• Proceedings of KOSOMES biannual meeting
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• 2018.06a
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• pp.154-154
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• 2018

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.2
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• pp.595-608
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• 2013

This paper is proposed the computation method of moored ship motion considering harbor resonance, and estimated that the harbor resonance have an effect on moored ship motion. The computation of harbor resonance was used CGWAVE model and the computation of moored sip motion was used the Green function method expressed by three dimensions. This method was verified with the field observation data of moored ship motion, and the application of actual harbor was investigated with wave field data and down time record data in Pohang New Harbor. The resonance periods in Pohang New Harbor that obtained from wave field data were 80, 33, 23, 8 minute, which are the long waves, and 42, 54, 60 second, which are the infra-gravity waves inside harbor slip. The simulated results of harbor resonance were corresponded with the wave field data. This study was investigated on 5,000 ton, 10,000 ton and 30,000 ton ship sized in Pier 8 of Pohang New Harbor that the harbor resonance has effect on moored ship motion from simulated results of ship motion in case of included resonance and excluded resonance. In case of included resonance, the ship motion have increased by 12~400 percent when compared with results of excluded resonance. We could find that the harbor resonance have still more an effect on the surge and heave motions of a large size ship and the roll and yaw motions of a small size ship.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.05a
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• pp.290-297
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• 2004

In this paper, one of the harbour maneuvering tests is described. Its goal is to investigate the so-called crabbing performance of ships. By crabbing is meant the ability of the vessel to move sideways with the use of her own maneuvering devices like propellers, rudders, transverse thruster, etc. the 3m ferry model is made by ocean engineering wide tank in the university of ulsan. when the model ship is leaving and going to the quay, Transverse forces and Yawing moments are measured, in the condition of zero longitudinal force and the design draught, by load cell attached to the longitudinal center of gravity on the ship. the purpose of the experiment is to verify the reliability of ocean wide tank in university of ulsan about crabbing test compared with results of foreign research institute.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.307-311
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• 2006

일반적으로 도달시간은 지표면 유출의 흐름상태에 의존하며, 대개 중력흐름으로 가정하여 도달시간을 산정하고 있다. 본 연구에서는 흐름상태를 중력흐름과 표면장력흐름으로 구분하고 각 흐름을 판단할 수 있는 임계치를 추정하였다. 도달시간 산정을 위해 유역경사와 지표면조고의 영향을 고려할 수 있는 무차원수를 도입하였으며, 이 임계치의 범위에 따라 중력흐름과 표면장력흐름을 구분하고 두 조건의 흐름상태에 따른 도달시간 산정식을 각각 개발하였다. 중력흐름에 의한 도달시간 산정식과 표면장력흐름에 의한 도달시간 산정식을 개발하고 검증하기 위하여 기존 외국에서 실험한 자료를 비교 분석하였다. 분석결과를 통하여 이러한 흐름특성을 고려한 도달시간 산정식을 모형에 적용할 경우 유출모형을 통한 유출량산정의 정확도 향상에 기여할 것으로 판단된다.

• Environmental and Resource Economics Review
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• v.14 no.3
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• pp.627-653
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• 2005

The paper investigates the relation between importer's environmental regulation level and export of Korea by using the gravity model. We used the trade data of OECD for the year 2001 and environmental regulation indices of WEF. The main results of these empirical analysis are as follows. First, the influence of environmental regulation on export of whole industries have a significant result. Second, this effects matters at the industry level, too. But, the effects of the environmental regulation depends on the industries.

• Proceedings of the Korean Society of Computer Information Conference
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• 2021.01a
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• pp.327-328
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• 2021

본 논문은 2014년 세월호 사고 이후 해양재난사고에 대한 국민들의 경각심이 고조되었으며 해양레저인구증가로 인한 해양사고가 증가되는 상황에서 사고예방 및 해양안전문화 고취를 위한 해양안전교육센터 구축하고자 수요추정을 수행하였다. 특히, 우리나라 대부분의 해양안전체험관과 유사한 체험관들은 대부분 전라, 경기지역에 분포하고 있어 지역 편향을 해소하는 차원에서 동남권 안전센터 구축이 필요한 상황이며 해양레저 및 해양산업의 중심이 영남권에 위치하고 있기 때문에 안전교육센터의 구축의 정책적인 타당성이 있다. 본 논문에서는 해양안전교육센터 수요추정을 중력모형을 활용하여 수행하였으며 사회경제적인 타당성의 근거로서 활용이 가능할 것으로 기대된다.

