• Journal of computational fluids engineering
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• v.20 no.2
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• pp.52-60
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• 2015

The objective of this research lies in the effect of installation parameters influencing on the wind proof performance of the coastal forest for damage prevention. The dissipation ratio of incident wind power is developed as an assessment index to make a lumped parameter study possible. From the real field data of East, West, and South Sea bounded on the Korean peninsula, single and double storied forests were modeled in three-dimensional shape with computer aided design, and so was done the artificial structures such as wind break, sand accumulating fence, and sand dune, etc With a commercial code ANSYS-CFX, the computational result from the comparison of dissipation ratio between single and double storied forest shows the effect of composition, and also the installation effect is investigated for artificial structures with optimal dimension of distance.

• Proceedings of the Korea Contents Association Conference
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• 2015.05a
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• pp.15-16
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• 2015

Measuring sensor, equipment, ICT facilities and their software have relatively short life time comparing to constructional structure so that we should exchange or fix them continuously in the process of maintenance and management. In this paper, we propose a novel design of integrated maintenance, management, and measuring monitoring system applying the concept of mobile cloud. For the sake of disaster prevention for constructional structures such as bridge, tunnel, and other traditional buildings in the village of local heritage, we analyze status of these structures in the long term or short term period as well as disaster situations. Collecting data based on mobile cloud and analyzing future expectations based on probabilistic and statistical techniques, we implement our integrated monitoring system for constructional structures to solve these existing problems. Final results of this design and implementation are basically applied to the monitoring system for more than 10,000 structures spread over national land in Korea. In addition, we can specifically apply the monitoring system presented here to a bridge of timber structure in Asan Oeam Village and a traditional house in Andong Hahoe Village to watch them from possible disasters. Total procedure of system design and implementation as well as development of the platform LinkSaaS and application services of monitoring functions implemented on the platform. We prove a good performance of our system by fulfilling TTA authentication test, web accommodation test, and operation test using real measuring data.

• Journal of the Korea Safety Management & Science
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• v.11 no.2
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• pp.77-85
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• 2009

Considering heat insulation and beautiful sight of construction, making use of exterior panels is increasing. Recently the exterior panels now are weak very much, and so in consequence of the weakness fire spreads rapidly. Compared with internal fire, external vertical fire spread rate goes rapidly and it is extensive in spread range, therefore it is dangerous very much. Accordingly, under present condition of poor standard of exterior panels, it is required to take measure to meet the appropriate situation. In this study, by making use of FDS(Fire Dynamic Simulation) program about external vertical fire of high rise building, fire behavior is searched by computer. It is important that realizing by computer fire modeling about external vertical fire must be included certainly in procedure of fire performance design in the future. In modeling program, FDS version 5 is available, and aluminium composite panel is applied in external panels. In this study, for realizing of actual fire condition, FDS is applied by details of fire scenarios considering influence of wind.

• Journal of the Korea Safety Management & Science
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• v.23 no.3
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• pp.97-102
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• 2021

This study developed a scenario to understand the reaction rate and operational time according to RTI value of rate of rise detector in each type in case of fire mattress. In the results of analyzing the reaction rate and operational time of detector in each scenario, in case when installing a single detector, the elevated temperature per minute was raised to 8℃/min ~ 9℃/min. In case when installing two detectors, it was raised to 9℃/min ~ 10℃/min. In case when installing three detectors, it was raised to 10℃/min. The horizontal distance between detector and mattress was 1.8m~2.5m. Whenever the number of detectors was increased, the horizontal distance was decreased. The operational time of detector was within maximum 540 seconds and minimum 420 seconds. As the research tasks in the future, there should be the researches on the effects of reaction rate of detector on the evacuation in case of fire through the result value of RSET by setting up the latency until the detector operates, and the researches on the safety by understanding if the operational time of detector is suitable for the evaluation standard of performance-centered design.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.176-176
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• 2023

The Tonle Sap is the richest and diverseness of freshwater ecosystem in Southeast Asia, receiving nurturing water flows from the Mekong and its immediate basin. In addition, the rapid development in the Tonle Sap Lake (TSL) Basin, and flood inundation may threaten the natural diversities and characteristics. The impacts of flood inundation in 11 sub-basins contributing to the Tonle Sap Lake were assessed using the Rainfall-Runoff-Inundation (RRI) model to quantify the potential magnitude and extent of the flooding. The RRI model is set up by using gauged rainfall data to simulate the information of river discharge and flood inundation of huge possible flood events. Moreover, two satellite precipitation products (SPPs), CHIRPS and GSMaP, within respectively spatial resolutions of 0.05° and 0.1°, are utilized as an input for the RRI model to simulate river discharge, flood depth, and flood extent for the great TSL Basin of Cambodia. This study used statistical indicators such as NSE, PBIAS, RSR, and R2 as crucial indices to evaluate the performance of the RRI model. Therefore, the findings of this study could provide promising guidance in hydrological modeling and the significant implications for flood risk management and disaster preparedness in the region.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.143-143
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• 2022

Precipitation plays an essential role in water resources management and disaster prevention. Therefore, the understanding related to spatiotemporal characteristics of rainfall is necessary. Nowadays, highly accurate precipitation is mainly obtained from gauge observation systems. However, the density of gauge stations is a sparse and uneven distribution in mountainous areas. With the proliferation of technology, satellite-based precipitation sources are becoming increasingly common and can provide rainfall information in regions with complex topography. Nevertheless, satellite-based data is that it still remains uncertain. To overcome the above limitation, this study aims to take the strengthens of machine learning to generate a new reanalysis of precipitation data by fusion of multiple satellite precipitation products (SPPs) with gauge observation data. Several machine learning algorithms (i.e., Random Forest, Support Vector Regression, and Artificial Neural Network) have been adopted. To investigate the robustness of the new reanalysis product, observed data were collected to evaluate the accuracy of the products through Kling-Gupta efficiency (KGE), probability of detection (POD), false alarm rate (FAR), and critical success index (CSI). As a result, the new precipitation generated through the machine learning model showed higher accuracy than original satellite rainfall products, and its spatiotemporal variability was better reflected than others. Thus, reanalysis of satellite precipitation product based on machine learning can be useful source input data for hydrological simulations in ungauged river basins.

