• 한국소음진동공학회논문집
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• 제16권7호
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• pp.754-761
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• 2006

This paper presents the dynamic characteristics of MR impact damper for vehicle collision system. Various types of mechanism have been proposed to reduce force transmitted to the vehicle chassis and finally to protect occupants from injury. In the case of head-on collision, the bumper makes main role of isolation material for collision attenuation. In this study, the proposed bumper system consists of MR impact damper and structures. The MR impact damper utilizes MR fluid which has reversible properties with applied magnetic field. The MR fluid operates under flow mode. The bellows is used for generation of fluid flow. A mathematical model of the MR impact damper is derived incorporating with Bingham model of the MR fluid. Field dependent damping force is investigated with time and frequency domain. The MR impact damper is then incorporated with vehicle crash system. The governing equation of motion of vehicle model is formulated considering occupant model. Dynamic characteristics of vehicle collision system investigated with computer simulation.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.147-152
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• 2006

This paper presents the dynamic characteristics of MR impact damper for vehicle collision system. Various types of mechanism have been proposed for reduce transmitted force to vehicle chassis and finally protect occupants from injury. In the case of frontal collision, the bumper make main role of isolation material for collision attenuation. In this study, proposed bumper system composed of MR impact damper and structures. The MR impact damper is to adopted MR fluid which has reversible properties with applied magnetic field. MR fluid operates under flow mode with Bingham flow and bellows is used for generation of fluid flow. Mathematical model of MR impact damper incorporated with MR fluid is established. Field dependent damping force is investigated with time and frequency domain. The MR impact damper is then incorporated with vehicle crash system. The governing equation of motion of vehicle model is formulated considering occupant model. Dynamic characteristics of vehicle collision system investigated with computer simulation.

• 한국자동차공학회논문집
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• 제15권1호
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• pp.171-176
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• 2007

An important challenging issue in the automotive industry is the light-weight, safe design and enhancement of crash response of an auto-body structures. These objectives lead to increasing adoption of high strength steel sheet for inner and outer auto-body members. This paper evaluates the dynamic tensile characteristics of high strength steel sheets, HS45R, TRIP60, DP60 and DP100, along the rolling direction and transverse direction. Static tensile tests were carried out at the strain rate of 0.003/sec using the static tensile machine (Instron 5583). Dynamic tensile tests were carried out at the range of strain rate from 0.1/sec to 200/sec using a high speed material testing machine developed. The tensile tests acquire stress-strain relation and strain rate sensitivity of each material. The experimental results show two important aspects for high strength steels: the flow stress increases as strain rate increases; the strain hardening decreases as the tensile stress increases. The experiments also produce interesting results that the elongation does not decrease even when the strain rate increases.

• 대한교통학회지
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• 제34권1호
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• pp.29-42
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• 2016

과속은 교통안전에 있어서 중요한 영향요인이며, 사고 심각도에 영향을 끼칠 뿐만 아니라 사고 위험성과 밀접한 관련성이 있다. 본 연구는 청주시의 신호교차로에 설치된 36개 다기능단속카메라(신호 및 과속)에서 수집한 27,968건의 속도위반 자료에 대한 분석 결과를 제시하고 있다. 이 자료에는 위반자의 3년간 위반이력을 포함한 다양한 인구통계학적 특성들을 포함하고 있다. 따라서 본 연구의 목적은 속도위반과 인적, 차량 및 도로 환경요인들 간의 관련성을 알아보기 위함으로 분석방법은 통계프로그램 SPSS 20의 기술통계와 이항로지스틱 회귀분석을 이용하였다. 주요 연구 결과는 다음과 같다. 첫째, 속도위반은 지방부와 도시외곽부 지역에서 많이 일어났다. 둘째, 속도위반 운전자의 약 25.6%는 제한속도 대비 20km/h 이상의 심각한 수준의 과속운전을 한다. 셋째, 과속운전자와 정상속도 운전자에 영향을 주는 변수로는 교차로의 공간적 위치와 운전자의 성별 및 연령이 선정되었다. 마지막으로, 이항 로지스틱 회귀분석에 의해 통계적으로 유의한 모형이 개발되었다(Hosmer and Lemeshow test : 11.586, p-value: 0.171).

