• 해양환경안전학회지
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• 제24권6호
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• pp.825-833
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• 2018

본 연구에서는 LNG 공급계통시스템의 재기화 공정에서 배관 손상으로 인한 누출사고 발생시 LNG 성분 및 누출공의 크기에 따른 연소특성에 대한 피해범위를 산출하고, 피해영향을 해석하였다. LNG 성분에 따른 연소특성을 확인하기 위하여 7곳의 LNG 산지별 위험도를 확인한 결과 산지별 큰 차이를 보이지 않았으나, LNG 구성성분 중 메탄의 함유량이 많을수록 플래시화재 발생범위 및 증기운 폭발에 의한 과압이 발생하는 위험범위 그리고 제트화재 발생에 의한 열 복사량 피해영향이 다른 산지에 비해 비교적 낮음을 알 수 있었다. 또한 배관 누출공의 크기에 따라 누설, 파공, 파괴 3단계에 나누어 위험 범위 및 폭발에 미치는 영향에 대한 연구를 수행하였으며, 플래시화재로 인한 피해영향범위를 계산하고, 이에 따라 LNG 누출시 화재가능 위험범위를 확인했으며, 과압의 영향 및 복사열로 부터의 피해범위를 예측할 수 있었다. 이를 통해 LNG 조성 및 배관 누출공의 크기가 화재 및 폭발에 미치는 영향을 예측할 수 있었다.

• Journal of Advanced Marine Engineering and Technology
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• 제35권7호
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• pp.946-956
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• 2011

The main objectives of this study are to analyze the leaked gas dispersion and quantify the potential overpressures due to vapor cloud explosions in order to identify the most significant contributors to risk by using Computational Fluid Dynamics (CFX & FLACS) for gas fuelled ships. A series of CFD simulations and analyses have been performed for the various gas release scenarios in a closed module, covering different release rates and ventilating methods. This study is specially focused on the LNG FGS (Fuel Gas Supply) system recently developed for the propulsion of VLCC crude oil carriers by shipyards. Most of work presented is discussed on the gas dispersion from leaks in the FGS room, and shows some blast prediction validation examples.

• Journal of Platform Technology
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• 제6권3호
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• pp.3-9
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• 2018

This paper describes the design and trial development of a system that supports continuous hazard mapping by local residents in their daily life. We performed an interview survey to design our system in a model traditional town in Saga Prefecture, Japan. The results show that despite continued efforts, many practical problems remain and residents feel unsafe. Considering these results, we designed and developed a unique information and communication technology-based support system that contributes to community-based disaster prevention and reduction. The continuous resident participation and posting design are the core concept for our community-based approach. Our system continues to support making a hazard map by integrating the community-based hazard information. Local residents register information (disaster types, risk level, photographs, comments, positional information) about locations that could be dangerous in a disaster. In addition, our system enables information sharing through a Web server. We expect that this information sharing will allow local hazard information for each district to be used.

• 한국안전학회지
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• 제14권2호
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• pp.109-115
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• 1999

The release of gas from the LPG storage tank by the rupture or leakage can occure explosion and this causes serious damage to people and structures. In this study, the explosion effect and damaging distance were measured for the LPG cloud explosion to perform the quantitative risk assessment for the PSM, and the effective parameters on the explosion were found. The gas dispersion and mass contaminant in the explosion limits were calculated by using DEGADIS, and it was converted to TNT equivalency and damaging distance. As a result, the wind speed was the most effective parameter on the diffusion rate and TNT equivalency, and the damaging distance were increased with decrease of wind speed and surface roughness.

• 한국멀티미디어학회논문지
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• 제19권5호
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• pp.918-923
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• 2016

IoT should be considered security risk environments such as various platforms and services including smart devices that can be mounted on household electric appliances, healthcare, car, and heterogeneous networks that are connected to the Internet, cloud services and mobile Apps.. In this paper, we provide analysis of new security threats, caused by open-platform of IoT and sensors via the Internet. Also, we present the key recovery mechanism that is applied to IoT. It results to have compatibility with given research, reduces network overhead, and performs key recovery without depending on key escrow agencies or authorized party.

