• Title/Summary/Keyword: 1980s

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Archaeogenetic Research of Excavated Human Bones from the Ancient Tombs (분묘 유적지 출토 인골에 대한 고고유전학 연구)

  • Jee, Sang Hyun;Chung, Yong Jae;Seo, Min Seok
    • Korean Journal of Heritage: History & Science
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    • v.41 no.1
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    • pp.99-108
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    • 2008
  • The paleogenetic analysis has become an increasingly important subject of archaeological, anthropological, biological as well as public interest. Recently, scientific research for human skeletal remains was more activated because of increasing awareness of the valuable archaeological information by the ancient DNA analysis. State of preservation of organic remains vary in different soil and burying environmental condition. Almost all available tissue disappear to analysis ancient DNA of bone in acidic soil caused by climate and geological features in Korea. Many preserved human remains excavated in the 'Heogwakmyo'(limelayered tomb of Chosun Dynasty Period) is able to explain through the relationship between burial conditions and bone survival form the burial method and ceremony. Ancient DNA analysis of excavated human bone form ancient tomb requires to remove contaminants such as microorganism's DNA and soil components that affect authentic results. Particularly, contamination control of contemporary human DNA is major serious problem and should verified by criteria of authenticity. In order to understand migration and culture of ancient population, when possible, ancient DNA studies needs to go abreast both radiocarbon and stable isotope studies because the dietary inferences will suggest ancient subsistence and settlement patterns. Also when the paleogenetic research supported with the arts and humanities research such as physical anthropology and archaeology, more valuable ancient genetic information is providing a unique results about evolutionary and population genetics studies to reconstruct the past.

Varietal Differences in Agronomic Characters under Different Altitudinal Locations with Equal Latitude in Paddy Rice (동일위도상 표고의 차이에 따른 수도품종의 수량형질변이)

  • Park, S.Z.;Lee, E.W.;Lee, B.W.
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.28 no.2
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    • pp.164-172
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    • 1983
  • The present study was conducted to investigate the variations in morphological traits, yield and yield-related components of rice cultivars exposed to different weather conditions by growing at the locations with different altitude but with equal latitude. Three Japonica varieties (Daegoldo, Jinheung, Shin #2) and three Tongil type semi-dwarf varieties(Josaengtongil, Suweon 287, wx 817-65-2-3) were seeded at Suweon on April 21 and transplanted at Suweon ($127^{\circ}$ N37 20', altitude 37m) and Jechun ($128.2^{\circ}$, N37 10', altitude 280-300m) on June 1 with the spacing of 30 $\times$ 15 em. The morphological traits, yield and yield-related components were measured. Culm length, paincle length and 1000-grain weight showed a little increase in Japonica varieties in Jechun as compared to those in Suweon and vice versa in semi-dwarf varieties, showing no significant differences. Number of panicles, per hill and number of spikelets per panicle among yield-related components showed remarkable increase in all varieties in Jechun as compared to those in 'Suweon but such inter-locational differences differed with varieties within varietal group and between varietal groups. On the contrary, grain fertility was higher in Suweon than that in Jechun and in Japonica varieties than that in semi-dwarf varieites , showing greater inter-locational difference in semi-dwarf varieties. Among Japonica varieties Jinheung and Shin #2 showed remarkable increase in yield in Jechun as compared to that in Suweon but in semidwarf varieties it was just the opposite. The importance of each of the yield-related component contributing to yield showed similar tendency 'regardless of locations in Japonica varieties. However, it was evidently different between locations in semidwarf varieties, where number of spikelets per panicle showed greatest direct effect on yield in Suweon but in Jechun so did grain fertility followed by the number of spikelets per panicle.

