• Journal of The Korean Astronomical Society
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• v.47 no.5
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• pp.167-178
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• 2014

We search for misclassified type 1 AGNs among type 2 AGNs identified with emission line flux ratios, and investigate the properties of the sample. Using 4 113 local type 2 AGNs at 0.02 < z < 0.05 selected from Sloan Digital Sky Survey Data Release 7, we detected a broad component of the $H{\alpha}$ line with a Full-Width at Half-Maximum (FWHM) ranging from 1 700 to $19090km\;s^{-1}$ for 142 objects, based on the spectral decomposition and visual inspection. The fraction of the misclassified type 1 AGNs among type 2 AGN sample is ~3.5%, implying that a large number of missing type 1 AGN population may exist. The misclassified type 1 AGNs have relatively low luminosity with a mean broad $H{\alpha}$ luminosity, log $L_{H\alpha}=40.50{\pm}0.35\;erg\;s^{-1}$, while black hole mass of the sample is comparable to that of the local black hole population, with a mean black hole mass, log $M_{BH}=6.94{\pm}0.51\;M_{\odot}$. The mean Eddington ratio of the sample is log $L_{bol}/L_{Edd}=-2.00{\pm}0.40$, indicating that black hole activity is relatively weak, hence, AGN continuum is too weak to change the host galaxy color. We find that the O III lines show significant velocity offsets, presumably due to outflows in the narrow-line region, while the velocity offset of the narrow component of the $H{\alpha}$ line is not prominent, consistent with the ionized gas kinematics of general type 1 AGN population.

• Journal of the Korean association of regional geographers
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• v.11 no.1
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• pp.83-100
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• 2005

The Seoul Metropolitan Area's economy has undergone structural changes since the 1990s. With recent structural changes in the Korean economy in mind, this paper employs a decomposition analysis of Gross Regional Domestic Product per head and labor productivity to examine how the region's economic performance has changed relative to that of Korea since the 1900s. There are some findings. First, a strong cumulative causation process, derived from industrial linkages and agglomeration effects, has oocurred in the Seoul Metropolitan Area, widening economic disparities between the Seoul Metropolitan Area and the other regions especially since the Korean financial crisis in 1997 mainly due to Gyeonggi province's overwhelming cumulative GRDP growth relative to the national average. Second, the Seoul Metropolitan Area has begun w display good economic performance in terms of labour productivity relative w the national average since the late 1990s, with the region's industrial upgrading being implemented. Finally, manufacturing, financial intermediation and communications have made sensitive contributions to relative Seoul Metropolitan Area's labor productivity growth.

• 한국사회정책
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• v.23 no.1
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• pp.25-59
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• 2016

This paper analyses the policy effect of minimum housing standards, using the fact that Seoul set the minimum housing standards in 1998. Because the whole country except Seoul did not set the minimum housing standards in 1998, we could find this situation as a quasi-experiment. In order to identify the policy effect of minimum housing standards, I compare decreasing amounts in the number of households below the threshold between Seoul and comparison regions from 1995 to 2000, using Differences-in-Differences method. I draw estimate of one-to-one comparison, using Gyeonggi province as a comparison region, and OLS estimate, utilizing the whole nation except Seoul as a comparison region, respectively, and compare two estimates. The former and the latter suggest that the setting of Seoul minimum housing standard in 1998 account for decreasing the number of households under the minimum housing standard, by about 216,638 and 325,149, respectively. The latter is statistically significant at the 0.001 level and the former is in the 95% confidence level of the latter. Therefore we could conclude that the setting of minimum housing standards contributes significantly to achieve the policy objectives, a decrease in the number of households, which are below the threshold.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.3
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• pp.518-527
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• 2016

The housing market is changing continuously according to the place and time and these changes have a ripple effect across various fields. On the other hand, the amount of housing that is consumed in the region also acts as a central cause of price movement. Moreover, the cause of variations in the housing market can be separated according to the characteristics of the housing consumer. In addition, the individual characteristics of the consumer varies according to the region. As a result, a study on the regional causal relationship of the housing market is underway. Although significant research has been done on the domestic home sales market, there has been limited research on the housing charter market. Therefore, in this paper, regional causal relationship of the housing market in the Gangnam and Gangbuk area in Seoul and Gyeonggi Province was analyzed using the vector error correction model, and is segmented by housing sale market and housing jeonse market. In addition, housing sale and housing jeonse of Gangam, Ganbuk and Gyeonggi province are defined as analysis variables, and time series data is the monthly material of June 2003 to November 2015. The results of the analysis, in the case of the housing sale market, showed that fluctuations in house prices in Gangnam area have a major influence on the fluctuations in house prices in the surrounding region. Similarly, in the case of the housing jeonse market, it was found that the jeonse price of Gangnam area has a significant impact on the jeonse price of housing in the surrounding area.

