• Structural Monitoring and Maintenance
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• 제7권4호
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• pp.367-392
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• 2020

The specific characteristics of near-field earthquake records can lead to different dynamic responses of bridges compared to far-field records. However, the effect of near-field strong ground motion has often been neglected in the seismic performance assessment of the bridges. Furthermore, damage to horizontally curved multi-frame RC box-girder bridges in the past earthquakes has intensified the potential of seismic vulnerability of these structures due to their distinctive dynamic behavior. Based on the nonlinear time history analyses in OpenSEES, this article, assesses the effects of near-field versus far-field earthquakes on the seismic performance of horizontally curved multi-frame RC box-girder bridges by accounting the vertical component of the earthquake records. Analytical seismic fragility curves have been derived thru considering uncertainties in the earthquake records, material and geometric properties of bridges. The findings indicate that near-field effects reasonably increase the seismic vulnerability in this bridge sub-class. The results pave the way for future regional risk assessments regarding the importance of either including or excluding near-field effects on the seismic performance of horizontally curved bridges.

• Earthquakes and Structures
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• 제22권3호
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• pp.263-275
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• 2022

Structural collapses can occur as a result of a dynamic amplification of either, the building's seismic response or the ground shaking by local site effects; one of the reasons is a resonance effect due to the proximity of the structural elastic fundamental period TE and the soil fundamental period TS. We evaluate the vulnerability to resonance effects in Guadalajara, México, in a three-step schema: 1) we define structural systems in the building environment of western Guadalajara, in terms of their construction materials and structural components; 2) we estimate TE with different equations, to obtain a representative value in elastic conditions for each structural system; and, 3) we evaluate the resonance vulnerability by the analysis of the ratio between TE and TS. We observe that the larger the soil fundamental period, the higher the resonance vulnerability for buildings with height between 17 and 39 m. For the sites with a low TS, the most vulnerable buildings will be those with a height between 2 and 9 m. These results can be a helpful tool for disaster prevention, by avoiding the construction of buildings with certain heights and structural characteristics that would result in a dangerous proximity between TE and TS.

• 한국대기환경학회지
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• 제28권1호
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• pp.22-38
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• 2012

Adaptation of climate change is necessary to avoid unexpected impacts of climate change caused by human activities. Vulnerability refers to the degree to which system cannot cope with impacts of climate change, encompassing physical, social and economic aspects. Therefore the quantification of climate change impacts and its vulnerability is needed to identify vulnerable regions and to setup the proper strategies for adaptation. In this study, climate change vulnerability is defined as a function of climate exposure, sensitivity, and adaptive capacity. Also, we identified regions vulnerable to ozone due to climate change in Korea using developed proxy variables of vulnerability of regional level. 18 proxy variables are selected through delphi survey to assess vulnerability over human health sector for ozone concentration change due to climate change. Also, we estimate the weighting score of proxy variables from delphi survey. The results showed that the local regions with higher vulnerability index in the sector of human health are Seoul and Daegu, whereas regions with lower one are Jeollanam-do, Gyeonggi-do, Gwangju, Busan, Daejeon, and Gangwon-do. The regions of high level vulnerability are mainly caused by their high ozone exposure. We also assessed future vulnerability according to the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES) A2, A1FI, A1T, A1B, B2, and B1 scenarios in 2020s, 2050s and 2100s. The results showed that vulnerability increased in all scenarios due to increased ozone concentrations. Especially vulnerability index is increased by approximately 2 times in A1FI scenarios in the 2020s. This study could support regionally adjusted adaptation polices and the quantitative background of policy priority as providing the information on the regional vulnerability of ozone due to climate change in Korea.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 춘계학술대회
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• pp.635-637
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• 2021

사이버 보안성 평가란 위협 및 취약성 분석을 통해 시스템의 위험 수준을 평가하여 적절한 보안조치를 취하기 위한 과정이다. 최근 증가하고 있는 사이버 공격과 지속적으로 개발되는 지능형 보안 위협에 대비하기 위해 정확한 보안 평가 모델이 필요하다. 따라서 보안 장비와 구간, 취약점마다 가중치를 할당하여 점수화하는 매트릭 기반 보안 평가 모델 분석을 통해 위험도 평가 모델을 제시한다. 사이버 보안성 평가 시 필요한 요소들을 간략화하고 기업 환경에 맞춰 평가가 가능하다. 보안 장비별 평가를 통하여 기업 환경에 더 적합한 평가를 시행하여 추후 사이버 보안 평가 연구에 도움이 될 것으로 기대된다.

