• 대한족부족관절학회지
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• 제22권3호
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• pp.95-99
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• 2018

Purpose: The purpose of this study was to evaluate the radiologic outcomes of distal fibular fractures and to analyze the risk factors associated with nonunion. Materials and Methods: Between January 2009 and March 2016, 13 patients who had final nonunion with ankle fracture were included. In the control group, 370 patients who had undergone bony union and removed metal implants were included. All patients underwent the same surgical procedure and had the same treatment method, ultimately achieving satisfactory open reduction results with less than 2 mm fracture gap. Surgical treatment of fracture was considered to have the same effect on nonunion, and factors that might be associated with nonunion were evaluated. SPSS ver. 13.0 (SPSS Inc., USA) was used for all statistical analyses. Pearson's chi-square test and multi-variate regression analysis were performed to determine the factors affecting nonunion of distal fibular fracture. A p-value less than 0.05 was considered statistically significant, and relative risk was assessed. Results: The mean age of 13 patients was 46.9 years (range, 16~57 years); there were 8 men and 5 women. Among the 13 patients with nonunion, atrophic was the most common (12 cases). The association between the injury mechanism and the Lauge-Hansen classification and diabetes mellitus was not statistically significant. Distal fibular fractures with tibia shaft fracture (p=0.015) and Danis-Weber type C fracture (p=0.023), open fracture (p=0.011), and smoking (p=0.023) were significantly associated with nonunion. Conclusion: In this study, the combined injury of the ipsilateral tibia shaft fracture, open fracture, and Danis-Weber type C fracture may increase the possibility of nonunion. Therefore, caution is advised to prevent nonunion.

• 한국재난정보학회 논문집
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• 제15권1호
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• pp.20-27
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• 2019

연구목적: 본 연구에서는 국내 자동차 관련 화재발생 현황 및 위험성을 평가하고 초기 소화기구의 사용에 따른 피해저감 효과에 대해 평가하였다. 연구방법: 국내 자동차 화재의 발생 빈도에 대한 위험성 분석과 화재발생시 자동차에 비치되어 있는 소화기를 사용하여 초기 소화에 적용한 사용에 따른 인적 및 재산피해를 분석하였다. 연구결과: 국내 자동차 화재 발생에 따른 건당피해액은 연평균 증감률이 4.74%이고 매년 증가하는 것으로 나타났다. 자동차 화재현황 중 승용자동차에서 발생한 인명피해를 연도별 화재발생 건당 인명피해로 분석한 결과, 화재발생 100건당 재산피해액은 424.65만원에서 473.06만원으로 과거 5년간(2012년~2016년) 지속적으로 증가하는 추세를 보이고 있다. 결론: 승용자동차 화재시 소화기를 사용한 경우에는 화재발생 1건당 평균 재산피해액은 약 307.5만으로 산정되어 초기 자동차 화재에 차내에 비치된 소화기를 사용한 초기소화의 중요성과 필요성이 요구된다.

• 한국산학기술학회논문지
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• 제19권12호
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• pp.600-606
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• 2018

금속화재는 나트륨(Na), 리튬(Li) 등과 같은 가연성 금속이 연소하는 화재이다. 일반적인 물계, 가스계 소화약제에는 적응성이 없으며 금속화재용 소화약제 또는 건조사로 화재를 진화할 수 있다. 위험물안전관리법상 가연성 금속에 속하는 2류 및 3류 위험물 화재가 최근 5년간 104건이 발생했으며, 가연성 금속을 사용하는 연료전지, 반도체 산업의 발전으로 화재 건수는 더욱 증가할 것으로 예상되고 있다. 하지만 국내에는 금속화재와 관련된 법적 기준이 마련되어 있지 않아 금속화재용 소화약제 및 소화기 개발은 물론 화재 예방 및 대응 시스템 구축이 이루어지지 않고 있다. 이에 본 연구에서는 금속화재의 위험성을 감소시킬 수 있는 방안을 마련하기 위해 국내외 관련 법령 분석 및 금속화재 사례 11건을 분석하였다. 이를 통해 금속화재의 위험성을 감소를 위해 관련 법령 마련에 필요한 요소를 도출하였으며 금속화재 발생 시 소화약제로 사용되고 있는 건조사의 관리 및 지원방안을 제시하였다. 또한, 금속화재의 예방 및 대응에 필요한 안전교육 및 시설 관리 방안을 제시하였다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.136.1-136.1
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• 2011

