• Journal of IKEEE
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• v.22 no.3
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• pp.747-753
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• 2018

Currently, many companies have succeeded in logistics delivery experiments utilizing drone and report it. When a drone is used commercially, long-term flight is an important performance that a drone should have. However, unlike vehicles operated on the ground, drone is a vehicle that continues to consume energy when maintaining the current altitude or moving to the destination. Therefore, the drones can fly for a long time as the capacity of the battery is large, but the batteries with large capacity are restricted by heavy weight and it acts as a limiting factor in a commercial use. To address this issue, we attempt to compare how far we can fly than forward flight based on the flight pattern with the same energy consumption condition. In this paper, the comparison of energy consumption was performed in three flight pattern, forward flight without altitude change and forward flight with altitude change, by computer simulation and it shows the increasing of flight distances when the quadrotor fly with altitude change from high altitude to low altitude.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.20 no.2
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• pp.58-63
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• 2012

An altitude chamber, also known as a hypobaric chamber, is a device used during aerospace or high terrestrial altitude research or training to simulate the effects of high altitude on the human body. Although data from altitude chamber researches using experimental animals have been accumulated, studies in the humans exposed to hypobaric conditions are seldomly reported. Despite the importance of altitude chamber flight training in the field of aviation physiology, the hematological analysis of post-flight physiological changes has rarely been performed. The aims of the present study were to investigate the alterations in blood components during altitude chamber flight and to determine whether the differences between pre- and post-flight values are significant. Sixty experienced pilots in the Republic of Korea Air Force were enrolled in the altitude chamber flight training. Venous blood samples were obtained before and immediately after the flight. Compared with the pre-flight values($6.32{\times}10^3/mm^3$, $5.02{\times}10^6/mm^3$, 15.61 g/dL, respectively), white blood cell count, red blood cell count and hemoglobin level were significantly increased after the flight($6.77{\times}10^3/mm^3$, $5.44{\times}10^6/mm^3$, 16.26 g/dL; p=0.006, p=0.012, p<0.001, respectively). These alterations may be attributable to the exposure to hypobaric hypoxia, 100% oxygen supply for denitrogenation, considerable rise and fall in altitude and psychophysical stress due to these factors. In further studies, experimental groups and methods should be individualized to ensure objectivity and diversification. In addition, multiple time-frame analyses regarding the changing pattern of each blood component are also required to elucidate the physiological process for adapting to the high terrestrial altitude exposure.

• Journal of Korea Multimedia Society
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• v.24 no.11
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• pp.1538-1551
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• 2021

The current drone flight plan creation creates a flight path point of two-dimensional coordinates on the map and sets an arbitrary altitude value considering the altitude of the terrain and the possible flight altitude. If the created flight path is a simple terrain such as a mountain or field, or if the user is familiar with the terrain, setting the flight altitude will not be difficult. However, for drone flight in a city where buildings are dense, a safer and more precise flight path generation method is needed. In this study, using high-precision spatial information, we construct a drone safety flight map with a 3D grid map structure and propose a flight path search algorithm based on it. The safety of the flight path is checked through the virtual drone flight simulation extracted by searching for the flight path based on the 3D grid map created by setting weights on the properties of obstacles and terrain such as buildings.

• Journal of Astronomy and Space Sciences
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• v.31 no.1
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• pp.33-39
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• 2014

This paper describes an experimental approach to evaluate the effective doses of space radiations at high-altitude by combining the measured data from the Liulin-6K spectrometer loaded onto the air-borne RC-800 cockpit and the calculated data from CARI-6M code developed by FAA. In this paper, 15 exposed dose experiments for the flight missions at a high-altitude above 10 km and 3 experiments at a normal altitude below 4 km were executed over the Korean Peninsula in 2012. The results from the high-altitude flight measurements show a dramatic change in the exposed doses as the altitude increases. The effective dose levels (an average of $15.27{\mu}Sv$) of aircrew at the high-altitude are an order of magnitude larger than those (an average of $0.30{\mu}Sv$) of the normal altitude flight. The comparison was made between the measure dose levels and the calculated dose levels and those were similar each other. It indicates that the annual dose levels of the aircrew boarding RC-800 could be above 1 mSv. These results suggest that a proper procedure to manage the exposed dose of aircrew is required for ROK Air Force.

