• Korean Journal of Hydrosciences
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• v.8
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• pp.85-95
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• 1997

The multiple flow direction algorithm to calculate the spatial variation of the saturation tendency, I. e. topographic index, is integrated into the Geographic Information System, GRASS. A procedure is suggested to consider the effect of a tile system on calculating the topographic index. A small agricultural subwatershed ($3.4\;\textrm{km}^2$) is used for this study. The impact of a tile system on the groundwater table can be effectively considered by the Laplace's equation to the DEM. The analysis shows that a tile system has a high degree of saturation to compared to the case without tile drainage, and the predicted riparian area is well fitted to the actual watershed condition. A procedure is suggested to consider a tile system's effect on calculating the topographic index.

• The Korean Journal of Zoology
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• v.35 no.4
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• pp.497-504
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• 1992

한국특산종인 Colitis rotundicuudutu의 지리적 변이를 전국 5개 집단 132개체를 대상으로 조사하였다. 4개 집단의 계측형질로 본 다변량분석 결괴 산청집단은 타 집단과 형태적 차이가 있었다 전기영동으로 조사된 5개 집단의 평균 유전적 변이 정도는 A=1.48, P=37. IpA, HD=0. 139, 및 H6=0. 124로 변이 정도가 타 어류에 비하여 비교적 높았다. 5개 집단의 평균 유전적 근인치(S)는 0.83으로 낮았으나 산청집단을 제외한 4개 집단의 근연치는 0. 91로 매우 가까웠다. 반면 산청집단은 나머지 집단과 형태적으로나 유전적으로 유의한 차이가 나타나는 것으로 보아 산청집단의 별종 가능성이 매우 높음을 시사한다. 앞으로 보다 면밀한 연구로 산청집단의 별종 여부를 명백히 구명하여야 할 것이다.

• The Korean Journal of Zoology
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• v.34 no.4
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• pp.585-593
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• 1991

한국 특산종 C. longicolpus의 지리적 변이를 조사하고자 discriminant function 분석에 의한 형태적 변이 그리고 전기영동법에 의한 유전적 변이를 전국적으로 조사하였다. 11개 집단의 discriminant function분석결과 11개 집단은 형태적으로 뚜렷한 차이 없이 유사하였다. 13개 집단의 유전적 변이를 조사한 결과는 13개 집단 평균 A = 1.37, P = 29.96%, HD = 0.076 및 HG = 0.083으로 일반적인 담수어류의 종내 집단 간 평균 유전적 변이정도보다 다소 높게 나타났다. 평균 유전적 근연치는 5 : 0.88으로 타 어종의 일반적인 집단 및 유전적 근연정도와 유사하였다.

• Plant Resources
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• v.8 no.3
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• pp.293-299
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• 2005

This study used RAPD markers to assume genetic diversity and variation in selected populations of Hovenia dulcis var. koreana. Ratio of polymorphic RAPD markers were 93.4% in selected populations of Hovenia dulcis Thunb., difference of genetic structure among populations and within populations showed 16.45%, 83.55%, respectively in amount of total genetic variation of 4 populations. Total gene diversity($H_T$) that show genetic diversity appeared 0.313 and coefficient of gene differentiation($G_{ST}$) that compare genetic differentiation of populations appeared 0.1645, analysis of AMOVA for variation among populations and within populations was significantly different (P<0.001). Genetic diversity of whole populations showed that 12.44% difference among population and 87.56% difference within populations. As a result, difference within populations was larger than difference among populations in genetic diversity. Nei's genetic distance and cluster analysis appeared that mean genetic distance among populations was 0.076, thus dividing two main groups and geographic relationship did not show in populations.

• Journal of the Korean Association of Geographic Information Studies
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• v.17 no.4
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• pp.112-128
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• 2014

This study aims to analyse the variation of spatial accessibility pattern based on 2SFCA(2 Step Floating Catchment Area) by changing its parameter values. The general pattern of the result of 2SFCA analysis shows that the spatial accessibility value is decreased by growing base population, while the spatial accessibility value is increased by growing PPR(Provider to Population Ratio). The three characteristics of local pattern in the Gumi City are founded by cluster analysis on the sensitive analysis procedure. Firstly, the variation of the accessibility values is insignificant in the fringe area of the Gumi City. Secondly, the variation of the accessibility values is diverse in the surrounding area of the welfare facilities. Especially, Dong areas are more sensitive to PPR variation, while others are more sensitive to base population variation. Thirdly, the larger parameter values, the more the spatial accessibility of the central areas, where elder people can access welfare facilities more easily, is improved. It needs to choose parameter values with caution to analyse spatial accessibility based on 2SFCA.