• Korean Journal of Community Nutrition
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• v.22 no.2
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• pp.145-158
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• 2017

Objectives: The importance of kimchi as a traditional food in Korean cuisine has gradually decreased due to rapid industrialization, economic growth and changes in dietary patterns in Korea. This study aimed to examine the shifts in kimchi consumption by region and by income level between 2005 and 2015 in Korea. Methods: Data from the Korea National Health and Nutrition Examination Surveys III (2005) and VI (2015) were used in the study (n=15,558). Intake of kimchi was estimated using a single 24-hour dietary recall. The sample weights were applied in all analyses to reflect population estimates. All statistical analyses were carried out by using SPSS IBM Statistics 20. Results: Kimchi intake has significantly decreased by 27.6 g/day per capita during the last decade in Korea; 25.0 g for males and 29.9 g for females, respectively. Over the past decade, the decline of kimchi intake has been particularly significant in Seoul, Busan, Incheon, Gyeonggi, and Gwangju, while there has been no significant change in males living in rural areas. The consumption of kimchi across all income levels has decreased, however, the decrease was higher in 'middle and low income level'. The amount of kimchi consumption in 2015 was the highest in 'low income level'. The results were similar after adjusting for gender and age. Conclusions: For the past decade, the overall intake of kimchi in Korea has decreased, however, it has been found that the decrease of kimchi intake for males living in the rural areas was not significant. Therefore, in order to keep our traditional kimchi culture and promote a balanced diet including kimchi for Korean, it is necessary to develop more efficient policies and approaches. A variety of dishes using kimchi should be developed, besides merely serving kimchi with rice as a side dish, to increase the consumption of kimchi.

• Journal of the Economic Geographical Society of Korea
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• v.24 no.3
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• pp.259-282
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• 2021

This study analyzes actor networks in regional innovation processes with a focus on actors' activities and finds the determinants of the networks, thereby aiming to provide information useful for regional innovation policy makers. To this end, the study conducted a social network analysis of the national R&D projects data and identified the activities of innovation actors. Finding out the network determinants was QAP analysis. The study suggests three main findings as follows. First, a meaningful difference exists in characteristics of innovation activity by region. Second, the network of innovation actors meaningfully differs from region to region. The centrality of the network was found to be high in universities and businesses in Seoul and Gyeonggi, and in public research institutes in Daejeon. There are regions where all the networks of innovative actors are composed of one component, while some regions are not yet established with the network. Finally, although the networks of innovation actors are influenced by the geographical proximity and the size of the R&D fund, it is notable that the previous continuous relationship forms a strong research network.

• Journal of the Korea Society for Simulation
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• v.30 no.3
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• pp.19-29
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• 2021

To explain the interregional infections in COVID-19, we designed a multi-group compartmental model by applying the SEIQRD model, a compartmental model of a single group. The model is segmented by compartments to account for hidden infections, such as latent periods and asymptomatic cases, and is capable of comparing infection indices and test rates between regions. Through this, it estimated which region was centered during the second wave in August 2020 and the third wave in November 2020. Subgroups were set up in Seoul, Gyeonggi (including Incheon), and a non-metropolitan area. We fit the model to the Ministry of Health and Welfare's data to estimate the average infection index between regions, average rate of rT-PCR test by region, and the expected number of hidden infections by region.

• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.5
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• pp.1-15
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• 2017

