• Title/Summary/Keyword: Secondary disaster

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Experimental Study on Moisture Content According to Addition of Surfactants (계면활성제 첨가에 따른 함수율에 관한 실험적 연구)

  • Kim, Nam-Kyun;Rie, Dong-Ho
    • Fire Science and Engineering
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    • v.29 no.2
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    • pp.79-83
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    • 2015
  • The fire accident is a representative type of disaster that can largely impact on business. Therefore, precautionary measures and rapid initial response is very important when a disaster occurs. The storage of porous combustibles is inevitable in coal yard, plywood processing industry, and others that are currently operating. Initial fire fighting of fire and identifying the ignition point in such a porous combustible storage space are so difficult that if the initial response is failed, being led to deep-seated fire, surface fire is likely to result in secondary damage. In addition, deep-seated fire can cause personal injuries and property damage due to a large amount of toxic gases and reignition. Therefore damage reduction measures is required around the storage space to handle a porous flammable. Improving the penetration performance of the concentration of the surfactant is carried out as underlying study, which is about an deep-seated fire extinguishing efficiency augmentation when using wetting agents. The porous materials used in the experiments is radiata pine wood flour, which occupies more than 75% of the domestic wood market. Fire fighting water is selected as Butyl Di Glycol (BDG), which is being used for infiltration extinguishing agent, and the experiment was carried out by producing a standard solution. The experiment was carried out on the basis of the Deep-Seated Fire Test of NFPA 18. The amount of watering, porous material to the internal amount of penetration, and runoff measurement out of the porous material was conducted. According to experimental results, as the surface tension is reduced, the surfactant concentration macroscopic penetration rate decreases, but infiltration to a porous material is shown to have growth characteristics.

A Study on Indoor Environment Safety Level Certification of Educational Facilities and School Safety Level Evaluation (교육시설 안전 등급 인증과 학교 안전도 심사에 대한 연구)

  • Myoung-Kwan Kim;Young-Guk Kwon
    • Journal of the Korea Safety Management & Science
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    • v.25 no.2
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    • pp.17-28
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    • 2023
  • This study aimed to verify the validity of the evaluation items and weight determination of the indoor environmental safety area, which has the most frequent accidents, among the safety certification evaluations of educational facilities by the Ministry of Education of the Republic of Korea, which has been conducted since May 2021. As a preceding study, the evaluation items of the school safety evaluation checklist being implemented in the US state of Vermont were compared, and the causes of accidents judged by teachers in the accident experiences written by 200 Korean teachers were compared with the safety certification evaluation items belonged to the Ministry of Education. In addition, research literature using the AHP analysis technique on safety risks of elementary and secondary schools in China and safety evaluation index study cases of 539 elementary school children in Indonesia were analyzed. Through these preceding studies, measures to add and adjust evaluation items were derived and the validity and importance rankings of evaluation items were calculated through AHP questionnaires to teachers and safety experts. In addition, a survey was conducted on 104 ordinary people to verify the results of expert analysis. As a result of expert AHP analysis, 'safety education and disaster response training (.396)' was the highest priority for the relative importance of the first layer, followed by 'safety measures (.387)' and 'building materials'. Safety (.216)' was found to be the highest priority. In the overall importance ranking of the 13 second-tier screening items, safety accident prevention education had the highest priority and disaster preparedness training ranked second, proving that the Ministry of Education's review weight was underestimated. In addition, slip and collision accident countermeasures, which were not in the existing Ministry of Education review items, ranked 4th, laboratory practice room safety measures ranked 6th, and sanitation, cleanliness, hazardous substance management, and cafeteria/cooking room safety measures ranked 9th, indicating a significant level of importance. Referring to the importance ranking, which is the result of this study, it is suggested that it is necessary to review the weight of each review item again.

A Study on the Safety against Secondary Disaster due to Submergence of Electrical Equipments in Underground Premises using Fuzzy Theory (퍼지이론을 이용한 지하구내 전기설비의 침수에 의한 2차 재해에 대한 안전성 연구)

  • Kim, Joon-Bum;Cho, Seong-Won;Kim, Jae-Min;Jung, Jong-Wook;Lim, Young-Bae;Jung, Jin-Soo
    • Proceedings of the KIEE Conference
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    • 2006.07d
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    • pp.2079-2080
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    • 2006
  • 지하상가와 같은 지하구내에 설치된 전기설비는 침수피해의 가능성이 상존한다. 그러므로 침수상황에서 재난복구를 위해 투입되는 인력에게 미칠 수 있는 2차 재해에 대한 안전성을 평가하고, 생명과 재산의 피해를 최소화 할 수 있는 적절한 대책이 필요하다. 본 연구에서는 먼저 지하구내 침수사고사례 조사를 통해 사고의 패턴을 분류하고 전기적 위해요소를 도출한다. 그리고 그것을 바탕으로 퍼지추론을 적용해서 침수상황을 통제하고 안전성을 평가하는 알고리즘과 시스템을 제안한다.

