• Proceedings of the Korean Information Science Society Conference
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• 2006.10d
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• pp.370-374
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• 2006

Ad-hoc 환경의 응용은 재난구조나 회의실 또는 강의실에서의 정보 교환과 같은 그룹 통에서 이용된다. Ad-hoc 환경은 무선 채널을 이용하므로 상대적인 낮은 대역폭과 높은 오류 발생률을 가지게 된다. 따라서 Ad-hoc 네트워크에서는 신뢰적인 전송이 요구된다. 이동 노드는 상대적으로 낮은 성능과 에너지의 제한으로 인해 유선 환경과 같은 신뢰적인 전송 기법을 Ad-hoc 환경에 적용하기에는 문제가 발생한다. Ad-hoc 환경의 무선 채널이 가지는 보안적인 취약성과 높은 에러율을 극복하는 신뢰적인 그룹 키 전송을 위한 재전송 기법을 제안한다. 신뢰적인 트리 형성하기 위해 n차 트리 구조를 이용한다. 손실 감지를 위한 ACK 메시지를 이용하고 손실 복구를 위한 재전송 기법에 대해 연구를 한다. 제안한 신뢰적인 그룹 키 전송을 위한 재전송 기법은 트리의 깊이의 차수가 루트 관리 노드, 서브 관리 노드와 로컬 멤버 노드로 구성되기 때문에 손실 감지와 손실 복구에 대한 연산의 오버헤드가 적다. 루트 관리 노드는 멤버 노드로부터 받은 개인키 정보를 이용하여 그룹 키를 생성하고 그룹 키 부분 정보를 서브 관리 노드에게 전송하고 서브 관리 노드에 대한 신뢰성을 책임진다. 서브 관리 노드는 루트 관리 노드로부터 받은 그룹 키 부분 정보를 로컬 멤버 노드에게 전송하고 로컬 멤버 노드에 대한 신뢰성을 책임진다. 루트 관리 노드와 서브 관리 노드를 관리 노드라 한다. 관리 노드가 신뢰적인 전송을 위해 관리하는 멤버 노드는 전체 그룹에 독립적으로 유지 가능하므로 확장성 및 효율성이 좋다. 관리 노드는 동적인 그룹에 따른 타이머를 설정함으로써 손실 감지에 대한 시간을 줄임으로써 효율적인 손실 감지 및 손실 복구를 한다. 임계값 설정으로 인한 중복 수신에 대한 오버헤드를 줄일 수 있다.신뢰성을 향상 시킬 수 있는 Load Balancing System을 제안한다.할 때 가장 효과적인 라우팅 프로토콜이라고 할 수 있다.iRNA 상의 의존관계를 분석할 수 있었다.수안보 등 지역에서 나타난다 이러한 이상대 주변에는 대개 온천이 발달되어 있었거나 새로 개발되어 있는 곳이다. 온천에 이용하고 있는 시추공의 자료는 배제하였으나 온천이응으로 직접적으로 영향을 받지 않은 시추공의 자료는 사용하였다 이러한 온천 주변 지역이라 하더라도 실제는 온천의 pumping 으로 인한 대류현상으로 주변 일대의 온도를 올려놓았기 때문에 비교적 높은 지열류량 값을 보인다. 한편 한반도 남동부 일대는 이번 추가된 자료에 의해 새로운 지열류량 분포 변화가 나타났다 강원 북부 오색온천지역 부근에서 높은 지열류량 분포를 보이며 또한 우리나라 대단층 중의 하나인 양산단층과 같은 방향으로 발달한 밀양단층, 모량단층, 동래단층 등 주변부로 NNE-SSW 방향의 지열류량 이상대가 발달한다. 이것으로 볼 때 지열류량은 지질구조와 무관하지 않음을 파악할 수 있다. 특히 이러한 단층대 주변은 지열수의 순환이 깊은 심도까지 가능하므로 이러한 대류현상으로 지표부근까지 높은 지온 전달이 되어 나타나는 것으로 판단된다.의 안정된 방사성표지효율을 보였다. $^{99m}Tc$-transferrin을 이용한 감염영상을 성공적으로 얻을 수 있었으며, $^{67}Ga$-citrate 영상과 비교하여 더 빠른 시간 안에 우수한 영상을 얻을 수 있었다. 그러므로 $^{99m}Tc$-transierrin이 감염 병소의 영상진단에 사용될 수 있을 것으로 기대된다.리를 정량화 하였다. 특히 선조체에서의 도파민 유리에 의한 수용체 결합능의 감소는 흡연에 의한 혈중 니코틴의 축