• 수산해양교육연구
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• 제28권4호
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• pp.913-924
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• 2016

Re-consultation on Marine Environment Impact Assessment (MEIA) says that business operators are then licensed back from the disposition authorities undergoing a consultation process to change business plans. Marine Environment Management Act has provisions(Article 94) with respect to a case where the scale of business, the period of business, reflects the basic plan, including a plan to change a variety of reasons. But increasingly diverse types of businesses and projects which are the subject of MEIA, As it appears that the vulnerability issues and the problem of the re-consultation. In this study conducted an analysis of the literature review and comment on the re-consultation report four years. In addition, it presents a check to the problem through concrete examples related to the re-consultation and proposes improvement measures.

• 한국군사과학기술학회지
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• 제6권2호
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• pp.55-64
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• 2003

Underwater acoustic noise measurement is an essential element for vulnerability assessment of modern naval platforms. But during the last few decades environmental conditions have drastically changed due to the gradually increasing sea ambient noise level and decreasing submarine radiated noise level. A real-time underwater acoustic measurement system with vertical line array is designed for the quiet submarine radiated noise assessment in challenging environment. This system has a constant directivity index in measurement frequency range and accurate tracking capability for the transmission loss compensation and navigation aids inside the submarine. This system has been validated at sea and used several times for the submarine noise measurement.

• 해양환경안전학회지
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• 제21권3호
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• pp.266-273
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• 2015

Keeping in mind that there are only limited social, economic and administrative resources for reducing marine casualties, the result of statistical survey showed the loopholes of safe maritime transport system, and rendered that most casualties occurred in coastal waters by human errors. When the IMO Marine Casualty Investigation Code was utilized to reveal any structural vulnerability of the international measures, IMO was required to expand its roles to enhance the interface between Liveware and Environment of SHEL model. So, several risk assessment models were studied and found that Maritime Safety Audit System of the Republic of Korea could be a good example of enhancing safe interface between navigators (Liveware) and the navigational circumstances (Environment). It could be dealt with at IMO level as a tool for applying at human error enforcing waters. International cooperative research for upgrading risk assessment modes should also be future terms of reference.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2012년도 춘계학술대회
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• pp.456-460
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• 2012

개인정보보호법이 2012년 3월 30일 시행을 하였다. 일반적으로 개인정보를 관리하는 DB서버는 보안을 강화하기 위한 보안시스템을 갖추고 있으나, PC에서는 개인정보보호를 위한 취약점 분석과 보안성 자가진단에 대한 연구가 필요하다. 본 논문에서는 PC에서 개인정보보호 관련 정보를 검색하고, 암호화하여 보안성을 강화하고 삭제대상 파일은 복구 불가능하게 삭제한다. PC에서 검색된 취약성 분석은 사용자계정점검, 공유폴더점검, 서비스 방화벽 점검, 화면보호기, 자동패치업데이트를 점검한다. 점검 후에 취약점에 관한 정량화 분석과 표현을 통해, 보안성 강화를 위한 점검리스트을 작성해서 보여주고, PC보안 관리를 반자동화하여 서버에서 관리하여 작동시킨다. 본 논문을 통해 PC개인정보보호와 PC보안강화로 국민의 경제적 피해와 고충을 줄이는데 기여할 것이다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.64-65
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• 2006

This paper presents a user-friendly application for stochastic assessment of voltage sag and effective visualization for analysis data. This developed tool provides basic functions for voltage sag assessment such as load flow analysis, short circuit analysis and vulnerability analysis. Particularly it has the ability to edit one-line diagram of power system and to visualize analysis results effectively using computer graphic and animation. In order to give the real sense, analysis results are displayed with geographical information in an intuitive and rapid manner.

• 한국멀티미디어학회논문지
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• 제17권12호
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• pp.1494-1502
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• 2014

Since smartphones are utilized in the ranges from personal usages to governmental data exchanges, known but not patched vulnerabilities in smartphone operating systems are considered as major threats to the public. To minimize potential security breaches on smartphones, it is necessary to estimate possible security threats. So far, there have been numerous studies conducted to evaluate the security risks caused by mobile devices qualitatively, but there are few quantitative manners. For a large scale risk evaluation, a qualitative assessment is a never ending task. In this paper, we try to calculate relative risk levels triggered by software vulnerabilities from unsecured smartphone operating systems (Android and iOS) among 51 Asian countries. The proposed method combines widely accepted risk representation in both theory and industrial fields. When policy makers need to make a strategic decision on mobile security related agendas, they might find the presented approach useful.