• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.38 no.5
• /
• pp.490-498
• /
• 2010

This paper presents an autonomous target tracking approach and technique for transmitting ground control station image periodically for an unmanned aerial vehicle using onboard gimbaled(pan-tilt) camera system. The miniature rotary UAV which was used in this study has a small, high-performance camera, improved target acquisition technique, and autonomous target tracking algorithm. Also in order to stabilize real-time image sequences, image stabilization algorithm was adopted. Finally the target tracking performance was verified through a real flight test.

• Journal of Korean Society for Geospatial Information Science
• /
• v.21 no.4
• /
• pp.135-142
• /
• 2013

This study aims to seek adequate and optimized method of applying high quality three-dimensional spatial data created via high-resolution digital aerial photograph image and aerial LiDAR data onto three-dimensional planning of environmentally friendly, ecological restoration of rivers in accordance with irrigation and flood control objectives of urban rivers. Through three-dimensional modeling of before and after the restoration, the research also offers basic information regarding restorations of rivers. Also the transition from the conventional two-dimensional planning into three-dimensional planning environment using smart spatial information acquire accuracy of river analysis, analyze possible civil complaints and suggest solutions to potential problems.

• Journal of Aerospace System Engineering
• /
• v.13 no.6
• /
• pp.36-42
• /
• 2019

This research illustrates how the simulation environment for operating the simultaneous man/unmanned aerial vehicle teaming is constructed. X-Plane program, HILS for the ducted fan aircraft (unmanned) and CTLS (manned aircraft) with communication devices are interfaced to simulate the basic co-operational flight. The X-plane and HILS can allow operators to experience the maned and unmanned aircraft operation in the airspace on the ground in turn they can perform various simulated missions in advance before the actual flight. For the test purpose, the data link between man/unmanned aircraft and ground control station is examined using C Band and UHF radio channels by the manned aircraft.

• Journal of Biosystems Engineering
• /
• v.35 no.5
• /
• pp.302-309
• /
• 2010

Aerial application using an unmanned agricultural helicopter would allow precise and timely spraying. The attitude of a helicopter depends on a number of dynamic variables for roll-balanced flight. Laterally tilting behavior of a helicopter is a physically intrinsic phenomenon while hovering and forwarding. In order to balance the fuselage, the rotor should be counter-tilted, resulting in the biased down-wash. The biased spraying toward right side causes uneven spray pattern. In this study, a raised tail rotor system for the roll-balanced helicopter was studied. Thrust of the tail rotor system was measured and theoretically estimated for the fundamental database of the roll-balanced helicopter design. The estimated tail thrust and roll-moment would be used to design the raising height of tail rotor and roll balancing dynamics. The unmanned agricultural helicopter required the tail rotor thrust of about 39.2 N (4.0 kgf) during hovering with a payload of 235.4 N (24 kgf). A raised tail rotor system would compensate for the physical tilt phenomena. A further attitude control system of helicopter would assist roll-balanced aerial spray application.

• Journal of Korea Multimedia Society
• /
• v.21 no.8
• /
• pp.897-908
• /
• 2018

In this paper, we propose a security framework for a cluster drones network using the MAVLink (Micro Air Vehicle Link) application protocol based on FANET (Flying Ad-hoc Network), which is composed of ad-hoc networks with multiple drones for IoT services such as remote sensing or disaster monitoring. Here, the drones belonging to the cluster construct a FANET network acting as WTRP (Wireless Token Ring Protocol) MAC protocol. Under this network environment, we propose an efficient algorithm applying the Lightweight Encryption Algorithm (LEA) to the CTR (Counter) operation mode of WPA2 (WiFi Protected Access 2) to encrypt the transmitted data through the MAVLink application. And we study how to apply LEA based on CBC (Cipher Block Chaining) operation mode used in WPA2 for message security tag generation. In addition, a modified Diffie-Hellman key exchange method is approached to generate a new key used for encryption and security tag generation. The proposed method and similar methods are compared and analyzed in terms of efficiency.

