• Journal of Mechanical Science and Technology
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• v.20 no.12
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• pp.2034-2042
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• 2006

In this study, a complete 3D surface reconstruction method is proposed based on the concept that the vertices, of surface model can be completely matched to the unstructured point cloud. In order to generate the initial mesh model from the point cloud, the mesh subdivision of bounding box and shrink-wrapping algorithm are introduced. The control mesh model for well representing the topology of point cloud is derived from the initial mesh model by using the mesh simplification technique based on the original QEM algorithm, and the parametric surface model for approximately representing the geometry of point cloud is derived by applying the local subdivision surface fitting scheme on the control mesh model. And, to reconstruct the complete matching surface model, the insertion of isolated points on the parametric surface model and the mesh optimization are carried out. Especially, the fast 3D surface reconstruction is realized by introducing the voxel-based nearest-point search algorithm, and the simulation results reveal the availability of the proposed surface reconstruction method.

• Journal of Korean Library and Information Science Society
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• v.38 no.3
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• pp.161-181
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• 2007

This study examined the changes, development and characteristics of the cartographic materials field in LCC as a suggestion of an ideal classification scheme which is necessary for classily the cartographic materials in libraries. The main purpose this study is to suggest how to apply the examination results to the related subject field in KDC focused on the integration and subdivision of area table and developing subject subdivision table.

• Journal of the Korean Society for Library and Information Science
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• v.22
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• pp.259-304
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• 1992

This paper examines 'Religion Class' in the scheme of the DDC. The major findings of the study are summerized as follows. 1. The first edition of DDC was published in 1876 in order to classify Amherst College Library collections. In spite of the continuous study and revision of the experts, the frameworks of the DDC systems are still kept unchanged. Only their subdivisions, reflecting those developments in the academic world, are developed and detailed more sophisticatedly. 2. The division of 200 does not function as generalities for all class of religion. Therefore, it is necessary to amend the division of 200 to serve generalities for all the religions of the world. 3. Standard subdivision for the christian religion and for the non-christian religion is different. So, the mnemonic nature has become weakened due to the dual standard subdivisions and the classification number becomes much longer and complicated. Therefore, one standard subdivision for all religions of the world is required. 4. Religion science was organized in late 19 C and developed continuously, but the DDC does not accomodate the religion science as a science. Accodingly, the DDC should be revised recognize religion science as a science not the christian science. 5. The deployment of classification scheme in Dewey's 200 is severely biased. That is to say, 9 division were assigned for christian religion, whereas only 1 division was assigned for non-christian religion. Therefore, an adjustment should be made to allocate subdivisions equally to all religions of the world. 6. General classification order of religion is prehistoric, primitive, ancient, modem and world religion in religion science. But, DDC does not accept this general classification order of religion, sticking to the biased expansion towards christianity. Therefore, DDC must adopt the general classification order of religion in the religion science. 7. Lastly, because of the limitation of decimal notation in DC, DDC does not accomodate new subject equally and classification number becomes longer. Therefore, centesimal expansion is proposed in order to make the classification number short, to enlarge its capacity of inclusion of new subject and to maintain consistency in the scheme.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.4 s.235
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• pp.570-577
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• 2005

In this study a complete 3D surface reconstruction method is proposed based on the concept that the vertices of surface model can be completely matched to the unstructured point cloud. In order to generate the initial mesh model from the point cloud, the mesh subdivision of bounding box and shrink-wrapping algorithm are introduced. The control mesh model for well representing the topology of point cloud is derived from the initial mesh model by using the mesh simplification technique based on the original QEM algorithm, and the parametric surface model for approximately representing the geometry of point cloud is derived by applying the local subdivision surface fitting scheme on the control mesh model. And, to reconstruct the complete matching surface model, the insertion of isolated points on the parametric surface model and the mesh optimization are carried out Especially, the fast 3D surface reconstruction is realized by introducing the voxel-based nearest-point search algorithm, and the simulation results reveal the availability of the proposed surface reconstruction method.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.38 no.1
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• pp.45-52
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• 2001

The proximal isovelocity surface area (PISA) method is an effective way of measuring the regurgitant blood flow rate in the mitral valve. This method defines the modelling required to describe the geometry of the isotach of the PISA. In the normal PISA flow model, the flow rate is calculated assuming that the surface of the isotach is either hemispherical or non-hemispherical numerically. However, this paper evaluated the estimate flow rate using a direct surface subdivision flow model based on the height field after isotach extraction using a region-based scheme. To validate the proposed method, the various PISA flow models were compared using pusatile color Doppler images with flow rates ranging from $30\;cm^3/sec\;to\;60\;cm^3/sec$ flow rate. Whereas the hemispherical flow model had a mean value of $29\;cm^3/sec$ and underestimated the measured flow rate by 35%, the proposed model and non-hemispherical model produced a c;ame mean value of $45\;cm^3/sec$, moreover, both flow models produced a similar pulsatile flow rate.

