• Nuclear Engineering and Technology
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• v.53 no.3
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• pp.967-973
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• 2021

In 2011, an earthquake and subsequent tsunami hit the Fukushima Daiichi Nuclear Power Plant, causing simultaneous accidents in several reactors. This accident shows us that if there are several reactors on site, the seismic risk to multiple units is important to consider, in addition to that to single units in isolation. When a seismic event occurs, a seismic-failure correlation exists between the nuclear power plant's structures, systems, and components (SSCs) due to their seismic-response and seismic-capacity correlations. Therefore, it is necessary to evaluate the multi-unit seismic risk by considering the SSCs' seismic-failure-correlation effect. In this study, a methodology is proposed to obtain the seismic-response-correlation coefficient between SSCs to calculate the risk to multi-unit facilities. This coefficient is calculated from a probabilistic multi-unit seismic-response analysis. The seismic-response and seismic-failure-correlation coefficients of the emergency diesel generators installed within the units are successfully derived via the proposed method. In addition, the distribution of the seismic-response-correlation coefficient was observed as a function of the distance between SSCs of various dynamic characteristics. It is demonstrated that the proposed methodology can reasonably derive the seismic-response-correlation coefficient between SSCs, which is the input data for multi-unit seismic probabilistic safety assessment.

• Journal of Appropriate Technology
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• v.5 no.1
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• pp.33-37
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• 2019

One of main problems in developing electricity grid for archipelago country like Indonesia is the geographical concerns as it consists of many islands. In some rural areas, electricity has not been available yet due to the limited infrastructure access, leading to high investment cost. In this study, a portable energy storage system based on the lithium-ion batteries called Tabung Listrik or TaLis (DC-based power bank) and DC house system were proposed as the solution for providing electricity for rural areas with relatively lower cost. TaLis is designed to be portable so it is easy to carry around as well as it can be used for many purposes. Since 2017, TaLis prototype has been used as the energy storage in a DC house system at Sekolah Master Indonesia, where an array of PV rooftop is functioned as the main DC power supply. Besides, some TaLis were also dispatched for emergency response during the disaster situations in Indonesia, such as during the measles outbreak in Asmat-Papua, the earthquake disaster in Lombok and tsunami in Palu.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.6
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• pp.93-100
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• 2008

Dense of population construction and high density of skyscraper, and geological characteristics caused natural disasters(e.g. typhoon, tsunami, flood, storm, earthquake, etc.) and manmade disasters(e.g. fire, collapse, explosion, traffic accident, etc.). the extent and scale of the disaster are getting larger. To cope with such problems, Busan City has established the basic plan to secure the life and property of the citizens through model strategy and design of Ubiquitous-Safety Busan. This study quantitatively analyzed the ripple effect on local economy through the fulfillment of Ubiquitous-Safety. The production inducing effect of 250 billion won directly and indirectly can be estimated due to the realization of Ubiquitous-Safety. The value added effect of 115 billion won can be estimated. the employment effect of 5,580 persons can be generated with income effect of 51 billion won.

• Nuclear Engineering and Technology
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• v.44 no.3
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• pp.225-236
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• 2012

The Fukushima-Daiichi accident shook the world, as a well-known plant design, the General Electric BWR Mark I, was heavily damaged in the tsunami, which followed the Great Japanese Earthquake of 11 March 2011. Plant safety functions were lost and, as both AC and DC failed, manoeuvrability of the plants at the site virtually came to a full stop. The traditional system of Emergency Operating Procedures (EOPs) and Severe Accident Management Guidelines (SAMG) failed to protect core and containment, and severe core damage resulted, followed by devastating hydrogen explosions and, finally, considerable radioactive releases. The root cause may not only have been that the design against tsunamis was incorrect, but that the defence against accidents in most power plants is based on traditional assumptions, such as Large Break LOCA as the limiting event, whereas there is no engineered design against severe accidents in most plants. Accidents beyond the licensed design basis have hardly been considered in the various designs, and if they were included, they often were not classified for their safety role, as most system safety classifications considered only design basis accidents. It is, hence, time to again consider the Design Basis Accident, and ask ourselves whether the time has not come to consider engineered safety functions to mitigate core damage accidents. Associated is a proper classification of those systems that do the job. Also associated are safety criteria, which so far are only related to 'public health and safety'; in reality, nuclear accidents cause few casualties, but create immense economical and societal effects-for which there are no criteria to be met. Severe accidents create an environment far surpassing the imagination of those who developed EOPs and SAMG, most of which was developed after Three Mile Island - an accident where all was still in place, except the insight in the event was lost. It requires fundamental changes in our present safety approach and safety thinking and, hence, also in our EOPs and SAMG, in order to prevent future 'Fukushimas'.

