• Title/Summary/Keyword: life history

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피로 및 진동에 의한 자동차 추진축의 내구성 연구 (A Study on Durability of Automotive Propeller Shaft by Fatigue and Vibration)

  • 조재웅;김세환;김기선
    • 한국산학기술학회논문지
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    • 제12권4호
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    • pp.1495-1501
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    • 2011
  • 본 연구는 동력전달 장치인 추진축이 차량 주행중 상하운동에 따라 생기는 자재이음의 내구성에 대한 강도 해석을 하였다. 유니버설 조인트에서의 최대 등가 응력과 전변형량은 요크 부분에서 $1.3177{\times}10^3$Pa및 $3.6148{\times}10^{-4}$m로 크게 나타났다. 'SAE bracket', 'SAE transmission' 및 Sample history'의 불규칙 피로 하중들 중에서는 하중의 변화가 극심한 SAE bracket'의 경우가 사용 가능 수명이 15951 Cycle 정도로 가장 짧은 것을 볼 수가 있고 하중의 변화가 가장 완만한 Sample history'에서 사용가능 수명이 $2{\times}10^7$ Cycle 정도로 가장 긴 것을 알 수 있었다. 피로 하중의 빈도수로서는 SAE Bracket history'가 80% 정도로서 가장 높게 나타나 파손의 가능성이 큼을 알 수 있었고 Sample history'가 5%로서 가장 낮게 나타났다. 그리고 구속 조건을 가하여 한 Harmonic response 해석에서의 최대 변위는 58Hz에서 일어났다. 이러한 진동수에서의 최대 변위는 0.00261m가 되었다. 본 연구의 결과를 종합하여 동력전달 장치인 추진축에 응용한다면 그 파손 방지 및 내구성을 예측하는데 활용이 클 것으로 사료된다.

교원 은퇴자의 삶의 여정에 관한 생애사 연구 (The Life History Study on the Life Journey of Retired Teachers)

  • 박종환;윤선숙
    • 한국콘텐츠학회논문지
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    • 제21권1호
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    • pp.626-638
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    • 2021
  • 본 연구는 생애사 연구로서 교직에서 은퇴한 유·초·중등의 남·여 교원의 삶을 통하여 은퇴의 의미와 적응과정을 탐색하여 교원 은퇴자들에게 개인적·사회적 필요가 무엇일지 알아보고자 하였다. 연구 결과, 어린 시절의 성장 경험과 학창 시절의 경험은 학생에게 선한 영향을 주거나 하지 말아야 할 행위의 한계를 설정하는데 기여하는 등, 오롯이 본인의 직업 수행에 영향을 준 것을 알 수 있었다. 상호의존의 시기에 단순 직업인을 넘어서 사회와 국가에 봉사하는 데에 기여하였고, 교직 후반기에는 아픈 경험이 자원이었고 '생각을 바꾸니 세상이 바뀌었다'는 표현으로 깨달음을 얻었다고 하였다. 교원이 미치는 행위의 영향이 다른 직업과 달리 다수의 대상에게 미친다는 점에서 교원 은퇴자들에게는 은퇴 전의 직업에 대한 보람이나 만족감이 다른 직종과 대비될 정도로 컸다. 그러나 은퇴 후에 교원 은퇴자들은 무한 자유에 행복을 느끼면서도 소속감과 성취감 없는 삶에 심리적인 공허함을 느꼈다. 그리고 새로운 공부에 도전하며 삶의 이모작을 위한 끊임없는 전진을 하고 있었다.