• Journal of the Korea Safety Management & Science
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• v.25 no.4
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• pp.95-104
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• 2023

The purpose of this study is to propose measures to increase evacuation safety by calculating the habitable time using a fire and evacuation simulation program for the Room-escape cafe currently in operation, and comparing and analyzing it with the evacuation required time. Assuming a fire due to overheating of electric heaters in use in front of the warehouse, the habitable time was calculated through fire simulation, and the occupant's evacuation time calculated through evacuation simulation according installation of safety facilities, etc. was compared and analyzed with the habitable time. In the case of escape room cafes with safety facilities installed, evacuation safety was satisfied, but in escape room cafes without safety facilities, the evacuation safety was not secure. As a result of analyzing evacuation safety for each scenario based on the ASET analyzed in the fire simulation, it was found that in scenario 1, evacuation safety was secured and everyone successfully evacuated, while in scenario 2, no one succeeded in evacuation. These results can be said to confirm that the installation of safety facilities is very important in business establishments such as escape room cafes, which become enclosed structures when games are started.

• Journal of the Society of Disaster Information
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• v.17 no.1
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• pp.97-111
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• 2021

Purpose: It is expected that various infrastructures diagnosis equipment will be needed as infrastructures management is strengthened to implement the Framework Act on Sustainable Infrastructure Management. It is necessary for a certification system to supply certified products of a reasonable level in accordance with market requirements for various convergence equipment. This paper deals with the introduction of certification system of inspection and diagnosis equipment for infrastructure using advanced technologies. Method: The basic elements, systems and procedures of certification system were reviewed through analyzing and comparing the existing similar certification system in Korea. In addition, a survey was conducted on a catalog method and the minimum performance criterion (sampling survey and complete enumeration survey) to equipment developers (manufacturers), clients and equipment users. Result: This survey showed that clients preferred complete enumeration method on the basis of minimum performance, and equipment users also preferred complete enumeration survey and sample survey, for minimum performance, at a similar rate. On the other hand, equipment developers preferred the catalog method. Conclusion: Clients and users who are the users of the diagnostic equipment preferred the minimum performance criterion because their trust in quality is important. On the other hand, developers(manufacturers) preferred the catalog method which adopts self certification because it is regulated in developing various products. There is no specific plan for the minimum performance standards required for the introduction of the method which users demand, at present. In addition, it is not desirable to force to introduce a certification system because it requires a considerable period of study to prepare the specific standards. Therefore, it is appropriate to operate the system for a certain period of time centering around the catalog method for the stable and continuous development of the infrastructure diagnosis and test equipment market in Korea. Also, it is effective to expand and develop the certification system to the extent that it minimizes the impact on the market when specific plans for the standards are prepared in the future.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.11
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• pp.1472-1480
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• 2016

When disasters such as earthquake, flood, typhoon, fire and terrorism are occurred a video management system is required which can shoot video on the disaster site, and send it to a server located in the command center that can grasp at a glance the site conditions. In this paper, to know the performance elements information needed to construct the video management system. we presented a method of configuring an ad hoc network based on Wi-Fi direct communication. And we also evaluated the performance through built of environment for the video management system. The evaluated performance test items are 'packet flow tests according to the video compression ratios and the image sizes', 'packet flow tests according to the distance and traffic tests', 'packet flow tests according to whether LOS or not', and 'performance test of scenarios'.

• Journal of the Society of Disaster Information
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• v.13 no.2
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• pp.233-248
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• 2017

Uniform laws and regulations and reasonable design is necessary for the prevention of possible fire in super high-rise building. To this end, this study focused on super high-rise and massive building-related architectural review performance-based design (PBD) evaluation disaster impact assessment (DIA), and provided fire engineering measures for improving fire prevention on the basis of performance-based design by analyzing the buildings subject to these systems and problems in terms of contents. Above all, in the aspect of law and standard improvement, first, with regard to dual parts of two statutes though significant portion of them has the same contents in performance-based design (PBD) evaluation and disaster impact assessment (DIA), it is necessary to operate the systems after making them conform with each other and consolidating or abolishing them. Second, if it is impossible to consolidate or abolish performance-based design (PBD) evaluation and disaster impact assessment (DIA), the areas of contents of performance-based design (PBD) evaluation and disaster impact assessment (DIA) should be precisely classified and established. Next, engineering improvement measures against fire hazard in super high-rise building are as follows. First, it is necessary to revise the provisions of straight-run stairs in special escape stairs. And in case of installing a mechanical smoke exhaust system instead of smoke vent, sandwich pressurization used in the United Stated should be permitted. Second, with regard to smoke control system for special escape stairs, it was shown that there was necessity for revising the standards in order to enable air to be supplied according to section in case of fire, carrying out performance-based design, and the like from the early design stages to the completion stages. In the future, it is expected that an epoch-making contribution will be made to a decrease in casualties and property damage due to fire in case of super high-rise building where the results can be reflected after carrying out a study on maintenance and carrying out an additional study on other considerations of super high-rise building together with reflecting the improvement measures provided in the above-mentioned study.