• Title/Summary/Keyword: Catastrophic disaster

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Numerical Study on Skin Burn Injury due to Flash Flame Exposure (돌발화염으로 인한 화상예측에 관한 수치해석적 연구)

  • Lee, Jun-Kyoung;Bang, Chang-Hoon
    • Fire Science and Engineering
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    • v.26 no.5
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    • pp.13-20
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    • 2012
  • Many fire-fighters suffer from the burn injuries, and the severe burns are the most catastrophic injury a person can survive, resulting in pain, emotional stress, and tremendous economic costs. It is important to understand the physiology of burns for prevention from skin burns and a successful treatment of a burn patient. But a few researches have been presented because the complex physical phenomena of our inside body like non-linearity characteristics of human skin make them difficult. Thus in this study, thermal analyses of biological tissues exposed to a flash fire causing severe tissue damage were studied by using a finite difference method based on the Pennes bio-heat equation. The several previous models for skin thermo-physical properties were summarized, and the calculated values with those models of tissue injury were compared with the results obtained by the previous experiment for low heat flux conditions. The skin models with good agreement could be found. Also, the skin burn injury prediction results with the best model for high heat flux conditions by flash flame were suggested.

A Study of Smart Robot Architecture and Movement for Observation of Dangerous Region (위험지역 감시스마트로봇의 설계와 동작에 관한 연구)

  • Koo, Kyung-Wan;Baek, Dong-Hyun
    • 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.

Comparison of Allowable Axial Stress Provisions of Cylindrical Liquid Storage Tanks under Seismic Excitation (지진 하중을 받는 원통형 플랜트 탱크 구조물의 축방향 허용압축응력 설계기준 비교 연구)

  • Oh, Chang Kook;Lee, So Ri;Park, Jang Ho;Bae, Doobyong
    • Journal of Korean Society of Steel Construction
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    • v.28 no.4
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    • pp.293-301
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    • 2016
  • Stability of cylindrical liquid storage tanks under seismic excitation could prevent catastrophic disaster of human life and economic loss. Domestic provisions on allowable compressive stress in tank walls to prohibit buckling failure are either incomplete or inconsistent, so foreign specifications such as API 650, BS EN 1998-4:2006 or New Zealand Standards are employed in stability design. In this study, response spectrum analyses are performed for plant tanks having different ratios of height to diameter or diameter to thickness to calculate hydrodynamic pressure on tank walls. Then nonlinear buckling analyses are conducted to estimate magnitude of buckling stress. By comparing analysis results with those from foreign design specifications, appropriate domestic design provisions are suggested.

Aerostatic instability mode analysis of three-tower suspension bridges via strain energy and dynamic characteristics

  • Zhang, Wen-ming;Qian, Kai-rui;Wang, Li;Ge, Yao-jun
    • Wind and Structures
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    • v.29 no.3
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    • pp.163-175
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    • 2019
  • Multispan suspension bridges make a good alternative to single-span ones if the crossed strait or river width exceeds 2-3 km. However, multispan three-tower suspension bridges are found to be very sensitive to the wind load due to the lack of effective longitudinal constraint at their central tower. Moreover, at certain critical wind speed values, the aerostatic instability with sharply deteriorating dynamic characteristics may occur with catastrophic consequences. An attempt of an in-depth study on the aerostatic stability mode and damage mechanism of three-tower suspension bridges is made in this paper based on the assessment of strain energy and dynamic characteristics of three particular three-tower suspension bridges in China under different wind speeds and their further integration into the aerostatic stability analysis. The results obtained on the three bridges under study strongly suggest that their aerostatic instability mode is controlled by the coupled action of the anti-symmetric torsion and vertical bending of the two main-spans' deck, together with the longitudinal bending of the towers, which can be regarded as the first-order torsion vibration mode coupled with the first-order vertical bending vibration mode. The growth rates of the torsional and vertical bending strain energy of the deck after the aerostatic instability are higher than those of the lateral bending. The bending and torsion frequencies decrease rapidly when the wind speed approaches the critical value, while the frequencies of the anti-symmetric vibration modes drop more sharply than those of the symmetric ones. The obtained dependences between the critical wind speed, strain energy, and dynamic characteristics of the bridge components under the aerostatic instability modes are considered instrumental in strength and integrity calculation of three-tower suspension bridges.

