• Journal of the Korea Furniture Society
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• v.20 no.4
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• pp.374-387
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• 2009

Gerrit Rietveld who is Dutch architect and furniture designer had explored the plastic abstractness based on the universality of De Stijl principle. He had tried to expand the boundary of furniture design bound to traditional form and decorative aesthetics. Beginning of 20th century, he opened the new aesthetic realm of pure and abstract value for furniture design for the first time. Through this research, the results can be summarized as follows. The characteristics of his deign are abstractness, spatial consideration and tectonic construction. The abstractness is attained by simplifying constructional material into geometrical forms such as straight line, rectangle and square. And he adopted unconventional way of construction in order to increase this abstractness. The space included in his furniture can be expressed in the new technology of joint, the visual transparency using linear material, and the destruction of corners. All these aspects harmoniously helped the feeling of architectural space of flow. Through the exposed frame of furniture, Rietveld emphasized on the tectonic construction by methodological treatment such as piling-up or overlapping material. The characteristics of Gerrit Rietveld's design are abstract, spatial and tectonic. These aesthetical tendencies could be understood as a junction between De Stijl's principles and modern architecture's spatial preferences-flow and extension of space-.

• International Journal of Automotive Technology
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• v.7 no.7
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• pp.853-858
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• 2006

The method of die-face design based on the CAE platform for automobile panels can fast modify the die addendum. In contrast with the process of the die-face design based on the CAD platform, there are some special steps for the die-face design based on the CAE platform. The most obvious difference is that the auto-body part contour needs smoothing arlier than the design of addendum surfaces does. It is helpful to improve the design quality of addendum surface. In spite of extensive researches on the smoothing technique, here is still dearth of the published solutions about smoothing the part contour with additional surface. This paper attempts to analyze the difficulties and provides practical solutions. Main results include the algorithm to calculate the segments needing to be smoothed on boundary, the strategy to create the smoothing curve and the procedure of surface generation. The relevant function modules for parametric design are developed. A few examples and suggestions for future work conclude the paper.

• Journal of the Korea Computer Graphics Society
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• v.4 no.1
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• pp.55-66
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• 1998

This paper presents a simple method for relieving the ambiguity problems within the sub-voxel based surface-fitting approach for the surface construction. ECB algorithm is proposed to avoid the ambiguity problem which is the root of the holes within the resulting polygon based approximation. The basic idea of our disambiguation strategy is the use of a set of predefined modeling primitives (we call SMP) which guarantees the topological consistency of resulted surface polygons. 20 SMPs are derived from the extension of the concept of the elementary modeling primitives in the CB algorithm [3], and fit one to five faces of them to the iso-surface crossing a cell with no further processing. A look-up table which has a surface triangle list is pre-calculated using these 20 SMPs. All of surface triangles in the table are from the faces of SMPs and are stored in the form of edge list on which vertices of each surface triangle are located. The resulted polygon based approximation is unique at every threshold value and its validity is guaranteed without considering the complicated problems such as average of density and postprocessing. ECB algorithm could be free from the need for the time consuming post-processing, which eliminates holes by revisiting every boundary cell. Through three experiments of surface construction from volume data, its capability of hole avoidance is showed.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.6
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• pp.713-719
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• 2004

This paper presents an interval type-2 fuzzy C-spherical shells (FCSS) algorithm that is an extension of the type-1 FCSS algorithm proposed in (1). In our proposed method, the membership values for each pattern vector are extended as interval type-2 fuzzy memberships by assigning uncertainty to the type-1 memberships. By doing so, the cluster boundary obtained by the interval type-2 FCSS can be found to be more desirable than that of type-1 FCSS in the presence of noise. Experimental results are given to show the effectiveness of our method.

• Journal of the Korean Society for Library and Information Science
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• v.44 no.4
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• pp.373-393
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• 2010

In the current information environment around the library community, metadata is recognized as a sophisticated and powerful tool that can manage and represent information resources. However, with the discreet use of the concepts of metadata and metadata standard, there is no clear boundary that differentiates metadata standard from simple resource description and traditional bibliographic structure, leading to confusion as to what a metadata and metadata standard is. To consider these issues, this research discussed what metadata and metadata standards are based previous definitions of metadata. Based on those definitions, the fundamental concept of metadata is reestablished to be properly used in the library community.

