• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2005년도 추계학술대회 논문집
• /
• pp.31-36
• /
• 2005

본 연구는 해양수산부와 해양경찰청 둥에서 관리$\cdot$운영되고 있는 해상교통안전관리체계와 첨단 정보통신기술을 이용하여 차세대 지능통합형 해상교통안전관리시스템을 구축하기 위해 필요한 기반 기술에 관한 것으로서, 해상에서의 선박교통통항 안전성을 극대화하기 위한 시스템의 필요 구성요소, 구성요소의 기능 및 기술규격 그리고 구성요소간의 연계기술 등의 표준화 방안을 구체적으로 제시하였다.

• Journal of the korean society of oceanography
• /
• 제33권4호
• /
• pp.212-218
• /
• 1998

Three different outflow boundary conditions are considered in modeling the East Sea circulation. The first one is that of the conventional constant volume transport (CT). The second one is the Orlanski radiation boundary condition (OR). The third one is that of the constant sea level just outside the outflow boundary (SL). In the third condition, the outflow current is set to be driven by the sea level differences across the outflow open-boundary lines, based on the recent knowledge that the Tsushima Current is driven by the sea level differences across the inflow and outflow boundaries. In case of OR it takes too much time to reach the steady state, resulting in a large increase of Tsushima Current Water in the basin and low level of kinetic energy. Both CT and SL reach the steady state in a relatively short time. However, SL is more recommendable, because it is based on physical background and generates less numerical noises than CT.

• 한국CDE학회논문집
• /
• 제18권6호
• /
• pp.399-406
• /
• 2013

This paper describes a new simulation technique for advection-diffusion phenomena over the sea surface using the lattice Boltzmann method (LBM), capable of predicting oil dispersion from tankers. The LBM is used to solve the pollutant transport problem within the framework of the ocean environment. The sea space is represented by the lattices, where each lattice has the information on oil transportation. Since dispersed oils (i.e., oil droplets) at sea are transported by convection due to waves, buoyancy, and turbulent diffusion, the conservation of mass and many physical oil transport rules were used in the prediction model. Since the LBM is modeled using the uniform lattices and simple rules, it can be easily accelerated by the parallel mechanism, for example, GPU-accelerated method. The proposed model using the LBM is used to simulate a simple pollution event with the oil pollutants of 10,000 kL. The simulation results indicate that the LBM method accelerated with the GPU is 6 times faster than that without the GPU.

• 한국환경과학회지
• /
• 제11권10호
• /
• pp.1133-1140
• /
• 2002

The growth and extent of the local pressure field at any point is of primary importance as it supplies the driving force for the local wind circulation which causes a medium-range transport of air pollutants. The local pressure field is produced by the variation of temperature in the lower layers of the atmosphere, and is called the thermal wave. The thermal wave is influenced by the difference in the diurnal variations between two regions with different surface condition, for example land and sea. This difference produces the land- and sea-breeze phenomenon, and brings corresponding variations in the form of the thermal wave. Daytime temperature over the inland area (Daegu) was higher than that of the coastal area (Busan). The temperature difference reached about 5~6$^{\circ}C$ in the late afternoon(30-31 May 1999). The low pressure system of Daegu was most fully developed at the time. In this study, we investigated the possibility of thermal low onset around Daegu in summer with an analytical model. The topography effect was neglected in the model. We could predict a thermal low-pressure of about 3.4hPa at Daegu with wide flat land surface, when the inland area is about 6K warmer than the coastal area temperature. The pressure decrease is somewhat less than the observed value(4~5 hPa).

• 유통과학연구
• /
• 제21권8호
• /
• pp.23-34
• /
• 2023

Purpose: To examine the economic effects of logistics under the influence of policies. Research design, data and methodology: This study is the first to use the panel data of 31 provinces and municipalities in China from 2012 to 2021, and use the OLS and DID models to evaluate whether the New Western Land-Sea Corridor (NWLSC) has promoted the economic development of the regions along the corridor. Results: The NWLSC has stimulated local economic growth by promoting the development of transportation, postal, and telecommunications industries along the corridor. Further, considering the locational differences of the regions along the NWLSC, we examined the differences in economic effects between regions along the Yangtze River and those not along the Yangtze River under the background of NWLSC implementation. We found that waterway and airway transport located along the NWLSC and in the Yangtze River Economic Belt (YREB) region can significantly promote economic growth. However, for regions located along the NWLSC but not in the YREB region, the impact of roadway, railway, and airway transport in these regions on economic growth is more significant. Conclusions: This study has important reference value on how to use logistics to promote the economic and cross-border commerce development of landlocked countries or regions.

