• Nuclear Engineering and Technology
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• v.56 no.7
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• pp.2452-2457
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• 2024

To obtain site-specific values of the Derived Concentration Guideline Levels (DCGLs) for decommissioning of KRR-1&2, the soil density and distribution coefficient values for Cs-137, a major contaminant radionuclide, were determined. The soil density was evaluated according to the test method established by the Korean Agency for Technology and Standards of the Ministry of Trade, Industry, and Energy (KATS). The distribution coefficient was evaluated using a batch test. The validity of using the evaluated soil density and distribution coefficient as site-specific values was assessed through radiation dose assessment reflecting these values. Average soil density value obtained was 1.738 g/cm³, which was within the typical range of normal soil density, 1.0-1.8 g/cm³. The average distribution coefficient value was 7,754 mL/g. Applying the maximum, average, and minimum values of the evaluated soil density and distribution coefficient showed similar radiation dose results, thus suggesting that it is reasonable to use the average values of each parameter as site-specific values. Findings of this study can help determine DCGLs that reflect the characteristics of the research reactor site.

• Journal of the Economic Geographical Society of Korea
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• v.10 no.3
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• pp.319-331
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• 2007

Nowadays, urbanized area expands its boundary, and distribution of urbanized area is gradually transformed into more complicated pattern. In Korea, SMA(Seoul Metropolitan Area) has outstanding urbanized area since 1960. But it is ambiguous whether urban distribution is clustered or dispersed. That is to say, it is difficult to understand spatial distribution pattern of urbanized area, although urbanized area has grown gradually. This study aims to show the way in which expansions of urbanized area impact on spatial distribution pattern of urbanized area. We use GIS analysis based on raster dataset, quadrat analysis, and nearest neighbor analysis to know distribution pattern of urbanized area in time-series urban growth. Experiments show that cohesion of SMA's urbanized area had increased to the early 1980s, but has decreased from the middle 1980s. Also, urban growth of SMA has been characterized not by spillover growth but by leapfrogging growth and road-influenced growth since the middle 1980s.

• Journal of the Korean Magnetics Society
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• v.12 no.1
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• pp.20-23
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• 2002

The local coercivity distribution of CoCrPt alloy films prepared by dc magnetron sputtering has been investigated by means of a magneto-optical microscope magnetometer (MOMM) capable of simultaneously measuring the local properties on 400 nm spatial resolutions. Serial samples of CoCrPt alloy films were prepared with the Pt composition of a range from 6 to 28 at. %. We find that the local coercivity distribution crosses over from Gaussian to non-Gaussian distribution in CoCrPt alloy films with increasing Pt composition, with increasing trends in the width of the distribution as well as the average local coercivity. Transmission electron microscopy (TEM) studies reveal that our findings are closely correlated with the dependences of the grain size distribution and its average size on Pt concentration.

• Journal of Ecology and Environment
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• v.38 no.4
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• pp.493-503
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• 2015

This study analyzed how spatial distribution of Himantormia lugubris is affected by the microenvironment in the Antarctic Specially Protected Area (ASPA) No. 171 located in the Barton Peninsula of King George Island that belongs to the maritime Antarctic. In order to determine the population structure of H. lugubris growing in Baekje Hill within ASPA No. 171, we counted the individuals of different size groups after dividing the population into 5 growth stages according to mean diameter as follows: ≤ 1 cm, 1-3 cm, 3-5 cm, 5-10 cm, and ≥ 10 cm. The count of H. lugubris individuals in each growth stage was converted into its percentage with respect to the entire population, which yielded the finding that stages 1 through 5 accounted for 32.8%, 25.3%, 15.9%, 22.5%, and 3.5%, respectively. This suggests that the population of H. lugubris in ASPA No. 171 has a stable reverse J-shaped population structure, with the younger individuals outnumbering mature ones. The mean density of H. lugubris was 17.6/0.25 m², mean canopy cover 13.3%, and the mean dry weight 37.8 g/0.25 m². It began to produce spore in the sizes over 3 cm, and most individuals measuring 5-10 cm were adults with sexually mature apothecia. The spatial distribution of H. lugubris was highly heterogeneous. The major factors influencing its distribution and performance were found to be the period covered by snow, wind direction, moisture, size of the substrate, and canopy cover of Usnea spp. Based on these factors, we constructed a prediction model for estimating the spatial distribution of H. lugubris. Conclusively, the major factors for the spatial distribution of H. lugubris were snow, wind, substrate and the competition with Usnea spp. These results are important for understanding of the distribution in the maritime Antarctic and evolution of H. lugubris that claims a unique life history and ecological niche.

