• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.530-534
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• 2007

Flow visualization is one of visualization techniques and it means a visual expression of vector data using 2D or 3D graphics. It aims for human to easily understand a special feature of the vector data. Flow visualization can be classified into various criterions such as visualization technique, data dimension, type of the flow, and so on. Visualization technique can be categorized into direct method, integration method and derived data based method. Data dimension can be divided into 2D, 2.5D and 3D. Type of flow data may be classified into steady and unsteady. In this paper, various LIC based flow visualization methods will be introduced which is one of representative integration based techniques. Those methods will be categorized with more detailed criterions such as dimension and type of flows.

• Journal of Advanced Navigation Technology
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• v.16 no.4
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• pp.697-702
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• 2012

With an elevator supply and demand increases, It has been enlarged various requirements for the safety of the elevator. Elevator safety requirements can be the ability to respond to emergencies quickly. Recently, QR code was attached to all elevator for the elevator safety and it is established by law for the Elevator rescue work. And also the elevator system is seeking to utilize more secure elevator with mandatory installation of CCTV and direct call devices. However, CCTV and direct call service is operating on an individual method and it has not been proposed integrated model. In this paper, we propose the safety elevator integration model with CCTV, direct call service and remote control based on smart phone. Using the proposed model, we can be improved the efficiency of maintenance and ability of prompt action in the event of a disaster.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.2
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• pp.380-390
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• 1998

In the present work a finite element formulation using dynamic explicit time integration scheme is used for numerical analysis of auto-body panel stamping processes. The lumping scheme is employed for the diagonal mass matrix and linearizing dynamic formulation. A contact scheme is developed by combining the skew boundary condition and direct trial-and-error method. In this work, for economic analysis the faster punch velocity and the mass scaling method are introduced. To investigate the effects of punch velocity and mass scaling, the various values of punch velocity and the various mass scalings are used for numerical analysis. Computations are carried out for analysis of complicated auto-body panel stamping processes such as forming of an oil pan and a fuel tank.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2001.11a
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• pp.57-61
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• 2001

In a main propulsion system of naval ship, DRME(Double Resilient Mounted Engine) is mostly adopted to ensure vibration isolation and shock resistance against underwater explosion weapon attack. In this paper, an analysis program for vibration and shock evaluation of DRME is presented. DRME is modelled as multi-rigid bodies with nonlinear mounts, and direct time integration method is introduced for shock analysis. The computed results are compared with those of foreign ones. Navy's proposed specifications are well satisfied with this program. This analysis program serves for the development of domestic DRME technology of naval ship.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.12
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• pp.3007-3019
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• 1993

For the same configuration, the stiffness of 6-node two dimensional isoparametric is stiffer than that of 8-node two dimensional isoparametric element. This phenomenon may be called 'Relative Stiffness Stiffening Phenomenon.' In this paper, the relative stiffness stiffening phenomenon was studied, and could be corrected by modifying the position of Gauss integral points used in the numerical integration of the stiffness matrix. For the same deformation (bending) energy of 6-node and 8-node two dimensional isoparametric elements, Gauss integral points of 6-node element have to move closer, in comparison with those of 8-node element, in the case of numerical integration along the thickness direction.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.3
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• pp.15-20
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• 2015

After the US government declared 3D printing technology a next-generation manufacturing technology, there have been many practical studies conducted to expand 3D printing technology to manufacturing technologies, called AMERICA MAKES. In particular, the Keck Center, located at the University of Texas at El Paso, has studied techniques for easily combing the 3D stacking process with space mobility and expanded these techniques to simultaneous staking techniques for multiple materials. Additionally, it developed convergence manufacturing techniques, such as direct inking techniques, in order to produce a module structure that combines electronic circuits and components, such as CUBESET. However, in these studies, it is impossible to develop a unified system using traditional independent through simple sequencing connections. This is because there are many problems in the integration between the stacking modeling of 3D printers and post-machining, such as thermal deformations, the precision accuracy of 3D printers, and independently driven coordinate problems among process systems. Therefore, in this paper, the integration method is suggested, which combines these 3D printers and subsequent machining process systems through an Internet-based cloud. Additionally, the sequential integrated system of a 3D printer, an NC milling machine, machine vision, and direct inking are realized.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.33 no.1
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• pp.38-45
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• 1997

The steady drift forces on a barge in waves are investigated. The steady drift forces due to a near-field method which is based on direct integration of the pressure acting on the submerged surface of barge are compared with those due to far-field method which is based on the theory of momentum conservation. Numerical results of the linear motions are compared with the experimental and numercal ones which was submitted in the literature. A convergence of the steady drift forces according to the increase of the number of panels which represent the submerged surface are discussed.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.10a
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• pp.93-96
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• 2001

Design sensitivity is calculated in the sheet metal forming process with an elasto-plastic finite element analysis and a direct differentiation method The sensitivity analysis is concerned with the time integration the constitutive relation considering planar anisotropy, shell elements and the contact scheme. The present result is compared with the result obtained with the finite difference approach in deep drawing processes. The obtained sensitivity information is applied to the simple optimization process for the sheet metal forming process.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2001.05a
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• pp.52-57
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• 2001

Laminar two-dimensional time-dependent flow past a circular cylinder is numerically investigated using direct numerical simulation for the low Reynolds number (Re=164∼280). The higher-order finite difference scheme is employed for the spatial distributions along with the second order Adams-Bashforth and the first order backward-Euler time integration. The convection term is applied by the 7th order up wind scheme and the pressure and viscosity terms are applied by the 4th order central difference. The grid system makes use of the regular grid system and it is generated by an equation. The calculated results of drag coefficients, lift coefficients, pressure distributions, and vorticity contours and other information are compared with experimental and numerical ones. These results obtained by the present DNS show good agreement with the previous studies.

• Structural Engineering and Mechanics
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• v.38 no.2
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• pp.211-229
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• 2011

In this paper, we present a new explicit procedure using periodic cubic B-spline interpolation polynomials to solve linear and nonlinear dynamic equation of motion governing single degree of freedom (SDOF) systems. In the proposed approach, a straightforward formulation was derived from the approximation of displacement with B-spline basis in a fluent manner. In this way, there is no need to use a special pre-starting procedure to commence solving the problem. Actually, this method lies in the case of conditionally stable methods. A simple step-by-step algorithm is implemented and presented to calculate dynamic response of SDOF systems. The validity and effectiveness of the proposed method is demonstrated with four examples. The results were compared with those from the numerical methods such as Duhamel integration, Linear Acceleration and also Exact method. The comparison shows that the proposed method is a fast and simple procedure with trivial computational effort and acceptable accuracy exactly like the Linear Acceleration method. But its power point is that its time consumption is notably less than the Linear Acceleration method especially in the nonlinear analysis.