• The KSFM Journal of Fluid Machinery
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• v.2 no.3 s.4
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• pp.17-23
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• 1999

In the present numerical analysis, investigation of the effect of blade loadings from design shape on the slip factor variation was studied. Both the Eckardt radial bladed impeller and the backswept impeller were analyzed. In addition, a new design of the blade profile was arbitrarily attempted to generate a center-loading pattern in the original backswept impeller. Three dimensional compressible Navier-Stokes flow analysis with the Baldwin-Lomax turbulence model was applied to get the numerical slip factor at each impeller exit plane using the mass-averaging technique. The numerical slip (actors are in good agreement with the experimental ones and the Wiesner's slip factors deviate further from the numerical and experimental ones in both backswept impellers. Deviation angles and meridional channel loadings are found in no relation with the trend of change of the slip factor. Blade-to-blade loadings in midspan location are, however, found to have a direct relationship, especially at the sections where maximum loadings we to be expected. That information can be utilized in establishing an improved expression for slip factors in the future.

• Magazine of the Korean Society of Agricultural Engineers
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• v.45 no.3
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• pp.94-102
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• 2003

A hydrologic and water quality monitoring network were established in the Balkan-reservoir watershed, which has 29.79 $km^2$ in size, to analyze the characteristics of pollutant loading from an agricultural small watershed. Soil type, land use, hydrologic soil group, population and livestock were also surveyed to make clear the pollutant sources and to calculate the pollutant loadings by the unit loading factor method which was proposed by the Ministry of Environment. From the 5-year hydrologic monitoring results, sub-watersheds located in the upstream of the reservoirs showed higher average runoff ratio. The calculated daily pollutant loadings by the unit loading factor method from HP#2 sub-watershed in the downstream of Balkan reservoir, were much greater than observed.

• Journal of Environmental Science International
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• v.5 no.1
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• pp.15-23
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• 1996

During the last two decades, many industrial complexes for heavy and chemical industries have been established along the Korean coastline, thereby increasing the pollution materials burden on the coastal environment of seawater. Masan Bay is one of the most polluted coastal areas in Korea and the main soures of pollutants are domestic and industrial wastewater from Masan, Changwon. This study was aimed to evaluate relationships among the physicochemical parameters in the bottom water of Masan bay and to examine environmental factors affecting to pollutions of seawater by factor analysis. 'rife factor loading, 1 is showed higher increasing inclination after 1989 year in station 1. The variance of pollutant materials is showed 43.7% in which the coastal inflow water is indicated external loadings(factor 1 : NO3--N, TN, factor 4 : SiO2-Si) corresponded to domestic sewage, industrial wastewater, and earth-sands in the bottom water of Masan bay And the internal loadings(factor 2 : SS, salinity, factor 3 . W.T., DO) are explained 33.8%'corresponded the phenomena of sedimentary layer and oxygen concentration. Therefore, The external loadings are explained by the higher factor pollutantal variance in Masan bay.

• Journal of Nutrition and Health
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• v.40 no.3
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• pp.259-269
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• 2007

Recently, dietary pattern analysis was emerged as an approach to examine the relationships between diet and risk of chronic diseases. This study was to identify groups with population who report similar dietary pattern in Korean genome epidemiology study (KoGES) and association with several chronic diseases. The cohort participants living in Ansung and Ansan (Gyeonggi province) were totally 10,038. Among those, 6,873 subjects with no missing values in food frequency questionnaire were included in this analysis. After combining 103 food items into 17 food groups, 4 dietary factors were obtained by factor analysis based on their weights. Factor 1 showed high factor loadings in vegetables, mushrooms, meats, fish, beverages, and oriental-cereals. Factor 2 had high factor loadings in vegetables, fruits, fish, and factor 3 had high factor loadings in cereal-oriental, cerial-western and snacks. Factor 4 showed positive high factor loadings in rice and Kimchi and negative factor loadings in mushrooms and milk and dairy products. Using factor scores of four factors, subjects were classified into 3 clusters by K-means clustering. We named those 'Rice and Kimchi eating' group, 'Contented eating' group, and 'Healthy and light eating' group depending on their eating characteristics. 'Rice and Kimchi eating' group showed high prevalence in men, farmers and 60s. 'Contented eating' group and 'Healthy and light eating' group had high prevalence in women, people living in urban area (Ansan Citizen), with high-school education and above, and a monthly income of one million won and more. 'Contented eating' group appeared lower distribution proportion in the sixties and 'Healthy and light eating' group does higher in the fifties. 'Contented eating' versus 'Rice and Kimchi eating', odds ratio for hypertension, diabetes, metabolic syndrome and obesity significantly decreased after adjusting age and sex (OR=0.64, 0.73, and 0.85 respectively, 95% CI). Although our results were from a cross-sectional study, these imply that the dietary patterns were related to diseases.

