• Title/Summary/Keyword: life-history

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A Study on the Estimation of the Fatigue Life Using the Stress Generated Models in the Steel Railroad Bridges (강철도교의 응력발생모형을 이용한 피로수명 추정에 관한 연구)

  • Yong, Hwan Sun;Kim, Seok Tae;Lee, Seong Soo
    • Journal of Korean Society of Steel Construction
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    • v.8 no.4 s.29
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    • pp.19-29
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    • 1996
  • In this paper, it is presumed that the stress time history was generated by simulation method and investigated compatibility in regard to the reappearance of stress time history. In this procedure, the identified frequency distribution of stress range of the steel railroad bridge varies with the rational values of cut off point and bar width. Thus, we show variable aspect of the equivalent stress range results from change of cut off point and bar width. In addition, we analyze the variable of RMC and RMS model due to the cut off point and bar width of the measured stress history which influencs the prediction of fatigue life in the steel railroad bridge. The simulated stress time history is carried out by the superposition method incorporating the vertical load with rotation moment obtained from the Hermition interpolation function, and compared with developing stress results from measured maxi mum stress. Through this study, we can estimate the remaining fatigue life from a safety point of view and comparative accuracy.

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Goniotrichopsis reniformis (Kajimura) Kikuchi comb. nov. (Stylonematales, Rhodophyta) from Japan

  • Kikuchi, Norio;West, John A.;Kajimura, Mitsuo;Shin, Jong-Ahm
    • ALGAE
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    • v.21 no.2
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    • pp.185-191
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    • 2006
  • The morphology and life history of Stylonema reniforme Kajimura (Stylonematales, Rhodophyta) from Japan were investigated and its taxonomic placement was discussed. This species has 6-30 discoid chloroplasts devoid of a pyrenoid in each cell. This is a typical feature of the genus Goniotrichopsis. The species reproduced only by monospores, which were formed by the direct transformation of the vegetative cells similar to the type species Goniotrichopsis sublittoralis Smith. Goniotrichopsis reniformis (Kajimura) Kikuchi comb. nov. was proposed. The asexual life history of the present species was completed in 3-10 weeks at $15-20^{\circ}C$ in culture.

Thermal Fatigue Life Prediction of Alumina by Finite Difference Model (유한 차분 모델을 이용한 알루미나의 열피로 수명 예측)

  • 이홍림;한봉석
    • Journal of the Korean Ceramic Society
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    • v.30 no.3
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    • pp.229-235
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    • 1993
  • Thermal history and thermal stress of alumina specimen, which occured from thermal shock process, were calculated by finite difference method. Stress intensity factor and crack growth in cyclic thermal fatigue were calculated from single thermal shock temperature history and thermal stress. Cyclic thermal life were estimated by bending strength after cyclic thermal shock under critical thermal shock temperature. Calculated stress intensity factor was compared with real experimental thermal fatigue life of specimen. Fatigue life until critical stress intensity factor and real experimental result were comparable.

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A Study on the Meaning and Scalability of Citizens' Oral History Archiving: Focusing on the Ministry of Culture, Sports and Tourism's 'Digital Life History Archiving Project' in 2021 (시민 구술 아카이빙의 의미와 확장성 고찰 2021년 문화체육관광부 디지털생활사아카이빙 사업을 중심으로)

  • Sohn, DongYou
    • The Korean Journal of Archival Studies
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    • no.80
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    • pp.129-165
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    • 2024
  • This study aims to emphasize the importance and activation of citizen oral history. As is well known, research on oral history gradually began in earnest in Korea from the 1980s. Until now, citizen interviews by researchers and elite interviews by researchers have steadily increased in quantity. However, citizen interviews by citizens are insignificant. The "Digital Life-history Archiving" project, which has been under the supervision of the Ministry of Culture, Sports and Tourism since 2021, is a new and meaningful attempt. Citizens are educated on archiving and oral history to conduct interviews and produce archives. It is producing high-quality oral archives, securing citizens' archiving capabilities, and building local cultural resources. Based on the experience of participating in this project in 2021, I evaluated the performance and limitations and looked at the implications. I expect it to help reduce trial and error in the future. I also proposed a plan to actively produce and utilize citizen oral archives. To this end, specific cooperation between oral-history institutions and oral archives platforms were also proposed.

셀룰러 오토마타 상에서 자기 복제

  • 위규범
    • Journal for History of Mathematics
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    • v.12 no.1
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    • pp.73-81
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    • 1999
  • We survey the researches on self-reproducing structures on cellular automata. Self-reproduction is the foremost characteristic of life, and cellular automata are ideal model for studying artificial life. From the early studies by Von Neumann to late results on computational models using self-reproducing structures and emergence of self-replication are covered. Also possible applications of self-replicating structures are listed.

