• Wind and Structures
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• 제23권5호
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• pp.449-464
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• 2016

Catastrophe models appraise the natural risk of the built-infrastructure simulating the interaction of its exposure and vulnerability with a hazard. Because of unique configurations and reduced number, mid/high-rise buildings present singular challenges to the assessment of their damage vulnerability. This paper presents a novel approach to estimate the vulnerability of mid/high-rise buildings (MHB) which is used in the Florida Public Hurricane Loss Model, a catastrophe model developed for the state of Florida. The MHB vulnerability approach considers the wind pressure hazard exerted over the building's height as well as accompanying rain. The approach assesses separately the damages caused by wind, debris impact, and water intrusion on building models discretized into typical apartment units. Hurricane-induced water intrusion is predicted combining the estimates of impinging rain with breach and pre-existing building defect size estimates. Damage is aggregated apartment-by-apartment and story-by-story, and accounts for vertical water propagation. The approach enables the vulnerability modeling of regular and complex building geometries in the Florida exposure and elsewhere.

• 한국시뮬레이션학회논문지
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• 제13권3호
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• pp.11-20
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• 2004

The major objective of this paper is to perform modeling of cyber attack and defense using vulnerability metrics. To do this, we have attempted command level modeling for realizing an approach of functional level proposed by Nong Ye, and we have defined vulnerability metrics that are able to apply to DEVS(Discrete Event System Specification) and performed modeling of cyber attack and defense using this. Our approach is to show the difference from others in that (i) it is able to analyze behaviors of systems being emerged by interaction between functional elements of network components, (ii) it is able to analyze vulnerability in quantitative manner, and (iii) it is able to establish defense suitably by using the analyzed vulnerability. We examine an example of vulnerability analysis on the cyber attack and defense through case study.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2003년도 춘계학술대회논문집
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• pp.191-198
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• 2003

The major objective of this paper is to perform modeling of cyber attack and defense using vulnerability metrics. To do this, we have attempted command level modeling for realizing an approach of functional level proposed by Nong Ye, and we have defined vulnerability metrics that are able to apply to DEVS(Discrete Event System Specification) and performed modeling of cyber attack and defense using this. Our approach is to show the difference from others in that (ⅰ) it is able to analyze behaviors of system emerged by interaction with functional elements of components composing network and each other, (ⅱ) it is able to analyze vulnerability in quantitative manner, and (ⅲ) it is able to establish defense suitably by using the analyzed vulnerability. We examine an example of vulnerability analysis on the cyber attack and defense through case study.

• Geomechanics and Engineering
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• 제18권6호
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• pp.661-668
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• 2019

Seismic vulnerability assessment is a useful tool for rational safety analysis and planning of large and complex structural systems; it can deal with the effects of uncertainties on the performance of significant structural systems. In this study, an efficient dynamic reliability approach, probability density evolution methodology (PDEM), is proposed for seismic vulnerability analysis of earth dams. The PDEM provides the failure probability of different limit states for various levels of ground motion intensity as well as the mean value, standard deviation and probability density function of the performance metric of the earth dam. Combining the seismic reliability with three different performance levels related to the displacement of the earth dam, the seismic fragility curves are constructed without them being limited to a specific functional form. Furthermore, considering the seismic fragility analysis is a significant procedure in the seismic probabilistic risk assessment of structures, the seismic vulnerability results obtained by the dynamic reliability approach are combined with the results of probabilistic seismic hazard and seismic loss analysis to present and address the PDEM-based seismic probabilistic risk assessment framework by a simulated case study of an earth dam.

• The Journal of Asian Finance, Economics and Business
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• 제4권4호
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• pp.5-15
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• 2017

The Northern States of Malaysia comprises of four states (Penang, Kedah, Perlis and Perak) still record high poverty incidence eventhough Malaysia has experienced a remarkable reduction of poverty over the past century. Economic activities in Perlis and Kedah that are predominantly agriculture in the rural area contribute to this disparity. To add, rural households are also subject to risks and uncertainties that make them more vulnerable to poverty. This study examines the impact of risks and assets on households' vulnerability to poverty. A survey of 400 respondents was conducted in December 2015 in the northern region of Malaysia. From these 400 questionnaires, only 298 were considered valid and used in the analysis. Using a logistic probability function, the results indicated that risks are not a significant threat to households. Gender and strata are crucial elements that significantly determine households' vulnerability. While human capital and financial capital significantly reduce households' vulnerability to poverty, physical and natural capitals were not statistically significant. The study suggests that the government and practitioners design strategies and policies with an assets-based approach. The asset-based approach is more appropriate for linking the causes of poverty to vulnerability.

