• Journal of Distribution Science
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• v.12 no.3
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• pp.65-73
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• 2014

Purpose - Aging and fewer economically active people have challenged the assumption of continuous population increases. A new real estate valuation methodology reflecting changes in population structure is thus needed. Research design, data, and methodology - The relationship between demographic change and changes in real estate prices is analyzed using ordinary least squares (OLS) to estimate the parameters, and a population structure change (PSC)-Binomial Option Model is developed to assess the volatility of the estimated parameters. Results based on Seoul and Shanghai data are compared. Results - Results of the DCF method indicate that investing in Seoul is better than investing in Shanghai, but the binomial option indicates the opposite. The PSC-binomial option model, reflecting changes in population structure, yields higher values (24.6 million won in Seoul and 43.3 million won in Shanghai) than those given by the binomial option model. Conclusions - This study indicates that applying changes in population structure to existing research, such as in the binomial option model, represents a more accurate real estate valuation method. Results demonstrate that the new model is more accurate than existing models such as the DCF or binomial option.

• Journal of Korean Society of Rural Planning
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• v.29 no.3
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• pp.91-97
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• 2023

The purpose of this research is to apply the regional development attractiveness of the national level determined in the previous study to the city and county level of Chungcheongnam-do. We verified results with the population change of the floating population data. In order to measure regional development attractiveness in 2020, Chungcheongnam-do's integrated air environment index and per capita gross regional product were gathered. Population movement data over the past five years have been used to analyze population changes in the floating population data. Regional development attractiveness depended on the data of GDP per capita, which had a large difference between the maximum and minimum values. The rate of increase or decrease in population change by city and county in Chungcheongnam-do over the past five years has changed significantly since 2021 and characteristics of each group were grouped into four groups. Based on the environment and economic feasibility of the region, it can be the starting point for a new analysis of Korea's regional development projects and the selection of target sites. Policy suggestions can also be made in spatial plans such as short-term comprehensive plans, long-term comprehensive plans, and development plans. It can be a limit of this research that regional development attractiveness was determined by the relatively large per capita gross domestic product. It is necessary to further develop regional development attractiveness by closely investigating the characteristics of the region, social problems, and emissions of environmentally harmful substances.

• Communications for Statistical Applications and Methods
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• v.22 no.1
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• pp.15-18
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• 2015

Reunification, (considered a 'bonanza'), is often expected to bring economic and social benefits as well as solutions to the population aging problem; consequently, the study on the population structure of North Korea is salient. This paper reviews and talks on the North Korean population and implications. In view of reliability and consistency, the North Korean population appears at an explicit change compared to the past, and shows significant differences from the South, implying that it needs significant resources to integrate during reunification. Therefore, it is opportune to discuss the North Korean population prior to the clamor for the reunification.

• Korea journal of population studies
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• v.8 no.1
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• pp.20-46
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• 1985

The increase of the population has an effect on the increase of students. The high birthrate, which means the extension of enrollments in the future, requires preparation of enough facilities and equipment for education. However, the educational conditions of Korea are not yet developed, and in such a situation the increase of enrollments makes the improvement of educational conditions difficult. Besides, the influx of students into the large cities has made complex educational problems such as a decrease of students in the rural area and a change for the worse of the educational conditions in the urban area. For the development of education in such a situation, an emphasis should be put not only on security of a stable educational finance but also on activation of family planning project and curb of population influx into large cities in the realm of population policy. In addition, population education for the youth should be strengthened in order that they can have sound view of family life, married life, children, and sex moral. For the way the young married live has relationship with the number and quality of children in the future of our nation.

• Korean Journal of Organic Agriculture
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• v.15 no.3
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• pp.291-307
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• 2007

The objective of this article is to examine the structure of the composition of the population in rural area for the last 45 years, and to forecast mid and long term structure of the population in the near future. Moreover, forecast has been done whether the rapid increase by the inflow of foreigners has any offset on the structural change in rural population. According to the research result, the rural area is experiencing a rapid decrease in population, a rapid increase in the percentage of the aged, and foreigners. To resolve the problematic situation mentioned above, some effective counterplan has to be considered by all agencies concerned.

• Journal of the Korean Association of Geographic Information Studies
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• v.26 no.4
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• pp.97-115
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• 2023

In recent years, the structure of the population has been changing rapidly, with a declining birthrate and aging population, and the inequality of population distribution is expanding. At this point, changes in population estimation methods are required, and more accurate estimates are needed at the subregional level. This study aims to estimate the population in 2040 at the 500m grid level by applying an explainable machine learning to Busan in order to respond to this need for a change in population estimation method. Comparing the results of population estimation by applying the explainable machine learning and the cohort component method, we found that the machine learning produces lower errors and is more applicable to estimating areas with large population changes. This is because machine learning can account for a combination of variables that are likely to affect demographic change. Overestimated population values in a declining population period are likely to cause problems in urban planning, such as inefficiency of investment and overinvestment in certain sectors, resulting in a decrease in quality in other sectors. Underestimated population values can also accelerate the shrinkage of cities and reduce the quality of life, so there is a need to develop appropriate population estimation methods and alternatives.

