• Journal of the Korean association of regional geographers
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• v.12 no.5
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• pp.583-594
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• 2006

Relics are life traces of ancestors, and they are good data for giving an idea about space locations of that period. This study classifies relics according to their type, and for each classified group metrical analysis is carried out using GIS and triangle diagram. The criteria used for analysis of relics' locations are elevation, road accessibility and water accessibility. The analysis results show that every relic has its own distribution characteristics according to the time and the type. This means high possibility of approaching a geographical focus on relics distribution and location. While historical period was taking over prehistorical, relics locations moved from the points of great usage water supply possibility to the points of great traffic accessibility. Also, relics of the ruling class for each time period generally have good locations.

• Atmosphere
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• v.23 no.1
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• pp.73-83
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• 2013

In recent several years, East Asia, Europe and North America have suffered successive cold winters and a number of historical records on the extreme weathers are replaced with new record-breaking cold events. As a possible explanation, several studies suggested that cryospheric conditions of Northern Hemisphere (NH), i.e. Arctic sea-ice and snow cover over northern part of major continents, are changing significantly and now play an active role for modulating midlatitude atmospheric circulation patterns that could bring cold winters for some regions in midlatitude. In this study, a dynamical seasonal prediction system for NH winter is newly developed using the snow depth initialization technique and statistically predicted sea-ice boundary condition. Since the snow depth shows largest variability in October, entire period of October has been utilized as a training period for the land surface initialization and model land surface during the period is continuously forced by the observed daily atmospheric conditions and snow depths. A simple persistent anomaly decaying toward an averaged sea-ice condition has been used for the statistical prediction of sea-ice boundary conditions. The constructed dynamical prediction system has been tested for winter 2012/13 starting at November 1 using 16 different initial conditions and the results are discussed. Implications and a future direction for further development are also described.

• Journal of Astronomy and Space Sciences
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• v.27 no.4
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• pp.263-278
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• 2010

Many filtered CCD measures form the basis of six new light curves of the eclipsing system SW Lyn. From these measures and additional observations for eclipse timing, 47 new times of minimum light over the time-interval of about 13 years have been calculated. The complex period variability can be sorted into a linear period improvement with 5.8-year and 33.9-year periodic terms. The shorter cyclic term of these is ascribed to a cool companion of the eclipsing pair but the longer one has no testable interpretation at present. The new light curves are synthesized by the 2003 version of the Wilson-Devinney differential corrections computer code. The results incorporate a source of "third light" which comes from the cool companion star that had been identified by the cycling of the period of the eclipsing pair and also had previously been identified spectroscopically. There is a measure of satisfaction with current understanding of the SW Lyn eclipsing system because of consistent syntheses of all historical light curves. This agreeable convergence, however, comes partly at the expense of an unanticipated temperature of the hot star and of a photospheric spot that has no obvious basis in the detached character modeled for the binary. We offer predictions of changes in the stellar parameters if the modeled detached-configuration should be wrong. The SW Lyn stellar system is still difficult to understand.

• Journal of Korean Library and Information Science Society
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• v.47 no.4
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• pp.411-441
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• 2016

This research examined the composition background of Miscellaneous Explanations of Seongho(湖僿說), the representative work of Yi Ik(李瀷, pen name is Seongho 星湖, 1681-1763), then selected the 443 cited references in the book, and analyzed the features of them such as the scales and characteristics of reference, the proportion of Chinese books, the ratio of latest editions and the relative importance by subjects. After examining the ratio of Goryeo-Joseon and Chinese books among 443 references in Miscellaneous Explanations of Seongho, it was revealed that there were 23.3% of Goryeo-Joseon books and 76.7% of Chinese books cited. The investigation on the editorial period of the referred Chinese books showed that 70% and more were books of the Song and pre-Song period, whereas 22.7% were books of the Ming-Qing period. The analyzation of the proportions of the reference by subject showed that the subject fields with highest percentage appeared in the order of historical books, poetry and prose collections, Confucian classics, and novels and essays. And besides these subjects, he had been interested in various subjects: Miscellaneous Schools, Confucian School, geography, regulation of systems, painting and music, dictionary, biography, encyclopedia, and so on.