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Ultra-low cycle fatigue tests of Class 1 H-shaped steel beams under cyclic pure bending

  • Zhao, Xianzhong;Tian, Yafeng;Jia, Liang-Jiu;Zhang, Tao
    • Steel and Composite Structures
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    • v.26 no.4
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    • pp.439-452
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    • 2018
  • This paper presents experimental and numerical study on buckling behaviors and hysteretic performance of Class 1 H-shaped steel beam subjected to cyclic pure bending within the scope of ultra-low cycle fatigue (ULCF). A loading device was designed to achieve the pure bending loading condition and 4 H-shaped specimens with a small width-to-thickness ratio were tested under 4 different loading histories. The emphasis of this work is on the impacts induced by local buckling and subsequent ductile fracture. The experimental and numerical results indicate that the specimen failure is mainly induced by elasto-plastic local buckling, and is closely correlated with the plastic straining history. Compared with monotonic loading, the elasto-plastic local buckling can occur at a much smaller displacement amplitude due to a number of preceding plastic reversals with relative small strain amplitudes, which is mainly correlated with decreasing tangent modulus of the material under cyclic straining. Ductile fracture is found to be a secondary factor leading to deterioration of the load-carrying capacity. In addition, a new ULCF life evaluation method is proposed for the specimens using the concept of energy decomposition, where the cumulative plastic energy is classified into two categories as isotropic hardening and kinematic hardening correlated. A linear correlation between the two energies is found and formulated, which compares well with the experimental results.

Rotational capacity of H-shaped steel beams under cyclic pure bending

  • Jia, Liang-Jiu;Tian, Yafeng;Zhao, Xianzhong;Tian, Siyuan
    • Steel and Composite Structures
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    • v.30 no.2
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    • pp.123-140
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    • 2019
  • This paper presents experimental study on effects of width-to-thickness ratio and loading history on cyclic rotational capacity of H-shaped steel beams subjected to pure bending. Eight Class 3 and 4 H-shaped beams with large width-to-thickness ratios were tested under four different loading histories. The coupling effect of local buckling and cracking on cyclic rotational capacity of the specimens was investigated. It was found that loss of the load-carrying capacity was mainly induced by local buckling, and ductile cracking was a secondary factor. The width-to-thickness ratio plays a dominant effect on the cyclic rotational capacity, and the loading history also plays an important role. The cyclic rotational capacity can decrease significantly due to premature elasto-plastic local buckling induced by a number of preceding plastic reversals with relative small strain amplitudes. This result is mainly correlated with the decreasing tangent modulus of the structural steel under cyclic plastic loading. In addition, a theoretical approach to evaluate the cyclic rotational capacity of H-shaped beams with different width-to-thickness ratios was also proposed, which compares well with the experimental results.

Digital Tourism Security System for Nepal

  • Shrestha, Deepanjal;Wenan, Tan;Khadka, Adesh;Jeong, Seung Ryul
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.11
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    • pp.4331-4354
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    • 2020
  • Nepal is a sensitive and disaster-prone country where safety and security risk are of high concern for travelers. Digital technologies can play a vital role in addressing safety and security issues in the country. This research work proposes a Digital tourism security system design for addressing the safety and security issues in tourism industry of Nepal. The study uses Design science research methodology to identify artifacts, interactions, information flow and dependencies between them which are then mapped with existing prevalent technology to provide design solutions. Data is obtained from interview of tourist and experts as a primary source and technical documents/draft, software documentations, surveys as secondary source. Generalized information model, Use cases model, Network architecture model, Layered taxonomy model and Digital tourism technology reference model are the outcomes of the study. The work is very important as it talks specifically about implementation and integration of digital technologies in tourism security governance at federal, provincial, municipal and rural level. The research supplements as a knowledge document for design and implementation of digital tourism security system in practice. As there is very less work on digital systems in tourism security of Nepal, this work is a pioneer and first of its kind.

The effectiveness of gamification on nursing practice for undergraduate students: A systematic review

  • Hyun Kyoung, Kim
    • International Journal of Advanced Culture Technology
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    • v.10 no.4
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    • pp.110-116
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    • 2022
  • The purpose of this study was to examine the effectiveness of gamification in nursing practice for undergraduate students, as well as to explore the use of gamification in nursing education. This study is a systematic review of RCTs evaluating the effectiveness of gamification in nursing practice for undergraduate students. A total of 7 articles were identified in a search of PubMed, Cochrane Library, and Embase, and the additional databases were CINAHL (in English) and RISS (in Korean) between September 28, 2022 to October 5, 2022. Themes related to the environment and personal behaviors between 2002 and 2021 were extracted. The intervention themes were blood transfusion, postoperative pediatric nursing, postoperative hemorrhage and brain trauma nursing, basic and advanced life support, disaster nursing, and neonatal resuscitation. The primary outcomes were knowledge in five studies, satisfaction in one study, and competency in one study. The secondary outcomes were satisfaction in three studies, confidence in two studies, performance in two studies, skills in two studies, and self-efficacy, motivation, professional attitude, cognition, gameful experience, and affective response in one study each. Therefore, gamification interventions can be utilized in nursing practice education instead of traditional teaching methods such as lectures and face-to-face clinical practice.

