• Title/Summary/Keyword: Hazard increase

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Numerical Simulation for Urban Climate Assessment and Hazard (도시기후 평가와 방재를 위한 도시기상 수치모의)

  • O, Seong-Nam
    • Magazine of the Korean Society of Hazard Mitigation
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    • v.2 no.4 s.7
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    • pp.40-47
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    • 2002
  • Since it is important to understand the bio-climatic change in Seoul for ecological city planning in the future, this paper gives an overview on bio-climate analysis of urban environments at Seoul. We analyzed its characteristics in recent years using the observations of 24 of Automatic Weather Station (AWS) by Korea Meteorological Administration (KMA). In urbanization, Seoul metropolitan area is densely populated and is concentrated with high buildings. This urban activity changes land covering, which modifies the local circulation of radiation, heat and moisture, precipitation and creating a specific climate. Urban climate is evidently manifested in the phenomena of the increase of the air temperature, called urban heat Island and in addition urban sqall line of heavy rain. Since a city has its different land cover and street structure, these form their own climate character such as climate comfort zone. The thermal fold in urban area such as the heat island is produced by the change of land use and the air pollution that provide the bio-climate change of urban eco-system. The urban wind flow is the most important climate element on dispersion of air pollution, thermal effects and heavy shower. Numerical modeling indicates that the bio-climatic transition of wind wake in urban area and the dispersion of the air pollution by the simulations of the wind variation depend on the urban land cover change. The winds are separately simulated on small and micro-scale at Seoul with two kinds of kinetic model, Witrak and MUKLIMO.

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A Study on the Improvement of Classification of Explosion Hazardous Area using Hypothetic Volume through Release Characteristic (누출특성을 통한 폭발위험장소 선정방법의 개선에 대한 연구)

  • Kim, Dae-Yeon;Chon, Young-Woo;Lee, Ik-Mo;Hwang, Yong-Woo
    • Journal of the Korea Safety Management & Science
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    • v.19 no.2
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    • pp.31-39
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    • 2017
  • Classify of explosion hazardous areas must be made at the site where flammable materials are used. This reason is that it is necessary to manage ignition sources in of explosion hazardous areas in order to reduce the risk of explosion. If such an explosion hazard area is widened, it becomes difficult to increase the number of ignition sources to be managed. The method using the virtual volume currently used is much wider than the result using CFD(Computational Fluid Dynamics). Therefore, we tried to improve the current method to compare with the new method using leakage characteristics. The result is a realistic explosion hazard if the light gas is calibrated to the mass and the heavy gas is calibrated to the lower explosion limit. However, it is considered that the safety factors should be taken into account in the calculated correction formula because such a problem should be considered as a buffer for safety.

Effect of Applying Pretreatment Methods before cooking for decreasing the Microbiological Hazard of Cooked Dried fish in Foodservice establishments (건어물을 이용한 조리음식의 미생물학적 위해 감소를 위한 조리 전처리 적용 효과)

  • 배현주;이재학;오세인
    • Korean journal of food and cookery science
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    • v.19 no.5
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    • pp.555-561
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    • 2003
  • The purpose of this study was to analyze the microbiological hazards of dried fish (Jwieochae, Ojingeochae and Bugeochae), and to apply pretreatment methods to increase the safety of cooked dried fish within foodservice establishments. Microbiological inspections were conducted on Total Plate Count, Coliforms, E. coli, E. coli O157:H7, Staphylococcus aureus, Salmonella spp. and Listeria monocytogenes. The study results are summarized as follows. According to the Hazard analysis, there are many problems showing high numbers in terms of Total Plate Count and Coliforms, which were both well over acceptable standard levels. E. coli and Staphylococcus aureus were detected at certain foodservice establishments, while E. coli O157:H7, Salmonella spp. and Listeria monocytogenes were not detected at all. By applying various pretreatment methods, such as washing, blanching, pan frying and microwave heating, the levels of microbiological hazards were able to be controlled and lowered. Blanching was the most effective method, followed by panfrying, microwave heating and washing. The Total Plate Counts gradually decreased with increasing number of times washed and seconds panfried. From these results, it is concluded that to guarantee food safety, cooked dried fish raw materials should be kept hygienically and appropriate pretreatment methods applied before cooking.

The Hazard Analysis and Critical Control Point (HACCP) System and Its Implementation in an Aseptic Thermal Juice Processing Scheme: A Review

  • Min, Sea-Cheol;Min, David B.
    • Food Science and Biotechnology
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    • v.15 no.5
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    • pp.651-663
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    • 2006
  • Hazard Analysis and Critical Control Point (HACCP), a systematic process that identifies, assesses, and controls hazards, has been developed as an effective alternative to conventional end-point analysis for food safety control. The importance of HACCP has been emphasized recently due to the development of new food processing technologies and the increase in international trade demanding worldwide of food product safety. This paper provides a review of HACCP and a generic HACCP template for its implementation for aseptic processing of a juice drink.

A Study on Construction policy for Seoul Metropolitan Railway (서울 도시철도 건설방향에 대한 연구)

  • Woo, Nam-Jik;Lee, Won-Young
    • Journal of the Korean Society of Hazard Mitigation
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    • v.8 no.6
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    • pp.67-71
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    • 2008
  • This study is to retest of seoul traffic, all sorts of statistical data, the present condition of urban railway that local government and all sorts of research institution had researched. Even though, or something else with population and regional industrial distribution of seoul with worker and the present condition of the registrated cars and the change of increase, we have predicted the medium term and long-range solution. we have proposed the alternative plan about both of the problem that is the developmental construction direction of seoul urban railway and the resource insurance for urban railway construction.