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.6
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• pp.40-52
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• 2011

This paper develops a traffic condition decision algorithm to improve the reliability of traffic information on urban streets. This research is reestablished the criteria of qualitative traffic condition categorization and proposed a new qualitative traffic condition decision types and decision measures. The developed algorithm can be classified into 9 types for qualitative traffic condition in consideration of historical time series of speed changes and traffic patterns. The performance of the algorithm is verified through individual matching analysis using the radar detector data in Ansan city. The results of this paper is expected to help promotion of the traffic information processing system, real-time traffic flow monitoring and management, use of historical traffic information, etc.

• Spatial Information Research
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• v.20 no.2
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• pp.13-24
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• 2012

To prevent the damage to human health by climate change, vulnerability assessment should be conducted for establishment of adaptation strategies. In this study, vulnerability assessment was conducted to provide information about vulnerable area for making adaptation policy. vulnerability assessment for human health was divided into three categories; extreme heat, ozone, and epidemic disease. To assess vulnerability, suitable indicators were selected by three criteria; sensitivity, adaptive capacity, and exposure, spatial data of indicators were prepared and processed using GIS technique. As a result, high vulnerability to extreme heat was shown in the low land regions of southern part. And vulnerability to harmful ozone was high in the surrounding area of Dae-gu basin and metropolitan area with a number of automobiles. Vulnerability of malaria and tsutsugamushi disease have a region-specific property. They were high in the vicinity of the Dimilitarized zone and south-western plain, respectively. In general, vulnerability of human health was increased in the future time. Vulnerable area was extended from south to central regions and from plain to low mountainous regions. For assessing vulnerability with high accuracy, it is necessary to prepare more related indicators and consider weight of indicators and use climate prediction data based on the newly released scenario when assessing vulnerability.

• Journal of Climate Change Research
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• v.5 no.2
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• pp.165-178
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• 2014

National and local governmental adaptation plan for climate change will become mandatory in 2015. In order to establish the plan, assessment of vulnerability to climate change needs to be preceded. LCCGIS, a toolkit for vulnerability assessment, has been widely used by many local governments. However, assessment results by LCCGIS are not yet reliable because most of the vulnerability indices applied to LCCGIS　have the same value for almost all administrative units in Korea. In this study, proxy variables for hard-collectable indices were introduced, and the results were compared with those without any proxy variables. Vulnerability assessment could be conducted subjectively due to uncertainty. Thus, determination of objective indices, understanding the available data, and changes of indices in local conditions were organized. Results from this study are expected to make vulnerability assessment reliable and contribute to assessing vulnerability to climate change reflecting on local governmental characteristics.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2001.10a
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• pp.39-42
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• 2001

에너지 산업 환경의 변화와 정부의 공기업 평가에 대한 대응책으로 시도된 대한석탄공사(KoCoal)의 균형성과관리(Balanced Scorecard, BSC) 프로젝트는 공기업의 가치제고와 조직원들에 대한 성과 평가의 신뢰성을 제고하기 위한 노력의 일환으로 추진되었다. 본 연구에서는 대한석탄 공사가 새로운 비전과 전략으로부터 균형 잡힌 성과 영역을 판별하고 각 성과영역의 주요성공요인(CSFs) 및 주요 성과지표(KPIs)를 개발하여 연계하는 과정을 제시하고, 균형성과관리 시스템을 조직구성원의 성과 평가와 연결하는 방법을 제안한다. 또한 대한석탄공사의 균형성과관리시스템의 기대효과를 제시하고 시행상의 문제점 및 개선방안을 모색한다.