• Korea journal of population studies
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• v.18 no.2
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• pp.98-114
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• 1995

Since 1962 the Korean society has undergone a rapid transformation under government policies to achieve maximum economic growth. Urbanization via massive rural to urban migration has been observed to be connected with a rapid economic development. Based on the data from the government publications such as Population and Housing Census Reports and Korean Urban Yearbooks, this study measures inequalities in terms of the distribution of urban population. In a historical context, the pace of urbanization during the period 1966-1970 was characterized as the most rapid and the urban-rural growth difference(URGD), which is a valuable measure of the pace of urbanization, was the highest. In terms of regional pattern, Seoul dominated the urbanization picture of Korea during the period 1966-1970. Its annual growth rate was the fastest among those shown during the period 1960 to 1990 and also highest. However, Seoul's primacy was pulled down since 1970. The Gini coefficient, which is the most common general measure of inequalities in distribution, was the highest in 1980. Since 1980 it has continued to fall. As a result, it was lower in 1990 than in 1970. Despite lowering Gini coefficient, inequalities are still large. A concentration index also showed the same trends as those of Gini coefficent.

• Publications of The Korean Astronomical Society
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• v.33 no.2
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• pp.9-19
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• 2018

We investigate the life of Lee Cheon (1376-1451) who was closely connected with astronomy during the reign of King Sejong of the Joseon dynasty. Lee Cheon is widely regarded as one of the outstanding scientists of King Sejong's period. However, his contributions to the development of the astronomy during the period have not been enlightened. Based on the historical records on the life and achievements of Lee Cheon, mainly referring to the Joseonwangjosillok (Annals of the Joseon Dynasty), we address three important points. First, Lee Cheon was a distinguished administrator who filled various government posts. Second, he was a supervising engineer in public works and metal smelting during his position in military. Third, he was a scientific technician and manufactured precision equipment such as the metal movable type sets. By virtue of these aspects, Lee Cheon was taken into confidence by King Sejong on the Ganui-dae project (i.e., manufacture various astronomical instruments and construct their platform in order to make a calendar suitable for Joseon). During the period of this project, Lee Cheon not only supervised the construction of the Ganui (simplified armillary sphere) and Ganui-dae (platform for astronomical instruments) but also participated in the production of the astronomical instruments such as Gyupyo (Gnomon) and Honcheonui (Armillary Sphere). In conclusion, we regard Lee Cheon as one of the astronomers who led a great advance in astronomy during King Sejong's era.

• Journal of the Earthquake Engineering Society of Korea
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• v.14 no.4
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• pp.17-22
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• 2010

In this study, a tsunami hazard curve was determined for a probabilistic safety assessment (PSA) of a tsunami event at a Nuclear Power Plant site. A Tsunami catalogue was developed by using the historical tsunami record prior to 1900 and the instrumental tsunami record after 1900. For the evaluation of the return period of the tsunami run-up height, power-law, upper-truncated power law and exponential function were considered for the assessment of regression curves and each result was compared. Although there were in total only 9 tsunami records on the east coast of Korea during the time period of the tsunami catalogue, there is no research like this about tsunami hazard curve evaluation, so this research lays a foundation for probabilistic tsunami hazard assessment (PTHA)

• Journal of Agricultural Extension & Community Development
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• v.4 no.1
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• pp.231-243
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• 1997

