• Title/Summary/Keyword: time-geography

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Cosmogenic 10Be Depth Profile Dating of Strath Terrace Abandonment using Monte Carlo Simulation (몬테카를로 시뮬레이션을 이용한 하안단구 10Be 수직단면 연대측정)

  • Kim, Dong-Eun;Seong, Yeong Bae;Kim, Jong-Geun
    • Journal of The Geomorphological Association of Korea
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    • v.26 no.4
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    • pp.21-31
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    • 2019
  • Timing of terrace formation is a key information for understanding the evolution of fluvial systems. In particular, dating strath terrace (i.e. timing of terrace abandonment) is more difficult than depositional terrace that is conventionally constrained by radiocarbon, OSL and other dating methods targeting samples within terrace deposit. Surface exposure dating utilizing cosmogenic 10Be provides more reliability because it can be applied directly to the surface of a fluvial terrace. Thus, this method has been increasingly used for alluvial deposits. As well as other geomorphic surfaces over the last decades. Some inherent conditions, however, such as post-depositional 10Be concentration (i.e. inheritance), surface erosion rate, and density change challenge the application of cosmogenic 10Be to depositional terrace surface against simple bedrock surface. Here we present the first application of 10Be depth profile dating to a thin-gravel covered strath terrace in Korea. Monte Carlo simulation (MCS) helped us in better constraining the timing of abandonment of the strath terrace, since which its surface stochastically denuded with time, causing unexpected change of 10Be production with depth. The age of the strath terrace estimated by MCS was 109 ka, ~4% older than the one (104 ka) calculated by simple depth profile dating, which yielded the best-fit surface erosion rate of 2.1 mm/ka. Our study demonstrates that the application of 10Be depth profile dating of strath terrace using MCS is more robust and reliable because it considers post-depositional change of initial conditions such as erosion rate.

Reshaping the FDI Network in the Global Economic Environment (글로벌 경제 환경과 해외직접투자 네트워크의 공간적 재편)

  • Kisoon Hyun
    • Journal of the Economic Geographical Society of Korea
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    • v.26 no.3
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    • pp.256-273
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    • 2023
  • This study analyzed the structural changes in the global foreign direct investment (FDI) network using stock data from the International Monetary Fund's Coordinated Direct Investment Survey (CDIS) for 2009~2021. The results showed that the COVID-19 pandemic had a negative impact on the FDI links between countries and the activities of reciprocal relationships. The United States, the Netherlands, and the United Kingdom consistently play central roles in the global FDI network. The degree centrality of China has changed significantly over time in confronting the volatile situation of the world economy. Cross-tabulation analysis revealed a significant association between FDI clusters and geographic regions. Within each cluster, the linkage structure of FDI partners of closely connected individual countries has exhibited differential characteristics as the global economic environment changes.

A Study on the Specialized Classrooms of Governmental Secondary Schools in the Japanese Colonial Era -Focused on Architectural Drawings for Collected by National Archives of Korea (일제 강점기 관립 중등학교 특별교실에 관한 연구 -국가기록원 소장 학교건축 도면을 중심으로)

  • Lee, Jeong-Woo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.4
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    • pp.2476-2483
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    • 2014
  • This study aims to review the characteristics of specialized classrooms for governmental secondary schools in the Japanese Colonial Era by analyzing architectural drawings collected by National Archives of Korea. The results of this study are summarized as follows 1) Under the influence of Japanese science promotion of that time, specialized classrooms for science were considered as one of essential facilities. Typically exclusive specialized classrooms were assigned to two major science subjects : physics-chemistry and biology. 2) To science specialized classrooms, ancillary rooms for preparation, experiment equipment and specimen were attached and science lecture room with stepped floor was planned additionally only for the lecture on theories and the demonstration of experiment. 3) Specialized classrooms for science were zoned independently of other facilities because of the special equipments and safety. 4) Art rooms were common to both boys' and girls' schools but concerning music rooms, girls' schools had special concerns, whereas boys' schools did not. 5) Specialized classrooms for homemaking subject of girls' school were as much important as those for science subjects of boys' school. 6) Some early-established Korean boys' schools had handicraft rooms which were the symbol of vocational education-oriented, unequal policy on Koreans. Though not general cases, specialized classrooms for geography-history were planned for Japanese boys' school. Restricted to governmental secondary schools but considering the uncommon state of specialized classrooms of that time, these characteristics show conditions of early time when special classrooms were introduced into Korea.

