• Journal of Korean Society on Water Environment
• /
• v.39 no.4
• /
• pp.316-328
• /
• 2023

In this study, the characteristics of nonpoint pollutant outflow and contribution rate of pollution in Songya-stream mainstream and tributaries were analyzed. Further, water pollution management and improvement measures for pollution-oriented rivers were proposed. An on-site investigation was conducted to determine the inflow of major pollutants into the basin, and it was found that pollutants generated from agricultural land and livestock facilities flowed into the river, resulting in a high concentration of turbid water. Based on the analysis results of the pollution load data calculated through actual measurement monitoring (flow and water quality) and the occurrence and emission load data calculated using the national pollution source survey data, the S3 and S6 were selected as the concerned pollution tributaries in the Songya-stream basin. Results of cluster analysis using Pearson correlation coefficient evaluation and Density based spatial clustering of applications with noise (DBSCAN) technique showed that the S3 and S6 were most consistent with the C2 cluster (a cluster of Songya-stream mainstream owned area) corresponding to the mainstream of Songya-stream. The analysis results of the major pollutants in the concerned pollution tributaries showed that livestock and land pollutants were the major pollutants. Consequently, optimal management techniques such as fertilizer management, water gate management in paddy, vegetated filter strip and livestock manure public treatment were proposed to reduce livestock and land pollutants.

• Korean Journal of Human Ecology
• /
• v.3 no.1
• /
• pp.33-42
• /
• 1994

The main objective of this study was to find urban housewives' expenditure behavior type. For this objective 4 dimensions of income expenditure behavior were classified with factor analysis and correlation coefficient and then cluster analysis was implemented. Subjects were housewives living in Seoul. As a result, three income expenditure behavior type were defined. They were type of high interested in income expenditure, time oriented type, and money oriented type.

• Korean Journal of Microbiology
• /
• v.27 no.4
• /
• pp.378-384
• /
• 1989

The numerical taxonomy of heterotrophic bacterial community in Lake Soyang was analysed. 95, 115, 88 and 75 strains which were isolated at each season from spring in 1987 to winter in 1988 were clustered by single matching coefficient. The diversity indices (H') were in the range of 0.511-1.684, and the community was most diverse in spring. THe seasonal variation of generic composition was significant. Of the domonant genera, Acinetobacter, Pseudomonas, and Flavobacterium were representative.

• The Korean Journal of Applied Statistics
• /
• v.18 no.2
• /
• pp.371-379
• /
• 2005

In this paper, we propose a pattern consistency index for detecting heterogeneous time series that deviate from the representative pattern of each cluster in clustering time course gene expression data using the Pearson correlation coefficient. We examine its usefulness by applying this index to serum time course gene expression data from microarrays.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.14 no.8
• /
• pp.3257-3269
• /
• 2020

Articulation disorders are characterized by an inability to achieve clear pronunciation due to misuse of the articulators. In this paper, a method of detecting such disorders by comparing to the standard pronunciations is proposed. This method defines the standard pronunciations from the speeches of normal children by clustering them with three features which are the Linear Predictive Cepstral Coefficient (LPCC), the Mel-Frequency Cepstral Coefficient (MFCC), and the Relative Spectral Analysis Perceptual Linear Prediction (RASTA-PLP). By calculating the distance between the centroid of the standard pronunciation and the inputted pronunciation, disordered speech whose features locates outside the cluster is detected. 89 children (58 of normal children and 31 of children with disorders) were recruited. 35 U-TAP test words were selected and each word's standard pronunciation is made from normal children and compared to each pronunciation of children with disorders. In the experiments, the pronunciations with disorders were successfully distinguished from the standard pronunciations.

• International Journal of Fluid Machinery and Systems
• /
• v.4 no.1
• /
• pp.150-160
• /
• 2011

This study focuses on the Achard turbine, a vertical axis, cross-flow, marine current turbine module. Similar modules can be superposed to form towers. A marine or river hydropower farm consists of a cluster of barges, each gathering several parallel rows of towers, running in stabilized current. Two-dimensional numerical modelling is performed in a horizontal cross-section of all towers, using FLUENT and COMSOL Multiphysics. Numerical models validation with experimental results is performed through the velocity distribution, depicted by Acoustic Doppler Velocimetry, in the wake of the middle turbine within a farm model. As long as the numerical flow in the wake fits the experiments, the numerical results for the power coefficient (turbine efficiency) are trustworthy. The overall farm efficiency, with respect to the spatial arrangement of the towers, was depicted by 2D modelling of the unsteady flow inside the farm, using COMSOL Multiphysics. Rows of overlapping parallel towers ensure the increase of global efficiency of the farm.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.17 no.2
• /
• pp.32-38
• /
• 2018