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Effect of Defoliation and Panicle Removal at Heading Stage on Grain Weight in Rice Plant (수도 출수기의 분벽별 적엽 및 적수처리가 종실중에 미치는 영향)

  • Kim, K.H.;Lee, Y.J.;Kim, S.J.
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.27 no.1
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    • pp.20-27
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    • 1982
  • Two rice varieties were planted and four degrees of defoliated tiller num ber ratio and another four levels of defoliation-panicle removal tiller number ratio were made at heading stage of know the possibility of translocation of photosynthetic products between tillers during grain filling stage of rice plant. The more tillers defoliated in a hill, the less matured grain ratio and the less grain weight per panicle of normal tillers were found. But the matured grain ratio and the grain weight per panicle of tillers defoliated partly in a hill showed higher than those of tillers of completely defoliated plant. No differences of the matured grain ratio and the grain weight per panicle were found between different levels of defoliation-panicle removal tiller number ratio in a hill. But the matured grain ratio and the grain weight per panicle of tillers of completely defoliated plant were significantly lower than those of tillers of partly defoliation-panicle removal treatments. These results indicated that the translocation of photosynthetic products between tillers was possible during grain filling period in rice plant. Source-sink relationship can be applied to interpret the result obtained in this study.

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Trends in truffle mushroom utilization technology: A patent database survey through the first half of 2023 (트러플 활용기술 동향: 2023년 상반기까지의 특허를 중심으로)

  • Hyun-Suk Kim;Moon-Hee Choi;Deuk-Sil Oh;Hyun-Jae Shin
    • Journal of Mushroom
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    • v.21 no.3
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    • pp.88-92
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    • 2023
  • In this review, we examine the latest technological developments in the utilization of truffles, a gourmet ingredient reputed to be one of the "world's three greatest delicacies," considering changing global consumption trends. Global demand for truffles is expected to increase steadily, with an average annual growth rate of 8.9% from 2023 to 2030. As truffles are expensive, the demand for truffles is expected to be concentrated in developed countries such as the United States, European countries, and Japan. In Korea, truffles are utilized in various industries, including food, functional foods, and cosmetics. Korean consumer demand for truffles has consistently remained high since 2019, and truffle products have been performing well in the market. Consequently, there exists substantial potential demand for newly developed truffle-related products and technologies. This review aims to provide objective research information through the systematic analysis of patent applications in Korea and internationally, focusing on technologies involving truffles, and can aid in setting directions for research and development.

A Dynamic exploration of Constructivism Research based on Citespace Software in the Filed of Education (교육학 분야에서 CiteSpace에 기초한 구성주의 연구 동향 탐색)

  • Jiang, Yuxin;Song, Sun-Hee
    • The Journal of the Korea Contents Association
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    • v.22 no.5
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    • pp.576-584
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    • 2022
  • As an important branch of cognitive psychology, "constructivism" is called a "revolution" in contemporary educational psychology, which has a profound influence on the field of pedagogy and psychology. Based on "WOS" database, this study selects "WOS Core database" and "KCI database", uses CiteSpace visualization software as analysis tool, and makes knowledge map analysis on the research literature of "constructivism" in the field of education in recent 35 years. Analysis directions include annual analysis, network connection analysis by country(region) branch, author, institution or University, and keyword analysis. The purpose of the analysis is to grasp the subject areas, research hotspots and future trends of the research on constructivism, and to provide theoretical reference for the research on constructivism. There are three conclusions from the study. 1. Studies on the subject of constructivism have continued from the 1980s to the present. It is now in a period of steady development. 2. Countries concerned with the subject of constructivism mainly include the United States, Canada, Britain, Australia and the Netherlands. The main research institutions and authors are mainly located in these countries. 3. Currently, the keywords constructivism research focus on the clusters of "instructional strategies", and the development of science and technology is affecting individual learning. In the future, instructional strategies will become the focus of structural constructivism research. With the development of instructional technology, it is necessary to conduct research related to the development of new teaching models.

