• Korean Journal of Applied Biomechanics
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• v.32 no.3
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• pp.80-86
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• 2022

Objective: The purpose of this study was to investigate the effects of three rotational jump conditions (standing jump, left rotational jump and right rotational jump) on stability through center of pressure (COP) and EMG variables analysis. Method: A total of 16 college students (age: 24.13 ± 7.17 years, height: 169.24 ± 8.23 cm, weight: 65.65 ± 13.88 kg) participated in this study. The study used wireless two COP plates and wireless eight channel EMG. The analyized variables were 11 variables for COP and RMS for EMG, which were analyzed using one-way analysis of variance with repeated measures according to three rotational jump conditions. Results: Among the COP variables, left rotational jump (LRJ) and right rotational jump (RRJ) were larger than standing jump (SJ) for left and right amplitude, area, total displacement, and average velocity for both feet among the variables of COP, and for area of the left foot, RRJ was larger than that of SJ. Among the EMG variables, there was no statistical difference between the muscle activations, but the muscle activity was significantly higher in the order of RRJ, LRJ, and SJ according to direction of rotation. Conclusion: Although the results of COP and EMG were not consistent through this study, it can be expected that the differences in COP was due to the amount of rotation during rotational jump-landing in the left and right directions, and that the EMG is determined by the lateral movements required for rotation.

• Journal of the Korea Institute of Military Science and Technology
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• v.18 no.4
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• pp.469-477
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• 2015

In this study, the characteristics of main wind direction, vertical temperature and wind speed profile near the Moseulpo airfield for HALE UAV(High Altitude Long Endurance Unmaned Aerial Vehicle) is investigated. The results are summarized as follows, main wind direction is governed by air mass according to season and local wind such as land-sea breeze. The directions of landing and take-off of HALE UAV will be selected as the south-east direction in June ~ August, north-west direction in October ~ March, and south-east direction at daytime in April ~ May, September. Annual variation of temperature at 100 hPa showed that temperature in summer season is lower than winter season. On the other hands, wind speed at 250 hPa in winter season is higher than summer season. The threshold values of temperature and wind speed for HALE UAV flight are $-75^{\circ}C$ and $90ms^{-1}$, which were determined by 5 % frequency value($1.96{\sigma}$), respectively.

• Journal of Advanced Navigation Technology
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• v.14 no.4
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• pp.479-488
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• 2010

The aim of this paper is to research the change in the turbulent flow and the AOA occurred by the wind perpendicular to the direction of runway according to the three-dimensional numerical analysis. The maximum amplitude of AOA variation on runway reached $6^{\circ}$ within 1 second because of the wake formed by the constructions in the vicinity of the airport. The overall effects appeared in aperiodic forms. It was also observed the rapid flow generated between the buildings shifted into the existing wake and eventually merged with it. It is expected thai the strong wake will cause instability during takeoff and landing.

• International Journal of Aeronautical and Space Sciences
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• v.18 no.4
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• pp.623-640
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• 2017

The full nonlinear equations of an unmanned aerial vehicle ground taxiing mathematical dynamic model are built based on a type of unmanned aerial vehicle data in LMS Virtual.Lab Motion. The flexible landing gear model is considered to make the aircraft ground motion more accurate. The electric braking control system is established in MATLAB/Simulink and the experiment of it verifies that the electric braking model with the pressure sensor is fitted well with the actual braking mechanism and it ensures the braking response speediness. The direction rectification control law combining the differential brake and the rudder with 30% anti-skid brake is built to improve the directional stability. Two other rectifying control laws are demonstrated to compare with the designed control law to verify that the designed control is of high directional stability and high braking efficiency. The lateral displacement increases by 445.45% with poor rectification performance under the only rudder rectifying control relative to the designed control law. The braking distance rises by 36m and the braking frequency increases by 85.71% under the control law without anti-skid brake. Different landing conditions are simulated to verify the good robustness of the designed rectifying control.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.8
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• pp.1124-1129
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• 2021