• Journal of Digital Convergence
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• v.14 no.5
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• pp.95-106
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• 2016

The major thrust of this research focuses on the development of phased big data distribution model based on the big data ecosystem. This model consists of 3 phases. In phase 1, data intermediaries are participated in this model and transaction functions are provided. This system consists of general control systems, registrations, and transaction management systems. In phase 2, trading support systems with data storage, analysis, supply, and customer relation management functions are designed. In phase 3, transaction support systems and linked big data distribution portal systems are developed. Recently, emerging new data distribution models and systems are evolving and substituting for past data management system using new technology and the processes in data science. The proposed model may be referred as criteria for industrial standard establishment for big data distribution and transaction models in the future.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.6 no.1
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• pp.57-64
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• 2003

This study aims to discuss the characteristics on marketing distribution of landscape materials after consideration in the side of cognition on the present condition of marketing which is important factors for analysis in understanding the market of landscape materials. To do this, the investigation of marketing distribution are to collect data refer to purchases and sales reports and questionnaires, these results are used to analyzed the operative factor of forming market structure and problematic, improvement spot of marketing distribution. The periodic range of this paper is limited on 609 landscape materials and examination was performed from 21.Feb. to 15.Mar, in 2002. The results of the whole prices trends and marketing distribution survey can be summarized as follows : 1. Differences of cognition on marketing distribution among four group toward problematic spot on product and marketing of landscape materials was summarized as follows : 1) Group of landscape design : Interest of government, Various articles. 2) Group of landscape construction : Communication of marketing information, Role of intermediary ecc. 3) Group of landscape materials and cooperation between company and university : Interest of government ecc, 2. Differences of cognition on marketing distribution among four group toward improvemental spot on product and marketing of landscape materials was summarized as follows : 1) Group of landscape design and construction : Network of marketing distribution on landscape materials, Criterion of articles, Quality adiministration through establishment of sale level ecc.. 2) Group of landscape materials : Employment of specialist education program ecc.. 3) Group of cooperation between company and university : Conscious reformation of comsumer ecc.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.2A
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• pp.121-127
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• 2011

Spatial distribution of void space in concrete materials strongly affects mechanical and physical behaviors. Therefore, the identification of characteristic void distribution helps understand material properties and is essential to estimate the integrity of material performance. The 3D micro CT (X-ray microtomography) is implemented to examine and to quantify the void distribution of a lightweight aggregate concrete using an image analysis technique and probabilistic approach in this study. The binarization and subsequent stacking of 2D cross-sectional images virtually create 3D images of targeting void space. Then, probability distribution functions such as two-point correlation and lineal-path functions are applied for void characterization. The lightweight aggregates embedded within the concrete are individually analyzed to construct the intra-void space. Results shows that the low-order probability functions and the density distribution based on the 3D micro CT images are applicable and useful methodology to characterize spatial distribution of void space and constituents in concrete.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.5
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• pp.1143-1148
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• 2014

This paper has analyzed the change of subthreshold swing for doping distribution function of asymmetric double gate(DG) MOSFET. The basic factors to determine the characteristics of DGMOSFET are dimensions of channel, i.e. channel length and channel thickness, and doping distribution function. The doping distributions are determined by ion implantation used for channel doping, and follow Gaussian distribution function. Gaussian function has been used as carrier distribution in solving the Poisson's equation. Since the Gaussian function is exactly not symmetric for top and bottome gates, the subthreshold swings are greatly changed for channel length and thickness, and the voltages of top and bottom gates for asymmetric double gate MOSFET. The deviation of subthreshold swings has been investigated for parameters of Gaussian distribution function such as projected range and standard projected deviation in this paper. As a result, we know the subthreshold swing is greatly changed for doping profiles and bias voltage.

