• Asian Journal of Turfgrass Science
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• v.10 no.3
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• pp.247-262
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• 1996

In this study, the distribution of dictyostelid cellular slime molds was investigated from F, H and $A_1$ horizon of pinus, oak forests in Mt. Puk'an, Mt. Nam and Mt. Kwanak. The relationship of cellular slime molds with other soil microorganisms and abiotic factors were analyzed. The six species were isolated as follows: Polysphondlium pallidurn, Dictyostelium purpureum, D. mucoroides, D. crassicaule, D. capitatum, D. implicatum. The dominant species in pinus forests was P. pallidum, and in oak forests it was D. macro ides. In Mt. Nam, D. mucoroides and P. pallidum were isolated at only oak forest. The Correlations of slime mold abundance with bacteria were significant. Even though positive correlations of cellular slime molds with actinomycetes or fungi were not significant, correlations between soil microorganisms were analyzed. Correlation coefficients were high in Mt. Kwanak(r=0.5921) and Mt. Nam(r=0.7243) at significant level P<0.01. There were significant correlations between total slime molds and abiotic factors. It supports that cellular slime molds are limited by foods in nature. In low level of pH, water content and organic matter, that community diversity is more affected by bacteria whose organic degradation capacity is regulated by interactions of soil microorgaisms. Key words: Cellular slime molds, Soil microorganisms, Correlations, Abiotic factors.

• Journal of Plant Biology
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• v.15 no.1
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• pp.1-12
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• 1972

As part of the study of the structure and the successional trends of our temperate forests, a quantitative survey was made of the relatively well conserved forest stands on Mt. Kwanak, Seoul. Three community types were observed; the Pinus densiflora-Quercus mongolica community, the Pinus densiflora community, and the Quercus mongolica community. Evidence suggests that the dominance of Pinus densiflora and quercus mongolica will continue in the Pinus densiflora-Quercus mongolica community, however, in the Pinus densiflora community the dominant species, Pinus densiflora, is now being replaced by Quercus mongolica. The trend toward an increased in Acer pseudo-sieboldianum var. koreanum, Fraxinus rhynchophylla, Carpinus cordita, and Acer mono is observed in the Quercus mongolica community. An analysis of the overall composition of the forest reveals that the upper story is mostly occupied by Quercus mongolica and Pinus densiflora, the shrub layer by Rhododendron schlippenbachii and Lespedeza maximowiczii, and the herb layer by Spodiopogon cotulifer and Artemisia keiskeana. Quercus mongolica may cover most part of the forest, gradually excluding Pinus densiflora. Acer pseudo-sieboldianum var. koreanum, Fraxinus rhynchophylla, Carpinus coradata, and Acer mono are increasing in importance with the potentiality of developing into major canopy components. With the diversification of the physical habitat Cephalotaxus koreana and Magnolia sieboldii, the species which had almost completely been eliminated form the forest through the severe interferences, have reappeared.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.522-522
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• 2015

In this study, the effect of threshold applied to the radar rain rate on the comparison of the radar and rain gauge rain rate was theoretically examined. The result derived was also evaluated theoretically, using the Bernoulli random field, and empirically, using Mt. Kwanak weather radar data. The results are summarized as follows. (1) In the application to the Bernoulli random field, it was found that the comparison of the radar and rain gauge rain rate with threshold does not introduce any systematic bias. (2) The same results could also be derived in the application to Mt Kwanak weather radar data. In all cases with several radar bin sizes and thresholds considered, the bias was estimated to be far less than 10% of the mean of the rain gauge rain rate. (3) However, in the comparison with threshold applied to both the radar and rain gauge rain rate, the bias was estimated to be higher than 20%. That is, the systematic bias was introduced. This result indicates that the comparison with threshold applied to both the radar and rain gauge rain rate should not be used.

• Journal of Korea Water Resources Association
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• v.38 no.12 s.161
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• pp.1039-1049
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• 2005

The objective of this study is to produce optimal radar-derived rainfall for hydrologic utilization. The ground clutter and beam blockage effects from Mt. Kwanak station (E.L 608m) are removed from radar reflectivities by POD analysis. The reflectivities are used to produce radar rainfall data in the form of rain rates (mm/h) by the application of the Marshall-Palmer reflectivity versus rainfall relationship. However, these radar-derived rainfall are underestimated in temporal and spatial scale compared with observed one, so it is necessary to hire a correction scheme based on the gauge-to-radar (G/R) statistical adjustment technique. The selected watershed for studying the real-time correction of radar-rainfall estimation is the Soyang dam site, which is located approximately 100km east of Kwanak radar station. The results indicate that adjusted radar rainfall with the gauge measurement have reasonal G/R ratio ranged on 0.95-1.32 and less uncertainty with that mean standard deviation of G/R ratio are decreased by $9-28\%$. Mean areal precipitation from adjusted radar rainfall are well agreed to the observed one on the Soyang River watershed. It is concluded that the real-time bias adjustment scheme is useful to estimate accurate basin-based radar rainfall for hydrologic application.

• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.291-294
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• 1995

In this paper, two algorithms for computing multiple or clustered eigenvalues are proposed. The algorithm can be applied to all kinds of Hermitian matrix unlike the existing algorithm. Characteristics of the proposed algorithms is examined by MATLAB simulations.