Dietary Tea Catechin Inclusion Changes Plasma Biochemical Parameters, Hormone Concentrations and Glutathione Redox Status in Goats

  • Zhong, Rongzhen;Xiao, Wenjun;Ren, Guopu;Zhou, Daowei;Tan, Chuanyan;Tan, Zhiliang;Han, Xuefeng;Tang, Shaoxun;Zhou, Chuanshe;Wang, Min
    • Asian-Australasian Journal of Animal Sciences
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    • v.24 no.12
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    • pp.1681-1689
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    • 2011
  • The beneficial effects of tea catechins (TCs) are related not only to their antioxidant potential but also to the improvement of animal meat quality. In this study, we assessed the effects of dietary TC supplementation on plasma biochemical parameters, hormone responses, and glutathione redox status in goats. Forty Liuyang goats were randomly divided into four equal groups (10 animals/group) that were assigned to four experimental diets with TC supplementation at 4 levels (0, 2,000, 3,000 or 4,000 mg TC/kg DM feed). After a 60-day feeding trial, all goats were slaughtered and sampled. Dietary TC treatment had no significant effect on blood biochemical parameters, however, low-density lipoprotein cholesterol (p<0.001), triglyceride (p<0.01), plasma urea nitrogen (p<0.01), and glucose (p<0.001) decreased and total protein (p<0.01) and albumin (p<0.05) increased with the feeding time extension, and day 20 was the turning point for most of changes. Interactions were found in glutathione (p<0.001) and the ratio of reduced and oxidized glutathione (p<0.05) in whole blood between treatment and feeding time. Oxidized glutathione in blood was reduced (p<0.05) by 2,000 mg TC/kg feed supplementation, and a similar result was observed in longissimus dorsi muscle. Though plasma glutathione peroxidase (p<0.01) and glutathione reductase (p<0.05) activities were affected by treatment and feeding time interactions, and glutathione S-transferases activity increased with feeding day extension, no changed values appeared in longissimus dorsi muscle. In conclusion, dietary TC supplementation affected the concentrations of some blood metabolites and accelerated GSH depletion in the blood of goats. In terms of less high-density lipoprotein cholesterol, the highest insulin and IGF-I concentrations, the highest ratio of reduced and oxidized glutathione in plasma, the dosage of 2,000 mg TC/kg feed might be desirable for growing goats to prevent glutathione depletion and keep normal physiological metabolism.

A Study on the Improvement of Huff's Method in Korea : I. Review of Applicability of Huff's method in Korea (Huff 강우시간분포방법의 개선방안 연구 : I. Huff방법의 국내유역 적용성 검토)

  • Jang Su-Hyung;Yoon Jae-Young;Yoon Yong-Nam
    • Journal of Korea Water Resources Association
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    • v.39 no.9 s.170
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    • pp.767-777
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    • 2006
  • The goal of this study is to improve Huff's method which is the most popular method for rainfall time distribution in Korea. As the first step, we reevaluated the context of Huff's original research motivations, geography and rainfall pattern of study area, and compared that to Korean situations. In original Huff's results, no change in temporal distribution characteristics were found for different rainfall durations. This was found to be different from Korean situations. Furthermore, results from the MOCT(Ministry of Construction and Transportation) version of Huff's method is on a gage basis not on a watershed basis, thus making it difficult to select cumulative rainfall curves representative of a watershed. In addition, all rainfall data regardless of their magnitude were used in the MOCT version of Huff' method which is different from original Huff's which screened out data by using a threshold value of 25.4mm. For both point and areal mean rainfall, time distribution characteristics of rainfall for various durations were found to be different. This was statistically proven by K-S test at 5% significance level as some cumulative rainfall curves developed from the rainfall data of certain durations were found to be not significant with cumulative rainfall curves developed from the rainfall data of all durations. Therefore, in order to apply Huff's method to Korean situations, it is recommended that dimensionless cumulative curve must be developed for various rainfall duration intervals using rainfall data greater than a certain threshold value.

