• 한국지하수토양환경학회지:지하수토양환경
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• 제20권7호
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• pp.121-134
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• 2015

Spatial and temporal changes in algal population in Yongdam reservoir and ecological factors that induced the changes in the size and composition of algal population were investigated by monthly sampling at ten locations in the reservoir. Nutritional state of the reservoir was identified to be phosphorus-limited with nitrogen to phosphorus (N : P) ratio much greater than 17 in most samples. Algal population was dominated by three taxonomic groups, diatoms, chlorophytes and cyanobacteria. Although explosive algal growth was not observed in the summer, algal population showed transition with time of the dominant algal type from diatoms in the winter to cyanobacteria in the summer. Chlorophyta was not the dominant group in the reservoir although they maintained relatively stable number of cells in the reservoir and showed increase in population from March to May. The application of statistical methods revealed that the factors inducing changes in cell number of each group were water temperature for diatoms and cyanobacteria and phosphorus concentration for chlorophyte. Fluctuation of cyanobacterial population was mainly observed near the inlet of tributaries while diatoms showed higher variation inside the reservoir.

• 한국인구학
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• 제29권1호
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• pp.241-268
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• 2006

본 연구는 출산율이 세계 최저수준으로 낮아진 한국사회의 적정인구를 사회복지적 관점에서 논의한다. 이는 인구규모의 급격한 감소와 인구구조외 불균형이 예측되어 결과적으로 국가발전에 부정적인 영향을 줄 것으로 전망되기 때문이다. 사회복지적 측면에서의 적정인구는 1인당 복지수준 또는 사회전체의 복지수준, 곧 사회적 후생(social welfare)의 크기 또는 복지성장률이 극대화되는 지점이다. 적정 인구구조는 전체인구대비 노인인구 약 $15{\sim}17%$, 생산인구 약 $64{\sim}69%$, 그리고 고령화지수 약 $72{\sim}104$ 수준이다. 또한 현재의 인구규모 및 인구구조를 감안한 한국의 적정 인구규모는 약 $4,850{\sim}4,950$만 명인 것으로 나타났다. 따라서 저출산의 원인제거로 출산율을 회복하여야 함과 동시에 외국인력을 유입할 수 있는 준비를 갖추어야 할 것이다. 아울러 아동들이 좋은 환경에서 성장할 수 있도록 노력하고 여성과 노인이 노동시장에 참여할 수 있는 조건을 제공하여야 할 필요가 있다.

• Asian-Australasian Journal of Animal Sciences
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• 제32권6호
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• pp.815-825
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• 2019

Objective: To effectively use corn stover resources as animal feed, the changes in microbial population and chemical composition of corn stover during field exposure, and their silage fermentation and in vitro digestibility were studied. Methods: Corn cultivars (Jintian, Jinnuo, and Xianyu) stovers from 4 random sections of the field were harvested at the preliminary dough stage of maturity on September 2, 2015. The corn stover exposed in the field for 0, 7, 15, 30, 60, 90, and 180 d, and their silages at 60 d of ensiling were used for the analysis of microbial population, chemical composition, fermentation quality, and in vitro digestibility. Data were analyzed with a completely randomized $3{\times}6$ [corn stover cultivar $(C){\times}exposure$ d (D)] factorial treatment design. Analysis of variance was performed using SAS ver. 9.0 software (SAS Institute Inc., Cary, NC, USA). Results: Aerobic bacteria were dominant population in fresh corn stover. After ensiling, the lactic acid bacteria (LAB) became the dominant bacteria, while other microbes decreased or dropped below the detection level. The crude protein (CP) and water-soluble carbohydrate (WSC) for fresh stover were 6.74% to 9.51% and 11.75% to 13.21% on a dry matter basis, respectively. After exposure, the CP and WSC contents decreased greatly. Fresh stover had a relatively low dry matter while high WSC content and LAB counts, producing silage of good quality, but the dry stover did not. Silage fermentation inhibited nutrient loss and improved the fermentation quality and in vitro digestibility. Conclusion: The results confirm that fresh corn stover has good ensiling characteristics and that it can produce silage of good quality.

• 한국약용작물학회지
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• 제10권4호
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• pp.298-302
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• 2002

The essential oils were isolated by hydrodistillation and their composition determined capillary GC method with standards. The essential oil content showed significant differences between the two populations on the vegetative organs. The essential oil level of the leaves and roots was considerably higher in the Korean population at full flowering and waxy ripening stage but essential oil content of the roots was significantly higher in the Hungarian taxon at leaf rosette stage. We observed the essential oil accumulation tendency was mianly dependent on plant organs and intra-specific taxon during the vegeation period. Butylidene-phthalide was proved to be the main component of the oil in both population roots (50.9-73.3%), while dimethyl-acetate was showed as a major compound on the over-ground parts (56.7-62.0%). The qualitative composition of the essential oil in the reproductive organs concerning the identified compounds was the same as the vegetative parts with the main component ${\alpha}-phellandrene$ (4.8-28.1%) and butylidene-phtalide (9.7-16.1%), The quantitative composition showed some changes during the ontogenesis phases. Most characteristic ones are the decreasing proportion of dimethyl-acetate (from 7.3% to 1.1%) and the appearance of ${\alpha}-pinene$ (from 0.5% to 1.5%) only after fruit setting in both population.