An Estimation on Average Service Life of Public Buildings in South Korea: In Case of RCC (우리나라 공공건물의 내용연수 추정: RCC를 중심으로)

  • Jung-Hoon Kwon;Jin-Hyung Cho;Hyun-Seung Oh;Sae-Jae Lee
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.46 no.1
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    • pp.84-90
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    • 2023
  • ASL estimation of public building is based on how appropriate the maximum age of the asset is derived based on the age record of the asset in the statistical data owned by public institutions. This is because we get a 'constrained' ASL by that number. And it is especially true because other studies have assumed that the building is an Iowa curve R3. Also, in this study, the survival rate is 1% as the threshold value at which the survival curve and the predictable life curve almost coincide. Rather than a theoretical basis, in the national statistical survey, the value of residual assets was recognized from the net value of 10% of the acquisition value when the average service life has elapsed, and 1% when doubling the average service life has elapsed. It is based on the setting mentioned above. The biggest constraint in fitting statistical data to the Iowa curve is that the maximum ASL is selected at R3 150%, and the 'constrained' ASL is calculated by the proportional expression on the assumption that the Iowa curve is followed. In like manner constraints were considered. First, the R3 disposal curve for the RCC(reinforced cement concrete) building was prepared according to the discarding method in the 2000 work, and it was jointly worked on with the National Statistical Office to secure the maximum amount of vintage data, but the lacking of sample size must be acknowledged. Even after that, the National Statistical Office and the Bank of Korea have been working on estimating the Iowa curve for each asset class in the I-O table. Another limitation is that the asset classification uses the broad classification of buildings as a subcategory. Second, if there were such assets with a lifespan of 115 years that were acquired in 1905 and disposed of in 2020, these discarded data would be omitted from this ASL calculation. Third, it is difficult to estimate the correct Iowa curve based on the stub-curve even if there is disposal data because Korea has a relatively shorter construction history, accumulated economic wealth since the 1980's. In other words, "constrained" ASL is an under-estimation of its ASL. Considering the fact that Korea was an economically developing country in the past and during rapid economic development, environmental factors such as asset accumulation and economic ability should be considered. Korea has a short period of accumulation of economic wealth, and the history of 'proper' architectures faithful to building regulations and principles is short and as a result, buildings 'not built properly' and 'proper' architectures are mixed. In this study, ASL of RCC public building was estimated at 70 years.

Assessing the Habitat Potential of Eurasian Otter (Lutra lutra) in Cheonggye Stream Utilizing the Habitat Suitability Index (서식지 적합성 지수를 이용한 청계천 수달의 서식지 평가)

  • In-Yoo Kim;Kwang-Hun Choi;Dong-Wook W. Ko
    • Korean Journal of Environment and Ecology
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    • v.37 no.2
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    • pp.140-150
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    • 2023
  • The Eurasian otter (Lutra lutra) is an apex predator of the riparian ecosystem. It is a keystone and an indicator species; consequently, its presence suggests a sustainable water environment. Otter is a keystone species as a predator at the top of the food web in the aquatic environment and an indicator species representing the health of the aquatic environment. Although Eurasian otters disappeared from the Han River urban water system because of anthropogenic activities like habitat destruction, poaching, and environmental pollution in the 1980s, the species were sighted in the Cheonggye Stream, Jungrang Stream, and Seongnae Stream, which are urban sections of the Han River, in 2016 and 2021. Therefore, it is pertinent to assess the habitat potential in the area for conservation and management measures to ensure its permanent presence. However, existing studies on otter habitats focused on natural rivers and reservoirs, and there is a limit to applying them to habitats artificially confined habitats in narrow spaces such as tributaries in urban areas of the Han River. This study selected the Cheonggye Stream, an artificially restored urban stream, to evaluate its potential as a habitat for Eurasian otters in urban water environments using the habitat suitability index (HSI). The HSI was calculated with selected environment attributes, such as the cover, food, and threat, that best describe the L. lutra habitat. According to the results, the confluence area of Seongbuk Stream and Cheonggye Stream and the confluence area of Cheonggye Stream and Jungnang Stream were suitable otter habitats, requiring appropriate conservation efforts. The HSI model suggests a valuable method to assess the habitat quality of Eurasian otters in urban water environments. The study is crucial as it can help rehabilitate the species' populations by identifying and managing potential Eurasian otter habitats in highly urbanized areas of the Han River basin and its tributaries.