신장도(腎臟圖)의 형태요소와 그 변이(變異)에 대한 연구 (Factors of Variation in Diagrams and Location of Kidney)

  • 조학준
    • 한국의사학회지
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    • 제31권1호
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    • pp.23-42
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    • 2018
  • This study examines the variation in diagrams of the kidney, and the effects on location of the Life Gate as a result. My study analyzes diagrams of kidney form and location, such as appearance, the vertebral spine, ShenXi, and "Life Gate", and also explores the causes for such variations. The kidney is commonly described as having the shape of a bean, which throughout medical history has showed almost no variation. The spine was initially described with a total of 21 vertebrae, and later with a range of 19-25 vertebrae. Regarding the height of kidney in relationship to the spine, it was initially described as beginning at the 14th vertebrae, and later changed to the 15th or 17th vertebrae. However, there have been no changes in the perception of the height of kidney. Initially, the location of the Life Gate could not be identified. Three different suggestions of its location were found throughout historical literature, including: (1) at or within the right kidney; (2) between two kidneys; and (3) between 14th-15th spine. There were also variations noted in the process of copying diagrams of kidney in many books not only because the work of copying was not precise, but also because each medical practitioner had a different interpretation of the kidney's form and function in Traditional Korean and Chinese Medicine. It appears that some practitioners may have been influenced by their understandings of theory of Life Gate.

한국 여성 유방암의 위험요인 분석 (A Study on the Risk Factors for Breast Cancer in Korean Women)

  • 윤귀옥;박형숙
    • 기본간호학회지
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    • 제8권1호
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    • pp.7-23
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    • 2001
  • This study was done to provide basic data on prevention of breast cancer by identifying and analyzing risk factors for breast cancer in Korean women. The data were collected from three hospitals. The data from Jan. 1995 to Dec. 1997 was based on the patient recordings and personal contacts if possible. Data from 1998 to 1999 was collected from 280 inpatients and outpatients diagnosed as breast cancer. From this data, information about the risk factors of breast cancer could be acquired. The factors are scaled according to the degree of risk. Menstrual history, obstetrical history, family history. lactation period, life style were given 5 point, and body mass index was given 4 point. Using one-way ANOVA. the most important risk factors were identified and analyzed by multiple regression. The conclusion of this study are as follows : General factors which would show an effect on the results of the multiple regression included risk factors such as menstrual history, obstetrical history, lactation period, family history, and life style factors including mortal state, monthly income, educational level, job and age. Family history(R=0.481) was found to be the highest risk factor(23.1%) affecting breast cancer risk. The next factors were dying hair(R=0.603), drinking(R=0.846), body mass index(R=0.885), smoking(R=0.916), age of menopause(R=0.937), pregnancy age of first full-term(R=0.957), eating vegetable(R=0.980) and the number of full term pregnancies in that order. The sum total(R=0.986) of all the above factors accounted for 97.3% of the risk of breast cancer for Korean women. In conclusion, it was found that family history and dyeing hair were the highest risk factors for breast cancer. It is recommended that those with a family history of breast cancer should have regular breast examinations, and those who often dye their hair should reconsider this practice.

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A Phylogenetic Analysis for Hox Linked Gene Families of Vertebrates

  • Kim, Sun-Woo;Jung, Gi-La;Lee, Jae-Hyoun;Park, Ha-Young;Kim, Chang-Bae
    • Animal cells and systems
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    • 제12권4호
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    • pp.261-267
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    • 2008
  • The human chromosomes 2, 7, 12 and 17 show genomic homology around Hox gene clusters, is taken as evidence that these paralogous gene families might have arisen from a ancestral chromosomal segment through genome duplication events. We have examined protein data from vertebrate and invertebrate genomes to analyze the phylogenetic history of multi-gene families with three or more of their representatives linked to human Hox clusters. Topology comparison based upon statistical significance and information of chromosome location for these genes examined have revealed many of linked genes coduplicated with Hox gene clusters. Most linked genes to Hox clusters share the same evolutionary history and are duplicated in concert with each other. We conclude that gene families linked to Hox clusters may be suggestion of ancient genome duplications.