Objective of the study was to investigate characteristics and meanings of the agricultural extension work during the period of Japanese $rule(1906{\sim}1945)$ through historical review on the work. The agricultural extension work during the period of Japanese rule was categorized into six patterns such as agricultural extension work by (1) government agricultural administration system, (2) agricultural experiment/research institute, (3) public school, (4) through the movement of rural development(Nong-chon-Jinheung Undong), (5) pro-government private organization, and (6) pure private organization. In conclusion, the characteristics of the extension work were defined; 1) a tool and/or method for colonial rule, 2) non-democratic and top-down extension work by administration, 3) authoritative and coercive work initiated by governmental system, 4) nation wide work of cooperation with public and private organization, 5) extension work focused on production increasing food and industrial materials, and 6) extension work initiated by government system without participation of pure private organization. The meanings of the extension work were reviewed in two ways. Firstly, in macro point of view, the work has negative meaning that was utilized as a tool and/or method for Japanese colonial rule, since the extension work was implemented under the direction of agricultural policy and was also directly related to the policy of Japanese colonial government. Secondly, in micro point of view, the work has significant meaning either negative or positive such as 1) beginning of modernized extension work based on experiment and research, 2) introduction of forcible agricultural extension work, 3) inducement of distrust tendency to agricultural policy and agricultural extension work, 4) establishment of basis in hardware of agricultural extension work, 5) production of experience in software of agricultural extension work, and 6) improvement of recognition toward scientific farming and improvement of level in agricultural techniques.

• Atmosphere
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• v.20 no.3
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• pp.261-271
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• 2010

Carbon isotopic compositions of the YC-2 stalagmite in Yongcheon Cave were analyzed to delineate paleoclimatic variations near Korean peninsula for the past historical period. The YC-2 stalagmite is about 68 mm long and annual growth laminae are distinctively identified. Because the number of growth laminae is at least 242, the stalagmite can be estimated to be at least 241 years old. At about 15 mm from the bottom, one thick brown growth lamina is observed, and this lamina was likely to have been formed when the stalagmite ceased to grow, making the hiatus. High resolution, carbon isotope data indicate past fluctuations of East Asia monsoonal intensity (intimately related to the amount of precipitation). Based on the carbon isotope trend, the stalagmite can be divided into three stages (Stages I, II and III). The highest carbon isotopic compositions of Stage I (${\delta}^{13}C$=-3.3~0.4‰, PDB) indicate that the stalagmite grew during the Little Ice Age when cold and dry climate prevailed with less vegetation. Stage II is characterized by a transitional period from cold and dry to warm and wet climate with a increasing trend of carbon isotopic compositions (${\delta}^{13}C$=-9.6~-0.6‰) and this period indicates the weakening of the Little Ice Age climate. This decreasing trend also suggests that Little Ice Age was terminated near middle 1870's around Korean peninsula. Relatively low carbon isotopic compositions during Stage III (${\delta}^{13}C$=-11.0~-8.0‰) indicates that the climate was changed to warm and wet conditions which are similar to the present.

• Journal of Preventive Medicine and Public Health
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• v.35 no.1
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• pp.65-71
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• 2002

Objective : To estimate the status of HIV infection and AIDS incidence using a back-calculation model in Korea. Methods : Back-calculation is a method for estimating the past infection rate using AIDS incidence data. The method has been useful for obtaining short-term projections of AIDS incidence and estimating previous HIV prevalence. If the density of the incubation periods is known, together with the AIDS incidence, we can estimate historical HIV infections and forecast AIDS incidence in any time period up to time t. In this paper, we estimated the number of HIV infections and AIDS incidence according to the distribution of various incubation periods Results : The cumulative numbers of HIV infection from 1991 to 1996 were $708{\sim}1,426$ in Weibull distribution and $918{\sim}1,980$ in Gamma distribution. The projected AIDS incidence in 1997 was $16{\sim}25$ in Weibull distribution and $13{\sim}26$ in Gamma distribution. Conclusions : The estimated cumulative HIV infections from 1991 to 1996 were $1.4{\sim}4.0$ times more than notified cumulative HIV infections. Additionally, the projected AIDS incidence in 1997 was less than the notified AIDS cases. The reason for this underestimation derives from the very low level of HIV prevalence in Korea, further research is required for the distribution of the incubation period of HIV infection in Korea, particularly for the effects of combination treatments.