• Journal of Institute of Control, Robotics and Systems
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• v.18 no.3
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• pp.175-180
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• 2012

A nonlinear navigation filter for biomimetic robot using analytic approximation of mean and covariance of state variable is proposed. The approximations are performed at the time update step in the filter structure. The mean is approximated to the 3rd order of Taylor's series expansion of true mean and the covariance is approximated to the 3rd order either. The famous EKF is a nonlinear filtering method approximating the mean to 1st order and the covariance to the 3rd order. The UKF approximate them to the higher orders by numerical method. The proposed method derived a analytical approximation of them for navigation system and therefore don't need so called sigma point transformation in UKF. The simulation results show that the proposed method can be a good alternative of UKF in the systems which require less computational burden.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2002.04a
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• pp.369-376
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• 2002

The stochastic analysis of semi-infinite domain is presented using the weighted integral method, which is improved to include the higher order terms in expanding the displacement vector. To improve the weighted integral method, the Lagrangian remainder is taken into account in the expansion of the status variable with respect to the mean value of the random variables. In the resulting formulae only the 'proportionality coefficients' are introduced in the resulting equation, therefore no additional computation time and memory requirement is needed. The equations are applied in analyzing the semi-infinite domain. The results obtained by the improved weighted integral method are reasonable and are in good agreement with those of the Monte Carlo simulation. To model the semi-infinite domain, the Bettess's infinite element is adopted, where the theoretical decomposition of the strain-displacement matrix to calculate the deviatoric stiffness of the semi-infinite domains is introduced. The calculated value of mean and the covariance of the displacement are revealed to be larger than those given by the finite domain assumptions which is thought to be rational and should be considered in the design of structures on semi-infinite domains.

• Proceedings of the KIPE Conference
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• 2017.07a
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• pp.403-404
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• 2017

In an electric vehicle driving system, the regeneration power charging the battery with electricity is applied as the driver controls the brake. This paper is proposed a torque compensation algorithm that can regenerate due to extend regeneration area at the low speed of EV system. In order to verify the proposed method, PSIM simulation is performed and it is confirmed that regeneration occurred the proposed method is regenerated at low speed by comparing the existing method with the proposed method.

• Journal of Advanced Navigation Technology
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• v.14 no.6
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• pp.900-908
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• 2010

Recently, OOM(Object-Oriented Method) access method which begins to apply to software development is emphasizing development cost and time reduction through independent software reuse. But because of planning to the exclusion of the lack of knowledge and expansion or performance for development technology many problems are coming out. Therefore, this thesis suggests Effective Object-Oriented Modeling methods considering the plan for higher productivity enhancement of software in the software development life cycle. Effective Object-Oriented Modeling method includes, methods, Use Case modeling methods, Analysis Modeling methods, Design Modeling methods and others.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.465-474
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• 2008

This research presented an extraction method of a logical database to create a design form of stream-nose. The practical use of logical database is important for the expansion of thinking area with investigation of Form to create a stream nose. Firstly, We presented apply course with the method to draw the image database as a first step of a stream-nose design. secondly, extraction method of a character-line applied the image-layered technique was an objectified. Such course is for establishing a design process to create the original form of the stream nose.

• Structural Engineering and Mechanics
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• v.69 no.1
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• pp.69-75
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• 2019

The plates made of two materials joined to each other having the different coefficient of thermal expansions are frequently encountered in the industrial applications. The stress analysis of these members under the effect of high-temperature variation has great importance in design. In this study, the stress analysis of the experimental model developed for the problem considered here was performed by the method of photothermoelasticity. The thermal strains were formed by the mechanical way and these were fixed by the strain freezing method. For the stress measurements, the method of slicing is applied which provides three-dimensional stress analysis. The analytical solution in the literature was compared with the related stress distribution obtained from the model. Moreover, the axisymmetric finite element model developed for the problem was solved by ABAQUS and the results obtained here compared with those of the experimental model and the analytical solution. As a result of this study, this experimental method and numerical model can be used for these type of thermal stress problems which have not been comprehensively analyzed yet.

• Journal of applied mathematics & informatics
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• v.39 no.5_6
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• pp.655-676
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• 2021

A parameter uniform numerical scheme is proposed for solving singularly perturbed parabolic partial differential-difference convection-diffusion equations with a small delay and advance parameters in reaction terms and spatial variable. Taylor's series expansion is applied to approximate problems with the delay and advance terms. The resulting singularly perturbed parabolic convection-diffusion equation is solved by utilizing the implicit Euler method for the temporal discretization and finite difference method for the spatial discretization on a uniform mesh. The proposed numerical scheme is shown to be an ε-uniformly convergent accurate of the first order in time and second-order in space directions. The efficiency of the scheme is proved by some numerical experiments and by comparing the results with other results. It has been found that the proposed numerical scheme gives a more accurate approximate solution than some available numerical methods in the literature.

• Journal of the Korean Society of Visualization
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• v.18 no.3
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• pp.35-41
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• 2020

We conduct numerical simulations of the interaction of a deformable structure with two-phase compressible flow. The finite volume method (FVM) is used to simulate fluid phenomena including a shock wave, a gas bubble, and the deformation of free surface. The deformation of a floating structure is computed with the finite element method (FEM). The compressible two-phase volume of fluid (VOF) method is used for the generation and development of a cavitation bubble, and the immersed boundary method (IBM) is used to impose the effect of the structure on the fluid domain. The result of the simulation shows the generation of a shock wave, and the expansion of the bubble. Also, the deformation of the structure due to the hydrodynamic loading by the explosion is identified.

• International Journal of Internet, Broadcasting and Communication
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• v.16 no.3
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• pp.170-183
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• 2024

In producing anamorphic 3D advertisement projects, it is necessary to apply the principles of illusion art to distort the images output to the screen (Image Distortion) so that their display aligns with our visual perception in a real three-dimensional environment. We focuse on the methods of image distortion in the creation of content for anamorphic 3D advertisement screens in this thesis. We propose using Unity 3D's real-time rendering instead of the offline rendering method of compositing method, and employing UV grid mapping to replace the manual correction in Adobe After Effects(AE). The significance of this paper lies in simplifying the image distortion processing workflow in anamorphic 3D projects and optimizing the image distortion creation methods used in compositing method. In outdoor anamorphic 3D advertisement projects, the proposed image distortion creation method demonstrates significant advantages in terms of production time, process simplification, flexibility, and expansion possibilities. Our research provides new perspectives and methods for the creation of anamorphic 3D content, offering theoretical and methodological references for professionals working on similar contents.

• Nuclear Engineering and Technology
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• v.52 no.11
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• pp.2422-2430
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• 2020

In order to improve calculational efficiency of the CAPP code in the analysis of the hexagonal reactor core, we have tried to implement a refined AFEN method with transverse gradient basis functions and interface flux moments in the hexagonal geometry. The numerical scheme for the refined AFEN method adopted here is the response matrix method that uses the interface partial currents as nodal unknowns instead of the interface fluxes used in the original AFEN method. Since the response matrix method is single-node based, it has good properties such as good calculational efficiency and parallel computing affinity. Because a refined AFEN method equivalent nonlinear FDM response matrix method tried first could not provide a numerically stable solution, a direct formulation of the refined AFEN response matrix were developed. To show the numerical performance of this response matrix method against the original AFEN method, the numerical error analyses were performed for several benchmark problems including the VVER-440 LWR benchmark problem and the MHTGR-350 HTGR benchmark problem. The results showed a more than three times speedup in computing time for the LWR and HTGR benchmark problems due to good convergence and excellent calculational efficiency of the refined AFEN response matrix method.