• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.9
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• pp.1931-1938
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• 2012

A by-pass path in wireless sensor networks is the alternative path which be able to forward data when a routing path is being broken. One reason of depleting energy is occurred by the path. The method for solving prior to addressed the problem is proposed. However, this method may deplete radio resource. The best path has advantage that network lifetime of sensor nodes is prolonged; on the contrary, in order to maintain the best path it have to share their information between the entire nodes. In this paper, we propose the best path searching algorithm in the distributed three dimensional sensor networks. Through the neighboring informations sharing in the proposed method, the proposed algorithm can decide the best k-path as well as the extension of network lifetime.

• Transactions of the Korean hydrogen and new energy society
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• v.28 no.6
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• pp.649-656
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• 2017

At present, hydrogen is emerging as a future energy source based on environment-friendly aspect, creation of new industry, and enhancement of domestic energy security. In accordance with it, the world's leading automobile companies are focusing on the development and commercialization of hydrogen electric vehicle technology, and each country is strengthening its hydrogen fueling station deployment strategy for its own country. Furthermore, the supply of hydrogen fueling stations is actively promoting under national support. More than 500 hydrogen fueling stations are being constructed, operated and planned around the world. The introduction of hydrogen energy is also progressing in Korea, by announcing road-map to supply hydrogen electric vehicles and hydrogen fueling stations by year. However, there is insufficient discussion on the capacity of hydrogen fueling station in Korea. Therefore, this study suggests the optimum capacity of hydrogen fuelling station for domestic hydrogen economy.

• Journal of Energy Engineering
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• v.28 no.4
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• pp.48-60
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• 2019

After the Paris Agreement in 2015, the government has been promoting various policies such as 'Hydrogen-Economy Roadmap(2019)' to supply hydrogen. As part of this, the government announced the goal of building 310 hydrogen refueling stations(HRS) until 2022. To this end, special case standard for the introduction of complex, packaged, and mobile hydrogen refueling stations(MHRS) have been enacted and promulgated. The MHRS has the advantage of being able to supply hydrogen to multiple regions. However, due to the movement and close distance between facilities, it is necessary to secure proper installation standards and operational safety through safety analysis. In this study, the possibility of introduction was investigated by designing a standard model and quantitative risk assessment(QRA). As a result of QRA, personal and social risk were acceptable, and the empirical test direction and implications were derived.

• Journal of Energy Engineering
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• v.24 no.4
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• pp.130-139
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• 2015

Korea country was set up over 30% greenhouse gas reduction target in comparision with BAU(Business as usal) at the national level, depending on climate change, which have been promoted as several technical and policy planning in order to reduce national greenhouse gas reduction. In this study, we derived the policies and technologies of power plant sector that is a high rate of reduction and public interest, we established a model for a common evaluation indicators and each of the evaluation factors between policy and technology priorities based on appropriate subject experts using analytic hierarchy process(AHP). Further we suggest insight to electricity company to establish the investment strategies of the technology and the associated policy by applying a weight evaluation index presenting a comprehensive priority.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.5B
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• pp.557-565
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• 2011

In this paper, we assume that sensor nodes organize the multi-hop networks, are fixed, and operate as full function devices(FFD). The wireless sensor network(WSN) only consists of mobile nodes without the assistance from the fixed infrastructure, which increases the flexibility of the network. However, it is difficult to perform routing in the WSN, since sensor nodes freely join in and drop out of the network, and some sensor nodes have very low power. We propose the algorithm combining routing schemes based on the bitmap and cluster methods in this paper. Through computer simulations, we show the validity of the proposed algorithm.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.2
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• pp.249-253
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• 2013

This study analyzed that technological competition, variety and simility of Green IT fields using patents data. To achieve this, we limited range of Green IT that reduction of energy, eco-friendly technology. Therefore we conducted analysis of patents that power saving systems, light control system, smart system, cloud computing and green house/eco systems. As the result of that, power saving field was the most developed. The simililarty of power saving and cloud computing systems are very high and similiarities of light control system, green house/eco systems and smart system were very high.

