• Title/Summary/Keyword: History of research

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Early Life History of Coreoperca herzi in Han River, Korea

  • Park, Jae-Min;Jeon, Hyung-Bae;Suk, Ho Young;Cho, Seong-Jang;Han, Kyeong-Ho
    • Development and Reproduction
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    • v.24 no.1
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    • pp.63-70
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    • 2020
  • This study aimed to investigate early life of Coreoperca herzi living in Han River and compare morphological differences between different groups during the development in order to provide basic data for relevant taxonomic research. On average, one female individual spawned 541 to 861 eggs (average 701) at once. After 259 hours, the tail broke out of the egg membrane and hatching began. Immediately after hatching, the larvae were average 7.81±0.10 mm (n=5) in total length. 60 days the juvenile was average 35.9±1.30 mm (n=5) in total length. The white spots spread to the rest of the body, rending the same pattern as that on the body of their broodstock fish.

Evolution of Korean Modern Mathematics in late 19th and early 20th century (근대계몽기.일제강점기 수학교육과 해방이후 한국수학계)

  • Lee Sang-Gu;Yang Jeong-Mo;Ham Yoon-Mee
    • Journal for History of Mathematics
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    • v.19 no.3
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    • pp.71-84
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    • 2006
  • The purpose of the study was to investigate the evolution of Korean modern mathematics in late 19th and early 20th century. This article reveals the efforts of incipient Korean mathematicians who had adopted modern mathematics from western countries and the difficulties and struggles they had to go through at that time. At the end of the article, we discussed our current status in international mathematical society.

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Life History, Ginseng Damage and Chemical Control of the Field Slug, Deroceras varsans A, Adams (들민달팽이의 생활사와 인삼의 피해 및 약제 방제)

  • 김기황;오승환
    • Journal of Ginseng Research
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    • v.14 no.3
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    • pp.421-426
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    • 1990
  • Field and laboratory works were conducted to Investigate the life history, ginseng damage and chemical control effect of the field slug, Deroceras varians A. Adams. D. varians laid eggs from April to June, but a small number of eggs were also found from July to September in the field. Most young slugs grew through the slimmer months to maturity by October. overwintered beneath the moist soil surface, and began feeding and egg-laying in the following April. indicating that D varians have a life cycle in a year. Damage of ginseng plants by D. varina occurred mainly from late April to mid May in the 3rd to 5th year ginseng fields with rice-straw mulching. It seems that this damage is caused by the adults in oviposition periods and related to rice-straw mulching of ginseng fields. In the experiment, ethoprop 5% granule and metaldehyde 6% bait showed relatively high effectiveness in the control of D. varians adults. Bordeaux mixture was more effective when the chemical was sprayed after infestation of the slug than before the infestation and when the 6-12 mixture was used.

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Ocean Policy of Japan: Focusing on the Relations with Pacific Island Nations (일본의 해양 정책 - 태평양 도서국과의 관계를 중심으로)

  • Hyun, Daesong
    • Ocean and Polar Research
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    • v.35 no.4
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    • pp.355-371
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    • 2013
  • The purpose of this study is to explore the history of the relationships between Japan and the Pacific Island Nations in the context of its ocean policy, and to survey the current situation. Particularly, this paper inquires into how Japan's maritime policy, nuclear policy, and official development assistance policy have affected relationships with countries in this region. Firstly, this paper gives a brief overview of the socio-political situations of Pacific Island Nations. Secondly, the history of the 'Southward Advance Theory' adopted as national policy by Japan in the Meiji era is summarized. Thirdly, how Japan successfully re-entered this region despite conflicts surrounding the nuclear issue after the Second World War is explored. Lastly, this paper investigates how official development assistance and PALM (Pacific Island Leaders Meeting) helped to develop relations between Japan and the Pacific Island Nations.

