• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.5
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• pp.511-517
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• 2009

A servo type angle of attack sensor using the null-seeking method is designed and its characteristics are analyzed in this study. Angle-of-attack in the null-seeking method is given by the probe rotation angle with respect to the body reference line when pressure difference measured in two holes on the probe becomes zero. This method provides highly accurate and uniform angle-of-attack measurements over all range. Hence, this kind of angle-of-attack sensor is adequate for unmanned aerial vehicles(UAVs). In this paper, we first analyze the requirements for developing angle-of-attack sensors. And the servo type angle-of-attack sensor is then designed and fabricated. The on-board angle-of-attack calculation algorithm is also developed. Finally, the characteristics of the developed angle-of-attack sensor are identified through MATLAB Simulink and wind tunnel tests.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.1
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• pp.9-14
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• 2020

In this paper, we studied on-board antenna(primary link/secondary link/satellite link) used in UAV Data-link system. As a result, it is ideal to configure the Data-link as a triple link to secure the flight stability of the UAV, but the communication link should be configured according to the operating platform. As a result of overseas R&D trend analysis, the on-board Data-link antenna is installed and operated in a location where it is easy to secure LOS. The primary link consists of a directional antenna for basic operation and an omni-directional antenna for emergency operation. The secondary link uses a monopole/dipole antenna in the UHF/C band. Satellite link has been developed to apply phased array antenna to improve UAV operability.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.16
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• pp.7285-7290
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• 2015

Background: Although radiotherapy is one of the most effective strategies in the treatment of cancers, it is associated with short and long term side effects on normal tissues. Zataria multiflora Boiss (Laminacea) (ZM) has several biological properties such as antioxidant and anti-inflammation activities.Here we investigated cell killing effects of a hydroalcoholic Zataria multiflora extract on cell death induced by ionizing radiation in a human glioblastoma cell line (A172) and human non-malignant fibroblasts (HFFF2) in vitro. Materials and Methods: A172 and HFFF2 cells were treated with a hydroalcoholic extract of dried aerial parts of Zataria multiflora at different concentrations (25, 50, 100, 150 and $200{\mu}g/ml$) and then exposed to ionizing radiation (IR). Cell proliferation and DNA fragmentation were evaluated. Thymol content in the extract was analyzed and quantified by HPLC methods. Results: A172 cell proliferation was significantly inhibited by ZM. The percentage cell survival was $91.8{\pm}8.57$ for cells treated with $200{\mu}g/ml$ of ZM extract alone while it was $76.0{\pm}4.27$ and $66.2{\pm}8.42$ for cells treated with ZM and exposed to IR at doses of 3Gy and 6Gy, respectively. Radiation-induced apoptosis in A172 cells was significantly increased following treatment with ZM at doses of $200{\mu}g/ml$. ZM extract did not exhibit any enhanced cell killing effects and apoptosis caused by IR on HFFF2 cells. Conclusions: These data show selective radiosensitization effects of ZM in A172 cells apparently due to increased radiation-induced apoptosis.

• The Korean Journal of Community Living Science
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• v.27 no.4
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• pp.863-873
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• 2016

The current study was undertaken to determine the effects of the ethanol extracts of loquat (Eriobotrya japonica Lindl.) seeds, flesh or leaves on the differentiation of 3T3-L1 cells and male pig preadipocytes. The cell number was measured with the MTT assay after trypsin digestion. The cell differentiation was determined by measuring the glycerol-3-phosphate dehydrogenase (GPDH) activity and triglyceride(TG) content. No cytotoxicity was observed from the loquat flesh and leaf ethanol extracts at concentrations of 5, 10, 25, 50, 100 or $200{\mu}g/mL$ in 3T3-L1 cells and pig preadipocytes. However, the cell viability of neither cell line were affected by up $50{\mu}g/mL$ of loquat seed ethanol extract. Treatment with the loquat seed and leaf ethanol extracts significantly suppressed the terminal differentiation of both cell lines in a dose-dependent manner, as confirmed by the decrease in the glycerol-3-phosphate dehydrogenase(GPDH) activity and TG content. Treatment with the loquat seed and leaf ethanol extracts inhibited the GPDH activity and reduced the TG content of both cell types more effectively than that with the loquat flesh ethanol extract. The most potent anti-adipogenic effect was obtained in the case of the ethanol extract of loquat seeds.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.67.1-67
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• 2003