• 한국응용곤충학회지
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• 제32권2호
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• pp.168-175
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• 1993

This study investigated the composition and distribution of the soil microarthropods community in plantations of the Korean pine(Pinus Koraiensis SIEB. et ZUCC, the sudong area, Namyangju-gun, Korea) , which had been planted in different years. The soil samples intended to collect soil animals were taken monthly from June 1988 to July 1989. The composition of soil microarthropods community included Arachnida, Chilopoda, Insecta, Collembola, Diplopoda, Crustacea, and Symphyla. The Acarina were composed of 82.4% of Cryptostigmata, 8.0% of Mesostigmata, 7.9% of nymphs, and 1.7% of others. The Insecta included six orders including Hymenoptera(65.8%) and Diptera(13.9%). Population densities increased from when the plantations were first established until the planting were 25 years old, after which they declined. Population densities of the soil microarthropods were highest in July and lowest in January. The Collembola/Acarina ratio is 0.16 overall, and was highest in January and lowest in August.

• 한국환경복원기술학회지
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• 제17권1호
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• pp.147-162
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• 2014

This study aims to provide the biological and geographical materials to identify the changes in population of Family Ardeidae included Egretta alba modesta, Egretta garzetta, Bubulcus ibis, and Nycticorax nycticorax and establish their conservation measurement in terms of the fragmented and deteriorated habitat by human development such as housing and park projects. Wonjucheon Stream was measured the highest species diversity since the survey site was relatively less interfered by the surrounding human beings showing lower disturbance elements. However, the closer the stream comes downstream, the more the artificial disturbance elements generate, confirming that the species better adapted to contamination grow in more density so that the species composition becomes simplified. It implies that feeding place as well as breeding-growing places is also more closely related to the changes in population structure and species composition of Family Ardeidae. The results of Family Ardeidae immigration in Taejang-dong, Wonju, among the other survey sites, revealed that a total of 231 came to the site in 2006; and 210 in 2011, showing more or less reduction in the population. In the mean while, Namyang-dong in Hwaseong City showed the continuous decrease in population number of Family Ardeidae with 135 before development and 60 during development, resulting in the number never growing but continuously narrowing over and over after development. As a result of surveying the number of Family Ardeidae that bred following the findings above, Taejang-dong in Wonju City had 4 species of Family Ardeidae being bred, however, showing the decrease in number of population from 998 in 2006 to 589 in 2011. Namyang-dong in Hwaseong was confirmed to have as many as 352 of the population in 2006 and 230 in 2008; after the deforestation on their habitat, they had not lived in the site any longer, suggesting that the development would significantly affect Family Ardeidae.

• 한국인구학
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• 제9권1호
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• pp.69-88
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• 1986

The purpose of the present study is to find out and analyze the degree of population concentration of 10 selected cities. The data used for the present study were derived from the Government publications including the population and Housing Census Reports from 1966 through 1980 and the Korea Urbanic Yearbooks from 1969 through 1981. The major findings of the study were summarized as follows: The data revealed that changes of population size were more rapidly proceeded in Seoul than any other city and regarding to population composition, these selected cities had more male population than female population. The proportion of the productive age group of these selected cities were found to be higher than that of whole country each year, especially the proportion 20∼24 aged group was higher in 1980 than any other year. The number of net migrants in these cities during last 20 years, 1960∼80 was 910, 656 as Seoul obtained the largest net migrants and among the selected cities, Seoul, Busan, Daegu, Incheon, Daejeon and Jeonju had a big change in volume of net migration population, especially in 30∼39 aged group in 1980. According to Gini Concentration Ratio and Index of Concentration, the population concentration was the highest in 1980 and the population concentration was intensively accelerated during 1966∼ 1970.

• 한국산림과학회지
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• 제99권5호
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• pp.762-769
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• 2010

The composition of minerals and amino acids in Allium victorialis var. platyphyllum tissues collected from different habitats in Ulleung Island and Mt. Hambeak of the Korean Peninsula is investigated. The mineral composition of A. victorialis stem was high compared to that of bulb in all population samples. The most abundant mineral found in all the samples was potassium (K). The mineral composition was variable in garlic population of Ulleung Island in a habitat dependent manner. The A. victorialis stems and bulbs showed significant differences in their amino acid compositions according to varying habitats of Ulleung Island and Mt. Hambeak. Among the amino acids the most abundant amino acid in A. victorialis bulb tissue was arginine, followed by leucine and valine. The amino acids leucine, valine, and phenylalanine were abundant in stem tissues. The total amino acids of the A. victorialis stem tissue from Teawha pass peak sample (837 mg/100 g dry wt) were higher than the mean of other population samples (355-824 mg/100 g dry wt). However, content of amino acids in the bulb was high in A. victorialis from Nari basin (1,919 mg/100 g dry wt).

