• 보존과학연구
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• s.29
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• pp.221-238
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• 2008

Roofing tiles are very important archaeological artifacts which show science, architecture of that time, as well as information about the culture. It has been studied by many researchers steadily, but only focusing on archaeological, art historical and architectural study, so it is very difficult to find natural science research. Gyeongbokgung's roofing tiles were excavated from the ruins of same site, however glaze, body colour and shape of tiles are very diverse with the naked eye. Through natural science research which analyze the chemical composition and physical characteristics of roofing tiles's body and glaze examine the physical and chemical characteristics of each roofing tiles. the result of analazed roofing tiles is following. when roofing tiles were classified by 전암대자율 and chromaticity, each group has part of some matches. When you compare with green gazed traditional brick's glaze of Silla period, Gyeongbokgung roofing tiles have more $Al_2O_3$ and less PbO than Silla period's. We can see the technology of increasing firing temperature is better. and glaze colour depends on content of $Fe_2O_3$ and CuO. A lot of CuO tend to be more blue.

• Journal of KIISE:Software and Applications
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• v.34 no.8
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• pp.721-730
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• 2007

UML (Unified Modeling Language) is widely used to analyze and design target software. Developers also implement the target software based on the UML artifacts. However, it is difficult to validate whether the artifacts are generated to correspond to the modeling guidelines because the guidelines for UML modeling are described in natural language. This paper discusses rule based model checker focused on whether models are designed according to modeling methodology. We propose rules and their own checker, named GARDIAN, for UML model validation. The checkers are designed for COMET method for the real-time embedded system. We illustrate our checkers using Intelligent Robot system to validate our approach.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.6
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• pp.132-145
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• 2009

We present the framework for JND based Illumination and Color Restoration Using Edge-preserving filter for restoring distorted images taken under the arbitrary lighting conditions. The proposed method is effective for appropriate illumination compensation, vivid color restoration, artifacts suppression, automatic parameter estimation, and low computation cost for HW implementation. We show the efficiency of the mean shift filter and sigma filter for illumination compensation with small spread parameter while considering the processing time and removing the artifacts such as HALO and noise amplification. The suggested CRF (color restoration filter) can restore the natural color and correct color distortion artifact more perceptually compared with current solutions. For the automatic processing, the image statistics analysis finds suitable parameter using JND and all constants are pre-defined. We also introduce the ROI-based parameter estimation dealing with small shadow area against spacious well-exposed background in an image for the touch-screen camera. The object evaluation is performed by CMC, CIEde2000, PSNR, SSIM, and 3D CIELAB gamut with state-of-the-art research and existing commercial solutions.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.11 no.2
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• pp.133-156
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• 2013

Natural analogue studies play an important role in the safety case which requires multiple lines of evidence including the safety assessment for the geological disposal of radioactive wastes. In this study, foreign status of natural analogue studies was investigated by summarizing natural analogue results according to the research topics related with repository materials and radionuclide migration and retardation. Main results, issues, and applicability of the foreign natural analogue studies were also analyzed. The results of domestic natural analogue studies were classified into studies using uranium ore bodies, rocks, groundwaters, and archeological artifacts, respectively, and their main results were summarized. There are massive materials for natural analogue studies which have been carried out during last several decades but they have not been actively applied to the safety assessment and safety case development for the radioactive waster disposal. Thus, in this study, applicable methods of natural analogues were summarized and a methodology for improving their applicability was examined. Natural analogue study is apparently necessary to improve and illustrate the reliability of safety assessment for a radioactive waste repository. Therefore, it is necessary to develop a methodology and construct a natural analogue information database for the application of the results from natural analogue studies to safety case development.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.2
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• pp.112-117
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• 2008

Artifact corrections including normalization and attenuation correction were important for quantitative analysis in Nuclear Medicine Imaging. Normalization is the process of ensuring that all lines of response joining detectors in coincidence have the same effective sensitivity. Failure to account for variations in LOR sensitivity leads to bias and high-frequency artifacts in the reconstructed images. Attenuation correction is the process of the correction of attenuation phenomenon lies in the natural property that photons emitted by the radiopharmaceutical will interact with tissue and other materials as they pass through the body. In this paper, we will review the several approaches for normalization and attenuation correction strategies.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.585-590
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• 2000

Problems involved in the numerical analysis on the forced oscillation of nonlinear oscillators such a microbubble oscillation under ultrasound and Duffing oscillator were discussed. One of the problems is proper choice of the time scale of the driving force. which is related to the numerical artifacts due to the mismatch between the natural frequency of an oscillator(or bubble) and the characteristic frequency of the applied force. Such problem may occur in a nonlinear oscillator whose behavior is crucially dependent on the frequency of the applied force. The artificial resonance problem during the numerical evaluation of such nonlinear systems was also discussed.

• 전자공학회논문지 IE
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• v.47 no.3
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• pp.7-13
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• 2010

In this paper, an efficient contrast enhancement algorithm using weighted histogram modification is proposed. For contrast enhancement, histogram equalization (HE) and histogram stretching (HS) are effective techniques. However, HE and HS may have excessive contrast enhancement. Proposed method using weighted histogram modification produces better natural and enhanced results than those of conventional contrast enhancement methods without artifacts.

• 보존과학연구
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• s.28
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• pp.59-73
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• 2007

Wooden artifacts are biologically damaged by animals, insects, and micro-organisms. We focused on the evaluation of the antifungal and insecticidal activities of tree extracts to control deterioration of wooden cultural properties. 12 kinds of methanol extracts from 9 species of tree were investigated for their biocidal activities against two micro-organisms and two spices of insect. Most tree extracts showed fungicidal activities to Tyromyces palustris and Trametes versicolor. Among 12 different tree extracts, the strongest antifungal activity against T.palustris and T.versicolor was observed from the extracts of Pinus densiflora stem-bark extract and Pinus koraiensis leaf extracts. However, in the insecticidal activity test, Pinus densiflora stem-bark extracts against termite was relatively effective. Chemical compositions of methanol extracts were analyzed by gas chromatography/mass spectrometry. As a result, it was confirmed that development of biocide based on the natural extracts can be expected to conservate of wooden cultural properties.

• Journal of The Geomorphological Association of Korea
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• v.24 no.3
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• pp.119-131
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• 2017

Typical weathering landforms and phenomena including tafoni and gnamma are usually interpreted as man-made alteo (praying water bowl) or dragon-alteo by folklore researchers. Despite some terminological ambiguity, they are certainly natural weathering pits and are introduced in our discipline for fifty years, however, unfortunately most of them are interpreted as petroglyphs used and prepared for ritual ceremony. Several seemingly artificially-made rock holes are also found in many places, but most of them are weathered landforms by salt weathering. Author believes that communication effort to use common language and publish more researches in interdisciplinary journals are very essential to propagate scientific achievements made by geomorphologists to other discipline. Also geomorphologists specialized in weathering processes are encouraged to participate in preservation of stone artifacts and archaeological remains.

• Korean Journal of Plant Taxonomy
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• v.52 no.4
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• pp.235-245
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• 2022

Bhutan is endowed with rich biodiversity with several edible and useful fern species. Ferns have been used by local communities for centuries as vegetables, ethnobotanical artifacts, and as medicines. Owing to the limited study of edible and useful pteridophytes in the country, the knowledgebase remains poor. In this study, we attempt to document edible and useful fern species in the country scientifically while also providing an annotated checklist.