• 토지주택연구
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• 제9권3호
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• pp.29-36
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• 2018

This study aims at suggesting directions to make children's parks considering the actual groups using them by comparative analysis of age distribution in residents within area of use and locations of children's parks with regards to changes in population structure of low birth rate and aging. Cheongju was selected for the study, and the current status of children's parks and population structure were categorized into six stages and the investigation and analysis were conducted by statistics by population group and by using Arc GIS Program. As a result of the analysis, children under 13 were 13.1% of the entire population in Cheongju and share of middle-aged and aged group including middle-aged was 31.3%. Park area per one children under 13 was 5.9㎡ and based on walking use area(250m), average number of parks available by autonomous district was eight. As a result of the analysis of characteristics of distribution of children's parks, they are densely located in old downtowns or the distribution density was relatively high in newly developed areas such as Osong-eup or Ochang-eup. However, outer rural areas have no children's parks or relatively low rate. As a result of the analysis on population structure and co-efficient of park location, in nine autonomous districts, aged group is increasing, leading to decrease use of children's parks. If resident rate aged group is higher in the region where a children's park is located, it is necessary to re-compose the existing one to different one or to change purposes of parks to be planned. Also, in the area with similar rates in both children's group and aged group, composing complex parks for both of them could be considered. This study has limitations by not conducting field studies about the current status of use of children's parks in areas where the population structure has been changing and not suggesting specifically new types of parks according to changes in population structure. It is necessary to conduct the following studies about relationship between children's parks and policies for composing parks responding to changes in population structure in neighboring regions in future.

• 유통과학연구
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• 제12권3호
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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 Forest and Environmental Science
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• 제31권3호
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• pp.164-176
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• 2015

Cyathea gigantea is a tree fern distributed throughout humid tropical regions of northeast India and other parts of the country. However, wild populations of this species are largely affected by various natural and anthropogenic activities. Therefore, an attempt was made to study the population structure and regeneration status of C. gigantea in and around greater Itanagar area of Papum Pare district, Arunachal Pradesh. Altogether 45 patches, ranging from 19.63 to $260m^2$ of area, were randomly sampled to study population structure and regeneration status of the species. Population study showed highest number of youngs in the height class of 0.50-0.75 m while, immatures were recorded highest in the height class of 2.0 to 2.5 m. Majority of the matures belonged to 6-9 m height class while it was recorded maximum in the diameter class of 10-15 cm. Average density of C. gigantea was $0.07individuals\;ha^{-1}$ which varied greatly among different patches with a range of 2 to 14. Significant correlations were found between patch size and density of youngs, immatures, matures and total density. Maximum concentration of youngs was observed in patch size $60-140m^2$, while for immatures, it was highest in patch size $20-160m^2$. Similarly, highest concentration of matures was observed in patch size $20-80m^2$ and $80-180m^2$. Population structure of the total population exhibited inverted pyramid shaped distribution. Population structure consisting of youngs, immatures, matures showed that around 60% patches lack of regenerating individuals which depict very poor natural regeneration of the species. Effective conservation strategies are therefore to be formulated to save C. gigantea from the threat of extinction in near future.

• 한국경제지리학회지
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• 제16권3호
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• pp.445-457
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• 2013

본 논문의 목적은 우리나라 도시공간구조 변화를 시계열적으로 분석하고, 지역별 규모별 그 특성을 도출하는 것이다. 본 논문에서 도시공간구조는 인구밀도경사함수(population gradient curve)를 통해 분석하였고, 분석의 시간적 범위는 자료구축의 가능성을 고려하여 2000년부터 2010년까지로 설정하였으며, 공간적 범위는 광역시를 제외한 70개 도시이다. 본 논문의 분석결과를 요약하면 다음과 같다. 첫째, 우리나라 도시들은 평균적으로 도심 인구밀도는 감소하고, 인구밀도 경사도는 완만해져 도심 집중현상보다 외곽지역으로의 확산이 활발하게 진행되는 것으로 나타났다. 둘째, 비수도권 지역은 전국 평균과 동일한 형태의 공간구조 변화를 경험하였지만, 수도권 지역은 외곽지역뿐만 아니라 도심까지 인구밀도가 함께 높아지는 현상이 나타났다. 셋째, 인구 20만 이상의 중도시와 대도시에서는 도심 집중현상보다는 도시 외곽지역으로의 확산이 우세하게 나타난 반면, 인구 20만 미만의 소도시에서는 도심 인구밀도가 높아지면서 인구밀도 경사도의 절댓값이 커지는 도심 집중현상, 즉 압축도시의 특성이 나타나는 것으로 분석되었다.

• ALGAE
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• 제24권1호
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• pp.31-38
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• 2009

The brown algae padina concrescens is widely distributed in the northwestern Pacific Mexico. We described the population of P. concrescens based on population parameters such as cover, density and size structure and reproduc-tion at two levels tide at the intertidal area in the southwestern Baja. California Peninsula. Monthly visits from January to December 2003 were done. Both cover and density were measured in situ by quadrants method. Samples were collected to obtain size structure and percentage of reproductive fronds. Our results show there is sparial vari-ation in the population structure more than temporal. Thus, cover and density peak were at different months ineach tide level studied, the lower tide level shows the high values in cover as well as density. The frond develop-ment was observed in height/width ratio this relation was consistent only in the low tidal zone. Size class distribu-tion has consistently small size plants in both tide levels.Reproduction was seasonal in the tide channel but in both tide levels all the reproductive plants were tetrasporophyte. Our results suggest that this population is pseudopere-nial and it strongly as a consequence of the intense competition in the intertidal zone.