• Proceedings of the Korea Contents Association Conference
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• 2019.05a
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• pp.325-326
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• 2019

서비스화(servitization)와 공유경제 패러다임이 확산되면서 서비스 산업에서도 IT기술을 융합시킨 다양한 형태의 새로운 비즈니스가 성공적으로 정착되고 있다. 특히 대중교통 서비스 산업에서 우버(Uber) 택시는 IT기술과 공유경제 개념을 절묘하게 접목시킨 새로운 차원의 성공적인 공유택시 비즈니스 모델로 자리매김하였고, IT기술을 적용한 교통예약 소프트웨어는 공유택시의 차별적 경쟁우위를 확보하기 위한 중요한 수단이 되고 있다. 공유택시 예약 프로그램은 택시이용자에게 신속하고 편리함을 제공할 뿐만 아니라 에너지 절약, 교통체증으로 인한 스트레스 완화 등의 많은 사회적 혜택과 이익을 제공하고 있기 때문에, 여러 분야에서 다양한 연구가 진행되고 있다. 최근 중국에서는 보다 진보된 공유택시 예약 프로그램이 공유택시에 접목되면서 공유택시 이용객이 급히 증가하고 있으며, 이와 함께 공유택시 차별화에 핵심적인 역할을 하는 소프트웨어 시장의 경쟁도 가속화 되고 있다. 그러나, 이용객을 대상으로 강력범죄 발생빈도 증가와 이로 인한 부정적인 여론의 급속한 확산은 공유택시 산업발전에 심각한 방해요인이 되고 있지만, 근본적인 해결방법에 관한 연구는 미비한 실정이다. 따라서 본 연구는 공유택시 예약 프로그램에 이용객의 안전을 위한 컨텐츠 개발과 적용을 통해 공유택시 이용객의 불안해소와 공유택시 산업 발전에 기여할 수 있는 방법을 제안하고자 하였다. 연구방법은 중국현지의 공유택시 이용객을 대상으로 실증연구를 진행할 계획이며, 고객여정맵(CJM)과 Kano 분석을 통해 결과와 시사점을 도출할 계획이다.

• Journal of the Korean Institute of Gas
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• v.25 no.1
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• pp.1-6
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• 2021

Based on Korea's Hydrogen Economy Activation Roadmap, an annual supply of 5.26 million tonnes of hydrogen is required by 2040. But if the hydrogen production from byproduct, extraction, and electrolysis of water is not able to meet the target which is 50% of total production, it would be necessary to increase the portion of imported hydrogen. Therefore, it is essential to secure a variety of sources for overseas production. In this technical report, hydrogen production/transportation policies, current condition, and future prospects of Canada, a major supply candidate, is examined and an example of blue hydrogen project which is considered the most realistic hydrogen supply method is introduced.

• Journal of Navigation and Port Research
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• v.35 no.1
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• pp.57-62
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• 2011

On the view point of renewable energies as energy sources of district heating and cooling plant, the purpose of this study is to develop, classify and map the 500m${\times}$500m mesh, of which is treated as normal size in DHC regulations for evaluation process. Followings are the results. Various building and geographical informations including 13 districts and 108 counties are re-defined to create 500m${\times}$500m meshes, and it is find out that 3,289 meshes among 8,463 meshes have meaningful floor areas. Only 59 meshes(1.8%) are evaluated as mesh which has more than 50% of building volume ratio per mesh. 5 clusters classified by principal analysis and cluster analysis with building needs' characteristics are defined. Gwang-an Dong is representative of cluster 1 characterized as commercial area, and the cluster 4, 5 which has mainly residential needs are distributed in Yong-ho dong. Because there are a lot of cluster 3 meshes, which has complex needs area based on residential, cluster 3 could be defined as representative of Busan metropolitan city.

• Journal of Animal Environmental Science
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• v.17 no.sup
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• pp.1-6
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• 2011

Korean Government announced 'The Roadmap to realize a low carbon green society on year 2020' on July 12, 2011 in order to mitigate greenhouse gas (GHG) emissions. Non-energy category of Food, Agriculture, Forestry and Fishery (FAFF) should mitigate 1,349 kilo $CO_2$-equivalent ($CO_2$-eq.) tonnes which is 7.1% of Business-As-Usual on year 2020. The mitigation from animal manure treatment system (AMTS) comprises ca. 45% of the total mitigated amount of Non-energy category of FAFF. Hence, the precise evaluation of GHG emissions from AMTS is important to find effective mitigation measures. Life cycle assessment was used to evaluate GHG emissions from AMTS. The most GHG emitter was a composting/liquid fertilizer/activated sludge system (1,649.45 kg $CO_2$-eq./head/year) and the least GHG emitter was a activated liquid fertilizer system (1,024.46 kg $CO_2$-eq./head/year). Thermophilic oxic process showed the highest ratio (34.9%) of GHG emissions by the use of electricity to total GHG emissions from systems. Energy efficiency should be considered to mitigate GHG emissions from AMTS.