In this study, we visualized the regional migration in Korea from 2001 to 2015 using the Chord diagram which can represents amount of migration and flows at the same time. In addition, we constructed a migration network and analyzed the degree centrality of each region for identifying the main regions linking to various regions. In 2001~2005, most of population moved into Geonggi from various regions. However, the capital function was transferred to Sejong in 2011~2015, and population moving into Sejong and Chungnam was increased significantly. The main outflow of population in migration network were shown at the regions in Jeonbuk and Gyeongbuk province in 2001~2004, and recently the regions in Gyeongnam, Gyeonggi, and Seoul were identified as the main nodes in terms of outflow of population. We also focused on migration in rural area through degree centrality, and cord diagram in Chungnam, Jeonbuk, and Jeonnam where include the representative crop area. In 2015. there was the significant increase of migration from Gyeonggi to Chungnam, and internal migration within Jeonbuk increased rather than cross-border migration. In addition, migration from Jeonam to capital area decreased in 2015 but migration among cities within Jeonman increased. In particular, Yesan-gun showed the significant migration to other cities in Jeonnam. Population is necessary to develop community and sustain economic growth in rural regions. Therefore, migration is important for the transfer of manpower. The strength of this study is to approach the temporal change of migration from the viewpoint on quantitative and structural characteristics.

• Korean Security Journal
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• no.51
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• pp.293-313
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• 2017

The purpose of this study is to analyze the changes of regional clusters of national 16 areas on the assembly & demonstration in 2010 and 2015. The results of this study were as follows by using hierarchical cluster analysis. First, the regional clusters on the assembly & demonstration in 2010 were divided into three clusters in the first step: (1) Gwangju, Chungnam, Incheon, Chungbuk, Gyeongbuk, Daegu, Gangwon, Jeju, Daejeon, (2) Jeonnam, Gyeongnam, Busan, Jeonbuk, Ulsan, Gyeonggi, (3) Seoul. Second, the regional clusters on the assembly & demonstration in 2015 were divided into three clusters in the first step: (1) Ulsan, Gangwon, Chungbuk, Chungnam, Incheon, Gyeongbuk, Jeonnam, Gwangju, Jeju, Daegu, Daejeon, (2) Busan, Jeonbuk, Gyeongnam, (3) Seoul, Gyunggi. Third, The regional clusters on the assembly & demonstration were Busan, Jeonbuk, Gyeongnam of 'assembly & demonstration management area(labor related)', and Seoul, Gyeonggi of 'assembly & demonstration frequency areas' in 2015. This suggests that policing policies related to assembly & demonstration can be established and implemented flexibly in consideration of the degree of increase and decrease in assembly & demonstration by districts. Furthermore, it will be helpful to manage assembly & demonstration based on the 'police for human rights'.

• Korean Journal of Heritage: History & Science
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• v.56 no.3
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• pp.22-44
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• 2023

The subsistence economics of the early Bronze Age has focused on explaining the intensity of agricultural practices without sufficiently taking into account the diversity of production methods that may arise from cultural types or environmental factors. The problem appears to stem from paying insufficient attention to the question whether we should understand the transition from the Neolithic Age to the Bronze Age as continuous or discrete. This has hitherto blocked an avenue to investigate the gradual changes in subsistence resource production methods. Taking as its premise that changes in the production methods of subsistence resources in the Bronze Age have been continuous and gradual, this paper seeks to restore the production patterns of subsistence resources according to the variety of factors that may have influenced the early Bronze Age production method. With diverse cultural patterns and ecological spaces of the early Bronze Age being confirmed, the work of restoring the production methods of subsistence resources in a specific period is difficult to achieve with one or two stand-alone analyses. A more appropriate method would involve separating a number of different aspects related to the production of subsistence resources, analyzing and interpreting each, and in the final stage, synthesizing the analyses. The specific research method employed in this paper checked for compositional differences in stone production tools, functionally categorized according to a variety of factors that have a close relationship with the production of subsistence resources: cultural-environmental factors and cultural patterns, geographical and topographical factors, soil productivity, and size of settlement. The results of the analysis are as follows: for the early Bronze Age production pattern of subsistence resources in the Seoul and Gyeonggi regions, while no substantive differences were observed with respect to cultural type, geographical and topographical location, the results show statistically significant differences in the composition of production tools according to settlement size and soil productivity. Also, with an increasing ratio of settlement size and total production soil, increases in hunting and armoring tools, woodworking tools, and harvesting tools were observed; on the other hand, when it came to the ratio of fishing tools, the opposite relationship was observed. While a correlation between settlement size or crop cultivation productivity and dependence on hunting or farming was expected, the results of the regression analysis show that settlement size and soil productivity ratios do not have mutually significant relationships. The results thus illustrate that patterns of production differ according to a variety of factors, and no single factor is decisive in the adoption of subsistence resource production methods by a specific settlement. Therefore, the paper emphasizes the need to investigate the production patterns of subsistence resources according to the variety of cultural and environmental factors that make up settlements in early Bronze Age society.