• Current Research on Agriculture and Life Sciences
• /
• v.32 no.3
• /
• pp.159-163
• /
• 2014

Agricultural unmanned helicopters have become a new paradigm for aerial application. Yet, such agricultural helicopters require easy and affordable attitude control systems. Therefore, this study presents an affordable attitude measurement system using a DCM (direction cosine matrix) algorithm that would be applied to agricultural unmanned helicopters. An IMU using a low-cost MEMS and an algorithm to estimate the attitude of the helicopter were applied in a gimbals structure to evaluate the accuracy of the attitude measurements. The estimation errors in the attitude were determined in comparison with the true angles determined by absolute position encoders. The DCM algorithm and sensors showed an accuracy of about 1.1% for the roll and pitch angle estimation. However, the accuracy of the yaw angle estimation at 3.7% was relatively larger. Such errors may be due to the magnetic field of the stepping motor and encoder system. Notwithstanding, since the intrinsic behavior of the agricultural helicopter remains steady, the determination of attitude would be reliable and practical.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.12 no.4
• /
• pp.158-168
• /
• 2009

As nation and society progresses, urban ground facilities and their management system get more complicated and the cost and effort to control the system efficiently grows exponentially. This study suggests to the deployment method of a sensor node by Wireless Sensor Network for controling the Urban Ground Facilities of National Facilities. First, we achieve the management facilities and method using the first analysis and then make the coverage of sensing and then set up the Sensor Node in Urban Ground Facilities. Second, we propose the solution way of repetition by the second analysis. And, we embody the GIS program by Digital Map and this method, we improve the reality by overlapping an aerial photo. Also we make an experience on the sensor node allocation using making program. we can remove the repetition sensor node about 50%, and we can confirm that the sensor nodes are evenly distributed on the road.

• Korean Journal of Remote Sensing
• /
• v.18 no.6
• /
• pp.359-367
• /
• 2002

In this paper, a new embedded wavelet packet image coder algorithm is proposed for an effective image coder using correlation between partitioned coefficients. This new algorithm presents parent-child relationship for reducing image reconstruction error using relations between individual frequency sub-bands. By parent-child relationship, every coefficient is partitioned and encoded for the zerotree data structure. It is shown that the proposed wavelet packet image coder algorithm achieves low bit rates and rate-distortion. It also demonstrates higher PSNR under the same bit rate and an improvement in image compression time. The perfect rate control is compared with the conventional method. These results show that the encoding and decoding processes of the proposed coder are simpler and more accurate than the conventional ones for texture images that include many mid and high-frequency elements such as aerial and satellite photograph images. The experimental results imply the possibility that the proposed method can be applied to real-time vision system, on-line image processing and image fusion which require smaller file size and better resolution.

• Korean Journal of Remote Sensing
• /
• v.21 no.2
• /
• pp.99-111
• /
• 2005

A fuzzy logic based data integration was applied for geothermal potential mapping in Jeju Island. Several data sets, such as geological map, the density of drainage system, the distribution density of cinder cones, density of lineaments, aerial survey map for total magnetic intensity and total gamma ray, were collected as thematic map for the integration. Fuzzy membership function for all thematic maps were compared to the locations of the spa, which were used as ground-truth control points. The older geology, the lower density of drainage, cinder cones and lineaments, and the lower intensity of magnetic and gamma ray were showed the higher fuzzy membership function values, respectively. After integrating all thematic maps, the results of gamma operator with the gamma value of 0.75 was the highest success rate, and new geothermal potential zone is prospected in western north part of Jeju Island.

• Korean Journal of Medicinal Crop Science
• /
• v.27 no.1
• /
• pp.38-44
• /
• 2019

Background: Taraxacum platycarpum has been used in traditional medicine in Korea to treat intoxication and edema and as a diuretic. According to previous reports, it has anti-cancer, anti-gastritis, and anti-inflammation effects. However, the improvement effect of T. platycarpum on rheumatoid arthritis has not been investigated. The anti-oxidative and anti-inflammation effects of the aerial parts of T. platycarpum are different from those of its subterranean parts. Thus, we evaluated the effect of the water extracts of Taraxaci radix (WTR) on type II collagen-induced rheumatoid arthritis (CIA) in animal models. Methods and Results: Rheumatoid arthritis was induced by type II collagen. WTR (100 mg/kg and 500 mg/kg) was administered to the animal models. Methotrexate was used as the positive control. The levels of interleukin-6, TNF-alpha, and type II collagen IgG in the animals were measured by using enzyme-linked immunosorbent assay. Treatment with 500 mg/kg WTR decreased the serum levels of interleukin-6, TNF-alpha, and collagen IgG in the CIA models. Moreover, treatment with WTR diminished the arthritisinduced swelling of the hind legs and monocyte infiltration in the bloodvessels of the animal models. Conclusions: These results indicate that WTR has the potential to improve rheumatoid arthritis by reducing the levels of inflammatory cytokines such as interleukin-6 and TNF-alpha. However, further experiments are required to elucidate the influence of WTR on signal transduction in vitro and in vivo.

