• Journal of the Korean Society of Safety
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• v.39 no.2
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• pp.65-74
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• 2024

We analyzed the relationship between the normal measurement of the seismic accelerometer (SA) and the error rate of the output voltage linear ratio to propose an evaluation method to determine whether the SA in use is measuring normally. Utilizing a test bed, the regular operation of SA in use was evaluated using acceleration data measured through impact tests since there are no regulations regarding performance testing of SA in use. For the used SA, the error rate of the output voltage linear ratio, which is a major performance criterion, was evaluated. We analyzed common characteristics of the SA that satisfied the impact test and the performance criteria of the output voltage linear ratio error rate. The results indicated that we must consider the decreasing trend and convergence of the error rate as the measurement angle increases, ensuring that the average value of the output voltage linear ratio error rate is within 1%.

• Journal of Korean Society of Disaster and Security
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• v.9 no.2
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• pp.87-91
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• 2016

In recent years, lots of damages appear frequently due to cyber terrorism and natural disasters such as typhoon 'Chaba', earthquake at Kyeongju. The damages lead to people's anxiety and public institutions connected directly with them also can't be free from the threat situation. In addition, public institutions must prepare business continuity issues with the highest priority in the event of disasters because they are closest with people's safety. However, preceding researches suggest needs of disaster mitigation activities management system or central office oriented top-down BCP establishing system. In this study, We grasp the current status of public institutions's business continuity plan(BCP) against disaster and we propose an efficient bottom-up method for structuring the BCP of public institutions.

• Journal of the Korean Society of Hazard Mitigation
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• v.1 no.1 s.1
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• pp.139-155
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• 2001

We investigate the vertical velocity models beneath the newly installed broadband seismic network of KMA (Korea Meteorological Administration) by using receiver function inversion technique. The seismic phases are primarily P-to-S conversions and reverberations generated at the two highest impedance interfaces like the Moho (crust-mantle boundary) and the sediment-basement contact. We obtained the teleseismic P-wave receiver functions, which were derived from teleseismic records of Seoul (SEO), Inchon (INCN), Tejeon (TEJ) , Sosan (SOS/SES), Kangnung (KAN), Ulchin (ULC/ULJ), Taegu (TAG), Pusan (PUS), and Ullung-do (ULL) stations. For Kwangju (KWA/KWJ) and Chunchon (CHU) stations, the Moho conversion Ps arrivals and waveforms of radial receiver functions are azimuthally inconsistent and unclear. From the receiver function inversion result, we found that crustal thickness is 29 km at INCN, SEO, and SOS (SES) stations, 28 km at KAN station in the Kyonggi Massif, 32 km at TEJ station in Okchon Folded Belt, 34 km at TAG, 33 km at PUS station in the Kyongsang Basin, 32 km at KWJ station (readjusted station by prior KWA station) included in the Youngdong-Kwangju Depression Zone, 28 km at ULC station in the eastern margin of the Ryongnam Massif, and 17 km at ULL station in the Ullung Island of the East Sea, respectively. The Moho configuration of INCN, SOS, KWJ, and KAN stations show a laminated smooth transition zone with a 3-5 km thick. The upper crusts(${\sim}5km$) of KAN, ULC, and PUS stations show complex structures with a high velocity. The unusually thick crusts are found at the TAG and PUS stations in the Kyongsang Basin compared to the thin (29-32 km) crust of the western part (INCN, SEO, SOS, TEJ, and KWA stations) The crustal thickness beneath Ullung Island (ULL station) shows the suboceanic crust with about 17 km thickness and complex with a high velocity layer of the upper crust, and the amplitudes of Incoming Ps waves from the western direction are relatively large compared to those from othor directions.

• Journal of the Korean GEO-environmental Society
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• v.12 no.1
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• pp.81-87
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• 2011

The characteristics of vertical to horizontal ratio of response spectrum from 20 recent earthquakes were analysed. Response spectrum of 260 horizontal and 130 vertical ground motions were normalized by peak ground acceleration at each resonance frequency from 0.1 to 50Hz. It has been identified that the ratio of vertical to horizontal response spectrum has strong dependancy on epicentral distance and resonance frequency. The ratio of vertical to horizontal response spectrum for the 0-50km epicentral distance group are larger than 2/3 values, which is a standard engineering rule-of-thumb V/H=2/3, at resonance frequency above 7-8Hz. All the 3 groups such as 50-100, 100-150- and 150-200km epicentral distance have shown larger values of vertical to horizontal ratio than 2/3 at resonance frequency above 15Hz and also are larger than 2/3 at resonance frequency below 8-10Hz. Even though there are differences in specific resonance frequency values which depend on the epicentral distance group, we should be careful of seismic design of vertical component of the structures winch are located within the range of about 200km distance. form the potentially seismic causative faults.

