• Journal of Information Processing Systems
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• 제5권4호
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• pp.221-228
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• 2009

Due to low cost, low-power, and scalability, ZigBee is considered an efficient wireless AMR infrastructure. However, these characteristics of ZigBee can make the devices more vulnerable to unexpected error environments. In this paper, a fault-tolerant wireless AMR network (FWAMR) is proposed, which is designed to improve the robustness of the conventional ZigBee-based AMR systems by coping well with dynamic error environments. The experimental results demonstrate that the FWAMR is considerably fault-tolerant compared with the conventional ZigBee-based AMR network.

• 한국항공우주학회지
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• 제38권9호
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• pp.900-906
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• 2010

항공기 설계검증 체계를 갖추기 위한 투자 및 인프라개발, 그리고 이 과정에 동반되는 항공기개발의 경제적인 타당성을 분석하였다. 투자와 항공기 양산판매만을 고려한 현금흐름분석에서는 음의 순현재가치가 산정되어 경제적 타당성이 부인되었으나, 수출효과, 수입대체효과 및 사고감소효과를 감안할 때에는 순편익이 투자액의 3-5배에 달하는 것으로 평가되었다. 편익의 전유성이 매우 낮다는 점을 감안할 때 이 투자는 정부가 주체가 되어 실행하여야 하며, 재정지출의 경제적 타당성이 충분한 것으로 확인되었다.

• Journal of Communications and Networks
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• 제14권3호
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• pp.319-335
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• 2012

In this study, we design an applicable model enabling internet protocol television (IPTV) service providers to use a virtual network (VN) for IPTV service delivery. The model addresses the guaranteed service delivery, cost effectiveness, flexible control, and scalable network infrastructure limitations of backbone or IP overlay-based content networks. There are two major challenges involved in this research: i) The design of an efficient, cost effective, and reliable virtual network topology (VNT) for IPTV service delivery and the handling of a VN allocation failure by infrastructure providers (InPs) and ii) the proper approach to reduce the cost of VNT recontruction and reallocation caused by VNT allocation failure. Therefore, in this study, we design a more reliable virtual network topology for solving a single virtual node, virtual link, or video server failure. We develop a novel optimization objective and an efficient VN construction algorithm for building the proposed topology. In addition, we address the VN allocation failure problem by proposing VNT decomposition and reconstruction algorithms. Various simulations are conducted to verify the effectiveness of the proposed VNT, as well as that of the associated construction, decomposition, and reconstruction algorithms in terms of reliability and efficiency. The simulation results are compared with the findings of existing works, and an improvement in performance is observed.

• 한국BIM학회 논문집
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• 제8권4호
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• pp.41-48
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• 2018

Recent technological improvements have made abundant changes in construction industry. In specific, some technical applications, such as Building Information Modeling (BIM) opens up many possibilities. Some studies have articulated the use of BIM and its advantages in construction, but most of them are theoretical, not practical. This study is to provide an insight to such obstacles in BIM research. By investigating a real project that could utilize BIM in planning and construction phases, the authors try to investigate a possible outline of advantages in BIM implementation. The study area was set to a railway construction site in South Korea. The site covers a multiple railway tracks, stations, telecommunication facilities, infrastructure facilities, railway structures, and so numerous. In the site, the authors have identified 12 errors in 7 projects that could be prevented if BIM was utilized before the construction.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.1528-1533
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• 2009

Infrastructure is provided to the user through long-term project period and large-scale working expenses. Existing facilities are getting old as time goes by. Accordingly, proper maintenance is required and generally more maintenance cost than initial invested cost is needed during life cycle. Therefore, a specific plan that just increases the value of facilities is required by evaluating performance of facilities and inputting minimum maintenance cost. Value engineering that increases the value of object by systemically analyzing Life Cycle Costs and function is actively promoted at the design phase of construction. These efforts can increase the performance of facilities at the maintenance phase of infrastructure. This study is to search how to evaluate the performance of Roadway by utilizing function analysis, as a core part of VE in the maintenance phase. In order to this a new evaluation criteria were proposed by adding an evaluation items to the existing criteria through the research of old documents, status of roadway maintenance and function analysis of VE. The results of this study may promote the effective performance evaluation to determine a resolution of roadway congestion in future. A succeeding study using the proposed evaluation criteria will be required.