• Journal of the Korean Geographical Society
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• v.43 no.2
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• pp.202-219
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• 2008

As demand for high speed Internet service has explosively increased in the United States for the past decade, the construction or upgrades of telecommunication infrastructure has also been rapidly followed. Though currently many people in urbanized areas can be provided advanced broadband services, there are still challengeable areas to be served, such as remote or low populated areas because those areas are potentially non-profitable to commercial broadband service providers. This paper addresses the spatial disparity or in a broader term, the 'digital divide' of the broadband access by the county level in the United States. We propose the quantified measure of the county level broadband accessibility for identifying such digital divide. The developed measure is a hybrid form of the classical gravity based potential model and network topological accessibility, encouraged from the lack of prior efforts eying to explicitly incorporate the understanding of the whole process of the Internet access. The computational tasks are performed in a GIS platform, which includes several programmed functions.

• Environmental and Resource Economics Review
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• v.18 no.1
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• pp.75-103
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• 2009

The hypothesis suggested by Porter and van der Linde claims that innovating firms operate in a dynamic competitive situation which allows global diffusion of environmental-friendly technologies. Therefore, countries that are subjects to more stringent environmental regulations may become net exporters of environmental technologies. In the context of Porter hypothesis, this study investigates the impact of importing countries' environmental regulation on Korea and Japan's export flows of technologies for renewable energies and energy efficiency by estimating the gravity equation. The estimation result shows that : (1) our results are consistent with the Porter hypothesis where environmental regulation represents a significant source of comparative advantages, (2) Korea's export flows of technologies for renewable energies and energy efficiency with respect to the importing countries' environmental regulation are more sensitive than Japan's, and (3) the adverse relationship between export flows and importers' environmental stringency in developing countries does not hold in the renewable energies and energy efficiency related sector.

• Journal of Technology Innovation
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• v.25 no.2
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• pp.127-152
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• 2017

With the advent of the WTO system in 1995, non-tariff barriers including technical barriers to trade(TBT) has become one of the important issues in world trade order. The purpose of this study is to analyse an impact of the calibration and measurement capabilities(CMC), the degree of equivalence of national measurement standards which is maintained by NMIs to provide governments with a technical foundation for wider agreements related to international trade. The results of the analysis using the gravity model with the proxy of the CMC shows that the CMC has a positive impact on Korean trade. Particularly, it was estimated that the CMC registered by high-income economies has more impact on Korean trade than those by low income economies. This implies that the countries highly dependent upon foreign trade like Korea need to have much more interest in the investment into measurement standards and science which is generally considered to be a public goods.

• Spatial Information Research
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• v.17 no.3
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• pp.251-259
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• 2009

As a result of the current trend towards promoting conservation of the ecosystem, there have been various studies conducted to determine ways to establish an ecological network. The development of analytical methods and an environmental database of GIS has made the creation of this network more efficient. This study focuses on the development of an urban spatial decision support system based on 'Landscape Ecology Theory'. The spatial decision support system suggested in this study consists of four stages. First, landscape patch for the core areas, which are major structures of the ecological network, was determined using the GIS overlay method. Second, a forest habitat was investigated to determine connectivity assessment. Using the gravity model, connectivity assessment at the habitat forest was conducted to select the needed connecting area. Third, the most suitable corridor routes for the eco-network were presented using the least-cost path analysis. Finally, a brief investigation was conducted to determine the conflict areas between the study result and landuse. The results of this study can be applied to urban green network planning. Moreover, the method developed in this study can be utilized to control urban sprawl, promote biodiversity.