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Life History, Ginseng Damage and Chemical Control of the Snail Acusta despecta sieboldiana (명주달팽이의 생활사, 인삼의 피해 및 약제 방제)

  • 김기황
    • Journal of Ginseng Research
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    • v.16 no.2
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    • pp.146-150
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    • 1992
  • Life history, ginseng damage, and chemical control of the snail Acusta despecta sieboldiana Pfeiffer were investigated in the field and laboratory conditions from 1987 to 1990. Eggs of the snail were whitish globular and 1.,93${\pm}$ 0.09 mm in diameter which were deposited as egg mass composed of 28.4${\pm}$ 15.4 eggs. Egg period was 11.8${\pm}$ 1.6 days under the laboratory condition. Most eggs were laid during mid July in the field. The snail had a life cycle of a year and hibernated from November to April. Significant ginseng damages by the snail (over 10% to the total number of plants) were observed only in the three to five year old ginseng fields with rice straw mulching. Based on the dates that the first ginseng damages were observed and on the questionary examination, ginseng damages seemed to occur from May to July. Metaldehyde (6%) bait showed reliable control effects on the snail.

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A STUDY ON THE FATIGUE LIFE PREDICTION OF GUIDEWAY VEHICLE COMPONENTS (안내궤도 차량 부품의 피로 수명 예측에 관한 연구)

  • Lee, Soo-Ho;Park, Tae-Won;Yoon, Ji-Won;Jeon, Yong-Ho;Jung, Sung-Pil;Park, Joong-kyung
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.997-1002
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    • 2007
  • A guideway vehicle is used in automobile, semiconductor and LCD manufacturing industries to transport products efficiently. Since the operating speed of the guideway vehicle should be increased for maximum productivity, the weight of the vehicle has to be reduced. This may cause parts in the system to fail before the life of the system. Therefore estimation of the fatigue life of the parts becomes an important problem. In this study, the fatigue life of the driving wheel in the guideway vehicle is estimated using a S-N curve. To obtain the fatigue life of a part, the S-N curve, load time history applied on a driving wheel and material property are required. The S-N curve of the driving wheel is obtained using the fatigue experiment on wheels. Load time history of the wheel is obtained from multibody dynamics analysis. To obtain the material properties of the driving wheel, which is composed of aluminum with urethane coating, a compression hardware testing has been done with the static analysis of the FE model. The fatigue life prediction using computational analysis model guarantees the safety of the vehicle at the design stage of the product.

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A study on the life history of Women with Mental disorders who Experienced divorce (이혼을 경험한 여성정신장애자의 생애사 연구)

  • Mi-yeon Hong
    • Journal of the Health Care and Life Science
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    • v.9 no.2
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    • pp.317-326
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    • 2021
  • The purpose of this study is to understand more deeply the life of a woman with mental disabilities who experienced divorce through oral data analysis and to derive a therapeutic plan. Women with mental disorders diagnosed with depression and panic disorder participated in the study, and the text for life history analysis consisted of oral data interviews. Based on the life history analysis framework proposed by Mandelbaum (1973), the text was analyzed into three conceptual frameworks: 'Dimensions', 'Turning point', and 'Adaptation'. As a result of data analysis, the 'Dimensions' was analyzed as "Abandoned child", "The onset of mental illness", "Religion", and "Crime". In the 'Turning point' analysis, "Divorce" and "Life separation" were analyzed, and "Adaptation" was derived as "Rationalization". Based on the results of this study, a therapeutic intervention plan was proposed for the life of a female mentally disabled woman who has experienced divorce.

History as an Educational Tool: The Educational Turn of the Bakken Museum

  • Shin, Jieun
    • International Journal of Advanced Culture Technology
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    • v.9 no.4
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    • pp.71-85
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    • 2021
  • The history of the Bakken Museum, the Museum of Electricity in Life, is useful to understand the universality and particularity of a local science museum. Beginning with the small collections at the medical device company, the Bakken Museum has expanded its scope and facilities by reidentifying its mission from research institute to educational center. The educational turn of the Bakken Museum has been completed with two remarkable events: the launch of the Summer Institute in 1984 and the construction of the new education facility, New Wing, in 1999. During this change, the museum staff developed unique strategies for public engagement, using the history of science and technology as an educational tool. The shift of the Bakken Museum's mission provides an excellent example of how a local museum could meet the social needs for museums to be educational centers by utilizing its history and collections.

Fuel Consumption Prediction and Life Cycle History Management System Using Historical Data of Agricultural Machinery

  • Jung Seung Lee;Soo Kyung Kim
    • Journal of Information Technology Applications and Management
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    • v.29 no.5
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    • pp.27-37
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    • 2022
  • This study intends to link agricultural machine history data with related organizations or collect them through IoT sensors, receive input from agricultural machine users and managers, and analyze them through AI algorithms. Through this, the goal is to track and manage the history data throughout all stages of production, purchase, operation, and disposal of agricultural machinery. First, LSTM (Long Short-Term Memory) is used to estimate oil consumption and recommend maintenance from historical data of agricultural machines such as tractors and combines, and C-LSTM (Convolution Long Short-Term Memory) is used to diagnose and determine failures. Memory) to build a deep learning algorithm. Second, in order to collect historical data of agricultural machinery, IoT sensors including GPS module, gyro sensor, acceleration sensor, and temperature and humidity sensor are attached to agricultural machinery to automatically collect data. Third, event-type data such as agricultural machine production, purchase, and disposal are automatically collected from related organizations to design an interface that can integrate the entire life cycle history data and collect data through this.