• 대한약침학회지
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• 제12권4호
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• pp.33-50
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• 2009

Objectives : This study was conducted to confirm validation and stability of concentration analysis method of pure melittin (Sweet Bee Venom-Sweet BV) extracted from the bee venom by utilizing protein isolation method of gel filtration. Methods : All experiments were conducted at Biotoxtech, a non-clinical studies authorized institution, under the regulations of Good Laboratory Practice (GLP). Standard solutions of melittin (SIGMA, USA) and test substances were dispensed and were analyzed with HPLC for Sweet BV to secure the validation of analysis. Results : 1. Measurement of system suitability of Sweet BV satisfied criterion of below 3%. 2. Confirming Linearity of Sweet BV in 10-200${\mu}g/m\ell$ solution yielded correlation coefficient (r) of 0.995 and accuracy of 85-115% which satisfy criterion. 3. Measurement of Specificity of Sweet BV didn't yield any substance affecting the peak of test substances, but detected at 21.22min verified as the test substance. 4. Confirming Intra-day of Sweet BV, accuracy and precision of 0.1, 100${\mu}g/m\ell$ were 105.70, 95.81 and 0.66, 0.73, respectively, satisfying both criteria of accuracy (85-115%) and precision (within 10%). 5. To measure Stability in autosampler, all samples used in Intra-day reproducibility sat in the autosampler for five hours and were re-analyzed. Both variability and precision satisfied the criteria. 6. Homogeneity of Sweet BV (0.1, 100${\mu}g/m\ell$) at upper, middle, and lower layers all satisfied the accuracy and precision criteria. 7. Stability of Sweet BV (0.1, 100${\mu}g/m\ell$) at room temperature for four hours and refrigerated for 7 days all satisfied the criterion. 8. For the measurement of Quality control, QC samples measured on the first and eighth day all satisfied accuracy and precision criteria. Conclusion : Above experiment data satisfies validation and stability of concentration analysis method of Sweet BV.

• Journal of Pharmaceutical Investigation
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• 제21권3호
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• pp.179-188
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• 1991

An HPLC assay method of a drug to be applied to the pharmacokinetic studies of the drug should be completely validated. The validation process for an HPLC assay method in a biological sample was discussed using the data obtained from the development of HPLC method for the simultaneous quantitation of verapamil and norverapamil in human serum. The validation criteria included were specificity, linearity, accuracy, precision, sensitivity, recovery, drug stability, and ruggedness of an assay method.

• Geomechanics and Engineering
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• 제18권5호
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• pp.493-502
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• 2019

Internal stability is an important safety issue for levees, embankments, and other earthen structures. Since a large part of the world's population lives near oceans, lakes and rivers, floods resulting from breaching of dams can lead to devastating disasters with tremendous loss of life and property, especially in densely populated areas. There are some main factors that affect the internal stability of dams, levees and other earthen structures, such as the erodibility of the soil, the water velocity inside the soil mass and the geometry of the earthen structure, etc. Thus, the mechanism of internal erosion and stability of soils is very complicated and it is vital to investigate the assessment methods of internal stability of soils in embankment dams and their foundations. This paper presents an improved support vector machine (SVM) model to predict the internal stability of soils. The grid search algorithm (GSA) is employed to find the optimal parameters of SVM firstly, and then the cross - validation (CV) method is employed to estimate the classification accuracy of the GSA-SVM model. Two examples of internal stability of soils are presented to validate the predictive capability of the proposed GSA-SVM model. In addition to verify the effectiveness of the proposed GSA-SVM model, the predictions from the proposed GSA-SVM model were compared with those from the traditional back propagation neural network (BPNN) model. The results showed that the proposed GSA-SVM model is a feasible and efficient tool for assessing the internal stability of soils with high accuracy.

• 대한조선학회논문집
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• 제49권1호
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• pp.52-59
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• 2012

Among many factors to be considered for higher safety level requirements, the hull stability in intact and damaged conditions in seaways is of utmost importance. Since the assessment of a damaged ship is complicated due to the highly non-linear behavior, it is widely acknowledged that computational fluid dynamics (CFD) methods are one of the most feasible approaches. Although many research activities are being reported on the damaged ship stability recently, most of them are not designed for validation of CFD studies. In this study, well-designed model tests were performed to build a CFD validation database, which is essential in developing better CFD methods for the damage stability assessment. The geometry of the damaged compartment and test conditions were determined based on preliminary CFD simulations. Free roll decay tests in calm water with both intact and damaged ships were performed and the roll motion characteristics were compared. The damaged ship showed a larger roll damping coefficient and more rapid decrease of roll amplitude than the intact ship. The primary reason of these efforts can be explained by the movement of the flooded water.