• The Journal of the Korea Contents Association
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• v.9 no.5
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• pp.241-248
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• 2009

On 7 December 2007, the Hong Kong registered tanker Hebei Spirit, laden with 209,000 tonnes of crude oil, was struck by the crane barge Samsung No 1, whilst at anchor about five miles off Taean on the West Coast in Korea. About 10,500 tonnes of crude oil escaped into the sea from the Hebei Spirit. The recent oil leakage from a tanker in seas off Taean has turned the sea farms and fishing areas on the country's western coast into a sea of oil. Analysts say the spill is considered as one of the world's devastating sea pollution cases involving oil. In our contemporary society where people are exposed to potential dangers in every aspect, no one can be free from such dangers. With an increase in human casualties due to disaster, disaster reporting plays a vital role in preventing and minimizing damages. Despite such enormous significance, however, Korean disaster reporting has not performed effectively. In this contexts, this study analyzed the problems of disaster reporting in Korea, with the case of Hebei Spirit oil Spill in Taean-gun. And, this study suggest the establish ways and means needed to improve the disaster reporting in Korea with the case of Hebei Spirit case.

• The KIPS Transactions:PartD
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• v.13D no.6 s.109
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• pp.775-788
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• 2006

Many disaster monitoring systems are constantly studied to prevent disasters such as environmental pollution, the breaking of a tunnel and a building, flooding, storm earthquake according to the progress of wireless telecommunication, the miniaturization of terminal devices, and the spread of sensor network. A disaster monitoring system can extract information of a remote place, process sensor data with rules to recognize disaster situation, and provide work for preventing disaster. However existing monitoring systems are not enough to predict and prevent disaster, because they can only process current sensor data through utilizing simple aggregation function and operators. In this paper, we design and implement a disaster prevention system to predict near future dangerous area through using outside sensor network and spatial Information. The provided prediction technique considers the change of spatial information over time with current sensor data, and indicates the place that could be dangerous in near future. The system can recognize which place would be dangerous and prepare the disaster prevention. Therefore, damage of disaster and cost of recovery would be reduced. The provided disaster prevention system and prediction technique could be applied to various disaster prevention systems and be utilized for preventing disaster and reducing damages.

• Journal of Korean Society of Disaster and Security
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• v.16 no.2
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• pp.75-83
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• 2023

In general, bridges are facilities installed for the purpose of easily passing through sections such as valleys and rivers. Railway bridges that run through downtown areas are damaged due to external factors such as earthquakes and collisions with passing vehicles, resulting in serious human casualties. This can cause serious human and properties damage, such as functional paralysis in downtown areas. Depending on the degree of damage, repair work such as partial repair or full replacement is in progress for the bridge where the collision occurred. When damage or deformation occurs due to collision, the repair method is determined according to the degree of deformation and the degree to which the load capacity of the bridge is affected by the deformation. In this study, a numerical analysis review was performed on the repair work for the local deformation caused by the collision of a vehicle on an old railway bridge installed and in operation in an urban area. To this end, a structural safety review of the bridge for local deformations caused by vehicle collisions was conducted. In this paper, a repair method for the accident bridge was presented based on the analysis results.

• The Journal of the Korea Contents Association
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• v.17 no.11
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• pp.102-109
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• 2017

The Nation's Constitution stipulates that the nation should strive to prevent disasters and protect the public from harm. That is, the nation is a protector of the protection of people's lives and property from potential danger. The disasters are the most important global issues, and disasters scope are not confined to natural disasters such as pre-existing earthquakes, landslides, floods, fires and fires extend to cyber terror and disease. In the age of IoT and ability of analyze big data, the establishment of a disaster prevention service system in modern society is a priority for the nation. In this study, we will explore the disaster prevention services for each country using IoT technology. Based on the research, it is believed that it will be the foundation for establishing strategies for service system of disasters using IoT technology.

• Journal of Korean Society of societal Security
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• v.2 no.4
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• pp.35-41
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• 2009

If any bridge has the monitoring system, the bridge manager can check the history of bridge behavior and the progress of the damage more exactly. When the unexpected event (ex: earthquake and flood) happens, the manager can check the safety condition of the bridge and make the pertinent action for bridge management which is reduction of vehicle speed or traffic control through the system. Additionary the manager can make the well-timed repair or reinforcement through the system, so he can save the management cost or the life cycle cost. This study presents the method of setting the criteria by FEM analysis in bridge monitoring system, and the standard progress for setting the criteria about measurement items of monitoring system for the steel box type bridge.

• Fire Science and Engineering
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• v.32 no.5
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• pp.87-94
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• 2018

This study examined the role of volunteer fire fighters in coping with great disasters in terms of community-based disaster management to provide some implications from a qualitative comparative case study between Korea and Japan. Kobe, which suffered from the Great Hanshin-Awaji earthquake in 1995, was the study area. The city experienced an inadequate institutional system and lack of disaster management infrastructure at the time before the disaster. The study indicates that Korea volunteer fire fighters are not prepared sufficiently to tackle great disasters in terms of the supporting system, capacity and role by analyzing improvement plans of Japanese Volunteer Fire Fighters after Great East Japan earthquake in 2011. The results of the case study suggests improvements in the disaster management system to provide cooperation between the central government and local government, core task distribution, and community-based disaster management.