• Journal of the Earthquake Engineering Society of Korea
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• v.15 no.4
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• pp.1-12
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• 2011

Seismic fragility analysis has been developed to evaluate the seismic performance of existing nuclear power plants, but now its applicability has been extended to buildings and bridges. In general, the seismic fragility curves are evaluated from the nonlinear time-history analysis (THA) using many earthquake ground motions. Seismic fragility analysis using the nonlinear THA requires a time consuming process of structural modeling and analysis. To overcome this shortcoming of the nonlinear THA, simplified methods such as the displacement coefficient method (DCM) and the capacity spectrum method (CSM) are used for the seismic fragility analysis. In order to evaluate the accuracy of the seismic fragility curve calculated by the DCM and the CSM, the seismic fragility curves of a reinforced concrete shear wall structure calculated by the DCM and CSM are compared with those calculated by the nonlinear THA. In order to construct a numerical fragility curve, 190 artificially generated ground motions corresponding to the design spectrum and the methodology proposed by Shinozuka et al. are used.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10a
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• pp.730-732
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• 2003

최근의 웜이나 바이러스로 인한 침해 사고는 다수의 불특정 시스템을 대상으로 하고 있으며 짧은 시간동안 다수의 시스템을 감염시킨다. 현재의 침해 사고의 처리는 시스템이 감염된 후 이를 처리하는 방식이나 이러한 방식으로는 짧은 시간 안에 급속도로 확산되는 침해사고를 막기가 힘들다. 본 논문에서는 칭해 사고의 효과적인 처리를 위한 새로운 프레임 워크를 제안하고자 한다. 평소에 관리하고자 하는 서버들의 정보를 수집하고 관리함으로써 새로운 취약점이 발견되었을 때 또는 침해 사고가 발생하였을 때 취약할 가능성이 있는 서버들을 신속히 파악하여, 취약점을 점검하는 도구를 생성하는데 필요한 공통 프레임 워크를 개발하여 보다 빠르게 취약점을 점검하는 도구를 생성, 이론 이용해 취약할 가능성이 있는 서버들을 점검한다. 점검결과 감염된 시스템은 치료하고 취약하나 감염이 되지 않은 시스템은 취약점을 제거한다. 제안된 프레임 워크는 명소에 서버들의 정보를 수집함으로써 침해사고가 발생하였을 감염 가능성이 있는 서버들을 빠르게 확인 할 수 있다. 또한 취약점 점검 도구 생성 프로그램을 사용함으로써 점검 코드의 삽입만으로 쉽게 취약점 점검 도구를 생성, 확산되기 전에 타 시스템에서 동종의 침입을 예방할 수 있다.

• The Journal of Society for e-Business Studies
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• v.16 no.2
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• pp.129-142
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• 2011

Traditionally research in Service Oriented Architecture(SOA) security has focused primarily on exploiting standards and solutions separately. There exists no unified methodology for SOA security to manage risks at the enterprise level. It needs to analyze preliminarily security threats and to manage enterprise risks by identifying vulnerabilities of SOA. In this paper, we propose a metric-based vulnerability assessment method using dynamic properties of services in SOA. The method is to assess vulnerability at the architecture level as well as the service level by measuring run-time dependency between services. The run-time dependency between services is an important characteristic to understand which services are affected by a vulnerable service. All services which directly or indirectly depend on the vulnerable service are exposed to the risk. Thus run-time dependency is a good indicator of vulnerability of SOA.

• Journal of Labour Economics
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• v.34 no.3
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• pp.29-58
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• 2011

Using careful background research and methodology, we proposed a revised sectoral index of vulnerability that is directly applied to two central labor examples: working hours and minimum wages. The valued calculated by each specific index represent the degree of weakness in corresponding conditions at the level of workplace units. Our proposed vulnerability index promises to be applicable to all business units under labor spot inspection. Also, it can be easily updated as the business environment evolves. The index is useful in selecting certain groups of business units and in evaluating the effectiveness of each regional government office.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.4
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• pp.26-37
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• 2020

This study intends to present a fragility analysis method suitable for concrete cable-stayed bridges by performing an analysis reflecting design criteria and material characteristics from the results of inelastic time-history analysis. In order to obtain the fragility curve of the cable-stayed bridge, the limit state of the main component of the cable-stayed bridge is determined, and the damage state is classified by comparing it with the response value based on inelastic time history analysis. The seismic fragility curve of the cable-stayed bridge was made by obtaining the probability of damage to PGA that the dynamic response of the vulnerable parts to input ground motion would exceed the limit state of each structural member. According to the pylon's fragility curve, the probability of moderate damage at 0.5g is 32% for the longitudinal direction, while 7% for the transversal direction, indicating that the probability of damage in the longitudinal direction is higher in the same PGA than in the transversal direction. The seismic fragility curve of the connections showed a very high probability of damage, meaning that damage to the connections caused by earthquakes is very sensitive compared to damage to the pylon and cables. The cable's seismic fragility curve also showed that the probability of complete damage state after moderate damage state gradually decreased, resulting in less than 30% probability of complete damage at 2.0g.