A Behavior Test on a Frictional-Wedge-Type Vibration Isolation Device for Vibration Reduction of a Railway Track (열차 진동 저감을 위한 마찰쐐기형 방진장치의 거동 시험)

  • Lee, Chanyoung;Choi, Sanghyun;Lee, Yooin;Kwon, Segon;Koh, Yongsung;Ji, Yongsoo
    • Journal of the Society of Disaster Information
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    • v.11 no.1
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    • pp.45-54
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    • 2015
  • In the case of railway facilities in cities such as a railway station or a bridge, the significance of design for reducing vibration and noise is getting more significant. The vibration control solution is in need especially for an elevated railway station to block vibration of a train and secondary noise effectively. Even though a vertical vibration isolation device is able to be applied effectively to railway facilities such as elevated railway stations which transfer vibration directly from a train to a structure, the development of the vertical device is much slower than a horizontal vibration isolation device. In this paper, a vibration isolation device using wedge type friction material which is currently developing to reduce train-induced vibration effectively is introduced and test results for verification of dynamic performance is also presented. The vibration test on a concrete structure equipped with the developed vibration isolation device is conducted through which the isolation performance and dynamic properties are verified and needs for improving the performance of the device is identified.

Traits of Water Level Control by Sluice Gates and Halophyte Community Formation in Saemangeum (새만금 배수갑문 수위조절 특성과 염생식물 군락지 형성에 관한 연구)

  • Sin, Myoung-Ho;Kim, Chang-Hwan
    • Korean Journal of Environment and Ecology
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    • v.24 no.2
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    • pp.186-193
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    • 2010
  • In order to examine the traits of sluice gate water control, halophyte community formation and their inter-relations in Saemangeum, both water level condition and halophyte community formation were analyzed periodically and spatially on the topographic map with Surfer, Saemageum Spatial Analysis System, and related field reports. The traits of water level condition are that average water level in the growing period of halophytes was similar to annual average water level, annual low level and high level appeared in the growing period, and water level was usually maintained within a range of -1.0m~0.5m above mean sea level, but it has changed more frequently year by year. Routine water level control, natural disaster prevention, construction, and civil appeal took major percentages of the reasons for sluice gate's opening and shutting. Since 2007, not only the overall control frequency of sluice gate but also its control frequency for construction and natural disaster prevention have increased outstandingly. Halophyte community had formed at a rate of 1,209ha/year in the 4,315 ha land in 2008, 6.3 times larger than in 2005, and 2,382 ha above around 1.0m was estimated to be artificially vegetated, 89.1 % of the 2,673ha-size sown area. High water level was found to be a more possible determinant than average water level or low water level in halophyte community formation and it was thought to be secondary factors whether tillage was conducted or/and whether surface sealing formed.

Analysis of Availability of High-resolution Satellite and UAV Multispectral Images for Forest Burn Severity Classification (산불 피해강도 분류를 위한 고해상도 위성 및 무인기 다중분광영상의 활용 가능성 분석)

  • Shin, Jung-Il;Seo, Won-Woo;Kim, Taejung;Woo, Choong-Shik;Park, Joowon
    • Korean Journal of Remote Sensing
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    • v.35 no.6_2
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    • pp.1095-1106
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    • 2019
  • Damage of forest fire should be investigated quickly and accurately for recovery, compensation and prevention of secondary disaster. Using remotely sensed data, burn severity is investigated based on the difference of reflectance or spectral indices before and after forest fire. Recently, the use of high resolution satellite and UAV imagery is increasing, but it is not easy to obtain an image before forest fire that cannot be predicted where and when. This study tried to analyze availability of high-resolution images and supervised classifiers on the burn severity classification. Two supervised classifiers were applied to the KOMPSAT-3A image and the UAV multispectral image acquired after the forest fire. The maximum likelihood (MLH) classifier use absolute value of spectral reflectance and the spectral angle mapper (SAM) classifier use pattern of spectra. As a result, in terms of spatial resolution, the classification accuracy of the UAV image was higher than that of the satellite image. However, both images shown very high classification accuracy, which means that they can be used for classification of burn severity. In terms of the classifier, the maximum likelihood method showed higher classification accuracy than the spectral angle mapper because some classes have similar spectral pattern although they have different absolute reflectance. Therefore, burn severity can be classified using the high resolution multispectral images after the fire, but an appropriate classifier should be selected to get high accuracy.