• Journal of Conservation Science
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• v.35 no.5
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• pp.453-469
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• 2019

The celadon jar with inscription of 'the Fourth Sunhwa Year' is an important chronology that shows the conditions of production of the early celadon due to the inscription on the bottom including its purpose, application, and the producer. This celadon jar has been restored several times in the past. However, concerns over the structural stability, such as the separation and level differences in the joined cracks, have risen because of the aging of the repair materials, which were subjected to various environmental changes over a long time. By examining the conditions of preservation, the major damage was identified as the '入' shaped crack on the front, the 'V' shaped restored part and the crack on its left side, and the 'J' shaped crack on the back side. In the past, the cracks were found to be joined using a refined lacquer containing camphor, drying oil, rosin, etc. mixed with soil powder. The joint line was repainted with the refined lacquer and covered with gold powder. The missing parts were restored with gypsum and colored with acrylic color. After that, the repair materials were aged and emergency treatment was performed at the National Museum of Korea in 1981. At that time, Cemedine C or Cemedine C mixed with microballoons was used for reinforcing the cracks. Conservation treatment focused on removing the past repair materials and reinforcing the physically fragile parts by joining and restoring them based on the examination of the preservation condition. in addition, the area around the restored part was colored for future exhibition.

• Journal of Conservation Science
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• v.31 no.2
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• pp.131-145
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• 2015

Cultural assets restoration is being considered highly as a practical way to extend the lifespan of damaged cultural assets and re-highlight their value. However, restoration process has been mostly dependent on the manual work involving the experience and skill of a person performing restoration, thereby requiring much time and effort. In recent, it became possible to apply a method allowing restoration to be performed more accurately and easily according to the material characteristics and shape of cultural assets. Namely, it is to use a method of printing out the 3D shape data computed in computer as real object by using 3D printer for the restoration that has been performed manually. The missing part of a cultural asset is computed into computer data first and is printed out by using 3D printer to undergo a simple shaping process. The result of 3D printer application showed that repetitive output and shape and figure revision of digital data were possible, and it was possible to improve the degree of completedness of restoration through test output using various types of restoration materials using various materials. For the purpose of verifying the possibility of applying 3D printer to restore missing part of earthenware, two pieces of modern reproductions, namely, the Seven Treasure Incense Burner and Earthenware with Wagon Wheel Decoration, were artificially damaged. The restoration result showed that compared to manual work, it showed better effectiveness in curtailing work time and reproducing accurate shape. On the other hand, secondary manual work was slightly needed for detailed binding and to vividly express surface texture.

• Korean Journal of Heritage: History & Science
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• v.43 no.3
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• pp.26-47
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• 2010

When the term conservation is used with regard to excavated features, it means not only conservation but also restoration. Restoring the features here does not imply restoring their original form but restoring their form at the moment of excavation. That means, the conservation of excavated features includes the concept of both reparation and restoration. The way of conserving excavated features can be largely categorized into on-site conservation and transfer conservation. On-site conservation means to conserve excavated features as they were at the excavation site. It can be further categorized into soil-covered on-site conservation, in which excavated features are covered with soil to prevent them from being damaged, and exposed on-site conservation in which the features were conserved as they were exposed. Transfer conservation is operated on the premise that excavated features are transferred to another place. It can be further categorized into original form transfer, transcribing transfer, reproduction transfer, and dismantlement transfer. Original form transfer refers to the method of moving the original forms of excavated features to another place. Transcribing transfer refers to moving some of the surfaces of excavated features to another place. Reproduction transfer refers to restoring the forms of excavated features in another place after copying the forms of excavated features at the excavation site. Dismantlement transfer refers to the method of restoring excavated features in a place other than the excavation site in the reverse order of dismantlement after dismantling the features at the excavation site. The most fundamental issue regarding conserving excavated features is the conservation of their original forms. However, the conservation of excavated features tends to be decided depending on a variety of conditions such as society, economy, culture, and local situations. In order to conserve excavated features more effectively, more detailed and specialized conservation methods should be created. Furthermore, continuing research is needed to find the most effective way of conserving them through exchange with other neighboring academic fields and scientific technology.

• Spatial Information Research
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• v.16 no.1
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• pp.19-32
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• 2008

Usually in South Korea, land cover type and topographic undulation are frequently changed even in a narrow area. However, most of researches using aerial LIDAR(LIght Detection And Ranging) data in abroad had been acquired in the study areas to be changed infrequently. This research was performed to explore reconstruction methodologies of 3D surface models considering the distribution of land cover type and topographic undulation. Composed of variously undulatory forests, rocky river beds and man-made land cover such as streets, trees, buildings, parking lots and so on, an area was selected for the research. First of all, the area was divided into three zones based on land cover type and topographic undulation using its aerial ortho-photo. Then, aerial LIDAR data was clipped by each zone and different 3D modeling processes were applied to each clipped data before integration of each models and reconstruction of overall model. These kinds of processes might be effectively applied to landscape management, forest inventory and digital map composition. Besides, they would be useful to resolve less- or over-extracted problems caused by simple rectangle zoning when an usual data processing of aerial LIDAR.