• 한국유기농업학회지
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• 제15권3호
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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.

• 한국인구학
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• 제19권2호
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• pp.77-105
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• 1996

농촌사회의 당면한 문제는 농촌인구의 극소와 잔존인구의 성·연령별 인구구조의 왜곡에서부터 제기되므로 농촌인구의 변화추세를 검토하였다. 그리고 최근 군부로의 전입과 전출 인구를 비교하여 최근 농촌으로의 인구회귀현상의 실태를 분석하였다. 끝으로 농촌의 인구실태를 파악하기 위하여 실시한 농촌마을 조사자료를 분석하여 농촌으로 전입하는 인구의 영향을 밝혔고, 특성별 농촌마을의 장래를 예측하였다. 군부의 인구는 도시로의 인구전출이 지속되면서 젊은 연령층과 영유아의 인구구성비가 낮고 노인연령층이 두텁게 되었다. 산업화 이전단계인 1960년 군부의 0∼4세 인구구성비는 시부보다 높았으나 농촌인구의 도시전출이 누적되면서 1975년부터 시부보다 낮아졌다. 그러나 1995년의 군부 0∼4세 인구구성비가 6.2%로 5년전보다 상승하여 시부와 차가 감소되었다. 또한 1980년대 후반에 시부에서 군부로 이동하는 인구의 연령별 구성에서 20∼34세에 총이동인구의 51.8%가 집중되어 있었으며, 이들의 교육수준은 시부로의 전입인구보다 오히려 높았다. 이러한 사실은 농촌사회의 변화로 나타내게 될 것이다. 그러나 순수농촌마을이라고 할 수 있는 보은군의 농촌마을과 원래 농업중심 마을이었으나 최근에 급속히 변하고 있는 파주군의 근교농촌마을의 인구구조를 비교한 결과 최근의 농촌인구구조의 변화와 젊은 연령층의 군부로 전입하는 현상은 일부 농촌, 특히 근교농촌의 변화에 의한 현상이지 전체 농촌인구형상의 변화라고 할 수 없었다. 이들 마을 실태조사에서 밝혀진 마을 인구구조의 특성에서 우리는 산업화나 도시의 영향을 받지 않는 순수농촌마을은 거주민의 노령화가 극단적으로 진행되어 마을 자체의 존속이 어려워지는 반면에 근교 농촌마을은 농촌의 성격이 흐려지면서 도시화 내지 산업화가 진행되는 것을 알 수 있었다. 않는 임신, 성감염증, 그리고 인공유산 등의 위험으로부터 제대로 보호를 받아야 한다고 믿는다.보완하는 벤치마크 기능도 수행하기 때문이다.국의 대외 이미지 개선을 위한 적극적인 PR활동과 기업의 최고경영자 차원의 로비활동 추진으로 대미(對美)로비체제를 적극적이며 능동적으로 수행할 수 있도록 하여야 한다.였고, W.X 조국은 동쪽으로 265.2m, W.Y 조국은 북쪽으로 279.5m, 그리고 X.Y 조국은 북서쪽으로 224.3m 편위하여, Loran - C 위치가 GPS 위치보다 약 250m 더 편위 된 것을 알 수 있었다.경우 본 논문에서 계산한 각 침로교각에 대한 최소피항개시거리와 안전피항개시거리을 미리 염두해 두고 피항조선을 하게 되면, 감각에 의한 조선방법으로 야기되는 충돌해난사고를 지양 할 수 있으리라 사료된다.만도에 따른 유의적인 증가를 (p<0.05)보여주었으나 여자의 경우는 유의적인 차이가 없었다. TG의 수치는 남자의 경우 KI가 110%미만인 그룹은 $102.9\pm108.2mg/dl,$ 120% 이상인 그룹은 $112.2\pm40.0mg/dl로$ 비만도가 증가함에 따라 TG가 증가되었으나 유의적인 차이는 없었으며, 여자의 경우 유의적인 차이가 없었다. 남자의 경우 HDL-C은 비만도가 증가함에 따라 유의적으로 감소하는 경향을 보였으나(p<0.05) 여자의 경우는 유의적인 차이가 없었다. 6. 조사 대상자의 체지방량 측정결과 체기방률은 남자의 겨우 16.4% 여자의 겨우 24.0%로 나타나 여자의 체지방률이 남자보다 높았다. 7. 신체계측치, 혈압, 혈청 지질간의 상관관계를 살펴보면 TC, TG는 KI, BMI와 유의적인 양의 상관관계를 보였고 (p<0.01), HCL-C은 비체중, BMI, LBM, TBM와 유의적인 음의 상관관계를 보였으며,