• 제목/요약/키워드: Risk Assessment Techniques

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사건수 분석 기법을 이용한 필댐의 내부 침식 위험도에 대한 지반공학적 시스템 응답 확률 산정 (Estimating Geotechnical System Response Probability of Internal Erosion Risk in Fill Dam using Event Tree Analysis)

  • 노경륜;임정열;목영진;정영훈
    • 대한토목학회논문집
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    • 제34권6호
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    • pp.1815-1829
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    • 2014
  • 최근 빈번하게 발생하는 노후 필댐의 붕괴 사고로 인해 안전관리에 대한 사회적 관심이 높아지고 있다. 지금까지 국내에서는 설계 당시 보수적인 설계기준에 근거한 설계 홍수량을 기준으로 필댐의 안정성을 단순하게 평가하고 있다. 하지만 해외 주요 국가에서는 사건수 분석 기법과 같은 체계적인 위험도 평가 기법을 도입하여 이미 오랜 기간 동안 필댐을 관리 운영하고 있다. 본 연구에서는 노후화된 국내 필댐의 체계적인 위험도 분석을 위해 사건수 분석 기법을 이용한 미공병단 내부 침식 평가 기법을 적용하여 필댐의 내부 침식에 대한 지반공학적 시스템 반응 확률을 분석하였다. 본 연구 결과는 지반공학적 시스템 반응 확률이 결함의 존재 확률과 동수경사의 크기에 가장 큰 영향을 받으며 노후된 필댐의 위험도를 정량적으로 평가할 수 있음을 보여준다.

Managing the Vulnerability of Megacities in North America and Europe to Seismic Hazards

  • Waugh, William L.
    • 한국화재소방학회논문지
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    • 제15권2호
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    • pp.20-30
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    • 2001
  • The science and technology of seismic hazard mitigation are increasingly being shared among scientists and policy makers around the world. Administrative expertise is also being shared. While there is still tremendous unevenness in technical and administrative capacities and resources, a global community of emergency managers is developing and there is a globalization of expertise. Hazards are better understood, tools for risk assessment are improving, techniques for hazard mitigation are being perfected, and communities and states are implementing more comprehensive disaster preparedness, response, and recovery programs. Priorities are also emerging and hazard mitigation has emerged as the priority of choice in North America and Europe. An increasingly important component of hazard mitigation is resilience, in terms of increased capacities for disaster mitigation and recovery at the community and even individual levels. Each year, more is known about the locations and natures of seismic hazards, although there are still unknown and poorly understood fault lines and limited understanding of related disasters such as tsunamis and landslides. More is known about the impact of earthquakes on the built environment, although nature still provides surprises to confound man's best extorts to reduce risk. More is known about human nature and how people respond to uncertain risk and when confronted by certain catastrophe. However, despite the increased understanding of seismic phenomena and how to protect people and property, there is much that needs to be done to reduce the risk, particularly in major metropolitan areas.

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정보보호를 위한 다속성 위협지수 : 시뮬레이션과 AHP 접근방법 (Multi-Attribute Threat Index for Information Security : Simulation and AHP Approach)

  • 이강수;김기윤;나관식
    • 한국IT서비스학회지
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    • 제7권1호
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    • pp.117-130
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    • 2008
  • Multi-attribute risk assessments provide a useful framework for systematic quantitative risk assessment that the security manager can use to prioritize security requirements and threats. In the first step, the security managers identify the four significant outcome attributes(lost revenue, lost productivity, lost customer, and recovery cost). Next. the security manager estimates the frequency and severity(three points estimates for outcome attribute values) for each threat and rank the outcome attributes according to AHP(Analytic Hierarchy Process). Finally, we generate the threat index by using muiti-attribute function and make sensitivity analysis with simulation package(Crystal Ball). In this paper, we show how multi-attribute risk analysis techniques from the field of security risk management can be used by security managers to prioritize their organization's threats and their security requirements, eventually they can derive threat index. This threat index can help security managers to decide whether their security investment is consistent with the expected risks. In addition, sensitivity analysis allows the security manager to explore the estimates to understand how they affect the selection.