• 한국건설관리학회논문집
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• 제20권3호
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• pp.113-121
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• 2019

우리나라의 사망사고만인율은 주요 국가와 비교하면 2~3배 높으며 그 중 건설현장의 추락사고는 가장 많은 사망사고를 유발하고 있다. 기존연구와 국가기관의 조치를 살펴보면 추락사고에 집중된 산업재해 관리의 미흡과 계절별 안전관리 대책의 미비가 그 원인인 것으로 판단된다. 본 연구에서는 기존 연구 및 조치의 한계점을 해결하기 위하여 계절별 건설현장 추락사고 특징을 도출하고, 추락사고 방지책을 마련하는데 필요한 적정 정보를 제공하고자 한다. 정보의 제공을 위하여 사고발생 인과간계에 대하여 기술한 계절별 건설현장 추락사고 기사데이터 387건을 수집 후, 주성분분석과 군집분석을 활용한 텍스트 마이닝을 실시하였다. 분석결과 계절별 특징으로서 봄에는 강설, 리프트를 포함한 장비의 무리한 운용 등이 원인이며, 여름에는 거푸집, 점검미비, 설치작업 등이 원인으로 나타났다. 그리고 가을에는 바람과 태풍의 날씨요인 등이 원인이며 겨울에는 자재운반 및 외벽작업, 안전수칙 미 준수 등이 추락사고의 원인으로 나타났다.

• 한국실내디자인학회논문집
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• 제13호
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• pp.187-196
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• 1997

A Study on the Characteristics of the Modern Chair Design The features of the modern chair design results from the diverse life style unfolded as per the 20th century social structure and the change of the residential space, and new design has been being developed by the scientists and the artists in various fields through their cooperated work in a way. The field of the scientific or technical study and creation of arts can be developed where they can evoke the sympathy in the circumstances under which the various styles of both arts and science meet across, complement crash together, and grow up. The operation which can control in the network of such pluralistic sphere has been needed for a long period and it has been facing the needs from a time and society. The engineering furniture as the counterplan of the above has brought the value of materials into relief to the forms of human life by making the properties of matter the maximum value or changing it. It can be summarized as following characteristics in its materials and forms along as well as the 3 types (handycrafty, mechanical, and ecological expression) in process through the 20th century. 1. Characteristics in Materials elasticity of the chair as per the changes of the flexibility in the steel pipe development of systematic chair using the plasticity of the plywood, plastic, and wire lightweight due to the materials such as aluminum. 2. Formative characteristics formative simplicity for the increase of the function and the quality improvement such as sociality, productivity, environmental and aesthetic nature emphasis on the structure as per the architectural environment and tecniques pursuit of the forms as a container of the human body seeking for the formative values as the cultural symbols coping with the needs from thepluralistic social structure Furniture is not the makeup for convenience sake but most importantexpression as necessaries of our environments. It should identify itself always as per these kind of needs and also it should be able to used to keep the relation of such mutual division, otherwise the purchase of new furniture should be necessary according to every change of the existing situatiov. Our residence doesn't need the specific style but expresses only the properties of the dwellers.

• 한국사회복지학
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• 제39권
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• pp.210-237
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• 1999

이 연구는 IMF 이후의 대량실업 상황하에서 실업자의 실업탈피 가능성에 영향을 미치는 요인을 알아보고자 시도하였으며, 특히 정부의 실업대책이 실제로 실업자의 실업탈피 가능성에 어떤 영향을 미치는지를 실증적으로 알아보았다. 한국보건사회연구원과 한국노동연구원이 공동으로 실시한 '1998 실업실태 및 복지욕구조사' 자료에 대한 콕스 비례위험회귀(Cox Proportional Hazards Regression) 분석을 실시한 결과, 정부의 실업대책이 실업탈피 가능성에 미치는 영향은 분석대상의 실업탈피 유형에 따라 다르게 나타남을 발견하였다. 정부의 실업대책 이외에도 실업자와 실업가구의 인구, 사회 및 경제적 특성, 이전 직장관련 특성, 그리고 생계유지수단이 실업탈피 가능성에 미치는 영향을 분석하였으며, 연구결과를 바탕으로 보다 효과적인 실업대책을 마련하는 데 도움이 될 수 있는 정책방안을 제시하였다.

