• The Bulletin of The Korean Astronomical Society
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• v.43 no.2
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• pp.58.3-59
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• 2018

We investigate velocity oscillations in a solar quiet region by using the spectral data of the $H{\alpha}$ and Ca II $8542{\AA}$ lines. The data were acquired by the Fast Imaging Solar Spectrograph installed at the 1.6 m Goode Solar Telescope of Big Bear Solar Observatory. According to Chae & Litvinenko (2018)'s theoretical work, there is a correlation between dominant period of the oscillations and the temperature of the temperature minimum region in a non-isothermal atmosphere. In our study, we measure the temporal variations of the intensity and the line of sight Doppler velocity, and find out the relations between the intensity and dominant period of the oscillations. In addition, we investigate oscillations in a few distinct regions and discuss regional characteristics of the oscillations.

• East Asian Economic Review
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• v.28 no.1
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• pp.37-67
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• 2024

This paper analyses carbon emissions and value-added embodied in trade between two large developed countries, South Korea and the United States, during 2000-2014. Using multi-regional input-output (MRIO) tables, our analysis reveals that carbon emissions and value-added embodied in exports grew by 19% and 101% for South Korea but shrank by 43% and 7% for the United States. As a result, South Korea experienced a 40% increase in net carbon exports and 243% increase in net value-added exports. At the industry level, the primary drivers of changes in carbon exports were electricity and basic materials. The majority of industries in witnessed improvements in carbon intensities suggesting improved environmental efficiency. While both countries achieved a decoupling of carbon emissions from value-added exports, substantial year-to-year and sectoral variations were observed. Finally, structural decomposition analysis indicates that domestic supply-side factors played a role in decreasing emissions whereas foreign demand-side factors contributed to emissions increases. In line with the main findings, various implications for policy and future research are discussed.

• Journal of Positioning, Navigation, and Timing
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• v.13 no.1
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• pp.35-44
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• 2024

This investigation primarily focuses on the generational characteristics of satellites utilized in the existing Global Navigation Satellite System (GNSS) and Regional Navigation Satellite System (RNSS), with a central emphasis on comparing the operational status of the latest generation satellites. Variations among satellite generations in physical attributes, energy consumption, and timekeeping are observed, enabling an exploration of the developmental trends over successive generations. Through a comparative analysis of the latest generation satellites, particularly in terms of performance, this study aims to furnish essential insights into the satellites employed within each system. Consequently, it will contribute to a foundational understanding of the past, present, and future GNSS satellites.

• Journal of the Korean earth science society
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• v.43 no.2
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• pp.283-302
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• 2022

Despite the nationwide COVID-19 lockdown in China since January 23, 2020, haze days with high PM₁₀ levels of 88-98 ㎍ m^-3 occurred on February 1 and 2, 2020. During these haze days, the East Asian region was affected by a warm and stagnant air mass with positive air temperature anomalies and negative zonal wind anomalies at 850 hPa. The Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) was used to analyze the variation of regional PM₁₀ aerosol transport in Korea due to decreased anthropogenic emissions in East Asia. The base experiment (BASE), which applies the basic anthropogenic emissions in the WRF-Chem model, and the control experiment (CTL) applied by reducing the anthropogenic emission to 50%, were used to assess uncertainty with ground-based PM₁₀ measurements in Korea. The index of agreement (IOA) for the CTL simulation was 0.71, which was higher than that of BASE (0.67). A statistical analysis of the results suggests that anthropogenic emissions were reduced during the COVID-19 lockdown period in China. Furthermore, BASE and CTL applied to zero-out anthropogenic emissions outside Korea (BASE_ZEOK and CTL_ZEOK) were used to analyze the variations of regional PM₁₀ aerosol transport in Korea. Regional PM₁₀ transport in CTL was reduced by only 10-20% compared to BASE. Synthetic weather variables may be another reason for the non-linear response to changes in the contribution of regional transport to PM₁₀ in Korea with the reduction of anthropogenic emissions in East Asia. Although the regional transport contribution of other inorganic aerosols was high in CTL (80-90%), sulfate-nitrate-ammonium (SNA) aerosols showed lower contributions of 0-20%, 30-60%, and 30-60%, respectively. The SNA secondary aerosols, particularly nitrates, presumably declined as the Chinese lockdown induced traffic.