The July 2, 2017, Lantian landslide in Leibo, China: mechanisms and mitigation measures

  • He, Kun;Ma, Guotao;Hu, Xiewen;Liu, Bo;Han, Mei
    • Geomechanics and Engineering
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    • v.28 no.3
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    • pp.283-298
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    • 2022
  • Landslides triggered by the combination of heavy precipitation and anthropological disturbance in hilly areas cause severe damage to human lives, properties, and infrastructure constructions. A comprehensive investigation of the influencing factors and failure mechanisms of landslides are significant for disaster mitigation and prevention. This paper utilized the combination of detailed geological investigation, physical experimental testing as well as numerical modelling to determine the failure mechanism, and proposed a countermeasures of the Lantian landslide occurred on 2, July 2017. The results reveal that the Lantian landslide is a catastrophic reactivated slide which occurred in an active tectonic region in Southwest China. Because of the unique geological settings, the fully to highly weathered basalts in the study area with well-developed fractures favored the rainwater infiltration, which is the beneficial to slide reactivation. Engineering excavation and heavy precipitation are the main triggering factors to activate the slide motion. Two failure stages have been identified in the landslide. The first phase involves a shallow mass collapse originated at the upper slopes, which extends from the road to platform at rear part, which is triggered by excavation in the landslide region. Subjected to the following prolonged rainfall from 19 June to 2 July, 2017, the pore water pressure of the slope continually increased, and the groundwater table successively rise, resulting in a significant decrease of soil strength which leads to successive large-scale deep slide. Thereinto, the shallow collapse played a significant role in the formation of the deep slide. Based on the formation mechanisms of the landslide, detailed engineering mitigation measures, involving slope cutting, anchor cable frame, shotcrete and anchorage, retaining wall and intercepting ditch were suggested to reduce the future failure risk of the landslide.

Pathos of Color Green Expressed in Korean War Films (전쟁영화에서 초록의 색채표현과 파토스)

  • Jong-Guk Kim
    • Journal of Information Technology Applications and Management
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    • v.29 no.6
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    • pp.123-134
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    • 2022
  • War films are a general term for films that have battlefields as their main background. Although war films as a genre directly deal with combat situations, they also deal with characters or subjects related to war. War films promote patriotism and nationalism, but they also argue against war by highlighting the disastrous war. This study is based on the color theory that the meaning of film color is temporarily and infinitely generated according to the cultural differences, with Eisenstein's creative theory on film color and pathos. I wanted to clarify the pathos effect and the meaning of color green expressed in the Korean war films. In war films, colors are visualized in art forms such as symbols, similes and metaphors. In war films, color green symbolizes life. On the battlefield, the green of nature stands against the catastrophic situation. The green of ecology, which insists on the flow of life, evokes fear in ecological crises such as war, disaster and climate change. The dark green caused by a catastrophe like war warns of the destruction of life. The connotation of color is temporarily and infinitely expands according to the cultural differences. The dark green, which visualizes the battlefield of destruction, is a form and element of pathos that indicates changes in emotions such as sadness, pity, grief and despair. Pathos as an emotional appeal is a leap from the quality to the quality of the means of expression and refers to the departure from Dasein. The green color that dominates the visuals of war films is a symbol of life and functions as a pathos that makes emotional changes take a new leap. A qualitative leap through pathos means all changes that become new.

A Study on Strengthening Consequence Management System Against CBRN Threats (CBRN 위협에 대비한 사후관리체계 강화방안)

  • Kwon, Hyuckshin;Kwak, Minsu;Kim, Kwanheon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.40 no.4
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    • pp.429-435
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    • 2020
  • North Korea declared itself complete with nuclear force after its sixth nuclear test in 2017. Despite efforts at home and abroad to denuclearize the Korean Peninsula, the prospects for the denuclearization are not bright. Along with political and diplomatic efforts to deter NK's WMD threats, the government is required to strengthen its consequence management capabilities against 'catastrophic situations' expected in case of emergency. Accordingly, this study was conducted to present measures to strengthen follow-up management against CBRN threats. The research model was partially supplemented and utilized by the THIRA process adopted and utilized by the U.S. Department of Homeland Security among national-level disaster management plan development models. Korea's consequence management (CM) system encompasses risk and crisis management on disaster condition. The system has been carried out in the form of a civil, government and military integrated defense operations for the purpose of curbing the spread or use of CBRNs, responding to threats, and minimizing expected damages. The preventive stage call for the incorporation of CBRN concept and CM procedures into the national management system, supplementing the integrated alarm systems, preparation of evacuation facilities, and establishment of the integrated training systems. In the preparation phase, readjustment of relevant laws and manuals, maintenance of government organizations, developing performance procedures, establishing the on-site support systems, and regular training are essential. In the response phase, normal operations of the medical support system for first aid and relief, installation and operation of facilities for decontamination, and development of regional damage assessment and control guidelines are important. In the recovery phase, development of stabilization evaluation criteria and procedures, securing and operation of resources needed for damage recovery, and strengthening of regional damage recovery capabilities linked to local defense forces, reserve forces and civil defense committees are required.

