• Journal of Society of Preventive Korean Medicine
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• v.17 no.1
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• pp.181-197
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• 2013

Objectives : This study aimed to assess the differences in treatment behavior by reviewing data of a medical institution that studies treatment behavior in URI and assessing the treatment efficacy in Korea. Methods : We analyzed the behavior of medical customers and providers of upper respiratory infection medications using the NPS published by the Health Insurance Review Assessment Service. We created an operational definition for complications, and confirmed the difference in complication distribution between medical specialties. We also performed a multivariate analysis using a mixed model to elucidate the factors influencing the occurrence of complications. Results : The outcomes of analyzing factors to influence the difference in practice patterns of the diagnosing URI between the physicians are as follows; (1) Analysis of antibiotics prescriptions rate showed significant difference from medical departments (pediatrics; 49.7%, internal medicine; 54.2%, otorhinolaryngology; 69.6%, family medicine; 61.6%, general surgery; 57.5%, p<0.001). Analysis of steroid prescriptions rate showed significant difference from medical departments (pediatrics; 3.8%, internal medicine; 4.5%, otorhinolaryngology; 5.4%, family medicine; 3.0%, general surgery; 11.2%, p<0.001). (2) In patients who visited medical institutes with the common cold, the complication distribution differed according to the medical specialty, which suggests that specific complications arise depending on the particular medical specialty (p<0.001). (3) Moreover, through multivariate analysis, we found that the complication rate is higher in clinics than in hospitals, depending on the institute's size. (p<0.001; odds ratio of 4.67 in clinics than in hospitals, 95% CI 2.66-8.21) Conclusions : We observe a deviation between the behavior of patients diagnosed with URI and medication providers. This may arise from the interaction between providers and consumers, wherein the complications are associated with the choice of outpatient department and the prevention of cutting incentives. These findings suggest that the health policies should be improved to prevent inappropriate medical practice in the treatment of pediatric URI.

• Korean Journal of Plant Resources
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• v.22 no.1
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• pp.31-36
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• 2009

The aim of this study was to examine geographic variation to support a genetic resource conservation plan of rare endemic Picea jezoensis (Siebold & Zucc.) Carriere. Three populations of P. jezoensis were analysed using multivariate analysis for 7 characteristics of needle morphology. In the morphological characters, seven characters of needle were 15.11 mm (needle length), 1.43 mm (needle width), 0.42 mm (needle thickness), 10.9 (length / width of needle), 3.6 (width / thickness of needle), 0.47 mm (Distance between resin duct and vascular), 17.4 ea. (number of stomata row), respectively. Nested analysis showed that were statistically significant differences among populations as well as among individuals within populations in 6 quantitative characters. In 5 of 7 characters, variance components among populations were higher than those among individuals within populations. Cluster analysis using complete linkage method showed two groups (Mt. Gyebang populations was genetically distinct from the other two populations) to Euclidean distance 0.4. Among principal components, primary 2 principal components appeared to be major variables because of the loading contribution of 100%.

• The Korean Journal of Applied Statistics
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• v.18 no.1
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• pp.129-135
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• 2005

Representative observations are useful to express explicitly the distributional variation of the data by a few selected observations corresponding to the quantiles in the univariate situation. Jones and Rice(1992) extended it to the multidimensional case by the principal component based method. This study introduces a modified version of Jones and Rice exploiting the self-consistency of principal components in expressing the chosen observation vectors. Compared to that of Jones and Rice, the suggested method tends to provide with less susceptible representative observations to the sampling variation of the data and the resulted vectors benefits from the self-consistency.

• 한국해양학회지
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• v.20 no.2
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• pp.49-60
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• 1985

The interrelationships between distribution of phytoplankton and hydrographical conditions were studied from December 1983 to July 1984 in Yeongil Bay. The temporal variation of phytoplankton abundance seems to be mainly influenced by the vertical stability of water column and the freshwater run-off accompanied with possible nutrient input. The temporal progression of dominant species shows general succession pattern, especially skeletonema costatum was found a dominant species in each month. Although the differences between concentration of chlorophyll a and abundance of phytoplankton may be caused by cell size variation, during the study period they show felatively good linear manner. The phytohydrographic region based on multivariate analysis reflects the relationships between hydrographical condition and distribution pattern of phytoplankton.

• Korean Journal of Plant Resources
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• v.15 no.1
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• pp.36-42
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• 2002

Sixteen Atractylodes japonica Koidz. accessions were collected in Jeonbuk, Kyeongnam, Kangwon and Kyeonggi province, and their quantitative characteristics were compared with each other. The relationship of variation between Atractylodes japonica Koidz. accessions was also investigated by means of multivariate analysis. Hamyang 1 accession had the most desirable quantitative characteristics among the accessions: plant height was 86.2cm, number of leaves, 117.2 and number of stems, 34.3. Sudo 1 accession had 12 stems, the most among the accessions. The length of leaf margin serras found in all of them was on average 1.6mm. Most accessions had simple or palmately compound leaf with oval or elliptical type of the leaf shape. The accessions could be classified into three groups by average linkage cluster method. The most remote relationship was found between Group 1 containing Jinan 1, Jinan 2 and Group 3 containing Jeongsu, and Geoje.

