• Title/Summary/Keyword: Hazard Factors

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외국인투자기업 생존율 및 영향요인 (Survival Factors and Survival Rates of Foreign-invested Companies)

  • 성길용
    • 한국콘텐츠학회논문지
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    • 제19권5호
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    • pp.287-295
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    • 2019
  • 본 연구는 국내시장 외국인투자기업의 생존율과 영향요인 연구로서 2006년부터 2017년까지 NICE평가정보(주) Kis Value의 외국인투자법인 자료를 바탕으로 실증했다. 외국인투자지분, 수출 유무, 제조업 구분을 더미 변수로 변환한 요인과 근로자 수, R&D집중도 요인을 기업특성변수로 설정했다. 또한, 자본, 자산, 부채요인을 안정성변수로 매출이익, 당기순이익, 영업이익을 수익성변수로 구분해 기업의 재무적 특성변수로 설정했다. 영향요인 분석에는 콕스-비례 위험 모형을 생존율 비교에는 생명표 법을 사용했다. 분석 결과 외국인투자지분, 근로자 수, 매출이익, 당기순이익, 영업이익 요인이 기업생존에 정(+)의 영향요인으로 작용했다. 또한, 추가적 분석에서 자산요인은 정(+)의 영향 관계로 자본과 부채 요인은 부(-)의 영향 관계로 조사되었으며, 수출 유무, 제조업 구분과 R&D집중도는 유의수준을 벗어나는 영향 관계로 분석되었다. 기업특성변수 중 유의한 영향요인인 외국인투자지분의 더미 변수를 활용한 생존율 비교분석에서는 100% 외국인투자 지분기업이 외국인투자 합작기업과 비해 높은 생존율과 상대적으로 긴 생존 기간으로 조사되었으며, 기업의 사멸밀도도 낮은 것으로 분석되었다.

Methylthioisocyanate 합성반응 공정의 열적위험 특성 (Characteristics of Thermal Hazard in Methylthioisocyanate Synthesis Reaction Process)

  • 한인수;이근원;이주엽
    • 한국안전학회지
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    • 제27권5호
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    • pp.77-87
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    • 2012
  • Compared to a batch reactor, where all reactants are initially charged to the reactor, the semi-batch reactor presents serious advantages. The feed of at least one of the reactants provides an additional way of controlling the reaction course, which represents a safety factor and increases the constancy of the product quality. The aim of this study was to investigate the characteristics of thermal hazard such as a feed time, catalysis concentration and solvent concentration in methylthioisocyanate(MTI) synthesis reaction process. The experiments were carried out by the Multimax reactor system and Accelerating rate calorimeter(ARC). The MTI synthesis reaction process has many reaction factors and complicated reaction mechanism of multiphase reaction. Through this study, we can use as a tool for assessment of thermal hazard of other reaction processes by applying experiment method provided.

표고 데이타베이스에 의한 산사태 위험평가의 기초적 연구 (A Foundmental Study on the Landslide Hazard Assessment Using Database of Ground Height)

  • 강인준;이홍우;곽재하;정재형
    • 대한토목학회논문집
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    • 제13권2호
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    • pp.211-218
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    • 1993
  • 산사태는 발생빈도는 적으나 자연적 요인이나 인위적인 요인에 의한 사면의 안정파괴시 많은 인명 및 재산상의 손실을 유발시킨다. 최근 산사태 발생지역 예측을 위한 통계적 방법과 현장관측 방법 등의 연구가 지속적으로 진행되고 있으나 발생체계의 복잡성으로 많은 어려움이 있다. 본 연구에서는 산사태 위험지역 예측을 하기위해 산사태가 발생한 지역을 모델 지역으로 선정하였다. 모델 지역의 지형을 축척 1 : 25,000, 1 : 10,000, 1 : 5,000, 1 : 1,200별 비교를 하기위해 표고를 데이타베이스화하여 표고 및 경사도의 경중률에 의한 예측을 한 결과 부분적인 예측이 가능함을 알 수 있었다.

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시멘트 혼화제 제조시 에스테르화공정의 열 안정성 평가 (An Evaluation of Thermal Stability on Esterification Process in Manufacture of Concrete Mixture Agents)

  • 이근원;이정적;최이락;한인수
    • 한국안전학회지
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    • 제24권4호
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    • pp.40-46
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    • 2009
  • The early identification of thermal hazards associated with a process such as the heats of reaction, exothermic decompositions, and the understanding of thermodynamics before any large scale operations are undertaken. The evaluation of reaction factors and thermal behavior on esterification process in manufacture of concrete mixture agents are described in the present paper. The experiments were performed in the differential scanning calorimetry(DSC), C 80 calorimeter, and thermal screening unit($TS^u$). The aim of the study was to evaluate the thermal stability of single material and mixture in esterification process. We provided the thermal data of chemical materials to present safe operating conditions through this study.

