• Spatial Information Research
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• v.19 no.1
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• pp.51-59
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• 2011

We produced true ortho images after interpolating occlusion areas and relief displacement of building as well as producing ortho-images to use backward image of ADS which is a aerial digital camera of line type. Also, I was able to produce high quality ortho-images using a small mount of Ground Control Points(GCP) relatively to compare to frame type camera from the evaluation of horizontal position accuracy using ground check points, photo control points for the verification of ortho-images and true-ortho images. Also, I was able to verify the effectiveness in interpolating occlusion areas cause the length overlap was 100% when producing true-ortho images of line type camera.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.36 no.3
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• pp.127-134
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• 2018

Electric transmission towers are facilities to transport electrical power from a plant to an electrical substation. The towers are connected using power lines that are installed with a proper sag by loosening the cable to lower the tension and to secure the sufficient clearance from the ground or nearby objects. The power line sag may extend over the tolerance due to the weather such as strong winds, temperature changes, and a heavy snowfall. Therefore the periodical mapping of the power lines is required but the poor accessibility to the power lines limit the work because most power lines are placed at the mountain area. In addition, the manual mapping of the power lines is also time-consuming either using the terrestrial surveying or the aerial surveying. Therefore we utilized multiple overlapping images acquired from a low-cost drone to automatically reconstruct the power lines in the object space. Two overlapping images are selected for epipolar image resampling, followed by the line extraction for the resampled images and the redundant images. The extracted lines from the epipolar images are matched together and reconstructed for the power lines primitive that are noisy because of the multiple line matches. They are filtered using the extracted line information from the redundant images for final power lines points. The experiment result showed that the proposed method successfully generated parabolic curves of power lines by interpolating the power lines points though the line extraction and reconstruction were not complete in some part due to the lack of the image contrast.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.4
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• pp.277-285
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• 2004

We present a new hybrid stereo matching technique in terms of the co-operation of area-based stereo and feature-based stereo. The core of our technique is that feature matching is carried out by the reference of the disparity evaluated by area-based stereo. Since the reference of the disparity can significantly reduce the number of feature matching combinations, feature matching error can be drastically minimized. One requirement of the disparity to be referenced is that it should be reliable to be used in feature matching. To measure the reliability of the disparity, in this paper, we employ the self-consistency of the disunity Our suggested technique is applied to the detection of 3D line segments by 2D line matching using our hybrid stereo matching, which can be efficiently utilized in the generation of the rooftop model from urban imagery. We carry out the experiments on our hybrid stereo matching scheme. We generate synthetic images by photo-realistic simulation on Avenches data set of Ascona aerial images. Experimental results indicate that the extracted 3D line segments have an average error of 0.5m and verify our proposed scheme. In order to apply our method to the generation of 3D model in urban imagery, we carry out Preliminary experiments for rooftop generation. Since occlusions are occurred around the outlines of buildings, we experimentally suggested multi-image hybrid stereo system, based on the fusion of 3D line segments. In terms of the simple domain-specific 3D grouping scheme, we notice that an accurate 3D rooftop model can be generated. In this context, we expect that an extended 3D grouping scheme using our hybrid technique can be efficiently applied to the construction of 3D models with more general types of building rooftops.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.86-91
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• 2016

To solve the problem of the excessive error caused by using a single value for the shielding effect of the neutral line of an electric power distribution line in the calculation of the voltage it induces in a telecommunication line, the general expression that was previously developed to reflect the mechanism of voltage induction by a distribution line with multiple grounds is employed in this paper to represent the relationship between the leakage current rates at each ground pole. In this way, the formula for calculating the shielding effect of the neutral line can be factorized against the unbalanced current flowing in the neutral line, which is the root current of induction. This shielding coefficient of the neutral line is not constant, but can vary when a range of induced voltages is generated in the whole power distribution line. The calculation method developed herein reduces the error rate to one tenth of that of the existing calculation result in the case of overestimation and increases it by 14% in the case of underestimation.

• Natural Product Sciences
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• v.29 no.2
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• pp.98-103
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• 2023

Sphaeranthus africanus is commonly used as a traditional remedy for sore throats and pain treatment in Vietnam. The aerial parts have been studied for its anti-inflammatory and anti-proliferative properties. However, the antioxidant and antidiabetic potential of the plant has not been explored. In this work, hydrophilic extracts of the plant's aerial parts were prepared in order to investigate its antioxidant and anti-diabetic properties. Also, the cytotoxicity of the root was evaluated and compared to that of the aerial parts. All of the extracts inhibited lipid peroxidation with IC₅₀ values ranging from 2.05 to 3.56 ㎍/mL, indicating substantial antioxidant activity. At an IC₅₀ value of 4.80 ㎍/mL, the 50% ethanol extract exhibited the most potent inhibition of α-glucosidase. The cytotoxic activity of root extracts is 2 to 5-fold less than that of the aerial parts. Nevertheless, dichloromethane and ethyl acetate extracts of the root demonstrated a selective effect on leukemia cells, with no harm towards the normal HEK-293 cell line. This work provides a scientific support for the antioxidant and antidiabetic activity of the plant. Hence, it may find a promising material for the development of novel antioxidant and antidiabetic agents. More research can be conducted on the phytochemistry and anticancer activities of the plant's root.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.11
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• pp.5843-5848
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• 2012