• Journal of Korea Society of Digital Industry and Information Management
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• v.7 no.3
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• pp.115-121
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• 2011

The flight information visualization of the aircraft is the system which is widely used to the threat against low altitude tasks and terrain altitude. But, it is difficult to implement the system because of restrictions that GPS data and huge geographic information should be stored. In this paper, it proposes economic DMM (Digital Moving Map) system for flight information visualization from open-source-base. First, the flight information is transferred from X-Plane through UDP and then demonstrated on the DMM system. In the proposed DMM system, flight information is visualized on the map information downloaded from an ArcGIS Map server using the mapping data between the present altitude of the aircraft and the terrain altitude. The result of this paper could be used an economic tool in the field of flight information visualization and the game algorithm research.

• Journal of Aerospace System Engineering
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• v.3 no.1
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• pp.1-5
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• 2009

The flight control of the T-50 advanced trainer is conducted by the digital FBW (Flight-by-Wire) control system. The system input data consist of flight conditions such as altitude, airspeed, and angle of attack. And the flight conditions of the aircraft are obtained from IMFP (Integrated Multi-Function Probe). The T-50 aircraft equip three IMFP sensors. To ensure reliability in flight condition data obtained from each IMFP sensor, the mean value of flight conditions is used as the input of the control system. In this study, the effect of an installation angle of IMFP sensors on estimation of flight altitude was investigated by flight test results in the supersonic region.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.590-593
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• 2005

Unmanned Helicopter has several abilities such as vertical Take off, hovering, low speed flight at low altitude. Such vehicles are becoming popular in actual applications such as search and rescue, aerial reconnaissance and surveillance. These vehicles also used under risky environments without threatening the life of a pilot. Since a small unmanned helicopter is very sensitive to environmental conditions, it is generally known that the flight control is very difficult problems. The nonlinear adaptive fuzzy controller design procedure and its applications for altitude control of unmanned helicopter were described in the paper. This research was concentrated on describing the design methodologies of altitude controller design for small unmanned helicopter acquiring autonomous take off and vertical movement. The design methodologies and performance of the altitude controller were simulated and verified with an adaptive fuzzy controller. Throughout simulation results, I showed that the proposed adaptive controllers have enhanced control performance such as robustness, effectiveness and safety, in the altitude control of the unmanned helicopter.

• Journal of Aerospace System Engineering
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• v.13 no.2
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• pp.1-9
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• 2019

This paper elaborates on the directional axis guidance and control algorithm used in mission flight for high altitude long endurance UAV. First, the directional axis control algorithm is designed to modify the control variable such that a strong headwind prevents the UAV from moving forward. Similarly, the guidance algorithm is designed to operate the respective algorithms for Fly-over, Fly-by, and Hold for way-point flight. The design outcomes of each guidance and control algorithm were confirmed through nonlinear simulation of high altitude long endurance UAV. Finally, the penultimate purpose of this study was to perform an actual mission flight based on the design results. Consequently, flight tests were used to establish the flight controllability of the designed guidance and control algorithm.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.2
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• pp.81-91
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• 2021

Drone related research has been increasing recently due to the development and distribution of commercial unmanned aerial vehicles. However, most of the previous studies focused on the accuracy and utility of drone surveying. For drones, the resolution of the result is determined according to the flight altitude, but since 70% of Korea is mountainous, it is necessary to analyze the quality of the drone image according to the flight plan. In this study, the quality of drone photogrammetry results according to flight plans was analyzed. The flight plan was established by fixed altitude and considering the height of the terrain. Images were acquired for both cases and data was processed to generate ortho images. As a result of evaluating the accuracy of the generated ortho image, the accuracy was found to be -0.07 ~ 0.09m. The accuracy of Case I and Case II did not show a significant difference, but for RMSE, Case I showed a good value. These results indicate that the drone flight plan affects the quality of the results. Also, when flying at a fixed altitude, II showed a lower value than the originally set overlap according to the altitude of the object. In future surveys using drones, flight planning taking into account the height of the object will contribute to the improvement of the quality of the results.

• Korean Journal of Environmental Biology
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• v.37 no.4
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• pp.579-584
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• 2019

The flight characteristics of 11 cinereous vultures (Aegypius monachus) were analyzed by a global positioning system (GPS) tracker(WT-300; KoEco, Inc.). The wintering period in Korea averaged 131 days (SD=17.4) and the average flight rate was 19.6%. The flight altitude was below 100 m for 21.6% of the flight, 101-200 m for 25.3%, 201-300 m for 19.0%, and below 300 m for 65.9%. There was a positive correlation (r=0.929) between the hourly flight rate and altitude. The predominant monthly flight altitude was 101-200 m (p<0.05). The wintering cinereous vultures lowered their flight rate and flew at an altitude of less than 300 m. This is thought to be an efficient way to find food through social interaction.