Modeling and simulation of large crowd evacuation in hazard-impacted environments

  • Datta, Songjukta;Behzadan, Amir H.
    • Advances in Computational Design
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    • 제4권2호
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    • pp.91-118
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    • 2019
  • Every year, many people are severely injured or lose their lives in accidents such as fire, chemical spill, public pandemonium, school shooting, and workplace violence. Research indicates that the fate of people in an emergency situation involving one or more hazards depends not only on the design of the space (e.g., residential building, industrial facility, shopping mall, sports stadium, school, concert hall) in which the incident occurs, but also on a host of other factors including but not limited to (a) occupants' characteristics, (b) level of familiarity with and cognition of the surroundings, and (c) effectiveness of hazard intervention systems. In this paper, we present EVAQ, a simulation framework for modeling large crowd evacuation by taking into account occupants' behaviors and interactions during an emergency. In particular, human's personal (i.e., age, gender, disability) and interpersonal (i.e., group behavior and interactions) attributes are parameterized in a hazard-impacted environment. In addition, different hazard types (e.g., fire, lone wolf attacker) and propagation patterns, as well as intervention schemes (simulating building repellent systems, firefighters, law enforcement) are modeled. Next, the application of EVAQ to crowd egress planning in an airport terminal under human attack, and a shopping mall in fire emergency are presented and results are discussed. Finally, a validation test is performed using real world data from a past building fire incident to assess the reliability and integrity of EVAQ in comparison with existing evacuation modeling tools.

Discrete-time Survival Analysis of Risk Factors for Early Menarche in Korean Schoolgirls

  • Yong Jin Gil;Jong Hyun Park;Joohon Sung
    • Journal of Preventive Medicine and Public Health
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    • 제56권1호
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    • pp.59-66
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    • 2023
  • Objectives: The aim of this study was to evaluate the effect of body weight status and sleep duration on the discrete-time hazard of menarche in Korean schoolgirls using multiple-point prospective panel data. Methods: The study included 914 girls in the 2010 Korean Children and Youth Panel Study who were in the elementary first-grader panel from 2010 until 2016. We used a Gompertz regression model to estimate the effects of weight status based on age-specific and sex-specific body mass index (BMI) percentile and sleep duration on an early schoolchild's conditional probability of menarche during a given time interval using general health condition and annual household income as covariates. Results: Gompertz regression of time to menarche data collected from the Korean Children and Youth Panel Study 2010 suggested that being overweight or sleeping less than the recommended duration was related to an increased hazard of menarche compared to being average weight and sleeping 9 hours to 11 hours, by 1.63 times and 1.38 times, respectively, while other covariates were fixed. In contrast, being underweight was associated with a 66% lower discrete-time hazard of menarche. Conclusions: Weight status based on BMI percentiles and sleep duration in the early school years affect the hazard of menarche.

기후변화 대응을 위한 광역도시권 차원의 자연재해 저감방안 연구 -자연재해 취약성에 따른 수도권 도시의 유형화- (Classification of Cities in the Metropolitan Area based on Natural Hazard Vulnerability)

  • 심재헌;김자은;이성호
    • 한국산학기술학회논문지
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    • 제13권11호
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    • pp.5534-5541
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    • 2012
  • 본 연구의 목적은 자연재해 취약성에 근거하여 수도권 도시를 유형화하고, 유형별 특성에 따른 차별적인 자연재해 저감방안을 제시하는데 있다. 본 연구의 실증분석은 자연재해 취약성 요인의 추출, 요인득점을 이용한 수도권 도시의 유형분류, 유형화 결과에 기초한 차별적인 자연재해 저감방안 제시라는 세 단계로 구성되었다. 보다 구체적으로 주성분분석의 결과 고유치가 1 이상인 유의미한 요인은 3개로 추출되었고, 이들은 각각 자연재해에 대한 지형적 내재해성, 비도시성, 재해예방능력을 나타내는 요인으로 특징지을 수 있었다. 지역별 요인득점을 이용한 k-medians 비계층적 군집분석의 결과 사례지역은 지형적으로 자연재해에 취약하고 재해예방능력이 미흡한 지역, 시가화지역으로서 재해예방능력이 양호한 지역, 비도시지역으로서 지형적으로 자연재해에 취약한 지역, 자연재해에 대한 지형적 내재해성을 갖고 있으나 재해예방능력이 미흡한 지역이라는 4개의 군집유형으로 분류되었다. 끝으로 수도권 내 유형별 특성을 고려한 차별적인 자연재해 저감방안이 제시되었다.

