• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1998년도 제27회 춘계학술대회
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• pp.335-341
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• 1998

In this study, the dynamic characteritics in various loading methods for wear tester were investigated experimentally. As for the dead-weight, the pneumatic, and the hydraulic method, the load control performance against external disturbances was estimated under the several loading conditions like the different sliding speed, the varied normal load, and the misaligument. The hydraulic loading method showed the most stable loading performance of all the loading methods in the experiment.

• 한국대기환경학회지
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• 제18권4호
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• pp.285-295
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• 2002

In this study, several types of gravimetric methods (such as high, medium, low, and ultra low volume sampling methods) were applied to determine suspended particulate matter concentrations in both ambient and indoor environments. Comparative evaluations were undertaken with SPM data obtained using a variety of samplers (TSP, PM10, and PM4.0) at different sampling flow rates. Correlation coefficients between TSP and PM10 concentrations measured at different flow rates fell in the range of 0.73∼0.94 (n=40). In addition, correlation coefficients for PM concentrations measured by different TSP samplers were in the range of 0.90∼0.95 (n=36 or n=38), while 0.77∼0.91 (n=38) for PM10 samplers. Correlation analysis was also conducted on indoor monitoring data that were measured using ultra-low-volume samplers at both different or identical flow rates. The correlation coefficients were in the range of 0.98∼0.99 (n=38) between TSP and TSP and 0.92∼0.94 (n=38) between TSP and PM10. The mean ratio for high volume PM10 to TSP concentration that was monitored at identical flow rates in the ambient air appeared to be 0.72. The mean ratios of PM10 to TSP and PM4.0 to TSP observed with identical flow rates at indoor environments were 0.47 and 0.40. The results of this study may provide empirical information concerning the compatability of aerosol data obtained by gravimetric sampling methods at different flow rates.

• 대한본초학회지
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• 제33권1호
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• pp.85-91
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• 2018

Objectives : This study was carried out to evaluate the quality of different drying methods and different roots(primary root and lateral root) of Angelica gigas Nakai. Methods : The experimental method was performed according to the Korea Pharmacopoea Eleventh edition (KP11). Loss on drying, ash, acid insoluble ash, ethanol extract, nodakenin and total decursin contents were tested to evaluate the quality of root tissue of Angelica gigas Nakai. In addition, the treatment of different root parts were prepared in two groups of washing dry process and natural dry process. Results : In comparison of dry processing methods, total contents of nodakenin and total decursin in the primary root and lateral root through washing dry process were ranged from 3.55 to 4.09% and from 5.18 to 6.13%, respectively. And also, those of roots from the natural dry process were from 4.36 to 6.22% and from 6.28 to 8.34%, respectively. In the washing dry process and natural dry process methods, 47.9% and 22.3% higher amount of nodakenin and total decursin were measured in lateral root compared to primary root. In common, lateral roots accumulated higher contents of nodakenin and total decursin compared to primary roots, and samples drying processed with natural dry process compared to washing dry process method contained higher amount of compounds. Conclusions : We sincerely hope that this study will be contributed to the standardization and quality control of Angelica Gigas Root.

• 한국식품저장유통학회지
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• 제6권1호
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• pp.61-65
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• 1999

This study was carried out to investigate change in the components according to drying methods of jujube. Raw jujube was dried with five methods such as sun-drying, hot-air drying after pretreated with sunlight, blanching, microwave treatment, respectively. The contents of soluble sugar and protein in sun-dried jujube were higher than those of other drying methods. The free sugars of dried jujube were consisted of sucrose, glucose and fructose. And the contents of free sugar was not different by drying methods. The major organic acids of dried jujube were oxalic acid, citric acid and malic acid. The contents of glutamic acid, glycine and alanine were higher than those of other amino acids, and the content of each amino acid was not different by drying methods.

• 한국경영과학회지
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• 제25권4호
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• pp.1-14
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• 2000

The methods of sensitivity analysis for linear programming can be classified in two types: sensitivity analysis using an optimal solution, and sensitivity analysis using an approximate optimal solution. As the methods of sensitivity analysis using an optimal solution, there are three sensitivity analysis methods: sensitivity analysis using an optimal basis, positive sensitivity analysis, and optimal partition sensitivity analysis. Since they may provide different characteristic regions under degeneracy, it is not easy to understand and apply the results of the three methods. In this paper, we propose a generalized sensitivity analysis that can integrate the three existing methods of sensitivity analysis. When a right-hand side or a cost coefficient is perturbed, the generalized sensitivity analysis gives different characteristic regions according to the controlling index set that denotes the set of variables allowed to have positive values in optimal solutions to the perturbed problem. We show that the three existing sensitivity analysis methods are special cases of the generalized sensitivity analysis, and present some properties of the generalized sensitivity analysis.