MS Windows에서 인젝션 공격 및 방어 기법 연구 (A Study on Injection Attacks and Defenses on Microsoft Windows)

  • 성호준;조창연;이호웅;조성제
    • 한국소프트웨어감정평가학회 논문지
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    • 제16권2호
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    • pp.9-23
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    • 2020
  • 기업이나 기관의 데스크톱 및 엔터프라이즈 서버용 운영체제로 마이크로소프트사의 Windows가 많이 활용되고 있고 사이버 공격의 주요 대상이 되고 있다. 마이크로소프트사는 다양한 보호 기술을 제공하고 주기적인 보안 패치를 통해 노력하고 있지만, 여전히 DLL 인젝션(injection)이나 프로세스 인젝션 등의 공격 위협이 존재하고 있다. 본 논문에서는 Windows 시스템에서 12가지 인젝션 공격 기법에 대해 분석하고, 4개의 응용 프로그램들을 대상으로 인젝션 공격 실험을 수행한다. 실험 결과를 통해 인젝션 공격의 위험성을 파악하고, 마이크로소프트에서에서 제공하는 인젝션 공격에 대한 완화 기술의 유효성을 검증한다. 실험 결과, 현재 응용 프로그램들이 여러 인젝션 공격에 취약함을 알 수 있었다. 최종적으로, 이러한 인젝션 공격에 대한 완화 기법을 제시하고 효용성을 분석하였다.

Deformation-based vulnerability functions for RC bridges

  • Elnashai, A.S.;Borzi, B.;Vlachos, S.
    • Structural Engineering and Mechanics
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    • 제17권2호
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    • pp.215-244
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    • 2004
  • There is an ever-increasing demand for assessment of earthquake effects on transportation structures, emphasised by the crippling consequences of recent earthquakes hitting developed countries reliant on road transportation. In this work, vulnerability functions for RC bridges are derived analytically using advanced material characterisation, high quality earthquake records and adaptive inelastic dynamic analysis techniques. Four limit states are employed, all based on deformational quantities, in line with recent development of deformation-based seismic assessment. The analytically-derived vulnerability functions are then compared to a data set comprising observational damage data from the Northridge (California 1994) and Hyogo-ken Nanbu (Kobe 1995) earthquakes. The good agreement gives some confidence in the derived formulation that is recommended for use in seismic risk assessment. Furthermore, by varying the dimensions of the prototype bridge used in the study, and the span lengths supported by piers, three more bridges are obtained with different overstrength ratios (ratio of design-to-available base shear). The process of derivation of vulnerability functions is repeated and the ensuing relationships compared. The results point towards the feasibility of deriving scaling factors that may be used to obtain the set of vulnerability functions for a bridge with the knowledge of a 'generic' function and the overstrength ratio. It is demonstrated that this simple procedure gives satisfactory results for the case considered and may be used in the future to facilitate the process of deriving analytical vulnerability functions for classes of bridges once a generic relationship is established.

Influence line- model correction approach for the assessment of engineering structures using novel monitoring techniques

  • Strauss, Alfred;Wendner, Roman;Frangopol, Dan M.;Bergmeister, Konrad
    • Smart Structures and Systems
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    • 제9권1호
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    • pp.1-20
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    • 2012
  • In bridge engineering, maintenance strategies and thus budgetary demands are highly influenced by construction type and quality of design. Nowadays bridge owners and planners tend to include life-cycle cost analyses in their decision processes regarding the overall design trying to optimize structural reliability and durability within financial constraints. Smart permanent and short term monitoring can reduce the associated risk of new design concepts by observing the performance of structural components during prescribed time periods. The objectives of this paper are the discussion and analysis of influence line or influence field approaches in terms of (a) an efficient incorporation of monitoring information in the structural performance assessment, (b) an efficient characterization of performance indicators for the assessment of structures, (c) the ability of optimizing the positions of sensors of a monitoring system, and (d) the ability of checking the robustness of the monitoring systems applied to a structure. The proposed influence line- model correction approach has been applied to an integrative monitoring system that has been installed for the performance assessment of an existing three-span jointless bridge.

코로나-19 상황에 대응하는 항공안전조직의 RAG(Resilience Assessment Grid) 적용 (Application of RAG(Resilience Assessment Grid) of the Aviation Safety Organization in Response to the COVID-19 Situation)

  • 김대호
    • 한국항공운항학회지
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    • 제29권1호
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    • pp.38-46
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    • 2021
  • The Organization's ability to respond to social disasters has begun to be treated as important through social shock situations that have never been experienced, such as COVID-19. Among them, the ability to respond to unexpected risks and resilience is emerging. Since social disasters such as infectious diseases are periodically repeated, compounded, and enlarged, they develop into a global crisis situation, so this crisis response capability is treated as national competitiveness. Therefore, this study aims to improve the organization's response capability in terms of risk response and resilience under rapid social disasters such as COVID-19. The aviation safety field was taken as an example. From the Safety-II perspective, safety management focuses on the ability to resilience in response to system vulnerabilities in various situations. In this study, I intend to apply RAG(Resilience Assessment Grid) of Respond, Monitor, Learn and Anticipate, the four major potential of resilience engineering. Based on Hollnagel's research, potential elements were classified into four, and items were organized through an expert panel using Delphi techniques. The final configured RAG items are 15 Respond, 15 Monitor, 15 Learn and 11 Anticipate. The RAG was evaluated by 42 experts in the field of aviation safety.