• Journal of the Earthquake Engineering Society of Korea
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• v.14 no.5
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• pp.65-76
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• 2010

In this paper, earthquake fragility analysis has been comparatively performed with regard to a buried gas pipeline of API X65 which has been widely used in Korea. For this purpose, a nonlinear time-history analyses has been carried out for 15 different analytical models of a buried gas pipeline in terms of the selected 12 sets of earthquake ground motions with 0.1g of scaling interval. Following that, earthquake fragility analyses have been conducted using the maximum axial strain of the pipeline obtained from the nonlinear time-history analyses. Parameters under consideration for subsequent earthquake fragility analyses are soil conditions, end-restraint conditions, burial depth and the type of pipeline. Comparative analyses reveal that whereas the first three parameters influence the fragility curves, particularly soil conditions amongst the three parameters, the last parameter has a little effect on the curves. In all, the present study can be considered as a benchmark fragility analysis of a buried gas pipeline in the absence of an earthquake fragility analysis of the pipeline and thus is expected to be a useful source regarding earthquake fragility analyses of a buried gas pipelines.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.4D
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• pp.547-553
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• 2011

This study has redefined the concepts of mobility indexes and potential demand, standards to evaluate areas with the worst public transportation system and applied the relevant indexes to select the areas with the worst public transportation mobility and present a method to set direct public transportation lines between these regions. The mobility indexes and indexes to evaluate potential demand were applied to select the regions with the worst public transportation systems in four metropolitan cities and case studies were carried out on direct lines provided between these regions. The analysis results showed that in public transportation mobility blind spots, public transportation takes much longer than driving an automobile or public transportation services are not provided. In addition, the analysis showed that a direct lines system to solve such worst off regions should be built to have public transportation take as much time as driving an automobile by establishing lines for automobiles only, minimize time lost from hopping up and down a bus and maximize connections.

• The Journal of the Convergence on Culture Technology
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• v.8 no.5
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• pp.597-602
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• 2022

In construction sites, many accidents occur without supervisors during night work, early work, and lunchtime work outside of regular working hours. The purpose of this study is to measure the safety level of workers and to provide basic data for preventing accidents during vulnerable times by analyzing the opinions of expert groups on working conditions. Working conditions were divided into four areas: basic conditions, physical environment, social environment, and physiological factors. After examining the correlation between the priority considerations determined by Analytic Hierarchy Process (AHP) and the safety level of workers investigated in advance, management plans for each factor was derived.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.04a
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• pp.424-425
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• 2014

2014년 가트너에서 조사된 통계 자료에 의하면 스마트폰 사용자 4명중 3명은 안드로이드인 것으로 나타났다. 즉, 안드로이드에서 취약점이 발생할 경우 다른 스마트폰 OS에서 취약점이 발생할 때보다 3배 이상의 피해가 예상된다고 할 수 있다. 따라서 안드로이드 환경에서 앱에 대한 취약점을 찾고 조치를 취해야하는 작업이 지속되어야 한다. 그러나 취약점을 찾고 조치를 취하기 위해 분석가는 많은 시간을 소모하는데 비해 앱의 증가 속도는 매우 빨라 취약점 점검을 위한 자동화 도구는 필수적일 수밖에 없다. 이에 본 연구는 안드로이드 환경에서 작동하는 앱을 대상으로 취약점 점검을 수행하는 도구를 개발하고 연구하였다.

• Journal of the Earthquake Engineering Society of Korea
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• v.8 no.1
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• pp.67-76
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• 2004

This study presents the evaluation of CSM(Capacity Spectrum Method, ATC-40) in developing fragility curves for a sample concrete bridge. The CSM is originally developed as one of the simplified procedures for building structures, while this study adopts the CSM to develop fragility curves of bridge structures. Four(4) different approaches are demonstrated and the fragility curves developed are compared those by the nonlinear time history analysis. Fragility curves in this study are represented by lognormal distribution functions with two parameters and developed as a function of PGA. The sixty(60) ground acceleration time histories for the Los Angeles area developed for the Federal Emergency Management Agency (FEMA) SAC(SEAOC-ATC-CUREe) steel project are used for the bridge analysis. The comparison of fragility curves by the CSM with those by the time history analysis indicates that the agreement is excellent for one of the methods investigated in this study. In this respect. it is recommended that the demand spectrum might be improved according to the guidelines suggested in this study. However, this observation might not always apply, depending on the details of specific bridge characteristic