• Journal of Digital Convergence
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• v.13 no.11
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• pp.241-254
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• 2015

This study examined changes in health behavior and prevalence of hypertension and diabetes during five years and analyzed determinants affecting on geographic variations of them. Data from Korean Community Health Survey in the period of 2008 and 2013 with 246 small districts were analyzed. Data were analyzed using convergence tools such as geographic information system tool and decision tree. During the five years period, areas of the increases in smoking and drinking were southwest regions showed increased smoking and areas of increases in physical activity are western regions. Areas of the increases in the prevalence of hypertension were west and south regions and in the prevalence of diabetes were east and north regions. Determinants affecting on regional variations in the prevalence of hypertension and diabetes were drinking, physical activity, obesity, arthritis, depressive symptom and stress. Mental health program should be developed for non-communicable disease. Thus, to decrease the prevalence of hypertension and diabetes, our study emphasized the necessity to develop customized mental health policies according to the region-specific characteristics.

• Journal of Digital Convergence
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• v.13 no.10
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• pp.425-436
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• 2015

This study is to investigate how the expenditures for hypertension is affected by socioeconomic, health care resources, and health behavior factors with a special emphasis on geographic variations and to provide the data about regional management for hypertension. To analyze, we combined a unique data set including key indicators from Medical Service Usage Statistics 2012 by Region by National Health Insurance Corporation, Annual Community Health Survey 2012 by Korea Centers for Disease Control and Prevention and other government organizations at the 247 small administrative districts. We found that the average expenditures of hypertension in 249 small districts is 62,000 won and coefficient of variation is 30.0. Major factors of differences in hypertension expenditure is population density, marital status, household income, number of hospital per 100 thousand, medical expenses outside the jurisdiction, drinking rate, moderate and over-intensity physical activity, and hypertension diagnosis rate. The results of decision tree was that there were significant differences between regions in hypertension diagnosis rate, household income, marital status, number of hospital per 100 thousand, obesity rate, drinking rate. This study concluded that determinants of geographic variations in hypertension spending are not only health resources and socioepidemic characteristics but health behaviors.

• Journal of Preventive Medicine and Public Health
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• v.27 no.3 s.47
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• pp.609-626
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• 1994

This study was conducted to investigate whether variations in hospital services utilization across small geographic areas in Korea existed, and if so, what factors are responsible for the variation. The claims data of the fiscal year 1992 obtained from the regional health insurance societies were used for the study. Main findings of the research can be summarized as follows: 1 Extremal Quotients (EQ) of hospital expenditure per capita and hospital days per capita were 2.69 and 2.73, and Coefficient of Variation (CV) were 0.14, both, respectively. The EQ and the CV of admission rate were also 2.71, 0.15. The EQ and the CV of expenditure per admission were 1.73, 0.10 and those of hospital days per admission were 1.29, 0.06. All these statistics were statistically significant and this result provides strong evidence for the existence of small area variations. 2. Comparing patterns of variation among areas, the area which showed higher utilization amounts is Chansungp'o. Koje area, whereas the areas which showed lower utilization amounts are Yongju, Changhung, Miryang, Mokp'o, Koch'ang area. 3. Multivariate analytic methods were used to examine factors related to the variation across areas. In terms of the health resource availability variables, beds per capita or physicians per capita were positively associated with all utilization indices. As for the health service market structure variables, the proportion of health care institutions operating for less than f years was positively related to the expenditure per capita, hospital days per capita and expenditure per admission. In addition the proportion of the private health care institutions also had a negative relationship with total utilization amount and admission rate and the proportion of physicians under age 40 was negatively associated with expenditure per capita and expenditure per admission. With regard to the socio-demographic characteristics, proportion of medicaid population was positively related to hospital days per capita, and percentage of paved road was positively related to hospital days per admission. As a conclusion, wide variations existed across small areas in Korea and supply factors were found to be important in explaining the variation.