• Journal of Marine Life Science
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• v.9 no.1
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• pp.41-46
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• 2024

This study aimed to reconfirm the sex change scale and pattern of Tegillarca granosa. Although the sex ratio (female : male, female proportion) of T. granosa was 1:2.32 (30.2%) at the initial stage (2011) of the study, it was 1:0.94 (51.5%) after one year (2012) in the same population. The increase of the female proportion was greater in the 2+ year class (23.0%) when compared to the 1+ year class (19.2%). Overall, sex change ratio of 37.6% was observed in this population of T. granosa. The sex change ratio of the 2+ year class (39.3%) was higher than that of the 1+ year class (35.3%). And sex change ratio in the males (42.2%) was higher than that in the females (26.9%). The female proportion was the opposite of the result from 2006~2007, and one of the causes was presumed to be the difference in cumulative water temperature during the gonadal inactive stage (winter).

• The Journal of Korean Medicine
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• v.32 no.5
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• pp.41-49
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• 2011

Objectives: To optimize the preservation method of herbal decoction, we investigated the content of principle components of Pyungwi-san, liquiritin, glycyrrhizin, and hesperidin according to preservation temperature and period. We also investigated the changing patterns of pH and microbial population in Pyungwi-san decoction as a model case. Methods: With samples preserved at different temperatures, the content of liquiritin, glycyrrhizin, and hesperidin was determined using HPLC and microbial population was determined as viable counting method up to 8 times every month. Identification of isolated bacteria was performed by 16S rDNA analysis. Results: The content of liquiritin and glycyrrhizin did not change according to the preservation temperature and period, but that of hesperidin was severely decreased at room temperature. The isolate from the decoction was identified as Bacillus licheniformis by 16S rDNA sequence analysis. Microbial population appeared after 3 months' preservation and reached maximum value at 4 months; at all tested temperatures, the pH showed the lowest value (4.4-4.5) simultaneously. Conclusion: From the results, it seems to be that the microbial growth affects the pH of preserved decoction but not the change of liquiritin and glycyrrhizin content.

• Journal of Environmental Science International
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• v.14 no.4
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• pp.367-371
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• 2005

Soil samples were collected from new-developed wetland soil ecosystem of Tamarix chinesis plantation in Chinese Yellow River Delta in different months of 2003. Soil characteristics, temporal change and spatial distribution of microbial community composition and their relationship with nitrogen turnover and circling were investigated in order to analyze and characterize the role of microbial diversity and functioning in the specific soil ecosystem. The result showed that the total population of microbial community in the studied soil was considerably low, compared with common natural ecosystem. The amount of microorganism followed as the order: bacteria> actinomycetes>fungi. Amount of actinomycetes were higher by far than that of fungi. Microbial population remarkably varied in different months. Microbial population of three species in top horizon was corrected to that in deep horizon. Obvious rhizosphere effect was observed and microbial population was significantly higher in rhizosphere than other soils due to vegetation growth, root exudation, and cumulative dead fine roots. Our results demonstrate that microbial diversity is low, while is dominated by specific community in the wetland ecosystem of Tamarix chinesi.

• ALGAE
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• v.37 no.2
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• pp.85-103
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• 2022

Korea is one of the most advanced countries in kelp aquaculture. The brown algae, Undaria pinnatifida and Saccharina japonica are major aquaculture species and have been principally utilized for human food and abalone feed in Korea. This review discusses the diversity, population structure and genomics of kelps. In addition, we have introduced new cultivar development efforts considering climate change, and potential carbon sequestration of kelp aquaculture in Korea. U. pinnatifida showed high diversity within the natural populations but reduced genetic diversity in cultivars. However, very few studies of S. japonica have been conducted in terms of population structure. Since studies on cultivar development began in early 2000s, five U. pinnatifida and one S. japonica varieties have been registered to the International Union for the Protection of New Varieties of Plants (UPOV). To meet the demands for seaweed biomass in various industries, more cultivars should be developed with specific traits to meet application demands. Additionally, cultivation technologies should be diversified, such as integrated multi-trophic aquaculture (IMTA) and offshore aquaculture, to achieve environmental and economic sustainability. These kelps are anticipated to be important sources of blue carbon in Korea.