동양수학사에서의 조선수학의 역할과 의미 (The Role and Meaning of Joseon Mathematics in the History of Asian Mathematics)

  • 이상욱
    • 한국수학사학회지
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    • 제31권4호
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    • pp.169-181
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    • 2018
  • We here discuss about the roles and meaning of Joseon mathematics in the history of Asian mathematics from cultural perspective. To do so, we focus on culture. We first look at the meanings and the definitions of the terms, civilization and culture, and their differences. We next discuss on the cultural perspective to look at the mathematical history of Korea, which is considered as a part of the history of Asian mathematics. It is notable that Joseon mathematics of Korea made Asian mathematics develop further, and played the roles of academic bridges among China, Korea and Japan. It also kept and prolonged the life of the Asian mathematics up to the beginning of the 20th century.

Developmental Characteristics and Life History of the Korean Native Firefly, Pyrocoelia rufa

  • Kim, Jong-Gill;Kim, Keun-Young;Park, Young-Cheol;Park, Ji-Young;Kim, Sam-Eun;Jin, Byung-Rae;Lee, Sang-Mong;Lee, Jong-Eun;Lee, Ki-Yeol
    • International Journal of Industrial Entomology and Biomaterials
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    • 제6권1호
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    • pp.69-72
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    • 2003
  • Development and life history of the Korean native firefly, Pyrocoelia rufa, were investigated throughout the indoor rearing. Average size of egg with an oval shape was 1.7 m and the hatchability of egg of P. rufa was approximately 88.5%. The larvae were pupated at the ${5^th}$ instar and the body length of the matured larvae was 27.1 mm. The total periods of larval stage to the end of the 5$^{th}$ instar were approximately 104.7 days. Average pupal period was 10.3 days and average number of eggs oviposited by a female was 87.3 eggs. The body size of female in the pupa and adult was larger than that of male. The wings of female adult were deteriorated.

사할린 영주귀국 동포의 주거생활사: 안산시 고향마을 거주 강제이주 동포를 중심으로 (Housing History of Sakhalin Returnees in Ansan Gohyangmaeul)

  • 조재순
    • 한국주거학회:학술대회논문집
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    • 한국주거학회 2009년 춘계학술발표대회 논문집
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    • pp.294-299
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    • 2009
  • The purpose of this research was to find out the housing history of Sakhalin returnees since leaving hometown under the Japanese ruling period. Face to face interview had been done with 20 returnees in the community center during October to December, 2008. Personal life as well as housing histories were differed by the reason to move into Sakhalin, which still influenced the returnee' life in Ansan. The housing they had lived changed from barracks like a training camp, to Japanese small wooden cottage/row house, and then Russian brick house/apartment. Housing alteration and addition were common to renew the old house. The boundary of residing area was mostly limited to the first residing location throughout one's life without a long distance move. Housing satisfaction was very high in Gohyangmaeul because of the improvement of housing facilities and residence itself as well as convenience of housing management compared to the residence in Sakhalin. Economic and emotional aspect of life satisfaction were also high through about 8 years of living in. Forced movers still require the compensation on hand no matter the amount.

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Developmental Characteristics and Life History of the Korean Native Fire-fly, Luciola lateralis

  • Kim, Jong-Gill;Kim, Sam-Eun;Park, Ji-Young;Yoon, Hyung-Joo;Park, Young-Cheol;Ohba Nobuyoshi;Jin, Byung-Rae;Noh, Si-Kap
    • International Journal of Industrial Entomology and Biomaterials
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    • 제3권2호
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    • pp.141-147
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    • 2001
  • To study the ecological characteristics of the Korean native firefly, Luciola lateralis, development and life history of L. lateralis were investigated throughout the indoor rearing. Average size of egg with an oval shape was 0.51${\times}$0.56 mm and an egg period of L. tateralis was approximately 25.8 days. The larvae were pupated at the 5$^{th}$ instar and the body length of the matured larvae was 15.8mm. The total periods of larval stage to the end of the $5^{th}$ instar were approximately 271.7 days. Pupae formed soil cocoon and average pupal period was approximately 28.7 days. Average number of eggs oviposited by a female was approximately 97. The body size of female in the pupa and adult were larger that of male.

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