감전재해 예방을 위한 전기공사업의 특성에 관한 연구 (A Study on the Characteristic of Electrical Construction Work for Prevention of Electric Shock Accident)

  • 최상원
    • 한국안전학회지
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    • 제29권5호
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    • pp.29-34
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    • 2014
  • The live line working is inherently dangerous as the workers have to work under the risk of electrical shock and most of works are carried out at height. The live line working need the some specific techniques and higher level safety measures such as a risk assessment to carry out works safely, but the electrical construction companies performed live-line working are usually small-sized companies. They have less capacity to have own safety management system. This study intended to conduct an in-depth analysis on the cause of electric shock accidents to provide basic data for policy proposing taking into considering the past eleven years for a long-term plan. And the aim of this study is to propose the policy about the equipment performance standards and/or worker's safety standards to revise the standards for preventing electric shock accidents, moreover, co-relation of the electrical work order form and on safety workings, especially electrical construction company/work.

복합화력발전의 가스연료 공급계통에 대한 위험도 평가 기법 연구 (II) : 배관 시스템 응력 해석을 이용한 위험도 평가 (Risk Assessment Technique for Gas Fuel Supply System of Combined Cycle Power Plants (II) : Based on Piping System Stress Analysis)

  • 유종민;송정수;정태민;럭 완노;윤기봉
    • 에너지공학
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    • 제27권2호
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    • pp.14-25
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    • 2018
  • 복합화력발전 플랜트는 천연가스와 같은 연료로 가스 터빈을 작동시킨 후 잔류 열로 증기를 생산하는 사이클을 가지고 있다. 연료가스는 압축기 및 열교환기를 통해 4~5 MPa, $200^{\circ}C$ 수준의 상태로 가스터빈에 공급된다. 본 연구에서는 가스 연료공급 배관계통의 안전 운영 및 건전성 확보를 위해 배관 시스템 응력을 고려한 위험도 평가 기법 연구를 수행하였다. 위험도 평가 기법으로 잘 알려진 API 580/581 RBI 코드에서는 위험도에 배관 응력의 영향을 반영이 제한적이다. 따라서 배관 해석을 이용하여 배관의 시스템적 응력을 위험도의 파손확률로써 인자화하는 접근법을 제시하였다. 해석은 가상 발전 플랜트의 가스연료 공급 배관의 설계 데이터에 근거하여 배관 시스템 응력 해석을 수행하였다. API 코드에 의해서 평가된 파손확률 등급과 배관해석을 이용한 응력비 평가 결과를 비교하였다.

Agent Based Information Security Framework for Hybrid Cloud Computing

  • Tariq, Muhammad Imran
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제13권1호
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    • pp.406-434
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    • 2019
  • In general, an information security approach estimates the risk, where the risk is to occur due to an unusual event, and the associated consequences for cloud organization. Information Security and Risk Management (ISRA) practices vary among cloud organizations and disciplines. There are several approaches to compare existing risk management methods for cloud organizations but their scope is limited considering stereo type criteria, rather than developing an agent based task that considers all aspects of the associated risk. It is the lack of considering all existing renowned risk management frameworks, their proper comparison, and agent techniques that motivates this research. This paper proposes Agent Based Information Security Framework for Hybrid Cloud Computing as an all-inclusive method including cloud related methods to review and compare existing different renowned methods for cloud computing risk issues and by adding new tasks from surveyed methods. The concepts of software agent and intelligent agent have been introduced that fetch/collect accurate information used in framework and to develop a decision system that facilitates the organization to take decision against threat agent on the basis of information provided by the security agents. The scope of this research primarily considers risk assessment methods that focus on assets, potential threats, vulnerabilities and their associated measures to calculate consequences. After in-depth comparison of renowned ISRA methods with ABISF, we have found that ISO/IEC 27005:2011 is the most appropriate approach among existing ISRA methods. The proposed framework was implemented using fuzzy inference system based upon fuzzy set theory, and MATLAB(R) fuzzy logic rules were used to test the framework. The fuzzy results confirm that proposed framework could be used for information security in cloud computing environment.