Data-driven event detection method for efficient management and recovery of water distribution system man-made disasters (상수도관망 재난관리 및 복구를 위한 데이터기반 이상탐지 방법론 개발)

  • Jung, Donghwi;Ahn, Jaehyun
    • Journal of Korea Water Resources Association
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    • v.51 no.8
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    • pp.703-711
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    • 2018
  • Water distribution system (WDS) pipe bursts are caused from excessive pressure, pipe aging, and ground shift from temperature change and earthquake. Prompt detection of and response to the failure event help prevent large-scale service interruption and catastrophic sinkhole generation. To that end, this study proposes a improved Western Electric Company (WECO) method to improve the detection effectiveness and efficiency of the original WECO method. The original WECO method is an univariate Statistical Process Control (SPC) technique used for identifying any non-random patterns in system output data. The improved WECO method multiples a threshold modifier (w) to each threshold of WECO sub-rules in order to control the sensitivity of anomaly detection in a water distribution network of interest. The Austin network was used to demonstrated the proposed method in which normal random and abnormal pipe flow data were generated. The best w value was identified from a sensitivity analysis, and the impact of measurement frequency (dt = 5, 10, 15 min etc.) was also investigated. The proposed method was compared to the original WECO method with respect to detection probability, false alarm rate, and averaged detection time. Finally, this study provides a set of guidelines on the use of the WECO method for real-life WDS pipe burst detection.

Prediction of Temperature and Heat Wave Occurrence for Summer Season Using Machine Learning (기계학습을 활용한 하절기 기온 및 폭염발생여부 예측)

  • Kim, Young In;Kim, DongHyun;Lee, Seung Oh
    • Journal of Korean Society of Disaster and Security
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    • v.13 no.2
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    • pp.27-38
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    • 2020
  • Climate variations have become worse and diversified recently, which caused catastrophic disasters for our communities and ecosystem including economic property damages in Korea. Heat wave of summer season is one of causes for such damages of which outbreak tends to increase recently. Related short-term forecasting information has been provided by the Korea Meteorological Administration based on results from numerical forecasting model. As the study area, the ◯◯ province was selected because of the highest mortality rate in Korea for the past 15 years (1998~2012). When comparing the forecasted temperatures with field measurements, it showed RMSE of 1.57℃ and RMSE of 1.96℃ was calculated when only comparing the data corresponding to the observed value of 33℃ or higher. The forecasting process would take at least about 3~4 hours to provide the 4 hours advanced forecasting information. Therefore, this study proposes a methodology for temperature prediction using LSTM considering the short prediction time and the adequate accuracy. As a result of 4 hour temperature prediction using this approach, RMSE of 1.71℃ was occurred. When comparing only the observed value of 33℃ or higher, RMSE of 1.39℃ was obtained. Even the numerical prediction model of the whole range of errors is relatively smaller, but the accuracy of prediction of the machine learning model is higher for above 33℃. In addition, it took an average of 9 minutes and 26 seconds to provide temperature information using this approach. It would be necessary to study for wider spatial range or different province with proper data set in near future.

Estimation of Economic Impacts of SARS Disaster to Tour Demands of Four Major Countries in Korea

  • Kim, Geun-Young;Moore II, James E.;Chae, Seon-Hee
    • Journal of the Korean Society of Hazard Mitigation
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    • v.9 no.6
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    • pp.77-87
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    • 2009
  • Potential risks of communicable disease outbreaks have significantly increased in the era of global society. However, contingency planning of local governments for communicable diseases is not prepared to the proper level in various governmental sectors of many countries. Human being has been remarkable advances in medical science and public health. However, Severe Acute Respiratory Syndrome (SARS) still remains as a very dangerous transmissible disease that has great potential to create catastrophic consequences of casualties. The SARS outbreak between November 2002 and July 2003 resulted in 8,096 known infected cases and 774 deaths with a mortality rate of 9.6% worldwide (WHO, 2004). It is regarded as one of the human health disasters. Since about sixty-six percent of total SARS cases in the world were reported in People's Republic of China, Korean tour industry was significantly affected as a neighboring country. The objective of this research is to investigate major factors of Korea entry data sets, and to analyze economic impacts of Korean tour business interruption due to the period of SARS outbreak with tourist cases of four countries: Japan, U.S.A., China, and Taiwan. Results from this research show the seasonal and long-term trends of entry data sets of four countries, and direct and indirect impacts of SARS to Korean tour industry.