• Title/Summary/Keyword: life history

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Egg Development and Early Life History of Korean Endemic Species Korean Spotted Sleeper, Odontobutis interrupta (Pisces: Odontobutidae)

  • Park, Jae-Min;Han, Kyeong-Ho;Kim, Na-Ri;Yoo, Dong-Jae;Yun, Seong-Min;Han, Ji-Hyeong
    • Development and Reproduction
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    • v.18 no.4
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    • pp.259-266
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    • 2014
  • The egg development and early life history of Korean spotted sleeper, Odontobutis interrupta which is Korean endemic species from Sora-choen was investigated. The Korean spotted sleeper were caught at Sora-myeon, Yeosu-si, Jeollanamdo, from Korea at May in 2014. The fertilized eggs were $4.23{\pm}0.05mm$ in long diameter and had oil globules. Hatching time of the embryo began about 442 hr 14 min after fertilization under water temperature of $19.5^{\circ}C$. The newly hatched larvae were $4.27{\pm}0.35mm$ in total length and their anus were not yet opened. 3 days after hatching postlarvae was measured $6.20{\pm}0.11mm$ in total length. 10 days after hatching postlarvae was measured $6.69{\pm}0.14mm$ in total length.

Development of Eggs and Early Life History of Korean Bitterling, Rhodeus pseudosericeus (Acheilognathinae) (한강납줄개, Rhodeus pseudosericeus (Acheilognathinae)의 난 발생과 초기생활사)

  • Kim, Chi-Hong;Kang, Eon-Jong;Kim, Jong-Hwa
    • Korean Journal of Ichthyology
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    • v.18 no.3
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    • pp.266-272
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    • 2006
  • The egg development and early life history of Korean endemic bitterling Rhodeus pseudosericeus were observed under the controlled water temperature, $17.0{\pm}0.5^{\circ}C$. Fertilized eggs are opaque yellow in color, measuring 2.9~3.1 mm in length and 1.6~1.9 mm in breadth. The eggs of this species began to hatch about seventy hours after insemination and the range of total length of larvae were 3.2~3.4 mm. The larvae reached at the heterotrophic stage about twenty-five days after hatching. R. pseudosericeus had a pair of wing-shaped yolk projection during the prelarval stage that is a common character of the genus Rhodeus.

A Study on Fatigue Durability through the Structural Analysis of Strut Bar (스트럿 바의 구조 해석을 통한 피로 내구성에 관한 연구)

  • Han, Moonsik;Cho, Jaeung
    • Transactions of the Korean Society of Automotive Engineers
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    • v.24 no.5
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    • pp.504-511
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    • 2016
  • This study investigates the durability of strut bar at car through structural and fatigue analyses. In this study, there are model 1 and model 2 as the analysis subjects. Model 1 is the existed one and model 2 is the improved one added with the reinforced part. Model 1 has the maximum equivalent stress of 165.11 MPa shown intensively at the welding part between the bracket and the bar. This stress is distributed over at the part of model 2 reinforced with this part. In case of fatigue analysis, there are three kinds of fatigue load as SAE bracket history, SAE transmission and sample history. The maximum fatigue life at SAE bracket history among three kinds of fatigue loads has the least value of $3.3693{\times}10^5$ cycles. The maximum fatigue life of model 2 becomes longer than that of model 1. As model 2 has the fatigue damage less than model 1, model 2 has the safety than model 1. As the fatigue durability about the configuration of strut bar is analyzed, it is thought to apply this study result into the real part effectively.

