• Title/Summary/Keyword: 지가 변화

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A Study on Long-tail Shape of e-journal Usage - focused on a case of K academic library - (전자학술지 이용의 롱테일현상에 관한 연구 - K 대학도서관의 이용 사례를 중심으로 -)

  • Kim, Sun-Ae
    • Journal of Korean Library and Information Science Society
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    • v.50 no.4
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    • pp.203-221
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    • 2019
  • How has the use of academic journals changed since the academic library purchase policy changed from selective journals based on core journals to package purchases by big deal? The purpose of this study is to analyze the effect of supply and size of academic journals in university libraries on the use of journals. For this purpose, this study used the actual usage statistics of e-journals of K Academic Libraries during 2013-2015. The analysis shows that there is a so-called long-tail shape in which demand shifts to niche products that are effective in online platforms. Analysis of the use of academic journals by year for three years showed that the use of electronic journals in K Academic Libraries appeared to be a perfect Pareto shape, which is concentrated in the top 20% of journals. In particular, in 2015, the top 5% of journals accounted for nearly 80% of the total usage. Despite the changes in the supply method and size of academic journals, users' use of journals was still concentrated in core journals.

Identification of High School Students' Understanding on the Reaction Rate Change During Chemical Equilibrium Shift (화학 평형 이동시 반응 속도 변화에 대한 고등학생들의 이해 조사)

  • Park, Jong-Yoon;Yu, Hyun-Hee
    • Journal of the Korean Chemical Society
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    • v.51 no.4
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    • pp.365-374
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    • 2007
  • The purpose of this study is to investigate the students' conceptions about the reaction rate changes during the chemical equilibrium shifts and also whether the questions about basic concepts of the reaction rate are helpful for the students' understanding of reaction rate changes during the chemical equilibrium shifts. The subjects were 100 students in the 12th grade. The questionnaires were composed of A, B, and A' set, which had to be answered sequentially. The A set consisted of questions asking the change of reaction rate when chemical equilibrium was shifted, the B set was to testify the basic concepts of the reaction rate, and the A' set was the same as the A set. The results showed that the students' understanding of the reverse reaction rate change was lower than that of the forward reaction rate change during the equilibrium shift. Also it was found that students' understanding of the reaction rate change caused by adding the reactant was fairly good while their understanding of the reaction rate change caused by temperature increment was very poor. Since the students marked very high scores in the B set questions, their poor understanding for the reaction rate changes during the equilibrium shifts was not seemed to be due to the lacks of the basic knowledge of reaction rate. Instead, it was due to the failure of applying the basic knowledge of reaction rate to the changes of reaction conditions. It was also found that the average scores of A' set were statistically higher than those of A set. It means the B set items were helpful for the students to solve the A' set items. These results evidenced the possibility of set questionnaires could help the students to connect the related concepts in solving the problems.

A Preliminary Study on the Correlation between GRACE Satellite Geoid Data Variation and Volcanic Magma Activity (GRACE 인공위성 지오이드 변화와 화산 마그마 활동 간의 상관관계에 대한 예비 연구)

  • Oh, Chang-Whan;Choi, Sung-Chan;Lee, Deok-Su;Kim, Myung-Deok;Park, Jong-Hyun;Seo, Min-Ho
    • Journal of the Korean earth science society
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    • v.34 no.6
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    • pp.550-560
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    • 2013
  • In this study, the variations of geoid measured by GRACE satellite are investigated in the 20 volcanic areas erupted since 2005, and it is recognized that a detailed geological study is necessary in using geoid data for a research of the magmatic activities under the volcano. Therefore, the relationship between the regional geoid variation obtained by GRACE satellite and the change of magma activity, is studied in Japan's Shinmoedake volcano in the Kirishima volcanic complex whose eruption in 2011 was studied in detail geologically. Throughout this study the increase of geoid from 2002 in the Shinmoedake volcanic area is confirmed to be caused by the increase of gravity under the volcano, which is well matched with geological interpretation of the continuous intrusion of basaltic magma into magma chamber during several years before the 2011 eruption. The result indicates that information of the geoid variation measured by GRACE satellite is useful for monitoring the possibility of volcanic eruption although there is a need to more study to be able to confirm the possibility.