• Journal of Advanced Navigation Technology
• /
• v.23 no.4
• /
• pp.289-295
• /
• 2019

Maritime back-up navigation system in port approach requires a horizontal accuracy of 10 meters in IALA (International Association of Lighthouse Authorities) recommendations. eLoran which is a best back-up navigation system that satisfies accuracy requirement has poor navigation performance depending signal environments. Especially, noise caused by multipath and electronic devices around eLoran antenna affects navigation performance. In this paper, Ship based Navigation Back-up system using UAV on Interference is designed to satisfy horizontal accuracy requirement. To improve the eLoran signal environment, UAVs are equipped with camera, IMU sensor and eLoran antenna and receivers. This proposed system is designed to receive eLoran signal through UAV-based receiver and control UAV's position and attitude within Landmark around area. The ship-based positioning using eLoran signal, vision and attitude information received from UAV satisfy resilient and robust navigation requirements.

• Korean Journal of Construction Engineering and Management
• /
• v.23 no.2
• /
• pp.45-53
• /
• 2022

The purpose of this study is to present a model for analyzing construction errors of reinforced concrete pile foundations using drones. First, a drone is used to obtain an aerial image of the construction site, and an orthomosaic image is generated based on those images. Then, the circular pile foundation is automatically recognized from the orthomosaic image by using the Hough transform circle detection method. Finally, the distance is calculated based on the the center point of the reinforced concrete pile foundation in the overlapped data. As a case study, the proposed concrete concrete pile foundation construction quality control model was applied to the real construction site in Incheon to evaluate the proposed model.

• Fisheries and Aquatic Sciences
• /
• v.24 no.10
• /
• pp.319-329
• /
• 2021

In the search for antibiotic alternatives from safe and effective medicinal plants against fish pathogenic bacteria, we found that a combined extract (CE) of 1:1 (w/w) ratio of Angelica gigas Nakai roots and aerial parts of Artemisia iwayomogi Kitamura showed antibacterial activity against the fish pathogenic bacteria. By antibacterial activity-guided fractionations and isolations, five compounds were isolated and identified as decursinol angelate (1), decursin (2), xanthotoxin (3), demethylsuberosin (4), and 2,4-dihydroxy-6-methoxyacetophenone (5) through spectroscopic analyses, such as nuclear magnetic resonance (NMR) and mass spectrometry (MS). Among the compounds, 1 and 2 showed the highest antibacterial activities against Streptococcus iniae and Vibrio anguillarum, showing minimum inhibitory concentrations (MICs) of 62.5-250 ㎍/mL. Compounds 3, 4, and 5 were also found to be active, with MICs of 31.25-1,000 ㎍/mL for those strains. Furthermore, active compounds, 1 and 2 in CE were simultaneously quantified using high-performance liquid chromatography-tandem MS (HPLC-MS/MS). The average contents of 1 and 2 in CE was 3.68% and 6.14%, respectively. The established method showed reliable linearity (r² > 0.99), good precision, accuracy, and specificity with intra- and inter-day variations of < 2 % and recoveries of 90.13%-108.57%. These results may be helpful for establishing the chemical profile of CE for its commercialization as an antibiotic alternative in aquaculture.

• The Journal of the Convergence on Culture Technology
• /
• v.8 no.4
• /
• pp.173-179
• /
• 2022

Through the 2014 Donbas conflict and the 2022 Ukraine-Russia war, we are experiencing that the command of the air is no longer only secured by the Air Force. Long-range surveillance reconnaissance and strikes carried out by the Air Force could be replaced by drones and missiles, and the enemy's aerial attacks could be controlled by air defense systems such as Panchir and portable anti-aircraft missiles, allowing ground forces to carry out maneuvers freely. In other words, it is much more advantageous for the air force and the navy to take control of the air through long-distance operations, and the ground forces should support them. Therefore, this study aims to consider the cost-effectiveness aspect of the delivery command of the air; it provides implications for quickly responding to enemy air attacks by developing the air defense weapon system, drones, missiles, precision-guided munitions, etc rather than focusing on expensive fighter jets.

• Journal of Advanced Navigation Technology
• /
• v.26 no.5
• /
• pp.312-318
• /
• 2022

Currently, the Republic of Korea is facing the problem of a decrease in military service resources due to the demographic cliff, and is pursuing military restructuring and changes in the military force structure in order to respond to this. In this situation, the Army is pushing forward the deployment of a drone-bot combat system that will lead the future battlefield. The battlefield of the future will be changed into an integrated battlefield concept that combines command and control, surveillance and reconnaissance, and precision strike. According to these changes, unmanned combat system, including dronebots, will be widely applied to combat situations that are high risk and difficult for humans to perform in actual combat. In this paper, as one of the countermeasures to these changes, autonomous behavior software with a BDI architecture-based decision-making system was developed. The autonomous behavior software applied a framework structure to improve applicability to multiple models. Its function was verified in a PC-based environment by assuming that the target UAV is a battalion-level surveillance and reconnaissance UAV.