• Structural Engineering and Mechanics
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• v.16 no.2
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• pp.195-217
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• 2003

This paper, which is an extension of a previous work by Viola et al. (2002), deals with the dynamic stability of beams under a triangularly distributed sub-tangential forces when the effect of an elastically restrained end is taken into account. The sub-tangential forces can be realised by a combination of axial and tangential follower forces, that are conservative and non-conservative forces, respectively. The studied beams become unstable in the form of either flutter or divergence, depending on the degree of non-conservativeness of the distributed sub-tangential forces and the stiffness of the elastically restrained end. A non-conservative parameter ${\alpha}$ is introduced to provide all possible combinations of these forces. Problems of this kind are usually, at least in the first approximation, reduced to the analysis of beams according to the Bernoulli-Euler theory if shear deformability and rotational inertia are negligible. The equation governing the system may be derived from the extended form of Hamilton's principle. The stability maps will be obtained from the eigenvalue analysis in order to define the divergence and flutter domain. The passage from divergence to flutter is associated with a noticeable lowering of the critical load. A number of particular cases can be immediately recovered.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.04a
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• pp.537-544
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• 2003

This paper deals with stress corrosion cracking behavior of high strength steel exposed to marine environments. The objective is to determine the time to failure as a function of hydrogen concentration and tensile stress in the wires. A crack growth curve is modeled using finite element method (FEM) program. The coupled hydrogen diffusion-stress analyses of SCC were programmed separately. The first part is calculating stress and stress intensity /sup 1)/factor of a cylindrical shell, prestressing tendon or suspension bridge wires, from the initiation of cracks to rupture. Virtual crack extension method, contour integral method, and crack tip elements are used for the calculation of stresses in front of the crack tip. Comparisons of the result show a good agreement with the analytical equations and wire tests. The second part of the study deals with the programming of hydrogen diffusion, affected by hydrostatic stress, calculated at the location of boundary of plastic area around the crack tip. The results of paper can be used in the design and management of prestressed structures, cable stayed and suspension bridges. Time dependent correlated parallel reliabilities of a cable, composed of 36 wires, were evaluated by the consideration of the deterioration of stress corrosion cracking.

• Journal of the Korean Ceramic Society
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• v.22 no.5
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• pp.76-84
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• 1985

Mechanical property enhancing mechanisms of $Al_2O_3-ZrO_2$ two phase ceramic composites were studied for several compositions of different $ZrO_2$/$Al_2O_3$ ratio. Microstructural analysis of $Al_2O_3-ZrO_3$(pure) composites indicated that pre-existing microcrack due to larger $ZrO_2$ particle at grain boundary extended along alumina grain boundaries within process zone. Microcracks also nucleated when very small $ZrO_2$ particles at the grain boundaries transformed to monoclinic phase at near of main crack tip. These types of microcracks could contribute to the toughening achieved by creating additional crack surface area during crack propagation. Microstructural analyses also showed that the average grain size and abnormal grain size of $Al_2O_3$ were decreased with increasing $ZrO_2$ vol% in $Al_2O_3$ matrix. As a result it could be concluded as follows In TEX>$Al_2O_3-ZrO_3$(pure) system 1. Microcrack nucleation (stress-induced microcracking) and extension was effective mechanism for absorpiton of fracture energy 2, More narrow distribution and smaller grain size of $Al_2O_3$ due to $ZrO_2$particles mainly contributed to main-tatin the strength and hardness.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.6 s.237
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• pp.860-875
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• 2005

A new meshfree method for the analysis of elasto-plastic deformations is presented. The method is based on the proposed first-order least-squares formulation, to which the moving least-squares approximation is applied. The least-squares formulation for the classical elasto-plasticity and its extension to an incrementally objective formulation for finite deformations are proposed. In the formulation, the equilibrium equation and flow rule are enforced in least-squares sense, while the hardening law and loading/unloading condition are enforced exactly at each integration point. The closest point projection method for the integration of rate-form constitutive equation is inherently involved in the formulation, and thus the radial-return mapping algorithm is not performed explicitly. Also the penalty schemes for the enforcement of the boundary and frictional contact conditions are devised. The main benefit of the proposed method is that any structure of cells is not used during the whole process of analysis. Through some numerical examples of metal forming processes, the validity and effectiveness of the method are presented.

• Journal of the korean society of oceanography
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• v.37 no.3
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• pp.134-143
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• 2002

Using OGCM results, we have shown that the ring-like cold baroclinic eddies associated with cyclonic circulation are shed from late summer to early fall near the Izu-Ogasawara Ridge from the Kuroshio Extension owing to baroclinic instability. On the other hand, warm baroclinic eddies are generated by the intensified western boundary current associated with the warm anomaly accumulated near the Ridge in winter, which corresponds to the basin-wide barotropic intensification of the wind-driven gyre in winter. We are successful in reproducing the behavior of those meso-scale eddies using a simple two-layer primitive equation model driven by seasonal winds associated with the positive curl. Those eddies carry barotropic seasonal signals originated in the Pacific Basin quite slowly west of the ridge; this process introduces a phase lag in the timing of the seasonal maximum transport in the Philippine Basin west of the ridge. It Is demonstrated that the existence of bottom topography, baroclinicity, and nonlinearity due to advection are three necessary elements for the generation of these eddies south of Japan.