• Advances in Traditional Medicine
• /
• v.7 no.2
• /
• pp.150-156
• /
• 2007

Bacopa monnieri is being used in the traditional system of medicine for a variety of ailments. In the present study, the ethanolic extract of Bacopa monnieri aerial parts has been studied for its wound healing activity using various models in rats. Significant increase in wound contraction and skin breaking strength were observed in the excision and incision wound models respectively. There was also significant increase in hydroxyproline content, DNA content, superoxide dismutase activity, catalase activity, glutathione level and decrease in the level of thiobarbituric acid reactive substances in the $12^{th}$ day post wounding tissue of experimental rats in the ethanol extract treated groups with respect to the control group. The effect of the extract was found to be comparable with the standard drug nitrofurazone. From the results it may be concluded that the plant Bacopa monnieri is endowed with significant wound healing activity, thereby justifying its use in the traditional medicine. Saponins may be responsible for the observed wound healing activity.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.10 no.5
• /
• pp.890-896
• /
• 2006

It's very difficult to acquire the accurate GCP(Ground Control Point) in the urban center and forest aerial photo because of occurring of irregular multi-path error. The purpose of this study is to apply the CPS and the EDM system for 3D orthophoto in the small areas. GCPs surveyed by accuracy triangulation from EDM after from triangulation points to a fiducial point at study area used to GPS. And I have a comment on how to use areal orthophoto for future 3D-GIS after 3D-Modelling using areal orthophoto. As the results, EDM surveying could resolve multi-path error according to GPS surveying and It is possible for using aerial orthophoto on the basis of the 3D-GIS database.

• Journal of Ginseng Research
• /
• v.6 no.2
• /
• pp.168-203
• /
• 1982

Effects of soil moisture on growth of Panax ginseng, of various factors on soil moisture, and of moisture on nutrition, quality, physiological disorder, diseases and insect damage were reviewed. Optimum soil moisture was 32% of field capacity with sand during seed dehiscence, and 55-65% for plant growth in the fields. Optimum soil moisture content for growth was higher for aerial part than for root and higher for width than for length. Soil factors for high yield in ginseng fields appeared to be organic matter, silt, clay, agreggation, and porosity that contributed more to water holding capacity than rain fall did, and to drainage. Most practices for field preparation aimed to control soil moisture rather than nutrients and pathogens. Light intensity was a primary factor affecting soil moisture content through evaporation. Straw mulching was best for the increase of soil moisture especially in rear side of bed. Translocation to aerial part was inhibited by water stress in order of Mg, p, Ca, N an Mn while accelerated in order of Fe, Zn and K. Most physiological disorders(leaf yellowing, early leaf fall, papery leaf spot, root reddening, root scab, root cracking, root dormancy) and quality factors were mainly related to water stress. Most critical diseases were due to stress, excess and variation of soil water, and heavy rain fall. The role of water should be studied in multidiciplinary, especially in physiology and pathology.

• Archives of Pharmacal Research
• /
• v.27 no.6
• /
• pp.600-603
• /
• 2004

(＋）-Dehydrovomifoliol (1）. 3-hydroxy-5$\alpha$,6$\alpha$-epoxy-$\beta$-ionone (2）, vitexin 7 -O-$\beta$-D-glucopyrano-side (3）, and vitexin 2'-O-$\beta$-D-glucopyranoside (4） were isolated as new constituents from the aerial parts of Beta vulgaris var. cicla. Compounds 3 and 4 demonstrated hepatoprotective activity with values of 65.8 and 56.1％, respectively, in primary cultured rat hepatocytes with $CCl_4$-induced cell toxicity, compared to controls. This was comparable to that of silibinin (69.8％） which was used as a positive control.trol.

• Electronics and Telecommunications Trends
• /
• v.35 no.2
• /
• pp.38-49
• /
• 2020

In recent years, the unmanned aerial vehicle (UAV) assisted mobile free space optical (FSO) communication technique has attracted considerable attention regarding its aims to provide improved communication conditions for fixed-to-fixed FSO network and promising fronthaul and backhaul solutions for 5G+ wireless networks. This can be attributed to its outstanding advantages such as fast deployment and flexible network configuration. The UAV-assisted mobile FSO system can be used to provide cost-effective internet services in rural and remote areas and in hotspot areas that are characterized by increased data traffic. Additionally, it can be used to provide secure communication services under emergency circumstances. In this report, we review recent R&D trends in wireless network technology employing the UAV-assisted mobile FSO technique and key technologies for mobile FSO wireless networks. Furthermore, we introduce drone-based mobile FSO terminals and control systems that we have developed.