• 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.

• Proceedings of the Optical Society of Korea Conference
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• 2001.02a
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• pp.116-117
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• 2001

정밀 삼차원 미세 형상 측정기에서 성능의 관건은 고속, 고분해능으로 측정하는 것이다. 그러기 위해서는 공진주파수가 높아야 하고 스프링 상수가 작아야 한다. 광포획 현미경(optical trap microscope, OTM)은 광포획 된 마이크로 입자를 프로브로 사용하는 것으로 입자에 작용하는 복원력이 광에 의한 힘뿐이므로 스프링 상수가 낮다. 또한 공진주파수는 f=√k/m 으로 입자의 질량이 매우 작으므로 공진주파수도 비교적 높다. (중략)

• Proceedings of the Korea Multimedia Society Conference
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• 2000.11a
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• pp.218-223
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• 2000

영상에서 색상은 조명과 물체의 반사 특성에 의해 걸정되므로고 정확한 조명성분 추출을 통해 물체 고유의 색상을 복원할 수 있다. 물체 색상과 하이라이트 색상의 분포와 이들간의 관계를 잘 반영하여 모델링한 Dichromatic 반사 모델에서는, 3차원 RGB 공간에서의 하이라이트(highlight) 영역에 의한 클러스터 분포형상으로부터 표면반사벡터를 구해 이것을 조명벡터로 결정하였다. 그러나, 표면반사벡터의 방향은 물체색상의 영향을 받아 실제 조명벡터와 동일한 방향을 나타내지 못한다는 것을 실험을 통해 알 수 있었다. 실제적으로 하이라이트영역에 대한 클러스터는 물체 색상으로부터 조명색상에 근접한 방향으로 형성되며, 조명벡터로는 글러스터의 최대값으로 향하는 것을 취하는 것이 보다 정확하다는 특성이 있음을 확인하였다. 본 논문에서는 여러 가지 실험을 통해 이러한 특성이 타당함을 제시하고, 그래픽반사모델을 이용하여 하이라이트 색상에 대한 새로운 해석 방법을 제시한다.

• Journal of Surface Science and Engineering
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• v.48 no.4
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• pp.179-184
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• 2015

Quadrupole Mass Spectrometers (QMS) is a very useful tool in vacuum process diagnosis. Tungsten filament based ion sources are vulnerable to contamination from process gas monitoring. Common symptoms of quadrupole mass spectrometer malfunction is appearance of unwanted contaminant mass peaks or no detection of any ion peaks. We disassembled used quadrupole mass spectrometer and found out black insulating deposits on inside of ion source parts. Five steps of cleaning procedure were applied and almost full restoration of functions were confirmed in two types of closed ion source quadrupole mass spectrometer. By using a numerical modeling (CFD-ACE+) technique, the electric potential profile of ion source with/without insulating deposit was calculated and showed the possibility of quadrupole mass spectrometer malfunction by the deterioration of designed potential profile inside the ion source.

• Journal of the Korea Computer Graphics Society
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• v.9 no.1
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• pp.1-2
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• 2003

본 논문에서는 액체와 기체가 상호작용 하는 현상들에 대한 새로운 유체 애니메이션 기법을 액체 속 공기방울의 예를 사용하여 제시한다. 기존의 자유표면 시뮬레이션 기법들과는 달리 액체와 기체를 함께 시뮬레이션 할 경우에는 기체의 유동과 액체의 유동을 동시에 다루어야 하며 비중 차에 의한 부력과 경계면에서의 표면장력 등을 추가적으로 고려해야 한다. 유체의 토폴로지 변화를 쉽게 다루면서도 수치적 분산을 막기 위하여 유체 역학 분야의 VOF (Volume of Fluid) 기법과 프론트 추적 (Front-tracking) 기법을 혼합하여 사용하였다. 액체와 기체의 경계면은 마칭 큐브즈 알고리즘을 사용하여 폴리곤으로 복원된 후 버텍스 쉐이더 기술들을 사용하여 액체-기체 경계면의 광학적인 특성을 표현할 수 있었다.

• Korean Journal of Remote Sensing
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• v.27 no.5
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• pp.535-542
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• 2011

We extracted a surface displacement map of Canisteo Peninsula and the surrounding area in West Antarctica by applying 4-pass DInSAR technique to two ERS-1/2 tandem pairs and analyzed the surface displacement of glaciers and sea ice. In the displacement map, glaciers showed fast motion pushing the adjoining land-fast sea ice which has the displacement in the same direction as the glacier. Cosgrove ice shelf showed large displacement pushing the adjoining land-fast sea ice as well. Some sea ice indicated the displacement that is opposite to the land-fast sea ice. This was because the type of the sea ice is drift ice that is affected by ocean current. Therefore, we could confirmed the boundary between land-fast sea ice and drift ice. It was difficult to distinguish ice shelf from ice sheet because they showed similarities both in brightness of the SAR images and in fringe rates of the interferograms. However, a boundary between fast-moving ice shelf and stable ice sheet was easily confirmed in the displacement map after the phase unwrapping process.