An energy modeling analysis method currently has been considered as a new approach for energy policy research, because the importance of renewable energy use has been emphasized more and more. This study used RETScreen model as a clean energy decision making methodology for adaptation to climate change and elimination of various pollutions. This modeling method includes five step standard analysis; energy model, cost analysis, GHG analysis, financial analysis, and sensitivity & risk analysis and it also assesses both conventional and modern energy sources and technologies. This methodology for the photovoltaic(PV) energy modeling is used to evaluate the energy production, financial performance and GHG emissions reduction of photovoltaic projects. In addition, the PV application systems are classified into three basic applications; On-grid system, Off-grid system and water pumping system. This study assesses the renewable energy techno-economic modeling method with the feasibility analysis result of 10 MW PV power plant in Abu Dhabi in United Arab Emirates. Furthermore this study stresses the importance of renewable energy model research by applying to domestic PV power plant which is now in preparation.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 추계학술대회
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• pp.263-266
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• 1997

Three dimensional numerical model based on the finite element method(FEM) were developed to predict the mechanical behavior of hip implants. The purpose of this study is to investigate the stress distribution of two types of cementless total hip replacement femoral component -a straight stem and a curved stem, and to compare their effect on the stress shielding between two types by three dimensional finite element method. The authors analyzed von Mises stress in the cortex & stem and compared the stress between the straight and the curved stem. In comparison of stresses between two different design of femoral stem, there was 25% more decrease of stress in straight stem than curved stem in the medial cortex at proximal region. The straight stem had consistently much lower stresses than the curved stem throughout the whole medial cortex with maximum 70% reduction of stress. However, there was little change in stress between nature and 2 implanted femur throughout the lateral cortex. Stress of femoral stem was much higher in the straight stem than the curved stem up to 60%. The straight stem had more chance of stress shielding and a risk of fatigue fracture of the stem compared with the curved stem in noncement hip arthroplasty. In design of femoral stem still we have to consider to develop design to distribute more even stress on the proximal medial cortex.

• Computers and Concrete
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• 제11권4호
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• pp.271-289
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• 2013

In this research, a developed microstructural model of cement particles was presented to describe the cement hydration procedure. To simplify the hydration process, the whole hydration was analyzed in a series of sub-steps. In each step, the hydration degree, as well as the microstructural size of the hydration cell, was calculated as a function of the radius of the unreacted cement particles. With the consideration of the water consumption and the reduction of the interfacial area between water and hydration products, the micro-level expressions of the cement hydration kinetics were established. Then the heat released and temperature history of the concrete was carried out with the hydration degree obtained from each sub-steps. The equivalent age method based on the Arrhenius law was introduced in this research. Based on the equivalent age method, a maturity model was applied to describe the evolution of the mechanical properties of the material during the hydration process. The finite element program ANSYS was used to analyze the temperature field in concrete structures. Then thermal stress field was calculated using the elasticity modulus obtained from code formulate. And the risk of thermal cracking was estimated by the comparison of thermal stress and concrete tensile strength.

• 방사선산업학회지
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• 제17권1호
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• pp.111-118
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• 2023

The International Commission on Radiological Protection (ICRP) 103 recommends a cost-benefit analysis method as an auxiliary tool for scientific and rational decision-making for the principle of optimization of radiological protection. In order to conduct a cost-benefit analysis, the safety improvement of nuclear power by regulation must be measured and converted into monetary terms. The improvement of nuclear safety can be measured by reducing the radiation exposure dose of the people, and it is necessary to determine the coefficient to convert the radiation exposure dose into money. The monetary coefficient is calculated as the product of the statistical life value (VSL) and the nominal risk coefficient. In order to derive the monetary coefficient, the willingness to pay (WTP) can be estimated using the contingent valuation method (CVM), which quantifies the value of non-market goods by converting them into monetary units. WTP can be estimated based on the random utility model, which is the basic model for bivariate selection type conditional value measurement data. Statistical life value can be calculated using the estimated WTP and reduction in early mortality, and a monetary coefficient can be derived.

