• Title/Summary/Keyword: 疲勞

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Critical Aspect of Non-Propagation of Short Fatigue Crack in Structural Steel (구조용 강재에 발생하는 미소피로 크랙의 정유요인)

  • 김민건
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.15 no.3
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    • pp.880-886
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    • 1991
  • 본 연구에서는 이미 크랙전파의 제단계에 있는 평골재의 정유 크랙을 대상으 로, COD를 고정밀도로 측정하는 것을 주된 수단으로하여, 피로한도의 존재유무를 지배 하는 미소크랙의 정유구조를 상세히 밝히고자 한다. 또한 변형시교에 근거한 현상으 로만 알려져온 과소응력효과, coaxing효과를 크랙폐구현상의 관점에서 검토하여, 크랙 정유현상의 본질적인 이해를 얻고자 한다.

Comparison of Respiratory Symptom between Urban and Rural Residents (도시주민(都市住民)과 농촌주민(農村住民)의 호흡기증상(呼吸器症狀))

  • Yoon, Jung-Suk;Kim, Doo-Hie
    • Journal of Preventive Medicine and Public Health
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    • v.18 no.1
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    • pp.113-127
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    • 1985
  • This paper was carried out for comparison of respiratory symptoms between urban and rural residents that is somewhat related to air pollution. And as urban residents, 470 persons of Daegu (Taegu) and 364 of Pohang were selected and 472 rural residents were also, in Eusong-Gun, those who were responded to questionnaire distributed from April 10, 1984 to April 30 through students of middle or high school. The subjects were families of the student. The questionnaire was appropriately modified the item B of Cornell Medical Index by author. Looking into the rate of complaints about each part, generally, the rate in urban is higher than that in rural. Particulary it is higher to 'feeling a choking lump or swelling of throat', 'the sputum' and 'the asthma' in the city (p<0.05). On the contrary, women in the farm village, to 'caught a severe cold' as compared with the city. In men under nineteen yearn of age, it is higher than the farm village to 'feeling a choking lump or swelling of throat' of Pohang (p<0.05). But in men forties, it is higher than the city that farm people are 'soaking sweat at night' and 'foreign body sensation on throat'. Students hardly differ between the two areas, while the group having occupation in Pohang felt more in 'feeling a choking lump or swelling of throat' than the farm residents. As the result, I consider that the rural residents were much affected by physical fatigue and pestisides, and the urban, by some problems of industrial fuel, traffic gas and various dusts.

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