• Journal of the Korean Society for Railway
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• v.12 no.6
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• pp.1037-1042
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• 2009

Safety regulation of railway embankment is restricted by safety factor in dry season or rainy season in Korea. Safety factor which is results from the limit equilibrium analysis is varied by various external conditions. And because it has no reflection point, it is very difficult to manage the safety of trains. Safety regulation such like warning sign, reduce speed and train stop is the best choice to reduce the damage of embankments where it is worried about occurrence of disasters. In this study, additional index is proposed to support present safety standards based on unsaturated soil mechanics and reliability analysis. It is velocity of failure probability. It has an apparent reflection point near present safety regulation. It is possible to modify the regulation for safety management and monitoring system of embankments by using this index.

• Journal of Convergence for Information Technology
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• v.8 no.6
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• pp.173-186
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• 2018

While cloud services are expanding, many users are having difficulty in adopting cloud services. This is because there is no information as to which cloud services can be trusted by users. loud service level agreement (Cloud SLA) is an agreement between cloud service providers and cloud service consumers using qualitative and quantitative indicators including quality and performance, etc. of cloud services. In this study, we propose a framework for cloud SLA that can be applied to the domestic cloud industry to improve service levels for cloud service providers and to protect users and also derive the detailed components of cloud SLA applicable to the domestic cloud industry using the proposed framework. Through this result, it is expected that the government will utilize the policy to enhance the reliability between cloud service providers and users under "the Act on the Development of Cloud Computing and Protection of Users", and eventually to activate cloud services by improving the quality and performance level of domestic cloud services and building a user trust.

• Geotechnical Engineering
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• v.10 no.2
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• pp.97-108
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• 1994

A new RI calibration curve acquired from the laboratory tests on typical embankment materials is found to be adequate for testing subgrade materials in Korea but may not be suitable for testing materials containing gravels. Therefore this study aims for the modification of RI values that enables the usage of RI to all kinds of roadbed materials. Also other factors available for the criteria of compaction control such as air void ratio and degree of saturation were reviewed for their applicability.

• Management & Information Systems Review
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• v.31 no.3
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• pp.117-139
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• 2012

The purpose of this study is to examine of transparency and Corporate Social Responsibility(CSR) on financial performance and firm value. The empirical results are as follows: First, we finds that ROA showed significant effect of all transparency measures exception QAS measure and Tobin's Q showed significant effect of CITSA, SCTSA, SETR and SATSA. Second, 'Total-ROA' and 'ROA' models showed significant positive effects of lnCSR(TranD${\times}$lnCSR) and ROA, also 'Total-Tobin's Q' and 'Tobin's Q' model had same results. Consequently, this study results had that The firms with higher transparency and higher CSR exhibit better financial performance and firm value.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.8 no.2
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• pp.109-116
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• 1988

The strength and load of structure are varied with the Passage of time, and become a process of probability. It is possible to estimate the reliability from the relation between strength and load. Considering the safety, It is reasonable to estimate allowable stress from the safety factor based on the reliability. In this study, the method to estimate probability of fracture, which is index of reliability for rail subjeict to long term fatigue load were examined. In estimation of reliablity it is meaningless to evaluate numerical value especially this difficult case estimating parameter of random variable. To overcome this problem, conventional design method estimating relative reliability were proposed. In this study the Cornell method were examined. The uncertainity of random variale, ie coefficient of variation which is the index of variation of strength and load were considered. The effect of uncertainity related to probability of fracture, and safety factor based on reliability were examined. The results of this study are followed. The reliability of weld metal were influenced by variation of strength more then load, and base metal were influenced by load. It is confirmed that the allowable stress range calculating with factor of safety based an reliability is conservative.