• 한국방재학회 논문집
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• 제9권2호
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• pp.45-51
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• 2009

지구기후모델을 이용하여 예측된 (1) 물성치와 (2) 현재 및 미래의 표면 에너지 입력상수의 가변성을 고려한 동결 및 융해깊이를 예측하기 위하여 확률론적 접근법이 도입되었다. 확률론적 접근법을 예시하기 위하여 극지방에서의 융해깊이 예측을 고려해보았다. 특히 확률론적 융해깊이 예측을 위하여 몬테카를로 시뮬레이션과 함께 Stefan 공식이 사용되었다. 시뮬레이션 결과는 물성치의 가변성을 보여주었다. 표면 에너지 입력상수와 온도 데이터는 융해깊이를 예측하는데 상당한 불확실성을 야기시킬 수 있다.

• 디지털산업정보학회논문지
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• 제9권1호
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• pp.1-7
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• 2013

The cloud computing is technology which gives flexible and solid infrastructure to IT environment. With this technology multiple computing environment can be consolidated in to a single server so that maximize system resource utilization. Better processing power can be achieved with less system resource. IT manager can cope with increasing unnecessary cost for additional server and management cost as well. This means a enterprise is able to provide services with better quality and create new services with surplus resource. The time required for recovery from system failure will be reduced from days to minutes. Enhanced availability and continuity of enterprise business minimize the codt and the risk produced by service discontinuity. In this paper, we propose framework architecture that is strong against denial-of-service attack.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2015년도 추계학술발표대회
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• pp.763-766
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• 2015

Smart Healthcare System as an Open Platform (Shesop) is an integrated healthcare system and have several features, one of them is Steppy Application. Steppy does count your step and display on Shesop website. In this system security issues are not properly addressed, while Personal Health Record (PHR) patient stored in the cloud platform could be at risk. In fact, the huge electronic information available online, people needs reliable and effective technique for privacy preserving. In order to improve the security of data which are displayed on the Shesop website, so that anyone who access could not tamper without permission. Recently Xu et al. showed a pseudonym scheme using smart card as a solution in e-health systems which uses discrete logarithm problem with cyclic group. In this paper, we adopt their scheme and use it application into smartphone using Near Field Communication (NFC) to construct security in Steppy apps.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2019년도 춘계학술발표대회
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• pp.216-218
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• 2019

클라우드 서비스 기반의 시스템은 기존의 물리적 인프라 기반의 서비스에 비해 전사관점의 투자 Risk 를 줄이고 보다 효율적인 시스템의 구축과 운영을 가능하게 한다. 그러나 이러한 장점을 제공하기 위한 클라우드 서비스의 서비스모델과 기술적 관점의 특징으로 인해 기존보다 더 많은 보안 취약점에 노출될 수 있다. 이러한 보안 취약점에 효과적인 대응을 하기 위해서는 이러한 클라우드 서비스의 특징을 이해하고 이를 기반으로 한 기술적/관리적 보안 대응책을 정의하고 실행하는 것이 필요하다. 이에 본 고에서는 클라우드 서비스의 특징을 살펴보고 이를 기반으로 하는 보안 취약점을 파악 이에 대한 대응 방안에 대해 제시하도록 한다.

• International Journal of Internet, Broadcasting and Communication
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• 제11권1호
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• pp.97-102
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• 2019

As the number of "Mobility Handicapped" increases, the incidence of "Mobility Handicapped" traffic accidents is also increasing. In order to reduce the incidence of traffic accidents in the "Mobility Handicapped", a service providing system for "Mobility Handicapped" is required. Since these services have different data formats, data heterogeneity occurs. Therefore, the system should resolve the data heterogeneity by mapping the format of the data. In this paper, we design DBaaS as a mobility handicapped system for data interoperability. This system provides a service to extend the flashing time of the traffic lights according to the condition of "Mobility Handicapped" on the occurrence of a fall or a crosswalk in a crosswalk where there is a risk of a traffic accident. These services can reduce the incidence of traffic accidents in "Mobility Handicapped".