• Korean Journal of Remote Sensing
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• v.37 no.5_2
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• pp.1259-1268
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• 2021

The 2nd Geostationary Ocean Color Imager (GOCI-II) is the successor to the Geostationary Ocean Color Imager (GOCI), which employs one near-ultraviolet wavelength (380 nm) and eight visible wavelengths(412, 443, 490, 510, 555, 620, 660, 680 nm) and three near-infrared wavelengths(709, 745, 865 nm) to observe the marine environment in Northeast Asia, including the Korean Peninsula. However, the multispectral radiance image observed at satellite altitude includes both the water-leaving radiance and the atmospheric path radiance. Therefore, the atmospheric correction process to estimate the water-leaving radiance without the path radiance is essential for analyzing the ocean environment. This manuscript describes the GOCI-II standard atmospheric correction algorithm and its initial phase validation. The GOCI-II atmospheric correction method is theoretically based on the previous GOCI atmospheric correction, then partially improved for turbid water with the GOCI-II's two additional bands, i.e., 620 and 709 nm. The match-up showed an acceptable result, with the mean absolute percentage errors are fall within 5% in blue bands. It is supposed that part of the deviation over case-II waters arose from a lack of near-infrared vicarious calibration. We expect the GOCI-II atmospheric correction algorithm to be improved and updated regularly to the GOCI-II data processing system through continuous calibration and validation activities.

• The Southeast Asian review
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• v.20 no.3
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• pp.263-297
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• 2010

The relics of the Southeast Asian civilizations in the first phase are found with the relics from India, China, and even further West of Persia and Rome. These relics are the historic marks of the ancient interactions of various continents, mainly through the maritime trade. The traces of the indic culture, which appears in the historic age, are represented in the textual records and arts, regarded as the essence of the India itself. The ancient Hindu arts found in various locations of Southeast Asia were thought to be transplanted directly from India. However, Neither did the Gupta Hindu Art of India form the mainstream of the Gupta Art, nor did it play an influential role in the adjacent areas. The Indian culture was transmitted to Southeast Asia rather intermittently than consistently. If we thoroughly compare the early Hindu art of India and that of Southeast Asia, we can find that the latter was influenced by the former, but still sustained Southeast Asian originality. The reason that the earliest Southeast Asian Hindu art is discovered mostly in continental Southeast Asia is resulted from the fact that the earliest networks between India and the region were constructed in this region. Among the images of Hindu gods produced before the 7th century are Shiva, Vishnu, Harihara, and Skanda(the son of Shiva), and Ganesha(the god of wealth). The earliest example of Vishnu was sculpted according to the Kushan style. After that, most of the sculptures came to have robust figures and graceful proportions. There are a small number of images of Ganesha and Skanda. These images strictly follow the iconography of the Indian sculpture. This shows that Southeast Asians chose their own Hindu gods from the Hindu pantheon selectively and devoted their faiths to them. Their basic iconography obediently followed the Indian model, but they tried to transform parts of the images within the Southeast Asian contexts. However, it is very difficult to understand the process of the development of the Hindu faith and its contents in the ancient Southeast Asia. It is because there are very few undamaged Hindu temples left in Southeast Asia. It is also difficult to make sure that the Hindu religion of India, which was based on the complex rituals and the caste system, was transplanted to Southeast Asia, because there were no such strong basis of social structure and religion in the region. "Indianization" is an organized expansion of the Indian culture based on the sense of belonging to an Indian context. This can be defined through the process of transmission and progress of the Hindu or Buddhist religions, legends about purana, and the influx of various epic expression and its development. Such conditions are represented through the Sanskrit language and the art. It is the element of the Indian culture to fabricate an image of god as a devotional object. However, if we look into details of the iconography, style, and religious culture, these can be understood as a "selective reception of foreign religious culture." There were no sophisticated social structure yet to support the Indian culture to continue in Southeast Asia around the 7th century. Whether this phenomena was an "Indianization" or the "influx of elements of Indian culture," it was closely related to the matter of 'localization.' The regional character of each local region in Southeast Asia is partially shown after the 8th century. However it is not clear whether this culture was settled in each region as its dominant culture. The localization of the Indian culture in Southeast Asia which acted as a network connecting ports or cities was a part of the process of localization of Indian culture in pan-Southeast Asian region, and the process of the building of the basis for establishing an identity for each Southeast Asian region.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.4
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• pp.218-227
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• 2006

Purpose: The HSV1-tk reporter gene system is the most widely used system because of its advantage that direct monitoring is possible without the introduction of a separate reporter gene in case of HSV1-tk suicide gene therapy. In this study, we investigate the usefulness of the reporter probe (substrate), $9-(4-[^{18}F]Fluoro-3-hydroxymethylbutyl)$guanine ($[^{18}F]FHBG$) for non-invasive reporter gene imaging using PET in HSV1-tk expressing hepatoma model. Materials and Methods: Radiolabeled FHBG was prepared in 8 steps from a commercially available triester. The labeling reaction was carried out by NCA nucleophilic substitution with $K[^{18}F]/K2.2.2.$ in acetonitrile using N2-monomethoxytrityl-9-14-(tosyl)-3-monomethoxytritylmethylbutyl]guanine as a precursor, followed by deprotection with 1 N HCl. Preliminary biological properties of the probe were evaluated with MCA cells and MCA-tk cells transduced with HSV1-tk reporter gene. In vitro uptake and release-out studies of $[^{18}F]FHBG$ were performed, and was analyzed correlation between $[^{18}F]FHBG$ uptake ratio according to increasing numeric count of MCA-tk cells and degree of gene expression. MicroPET scan image was obtained with MCA and MCA-tk tumor bearing Balb/c-nude mouse model. Results: $[^{18}F]FHBG$ was purified by reverse phase semi-HPLC system and collected at around 16-18 min. Radiothemical yield was about 20-25%) (corrected for decay), radiochemical purity was >95% and specific activity was around >55.5 $GBq/{\mu}\;mol$. Specific accumulation of $[^{18}F]FHBG$ was observed in HSV1-tk gene transduced MCA-tk cells but not in MCA cells, and consecutive 1 hour release-out results showed more than 86% of uptaked $[^{18}F]FHBG$ was retained inside of cells. The uptake of $[^{18}F]FHBG$ was showed a highly significant linear correlation ($R^2=0.995$) with increasing percentage of MCA-tk numeric cell count. In microPET scan images, remarkable difference of accumulation was observed for the two type of tumors. Conclusion: $[^{18}F]FHBG$ appears to be a useful as non-invasive PET imaging substrate in HSV1-tk expressing hepatoma model.