• Wind and Structures
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• 제38권5호
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• pp.355-366
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• 2024

Severe natural multi-hazard events can cause damage to infrastructure and economic losses of billions of dollars. The challenges of modeling these losses include dependency between hazards, cause and sequence of loss, and lack of available data. This paper presents and explores multi-hazard loss modeling in the context of the combined wind and rain vulnerability of mid/high-rise buildings during hurricane events. A component-based probabilistic vulnerability model provides the framework to test and contrast two different approaches to treat the multi-hazards: In one, the wind and rain hazard models are both decoupled from the vulnerability model. In the other, only the wind hazard is decoupled, while the rain hazard model is embedded into the vulnerability model. The paper presents the mathematical and conceptual development of each approach, example outputs from each for the same scenario, and a discussion of weaknesses and strengths of each approach.

• 정보보호학회논문지
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• 제13권5호
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• pp.69-79
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• 2003

업무연속성 관점에서 IDEF 접근방법에 의해서 주요 업무 프로세스를 파악하고, 관련 정보자산을 Skandia 모형으로 식별 한 후에, OCTAVE 접근방법에 의해서 위협을 단계적으로 분석하기 위해서, Nessus Version 1.4.2를 이용하여 도서관 정보시스템 중에서 가장 중요한 자산인 서버에 대해서 취약성을 평가했다. 기존 OCTAVE 접근방법에 IDEF 접근방법과 Skandia 모형을 동시에 이용하는 개선된 OCTAVE 접근방법을 이용한 취약성 평가 사례를 제시했다.

• Korean Circulation Journal
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• 제53권9호
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• pp.581-593
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• 2023

In the catheterization laboratory, the measurement of physiological indexes can help identify functionally significant lesions and has become one of the standard methods to guide treatment decision-making. Plaque vulnerability refers to a coronary plaque susceptible to rupture, enabling risk prediction before coronary events, and it can be detected by defining a certain type of plaque morphology on coronary imaging modalities. Although coronary physiology and plaque vulnerability have been considered different attributes of coronary artery disease, the underlying pathophysiological basis and clinical data indicate a strong correlation between coronary hemodynamic properties and vulnerable plaque. In prediction of coronary events, emerging data have suggested independent and additional implications of a physiology-based approach to a plaque-based approach. This review covers the fundamental interplay between coronary physiology and plaque morphology during disease progression with clinical data supporting this relationship and examines the clinical relevance of physiological indexes in prediction of clinical outcomes and therapeutic decision-making along with plaque vulnerability.

• 한국수자원학회논문집
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• 제45권9호
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• pp.901-913
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• 2012

본 연구는 불확실성을 고려하여 홍수 취약성 평가를 정량화하기 위한 새로운 방법을 제시하였다. 현실 세계로부터 얻는 많은 정보들은 불확실성을 가지고 있으므로 본 연구는 우리나라의 공간적 홍수 취약성을 산정하기 위해 Fuzzy TOPSIS기법을 사용하였다. 또한 Fuzzy TOPSIS의 결과를 TOPSIS 및 가중합계법을 적용한 결과와 비교하였다. 그 결과 일부지역의 취약성 순위가 큰 폭으로 역전되는 현상을 보였다. Spearman 순위 상관분석을 실시한 결과 TOPSIS와 가중합계법의 순위는 높은 일치성을 보였으나 Fuzzy TOPSIS의 순위와는 상당히 일치하지 않은 결과를 나타냈다. 즉, Fuzzy 개념을 반영하여 지역별 취약성을 산정할 경우 우선순위의 변동이 크게 발생할 수 있으므로 본 연구에서 제시한 모형도 하나의 취약성 평가의 방법이 될 수 있다.

• Earthquakes and Structures
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• 제12권5호
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• pp.489-499
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• 2017

The effects of past earthquakes have demonstrated the seismic vulnerability of confined masonry structures (CMSs) to earthquakes. The results of experimental analysis indicate that damage to these structures depends on lateral displacement applied to the walls. Seismic evaluation lacks an analytical approach because of the complexity of the behavior of this type of structure; an empirical approach is often used for this purpose. Seismic assessment and risk analysis of CMSs, especially in area have a large number of such buildings is difficult and could be riddled with error. The present study used analytical and numerical models to develop a simplified nonlinear displacement-based approach for seismic assessment of a CMS. The methodology is based on the concept of ESDOF and displacement demand and is compared with displacement capacity at the characteristic period of vibration according to performance level. Displacement demand was identified using the nonlinear displacement spectrum for a specified limit state. This approach is based on a macro model and nonlinear incremental dynamic analysis of a 3D prototype structure taking into account uncertainty of the mechanical properties and results in a simple, precise method for seismic assessment of a CMS. To validate the approach, a case study was considered in the form of an analytical fragility curve which was then compared with the precise method.