• Title/Summary/Keyword: Life History Method

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Fatigue Life Estimation Using the Multi-Axial Multi-Point Load Counting Method under Variable Amplitude Loading (가변진폭하중하에서 다축-다점 하중 Counting method를 이용한 피로수명평가)

  • Lee, W.S.;Lee, H.W.
    • Journal of the Korean Society for Precision Engineering
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    • v.14 no.6
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    • pp.22-27
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    • 1997
  • In general, the load which acts on the structure is almost independent of time in many locations. In this case. It is difficult to estimate the life with the service load history, because the structure is on the multi- axial and multi-point loading states. In this study, the service load of the excavator which is widely used in industry field was calculated using measured cylinder pressures and displacements. The fatigue life was estimated using the multi-axial and multi-point load counting method. Service load history of 4 pin joint which act independently each other is yielded by mult-axial and multi-point load counting method. The stress spectrum is yielded by superposition of the results of FEM stress analysis applied unit load. Palm- gren-Miner's cumulative Damage is 0.000804 for Von Mises equivalent stress sequence by one side fillet weld S-N curve. This result agress with Bench test results. As a result of this study, the fatigue life esti- mation using the multi-axial and multi-axial and multi-point load counting method is useful.

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Life History Traits and the Rate of Molecular Evolution in Galliformes (Aves)

  • Eo, Soo-Hyung
    • Journal of Ecology and Environment
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    • v.31 no.1
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    • pp.75-81
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    • 2008
  • Rates of molecular evolution are known to vary widely among taxonomic groups. A number of studies, examining various taxonomic groups, have indicated that body size is negatively and clutch size is positively correlated with the rates of nucleotide substitutions among vertebrate species. Generally, either smaller body mass or larger clutch size is associated with shorter generation times and higher metabolic rates. However, this generality is subject to ongoing debate, and large-scale comparative studies of species below the Order level are lacking. In this study, phylogenetically independent methods were used to test for relationships between rates of the mitochondrial cytochrome b evolution and a range of life history traits, such as body mass and clutch size in the Order Galliformes. This analysis included data from 67 species of Galliformes birds and 2 outgroup species in Anseriformes. In contrast to previous studies, taxa were limited to within-Order level, not to Class or higher. I found no evidence to support an effect of life history traits on the rate of molecular evolution within the Galliformes. These results suggest that such relationship may be too weak to be observed in comparisons of closely related species or may not be a general pattern that is applicable to all nucleotide sequences or all taxonomic groups.

A Study on the Prediction of the Fatigue Life of a Lug through the Finite Element Analysis (FEA를 이용한 Lug의 피로 수명 평가에 관한 연구)

  • 이원석;이현우
    • Journal of the Korean Society for Precision Engineering
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    • v.15 no.10
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    • pp.88-95
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    • 1998
  • The purpose of this study is to predict the life of a Lug under the real service load history. The techniques of predicting a fatigue life under load spectrum are discussed and some are developed. The stress is calculated by multiplying the stress under unit force with the Finite Element Analysis. The cycles are counted by the Rainflow counting method and then the mean stress effect is considered by the suggested conversion function. The Manson's Double Linear Damage Rule is used as the cummulative damage method.

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The Process Grandchildren's Growth: - Based on the Life History Approach - (조손가족 손자녀의 성장과정에 관한 생애사 연구)

  • Yoon, Ju Young;Koh, Bo Sun
    • Korean Journal of Family Social Work
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    • no.56
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    • pp.69-104
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    • 2017
  • This research aims to understand in depth and contextually of the grandchildren 's growth with their grandparents. The data were collected through in-depth interviews with observation and documents and analyzed using life history approach. The life history method was based on Mandelbaum(1973)'s framework including 'life dimensions', 'turning points', and 'adaptations'. After the analysis, central themes in each domain emerge as follows; 'social prejudice', 'growing poverty', 'a painstaking smile', 'more polite and honest', and 'being alone' in life dimensions, 'parentless children', 'a painful memory, outcast', and 'going to college' in turning points, and 'a willing person, parents', 'a blessed person', 'self-reliance and scale of economic life', and 'diligence and inborn cheerfulness' in adaptations, respectively. Based on these results, several intervention strategies and implications for healthy growth of grandchildren.

The change of Kitchen in a Single Detached House in Jeonju City after 70's through Oral Life History method (구술로 본 1970년대 이후 전주지역 단독주택 부엌의 변화)

  • Park, Sun-Hee
    • Journal of the Korean housing association
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    • v.17 no.6
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    • pp.55-63
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    • 2006
  • The purpose of this study is to investigate the change of kitchen in a single detached house in Jeonju city after 70's. Oral life history method which has 12 women's personal narratives and 17 women's personal narratives with written reports was used as a research method of this study. The results of the study were obtained as follows: 1) It was beginning about late 1970 year that heating system and cooking place were separated in a house. 2) Many kitchens were reconstructed for indoor stand-up work place from late 1970's to the early 1980's. 3) There were major factors such as heating system, cooking fuel, and work center in the change of kitchen in old houses. 4) The kitchen toward the center with a living room was appeared in the floor plan of modem house after 1990's. The symbolic words of the indoor kitchen that work for women were 'warmness' and 'convenience'.

A study of the creation mechanism of exclusion against the immigrant (이주민 배제 생성 기제에 대한 연구 -상층부 연구접근-)

  • Kim, Young Sook
    • Korean Journal of Social Welfare Studies
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    • v.44 no.2
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    • pp.5-33
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    • 2013
  • This study is to analyze the creation mechanism of exclusion and discrimination against the immigrant. The author approached studying up and used life history study method. Ten of anti-multiculturists participated this study. Data were collected by in-depth interview. The text of individual life history were analyzed by Mandelbaum(1973). The author analyzed the dimension of life, turning point and adaptation. The result as follows; I presented ① Plan of oneness ground, ② Searching new Sacrifice goat, ③ Transference of a inferiority complex for the mechanism of exclusion and discrimination against immigrant. Finally I proposed 「cross cultural education」, 「native participated integration program」, 「establishment of the strongpoint center for adjustment between native and immigrant and up bringing the professional in community.