• 한국지구과학회:학술대회논문집
• /
• 한국지구과학회 2005년도 추계학술발표회 논문집
• /
• pp.161-162
• /
• 2005

• Ocean and Polar Research
• /
• 제30권1호
• /
• pp.21-31
• /
• 2008

Analyzing the results of East Sea Regional Ocean Model using a 3-dimensional variational data assimilation scheme, we investigated spatial and temporal variability of the North Korean Cold Current (NKCC) in the East Sea. The climatological monthly mean transport of the NKCC clearly shows seasonal variation of the NKCC within the range of about 0.35 Sv ($=0^6m^3/s$), which increases from its minimum (about 0.45 Sv) through December-January to March, decreases during March and May, and then increases again to the maximum (about 0.8 Sv) in August-September. The volume transport of the NKCC shows interannual variation of the NKCC with the range of about 1.0 Sv that is larger than seasonal variation. The southward current of the NKCC appears often not only in summer but in winter as well. The width of the NKCC is about 35 km near the Korean coast and its core is located under the East Korea Warm Current. The North Korean Cold Water (NKCW), characterized by low salinity and low temperature, is located both under the Tsushima Warm Water and in the western side of the maximum southward current of the NKCC that means the NKCC advects the NKCW southward along the Korean coast. It is revealed that the intermediate low salinity water, formed off the Vladivostok in winter, flows southward to the south of $37^{\circ}N$ through $2{\sim}3$ paths; one path along the Korean coast, another one along $132^{\circ}E$, and the middle path along $130^{\circ}E$. The path of the intermediate low salinity varies with years. The reanalysis fields suggest that the NKCW is advected through the paths along the Korean coast and along $130^{\circ}E$.

• 한국수자원학회논문집
• /
• 제37권2호
• /
• pp.97-108
• /
• 2004

최근 들어 도서지역이나 해안지역의 제한된 수자원을 보다 효과적으로 사용하기 위하여 지하댐을 이용한 지하수자원 개발 방안이 제시되고 있다. 그러나 해안선에 인접한 지하댐의 경우 과도한 지하수 양수는 대수층의 지하수위를 저하시켜 결국 염수침입이라는 심각한 문제를 발생시키게 된다. 염수침입은 대수층의 지하수위 하강에 기인하므로 본 연구에서는 지하댐 하류에 함양정(Recharging well)을 설치하여 대수층의 지하수위를 상승시킴에 따른 염수침입 저감효과를 분석하였다. 이 방안을 쌍천유역에 적용하였으며, 이를 위해 염분의 이송ㆍ확산을 분석할 수 있는 SUTRA(Saturated-Unsaturated Transport) 수치모형을 적용하였다. 그 결과 지하댐 하류지역에 대한 함양기법이 양수정 염분 저하에 매우 효율적인 방법임이 증명되었고, 염해저감을 위한 함양정 운영시 차수벽으로부터 40∼60m거리에 함양정을 설치하고 함양률을 총 양수량의 6∼7％정도로 하여 운영을 할 때 가장 효율적으로 염해를 저감시킬 수 있다는 결론을 얻을 수 있었다.

• 한국수산과학회지
• /
• 제52권6호
• /
• pp.666-684
• /
• 2019

The horizontal distributions of eggs and larvae of chub mackerel Scomber japonicus were extensively surveyed in the vicinity of Korean waters between 31°75'N and 36°50'N during May and June in 2016 and 2017 (total of four surveys). We used a coupled bio-physical model (DisMELS) that combines an individual-based model (IBM) incorporating vertical migration of larvae and temperature-dependent survival to understand transport processes in the early life stage. Using the distributions of eggs and larvae from surveys, the potential spawning grounds were estimated at the northwest and southeast of Jeju Island and the central East China Sea in May, and at the southwestern East Sea and southern West Sea in June by running the model backward in time. In forward experiments within 30 days from the backward results, most larvae were transported to both the Korean and Japanese sides of the East Sea through the Korea Strait. However, the larvae released in the central East China Sea were transported to the Japanese side only, while those released in the southern West Sea were retained within that region. The survival rates at 30 days after release based on the simulation incorporating temperature-dependent survival throughout May and June were 29.7% in 2016 and 28.8% in 2017.

• 한국해양학회지:바다
• /
• 제24권3호
• /
• pp.439-447
• /
• 2019

지금까지의 연구 결과를 토대로 하여 대마난류의 순환역학에 관한 몇 가지 쟁점들을 정리해 보고 향 후 해결할 문제점들을 짚어보는 기회로 삼고자 하였다. 주요 관심 사항은 대마난류의 형성, 그 수송량의 계절변동 및 동해 내부에서의 분지 현상이다. 대마난류는 북태평양 아열대순환의 일부로서 북태평양 전지구적 바람장에 의해 형성된다. 그러나 마찰, 만의 지형, 장벽효과 등에 따라 그 수송량은 민감하게 변한다. 수송량의 계절변동에 대해서는 여러 학자들에 의해 많은 요인들이 제시되어 왔으나 아한대 바람장이 이와 가장 밀접히 연관되어 있는 것으로 밝혀졌다. 그러나 향후, 아한대 바람장 뿐만 아니라 아열대 바람장까지를 포함한 북태평양 전체 바람장과의 관계를 보여줄 수 있는 연구가 필요해 보인다. 대마난류의 두 분지인 동한난류와 일본연안류의 형성 기작으로서 그동안 서안강화 현상과 해저지형 효과가 가장 유력하게 제시되어 왔다. 그러나 서안강화는 동한난류의 계절변동을 설명할 수 없다는 문제점을 갖고 있음으로 이를 대체할 다른 기작에 대한 연구가 필요하다고 사료된다.