• Journal of the Korean Geographical Society
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• v.47 no.3
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• pp.359-374
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• 2012

This paper intends to examine spatial patterns and regional variations of aging population in Korea based on census data for 163 areas during 1980~2010. It briefly investigates general characteristics of aging population in Korea from previous studies and clarifies spatial patterns of aging process at regional level with reference of population growth rate at different time periods. Cities in Korea are classified into several stages including aging society, aged society and super-aged society according to the percentages of aging population out of total population every five years. At the regional scale, the stage of aging society was revealed from 1980, while the stage of aged society was shown from 1995 and super-aged society was entered from 2000 in Korea. Eighty cities in the analysis were shown at the stage of super-aged society in 2010. The portions of aging population are highly related to city size and population growth rate. For instance, the cities both in small size and with low population growth rate are revealing high percentage of aging population. As of 2010, most rural areas are staged into super-aged society, while most cities within Seoul metropolitan area and mid-sized cities are kept in the stage of aging society. At regional scale, there are no significant statistical correlations between total fertility rate and aging population.

• Korean Journal of Ichthyology
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• v.20 no.3
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• pp.179-189
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• 2008

Standard length (SL) and gonadosomatic index (GSI) of Plecoglossus altivelis were investigated from March to October 2007 in Seomjin River and streams flowing to the East Sea, Korea. Water temperatures were $17{\sim}23^{\circ}C$ during the spawning season, which ran from late September to early November in Seomjin River and early August to mid-October in streams flowing to the East Sea. The GSI and HSI variations of ayu population in Seomjin River increased earlier than in populations in streams flowing to the East Sea with similar variation in water temperature. Histological study of ovaries showed that the start of spawning of P. altivelis in Seomjin River was later than in streams flowing to the East Sea. Overall, fecundity increased with increase in SL and not by site specificity. The SL of P. altivelis increased as the river scale increased. Mean length of specimens from Seomjin River (river length: 223.86 km, river area: $4,911.89km^2$) was $194{\pm}15.3mm$, from Osip Stream (55.76 km, $393.78km^2$) $185{\pm}15.5mm$, from Yangyang Namdae Stream (54 km, $474.08km^2$) $142{\pm}11.8mm$, and from Joosoo Stream (21.1 km, $141.47km^2$) $136{\pm}16.7 mm$.

• KOMUNHWA
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• no.68
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• pp.7-24
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• 2006

This article is the critical review of the methods and assumptions with which the Korean archaeologists have tried to approach to the Bronze age society. It was not until the 1980s' that there had been any attempt to define the relevant units for the study of past societies. Before the archaeological records of megalithic builders in the Bronze age began to be analyzed to find out the general traits of chiefdom society, Korean archaeologists had described the variations in the cultural, rather than the social, entities. From the 1990s' , some scholars have attempted to reconstruct the scale and organization of the social groups and explain the growth of polities in evolutionary view, analyzing the hierarchical distributions of settlement data. In the concluding remarks of the review, I would like to indicate the some problems in the conceptualization of the material culture patterning in the regional and/or inter-regional level. First, the conceptual problem which appeared when the Bronze archaeologists define the distribution of artifact assemblages, composed of the specific artifact traits , beyond the instrumental categories that are efficient for the establishments of regional chronologies. It is evidently erroneous conceptualization that we define the artifact assemblages as the socio-cultual entities which came into being in specific time and place, geographically expanded, and finally disappeared based on the view of essentialism. Second, the interpretative problems about wide distributions of certain bronze artifacts must be indicated. I would like to suggest that the wide distributions of the specific bronze dagger or mirror types should be explained not by the cultural area concept related to the ethnicity assumptions, but by the world system or the inter-regional interaction models.