• The Journal of the Korea Contents Association
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• v.17 no.4
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• pp.267-274
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• 2017

The natural disasters such as typhoon, earthquake, flood, heavy rain, drought, sweltering heat, wind wave, tsunami and so on, are difficult to estimate the scale of damage and spot. Also, these disasters were being damaged to human life. However, if based on the disaster statistics the past damage cases are analyzed and the estimated damages can be calculated, the initial damage action can be taken immediately and based on the estimated damage scale the damage can be mitigated. In the present study, therefore, we proposed the functions of wind wave damage estimation for the southern coast. The functions are developed based on Disaster Report('91~'14) for wind wave and typhoon disaster statistics, regional characteristics and observed sea weather.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.80-83
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• 2007

Entering 21st century, various natural disasters have been caused by the scorching heat wave, earthquake, tsunami, typhoon and so on. The casuality and damages have been drastically increased in terms of the frequency and magnitude. Therefore, 50 nations around the world agreed to build up the GEO(Global Earth Observation) in charge of the earth observation for the understanding of the earth system changes, monitoring and prediction and it is on operation. To keep the pace with GEOSS for the cooperation of Science & Technology and to successfully achieve the GEOSS project, KGEO office was established and has been on its duty. Moreover, for more prosperous building of the GEOSS, in cooperation with KGEO and KISTI(Korea Institute of Science and Technology Information), we've conducted the survey of the domestic situation about 9 societal benefit areas of the GEOSS. This survey consists of 5 sections as follows: the standardization, the information system management, the raw data and metadata, the infrastructure, and the others. This survey results will be used as the basic material for establishing the National Global Earth Observation System.

• Journal of the Korea Society of Computer and Information
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• v.18 no.7
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• pp.93-100
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• 2013

The ensuing disaster brought by the massive earthquake and tsunami in the northeastern region of Japan in 2011 placed Japan, one of the three most advanced economic powers in the world, in a defenseless state. With the rising interest in disaster recovery, Korea is also making efforts to provide technological support for barrier-free system operation 24 hours a day, 365 days a year. To protect intelligence assets efficiently, this study draws a job performance plan to prepare for disasters, which systemizes methodical coping capabilities into business plans when disasters occur. Moreover, this study systemizes the job performance plan to allow members easy access to information that will help them proceed without confusion in emergencies. This plant is intended to protect intelligence assets of an organization clearly and promptly.

• Journal of Navigation and Port Research
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• v.33 no.10
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• pp.699-702
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• 2009

Currently many vessels determine an overhead obstruction by a rule of thumb based on their draft for maritime navigation. Therefore they doesn't have a good overhead obstruction clearance because vertical position of vessels varies on time by tidal. As a result, it is occurred maritime accidents that the mainmast of vessels is bumped against overhead facilities. And disaster by global warming and rising sea levels have increased casualties. So we feel keenly the necessity of warning system for not an earthquake but disaster wave such a tsunami. This paper analyzes a precise GPS ephemeris for maritime precise positioning to solve these problems. The precise GPS ephemeris provided by International GNSS service gives a difficulty to real-time application because of its sample interval. This paper proposes an effective interpolation method for real-time application, and it analyzes an accuracy of precise GPS ephemeris through an interpolation method.

• Nuclear Engineering and Technology
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• v.47 no.1
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• pp.11-25
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• 2015

The accident at Japan's Fukushima Daiichi nuclear power plant in March 2011, caused by an earthquake and a subsequent tsunami, resulted in a failure of the power systems that are needed to cool the reactors at the plant. The accident progression in the absence of heat removal systems caused Units 1-3 to undergo fuel melting. Containment pressurization and hydrogen explosions ultimately resulted in the escape of radioactivity from reactor containments into the atmosphere and ocean. Problems in containment venting operation, leakage from primary containment boundary to the reactor building, improper functioning of standby gas treatment system (SGTS), unmitigated hydrogen accumulation in the reactor building were identified as some of the reasons those added-up in the severity of the accident. The Fukushima accident not only initiated worldwide demand for installation of adequate control and mitigation measures to minimize the potential source term to the environment but also advocated assessment of the existing mitigation systems performance behavior under a wide range of postulated accident scenarios. The uncertainty in estimating the released fraction of the radionuclides due to the Fukushima accident also underlined the need for comprehensive understanding of fission product behavior as a function of the thermal hydraulic conditions and the type of gaseous, aqueous, and solid materials available for interaction, e.g., gas components, decontamination paint, aerosols, and water pools. In the light of the Fukushima accident, additional experimental needs identified for hydrogen and fission product issues need to be investigated in an integrated and optimized way. Additionally, as more and more passive safety systems, such as passive autocatalytic recombiners and filtered containment venting systems are being retrofitted in current reactors and also planned for future reactors, identified hydrogen and fission product issues will need to be coupled with the operation of passive safety systems in phenomena oriented and coupled effects experiments. In the present paper, potential hydrogen and fission product issues raised by the Fukushima accident are discussed. The discussion focuses on hydrogen and fission product behavior inside nuclear power plant containments under severe accident conditions. The relevant experimental investigations conducted in the technical scale containment THAI (thermal hydraulics, hydrogen, aerosols, and iodine) test facility (9.2 m high, 3.2 m in diameter, and $60m^3$ volume) are discussed in the light of the Fukushima accident.

• Journal of KIISE:Information Networking
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• v.37 no.5
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• pp.351-362
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• 2010

In Korea, national information infrastructure has been grown well because of the rapid growth and supply of Internet, but threats of cyber terror and cyber war are also increasing. Cyber attacks on knowledge information society threaten industry, economy and security. Major countries realize that cyber attacks can cause national heavy loss. So, they are trying to adopt policy on their cyber safe. And natural environmental crisises are increasing around the world. Countries such as India and Philippine in which tsunami, typhoon and earthquake are often occurring have national systematic disaster management system that can prevent and recover. We need systematic management for prevention and recovery from cyber terror, and need to establish national cyber disaster management system. Therefore, in this paper, we analyze major countries's cyber security policy and suggest a method of establishing the national cyber disaster management system.