• Journal of Korea Water Resources Association
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• v.54 no.7
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• pp.535-544
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• 2021

Agricultural water occupies 48% of water demand, and management of agricultural reservoirs is essential for water resources management within agricultural basins. For more efficient use of agricultural water, monitoring the distribution of water resources in agricultural reservoirs and agricultural basins is required. Therefore, in this study, three threshold determination methods (i.e., fixed threshold, Otsu threshold, Kittler-Illingworth (KI) threshold) were compared to detect terrestrial water bodies using Sentinel-1 images for 3 years from 2018 to 2020. The purpose of this study was to evaluate methods for determining threshold values to more accurately estimate the reservoir area. In addition, by analyzing the relationship between the water surface and water storage at the Edong, Gosam, and Giheung reservoirs, water storage based on the SAR image was estimated and validated with observations. The thresholding method for detecting a waterbody was found to be the most accurate in the case of the KI threshold, and the water storage estimated by the KI threshold indicated a very high agreement (r = 0.9235, KGE' = 0.8691). Although the seasonal error characteristics were not observed, the problem of underestimation at high water levels may occur; the relationship between the water surface and the water storage could change rapidly. Therefore, it is necessary to understand the relationship between the water surface area and water storage through ground observation data for a more accurate estimation of water storage. If the use of SAR data through water resources satellites becomes possible in the future, based on the results of this study, it is judged that it will be beneficial for monitoring water storage and managing drought.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.3
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• pp.263-270
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• 2013

Recently, the prediction and analysis technology of marine environment are actively being studied since the ocean resources in the world is taken notice. The prediction of marine disaster by automatic collecting marine environment data and analyzing the collected data can contribute to minimized the damages with respect to marine pollution of oil spill and fisheries damage by red tide blooms and marine environment upsets. However the studies of the marine environment monitoring and analysis system are limited in South Korea. In this paper, we study the marine disasters prediction system model to analyze collection marine information of out sea and near sea. This paper proposes the models for the marine disasters prediction system as communication system model, a marine environment data monitoring system model, prediction and analyzing system model, and situations propagation system model. The red tide prediction model and summarizing and analyzing model is proposed for prediction and analyzing system model.

• Korean Security Journal
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• no.33
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• pp.137-161
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• 2012

There are some common and broad trends in National crisis management system around the world. This article considers that paradigm theoretically. 1) a shift from civil defense to civil protection, 2) 10 principles in sustainable National crisis management system, 3) the collaborative governance of crisis management. Some civil defense problems in National crisis management system are as follows; 1) obscurity of organizational identity through twofold function in civil defense, 2) ineffective organization in civil defense and disaster management system, 3) weakness of competencies in local government, 4) overlook of actual condition in communities and civil defense resources. This article suggests that to provide retired and active private security practitioners, retired law enforcement personnel, and retired military personnel to form a elite civil defense force and to find creative ways to address this pervasive threat which one reasonable and affordable solution would be for the government to take advantage of an existing resource.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.1
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• pp.34-39
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• 2015

KCG, responsible Agency of maritime SAR operation has been known to address the marine casualties well, however, it was criticized because KCG failed to take prompt and effective response to the recent Ferry disaster at the very early stage. In this regards, the authors analyze the characteristics of marine incident with historical data, and also review and examine the national SAR system focusing on SAR coordination and human resources to make recommendation and suggestion in order to minimize the loss of lives to future marine incidents. As a result, KCG shall augment its capabilities, inter alia, fast libeboats and rescue helicopters for prompt response to marine incidents at the coastal waters, and KCG shall re-adjust the establishment of Rescue Coordination Center to improve operational problems of current system in accordance with IMO guidance, KCG is required to introduce mandatory training, qualification and certificate system to enhance the professionalism of SAR personnel.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.9
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• pp.1808-1815
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• 2016

Stable operation of the dam and the river is directly related to the life and property of citizens, and hydrological observation data reliability is essential to the safety against disaster. Even though real-time data acquisition with high accuracy is needed for scientific and reliable water resources management, currently operating water gauges installed on the upper and down stream of dams or rivers are not easy to be calibrated or corrected on site to ensure higher reliability. K-water Institute has been operating an international accredited calibration laboratory for flows meters, rainfall and water gauges. Rainfall gauges are calibrated in the fixed standard room or on-site. However, due to the absence of on-site calibration procedure and system, on-site calibration for the water gauges are performed by an external agency. Therefore, a development of standard calibration procedure and system for on-site calibration of water gauges is needed to improve the reliability of observed hydrological data.