• 대한가정학회지
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• 제43권5호
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• pp.43-55
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• 2005

This research was designed to investigate and compare the characteristics of preferred clothing textiles for slacks and skirt of college students. One hundred five subjects majoring in fashion design were surveyed and the subjects selected three favorite materials among 120 samples presented in a swatch book. The subject's weighted frequencies were added tv order of preference. The results of this study were as follows: 1. In the spring and fall seasons, black twill cotton drill was preferred foremost as a textile for slacks, and medium gray basket weaved cotton pinhead with stripe pattern was preferred as a textile for skirts. 2. In summer, dark bluish gray plain linen crash was the most preferred material for slacks, and pale yellow plain linen tropical cloth was preferred for skirts. 3. In winter, olive gray cotton corduroy was the most favorite textile for slacks, and moderate brown twill wool hound check was preferred for the skirt. 4. In thickness and weight, textiles for winter were thicker and heavier than those chosen for other seasons, and textiles for skirts showed various thicknesses and weights as compared with those of slacks. 5. In fiber content, natural fibers such as cotton and wool were preferred for an seasons. 6. In the weave of textiles, twiu we,3ve was preferred for spring, fall and winter season, and plain weave was preferred for summer. 7 The most preferred colors for slacks were B and PB, and those for the skirts were YR and PB. For color characteristics, solid fabrics were generally preferred, and patterned fabrics were preferred for skirts as compared with slacks.

• 한국의류학회지
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• 제31권1호
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• pp.1-10
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• 2007

This research was designed to compare the subjective evaluation of Hand between on- and off-line by structure and sensible characteristics of fabric. 113 subjects who have a fashion design major evaluated the subjective evaluation of Hand of various 16 kinds of specimens on- and off-line. T-test and pearson correlation coefficient were used for statistical analysis by SPSS WIN 11.0. The results of this study were as follows: The results of correlation analysis of the evaluation score indicated that Crash and Satin show high correlation between two kinds of evaluation score. But, fabrics which have distinct characteristics such as Plush, Dobby, Seersucker represented low correlation coefficient. The results of t-test fer the difference of the evaluation score showed that thin fabrics like Organdy represent a large difference between on- and off-line evaluation. On the other hand, twill weaved fabrics like Drill, Tweed, Saxony did not show many differences. Analysing each item in terms of correlation of evaluation of hand between on- and off-line gave results that the shininess was most deliverable through on-line and density and the dryness was not so deliverable through on-line. Comparison of evaluation score between on- and off-line items showed that the estimation to real fabric is more negative than that of on-line. The results of most preferable hand between on-and off-line showed exact opposite preference between shinny, smooth and soft Satin and rough, woolen Tweed. Organdy showed the most different subjective evaluation of hand in real ones compared with that of on-line.

• International Journal of Concrete Structures and Materials
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• 제2권1호
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• pp.57-62
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• 2008

When the yield line theory is used to estimate the ultimate strength of a concrete barrier, it is of primary importance that the correct assumption is made for the failure mode of the barrier. In this study, a static test was performed on two full-scale concrete barrier specimens of Korean standard shape that simulate the actual behavior of a longitudinally continuous barrier. This was conducted in order to verify the failure mode presented in the AASHTO LRFD specification. The resulting shape of the yield lines differed from that presented in AASHTO when subjected to an equivalent crash load. Furthermore, the ultimate strengths of the specimens were lower than the theoretical prediction. The main causes of these differences can be attributed to the characteristics of the barrier shape and to a number of limitations associated with the classical yield line theory. Therefore, a revised failure mode with corresponding prediction equations of the strength were proposed based on the yield lines observed in the test. As a result, a strength that was more comparable to that of the test could be obtained. The proposed procedure can be used to establish more realistic test levels for barriers that have a similar shape.