• 대한화학회지
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• 제57권1호
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• pp.20-24
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• 2013

The effect of the DFT methods and basis sets on harmine molecule has been investigated. 26 DFT methods with 6 basis sets were used. Two main comparison chosen DFT methods in this work has been investigated. It is concluded that this contribution is very important and cannot be neglected. In the following analysis, changes in energy levels were investigated by two different methods. Considering a specific basis set, changes in energy levels were obtained using different DFT methods. A specific DFT method is chosen and changes in energy levels have been investigated by means of various basis sets. Effect of the choice of basis sets on geometrical parameters on harmine molecule has also been investigated.

• International Journal of Naval Architecture and Ocean Engineering
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• 제3권3호
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• pp.159-173
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• 2011

The two different numerical approaches for solving the nonlinear ship wave problem are discussed in the present paper. One is based on a panel method, which neglects the viscous effects. The other is based on a finite volume method, which take into account the viscous effects by solving RANS equations. Focus is laid upon on the advantages and disadvantages of two methods. The developed methods are applied to calculating the flow around Series 60 hull to validate the performance of the present nonlinear methods. Although the two methods employ quite different numerical approaches, the calculated wave patterns from both methods show good agreements with the experiments. However the potential method simu-lates the global wave pattern accurately, while the viscous method shows better performance for the local wave prediction near a ship.

• 한국토양비료학회지
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• 제47권6호
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• pp.518-524
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• 2014

Heavy metal pollution in agricultural field near at the abandoned metal mines has been a critical issue in Korea. In particular, bioaccumulation in plants can have detrimental effect on human health. Main objective of this research was to examine arsenic (As) concentration in soil with varied extraction methods and to determine bioaccumulation and biological transfer factor in different crops. Results showed that bioaccumulation ratio of As for total contents in soil was ordered leafy and stem vegetables (1.19%) > fruit bearing vegetables (0.79%) > pulses (0.40%) > root vegetables (0.36%) with different crop species. Among 6 different extraction methods, all of extraction methods showed high correlation ($R^2=0.87-0.97$) except DTPA ($R^2=0.25$) when comparing As concentration in soil extracted with different extractants and As concentration in each crops. Calculated biological transfer factor was ranged 0.002-0.018 depending on crop species. Overall, concentration of As in crops can be varied and best management practice for minimizing bioaccumulation of As should be considered depending on crop species.

• 한국식품영양과학회지
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• 제30권2호
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• pp.256-260
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• 2001

This study was carried out to investigate effect of ultrasonic treatment on the quality of frying chicken meat. Moisture content of ultrasonic treated leg meat was lowest to 59.7%, moisture content of breast meat was higher than leg meat and protein content of control was higher than ultrasonic treatment. Fat content of ultrasonic treatment was higher than control and leg meat was higher than breast meat. Hunter's L (lightness) and a (redness)-value was not different between frying methods, but L-value of breast meat and a-value of leg meat was higher than leg and breast meat, respectively. Hunter's b (yellowness)-value was not different among frying chicken meats. Frying loss of ultrasonic treatment was significantly lower than control, water holding capacity was higher than control. VBN content of ultrasonic treatment was comparatively higher than control, TBA number of ultrasonic treatment was highest to 0.78mg malonaldehyde/kg. Hardness, springiness and cohesiveness of frying chicken meat was not different between frying methods, but difference of chicken muscle parts were significantly showed. Chewiness was not different among frying chicken meats and shear force value of control breast meat was lowest to 1.9kg. In case of sensory score, aroma and taste of frying chicken meat were out different between frying methods, but texture, juiciness and palatability of ultrasonic treatment were higher than control and that of breast meat were higher than leg meat.

• Journal of Animal Science and Technology
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• 제58권1호
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• pp.1.1-1.6
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• 2016

Background: Genotype imputation is an important process of predicting unknown genotypes, which uses reference population with dense genotypes to predict missing genotypes for both human and animal genetic variations at a low cost. Machine learning methods specially boosting methods have been used in genetic studies to explore the underlying genetic profile of disease and build models capable of predicting missing values of a marker. Methods: In this study strategies and factors affecting the imputation accuracy of parent-offspring trios compared from lower-density SNP panels (5 K) to high density (10 K) SNP panel using three different Boosting methods namely TotalBoost (TB), LogitBoost (LB) and AdaBoost (AB). The methods employed using simulated data to impute the un-typed SNPs in parent-offspring trios. Four different datasets of G1 (100 trios with 5 k SNPs), G2 (100 trios with 10 k SNPs), G3 (500 trios with 5 k SNPs), and G4 (500 trio with 10 k SNPs) were simulated. In four datasets all parents were genotyped completely, and offspring genotyped with a lower density panel. Results: Comparison of the three methods for imputation showed that the LB outperformed AB and TB for imputation accuracy. The time of computation were different between methods. The AB was the fastest algorithm. The higher SNP densities resulted the increase of the accuracy of imputation. Larger trios (i.e. 500) was better for performance of LB and TB. Conclusions: The conclusion is that the three methods do well in terms of imputation accuracy also the dense chip is recommended for imputation of parent-offspring trios.