• 한국관개배수논문집
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• 제18권2호
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• pp.33-42
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• 2011

Climate change has impacts on not only the average temperature rise but also the intensity and frequency of extreme events such as flood and drought. It is also expected that the damages on agricultural infrastructure will be increased resulting from increased rainfall intensity and frequency caused by climate change. To strengthen the climate change adaptation capacity, it is necessary to identify the vulnerability of a given society's physical infrastructures and to develop appropriate adaptation strategies with infrastructure management because generally facilities related to human settlements are vulnerable to climate changes and establishing an adaptive public infrastructure would reduce the damages and the repair cost. Therefore, development of mitigation strategies for agricultural infrastructure against climatic hazard is very important, but there are few studies on agricultural infrastructure vulnerability assessment and adaptation strategies. The concept of vulnerability, however, is difficult to functionally define due to the fact that vulnerability itself includes many aspects (biological, socioeconomic, etc.) in various sectors. As such, much research on vulnerability has used indicators which are useful for standardization and aggregation. In this study, for the vulnerability assessment for agricultural infrastructure, 3 categories of climate exposure, sensitivity, and adaptation capacity were defined which are composed of 16 sub-categories and 49 proxy variables. Database for each proxy variables was established based on local administrative province. Future studies are required to define the weighting factor and standardization method to calculate the vulnerability indicator for agricultural infrastructure against climate change.

• 산업융합연구
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• 제18권6호
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• pp.27-32
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• 2020

최근 IT를 활용한 비즈니스가 급증함에 따라 복잡해진 IT 인프라를 운영 관리하는데 있어 많은 예산이 소요되고 있다. 이에 대한 효율적이고 비용절감 효과를 얻을 수 있는 새로운 IT 인프라 기술이 필요한 실정이다. 본 논문에서는 정보 시스템의 단순화와 운영 관리의 효율성 및 비용 절감을 위한 IT 인프라 방식인 CI(Converge Infrastructure)과 HCI(Hyper Converge Infrastructure) 방식을 소개한다. 또한 새로운 IT 인프라 기술인 HCI 방식을 활용한 정보 시스템 및 재해 및 장애 발생 시 서비스의 연속성을 제공하기 위한 재해복구시스템의 구축 방안에 대해서 제시한다. HCI 방식을 활용하기 위한 주요 기술 소개와 함께 HCI 도입 전후의 정보 시스템실의 면적 및 소비전력, 운영의 효율성 등을 비교분석 한다.

• International Journal of Railway
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• 제6권4호
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• pp.160-168
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• 2013

A spiral lattice girder-reinforced Bi-block sleeper which has enhanced durability against increasingly growing impact force and vibration by wheel load and improved structural performance while train runs at 350km/h high speed is hereby proposed. The section of a spiral lattice girder has stable and superior structural performance thanks to its confinement effect. To compare and analyze the structural performance of spiral lattice girder-reinforced bi-block sleeper, strain and stress distribution were evaluated after applying same load condition as existing triangular lattice girder-reinforced biblock sleeper, and to compare the structural performance of triangular lattice girder and spiral lattice girder, structural analysis of lattice girder was performed separately. As a result, a spiral lattice girder proved to have had superior structural characteristics to bi-block sleeper, and furthermore as a result of evaluating the fastener interface and constructibility with shape-improved lattice girder, no interference with existing railroad structure was found and in terms of cost efficiency, a spiral lattice girder appeared to be superior to existing lattice girder.

• 정보보호학회논문지
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• 제20권5호
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• pp.111-124
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• 2010

원격 검침 시스템(AMI : Advanced Metering Infrastructure)은 최근 활발히 추진 중인 스마트그리드의 핵심 인프라로, 구축비용 절감 및 운영의 효율성을 위해 무선 통신 기술 도입이 적극적으로 검토되고 있다. 하지만, AMI에 무선 통신 기술 적용 시 무선 통신의 보안 취약점 때문에 다양한 보안 위협이 발생 가능하기 때문에 이에 대한 대응책이 필요하다. 본 논문에서는 Binary CDMA 망을 이용한 AMI 네트워크 무선망 구조를 제시하고, 이에 대한 보안 대책으로 BSIM(Binary Subscriber Identity Module)을 중심으로 사용자 인증 및 무선 구간 암호화를 수행함으로써 AMI 무선 구간의 보안 위협을 감소시키는 방안에 대해 연구한다.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.353-359
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• 2005

The infrastructure in korea has been improved drastically since July 7th, 1970 which was the first highway completed date in Korea (Seoul-Pusan). This is one of the major factors for the competitiveness of a country. Now the total length of highway in Korea is more than 2000km. However Korea is 11th in the trade volume in the world, the SOC level of Korea is around 20th at most in the world (IMD 2004). The infrastructure in Korea comparing other developed countries is far below, which gives the impact of cost of goods, even twice expensive in transporting goods through highways, railways and ports etc. Now the government budget is gradually spending more for welfare and health care side. The most of additional expense of welfare is increasing rather than SOC budget is decreasing or staying as it is as 2003. The government may think that the level of SOC is enough in point of view of preference input of budget such as welfare and health care etc. However the SOC level in Korea is far form the competitiveness of the country. The main points of this paper is to show that where Korea is in point of SOC level to go for developed country, and what to do to facilitate BOT, BTO and BTL projects. Korean government has tried to improve the practice of PPI (Private Participation of Infrastructure) with the Act on Private Capital Inducement in 1994 and the Act on Private Investment in 1997.