국가 화학물질 유해성정보 데이터베이스 구축 과정의 신뢰도 제고 방안에 관한 연구 (Improving the Reliability of the National Database for Chemical Hazard Information)

  • 이소민;이민혁;강미진;권순광;나진성;박백수
    • 한국환경보건학회지
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    • 제46권4호
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    • pp.410-422
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    • 2020
  • Objectives: According to the Act on Registration, Evaluation, Etc. of Chemicals, new and existing chemicals must be registered by 2030. In addition, industries need to submit hazard data as an attachment during the registration process. Therefore, we constructed a nationwide chemical database to support small industry by providing hazard data and original sources. During the process, we developed a new standard procedure for minimizing errors and increasing reliability. Methods: We analyzed the categories of errors and the cause of the errors through the verification results of the 2019 project. We present an improved database construction methodology and system. Results: Errors are categorized according to their causative factors into simple, technical, and structural type errors. Simple errors arise simply because of decreased concentration or negligence in following the instructions. Technical errors are caused by a discrepancy between the professional field and the type of data. Structural errors indicate systemic errors such as incomplete forms on the excel database or ambiguity in the guidelines. Lessons from the errors collected in the 2019 project are used to update the procedures for database authorization and technical guidelines. The main update points are as follows; 'supplementation of review process', 'giving regular training to external reviewers', 'giving additional information to authors, like physico-chemical properties of substances, degradability, etc.', 'amendment of excel form', and 'guideline upgrades'. Conclusions: We conducted this study with the aim of improving the accuracy and reliability of the database of hazard information for chemical substances. The new procedures and guidelines are now being used in the 2020 project for construction of a hazard information database for Korea.

GIS 기반의 뿌리보강모델을 활용한 산사태 위험도 작성방법 연구 (GIS Landslide Hazard Mapping Using Root Strength Reinforcement Model)

  • 김민구;윤영진;장훈
    • 대한공간정보학회지
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    • 제13권1호
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    • pp.45-53
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    • 2005
  • 우리나라는 전 국토의 약 70%가 산지로 구성되어 있고, 장마 및 태풍 등에 의해 산사태가 매년 발생하여 큰 피해를 주고 있는 실정이다. 이것은 또한, 도시의 팽창과 더불어 산업화의 발전에 의해서도 해마다 그 발생횟수가 증가하고 있다. 2002년 8월 발생한 태풍 루사는 우리나라 곳곳에 심각한 영향을 끼쳤으며, 특히 강원도 강릉 지역에 가장 큰 피해를 야기했다. 이런 위험 지역의 삼림이나 산사태 관리를 위해 산사태 위험도가 반드시 필요하다고 여겨진다. 지리정보 시스템(GIS)은 산사태 위험도를 제작하기에 시간 뿐 아니라, 노동력과 비용을 경감시킬 수 있을 뿐만 아니라, 위험 지역에 대한 조사와 공간적 예측 모델을 구축하는데 효과적으로 활용될 수 있다. 다양한 방법들로 산사태 위험도를 제작할 수 있다. 본 연구에서는, 뿌리보강 모델을 활용하였다. 이 모델은 경사도, 토심, 토양의 특성과 식생과 같은 인자들을 활용하여 산사태 위험도를 작성하였다.

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Fuzzy-based multiple decision method for landslide susceptibility and hazard assessment: A case study of Tabriz, Iran

  • Nanehkaran, Yaser A.;Mao, Yimin;Azarafza, Mohammad;Kockar, Mustafa K.;Zhu, Hong-Hu
    • Geomechanics and Engineering
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    • 제24권5호
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    • pp.407-418
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    • 2021
  • Due to the complexity of the causes of the sliding mass instabilities, landslide susceptibility and hazard evaluation are difficult, but they can be more carefully considered and regionally evaluated by using new programming technologies to minimize the hazard. This study aims to evaluate the landslide hazard zonation in the Tabriz region, Iran. A fuzzy logic-based multi-criteria decision-making method was proposed for susceptibility analysis and preparing the hazard zonation maps implemented in MATLAB programming language and Geographic Information System (GIS) environment. In this study, five main factors have been identified as triggering including climate (i.e., precipitation, temperature), geomorphology (i.e., slope gradient, slope aspect, land cover), tectonic and seismic parameters (i.e., tectonic lineament congestion, distribution of earthquakes, the unsafe radius of main faults, seismicity), geological and hydrological conditions (i.e., drainage patterns, hydraulic gradient, groundwater table depth, weathered geo-materials), and human activities (i.e., distance to roads, distance to the municipal areas) in the study area. The results of analyses are presented as a landslide hazard map which is classified into 5 different sensitive categories (i.e., insignificant to very high potential). Then, landslide susceptibility maps were prepared for the Tabriz region, which is categorized in a high-sensitive area located in the northern parts of the area. Based on these maps, the Bozgoosh-Sahand mountainous belt, Misho-Miro Mountains and western highlands of Jolfa have been delineated as risk-able zones.