• Journal of Species Research
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• 제7권4호
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• pp.354-362
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• 2018

Population genetic assessment is essential for the conservation and management of endangered and rare plants. Neofinetia falcata is endangered epiphyte orchid and protected by law in Korea. In Korea, this species is only found on islands in the South Sea of Korea (including Jeju-do) and the southern coast of the Korean Peninsula. We developed nine microsatellite makers to assess the genetic diversity and population genetic structure of three populations of N. falcata. The genetic diversity at the species level was low, which can be attributed to inbreeding or fragmentation into small, isolated populations. A recent bottleneck was detected in one population, likely due to overcollection. N. falcata exhibited moderated levels of differentiation among populations, with the three populations were divided into two clusters based on genetic structure. The genetic diversity and structure of N. falcata are affected by restricted gene flow by pollen or seeds due to isolation and geographic distance. Strategies for in situ and ex situ conservation of this species are been proposed based on the results of our study.

• The Korean Journal of Ecology
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• 제17권4호
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• pp.453-461
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• 1994

Size class structure and vegetative growth of a perennial herb of the temperate deciduous forests, Symplocarpus renifolius Schott, were studied from 1991 to 1994 in Namhansansung, Kyonggi Province, Korea. The size class structures of leaf number and leaf area per individual followed bell-shape curve, i.e. frequency of middle class was relatively high. The leaf area increased from the late-March to mid-May. At the end of the growing season, leaf area(length X breadth) was proportional to biomass, especially aboveground biomass. The leaf number and leaf area per individual increased at the rate of 0.08 leaf/year and 9.7 $cm^2/year$, respectively. The size of the individuals in large-sized classes, in leaf number and leaf area, decreased in next year, while the size of the individuals in small-sized classes increased. Therefore, it was concluded that the size class structure of S. renifolius population was largely determined by the growth form.

• 한국지리정보학회지
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• 제9권4호
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• pp.204-214
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• 2006

부산대도시의 공간구조와 그 문제들에 관심을 가진 많은 도시 학자들과 연구자들이 부산대도시 공간구조에 대한 관리의 필요성을 오랫동안 제기하였다. 그래서 본 연구의 목적은 1993년, 2001년의 기간 동안의 인구밀도, 고용밀도, 지가로 부산대도시의 공간구조의 동적인 변화를 알아보는 것이다. 본 연구의 중요한 결과들은 다음과 같다. 도심의 인구유출을 경험하는 동안, 주변부는 지속적으로 성장하였다. 중앙동은 인구 잠재성의 높은 접근성을 가졌다. 그러나 그 접근성은 1993년 이후 줄어들고 있다. 부전동은 2000년까지 인구가 증가하는 경향을 보이나 그 이후 년부터는 인구가 감소하였다. 그사이에 주변부는 높은 접근성으로 인구가 증가하였다. 그래서 부산의 공간구조가 다핵도시로 바뀌었다. 이 현상은 기존의 도심에서부터 자발적인 인구분산을 일으키게 되었다. 지가 변화에서는 부산 도시화의 분포패턴을 보여준다. 부산의 가장 높은 지가는 CBD에서 나타나며, 부산의 발전은 남북 띠를 따라 나아가면서, 서부산 지역에 영향을 주었다.

• 한국시스템다이내믹스연구
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• 제13권4호
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• pp.5-31
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• 2012

This paper aims at investigating the dynamics between aging population and local finance. In recent years, the aging rate has been accelerating the pace. The trend implies that Korea is moving towards the aging society, presumably, with unprecedented speed in the world. Aging society's biggest problems are centered around the explosive growth of the financial needs. In particular, these problems are apt to appear more seriously in local governments, as most of them are confronted with high level of aging population and poor financial bases. Firstly, it analyzes how the population structure in the local government impacts local finance, income and expenditure. Based upon in-depth literature reviews, this study examines variables related to aging population and local fiance. Secondly, it focuses on a series of positive and negative feedback loops which would reveal the essence of the mutual interaction structure between aging population and local governments' fiscal behaviors.

• Animal Bioscience
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• 제34권5호
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• pp.789-800
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• 2021

Objective: Conservation and genetic improvement of cattle breeds require information about genetic diversity and population structure of the cattle. In this study, we investigated the genetic diversity and population structure of the three cattle breeds in the Korean peninsula. Methods: Jeju Black, Hanwoo, Holstein cattle in Korea, together with six foreign breeds were examined. Genetic diversity within the cattle breeds was analyzed with minor allele frequency (MAF), observed and expected heterozygosity (HO and HE), inbreeding coefficient (FIS) and past effective population size. Molecular variance and population structure between the nine breeds were analyzed using a model-based clustering method. Genetic distances between breeds were evaluated with Nei's genetic distance and Weir and Cockerham's FST. Results: Our results revealed that Jeju Black cattle had lowest level of heterozygosity (HE = 0.21) among the studied taurine breeds, and an average MAF of 0.16. The level of inbreeding was -0.076 for Jeju Black, while -0.018 to -0.118 for the other breeds. Principle component analysis and neighbor-joining tree showed a clear separation of Jeju Black cattle from other local (Hanwoo and Japanese cattle) and taurine/indicine cattle breeds in evolutionary process, and a distinct pattern of admixture of Jeju Black cattle having no clustering with other studied populations. The FST value between Jeju Black cattle and Hanwoo was 0.106, which was lowest across the pair of breeds ranging from 0.161 to 0.274, indicating some degree of genetic closeness of Jeju Black cattle with Hanwoo. The past effective population size of Jeju Black cattle was very small, i.e. 38 in 13 generation ago, whereas 209 for Hanwoo. Conclusion: This study indicates genetic uniqueness of Jeju Black cattle. However, a small effective population size of Jeju Black cattle indicates the requirement for an implementation of a sustainable breeding policy to increase the population for genetic improvement and future conservation.