• Journal of the Korean Society of Marine Environment & Safety
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• v.15 no.4
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• pp.385-392
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• 2009

Maritime safety management needs active public participations because the sea is too wide for a government to respond to all unexpected accidents with limited resources. Marine rescue volunteer organizations of US, UK, Japan and Korea were compared one another on the base of disaster management governance theory, and recommendations for the development of marine rescue volunteer organization of Korea were proposed. The advanced organizations commonly have tradition of marine rescue voluntaryism in the advanced maritime countries. They have nation-wide networks and self-governing structures. Their main activities include public maritime safety education and fundraising programs as well as marine rescue operations. They have cooperative relationships with government agencies in charge of national maritime safety management, which are usually guaranteed by legislations or institutional systems. Donations from the public are major source of their finances. Members mainly consist of civil volunteers, and get basic compensations for their expenses. For the advancement of marine rescue volunteer organization of Korea, efforts are needed to strengthen the membership of civil rescue fleet, to activate public education and fundraising programs, and to amend the related law for institutional support.

• Journal of KIBIM
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• v.6 no.2
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• pp.39-46
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• 2016

While institutional matters such as improvement on Basic Guidelines for Construction Safety are greatly concerned to reduce falling accidents at construction sites, there are short of studies on how to practically predict accident signs at construction sites and to preemptively prevent them. As one of existing accident prevention methods, it was attempted to build the early warning system based on standardized accident scenarios to control the situations. However, the investment cost was too high depending on the site situation, and it did not help construction workers directly since it was developed to mainly provide support operational work support to safety managers. In the long run, it would be possible to develop the augmented reality based accident prevention method from the worker perspective by extracting product information from BIM, visually rendering it along with site installation materials term and comparing it with the site situation. However, to make this method effective, the BIM model should be implemented first and the technology that can promptly process site situations should be introduced. Accordingly, it is necessary to identify risk signs through lightweight image processing to promptly respond only with currently available resources. In this study, it was intended to propose the system concept that identified potential risk factors of falling accidents by histogram equalization, which was known as the fastest image processing method presently, used visual words, which could enhance model classification by wording image records, to determine the risk factors and notified them to the work manager.

• Journal of Korean Society of societal Security
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• v.1 no.2
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• pp.53-59
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• 2008

The lack of water resources is becoming a serious issue throughout the world. The water shortage in Korea is expected to increase. Groundwater can be a solution to this matter in some places. Especially, bank filtrations are known to be advantageous over conventional reserviors, even if they have some drawbacks such as their limited location for development and small sizes. The AHP(Analytic Hierarchy Process) is an analytical tool, supported by simple mathematics, which enables one to explicitly rank tangible and intangible factors against each other for the purpose of resolving conflicts or setting priorities. In order to check the applicability of AHP to the evaluation of bank filtration sites, four candidate locations were chosen. They have suffered from problems like water-supply shortage and delayed dam construction. The analysis results are compared with those of the previous study using a conventional method. It is believed that the developed method can a basis for reasonable decision-making regarding bank filtration development.

• Fire Science and Engineering
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• v.27 no.6
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• pp.83-88
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• 2013

Catastrophic disasters are sprouting out recently, i.e., the radiation leaks and the hydrofluoric acid gas leaks, etc. The restoration work for these kinds of disasters is very harmful and dangerous for human beings to handle themselves, thus allowing manless robots to fly the reconnaissance planes over to the disaster stricken areas and do the necessary work instead. For this endeavor and purpose, we created and tested an intelligent robot that can inspect those areas, using Mbed (ARM processor) technology temperature sensors and gas sensors aided by CAM (Computer-Aided Manufacturing) cameras. Also, HTTP Server, PC, androids and their combined efforts allow their remote controlled operation from far away with timing control. These intelligent robots can be on duty for 24 hours, minimizing the accidents and crimes and what not, and can respond more quickly when these misfortunes actually happen. We can anticipate the economic effects as well, derived from the reduced needs for hiring human resources.

• Journal of Satellite, Information and Communications
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• v.6 no.1
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• pp.75-79
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• 2011

Wireless devices can communicate between each other without existing infrastructure in mobile Ad-hod network. Ad hoc networks can be used under difficult conditions, where it is difficult to construct infrastructures, such as shadowing areas, disaster areas, war area, and so on. In order to support to considerable and various wireless services, more spectrum resources are needed. However, efficient utilization of the frequency resource is difficult because of spectrum scarcity and the conventional frequency regulation. Ad-hoc networks employing cognitive radio (CR) system that guarantee high spectrum utilization provide effective way to increase the network capacity. In this paper, we simulate and compare the performance of conventional single and cooperative spectrum sensing with CR system using ad-hoc networks in additive white Gaussian noise (AWGN) and Rayleigh channel model. And we demonstrate performance improvement by analyzing the system performance.