• International Journal of Naval Architecture and Ocean Engineering
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• 제4권2호
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• pp.172-181
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• 2012

One of the most critical issues in naval architecture these days is the operational safety. Among many factors to be considered for higher safety level requirements, the hull stability in intact and damaged conditions is the first to ensure for both commercial and military vessels. Unlike the intact stability cases, the assessment of the damaged ship stability is very complicated physical phenomena. Therefore it is widely acknowledged that computational fluid dynamics (CFD) methods are one of most feasible approaches. In order to develop better CFD methods for damaged ship stability assessment, it is essential to perform well-designed model tests and to build a database for CFD validation. In the present study, free roll decay tests in calm water with both intact and damaged ships were performed and six degree-of-freedom (6DOF) motion responses of intact ship in regular waves were measured. Through the free roll decay tests, the effects of the flooding water on the roll decay motion of a ship were investigated. Through the model tests in regular waves, the database that provides 6DOF motion responses of intact ship was established.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.1225-1226
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• 2011

• The Journal of Asian Finance, Economics and Business
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• 제8권3호
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• pp.1-10
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• 2021

This study examines the dynamic pattern of the exchange rate volatilities of the ASEAN-5 currencies from January 2006 to August 2020. The exchange rates applied in this study comprise bilateral and effective exchange rates in order to investigate the influence of the US dollar on the stability of the ASEAN-5 currencies. Since a volatility model employed in this study is a natural cubic spline volatility model, the Monte Carlo simulation is consequently conducted to determine an appropriate criterion to select a number of quantile knots for this model. The simulation results reveal that, among four candidate criteria, Generalized Cross-Validation is a suitable criterion for modeling the ASEAN-5 exchange rate volatilities. The estimated volatilities showed the inconstant dynamic patterns reflecting the uncertain exchange rate risk arising in international transactions. The bilateral exchange rate volatilities of the ASEAN-5 currencies to the US dollar are more variable than their corresponding effective exchange rate volatilities, indicating the influence of the US dollar on the stability of the ASEAN-5 currencies. The findings of this study suggest that the natural cubic spline volatility model with the quantile knots selected by Generalized Cross-Validation is practical and can be used to examine the dynamic patterns of the financial volatility.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.223.2-223.2
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• 2002

• Ocean Systems Engineering
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• 제9권2호
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• pp.157-177
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• 2019

Studies on motion response of a vessel is of great interest to researchers, since a long time. But intensive researches on stability of vessel during motion under dynamic conditions are few. A numerical model of vessel is developed and responses are analyzed in head, beam and quartering sea conditions. Variation of response amplitude operator (RAO) of vessel based on Strip Theory for different wave heights is plotted. Validation of results was done experimentally and numerical results was considered to obtain effect of damping on vessel stability. A scale model ratio of 1:125 was used which is suitable for dimensions of wave flume at National Institute of Technology Calicut. Stability chart are developed based on Mathieu's equation of stability. Ince-Strutt chart developed can help to capture variations of stability with damping.

• 약학회지
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• 제52권2호
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• pp.93-100
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• 2008

A liquid chromatographic method with tandom spectrometric detection (LC/MS/MS) for the simultaneous determination of doxifluridine and its active metabolite, 5-fluorouracil (5-FU) was developed over the concentration range of $5{\sim}2000$ ng/ml, respectively. Doxifluridine, 5-FU and internal standard, 5-chlorouracil (5-CU), were extracted from liver and intestine tissue via protein precipitation. Acetonitrile was used as the extraction solvent and the supernatant was evaporated and reconstructed in mobile phase. Optimum chromatographic separation was achieved on a Agilent Zorbax $C_{18}$ ($100\;mm{\times}2.1\;mm$, $3.5\;{\mu}m$) column with mobile phase run in isocratic with methanol : water (20 : 80, v/v). The flow rate was 0.2 ml/min with total cycle time of 5 min. The lower limit of quantification was validated at 5.0 ng/ml of liver and intestine tissue, for both doxifluridine and 5-FU, respectively. The intra-day and inter-day precision and accuracy of quality control (QC) samples were <11% coefficient of variation and <7% relative error from theoretical concentration for both analytes. In addition, the special designed stability study was performed, because the metabolism of doxifluridine occurs spontaneously even in ice bath for monkey liver. The stability of doxifluridine in liver and intestine of monkey and beagle dog was compared. It was found that bioanalytical validation could not be performed for the monkey liver; however, beagle dog's liver has relatively low speed of metabolism compared to monkey liver and instead of monkey liver, beagle dog's liver could be used for the validation. Bioanalytical validation could be performed in monkey intestine. Eventually, this developed method for liver and intestine will be useful in support of the toxicokinetic and pharmacokinetic studies of doxifluridine and 5-FU.