The application area based on UAV (Unmanned Aerial Vehicle) is continuously increasing as time passing by. In particular the UAVs which consist of more than four horizontal propellers and the functionality of VTOL (Vertical Take-Off and Landing) are utilized in diverse platforms and the application products due to their safety and aerodynamically simpler design and architectures. The most UAV missions are controlled by GCSs (Ground Control System). The GCSs are generally connected to the internet and get electrical map and environmental information such as temperature, humidity, wind speed, wind direction and so on. In this paper, we design a system for UAV system to have capability of approaching to a certain ship and monitoring her efficiently by using AIS (Auto Identification System) information. Furthermore we verify that adapting AIS on GCS side is more efficient through experiments.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.31 no.2
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• pp.89-94
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• 2023

Recently, domestic small airport development plans are being promoted centering on islands, and among them, Baengnyeong Island Airport is located very close to North Korea due to its geographical characteristics. In particular, since it is located in the P-518, which is prohibited airspace, it is essential to configure the arrival/departure flight procedure route similarly to the current ship in terms of securing flight safety. Therefore, in this study, a plan for airport location and facility scale was proposed by focusing on the runway operated for the purpose of aircraft operation through consultations with the Ministry of National Defense. It was proposed to meet the standards of the Airport Facility Act as an airport dedicated to domestic flights for airside facilities such as runway length and direction, target aircraft, landing pad, apron, runway and taxiway width appropriate for the topographical characteristics of Baengnyeong Island. As a result, the flight procedure is generally established as a two-way visual flight, but the 10-way arrival/departure procedure was planned to be changed to an instrument (non-precision) according to the specificity of the region. In addition, a flight procedure was established and presented for safe and systematic operation by reflecting the changes in airport facility size (landing pad, runway end safety area, etc.) following the change in instrument flight procedure in the visual flight procedure.

• Journal of the Korean Solar Energy Society
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• v.32 no.spc3
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• pp.262-268
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• 2012

In the recent research technical solutions have been studied to integrate renewable energy into unmanned aerial vehicles to use it as the main power source. As the weight of the aerial vehicle body is essential for its performance, we consider to use light-weight solar cell technology. Furthermore fuel cells are also integrated create a highly energy-efficient aerial robot. In this paper, construction concept and software design of the tilt-rotor aerial vehicle GAORI is introduced which uses solar cells and fuel cells as power source. The future work direction and prognosis are discussed.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.4
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• pp.361-366
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• 2015

In this paper, we propose a novel surveillance throwing robot which is compact, light-weight and has an efficient shock absorption mechanism. The throwing robot is designed in a spherical shape to be easily grabbed by a hand for throwing. Also, a motor-wheel linking mechanism is designed to be robustly protected from shocks upon landing. The proposed robot has a weight of 2.2kg and the diameter of its wheels is 150 mm. Through the field experiments, the designed robot is validated to withstand higher than 13Ns of impulse.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.6 s.99
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• pp.718-723
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• 2005

The purpose of this study is to present a fundamental data for evaluating aircraft noise of building site development. By the field experiments and the predicted equal noise level contours using the INM program, actual condition in the building site development arranged district was investigated. In order to get the results, Analysis of factors effected on noise level, sound level on the rate of increase to aircraft demand and difference on the aircraft noise levels according to floor level in apartment house was carried out. As a result the influence of the take-off and landing direction were appeared greatly. The influences of the height at receiving point, movement number of aircraft and increase to aircraft demand were appeared small And the influence of 1 day average WECPNL must be considered.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.996-1000
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• 2003

In this paper, Fly robot with electric power, a kind of Unmanned aerial vehicle (UAV), is considered as an autonomous hovering platform, capable of vertical lift-off, landing and stationary hovering. This aircraft has four rotor and DC motors of electrical Power, which is capable of omni-direction for indoor application. In the earlier days of vertical flight experimentation developers looked at the intuitively easy control functionality of 4 rotor designs. But we need to obtain design method of suitable structures and adequate components because the existing prototypes of 4 rotor-craft don't analyze the propeller, motor characteristic and propose a methodology to optimize this system. In this paper, we will show the new 4 rotor craft with blimp, analyze design and manufacturing method of 4 rotor craft system. Also we prove propriety of our design and manufacturing method by being based on thrust and motor experiment.