• Membrane and Water Treatment
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• v.13 no.5
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• pp.245-257
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• 2022

Water quality characteristics and their spatial variations in the Nakdong River were statistically analyzed by multivariate techniques including correlation analysis, CA, and FA/PCA based on water quality parameters for 17 sites over 2017-2019, yielding PI values for primary factors. Site 10 indicated the highest parameter concentrations, and results of pearson's correlation analysis suggest that non-biodegradable organic matter had been distributed on the site. Five clusters were identified in order of descending pollution levels: I (Ib > Ia) > II (IIa > IIb) > III. Spatial variations started from sub-cluster Ib in which Daegu city and Geumho-river are joined. T-P, PO4-P, SS, COD, and TOC corresponded to VF 1 and 2, which were found to be principal components with strong influence on water quality. Sub-cluster Ib was strongly influenced by NO3-N and T-N compared to other clusters. According to the PIs, water quality pollution deteriorated due to non-biodegradable organic matter, nitrogen- and phosphorus-based nutrient salts in the middle and lower reaches, illustrating worsening water pollution due to inflows of anthropogenic sources on the Geumho-river, i.e., sewage and wastewater, discharged from Site 10, at which there is a concentration of urban, agricultural, and industrial areas.

• Journal of Environmental Science International
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• v.16 no.12
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• pp.1451-1462
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• 2007

Heavy metal concentrations in the soil were investigated for the abandoned Samkwang metal mine, Cheongyang-Gun, Chungnam Province, Korea. The concentrations of heavy metal(As, Cd, Cu, Ni, Pb, Zn) were determined in mine soils collected at the abandoned mine sites to obtain a general classification and specification of the pollution in this highly polluted region. The results estimated with the normal test and basis statistic on the central tendency and variation showed that the distribution of heavy metal concentration had significantly different at the range of all locations. The range of spatial distribution on the relationship of heavy metal concentration and pH was $4.8{\sim}8.8$ and heavy metal concentration on the type of land use was highest in forest land, and also Ni and Zn in farm and rice field showed the high concentration. The distribution of heavy metal concentration on the depth of a soil showed that the metal concentrations in subsoil were higher than of those in surface soil, while the concentration of Cu and Ni had no significant difference on the depth of soil. Results from the correlation analysis using the data except the extreme and unusual data revel that Zn-Cd(r=0.867), Zn-As(r=0.797), Zn-Pb(r=0.764), Cu-Cd(r=0.673), Cu-As(r=0.614) and Zn-Ni(r=0.605) were the most important parameters in assessing variations of heavy metal in soil. To discriminate pattern differences and similarities among samples, principal factor analysis(PFA) and cluster analysis(CF) were performed using a correlation matrix. This study suggests that PFA and CF techniques are useful tools for identification of important heavy metal and parameters. This study presents the necessity and usefulness of multivariate statistical assessment of complex databases in order to get better information about the quality of soil and gives the basis information to clean up the abandoned mine sites.

• Nuclear Engineering and Technology
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• v.54 no.11
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• pp.4253-4264
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• 2022

Since the implementation of the phosphate project in Bled El-Hadba (BEH) deposit, western region of Tébessa, no detailed study has been conducted to assess the natural radioactivity distribution and the associated radiological risk parameter for this open-pit mine. For the sake of determining a credible premining reference database for the region of interest, 21 samples were collected from different geological layers of the above-mentioned deposit. Gamma Spectrometry was applied for measuring radioactivity using a high resolution HPGe semiconductor detector. The obtained activity results have shown a significant broad variation in the radioactive contents for the different phosphate samples. The total average concentrations (in Bq·kg^-1) for ²²⁶Ra, ²³⁸U, ²³⁵U, ²³²Th and ⁴⁰K computed for the different type of phosphate layers were found to be 570 ± 169, 788 ± 280, 52 ± 18, 66 ± 6 and 81 ± 18 respectively. The mean activity concentrations of the measured radionuclides were compared to other regional and worldwide deposits. The ratios between the detected radioisotopes have been calculated for spatial distribution of natural radionuclides in the study area. Based on the aforementioned activity concentrations, the corresponding radiation hazard parameters were assessed. Correlations between the obtained parameters were drawn and a multivariate statistical analysis (Pearson Correlation, Cluster and Factor analysis) was carried out in order to identify the existing relationships.

• KCID journal
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• v.17 no.2
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• pp.17-27
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• 2010

In order to manage the water quality in reservoir, it is necessary to understand the temporal and spatial variation of reservoirs and to classify the reservoirs. In this research, agricultural reservoirs are classified according to physical characteristics (depth, residence time, shape of the reservoir etc) and water quality using multivatriate analysis (PCA and CA). CA (Cluster Analysis) method classify reservoirs into several groups as a similarity of the reservoirs, but it is difficult to indicate a full list to the one table. In case of PCA (Principle Component Analysis) method, it has the advantage for the classification on the reservoirs depending on the water quality similarity and also it is useful to analyze the relationship between related factors through correlation analysis. However PCA is limited to classify into several groups based on the characteristics of the reservoirs and each user should be classified as randomly subjective according to the relative position of the reservoir in the figure. In conclusions, compared to conventional reservoirs classification methods, both CA and PCA methods are considered to be a classification method that describes the nature of the reservoir well, but classification results has a restriction on use, so further research will be needed to complement.

• Journal of the Korean Data and Information Science Society
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• v.14 no.2
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• pp.289-301
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• 2003

In this paper, we propose Shewhart control chart and EWMA control chart using the autocorrelated data which are common in chemical and process industries and lead to increase the number of false alarms when conventional control charts are applied. The effect of autocorrelated data is modeled as a autoregressive process, and canonical analysis is used to reduce the dimensionality of the data set and find the canonical variables that explain as much of the data variation as possible. Charting statistics are constructed based on the residual vectors from the canonical variables which are uncorrelated over time, and the control charts for these statistics can attenuate the autocorrelation in the process data. The charting procedures are illustrated with a numerical example and simulation is conducted to investigate the performances of the proposed control charts.