Early Life History Characteristics of an Induced Hybrid between Rhodeus uyekii and Rhodeus ocellatus (각시붕어(Rhodeus uyekii)와 흰줄납줄개(Rhodeus ocellatus) 잡종의 초기생활사 특징)

  • Park, Jae-Min;Han, Kyeong-Ho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.52 no.4
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    • pp.408-417
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    • 2019
  • This study was conducted to identify taxonomic differences in the characteristics of Rhodeus uyekii and Rhodeus ocellatus during their initial life history via an interspecific hybridization experiment. Hybrids were compared to their parent species, and the findings were used to inform developmental research in commercially useful aquarium fish. The hatching rates of the cross-bred eggs were 75.9% for cross UO (R. uyekii ♀${\times}$R. ocellatus♂) and 71.9% for cross OU (R. ocellatus♀${\times}$R. uyekii♂), which did not differ greatly from the hatching rates of the normal cross-bred group. Backcross experiments resulted in 100% egg mortality during development. Newly hatched larvae of the original hybrid crosses were similar to those of the maternal line, and the color of the egg yolk was similar to that of the paternal line; therefore, the respective traits of the interspecific parents were identifiable within the cross-bred offspring.

Early Life History of Lefua costata (Cypriniformes : Balitoridae) from Korea

  • Park, Jae-Min;Cho, Seong-Jang;Han, Kyeong-Ho
    • Development and Reproduction
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    • v.24 no.4
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    • pp.307-316
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    • 2020
  • The purpose of this study is to observe the early life history of Korean Lefua costata and use the result as basic taxonomic research data for balitorid fish. The fertilized eggs were light green color with completely circle shape and mean size was 1.21±0.06 mm (n=30). Immediately after hatching, the size of the larvae was 2.81±0.11 mm (n=5) in mean length, with egg yolk. On the 3rd day after hatching, the preflexion larvae had a mean length of 4.64±0.09 mm (n=5), and their mouth was opened to start feeding. On the 8th day after hatching, a mean length of the postflexion larvae was 9.43±0.46 mm (n=5), the distal part of the notochord was bent to 45°, and 16 fin rays were developed on the caudal fin. On the 31st day after hatching, a mean length of juveniles was 22.3±0.85 mm (n=5), and the number of fin rays was the same as that of adult fish with (iv8) dorsal fins and (iii8) anal fins.

A Study on the 'Closed ㄱㄴ Type' of Traditional Folk Housing in Goyang, Gyonggi-do, Focused to Dweller's Life (거주자 생활중심으로 본 경기 고양 전통민가 연구 - 폐쇄형 ㄱㄴ자집을 중심으로 -)

  • Lee, Hee-Bong
    • Journal of architectural history
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    • v.14 no.3 s.43
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    • pp.53-76
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    • 2005
  • Through a field study of the folk houses, 'Closed ㄱㄴ Type' in Goyang-si, Gyonggj-do, focused on the dweller's life by the method of ethnographic interview, observation, and physical survey. L and opposite L type of inner and outer buildings form a closed inner court, and innermost backyard for woman is enclosed by fence. Form and space of the house contains dweller's traditional life. Outer space of a front gate becomes semiprivate space, for thrashing and piling up harvest and raising vegetables and pigs. Confucius principle does not fully dominate dweller's life of ancestral rite at Daecheong floor, and separation of man's and woman's quarter. Superstitious worship activities took place for lord of site and house. In everyday life, Anbang, inner main room, is assigned for parent's quarter instead of woman's quarter, and Geornbang, next room, was for son's family. Anbang has symbolic meaning for a place of deathbed. House contains agricultural activities, crop harvesting, thrashing, putting into storage, hulling rice, and keeping grain near kitchen. At present, rooms are needed more; sheds are made into rooms, rooms are enlarged toward outside, half outside space like Daechong floor becomes interior space by sash screen. And modern facilities of kitchen and bathroom are equipped for convenience. At the end, meaning and generative principle of those forms are discovered.

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Development of Integrated Fatigue Strength Assessment System (피로강도평가를 위한 통합 전산 시스템의 개발)

  • Park, Jun-Hyeop;Song, Ji-Ho
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.2
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    • pp.264-274
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    • 2001
  • An integrated fatigue strength assessment system was computerized. The system developed consists of 9 modules: user interface, cycle counting, load history construction, data searching, fatigue properties estimation, fatigue data analysis, true stress and strain analysis, expert system for crack initiation life prediction, fatigue crack initiation and propagation life prediction. Fatigue strength database also was included in this system. The fatigue expert system helps a beginner to predict a fatigue crack initiation life in fatigue strength assessment. The expert system module in this system is developed on the personal computer by using C language and UNiK, an expert system developing tool. To evaluate the system, the results of test under variable loading of SAE and failure data from a field were analyzed. The evaluation show that the system provided fatigue life prediction within 3-scatter band and gave reasonable predictions. To get more accurate predictions of fatigue life without fatigue properties, we recommend utilizing the system along with the fatigue strength database.

