• Title/Summary/Keyword: Rigidly fixed post

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Crashworthiness Study of Sliding Post Using Full Scale Crash Test Data (충돌실험 데이터를 이용한 슬라이딩 지주구조의 감충성능 분석)

  • Jang, Dae-Young;Lee, Sung-Soo;Kim, Kee-Dong;Sung, Jung-Gon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.40 no.1
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    • pp.1-11
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    • 2020
  • Medium to large post structures installed along the roadside without proper protection can lead to serious vehicle damage and occupant injury at the impact. In North America and Europe, splitting systems such as slip base or breakaway device are used to reduce impacts. But the system has the risk of secondary accident when the splitted post falls down to the traffic or pedestrian. Sliding Post have been proposed as a way to solve this problem. By studying the crash test results of the 1.3ton and 0.9ton vehicle with 60 km/h and 80 km/h to a Rigidly Fixed Post (RFP) and Sliding Post (SP), danger of the conventional RFP and crashworthiness of the SP have been proven. While collision analysis only from the acceleration measured at the center of the vehicle assumes the motion of the post is the same as that of the vehicle, in this paper, by adding high speed film data to the analysis with vehicle acceleration could have separate the post motion from the vehicle motion. It gives better explanations on the movement of post and vehicle in each distinctive time step and provides basics to the crashworthy post design.

The Effect of Interview with Scientist and Engineer on the Science Career Orientation and Image of Scientists (과학기술자와의 인터뷰가 과학 진로 지향 및 과학자 이미지에 미치는 영향)

  • Jeon, Hwa-Young;Lee, Jin-Myung;Hong, Hun-Gi
    • Journal of The Korean Association For Science Education
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    • v.28 no.4
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    • pp.350-358
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    • 2008
  • The purpose of this study was to investigate the effects of interview with a scientist and engineer on service performance assessment on science career orientation and image of scientists. Science track students in the 11th grade carried out the interviews and made powerpoint presentations. After the students' presentation in the chemistry class, the teacher made comments on the contents of the interviews. Students gave presentation in each class for a year. Before starting this assessment, students took science career orientation questionnaire and DAST (draw-a-scientist-test). These two tests were conducted again at the end of the year. The results of this study showed that there was no significant difference between pre- and post-test score for the science career orientation. However, a significant difference was observed in the 'preference for science learning' category. These results showed that the career decision of a high school student has already been fixed rigidly. On the other hand, there was a significant difference (p < 0.01) between pre- and post-test on the image of scientists. This demonstrated that the stereotypic image for a scientist was reduced by the interview performance assessment and that, students came to have an affirmative perception of scientists on service.