• Journal of Ecology and Environment
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• v.33 no.1
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• pp.67-77
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• 2010

Stand structure and spatial associations of the dominant tree species in Quercus mongolica stands were investigated to understand interspecific relationships and the persistent dominance of Q. mongolica. We examined the species composition, DBH (diameter at breast height) distribution, and spatial distribution of trees (${\geq}\;2.5\;cm$ DBH) in two permanent $100\;m\;{\times}\;100\;m$ plots in Q. mongolica-dominant stands on the western part of Mt. Jiri. Ripley's K-function was used to characterize the spatial patterns and associations of dominant tree species. Q. mongolica showed a continuous and reverse-J shaped DBH distribution with clumped spatial distribution in both study sites. Q. mongolica and Abies koreana exhibited a negative association implying potential interspecific competition. The positive spatial association between Q. mongolica and Alnus hirsuta var. sibirica and Fraxinus sieboldiana were affected by site characteristics: limited habitat conditions with a large proportion of rock surface. Our results suggest that interactions among species were complex and ranged from positive to negative. Differences in stand and site characteristics and regeneration mechanisms among the species play an important role in regulating their spatial distribution patterns, while competition between individuals also contributes to spatial patterning of these communities. The high density and the early developmental stage of spatial distribution and structural characteristics of Q. mongolica and the relatively low importance values of other species in the stands imply that Q. mongolica will remain dominant in the study sites in the near future.

• The Journal of Pediatrics of Korean Medicine
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• v.18 no.1
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• pp.1-9
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• 2004

Objectives: The purpose of this study was clinical review of pediatric patients with fracture that visited oriental medicine center. Methods: In retrospective study, the pediatric patients, who were visited to oriental medicine center due to fracture, were classified by sex, age, fracture site, date of accident, injury mechanism, time of treatment, kind of treatment. Results and Conclusion: Total 32 patients were visited due to fracture from April 2001 to March 2004. Male Patients were 27, female were 5. In distribution of age, 10 year-old and 11 year-old were 40.7% of totality. In distribution of month, May was 10(31.3%), June was 6(18.8%), and March was 4(12.5%). There are more patients with fracture in spring than other season. In distribution of fracture site, foot was 15(46.9%), hand was 7(21.9%), ankle was 4(12.5%), upper extremity was 3(9.4%), clavicle was 2(6.3%), tibia was 1(3.1%). In distribution of injury mechanism, slip down was 23(71.9%), impaction 5(15.6%), fall down 3(19.4%), crushing injury 1(13.1%). In distribution of injury motive, soccer was 8(25.0%), basketball 4(12.5%), skating 3(9.4%), cycling 2(6.3%), sliding 1(3.1%), Tae-kwon-do 1(3.1%), other sports 5(15.6%), collision 1(3.1%), walking 2(6.3%), hit 3(9.4%), etc. 2(6.3%). In distribution of treatment account, one time was 23(71.9%), twice 3(9.4%), three times 2(6.3%), four times 2(6.3%), five times 2(6.3%). In distribution of treatment time, 1 week was 26(81.3%), 2 weeks 4(12.5%), 3 weeks 2(6.3%). In distribution of treatment kind, acupuncture treatment was 18(56.3%), negative cupping 7(21.9%), splint 13(40.6%), and other treatment(coban taping, medical patch, and so on) 5(15.6%), transfer 14(43.8%).