Toward the Cultural Approach to the Discipline of Korean Design History: -A Plea for the Domestic Handcrafts of Yang, Gap-Jo- (한국디자인사 연구의 문화사적 접근을 향하여 -양갑조 할머니의 규방 공예품을 위한 변론-)

  • Ko, Young-Lan
    • Archives of design research
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    • v.17 no.4
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    • pp.375-384
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    • 2004
  • The general tendency of approach to Korean Design History has been focusing its primary interest on the grand story in relation to the problems of modernization in political, economical and social aspects of Korea. In the discourse of modernization, however, there are two sides immanent in the modernization: there is the formal, institutional and authoritative modernization developed inside the capitalistic mode of production and the informal, individual and cultural modernization manifested in the mode of everyday lives. Especially, despite the viewpoint of the latter being embossed as an alternative approach in various areas including the academic world of history since the collapse of socialism, the historical recognition of the phenomena of modern design by the Korean design historians is more like the 'history from the above' that exists at the level of the discourse outside the reality rather than the 'history from the below' that exists within the ordinary life. To grant a sense of balance in such frame of historical understanding, it requires the restructuring the design history of Korea through the cultural perspectives from having the representation of mundane lives realized by the voluntary design activity of the common people as research subjects. One of the methods to acquire an answer to such problem is decoding, in the manner of 'cultural history', the life-long domestic artifact made by Madame Yang, Gap Jo (currently 87 years of age) who is a model of typical Korean mother. Through the historical rumination on the traces of unpretentious lives of the people that has been buried under the grand narrative of the Korean Design History, a new era aimed for the historical prospect of Korean design as cultural history will be possible by excavating the petit yet multi-layered meaning of Korean designs.

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Retrospect on Preventive Medicine Research and its Future (양생의학 연구의 회고와 전망)

  • Kim, Namil
    • The Journal of Korean Medical History
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    • v.29 no.2
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    • pp.71-81
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    • 2016
  • This paper discusses the research of preventive medicine in terms of philosophy and history, publication and people, branch research, applied research, Gi-gong, conduction exercise and so on. Currently, fields of philosophy, history, physical education and Korean Medicine are actively participating in the research on preventive medicine. From the philosophical view, theoretical aspects of preventive medicine are closely examined. From the historical view, the historical context is of focus. From the physical education viewpoint, Gi-gong, gymnastics and physical education philosophy are studied. In the field of Korean medicine where practicality is most important, plans to apply preventive medicine to life are creating new possibilities for research on preventive medicine. In this time where social interest on health is at peak, combined research of basic theory and application will have positive effects on the development of preventive medicine.

A Study of 救急方 from a Historical Perspective (의사학적으로 살펴본 『구급방(救急方)』)

  • Jung, Soon Duk;Kim, Nam Il;Cha, Wung-Seok
    • The Journal of Korean Medical History
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    • v.21 no.2
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    • pp.67-77
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    • 2008
  • 救急醫學 was initiated with the emergence of mankind. 救急方 was written in the federal government and published in the state government taking orders from 世祖 to meet various needs; stabilization of public welfare, reinforcement of the royal authority, a need for a book for common use in the medical field, as well as pure interest in medicine coming from the king himself. 救急 includes not only emergencies but also rapid transitions of diseases encountered in everyday life. 救急方 successes the tradition of 鄕藥救急方 in that it helps anyone to appropriately treat emergencies. 救急簡易方, 救急易解方, and 諺解救急方 of later generations all were directly influenced by 救急方 and carried on the tradition of 救急.

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