A research on elementary school students with atopic dermatitis in Je-Cheon (제천 지역 소재 초등학교 학생들의 아토피 피부염에 대한 설문조사 연구)

  • Son, Son-Jung;Kim, Hee-Taek;Hong, Seung-Ug
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.22 no.2
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    • pp.163-175
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    • 2009
  • Objective : The aim of this study was to take a census of elementary school children who have atopic dermatitis(AD) especially the residents of Je-Cheon. Method : We conducted a questionnaire survey of the elementary school children in Je-Cheon who have atopic dermatitis. 96 patients with AD were involved in the survey. The questionnaire was made up of their family history, past history, weaning food, breast-fed or not, dietary treatment and Children's Dermatology Life Quality Index(CDLQI), etc. The student's T-test was used for statistical analysis. Results : Parents and siblings brothers and sisters past history has an effect on patients with AD. With regard to past history of patients, allergic rhinitis was the most common ailment. Formula feeding was common in the group under 6 months of age and the mean age of the start of weaning was 7.25 months. Fruit juice and weaning food of powder type were the first weaning foods in this study. Many parents introduced a grain diet, live diet, bone - soup, egg, milk, cheese and bean curd to their children under 12 months of age. A restricted diet was the most common dietary treatment method in this study. The highest scoring question for CDLQI was itching; the lowest one was related to bullying. Conclusion : We analyzed the patients' family history, past history, weaning food, dietary treatment and Children's Dermatology Life Quality Index(CDLQI), etc. Through this survey, we better understand the actual conditions of elementary school children who had AD in Je-Cheon.

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Interpretation of a Traditional Mansion, the Sunktyojang in Kangreung (상류(上流) 전통주거(傳統住居) 강릉(江陵) 선교장(船橋莊)의 해석(解釋))

  • Lee, Hee-Bong
    • Journal of architectural history
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    • v.8 no.4 s.21
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    • pp.39-62
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    • 1999
  • Basic concept of this study is that architectural form as a material at present has meaning for the dweller's life on the past historical plane. Main method to recover history is ethnographic interview to dwellers. Secondary method is to analyze ancestors' writings, buildings in the background of the family photos, and past drawings and then to relate them with architectural form at present. Taxonomy is a starting point: general name of the building by outside researcher is quite different from it by inside dwellers. 'Haengrang-chae', servant quarter, has never been used for servants. Function of the haengrang went outside thatched houses at the front village. Firsthand observation or simple analyses as results of several precedent research are reexamined and criticized through this study. The mansion has moaning when we synthesize with the site location based on farming land and tenant farmer, and decline of the Kyongpo Lake. Territoriality of the mansion is reinterpreted to 'In-Out Structure' by Yin-Yang thinking, Dwellers extend buildings gradually to outside village, surrounding rear hills, the lake, DongHae Sea, and finally goes to imaginative Taoist heaven beyond real nature through the literary life. Confucius principle, known to govern upper class house at Yi Dynasty also affect general composition of the buildings: perpetuation of the family by ancestor worship, elder dominance and male dominance, fraternity love in the extended family, charity display by reception of guests, Taoist scholarly life harmonized with nature. However, the study of the particular life and usage of the dwellers reinforces or corrects general supposition of precedent researches. Unique shape of the house has been formed by convenience of the dwellers' life style, early modernized free thought over the rigid Confucius design principle, and female power in male dominant society.

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Method using XFEM and SVR to predict the fatigue life of plate-like structures

  • Jiang, Zhansi;Xiang, Jiawei
    • Structural Engineering and Mechanics
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    • v.73 no.4
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    • pp.455-462
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    • 2020
  • The hybrid method using the extended finite element method (XFEM) and the forward Euler approach is widely employed to predict the fatigue life of plate structures. Due to the accuracy of the forward Euler approach is determined by a small step size, the performance of fatigue life prediction of the hybrid method is not agreeable. Instead the forward Euler approach, a prediction method using midpoint method and support vector regression (SVR) is presented to evaluate the stress intensity factors (SIFs) and the fatigue life. Firstly, the XFEM is employed to calculate the SIFs with given crack sizes. Then use the history of SIFs as a function of either number of fatigue life cycles or crack sizes within the current cycle to build a prediction model. Finally, according to the prediction model predict the SIFs at different crack sizes or different cycles. Three numerical cases composed by a homogeneous plate with edge crack, a composite plate with edge crack and center crack are introduced to verify the performance of the proposed method. The results show that the proposed method enables large step sizes without sacrificing accuracy. The method is expected to predict the fatigue life of complex structures.

Analysis of a Dynamic Rig Test Model for Truck Chassis Systems (트럭 샤시 시스템의 동적 리그시험모텔 해석)

  • 임재혁;성현수;임세영
    • Transactions of the Korean Society of Automotive Engineers
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    • v.12 no.4
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    • pp.94-100
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    • 2004
  • A dynamic finite element analysis of a rig test model for truck chassis systems is conducted to establish an appropriate model designed to predict the fatigue life. A reference Belgian road input, which has been obtained from a field test, is imposed on the finite element model in the modal finite element analysis, and the resulting strain history is employed for the prediction of the fatigue life. This is compared with the prediction based upon the strain history measured in the field test. The two agree with each other within the limitation of the field data and the input data to the model. The high frequency responses over 50 Hz are confirmed to be negligible as far as their effect on the fatigue life is concerned.