• Journal of the Korean Association of Geographic Information Studies
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• v.6 no.1
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• pp.24-36
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• 2003

Many rainfall-runoff model, which is applied discharge calculation for effective water-resource planning and management needs topographic and parameter of basin character. But it is very difficult to apply real a phase. Accordingly in this study filling up these problems. Applying GIS(geographic information system) through environment creating input data or concerning with GIS and rainfall runoff model. We built environment that analyze hydrograph showing discharge variation by time. GIS software for constructing input data is used by ArcView. For analysis of hydrograph in Basin, TOPMODEL applied topographic index. Besides for estimate of appliance to rainfall-runoff model, simple storm event and complex storm event are applied rainfall data which was before.

• Korean Journal of Plant Resources
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• v.20 no.4
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• pp.336-341
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• 2007

This study was carried out to investigate geographic variation in needle characteristics of Pinus densiflora, one of the most economically important tree species in Korea. Needles were collected from 35 natural populations and their morphological and anatomical characteristics were studied. ANOVA showed statistically significant differences among populations as well as among individuals within populations in needle length, needle width, number of stomata row, density of stomata in $0.25mm^{2}$, number of serrations in 0.5mm, and number of resin ducts. In all these traits, variance components among individuals within populations were larger than those among populations. The density of stomata in $0.25mm^{2}$ increased as the latitudes and elevations of the populations increased, while the number of serrations in 0.5mm decreased as the decrease of latitudes and elevations. The number of resin ducts was higher in inland populations than in coastal populations. The resin duct index appeared to be higher in western populations than in eastern populations. Cluster analysis based on morphological characteristics divided populations into three groups. The third group was composed of populations selected from the Taebaek mountains. The number of serrations in 0.5mm of this group was lower than that of other two groups, while the density of stomata in $0.25mm^{2}$ was higher.

• The Korean Journal of Zoology
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• v.8 no.1
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• pp.8-10
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• 1965

1. We have observed the frequency , geographi variation and microgeographic variation of the elytral pattern types and the elytral edge of the population of Lady-beetle, Harmonia axyridis PALLACE, collected in Jinju and other 6 localitites in South Korea. 2. the number of specimen collected were 6,625 in which Succinea was 90.32% : Axyridis ; 0.74% : Spectabilis , 3.82% ; and Conspicua 5.07%. 3. We have found that 92.26% of all specimens have elytral edge. 4. There were some differences in the compositional of the elytral pattern types and elytral edge to the population among the Western seaside , inland and southern seaside of South Korea , whereas as great difference was in the compositional proportion tot he population of Spectabilis between the western and southern seaside . There was also a gret difference of the elytral edge between the inland and southern seaside. 5. A micro-geographic variation was observed in Jinju , located on southern area of South Korea. In the samples collected from the pine trees at Jinju area the Succinea occupied 73.25%, and 69.61 % were found to be provided with elytral edge, while in the general population 92.46% of specimen were Succinea and 98.35% were found to have elytral edge.

• Journal of Biosystems Engineering
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• v.25 no.3
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• pp.241-250
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• 2000

The feasibility of precision fertilizing for small size fields was studied by determining fertilizing amount of nitrogenous and calcareous to a cite specific region. A detailed soil survey at three experimental fields of $672m^2$, $300m^2$ and $140m^2$ revealed a considerable spatial variation of the pH and organic matter(OM) levels. Soil organic matter was measured using Walkley-Black method and soil pH was measured with a pH sensor. Soil sample was obtained by Grid Node Sampling Method. The soil sampling depth was 10∼20 cm from the soil surface. To display soil nutrient variation, a soil map was made using Geographic Information System (GIS) software. In soil mapping, soil data between nodes was interpolated using Inverse Distance Weighting (IDW) method. The variation was about 1∼1.8 in pH value and 1.4∼7% in OM content. Fertilizing Amount of nitrogenous and calcareous was determined by th fertilizing equation which was proposed by National Institute of Agricultural Science and Technology(NIAST). The variation of fertilizing amount was about 3∼11 kg/10a in nitrogenous and 70∼140 kg/10a in calcareous. The results showed a feasibility of precision fertilizing for small size fields.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.4
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• pp.1711-1712
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• 2012

Variation in diet and the rates of colorectal cancers have confounded researchers in recent years. Comparisons of populations in different geographic locations and of different ethnic origins have shown considerable differences in disease frequency, location and relation to diet. This paper revisits an earlier comparison of Maori rates of disease and diet based on data from 20 years ago with surprising changes in disease rates today.