• Journal of Korean Society for Atmospheric Environment
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• v.19 no.E2
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• pp.83-88
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• 2003

The present study details air pollution measurements in the Yellow Sea of East Asia. Large-scale air pollution was observed through satellite images and ground monitors in Chongju-Chongwon of central Korea. Evidence of a duststorm transport and resulting dustfall from the Gobi Desert in north China and Mongolia is shown. Also, transport of anthropogenic air pollutants from China to the Yellow Sea, Korea, and Japan was detected and discussed. It was found that the level of air pollution concentrations at a regional back-ground site increased 2 ∼ 4 times than the values observed with the relatively clean air, when massive air pollution from China moved to the Korean Peninsula. Satellite measurements will be useful for monitoring regional- and global-scale air pollution in the future.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09b
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• pp.1457-1457
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• 2005

• Journal of Mechanical Science and Technology
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• v.19 no.3
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• pp.913-923
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• 2005

The dynamic mixed model (DMM) combined with a box filter of Zang et. al. (1993) has been generalized for passive scalar transport and applied to large eddy simulation of turbulent channel flows with Prandtl number up to 10. Results from a priori test showed that DMM is capable of predicting both subgrid-scale (SGS) scalar flux and dissipation rather accurately for the Prandtl numbers considered. This would suggest that the favorable feature of DMM, originally developed for the velocity field, works equally well for scalar transport problem. The validity of the DMM has also been tested a posteriori. The results of the large eddy simulation showed that DMM is superior to the dynamic Smagorinsky model in the prediction of scalar field and the model performance of DMM depends to a lesser degree on the ratio of test to grid filter widths, unlike in the a priori test.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.13 no.3
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• pp.1-9
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• 2014

This study deals with development of Integrated Transportation Analysis System for Large-scale event. Based on case studies, the requirements of the system were defined and the direction of development was established. The large-scale events that require fast and accurate transportation policy were selected. The data warehouse and data mart were developed by integrating the large-scale event data and the traffic data. Business intelligence system was designed and developed users to allow timely decisions.

• Nuclear Engineering and Technology
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• v.54 no.9
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• pp.3347-3352
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• 2022

In 2013, the International Atomic Energy Agency (IAEA) changed the recommended maximum range of the Emergency Planning Zone (EPZ) to 30 km, and the Kori Nuclear Power Plant in Republic of Korea has also expanded the EPZ to 30 km, following the recommendation. As a result, metropolitan cities with a high population density are contained within the EPZ, and evacuating millions of people should be considered if the 30 km range of evacuation is to take place. This study proposes an evacuation plan using buses (public transportation) to transport people outside of the EPZ, quickly and efficiently. To verify the appropriate mode share ratio of buses that can guarantee the right of vulnerable road users and reduce traffic congestion, a model was built simulating the Kori Nuclear Power Plant in Ulsan Metropolitan City. The scenarios were established by changing the mode share ratio of buses and passenger cars by 10%. Considering a large-scale network analysis at the city level, a cell transmission model was applied to calculate the evacuation time in each scenario. The result shows that the optimal mode share ratio of buses is 40%, with a total evacuation time of 132 min, considering feasible bus fleets in Ulsan Metropolitan City.

• Journal of the Society of Disaster Information
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• v.20 no.1
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• pp.232-243
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• 2024

Purpose: Recently, large-scale forest fires caused by climate change, natural disasters, and human factors have been increasing every year in the East Coast and Taebaek Mountains region. Although forest fire extinguishing using helicopters is currently increasing, the need to introduce air force transport aircraft has continued to be raised due to the importance of early fire extinguishment to respond to large forest fires and the difficulty of extinguishing forest fires between sheep. This study seeks to present a plan for developing a post-fire management system for several aspects - achieving operational objectives, overcoming the operating environment, selecting a staging area, and efficient operation measures - to efficiently perform forest fire extinguishing missions using Air Force transport aircraft. Method: Based on literature research on forest fire extinguishing, forest fire extinguishing experiments using fixed-wing aircraft, and the operation status and operation method of forest fire extinguishing helicopters, the pros and cons of helicopter operation and the effects of large forest fire extinguishing using a large transport aircraft (C-130) Analyze the effectiveness of operation through analysis. Results: When extinguishing a large forest fire, an effective CM (Consequence Management) application plan was derived, including effective operation, control, command system, dispatch request, and forest fire extinguishment when integrating helicopter and fixed-wing aircraft (C-130). Conclusion: The application of the concept of CM (Consequence Management) is partially applied to some areas of chemical, biological, and radiological (CBRNE) protection in Korea, but efficient operation, control, and command systems are established when integrated operation of helicopters and large aircraft (C-130) in forest fire extinguishment. the concept of CM (Consequence Management), which is operated in advanced countries, was applied for safety management, dispatch requests, and forest fire extinguishing, thereby contributing to the establishment of a more advanced disaster and post-disaster management system.