A Study on Potential Risk of Landslide in Pusan (부산지역의 산사태 위험 연구)

  • Lee, Su-Gon
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.2 no.2
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    • pp.9-23
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    • 1999
  • Pusan's reputation as the nation's most crowded city in terms of population density is attributable to its huge mountains which allow only small portion of residential area to its large population. Rapid increase of urban population on limited amount of land had naturally led its developments efforts to mountainous area giving rise to the concern of potential landslide. This study on urban Pusan and "Landslide Hazard Map" thereof is prepared in an attempt to avoid disasters created by landslide and also as a reference for city planners. The Map shows that the area covering 38% to 43% of urban Pusan has the potential for landslide. The study also shows that various civil works involving massive land excavation had been more direct cause of landslides in Pusan than such traditional factors as locations, ground slopes, rock types and topography of the area concerned.

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Impact spectrum of flood hazard on seismic vulnerability of bridges

  • Yilmaz, Taner;Banerjee, Swagata
    • Structural Engineering and Mechanics
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    • v.66 no.4
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    • pp.515-529
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    • 2018
  • Multiple hazards (multihazard) conditions may cause significant risk to structures that are originally designed for individual hazard scenarios. Such a multihazard condition arises when an earthquake strikes to a bridge pre-exposed to scour at foundations due to flood events. This study estimates the impact spectrum of flood-induced scour on seismic vulnerability of bridges. Characteristic river-crossing highway bridges are formed based on the information obtained from bridge inventories. These bridges are analyzed under earthquake-only and the abovementioned multihazard conditions, and bridge fragility curves are developed at component and system levels. Research outcome shows that bridges having pile shafts as foundation elements are protected from any additional seismic vulnerability due to the presence of scour. However, occurrence of floods can increase seismic fragility of bridges at lower damage states due to the adverse impact of scour on bridge components at superstructure level. These findings facilitate bridge design under the stated multihazard condition.

Interaction effect of Chemical Mixtures (혼합물에서 화학물질간의 상호작용 효과)

  • Leem Jong Han;Shin Joo-Youn;Kim Yong-Kyu
    • Journal of The Korean Society of Clinical Toxicology
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    • v.3 no.1
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    • pp.11-16
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    • 2005
  • Chemical mixtures of components, each of which are present at less than guidance concentrations, may be hazardous due to additivity, interactions, or both. Toxicological interactions may increase the health hazard above what would be expected from an assessment of each component singly, or all components additively. So chemical mixture are a particular issue in public health. There are several approach to assess whether there are additivity or interaction in assessing toxicological effects, such as, components-based approach, physiologically-based pharmacokinetic /pharmacodynamic(PBPK/PD) models, hazard index method, and weight-of evidence method. If we consider interaction or additivity effects in assessing the health effects of chemcial mixtures, we can get more accurate information about toxicological effects and dose-response relationship in chemical mixtures.

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Development of an earthquake-induced landslide risk assessment approach for nuclear power plants

  • Kwag, Shinyoung;Hahm, Daegi
    • Nuclear Engineering and Technology
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    • v.50 no.8
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    • pp.1372-1386
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    • 2018
  • Despite recent advances in multi-hazard analysis, the complexity and inherent nature of such problems make quantification of the landslide effect in a probabilistic safety assessment (PSA) of NPPs challenging. Therefore, in this paper, a practical approach was presented for performing an earthquake-induced landslide PSA for NPPs subject to seismic hazard. To demonstrate the effectiveness of the proposed approach, it was applied to Korean typical NPP in Korea as a numerical example. The assessment result revealed the quantitative probabilistic effects of peripheral slope failure and subsequent run-out effect on the risk of core damage frequency (CDF) of a NPP during the earthquake event. Parametric studies were conducted to demonstrate how parameters for slope, and physical relation between the slope and NPP, changed the CDF risk of the NPP. Finally, based on these results, the effective strategies were suggested to mitigate the CDF risk to the NPP resulting from the vulnerabilities inherent in adjacent slopes. The proposed approach can be expected to provide an effective framework for performing the earthquake-induced landslide PSA and decision support to increase NPP safety.

Hazard Identification and Testcase Design Method based on Use Case and HAZOP (사용사례와 HAZOP 기반의 위험원 식별 및 테스트케이스 설계 방안)

  • Do, Sungryong;Han, Hyuksoo
    • Journal of KIISE
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    • v.43 no.6
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    • pp.662-667
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    • 2016
  • As electric and electronic control systems have sharply increased in vehicles, safety accident has emerged as an important issue. Therefore, in order to ensure safety of the vehicle, engineers are required to identify the hazards utilizing PHA and HAZOP, etc. in the early phase of development and implement safety mechanisms to prevent them. HAZOP has been widely used in a systematic manner based on guidewords. However, HAZOP identifies malfunctions from the top-level functionality provided by the system, so it cannot sufficiently identify hazards during the system operation. This leads to restrictions in designing testcases, because the safety requirements are derived from only some of the hazards. This research aimed to provide a hazard identification method utilizing Use case description, which defines operation procedure of the system and HAZOP and a testcase design method based on safety requirements. We introduced a case study on Smart Key Control System in vehicles and compared with hazards identification results based on HAZOP, to demonstrate the effectiveness of this study. The result of this study could potentially reduce development cost and increase system quality by adequately identifying hazards and safety requirements and designing the related testcase.