Studies on classification of national roads have been continued, but there is little research on the classification of urban arterial roads. Due to the increase of traffic volume, urban arterial roads do not perform well as main roads. In this paper, the function of urban arterial road was established by using cluster analysis using traffic characteristics. Traffic characteristics such as traffic volume, weekend coefficient and speed coefficient were used to establish the functions of 55 main arterial roads in Seoul. The results of this paper are compared with those of the method using AADT. The method using AADT classifies the characteristics according to the traffic volume of the whole lane. In this paper, however, the results are derived using the traffic volume per lane reflecting the actual traffic volume. In addition, the functional classification of the arterial roads in Seoul was compared with the results of this paper to verify that the traffic characteristics were reflected. As a result, the method presented in this paper is more effective in showing traffic characteristics than the current highway functional classification method, and the functional classification system will be helpful for road extension and planning design.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.2B
• /
• pp.237-248
• /
• 2008

Precipitation variability in Korea is mainly influenced by climate circulation such as sea surface temperature, not a local convection. Therefore, this study investigates relationship between monthly precipitation of 61 station observed by Korea Meteorological Administration and global sea surface temperatures (SSTs). The main components of monthly precipitation in Korea are extracted by a method which consists of the principal analysis combined with the cluster analysis, to examine the correlation between monthly rainfalls and SSTs. The relationships between main components of monthly precipitation and SSTs exists in Pacific Ocean. At the result of Wavelet Transform analysis, The 2-4 year band have a strong wavelet power spectrum and the low frequency. the correlation coefficient between low frequency components of monthly rainfalls and SSTs calculated bigger then correlation coefficient between main components and SSTs. Hence, these results propose a prediction possibility of monthly precipitations using the varition of SSTs.

• The Research Journal of the Costume Culture
• /
• v.8 no.6
• /
• pp.930-939
• /
• 2000

This study was done to provide the fundamental data for scientific and rational children's clothing sizing system by investigating their somatometric characteristics and classifying somatotypes. The subjects were 269 elementary schoolgirls aged from 7 to 8 years old living in Pusan and Kyungsangnam-do. Data from each girl comprises 28 anthropometic measurments and 4 photographic measurments, related to the lower half of body. To analyze somatotypes of the lower half of body, factor analysis, cluster analysis, discriminant analysis were performed for statistical analysis of the data. As to the analysis to draw somatometric factors by this age group, five factors which explain 76.85% of the whole variances were extracted. The first and second factors which explain more than 60% of the whole variances represent 'horizontal size'and 'vertical size', which characterize most aspects of the body shape of the subjects. On the basis of the cluster analysis, three different lower half of body types were categorized. Type Ⅰ has biggest horizontal size, average vertical size and most protruded belly. Type Ⅱ has average degree of horizontal size, quite big vertical size and most protruded hips. Type Ⅲ has smallest horizontal and vertical size. According to the analysis to discriminate somatotypes of the lower half of body of this age group, weight and waist circumference of discriminant function 1 and abdominal circumference of discriminant function 2 have coefficient values.

• Horticultural Science & Technology
• /
• v.31 no.3
• /
• pp.322-327
• /
• 2013

The genetic diversity and phylogenetic relationships of eleven herbaceous peonies grown in Korea were analyzed by random amplified polymorphic DNA (RAPD). Twenty-four decamer RAPD primers were used in a comparative analysis of these Korean peony species. Of the 142 total RAPD fragments amplified, 124 (87.3%) were found to be polymorphic. The remaining 18 fragments were found to be monomorphic (12.7%) shared by individuals of all 11 peony species. Cluster analysis based on the presence or absence of bands was performed by Jaccard's similarity coefficient, based on Unweighted Pair Group Method with Arithmetic Averages. Genetic similarity range was 0.39 to 0.90 with a mean of 0.64. This study offered a rapid and reliable method for the estimation of variability among different peony species which could be utilized by the breeders for further improvement of the local peony species. Also, the results propose that the RAPD marker technique is a useful tool for evaluation of genetic diversity and relationship amongst different peony species.