• 유체기계공업학회:학술대회논문집
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• 2001.11a
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• pp.303-308
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• 2001

A rotating blade of steam turbines is designed using blade design system. To minimize the design time. quasi three dimensional flow analysis code is adopted to calculate blade section. The blade section lies on a streamline determined by previous steam turbine design procedures. The blade design system makes a transform of streamline coordinates, (m, r$\theta$), to (m', $\theta$) coordinates and all design procedure except 3 dimensional stack-up is performed in the coordinates. Each designed blade section is stacked-up and whole 3 dimensional blade can be modified by correcting 2D section, repeatly. The full 3D numerial analysis for the one stage including designed rotating blade will be performed later

• Proceedings of the IEEK Conference
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• 2000.07b
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• pp.685-688
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• 2000

In this paper, we used image information for the enhancement of Korean numeral speech recognition. First, a noisy environment was made by Gaussian generator at each 10 dB level and the generated signal was added to original Korean numeral speech. And then, the speech was analyzed to recognize Korean numeral speech. Speech through microphone was pre-emphasized with 0.95, Hamming window, autocorrelation and LPC analysis was used. Second, the image obtained by camera, was converted to gray level, autocorrelated, and analyzed using LPC algorithm, to which was applied in speech analysis, Finally, the Korean numerial speech recognition with image information was more ehnanced than speech-only, especially in ‘3’, ‘5’and ‘9’. As the same LPC algorithm and simple image management was used, additional computation a1gorithm like a filtering was not used, a total speech recognition algorithm was made simple.

• Journal of Ocean Engineering and Technology
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• v.14 no.2
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• pp.76-83
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• 2000

this paper was concentrated on the finite element formulation to solve boundary value problems by using the isotropic elasto-plastic damage constitutive model proposed previously(Noh, 2000) The plastic damage of ductile materials is generally accompanied by large plasticdeformation and strain. So nonlinearity problems induced by large deformation large rotation and large strain behaviors were dealt with using the nonlinear kinematics of elasto-plastic deformations based on the continuum mechanics. The elasto-plastic damage constitutive model was applied to the nonlinear finite element formulation process of Shin et al(1997) and an improved analysis model considering the all nonlinearities of structural behaviors is proposed. Finally to investigate the applicability and validity of the numerical model some numerial examples were considered.

• Journal of the Korean Geosynthetics Society
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• v.8 no.3
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• pp.17-23
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• 2009

Conventional methods of reinforced slope analysis based on the concept of limit equilibrium have been widely adopted mainly due to their simplicity and short computation time. But depending upon the assumptions on the inter-slice forces, the factor of safety resulting from the limit equilibrium method is not uniquely determined. This paper describes a method to calculate the factor of safely of a slope using a numerical analysis. Recently some useful analysis techniques (Strength reduction method and the stability method using stress fields) by numerical analysis are proposed and their theory and characteristics applications are studied and investigated with simple examples in this paper.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.11a
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• pp.137-142
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• 2004

Recently. the number of the use of Digital Photogrammetry is increasing, and photogrammetry instruments are developing rapidly and the pression is improving continuously. In this study, using the Rollei d7 metric that is a measurement digital camera which has capacity of keeping numerial value by itself and easy carrying, we analyze the 3 dimensional hydraulic experiment model. First, we calculated RMSE by carrying out bundle adjustment. Second, we try to find a effective 3D DEM with the Kriging Interpolation, Third make a comparative study the DEM of the Triangulation with the DEM of the close-range digital photogrammetry.

• Journal of the Society of Naval Architects of Korea
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• v.30 no.1
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• pp.145-156
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• 1993

An improved analysis model for material nonlinearity induced by elasto-plastic deformation and damage including large strain response was proposed. The elasto-plastic-damage constitutive model based on the continuum damage mechanics approach was adopted to overcome limitations of the conventional plastic theory, which can manage the anisotropic tonsorial damages evolved during time-independent plastic deformation process of materials. Updated Lagrangian finite element formulation for elasto-plastic damage coupling problem including large deformation, large rotation and large strain problems was completed to develop a numerical model which can predict all kinds of structural nonlinearities and damage rationally. Finally, a finite element analysis code for the 2-dimensional plane problem was developed and the applicability and validity of the numerical model was investigated through some numerial examples. Calculations showed reasonable results in both geometrical nonlinear problem due to large deformation and material nonlinearity including the damage effect.

• Journal of the Korean GEO-environmental Society
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• v.15 no.8
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• pp.51-58
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• 2014

In this research, the composite grounds including original clay and soil-cement were constructed for conducting uniaxial compression test. Strength and deformation properties were analysed using results of laboratory tests with variations of water content of clay, replacement ratio and cement content. Numerical simulation using 3D distinct element method was conducted for soil cement. For strength of composite ground that contains more than cement contents of 15 %, it is more effective to increase cement content than increase of replacement ratio. Strength and elastic modulus of composite ground could be predicted by regression equations using uniaxial compression strength of clay, cement content of soil cement and replacement ratio. For strength and elastic modulus of soil cement, which is most important things for predicting final strength and elastic modulus of composite ground, numerical simulation using the distinct element method adapted bonding model could be used to verify laboratory test, and predict strength and elastic modulus.

• Atmosphere
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• v.25 no.3
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• pp.529-541
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• 2015

Korea Institute of Atmospheric Prediction System (KIAPS) has been developing a global numerial prediction model and data assimilation system. We has implemented LETKF (Local Ensemble Transform Kalman Filter, Hunt et al., 2007) data assimilation system to NCAR CAM-SE (National Center for Atmospheric Research Community Atmosphere Model with Spectral Element dynamical core, Dennis et al., 2012) that has cubed-sphere grid, known as the same grid system of KIAPS Integrated Model (KIM) now developing. In this study, we have assimilated Global Positioning System Radio Occultation (GPS-RO) bending angle measurements in addition to conventional data within ensemble-based data assimilation system. Before assimilating bending angle data, we performed a vertical unit conversion. The information of vertical localization for GPS-RO data is given by the unit of meter, but the vertical localization method in the LETKF system is based on pressure unit. Therefore, with a clever conversion of the vertical information, we have conducted experiments to search for the best vertical localization scale on GPS-RO data under the Observing System Simulation Experiments (OSSEs). As a result, we found the optimal setting of vertical localization for the GPS-RO bending angle data assimilation. We plan to apply the selected localization strategy to the LETKF system implemented to KIM which is expected to give better analysis of GPS-RO data assimilation due to much higher model top.