Beta Processes and Survival Analysis (베타과정과 베이지안 생존분석)

  • Kim, Yongdai;Chae, Minwoo
    • The Korean Journal of Applied Statistics
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    • v.27 no.6
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    • pp.891-907
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    • 2014
  • This article is concerned with one of the most important prior distributions for Bayesian analysis of survival and event history data, called Beta processes, proposed in Hjort (1990). We review the current state of the art of beta processes and their application to survival analysis. Relevant methodological and practical areas of research that we touch on relate to constructions, posterior distributions, large-sample properties, Bayesian computations, and mixtures of Beta processes.

Constructional Tradition and Meaning of the Corner High Column Method (귀고주방식의 조영전통과 의미)

  • Hong, Byung-Hwa;Lee, Eun-Soo
    • Journal of architectural history
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    • v.19 no.3
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    • pp.107-124
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    • 2010
  • The coner high column method that is used in the multi-roof building Sungryemoon seems to have been used for the first time during the Choseon Dynasty, and it's characteristics and trend of usage are studied in this paper. In the results, it was confirmed that the coner high column method is economic and structurally safe, and selectively combines the structural factors used in the Chinese seats. It was found that this method was a newly adopted construction method to effectively express the authority of the country with the establishment of a new dynasty. Also the meaning of the method could be guessed since it was continuously used in important structures from the Choseon Dynasty to the Daehan Empire, in spite of the new multi-roof building technologies.

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'.

Seismic Response Analysis of Lightly Reinforced Concrete Shear Walls

  • Rhee, In-Kyu
    • International Journal of Railway
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    • v.3 no.2
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    • pp.73-82
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    • 2010
  • Global and local behaviors of a lightly RC shear walls are investigated in this paper. For the sake of cyclic behaviors, nominal ground accelerations of 0.15 g, 0.40 g and 0.55 g which associated with natural periods of the walls are applied as listed in French CAMUS-2000 shake table test. Modified Kent & Park model, Drucker-Prager model for concrete material and $Giufr\acute{e}$-Menegotto-Pinto model for rebar are used for time history analyses using fiber/solids elements respectively. Alternatively, Eulerian beam analysis are discussed by imposing inelastic hinges at the most possible plastic hinge location using modified Takeda's trilinear model with stiffness reduction. Relative displacements, base shears, bending moments of 5-story shear building with 36-tons of mass under bi-lateral seismic excitation are extracted and compared with EC-8, PS-92 and KBC-09 provisions. Multi-scaled degradation process; material damage, elemental fracture and structural failure in turn is discussed in the view of numerical accuracy, efficiency and limitation depending on three different model-based analyses.

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Probability research of Wooden Die for Drinking Game as ethnic custom mathematics (민속수학과 목제주령구의 확률 연구)

  • Wang, Moon-Ok;Seo, Jung-Choul;Lim, In-Kyoung
    • Journal for History of Mathematics
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    • v.18 no.4
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    • pp.67-84
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    • 2005
  • In this paper, We make mathematics be more interesting and have students participate in class actively through studying the cultural value of mathematics and the ethnic custom mathematics. For studying probability of the usage of Wooden Die for Drinking Game as ethnic custom mathematics which was used in the United Shilla. We study how to apply our methods to our current school curriculum

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Preliminary Design Procedure for Practical Application of Dampers Using Earthquake Response Spectrum (응답스펙트럼을 활용한 감쇠장치 예비 설계절차 제시)

  • Roh, Ji Eun;Lee, Sang Hyun
    • Journal of the Earthquake Engineering Society of Korea
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    • v.23 no.2
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    • pp.109-117
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    • 2019
  • In this study, a design procedure for the practical application of the dampers to building structures under earthquake loads was presented by using earthquake response spectrum. Nonlinear time history results using a 10 story building structure installed with damper verified the effectiveness of the proposed procedure by showing that the structural response could be reduced to the target performance level for seismic loads. Since the proposed design procedures are based on response spectrum seismic analysis result of the original structure, the capacity, location and the number of damper and the consequent response reduction effects can be preliminarily determined without performing the nonlinear time history analysis.