• Journal of Korea Foundry Society
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• v.10 no.5
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• pp.408-416
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• 1990

The application of this new design approach called fracture mechanics allow one to determine the maximum allowable stress from the knowledge of the largest expected flow size and the plane strain fracture toughness of a material. In this study we examined the relation between retained austenite, mechanical property and fracture toughness accompanied by austempering heat treatment. Fracture toughness values and retained austenite volume were higher with the ADI(austempered ductile iron) which were austempered at $380^{\circ}C$ than austempered at $320^{\circ}C$. Additionally, fracture toughness values were increased for 1~2 hour austempering time but it was slowly decreased for 5 hour ADI maintaining the predominant fracture toughness($K_{IC}:83MPa{\sqrt{m}}$) is obtained following condition, namely, austempering temperature and time ($380^{\circ}C$ and 1 hour).

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.8
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• pp.1071-1078
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• 2006

Three buffalo populations viz. Bhadawari, Tarai and local buffaloes of Kerala were genotyped using 24 heterologous polymorphic microsatellite loci. A total of 140 alleles were observed with an average observed heterozygosity of 0.63. All the loci were neutral and 18 out of the 24 loci were in Hardy Weinberg Equilibrium. The $F_{IS}$ values (estimate of inbreeding) for 16 loci in all the three populations were negative. This indicated lack of population structure in the three populations. The effective number of immigrants was 5.88 per generation between the Tarai and Bhadawari populations which was quite high suggesting substantial gene flow. The genetic distances revealed closeness between the Tarai and Bhadawari populations which was expected from geographical contiguity. The FST values were not significantly different from zero showing no population differentiation. The Correspondence Analysis based on the allelic frequency data clustered the majority of the Tarai and Bhadawari individuals as an admixture.

• Journal of Astronomy and Space Sciences
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• v.17 no.2
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• pp.295-308
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• 2000

OSMI(Ocean Scanning Multi-Spectral Imager) raw image data(Level 0) were acquired and radiometrically corrected. We have applied two methods, using solar & dark calibration data from OSMI sensor and comparing with the SeaWiFS data, to the radiometric correction of OSMI raw image data. First, we could get the values of the gain and the offset for each pixel and each band from comparing the solar & dark calibration data with the solar input radiance values, calculated from the transmittance, BRDF (Bidirectional Reflectance Distribution Function) and the solar incidence angle($\beta$, $\theta$) of OSMI sensor. Applying this calibration data to OSMI raw image data, we got the two odd results, the lower value of the radiometric corrected image data than the expected value, and the Venetian Blind Effect in the radiometric corrected image data. Second, we could get the reasonable results from comparing OSMI raw image data with the SeaWiFS data, and get a new problem of OSMI sensor.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.814-818
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• 2003

This paper deals with the application of numerical differentiation in free vibration analysis. In the free vibration analysis, the derivative values of the given function are certainly used in calculation of structural parameters. For deriving the derivative values, both the time and labor are needed when the structures consist of non-linear geometries such as arches or curved beams. From this viewpoint, the numerical differentiation scheme is applied into the free vibration analysis. The numerical results obtained from the numerical differentiations are agreed very well with those obtained from the exact derivatives by analytical method. It is expected that the numerical differentiations can be utilized practically in the free vibration analysis.

• Journal of Korean Society on Water Environment
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• v.25 no.4
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• pp.606-614
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• 2009

To evaluate the biological water quality, diatom-based biological indices (DAIpo and TDI) were examined in the Sum-River and the Dal-stream. Having BOD concentrations below $2mg{\cdot}L^{-1}$ in most sites, water quality of both rivers was good. The DAIpo and TDI values ranged from 29.8 to 91.4 and from 38.7 to 93.0 respectively. From the biological water quality assessment, DAIpo and TDI for both rivers displayed fair to fairly poor water quality levels. However, the two indices showed more polluted conditions than expected from the BOD vlaues. In addition, DAIpo, having wider range of differences, appears to be more sensitive to the change in water quality when compared to TDI values. Statistical analysis using principal component analysis showed that Nitzschia palea and Diatoma vulgare might not be the appropriate indicators due to their low correlations with other indicators.

• Proceedings of the Safety Management and Science Conference
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• 2000.11a
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• pp.251-254
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• 2000

The critical problem in dealing with multiple characteristics is how to compromise the conflict among the selected levels of the design parameters for each individual characteristic. In this study, First, Methodology using SN ratio optimized by univariate technique is proposed and a parameter design procedure to achieve the optimal compromise among several different response variables is developed. Second, to solve the issue on the optimal design for multiple quality characteristics, this study modelled the expected loss function with cross-product terms among the characteristics and derived range of the coefficients of the terms. The model will be used to determine the global optimal design parameters where there exists the conflict among the characteristics, which shows difference in optimal design parameters for the individual characteristics. Third, this paper propose a decision model to incorporates the values assigned by a group of experts on different factors in weighting decision of characteristic. Using this model, SN ratio of taguchi method for each of subjective factors as well as values of weights are used in this comprehensive method for weighting decision of characteristic.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.10a
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• pp.53-58
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• 2001

This paper deals with the application of numerical differentiation in the structural analysis. In the structural analysis, the derivative values of the given function are sometimes used in calculation of structural behaviors. For calculating the derivative values, both the time and labor are needed when the structures consist of non-linear geometries such as arches or curved beams. From this viewpoint the numerical differentiation scheme is applied into the structural analysis. The numerical results obtained from the numerical differentiation are agreed very well with those obtained from the exact derivatives by analytical method. It is expected that the numerical differentiation can be utilized practically in the structural analysis.

• Journal of Integrative Natural Science
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• v.9 no.3
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• pp.206-214
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• 2016

The basic goal of software development is to produce high quality software at low cost. Therefore, when to stop software testing and release the software product is a significant point in the software development. The software cost model is an effective tool used to help software developers control costs and determine the release time. In this paper, we discuss the cost model to apply all 6 models with consideration of time to remove errors, cost of removing each error and risk cost due to software failure. We show the impact of cost coefficients and parameter values on the expected total cost by changing the values and comparing the optimal release times.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.1
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• pp.63-68
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• 2007

The computations of an ultra-high degree associated Legendre functions and its first derivative up to degree and order of 10800 are reported. Not only the magnitude of orders for the ultra-high degree calculation is presented but the numerical stability and accuracy of the computed values are described in detail. The accuracy on the order of $10^{-25}\;and\;10^{-15}$ was obtained for the values of Legendre function and the first derivatives of Legendre functions, respectively. The computable highest degree and order of Legendre function in terms of latitudes and the linear relationship between the magnitude of the function with respect to degrees and orders is found. It is expected that the computed Legendre functions contribute in many geodetic and geophysical applications for simulations as well as theoretical verifications.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1993.06a
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• pp.1167-1170
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• 1993

We look at the problem of defuzzification in situations in which in addition to the usual fuzzy output of the controller there exists some ancillary restriction on the allowable defuzzified values. We provide two basic approaches to address this problem. In the first approach we enforce the restriction by selecting the defuzzified value through a random experiment in which the values which have nonzero probabilities are in the allowable region, this method is based on the RAGE defuzzification procedure and makes use of a nonmonotonic conjunction operator. The second approach which in the spirit of the commonly used methods, a kind of expected value, converts the problem to a constraint optimization problem.