• 한국전산유체공학회:학술대회논문집
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• 1996.05a
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• pp.46-51
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• 1996

The flow field around a three dimensional minivan-like body has been simulated. This study solves 3-D unsteady incompressible Navier-Stokes equations on a non-orthogonal curvilinear coordinate system using second-order accurate schemes for the time derivatives, and third/second-order scheme for the spatial derivatives. The Marker-and-Cell concept is applied to efficiently solve continuity equation. The fourth -order artificial damping is added to the continuity equation for numerical stability. A H-H type multi-block grid system is generated around a three dimensional minivan-like body. Turbulent flows have been modeled by the Baldwin-Lomax turbulent model. The simulation shows three dimensional vortex-pair just behind body. And the flow separation is also observed the rear of the body. It has concluded that the results of present study properly agree with physical flow phenomena.

• Journal of KSNVE
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• v.3 no.4
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• pp.353-359
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• 1993

In this study, the Taylor-Galerkin method is modified to take into consideration the third order term in the Taylor series of the fundamental variable. In the Taylor-Galerkin method, after expressing the governing equation of motion in conservation form, the temporal discretization is done first and then spatial discretization follows in contrast to the conventional approaches. A predictor-corrector type algorithm has been developed previously by the same author. A new computationally efficient direct algorithm is proposed in this study. A study on convergency and accuracy of the solution is carried out. Numerical examples show that this new algorithm exhibits the same order of accuracy with less computational effort.

• Proceedings of the KAIS Fall Conference
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• 2010.05a
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• pp.257-260
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• 2010

In this paper, we propose the computation reduction methods of LSP(Line spectrum pairs) transformation that is mainly used in CELP vocoders. In order to decrease the computational time in real root method the characteristic of four proposed algorithms is as the following. First, scheme to reduce the LSP transformation time uses mel scale. Developed the second scheme is the control of searching order by the distribution characteristic of LSP parameters. Third, scheme to reduce the LSP transformation time uses voice characteristics. Developed the fourth scheme is the control of searching interval and order by the distribution characteristic of LSP parameters. As a result of searching time, computational amount, transformed LSP parameters, SNR, MOS test, waveform of synthesized speech, spectrogram analysis, searching time is reduced about 37.5%, 46.21%, 46.3%, 51.29% in average, computational amount is reduced about 44.76%, 49.44%, 47.03%, 57.40%. But the transformed LSP parameters of the proposed methods were the same as those of real root method.

• Structural Engineering and Mechanics
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• v.72 no.4
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• pp.525-540
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• 2019

The purpose of the present work was to study the dynamic instability of a three-layered, symmetric sandwich beam subjected to a periodic axial load resting on nonlinear elastic foundation. A higher-order theory was used for analysis of sandwich beams with soft core on elastic foundations. In the higher-order theory, the Reddy's third-order theory was used for the face sheets and quadratic and cubic functions were assumed for transverse and in-plane displacements of the core, respectively. The elastic foundation was modeled as nonlinear's type. The dynamic instability regions and free vibration were investigated for simply supported conditions by Bolotin's method. The results showed that the responses of the dynamic instability of the system were influenced by the excitation frequency, the coefficients of foundation, the core thickness, the dynamic and static load factor. Comparison of the present results with the published results in the literature for the special case confirmed the accuracy of the proposed theory.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.5
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• pp.152-158
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• 1996

A novel resonant pulse control technique which generates high-quality sinusoidal output voltage from a resonant dc link inverter is presented for UPS applicatons. The proposed control technique limits resonant voltae overshoot without any passive or active clamp circuit, resulting in resonant pulses iwth uniform amplitude and high efficiency. The output voltage is controlled by the third order contorller iwth an inner loop of th efilter inductor current and the feedforward controller. Analysis and design of the proposed control technique are illustrated and verified on a 5kVA experimental unit.

• Proceedings of the Korean Society of Crop Science Conference
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• 2000.11a
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• pp.225-226
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• 2000

• 한국정보통신설비학회:학술대회논문집
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• 2003.08a
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• pp.38-39
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• 2003

In this Paper, Laser nonlinearity is analyzed by Rate Equation. Two-tone third-order intermodulation distortions are calculated from Rate Equation. Simulation results and experiment results are compared.

• Advances in concrete construction
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• v.15 no.2
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• pp.137-147
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• 2023

Dynamic analysis of a shear deformable shell is investigated with accounting thickness stretching using Hamilton's principle. Through this method, the total transverse is composed into bending, shearing and stretching portions, in which the third part is responsible for deformation along the transverse direction. After computation of the strain, kinetic and external energies, the governing motion equations are derived using Hamilton's principle. A comparative study is presented before presentation of full numerical results for confirmation of the formulation and methodology. The results are presented with and without thickness stretching to show importance of the proposed theory in comparison with previous theories without thickness stretching.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.42 no.3
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• pp.206-216
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• 2019

The present study identified several antecedents that create perceived resistance to supply chain management (SCM) change. This work particularly emphasizes SCM change, which is notable given its central role in reacting market orientation and varied environmental and managerial conditions. A careful case study on a small and medium sized food production company in South Korea leads to the formulation of our framework including one second-order construct of 'resistance' as well as eight first-order constructs of 'implementing the payment terms', 'balancing of business process', 'fear of responsibility', 'business sustainability transparency', 'past experience of failure', 'competence of work personnel', 'cooperation with third parties' and 'sharing personnel information with partner'. The hypothesized relation of first- and second-order construct was validated using survey sample data collected from 350 respondents who completed their questionnaire instrument. Results from confirmatory factor analysis revealed that nomological validity was established at statistical significance level by identifying six first order constructs of 'implementing the payment terms', 'fear of responsibility', 'business sustainability transparency', 'past experience of failure', a conbined construct of 'competence of work personnel/cooperation with third parties' and 'sharing personnel information with partner'. The findings from our work are expected to provide important insights to the strategy for SCM risk management for small and medium sized company.

• Genomics & Informatics
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• v.10 no.4
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• pp.256-262
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• 2012

Most common complex traits, such as obesity, hypertension, diabetes, and cancers, are known to be associated with multiple genes, environmental factors, and their epistasis. Recently, the development of advanced genotyping technologies has allowed us to perform genome-wide association studies (GWASs). For detecting the effects of multiple genes on complex traits, many approaches have been proposed for GWASs. Multifactor dimensionality reduction (MDR) is one of the powerful and efficient methods for detecting high-order gene-gene ($G{\times}G$) interactions. However, the biological interpretation of $G{\times}G$ interactions identified by MDR analysis is not easy. In order to aid the interpretation of MDR results, we propose a network graph analysis to elucidate the meaning of identified $G{\times}G$ interactions. The proposed network graph analysis consists of three steps. The first step is for performing $G{\times}G$ interaction analysis using MDR analysis. The second step is to draw the network graph using the MDR result. The third step is to provide biological evidence of the identified $G{\times}G$ interaction using external biological databases. The proposed method was applied to Korean Association Resource (KARE) data, containing 8838 individuals with 327,632 single-nucleotide polymorphisms, in order to perform $G{\times}G$ interaction analysis of body mass index (BMI). Our network graph analysis successfully showed that many identified $G{\times}G$ interactions have known biological evidence related to BMI. We expect that our network graph analysis will be helpful to interpret the biological meaning of $G{\times}G$ interactions.