• 한국산학기술학회논문지
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• 제13권11호
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• pp.5558-5565
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• 2012

도로 방호울타리는 차량의 이탈을 방지하는 시설로, 도로의 형태나 제한속도 등을 기준으로 하여 7 종류의 방호울타리를 규정하고 있다. 하지만, 최근 차량의 성능이 향상되면서 과적, 과속의 위험이 있고, 국내외 방호울타리 관련 차량사고를 보면 추락사고가 빈번하게 발생하고 있어, 현재의 방호울타리 설계충격도가 다소 부족한 것으로 나타나고 있다. 본 연구에서는 고속도로에 주로 적용하는 SB5 강재 방호울타리와 SB6 콘크리트 방호울타리의 차량방호 성능을 검증하기 위하여 차량충돌해석을 수행하여, 방호울타리의 파괴 및 차량전도 조건을 산출하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.374-377
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• 2005

Automobile is in charge of most transportation system in modern urban city. However, in fact, cause of problem of road state, environment, and the other reasons, urban transit system is using as Mass Transit nowadays. Nevertheless Urban transit system is considering many kind of safety fact of that system which is increasing continuously nowadays, it occurs various train accident. This paper describes 3D Dimensional Measurement(EDM testing) and tensile testing results of carbody structure for crashed EMU(Electric Multiple Units). Tensile tests were performed on two different types of specimens in order to evaluate the strength changes before and after damages, obtained from plastic deformed area and nondeformed region of the crashed EMU. And Structural analysis of EMU was performed for the criteria of safety assessment. Structural analysis using commercial I-DEAS software provided important information on the stress distribution and load transfer mechanisms as well as the amount of damages during rolling stock crash. The testing results have been used to provide the critical information for the criteria of safety diagnosis.

• 한국도로학회논문집
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• 제14권4호
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• pp.93-101
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• 2012

PURPOSES : Adverse weather conditions such as heavy rain, heavy snowfall, and thick fog and so on have highly affect on the change in traffic conditions on the road. In particular, heavy snowfall causes capacity reduction as well as crash occurrence. This study investigated the effects of snowfall on speed on a freeway. METHODS : Vehicle detection systems data were matched with corresponding weather station data by regression analysis. RESULTS : The results show that the travel speed is reduced by 6.7% under little snowfall and by 12.8% under heavy snowfall. Regarding the speed variation, 8.7% and 114.7% increases are observed under little snowfall and heavy snowfall, respectively. It is also found that 1 cm increase in snowfall leads to 0.4% decrease in travel speed. In addition, the travel speed increases by 0.4% when the temperature increases by $1^{\circ}C$. CONCLUSIONS : It is expected that the outcome of this study will be useful in establishing more effective strategies for winter operations and road maintenance in practice.

• 한국시뮬레이션학회논문지
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• 제23권4호
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• pp.151-161
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• 2014

군에서 향후 미래 위협에 대비한 군용 항공기의 적정 소요를 분석하는 일은 중요하다. 이전의 연구들은 작전 임무수행 측면과 전력지수의 비교를 통하여 적정 소요를 분석하였다. 이 방법들은 단편적인 항공기의 전투-효과 지수와 수량 측면에서의 비교만을 실시하였다. 그러나 본 연구에서는 시스템 다이내믹스를 통한 군용 항공기의 실제 운용 시나리오에 기반한 시뮬레이션 분석을 실시한다. 군용 항공기 운용 개념의 특성을 반영하여 하부 주요 시스템의 고장률과 수리율, 전 평시 차별적으로 발생하는 피격률을 통해 적정 소요량을 산출한다.

• 응용통계연구
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• 제21권4호
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• pp.603-613
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• 2008

셀 수 있는 이산 자료 중에서 일반적인 모형에 비하여 영의 빈도가 과도하게 많이 관측되는 자료가 있다. 이러한 경우에 포아송 또는 음이항회귀모형과 같은 일반적인 회귀모형에 의한 분석은 적절하지 못하다. 본 논문에서는 영과잉 포아송회귀모형과 영과잉 음이항회귀모형에 대하여 베이지안 분석을 하였다. 또한, 마코브 연쇄 몬테카롤로 방법으로 계산한 베이즈 요인을 이용하여 모형선택을 하였다. 실제 교통사고 자료를 분석하여 이론적인 결과들을 뒷받침하였다.