A Study on electrophoresis and Activity of Alcohol Dehydrogenase of Drosophila melanogaster (한국산 노랑초파리 (Drosophila melanogaster) Alcohol dehydrogenase의 전기영동산 및 활성에 대한 연구)

  • Chung, Yong-Jai;Yoon, Youn-Sik
    • The Korean Journal of Zoology
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    • v.23 no.3
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    • pp.125-136
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    • 1980
  • The purpose of the present study is to investigate the electrophoretic patterns of ADH isozymes and activity at various developmental stages of Oregon-R and Kwangju strains of D. melanogaster. The ADH isozymes were seperated by agarose gel plate eletrophoresis and they were stained for ADH activity study. The optical density was measured by using densitometer and the total activity was determined by measuring the enzyme solution's absorbance of 340 nm by spectrophotometer. The results are as follows: 1. At egg stages of Oregon-R and Kwangju strains ADH 2, ADH 3, ADH 4 were observed in te zymograms, but all of ADH 1, ADH 2, ADH 3, ADH 4 and ADH 5 were detected in larval, pupal and imaginal stages. 2. The amount of ADH 1+ADH 2 (anion) was 20-40% and that of ADH 3+ADH 4+ADH 5 (cation) was 60-805. In the developmental stages other, than egg stages, ADH 3 of both strains showed the largest amount among all ADH isozymes, and especially ADH 4 of Kwangju strain showed less amount than that of Oregon-R strain. 3. The total activity of the ADH at the egg stage was found to be the lowest, at larval stage became to be higher and to be lower at pupal stage and then became to be the highest at the imaginal stage. It is noticeable that the activity of the ADH in Kwangju strain was higher than that in Oregon-R strain.

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Predicting Landslide Damaged Area According to Climate Change Scenarios (기후변화 시나리오를 적용한 산사태 피해면적 변화 예측)

  • Song Eu
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.25 no.4
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    • pp.376-386
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    • 2023
  • Due to climate changes, landslide hazards in the Republic of Korea (hereafter South Korea) continuously increase. To establish the effective landslide mitigation strategies, such as erosion control works, landslide hazard estimation in the long-term perspective should be proceeded considering the influence of climate changes. In this study, we examined the change in landslide-damaged areas in South Korea responding to climate change scenarios using the multivariate regression method. Data on landslide-damaged areas and rainfall from 1981-2010 were used as a training dataset. Sev en indices were deriv ed from rainfall data as the model's input data, corresponding to rainfall indices provided from two SSP scenarios for South Korea: SSP1-2.6 and SSP5-8.5. Prior to the multivariate regression analysis, we conducted the VIF test and the dimension analysis of regression model using PCA. Based on the result of PCA, we developed a regression model for landslide damaged area estimation with two principal components, which cov ered about 93% of total v ariance. With climate change scenarios, we simulated landslide-damaged areas in 2030-2100 using the regression model. As a result, the landslide-damaged area will be enlarged more than the double of current annual mean landslide damaged area of 1981-2010; It infers that landslide mitigation strategies should be reinforced considering the future climate condition.

History and Status of the Chum Salmon Enhancement Program in Korea (연어 방류사업의 역사와 현황)

  • Lee, Hae-Sung;Seong, Ki-Baik;Lee, Cheul-Ho
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.12 no.2
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    • pp.73-80
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    • 2007
  • The chum salmon enhancement program in Korea started at Gowon in Hamgyeong nam-do in 1913 and the program has been more active since Yeongdong Inland Fisheries Research Institute was established at Yangyang in 1984. The major activities were the release of chum salmon fingerlings and the catch of adult chum salmon for artificial fertilization. The range of return rate to Korean waters was in $0.72{\sim}1.57%$ during 1990s, but it has declined seriously since 2000. To overcome the low return rate and enhance chum salmon resources in Korean waters, we must understand the mechanisms of mass mortality of chum salmon during their early life in rivers and coastal areas in conjuction with the fluctuation of return rates and climate. In addition, comprehensive and effective habitat protection and restoration policies will be needed.