D visualization technique, GIS, AI(Artificial Intelligence) to tunnel design and construction. VR(Virtual Reality) and 3D visualization techniques are applied in order to develope the 3D model of characteristics and structures of ground and rock mass. Database for all the materials related to site investigation and tunnel construction is developed using GIS technique. AI technique such as fuzzy theory and neural network is applied to predict ground settlement, decide tunnel support method and estimate ground and rock mass properties according to tunnel excavation steps. ITIS can help to inform various necessary tunnel information to engineers quickly and manage tunnel using acquired information based on D/B.

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