• 대한기계학회논문집A
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• 제29권6호
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• pp.913-920
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• 2005

Compared to previous in-vitro test, FE model showed reliable motion patterns. A finite element model of a 50th percentile male neck was developed to study the mechanics of whiplash injury while the rear impacts. The model was consisted of the whole cervical vertebrae including part of occipital, intervertebral discs. which were modeled using linear viscoelastic materials and posterior elements. The sliding interfaces were defined to simulate contact phenomena in facet joints and in odontoid process. All ligaments and atlanto-occipital membrane were modeled as nonlinear bar elements. Only muscle elements were not considered. Motion of each cervical vertebra was obtained from the dynamic simulation with a MADYMO model for 15 km/h $40\%$ rear end offset impacts. Soft tissue neck injury(STNI) was investigated with a developed FE model. In FE model analysis, the high stress was appeared at C3/C4 disc in offset impact. Further research is still needed in order to improve the developed neck FE model for many different crash patterns.

• Applied Science and Convergence Technology
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• 제24권2호
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• pp.27-32
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• 2015

We analyzed the destruction patterns of a turbo-molecular pump (TMP) resulting from its sudden exposure of a foreline to the atmospheric pressure due to a destruction of the foreline connecting clamp of an ICP dry etcher for 300 mm wafers during high-vacuum operation ($5{\times}10^{-6}$ Torr). Unlike in the case of view port's breakage, the TMP's rotor module was crashed inside the chamber. The primary damage resulted from the collision of the blades and stators, and the secondary damage resulted from the breaking of the rotor - driving shaft assembly. The fixing screws of the rotor and axial shaft were bent and broken when the TMP controller output the maximum current even after the crash event. Electrical power consumption analysis of the TMP power controller confirmed it. The stress distributions were analyzed by a finite element method using CFD-ACE+ multi physics software. Rotating inertia of each parts and kinetic energies were calculated as well. 68% of the rotational kinetic energy is deposited by the rotor - shaft module.

• 한국자동차공학회논문집
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• 제25권2호
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• pp.242-249
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• 2017

In this study, the relationship between the shape of a passenger airbag and the possibility of injury is analyzed using the Taguchi method. The optimal shape combination is proposed for a design guideline that can reduce the possibility of injury to the dummy. The airbag FE model for analysis is obtained using a CAD system that can change the shape through several independent variables. The widths of the left / right, top / bottom, and back / forth direction of the airbag shape are set as the design factors, and the effect of the combination injury probability according to the shape is analyzed. The minimum geometric combinations are obtained using the orthogonal array method. The signal to noise ratio is calculated and the optimal shape combination is obtained through sensitivity analysis. The obtained optimal shape combination is compared with the possibility of injury of the initial airbag shape to confirm improved airbag performance.

• 한국자동차공학회논문집
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• 제14권3호
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• pp.22-27
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• 2006

As the regulation and assessment program for safety of passengers become stringent, automakers are required to develop lighter and safer vehicles. In order to fulfill both requirements which conflict with each other, automobile and steel companies have proposed the application of AHSS(Advance High Strength Steel) such as DP, TRIP and martensite steel. ULSAB-AVC model is one of the most remarkable reactions to offer solutions with the use of steel for the challenge to improve simultaneously the fuel efficiency, passenger safety, vehicle performance and affordability. This paper is concerned with the crash analysis of ULSAB-AVC model according to the US-SINCAP in order to compare the effectiveness between the model with AHSS and that with conventional steels. The crashworthiness is investigated by comparing the deformed shape of the cabin room, the energy absorption characteristics and the intrusion velocity of a car.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제20권1호
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• pp.27-34
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• 2014

Purpose: The purpose of this study was to identify the role of the physical environment in task interruptions in the healthcare settings. Many dangerous events such as airplane crash and medical errors are the result of human errors and, these errors are often the result of interruptions during a critical task of professional workers. In fact, the physical environment that determines accessibility and visibility among people affects interruptions significantly, but architectural studies have given little attention to the management of interruptions. Methods: Therefore, the researcher reviewed research literature in other fields to find out how the physical environment affected interruptions. Many studies were from management, human factors, and health care, but few from architecture. First the author examined the impact of interruptions, second described the social context of interruptions and the role of the physical environment. Results: Findings included that description of the physical environment was not very clear in studies from management and human factors, while little work had been done on interruptions in architecture. The author proposed study design that compensated shortcomings of each field by combining approaches from management, human factors, and architecture. Implications: Unit design strategies such as distributed nurse stations can affect interruptions and layout analysis such as space syntax analysis can evaluate visibility and accessibility of floor plans in the preliminary design phase.