The Locations of the Weekly Periodic Markets in Jinju and the Characteristics of Their Merchants (진주시 요일장의 입지와 요일장 상인의 특성에 대한 연구)

  • Lee, Jeon
    • Journal of the Korean association of regional geographers
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    • v.16 no.5
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    • pp.517-536
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    • 2010
  • While periodic marketing systems have lasted for more than hundreds of years in Korea, the weekly (periodic) markets have emerged since the latter half of the 1990s in the densely populated urban areas. In Jinju, weekly markets are opened on eight densely populated area: Ehyeon Wellga Apt.(Monday market), Gumsan Apt.(Tuesday market), Juyak Hanbo Apt.(Wednesday market), Chojeon Apt.(Thursday market), Manggyeong Hanbo Apt.(Thursday market), Pyeonggeo Dulmalhanbo Apt.(Friday market), Gajoa Jugonggreenville Apt.(Saturday market), and Gaho Apt.(Saturday). The merchants of Jinju's weekly markets can be classified into three groups as follows: the migrating specialized(full-time) merchants, who sell fruits, fish, and other daily necessities: the farmer part-time women merchants in the sixties or in the seventies, who sell the agricultural products that they themselves have grown around the rural areas; and the vendor merchants, who sell mostly dduk-bok-ki, eo-mug(odeng), and other fast food. The origin and persistence of periodic markets are explained in terms of the concepts of central place theory, the economic/comparative advantage of periodic markets, and the traditional organization of time and inertia.

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Satellite-Measured Vegetation Phenology and Atmospheric Aerosol Time Series in the Korean Peninsula (위성기반의 한반도 식물계절학적 패턴과 대기 에어로졸의 시계열 특성 분석)

  • Park, Sunyurp
    • Journal of the Korean Geographical Society
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    • v.48 no.4
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    • pp.497-508
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    • 2013
  • The objective of this study is to determine the spatiotemporal influences of climatic factors and atmospheric aerosol on phenological cycles of the Korea Peninsular on a regional scale. High temporal-resolution satellite data can overcome limitations of ground-based phenological studies with reasonable spatial resolution. Study results showed that phenological characteristics were similar among evergreen forest, deciduous forest, and grassland, while the inter-annual vegetation index amplitude of mixed forest was differentiated from the other forest types. Forest types with high VI amplitude reached their maximum VI values earlier, but this relationship was not observed within the same forest type. The phase of VI, or the peak time of greenness, was significantly influenced by air temperature. Aerosol optical thickness (AOT) time-series showed strong seasonal and inter-annual variations. Generally, aerosol concentrations were peaked during late spring and early summer. However, inter-annual AOT variations did not have significant relationships with those of VIs. Weak relationships between AOT amplitude and EVI amplitude only indicates that there would be potential impacts of aerosols on vegetation growth in the long run.