Phytophthora blight is a devastating disease of pepper and occurs almost anywhere peppers are grown. Phytophthora blight is caused by Phytophthora capsici and this pathogen can infect every part of the plant by moving inoculum in the soil, by infecting water on surface, by aerial dispersal to sporulating lesions. Management of Phytophthora blight currently relies on cultural practices, crop rotation, and use of selective fungicides. Since these treatments are a short-term management, a classical breeding for development of resistant pepper against the Phytophthora is an alternative. So far some of the resistant cultivars have been on the market, but those are limited regionally and commercially. Therefore, ultimately an elite line resistant against this disease should be developed, if possible, by biotechnology. We have set out a series of work recently in order to develop Phytophthora resistant pepper cultivar. For the first time, the cDNA microarray analysis was peformed using an EST chip that holds around 5000 pepper EST clones to identify genes responsive to Phytophthora infection. Total RNA samples were obtained from Capsicum annuum PI201234 after inoculating P. capsici to roots and soil and exposed to the chip. .Around 900 EST clones were up-regulated and down-regulated depending on the two RNA sample tissues, leaf and root. From those, we have found 55 transcription factors that may be involved in gene regulation of the disease defense mechanism. Further and in detail information will be provided in the poster.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.6
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• pp.458-464
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• 2013

This paper presents an algorithm for autonomous landing approach of a unmanned aerial vehicle. The main purpose of the autonomous landing approach in this study is to help a safe landing at night. From any initial position of the aircraft when this function is engaged, a flight path command is generated from the initial position. The shortest combination of an initial circular arc, a straight line segment, and a final circular arc is chosen for the flight path that will lead the aircraft to one end of runway for a landing. The algorithm is initially validated through numerous simulations with various initial conditions of aircraft. Then it is successfully validated through a number of flight tests.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.11 no.2
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• pp.17-26
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• 1993

This study aims to develop an effective model of the optimum route determination by using digital terrain model. So in this study I select testing areas and analyse comparing the usual method with the digital terrain model method. And then I present one of the optimum route determination models by analysing an anticipated view and other roads according to the development plan. In usual method, the selected area was analysed by using panoramic terrestrial and aerial photograph. But in this study I represent the present terrain by using digital terrain materials which was acquired by a check form map of the selected area, and predict the route line according to the view points by using basic development plan. As a result of using the digital terrain model method in the optimum route determination with terrestrial photograph, it is possible to explain the terrain in detail when the present conditions terrain is analysed. As we can anticipated many sided road in large scale development plan with digital terrain materials which was used in analysing the present terrain, it is possible to lead to more effective route planning, landers planning and the optimum road determination than the usual method in the basic plan.

• Spatial Information Research
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• v.20 no.6
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• pp.45-57
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• 2012

The street trees in the urban areas provide an comfortable environment to the pedestrians and drivers and play important roles to absorb the carbons. Therefore, it is necessary to acquire and manage efficiently the location, height, and crown width of street trees. This study suggests a methodology to provide quantitative information of the street trees in urban areas including the quantity, location, height, and crown width of the trees. Therefore, it is more appropriate to add functionality of changing size of the crown width of the trees in the method. In addition, the positions of the street trees were selected using the fact that street trees are generally planted along the road in a straight line. An experiment on extracting street trees was conducted in parts of Osan-si, Gyeonggi-do and the suitability of the suggested methodology was evaluated by comparing the results to a 1/1,000 digital map. Through the experimental results, the minimum, maximum, and the root mean square errors of the position of street trees were 0.5m, 1.9m, and approximately ${\pm}0.4m$, respectively.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.4
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• pp.453-460
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• 2009

For constructing 3D information using aerial photograph or video sequences, left and right stereo images having different viewing angle should be prepared in overlapping area. In video sequences, left and right stereo images would be generated by mosaicing left and right slice images extracted in consecutive video sequences. Therefore, this paper is focused on generating left and right stereo mosaic images that are able to construct 3D information and video sequences could be made for the best use. In the stereo mosaic generation, motion parameters between video sequences should be firstly determined. In this paper, to determine motion parameters, free mosaic method using geometric relationship, such as relative orientation parameters, between consecutive frame images without GPS/INS geo-data have applied. After determining the motion parameters, the mosaic image have generated by 4 step processes: image registration, image slicing, determining on stitching line, and 3D image mosaicking. As the result of experiment, generated stereo mosaic image and analyzed result of x, y-parallax have showed.

• Applied Biological Chemistry
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• v.25 no.3
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• pp.142-149
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• 1982

Use efficiency of top-dressed labelled nitrogen(30% at ear formation stage) ranged 23 to 61%(five fields) with no clear difference between varieties. In high yield soil the use efficiency of top-dressed nitrogen was higher and more than 50% of fertilizer nitrogen in plant seemed to be taken up after ear formation, $^{15}N$ excess was greatest in grain indicating that top-dressed nitrogen translocates easily to grain. The difference of $^{15}N$ excess between grain and straw was greater in Tonsil line than in the local indicating faster nitrogen translocation in Tangil. Percent nitrogen derived from top-dressed nitrogen ranged 14 to 27% in aerial part. Two 3-hill plots per treatment could be enough for $^{15}N$ experiment under field condition if there is specific care.