Effects of Socioeconomic Factors and Forest Environments on Demand for Rural Residential Development (농촌 주거지 개발 수요에 대한 사회경제적 요인 및 산림환경의 영향 분석)

  • Lee, Yohan;Ji, Seongtae
    • Environmental and Resource Economics Review
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    • v.25 no.2
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    • pp.199-228
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    • 2016
  • This study investigates the effects of economic factors and forest environments on rural residential area development in seven north central states of the U.S. by focusing on the relative importance of not only economic factors but also forest environments by forest type as core drivers of residential development. An empirical model of locations and magnitudes of population changes since 1950 in the north central region is first constructed, and then a panel model with fixed effects for counties is used to explain population growth by age group over time at the county level. Then a set of three equations is estimated for three major age groups, and a cross-sectional model is estimated for the last time period that regresses county-level environmental amenity variables on fixed effects coefficients for counties. Finally, an equation explaining changes in rural housing density is estimated. The results imply that immigrant age is a key factor influencing the choice of the place of residence and that the effects of environmental amenity factors on population growth and subsequent housing development in a county vary according to the age group.

A Study on Ecological Characteristics and Changes of Vegetation in Hamyangsangrim (함양상림 식생의 생태적 특성 변화 연구)

  • Kim, Dong-Wook;Lee, Seung-Joo;Lee, Soo-Dong;Kim, Ji-Seok;Han, Bong-Ho
    • Korean Journal of Environment and Ecology
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    • v.26 no.4
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    • pp.537-549
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    • 2012
  • The purpose of this study was to provide data for the basic research to found the effective conservation and management plan for the Hamyangsangrim designated as Natural Monument No. 154 and surround areas by analyzing the ecological characteristics such as landuse and actual vegetation, plant community structure, soil chemical property and also to identify the tendency of the ecosystem changes through comparison with past studies. According to analysis the results, the landuse and actual vegetation of survey site was classified as 8 types which were forest, artificial greenspace, plaza and open-space, bare ground and the pavement, water bodies, facilities, agricultural land and etc.. It was also categorized as 38 types according to detailed characteristic. 15 kinds of forest vegetation community types comprising silva were classified among them. The changes of actual vegetation showed little variation that the Quercus serrata-Carpinus tschonoskii forest was the most widely distributed in 2003(forest area ratio is 48.3%) and 2010(forest area ratio is 48.1%), whereas, the Quercus serrata forest declined a more dramatic from 11.6% to 23.2%. The Quercus serrata-Carpinus tschonoskii forest increased sharply(11.6% ${\rightarrow}$ 23.2%) and also the Quercus serrata-Zelkova serrata forest increased steadily(2.2% ${\rightarrow}$ 7.9%). The agricultural land around forest was transformed into artificial green zone. Moreover, water bodies, bare ground and the pavement of areas have increased. In addition, the urbanized area has decreased because the damaged areas inside forest have been restored to the woodlands. According to the result of typical 6 types vegetation communities change, the middle layer trees grew up to the canopy layer trees and was formed the canopy layer structure. The middle layer trees expanded their forces widely. Also new species appeared. And the shrub individuals also more dramatically increased due to the growth of shrubs. The force of Quercus serrata declined as well. However the force of Carpinus tschonoskii and Zelkova serrata expanded and increased in the forest. It must be the result of the ecological vegetation succession and environmentally soundly health recovery by influence of the projects of forest surrounding environment improvement and limitation of access to forest have managed and maintained since 2003. Those sorts of changes seems to be going to develop continuously. In the future Carpinus tschonoskii and Zelkova serrata will not be only codominant in the canopy layer but also Carpinus Tschonoskii, Zelkova serrata, Meliosma myriantha, Sapium japonicum. Styrax obassia and Acer pseudo-sieboldianum will be codominant in the middle layer. As a result, the forest's codominance species are going to be changed such like that.