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Analysis of Changes in Land Use of Hills Using Time Series Data (시계열 자료를 활용한 야산의 토지이용 변화 분석)

  • Park, Jong-Chul;Kim, Man-Kyu
    • Journal of the Korean Association of Geographic Information Studies
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    • v.13 no.3
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    • pp.102-118
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    • 2010
  • Since hills are transitional area between plains and mountains, they are always under pressure to be developed. In the past, hills were recognized as areas that can be developed easily, but in the present they should be considered and preserved as forest resources. So far, little research has been done regarding cultivation status and transitional procedure. This study attempts to quantify changes in land use using time series data. To do so, this study has created a land use map for 1915, 1972, 2002 and 2006, and conducted a spatial analysis based on GIS. The research areas(the total size of the hills are 3,034 ha) are located in Chungcheongnam-do of South Korea. The size of the forest area of the hills in the research zone has decreased by 50% during the period of 1915 to 2006. The size of the reduced forest area after 2002 is similar to size of the reduced area that had taken place for the last 30 years before 2002. The reduction in forest area in the research area has led to increases in paddy field, upland field, artificial structures, and bare land. From 1915 to the late 1980s, hill development had been related to the primary industry and after the late 1980s, it has associated with the development of the secondary industry including industrial complex.

Spatio-temporal Characteristics of the Daily Activities of economic-active married women (취업주부의 일상생활활동의 시 ${\cdot}$ 공간적 특성)

  • Park, Soon-Ho;Kim, Enn-Sook
    • Korea journal of population studies
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    • v.21 no.2
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    • pp.113-143
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    • 1998
  • Married women who follow occupations have remarkably increased. Economic-activies married women[EAMW] have experienced a great degree of role confilcts as the results of that they should play the role of wage workers and do duty as household affairs as well as raise children. To understand problems of EAMW and to make alterniative plans for EAMW, the daily life actives of EAMW should be examined. This study attempts to understand the daily life activites of EAMW. To obtain the goal this research generalizes the daily life actives of EAMW. classifies the patterns the activites, and analyzes the activites in the micro-level. The acivites of EAMW mainly consist of formal business and household affairs. The spatial bounds of activities are influenced by weekdays and holidays. During the weekday their activities are mainly found around residences and/or work places; while, during the weekend, they are discovered around residences and/or around residences or relatives who take care of their children. EAMW move longer distance rather than a full-time housewife; however, the activites of EAMW are residential orientation like those of full-time housewives. The role conflicts of EAMW are mainly from social cultural structure, the distance between workplace and residence, and the location of public service institutes.

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Development of a 2 Dimensional Numerical Landscape Evolution Model on a Geological Time Scale (2차원 지질시간 규모 수치지형발달모형의 개발)

  • Byun, Jong-Min;Kim, Jong-Wook
    • Journal of the Korean Geographical Society
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    • v.46 no.6
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    • pp.673-692
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    • 2011
  • Advances in computer technology have enabled us to develop and use numerical landscape evolution models (NLEMs) for exploring the dynamics of geomorphic system from a variety of viewpoints which previously could have not been taken. However, as of yet there have been no trials using or developing NLEMs in Korea. The purpose of this research is to develop a 2 dimensional NLEM on a geological time scale and evaluate its usefulness. The newly developed NLEM (ND-NLEM) treats bedrock weathering as one of the major geomorphic processes and attempts to simulate the thickness of soil. As such it is possible to model the weathering-limited as well as the transport-limited environment on hillslopes. Moreover the ND-NLEM includes not only slow and continuous mass transport like soil creep, but also rapid and discrete mass transport like landslides. Bedrock incision is simulated in the ND-NLEM where fluvial transport capacity is large enough to move all channel bed loads, such that ND-NLEM can model the detachment-limited environment. Furthermore the ND-NLEM adopts the D-infinity algorithm when routing flows in the model domain, so it reduces distortion due to the use of the steepest descent slope flow direction algorithm. In the experiments to evaluate the usefulness of the ND-NLEM, characteristics of the channel network observed from the model results were similar to those of the case study area for comparison, and the hypsometry curve log during the experiment showed rational evidence of landscape evolution. Therefore, the ND-NLEM is shown to be useful for simulating landscape evolution on a geological time scale.