• Title/Summary/Keyword: Investigation technique

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

  • Kim, Chung-Seok;Park, Ik-Keun
    • Journal of the Korean Society for Nondestructive Testing
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    • v.32 no.2
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    • pp.198-209
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    • 2012
  • The present paper reviews the widely used surface microstructural investigation technique and micro/nano nondestructive evaluation(NDE) technique which is able to evaluate the surface and subsurface. In general, the micro/nano defects and microstructural state of surface have great influence on the mechanical, physical, and chemical properties of bulk materials. The investigation technique of surface microstructure is possible to evaluate the defects and microstructural state with high reliability. The various applications and developments of each inspection technique have been introduced. Consequently, it is thought that the technique developments and applications of micro/nano NDE in nondestructive industries are extensively possible hereafter.

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

  • 이상설;이덕기;박수억
    • Journal of Energy Engineering
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    • v.13 no.1
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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.

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

  • Kwon, Jae Beom;Kwon, Young Guk
    • Journal of the Korean Society of Safety
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    • v.36 no.5
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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.

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

  • Joh, Sung-Ho;Kim, Bong-Chan
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.30 no.1C
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    • pp.45-51
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    • 2010
  • In urban area, design and construction of civil engineering structures such as subway tunnel, underground space and deep excavation is impeded by unreliable site investigation. Variety of embedded objects, electric noises and traffic vibrations degrades the quality of site investigation, whatever the site-investigation technique would be. In this research, a preliminary research was performed to develop a dedicated site investigation technique for urban geotechnical sites, which can overcome the limitations of urban sites. HiRAS (Hybrid Integration of Surface Waves and Resistivity) technique which is the first outcome of the preliminary research was proposed in this paper. The technique combines surface wave as well as electrical resistivity. CapSASW method for surface-wave technique and PDC-R technique for electrical resistivity survey were incorporated to develop HiRAS technique. CapSASW method is a good method for evaluating material stiffness and PDC-R technique is a reliable method for determination of underground stratification even in a site with electrical noise. For the inversion analysis of HiRAS techniuqe, a site-specific relationship between stress-wave velocity and resistivity was employed. As for outgrowth of this research, the 2-D distribution of Poisson's ratio could be also determined.

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

  • Lee, Sang-Gab
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2014.06a
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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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Forensic Engineering Study on the Explosion Accident Investigation of the Centrifugal Casting Machine Using ADINA FSI (ADINA FSI를 활용한 원심주조기 폭발사고 원인 규명에 관한 법공학적 연구)

  • Kim, Eui-Soo;Kim, Jong-Hyuk;Kim, Moo-Gon
    • Journal of the Korean Society of Safety
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    • v.26 no.4
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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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    • v.10 no.3
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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.

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

  • Park, Minsu;Park, Jungheum;Lee, Sangjin
    • KIPS Transactions on Computer and Communication Systems
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    • v.2 no.2
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    • pp.93-102
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    • 2013
  • These days digital data have become essential for digital investigation because most of the crime was occurred by using the digital devices. However, digital data is very easier to falsify or delete. If digital data was deleted, it is necessary to recover the deleted data for obtain digital evidence. Even though file carving is the most important thing to gather. digital evidence in digital forensic investigation, most of popular carving tools don't contemplate methods of selection or restoration for digital forensic investigation. The goal of this research is suggested files which can obtain useful information for digital forensic investigation and proposed new record file carving technique to be able to recover data effectively than before it.

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

  • 홍성완;배규진;김창용;서용석;김광염
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.03a
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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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