• Journal of Environmental Science International
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• v.12 no.3
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• pp.299-306
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• 2003

The purpose of this study is to investigate the characteristics of water quality in Jeju harbor and to estimate pollutant loadings discharged into Jeju Harbor. To know characteristics of water quality in Jeju harbor, and pollutant loadings of Sanzi river, we have investigated from August, 2000 to May, 2001. The results showed that the concentrations of COD, DIN and DIP were in the range of 1.00∼4.85 mg/L (mean 2.15 mg/L), 2.14∼74.0 $\mu\textrm{g}$-at/L(mean 12.20 $\mu\textrm{g}$-at/L) and 0.52∼4.00 $\mu\textrm{g}$-at/L(mean 1.18 $\mu\textrm{g}$-at/L), respectively. These values were under III class of seawater quality criteria. The ratio of nitrogen to phosphorus was lower than 16 except for Station 1 in Jeju harbor. Therefore, nitrogen was playing an important role in phytoplankton growth as limiting factor in Jeju harbor. The mean values of eutrophication index were exceeding 1, which was the eutrophication criteria. The results of estimating pollutant loadings at Sanzi river are 0.30 ton/day for COD, 300 kg/day for DIN and 18.0 kg/day for DIP, respectively.

• Journal of the Korean Institute of Landscape Architecture
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• v.29 no.1
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• pp.22-31
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• 2001

The purpose of this study is to compare calculated pollutant loadings using pollutant load unit factors and vector type coverage, and expected mean concentration(EMC) and raster type of digital elevation model(DEM). This study is also focusing on comparison of the advantages and the disadvantages of the two methods, and seeking for a method of calculation of pollutant loadings using DEM. Estimation of pollutant inputs using pollutant load unit factors has limitations in identifying seasonal variations of pollutant loadings. Seasonal changes of runoffs should be considered in the calculation of pollutant loadings from catchments into reservoirs. Evaluation of pollutant inputs using runoff-coefficient and EMC can overcome these drawbacks. Proper EMC and runoff-coefficient values for the Koeup stream catchments of the Koheung estuarine lake were drawn from review of related papers. Arc/Info was employed to establish database of spatial and attribute data of point and non-point pollutant sources and characteristics of the catchments. ArcView was used to calculate point and non-point pollutant loadings. Pollutant loads estimated with either unit factors-coverages, i.e., pollutant load unit factors and vector coverages f point sources and land use, or EMC and digital elevation mode(DEM) were compared with stream monitoring loads. We have found that some differences were shown between monitoring results and estimated loads by Unit Factors-Coverage and EMC-DEM. Monthly variations of pollutant loads evaluated with EMC-DEM were similar to those with monitoring result. The method using EMC-DEM can calculate accumulated flows and pollutant loads and can be utilized to identify stream networks. A future research on correcting the difference between vector type stream using flow direction grid and digitalizing vector type should be conducted in order to obtain more exact calculation of pollutant loadings.

• The Korean Journal of Applied Statistics
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• v.26 no.6
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• pp.933-942
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• 2013

Common factor analysis and principal component analysis represent two technically distinctive approaches to exploratory factor analysis. Much of the psychometric literature recommends the use of common factor analysis instead of principal component analysis. Nonetheless, factor analysts use principal component analysis more frequently because they believe that principal component analysis could yield (relatively) less accurate estimates of factor loadings compared to common factor analysis but most often produce similar pattern of factor loadings, leading to essentially the same factor interpretations. A simulation study is conducted to evaluate the relative performance of these two approaches in terms of factor pattern recovery under different experimental conditions of sample size, overdetermination, and communality.The results show that principal component analysis performs better in factor recovery with small sample sizes (below 200). It was further shown that this tendency is more prominent when there are a small number of variables per factor. The present results are of practical use for factor analysts in the field of marketing and the social sciences.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.637-642
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• 2000