• Journal of the Korean Statistical Society
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• v.19 no.1
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• pp.88-92
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• 1990

In the problem of the recovery of interblock information in balanced incomplete block designs(BIBD), it is well known that a truncated estimator dominates the untruncated estimator under mean squared error loss. This paper shows that the domination result holds universally for every nondecreasing loss function.

• The Journal of Engineering Geology
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• v.10 no.2
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• pp.189-214
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• 2000

Three study areas of Kwanak campus(Seoul National University), Gapyung and Boeun were selected and classified according to bedrock types in order to investigate soil-gas radon concentrations. Several soil-gas samples showed relatively high radon concentrations in the residual soils which derived from granite bedrock. It also showed that water content of soil and the degree of radioactivity disequilibrium was a secondary factor governing radon emanation and distribution of radon radioactivity. The results of radon concentrations and working levels for forty rooms in Kwanak campus, Seoul National University, showed that indoor basement rooms under poor ventilation condition can be classified as high radon risk zone having more than EPA guideline(4 pCi/L). Some results of section analysis which was surveyed in the fault zone of Kyungju and Gapyung area confirmed the existence of fault-associated radon anomalies with a meaning of radon risk zone.

• Korean Journal of Community Nutrition
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• v.18 no.2
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• pp.112-124
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• 2013

This study was conducted to investigate how child-care teachers participate, practice mealtime instruction, and perceive difficulties in food service, focusing on comparison between the teachers caring two different age groups: children younger than three years (Younger Group) and those three years or older (Older Group). Questionnaires were distributed to 151 child-care centers in Kwanak-gu, Seoul, Korea during December, 2011. Only the data from 25 child-care centers, where two respective teachers in charge of Younger Group and Older Group completed the questionnaires, were analyzed. The results showed that there was no difference in terms of child-care teachers' participation in food service practice between the two groups, except for serving method; 'Pre-plated' serving was used significantly more often in Younger Group, whereas 'Line-up' serving was used in Older Group. Approximately, three quarters of the child-care centers had policies or guidelines on mealtime instruction. During mealtime, child-care teachers tended to use frequently verbal instructions such as "sit up straight when you eat" about eating manner, "don't be picky with your food" about eating habit, and "wash your hands before eating" about eating procedure in both the groups. There was no statistically significant difference regarding child-care teachers' perceived difficulties in food service between the two groups. These results indicated that child-care teachers' participation and mealtime instruction in food service did not differ between the two age groups, although children's development of digestion and eating skill differed by age. Therefore, training should be provided to child-care teachers about food service practices and mealtime instruction appropriate to children's age.

• Journal of the Korean Institute of Landscape Architecture
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• v.13 no.1
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• pp.43-66
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• 1985

Korea needs proper and rational public policies on conservation and use of forest land and other natural resources because of the accelerating expansion of national land developments in recent years. Unfortunately, there is no systematic planning system to support the needs. Generally, forest land use planning needs suitability analysis based on efficient land classification system. The goal of this study was to classify a forest land using multivariate satistical methods. A case study was carried out in winter of 1983 on a mountainous area higher than 100m above sea level located at Mt. Kwanak in Anyang -city, Kyung-gi-do (province). The study area was 19.80 km$^2$wide and was divided into 1, 383 Operational Taxonomic Units (OTU's) by a 120m$\times$120m grid. Fourteen descriptors were identified and quantified for each OTU from existing national land data : elevation, slope, aspect, terrain form, geologic material, surface soil permeability, topsoil type, depth of the solum, soil acidity, forest cover type, stand size class, stand age class, stand density class, and simple forest soil capability class. For this study, a FORTRAN IV program was written for input and output map data, and the computer statistics packages, SPSS and BMD, were used to perform the multivariate statistical analysis. Fourteen variables were analyzed to investigate the characteristics of their fire quench distribution and to estimate the correlation coefficients among them. Principal component analysis was executed to find the dimensions of forest land characteristics, and factor scores were used for proper samples of OTU throughout the study area. In order to develop the classes of forest land classification based on 102 surrogates, cluster and discriminant analyses of principal descriptor variable matrix were undertaken. Results obtained through a series of multivariate statistical analyses were as follows ; 1) Principal component analysis was proved to be a useful tool for data selection and identification of principal descriptor variables which represented the characteristics of forest land and facilitated the selection of samples.

• The Korean Journal of Ecology
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• v.8 no.2
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• pp.61-68
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• 1985

The modeling of interception and absorption of light was studied in plant canopies at Mt. Kwanak. Followering results were obtained. Light intensity passing through the stacked leaves is attenuated exponentially. This phenomenon seems to be more clearly applied to the plant canopies, if they have large cumulative leaf area and are matured densely. Light interception and absorption are influenced by leaf thickness, shape pigments, and leaf area, and they have great effect on the maturation of canopies. It was confirmed that the light penetrating through the stratified canopies is decreased exponentially in dual pattern. The cumulative leaf area of a definite space in a certain plant canopy is the same as the growth of leaf area of the canopy at that time. A hypothetical model for calculating the light absorption in plant canopies, was established on the bases of phenomena that incident light is captured at the maximum level and light inerception effect is minimized by leaves.