• Wind and Structures
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• v.20 no.5
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• pp.643-660
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• 2015

The wind tunnel test of large-scale sectional model and computational fluid dynamics (CFD) are employed for the purpose of studying the aerodynamic appendices and mechanism on suppression for the vortex-induced vibration (VIV). This paper takes the HongKong-Zhuhai-Macao Bridge as an example to conduct the wind tunnel test of large-scale sectional model. The results of wind tunnel test show that it is the crash barrier that induces the vertical VIV. CFD numerical simulation results show that the distance between the curb and crash barrier is not long enough to accelerate the flow velocity between them, resulting in an approximate stagnation region forming behind those two, where the continuous vortex-shedding occurs, giving rise to the vertical VIV in the end. According to the above, 3 types of wind fairing (trapezoidal, airfoil and smaller airfoil) are proposed to accelerate the flow velocity between the crash barrier and curb in order to avoid the continuous vortex-shedding. Both of the CFD numerical simulation and the velocity field measurement show that the flow velocity of all the measuring points in case of the section with airfoil wind fairing, can be increased greatly compared to the results of original section, and the energy is reduced considerably at the natural frequency, indicating that the wind fairing do accelerate the flow velocity behind the crash barrier. Wind tunnel tests in case of the sections with three different countermeasures mentioned above are conducted and the results compared with the original section show that all the three different countermeasures can be used to control VIV to varying degrees.

• Journal of the military operations research society of Korea
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• v.25 no.2
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• pp.1-14
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• 1999

Metamodels using response surface methodology (RSM) are used for the optimality analysis of linear programming (LP). They have the form of a simple polynomial, and predict the optimal objective function value of an LP for various levels of the constraints. The metamodelling techniques for optimality analysis of LP can be applied to large-scale LP models. What is needed is some large-scale application of the techniques to verify how accurate they are. In this paper, we plan to use the large scale LP model, strategic transport optimal routing model (STORM). The developed metamodels of the large scale LP can provide some useful information.

• Journal of the Korean earth science society
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• v.28 no.1
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• pp.123-135
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• 2007

Five episodes of the large-scale transport of air pollutants in East Asia and its inflow into the Korean Peninsula have been analyzed through satellite and ground observations. These episodes include regionally polluted continental airmass, which is created by the pollutants produced in the cities and the industrial regions in China, to land on or pass through the Korean Peninsula by way of the Yellow Sea. The analysis of the NOAA satellite observation data made it possible to create images by combining 3 channels of visible and infrared ray ranges and also to identify the distribution and the transport of the air pollution mass over the Yellow Sea. The ground observation data of the air pollutants gathered in Chongwon were found highly valuable in verifying the information in comparison with ones from the satellite. Especially, regarding the episodes of large-scale transport of the air pollutants, the difference of concentration between $PM_{10}\;and\;PM_{2.5}$ was found small with the increase of $PM_{2.5}$ value. The concentration of $PM_{10}$ in the episode of yellows and, however, was found much higher than that of $PM_{2.5}$. In the episode of 27 January 2006, the inflow of the regionally polluted continental air mass into the central and southwestern region of the Korean Peninsula was observed sequentially in the various ground observatories as well as by the satellite. The north-northwest airflow dissipated the clouds over from Mt. Halla in Jeju Island up to far downwind, reduced air pollution, and created von $K\acute{a}rm\acute{a}n$ vortex.

• Proceedings of the KSRS Conference
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• v.1
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• pp.360-363
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• 2006

The red tide related with Cochlodinium Polykrikoides bloom has been frequently occurred around the South Sea of Korea and caused the economic loss in the coastal breeding grounds. The outbreak scale was usually change by physical, biological and environmental condition at each years. Relatively large-scale red tide occurred in 1995, 1997, 1999, 2001, 2002 and 2003 through spatial scale, duration and maximum density. Compared the scale of red tide with physical condition around the South Sea, the lower coastal temperature on August around the South Sea corresponded with the large scale red tide. By serial oceanographic investigations on August in the South Sea and estimated wide area temperature information by satellite, SSTA around the South Sea and wide area was negative when the outbreak of red tide was large scale. From the results of temperature difference between surface and 30m layers, the occurrence of enormous red tide has a tendency when the temperature gradient around the seasonal thermocline was weakened. Larger Kuroshio volume transport in the upstream was also corresponded with the large scale red tide.