• Nuclear Engineering and Technology
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• v.36 no.4
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• pp.285-294
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• 2004

Pressure wave propagation in the discharge piping with a sparger submerged in a water pool, following the opening of a safety relief valve, is analyzed. To predict the pressure transient behavior, a RELAP5/MOD3 code is used. The applicability of the RELAP5 code and the adequacy of the present modeling scheme are confirmed by simulating the applicable experiment on a water hammer with voiding. As a base case, the modeling scheme was used to calculate the wave propagation inside a vertical pipe with sparger holes and submerged within a water pool. In addition, the effects on wave propagation of geometric factors, such as the loss coefficient, the pipe configuration, and the subdivision of sparger pipe, are investigated. The effects of inflow conditions, such as water slug inflow and the slow opening of a safety relief valve are also examined.

• Korean Journal of Computational Design and Engineering
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• v.15 no.1
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• pp.24-32
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• 2010

This paper introduces a B-spline based branch & bound algorithm for global optimization. The branch & bound is a well-known algorithm paradigm for global optimization, of which key components are the subdivision scheme and the bound calculation scheme. For this, we consider the B-spline hypervolume to approximate an objective function defined in a design space. This model enables us to subdivide the design space, and to compute the upper & lower bound of each subspace where the bound calculation is based on the LHS sampling points. We also describe a search tree to represent the searching process for optimal solution, and explain iteration steps and some conditions necessary to carry out the algorithm. Finally, the performance of the proposed algorithm is examined on some test problems which would cover most difficulties faced in global optimization area. It shows that the proposed algorithm is complete algorithm not using heuristics, provides an approximate global solution within prescribed tolerances, and has the good possibility for large scale NP-hard optimization.

• Journal of KIISE:Computer Systems and Theory
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• v.29 no.6
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• pp.307-317
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• 2002

In this paper we propose a new mesh reconstruction scheme that produces a displaced subdivision surface directly from unorganized points. The displaced subdivision surface is a new mesh representation that defines a detailed mesh with a displacement map over a smooth domain surface, but original displaced subdivision surface algorithm needs an explicit polygonal mesh since it is not a mesh reconstruction algorithm but a mesh conversion (remeshing) algorithm. The main idea of our approach is that we sample surface detail from unorganized points without any topological information. For this, we predict a virtual triangular face from unorganized points for each sampling ray from a parameteric domain surface. Direct displaced subdivision surface reconstruction from unorganized points has much importance since the output of this algorithm has several important properties: It has compact mesh representation since most vertices can be represented by only a scalar value. Underlying structure of it is piecewise regular so it ran be easily transformed into a multiresolution mesh. Smoothness after mesh deformation is automatically preserved. We avoid time-consuming global energy optimization by employing the input data dependant mesh smoothing, so we can get a good quality displaced subdivision surface quickly.

• Journal of Korean Library and Information Science Society
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• v.30 no.3
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• pp.53-96
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• 1999

This study intends to : 1) confirm the possibility to transform the enumerated scheme into the faceted scheme, 2) review general theories on facet structure employed in DDC of the enumerated scheme, 3) analyze the facet structure of life science and literature in DDC, and 4) comparison of the facet structure of life science and literature in DDC and CC. This study suggests following conclusions. 1) CC follows throughly the classification principles by Ranganathan, but all classification theories are not property applied to DDC yet. 2) Because DDC does not have any formula to classify the compound subject, but has to follow the compounding methods presented in each subject, its facet structure is too complicated. 3) DDC has transformed the entire system into the facet structure through its revision. Expecially the life science transformed into the facet structure employed the facet indicators and applies them to all the systems in life science. But the notations have sometimes twofold meanings, and no ability to differentiate the meanings in the same notation,. When DDC follows the classification method by facet, the number of items for classification so limited that it is difficult to array the subdivision and that length of notation becomes longer and longer.

• Journal of Korean Library and Information Science Society
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• v.32 no.4
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• pp.147-170
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• 2001

This study intends to 1)conform the possibility to transform the enumerated scheme into the faceted scheme, 2)review general theories on facet structure employed in DDC 780, and 3) analyze the facet structure of music. Findings are 1) The facet structure of DDC synthesize the standard subdivisions or specific facet indicators with basic facet. 2) facet indicator 0 is in use to indicate standard subdivision or general principle of music. and facet indicator 1 to general principles and musical forms. DDC has transformed the entire system into the facet structure through its revisions. Especially the music transformed into the facet structure employes the facet indicators and applies them to all the systems in music. But the notation have sometimes twofold meanings, and no ability to differentiate the meanings in the same notation.