• 유체기계공업학회:학술대회논문집
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• 2002.12a
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• pp.209-214
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• 2002

The present study is to compare the performance of turbulence models in the analysis of the complex flowfield of an axial flow compressor. Baldwin-Lomax turbulence model and k-$\omega$ turbulence model were selected for the comparison. The thin-layer Wavier-Stokes equation was calculated by explicit, finite-difference numerical scheme. A spatially-varying time-step and an implicit residual smoothing were used to improve convergence. Experimental measurements for NASA rotor 37 were cited fer the comparison with numerical data. The compared two turbulence models gave similar performance over all except for total pressure.

• Journal of Astronomy and Space Sciences
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• v.21 no.3
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• pp.191-200
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• 2004

The accuracy of CCD observations obtained at the Korean 1.8m telescope has been studied. Seventeen comparison stars in the vicinity of the cataclysmic variable BG CMi have been measured. The 'artificial' star has been used instead of the 'control' star, what made possible to increase accuracy estimates by a factor of 1.3-2.1 times for 'good' and 'cloudy' nights, respectively. The algorithm of iterative determination of accuracy and weights of few comparison stars contributing to the artificial star, has been presented. The accuracy estimates for 13-mag stars are around $0.^m002$ mag for exposure times of 30 sec.

• Health Policy and Management
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• v.9 no.1
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• pp.178-200
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• 1999

The present study purports to examine the relationship between organizational and occupational commitment and to find the determinats of occupational commitment for salaried physicians working in hospitals. For the purpose of comparison, those of hospital administrative and clerical employees were also investigated for the purpose of comparison. The sample for jthis study consists of 77 salaried physicicas and 185 administrative and clerical employees (comparison group) from two university hospitals in Seoul and its surburbs. Data were collected by questionnaires and analyzed using ANOVA, ANCOVA, and multiple regression. The main findings of the study are as follows : 1) organizational and occupational commitment were positively correlated for both salaried physicans and clerical employees; 2) the variable of job variety had a positive impact on occupational commitment for salaried physicians; and 3) three variables of fairness of rewards, autonomy, and job variety had positive impacts for clerical employees. These findings were discussed and implications for organizational analysts and hospital administrators were suggested.

• The Korean Journal of Applied Statistics
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• v.25 no.3
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• pp.531-541
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• 2012

In this study, we consider various methods to estimate the weights of a pairwise comparison matrix in the Analytic Hierarchy Process widely applied in various decision-making fields. This paper uses a data dependent simulation to evaluate the statistical accuracy, minimum violation and minimum norm of the obtaining weight methods from a reciprocal symmetric matrix. No method dominates others in all criteria. Least squares methods perform best in point of mean squared errors; however, the eigenvectors method has an advantage in the minimum norm.

• Communications for Statistical Applications and Methods
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• v.25 no.2
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• pp.185-197
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• 2018

Measuring market fear is an important way of understanding fundamental economic phenomena related to financial crises. There have been several approaches to measure market fear or panic level in a financial market. Recently, herd behavior has gained its popularity as important economic phenomena explaining the fear in the financial market. In this paper, we investigate herd behavior in global stock markets with a focus on intercontinental comparison. While various risk measures are available for the detection of herd behavior in the market, we use the standardized herd behavior index in Dhaene et al. (Insurance: Mathematics and Economics, 50, 357-370, 2012b) and Lee and Ahn (Dependence Modeling, 5, 316-329, 2017) for the comparison of herd behaviors in global stock markets. A global stock market data from Morgan Stanley Capital International is used to study herd behavior especially during periods of financial crises.

• Proceedings of the Safety Management and Science Conference
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• 2007.11a
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• pp.263-268
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• 2007

The main objective of this study is to provide numerical guideline for size establishment of safety shoes about adult men(over 20 years) compared to physical standards of nation (report published in 1997). The sample for this work was chosen from data which were collected and measured by Size Korea during two years (2003${\sim}$2004). In order to analyze and compare features of men's foot, analysis was performed about 1,685 subjects on 2 parts such as foot length and foot circumference. For the specific comparison on foot size, Mollison's comparison graph was used. The result of this study can be applied in manufacturing and design of shoes and socks. Also, it will enable us to have fruitful information on considerable items during manufacturing and design of safety shoes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.3
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• pp.514-520
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• 1997

The purpose of this study is to provide the reference data for estimating body composition and developing equations for prediction of percent body fat. This study was designed of two aspects: Comparison of percent body fat measurements between two operators. comparison of percent body fat measurements among four instruments. Percent body fat of college girls(n=71) aged 18-24 was measured by skinfold thickness, near-infratred interactance(Futrex-5000), and bioelectrical impedance analysis (TBF-105, Spectrum II). All measurements were duplicated & measured by two operators. The results are summarized as follows: Percent body fat observed from two operators had no significant difference. There was significant difference from four instruments. However, we found close relation between Skinfold thickness & TBF-105, Spectrum II & Near-infrared interactance. Four instruments have several assumptions and limitations. Therefore, many researches for developing new equations are required for Korean people.

• Korean Parent-Child Health Journal
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• v.9 no.2
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• pp.140-149
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• 2006

Purpose: The current descriptive study examined the health and healthcare status of preschoolers in poverty group compared to those of comparison group. Method: Data were collected from 51 mothers in federal poverty group and 49 in low-income group and 200 mothers in normal income comparison group in one city. The instruments used for this study were Korean CBCL and health related questionnaire. Results: Public assistance group showed more low-birth-weight infants, developmental delay, and hospital admission experiences. Their compliance for vaccination and congenital metabolic disorder test were lower than those of comparison group. Preschoolers' behavior problems were not significantly different depending upon the income of the group. Conclusion: Preschoolers' health and healthcare status are affected by the socioeconomic characteristics of the family. It indicated an need for anticipatory guidance and early intervention that might help to prevent or ameliorate potential health problems in poverty.

• International Journal of Oral Biology
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• v.36 no.4
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• pp.163-166
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• 2011

Oral viridans streptococci are recognized as one of the etiological agents of a variety of infectious diseases such as dental caries and infective endocarditis. Although antimicrobial susceptibility tests for these fastidious bacterial species are now established and standardized, a comparison between the broth microdilution and broth macrodilution tests has not previously been performed. This comparison was performed in the present study using the tests adopted by the Clinical and Laboratory Standards Institute (CLSI) and seven clinical isolates of oral viridans streptococcal strains. A modified broth macrodilution susceptibility test method was also included in this analysis, in which the media was not supplemented with horse blood. The susceptibility interpretation category agreements were measured at 83% (broth microdilution versus broth macrodilution) and 71% (broth microdilution versus modified broth macrodilution). The interpretation category agreement between the broth macrodilution and modified broth macrodilution tests was also 83%. These data indicate that the interpretation of antibiotic susceptibility test results for oral viridans streptococci are influenced by the methods used.

• Journal of the Korean Solar Energy Society
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• v.37 no.3
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• pp.23-32
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• 2017

This paper presents losses comparison and analysis results for different types of fault modes of grid-connected photovoltaic system generated for long-term operation. The approach of losses comparison and analysis by faults is to identify relationship between measured and estimated values of five loss factors which are quantified from irradiance to system output power. This paper presents the symptom results for faults such as snow, shading, sensor defect, blackout, soiling and so on from three years or more monitored data. These results will indicate that it is useful to develop fault detection and diagnosis tool to enhance capacity factor and save operation and maintenance cost of grid-connected photovoltaic system in the field.