In order to control the water quality of freshwater lake in tidal reclaimed land, it is needed to evaluate accurate amount of pollutant loadings from reclaimed paddy field. This study was carried out to investigate the pollutant loading from a reclaimed paddy field. Site of the study was a paddy field located in Taeho reclaimed land, with an areas of 38.5 hectares. The runoff loadings of Total-Nitrogen, Total-Phosphorus, and Chemical Oxygen Demand were 49.5 kg/㏊/yr, 3.2 kg/㏊/yr and 154.0 kg/㏊/yr, respectively. The runoff loadings in Total-Nitrogen and Total-Phosphorus from this study were much higher values than the pollutant load factor of Total-Nitrogen and Total-Phosphorus from the paddy field published by the Ministry of Environment.

• Journal of Korean Society on Water Environment
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• v.23 no.1
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• pp.161-168
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• 2007

The main aim of this work is focus on the Geum river water quality evaluation of pollution data obtained by monitoring measurement during the period 2001-2005. The complex data matrix 19 (entire monitoring stations)*13 (parameters), 60 (month)*13 (parameters) and 20 (season)*13 (parameters) were treated with different multivariate techniques such as factor analysis/principal component analysis (FA/PCA). FA/PCA identified two factor (19*13) classified pollutant Loading factor (BOD, COD, pH, Cond, T-N, T-P, $NH_3$-N, $NO_3$-N, $PO_4$-P, Chl-a), seasonal factor (water temp, SS) and three Factor (60*13, 20*13) classified pollutant Loading factor (BOD, COD, Cond, T-N, T-P, $NH_3$-N, $NO_3$-N, $PO_4$-P), seasonal factor (water temp, SS) and metabolic factor (Chl-a, pH). Loadings of pollutant factor is potent influence main factor in the Geum river which is explained by loadings of pollutant factor at whole sampling stations (71.16%), month (52.75%) and season (56.57%) of main water quality stations. Result of this study is that pollutant loading factor is affected at Gongju 1, 2, Buyeo 1, 2, Gangkyeong, Yeongi stations by entire stations and entire month (Gongju 1, Cheongwon stations), April, May, July and August (buyeo 1) by month. Also the pollutant Loading factor is season gives an influence in winter (Gongju 1, buyeo 1) from main sampling stations, but Cheongwon characteristic is non-seasonal influenced. This study presents necessity and usefulness of multivariate statistic techniques for evaluation and interpretation of large complex data set with a view to get better information data effective management of water sources.

• Nutrition Research and Practice
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• v.9 no.2
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• pp.199-206
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• 2015

BACKGROUND/OBJECTIVE: Even though the prevalence of metabolic syndrome in adolescents is increasing, little is presently known about this syndrome in adolescents. This study aimed to cluster metabolic risk factors as well as examine the associations between identified patterns and nutrient intake using data from the Korean National Health Examination and Nutritional Assessment (KNHANES). SUBJECTS/METHODS: A total of 2,958 subjects aged 10 to 18 years along with both biochemical and dietary data information were obtained from KNHANES 2007-2010. Six components of metabolic syndrome were used to identify any patterns via factor analysis. Individuals were categorized into quartile groups according to their pattern score. RESULTS: Three clustering patterns with high loadings were identified and named as follows: 1) high blood pressure, 2) dyslipidemia, and 3) glucose abnormality patterns. The high blood pressure pattern showed high loadings of systolic and diastolic blood pressures, the dyslipidemia pattern showed high loadings of triglyceride and HDL-cholesterol levels, and the glucose abnormality pattern showed high loadings of fasting blood glucose levels. Intakes of fat and riboflavin were significantly decreased, whereas those of sodium and niacin were significantly increased across the quartiles in the dyslipidemia pattern. No nutrient intake except that of thiamin was significantly associated with the high blood pressure or glucose abnormality pattern. CONCLUSION: Our findings show that metabolic syndrome risk factors in the Korean adolescent population are characterized by three distinct patterns, which are differentially associated with dietary factors. Characterizing metabolic risk factors and providing specific dietary guidelines for target groups are important.