• 대한교통학회지
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• 제35권2호
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• pp.129-142
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• 2017

교통사고 잦은 곳 개선사업은 교통사고 예방을 위하여 도로상에 도로안전 관련 시설물을 설치함으로써 도로 환경적 요인에 대한 결함을 제거하는 대표적 교통안전개선사업이다. 그러나 개선사업으로 인해 설치된 각 시설물들에 대한 효과평가에 대한 연구는 미비하였다. 따라서 본 연구에서 도로 교통안전 관련 시설물의 교통사고 감소효과도를 추정하기 위하여 최근 2004년부터 2013년까지 교통사고 잦은 곳 개선사업 공사가 완료된 4,171개 지점을 대상으로 비교그룹방법을 활용하여 5가지 시설물에 대한 교통사고 감소효과도를 추정하였다. 분석 결과, 전체 교통사고에 대해서는 교통섬 4.45%, 표지병 32.17%, 과속단속카메라 24.13% 사고감소 효과를 나타냈으며, 반면 무단횡단금지시설 0.61%, 미끄럼방지포장은 1.67% 만큼 증가한 것으로 나타났다. 또한 표지병, 무단횡단금지시설, 미끄럼방지포장과 같이 국토교통부의 "도로안전시설 설치 및 관리지침"에서 특정유형의 교통사고 예방에 효과가 있다고 언급된 시설물들의 교통사고 감소효과도를 추가적으로 분석하였다. 그 결과, 표지병은 악천후 시 교통사고에 대해서 52.96%, 무단횡단금지시설은 차대보행자 교통사고에 대해서 62.77%, 미끄럼방지포장은 추돌사고에 대해서 26.60%의 순수 교통사고 감소효과가 있는 것으로 분석되었다.

• 한국재난정보학회 논문집
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• 제17권2호
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• pp.365-374
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• 2021

연구목적: 본 연구는 발주기관과 사내 공급자의 재해경감활동관리체계 연계성 강화에 대하여 연구하고자 한다. 연구방법: 기업재난관리표준에 정하고 있는 공급자 전략에 대한 요구사항을 파악하고, A기관과 공급자B의 적용사례를 검토 분석하여 재해경감활동관리체계의 연계성 강화를 위한 절차를 도출하였다. 연구결과: 기업재난관리표준의 요구사항인 공급자 전략에 대하여 명확히 정의하고, 연계성 강화를 위해서 발주기관과 공급자가 적용하는 절차와 그 절차에 의하여 산출된 결과물을 공유하는 표준화된 절차가 필요한 것으로 연구되었다. 결론: 사내에 상주하는 공급자의 재해경감활동관리체계 수립 절차중 중요한 절차의 연계성 강화를 위한 개선안을 제안하였으며, 제안된 내용과 절차를 기업재난관리표준과 관련 규범에 반영할 것을 제시하였다.

• 항공우주시스템공학회지
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• 제1권2호
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• pp.13-20
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• 2007

Structural qualification plan (SQP) for aerospace vehicle is based on material certification methodology, which must be approved by certification authority. It is internationally required to use of statistically based material allowables to design aerospace vehicles with aerospace materials. In order to comply with this regulation, it is necessary to establish relatively large amount of database, which increases test costs and time. Recently NASA/FAA develop the new methodology which results in cost, time, and risk reduction, and satisfies the regulation at the same time. This paper summarizes the certification methodology of materials system as a part of structural qualification plan (SQP) of aerospace vehicles and also thermal management of the vehicle system, like thermal protection materials system and thermally conductive material system. Materials design allowable was determined using this method for a carbon/epoxy composite material.