Aim: Developing antitumor drugs from natural products is receiving increasing interest worldwide due to limitations and side effects of therapy strategies for the second leading cause of disease related mortality, cancer. Methods: The antiproliferative activity of a methanolic extract from the aerial parts of Marrubium persicum extract was assessed with the MCF-7 breast cancer cell line using the MTT test for cell viability and cytotoxicity indices. In addition, antioxidant properties of the extract were evaluated by measuring its ability to scavenge free DPPH radicals. Moreover, the total phenolic and flavonoid content of the extract was determined based on Folin-Ciocalteu and colorimetric aluminum chloride methods. Results: The findings of the study for the antiproliferative activity of the methanolic extract of M. persicum showed that growth of MCF-7 cells was inhibited by the extract in a dose and time dependent manner, where a gradual increase of cytotoxicity effect has been achieved setting out on 200 ${\mu}g/mL$ concentration of the plant extract. The antioxidant assay revealed that the extract was a strong scavenger of DPPH radicals with an $RC_{50}$ value of 52 ${\mu}g/mL$. The total phenolic and flavonoids content of the plant extract was 409.3 mg gallic acid equivalent and 168.9 mg quercetin equivalent per 100g of dry plant material. Conclusion: Overall, M. persicum possesses potential antiproliferative and antioxidant activities on the malignant MCF-7 cell line that could be attributed to the high content of phenolics and flavonoids, and therefore warrants further exploration.

• Journal of Ocean Engineering and Technology
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• v.21 no.4
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• pp.15-20
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• 2007

The harbor siltation by longshore sediment transports has become a serious problem on the East Coast of Korea. A reasonable prediction of the longshore sediment rate is important to approach the siltation problem effectively. In the recently developed 1-line model, the empirical constants of the sediment transport formula, which include the absolute quantity of sediment transport rate and the spatial distribution of breaking wave height by wave deformation, are treated as calibration parameters. Since these constants should be determined by the very long-term shoreline data, the longshore sediment rates are much more reasonable values. The method was applied to Hupo Beach, which has experienced heavy siltation. The authors also discuss long-term shoreline change using aerial photos and the observed wave-induced current patterns. According to the result, the SW-direction sediment transport rate was $146,892m^3/year$, and the NE direction was $2,694,450m^3/year$ at Hupo Beach for the last 11 years. The siltation in Hupo Harbor might be affected by the NE-direction sediment transport from Hupo Beach.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.6
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• pp.1414-1418
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• 2013

In this paper, analyzed of UAVs operation altitude and range from the point of view of the data link. UAVs operation altitude is determined by the specification of the mission equipment and operational purposes. The link-of-sight analysis of data link equipment before deciding the unmanned aircraft operation altitude conditions should be considered. If GDT=0m installation then 32dBi antenna apply 15,779 meter is operation altitude. 44dBi antenna 7,927 meters. Operating altitude perspective, high-gain antenna is recommended of the long range communication.

• Journal of Korean Society for Geospatial Information Science
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• v.10 no.1 s.19
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• pp.77-82
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• 2002

This study try to attempt to manage on-line system of land cadastral by computing land registration information, for application to computerized cadastral work through Geo-Spatial Information System. And also, in order to consult D/B of cadastral information, cadastral non-coincidence area uncapable to D/B when land-survey, taking advantage of GSIS drawing made by the present condition drawing and the aerial photograph survey by general survey, makes actual cadastral control point by some selected investigators. And so, it can be compared and analysed by the result of the present survey and, through the interpretation of the relatives, it aims to improve the precision of survey technique in consulting cadastral information D/B in the future.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.301-303
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• 2003

The extraction of 3D road network from high-resolution aerial images is still one of the current challenges in digital photogrammetry and computer vision. For many years, there are many researcher groups working for this task, but unt il now, there are no papers for doing this with TLS (Three linear scanner), which has been developed for the past several years, and has very high-resolution (about 3 cm in ground resolution). In this paper, we present a methodology of road extraction from high-resolution digital imagery taken over urban areas using this modern photogrammetry’s scanner (TLS). The key features of the approach are: (1) Because of high resolution of TLS image, our extraction method is especially designed for constructing 3D road map for next -generation digital navigation map; (2) for extracting road, we use the global context of the intensity variations associated with different features of road (i.e. zebra line and center line), prior to any local edge. So extraction can become comparatively easy, because we can use different special edge detector according different features. The results achieved with our approach show that it is possible and economic to extract 3D road data from Three Linear Scanner to construct next -generation digital navigation road map.