• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1997.03a
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• pp.244-248
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• 1997

In the rolling process, keeping the accuracy of the slab width is a very important problem. So the edge rolling is used with the plate rolling. But in the edge rolling, a local contraction of width, called "width necking", occurs in the top and tail portion of a slab and becomes the cause of crop loss. In this investigation, the three dimensional deformation behavior in the edge-plate rolling is simulated by rigid plastic FEM(PROLL). And the influence of the rolling condition on "width necking" and the accuracy of width is examined.

• Transactions of Materials Processing
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• v.6 no.3
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• pp.203-212
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• 1997

In this research, to obtain the optimal die width of CV die(conventional die), which replaces FM die in free forging of large scale rotor using the flat die, the model material experiments and theoretical analysis using three dimensional FEM are performed. The FM die, which was designed to remove Mannesmann's effect at the central part of the ingot, has very bad workabiltity in real field, therefore on the empirical base they use the CV die of wide width in actual working field. In this study, the excellency of CV die is proved quantitively, and the optimal die width of CV die is determined through the model material experiments and theoretical analysis using FEM in the point of effective strain, stresses, and load.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1995.10a
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• pp.150-156
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• 1995

In the finite element analysis of metal forming processes, the updated Lagrangian approach has been widely and effectively used to simulate the non-steady state problems. However some difficulties have arisen from abrupt flow change as in extrusion through square dies. In the present work, a ALE(arbitrary Lagrangian-Eulerian) finite element formulation for deformation analysis are presented for rigid viscoplastic materials. The developed finite element program is applied to the analysis of square die extrusion of a square section. The computational results are compared with those from the updated Lagrangian finite element analysis.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.357-362
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• 2000

This Paper presents dynamic analysis of underground R/C Subway Structure, subjected to seismic actions. Earthquakes brought serious damage to RC subway Structure. Foe studying the collapse mechanism of underground RC Subway, seismic of a subway station is simulated in using FEM program ASP2000 of two-dimension based on the path dependent RC elastic model, soil foundation and interfacial models. The shear failure of intermediate vertical columns is founds to be the major cause of the structural collapse. According to FEM simulation of the failure mechanism, it is considered that the RC column would lose axial load carrying capacity after the occurrence of the localized diagonal shear cracks , and sudden failure of the outer frame would be followed. Specially, the shear stress in the middle slab reaches maximum shear capacity. So, the Structure would fail in the middle slab as a result of erasing the vertical ground motion computation.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.884-889
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• 2003

Based on the reinterpretation of the well-known relationship between shear and the rate of change of bending moment in a reinforced concrete beam subject to combined shear and moment loads, the shortcomings of present truss models are discussed. The core of the theory is that a new perspective on the shear strength can be gained by viewing the internal stress filed in terms of the superposition of two base components of shear resistance; arch action and beam action. The arch action can be designed using the simple truss having curved compression chord, while the beam action between the two chords can be modeled using a parallel chord truss with MCFT or RA-STM. The compatibility of deformation associated to the two action is taken into account by employing a characteristic factor a. The new model was examined by the Stuttgart beam shear tests, and the results show that the present approach provides good estimates of stirrup contribution and concrete contributions.

• The Journal of the Korean dental association
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• v.44 no.6 s.445
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• pp.359-366
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• 2006

• Proceedings of the IEEK Conference
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• 2003.11b
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• pp.231-234
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• 2003

This paper designs and implements fault-tolerant server of meta server for shared filesystem (SANfs) in SAN environment. SANfs is the filesystem that many clients can share data in Network-attached storage in SAN environment and meta server is the server that processes file operation in SANfs. The focus of this paper is the implementation of fault-tolerant server of meta server in SANfs. In the event of a meta server, meta server failovers to a fault-tolerant server where its processing continues seamlessly. If meta server doesn't restore, fault-tolerant server searches reliable client and makes another fault-tolerant server and work as meta server. Heartbeat monitors meta server and shadow server and controls them.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.1
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• pp.114-121
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• 1998

In this paper, we introudce the notion of the smoothly perfect 8-conntected (SP8C) contour and describe a coding technique for the SP8C contours. Based on the simplificationusing the majority filter proposed by Gu, SP8C contours are restricted on the contour lattice from the segmented image. By noting thating SP8C contours are restricted to travel in only 3 different directions along the contours, we attempt to encode the SP8C contours using the following two techniques. The one is the neighbouring direction segmentcoding, while the other is to employ the notion of the entropy endoding. Computer simulations reveal that the contours can be efficiently encoded by the two technique.

• Journal of the Korean Institute of Telematics and Electronics
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• v.14 no.4
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• pp.22-31
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• 1977

A general equation by which the Hessian matrix of an error function can be determined directly, has been derived. It was verified to be useful in optimization processes that include the Hessian matrix. A few design examples had shown that this method had accelerated the processes of finding the minimums. The advantage of this technique is the possibility of optimizing functions that composed of both the phases and magnitudes.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2004.11a
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• pp.381-385
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• 2004

A goal of this research is to propose and testify the remodeling possibility from deteriorated stock apartment housing, to three generation family living in a dwelling unit for low incomes. An apartment housing which is introduced from 1970s, is accumulated over 55% of the stock housing in Korea, many of them are confront with a rebuilding in a short usage of twenty years below. They were built in a small one, and it testified from two to one conversion in this article that can be applicated in a 10, 13, 14, I5, and 16 pyung, the remodeling size became from 20 to 36 pyung. In this article, we can see a reform model in possible for three generation family living in the small apartment house.