Improvement of Vulnerability Assessment to Climate Change using LCCGIS (LCCGIS를 활용한 취약성 평가방법의 개선)

  • Kim, Young Soo;Lee, Seung Hoon
    • Journal of Climate Change Research
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    • v.5 no.2
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    • pp.165-178
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    • 2014
  • National and local governmental adaptation plan for climate change will become mandatory in 2015. In order to establish the plan, assessment of vulnerability to climate change needs to be preceded. LCCGIS, a toolkit for vulnerability assessment, has been widely used by many local governments. However, assessment results by LCCGIS are not yet reliable because most of the vulnerability indices applied to LCCGIS have the same value for almost all administrative units in Korea. In this study, proxy variables for hard-collectable indices were introduced, and the results were compared with those without any proxy variables. Vulnerability assessment could be conducted subjectively due to uncertainty. Thus, determination of objective indices, understanding the available data, and changes of indices in local conditions were organized. Results from this study are expected to make vulnerability assessment reliable and contribute to assessing vulnerability to climate change reflecting on local governmental characteristics.

A Study on Scholarly Communication Trends in Korean Library and Information Science Studies through Author Group Analysis (저자집단 분석을 통한 한국 문헌정보학의 학술커뮤니케이션 동향 연구)

  • Jae Yun Lee
    • Journal of the Korean Society for Library and Information Science
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    • v.57 no.2
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    • pp.409-434
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    • 2023
  • This study analyzes the authorship of all articles published in four domestic LIS journals over a 20-year period from 2002 to 2021 to examine the current status of scholarly communication through Korean LIS journals and suggest future prospects. To achieve this purpose, the study analyzed the number of co-authors, the proportion of returning authors, the publishing preference index (PPI), the author group change trend, and the researcher attraction index (RAI). The analysis revealed the level of collaborative research in each journal, the degree of formation of related author groups by journal, the inflection point of author group changes, the characteristics of emerging researchers, and the degree of author sharing between journals. Overall, 2015 was found to be an inflection point where the author community of Korean LIS journals changed. The newer generation of researchers showed a slightly different behavior of publishing papers than the older generation, as they mainly conduct collaborative research. These quantitative results could be triangulated with the qualitative interview data of previous studies to further strengthen the development strategy of Korean LIS journals.

태양 활동의 변화에 따른 변화에 따른 저위도 상부 이온층 변화

  • 김희준;박재흥;민경욱
    • Bulletin of the Korean Space Science Society
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    • 2004.04a
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    • pp.86-86
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    • 2004
  • 다목적 실용위성 1호의 데이터를 이용하여 관측기간인 2000년 6월 28일에서 2001년 8월1일까지의 고도 685km, 22:50LT(Local Time) 이온층을 조사하였다. 데이터는 이온층 측정 센서(Ionospheric Measurement Sensor)로부터 얻은 전자 온도와 전자 밀도를 이용하였으며, 자기 위도로 -60$^{\circ}$-+60$^{\circ}$ 사이의 중ㆍ저위도의 값을 분석하였다. 관측 기간은 지자기 변화를 나타내는 Kp index나 태양 활동을 나타내는 F10.7이 크게 변화한 태양 극대기 기간으로, 이중 일변화의 F10.7을 통해 전자 온도와 전자 밀도의 변화를 조사하였다. (중략)

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남한강 여주~이포 구간에서의 수해지형 고찰

  • 남욱현;김진관;양동윤;김주용;김종욱
    • Proceedings of the KSEEG Conference
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    • 2003.04a
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    • pp.161-164
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    • 2003
  • 하천 주변은 이미 선사시대부터 거주지나 농경지 등으로서 인간활동의 중요한 무대가 되었다. 그러나 하천은 끊임없이 변화하고 있으며, 그 변화는 특히 홍수의 형태로 인간에게 큰피해를 주어왔다. 인간은 이러한 하천의 변화에에 적응하거나 조절하고자 노력하면서 하천이 어떻게 변화하는가에 관심을 갖게 되었다. 자연적 또는 인위적인 변화가 하천과 홍수에 어떻게 영향을 미치는지에 대한 과학적 연구는 이미 수백년 전에 시작되었다. (중략)

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