• 항공우주시스템공학회지
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• 제16권4호
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• pp.45-52
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• 2022

최근 차세대 운송시스템으로 주목받고 있는 UAM 분야에서 무인항공기 활용을 위한 기술 개발이 활발히 진행되고 있다. 이러한 기술이 적용된 무인항공기는 주로 도심에서 운용되기 때문에 추락사고를 예방하는 것이 중요하다. 그러나 충돌이 발생되는 무인항공기는 비선형성이 강하기 때문에 비정상 비행상태를 예측하는 것은 쉽지 않은 일이다. 본 논문에서는 CNN-LSTM 혼합모델을 이용하여 무인항공기의 비행상태를 예측하는 방법을 제안한다. 제안 모델은 비행 데이터간의 시간적, 공간적 특징을 추출하는 CNN 모델과 추출된 특징의 장단기 시간 의존성을 추출하는 LSTM 모델을 결합하여 미래의 특정 시점에서 비행 상태변수를 예측한다. 모의 실험은 제안하는 방법이 기존 인공신경망 모델에 기반한 예측 방법보다 우수한 성능을 보인다.

• 한국항공운항학회지
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• 제22권3호
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• pp.24-32
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• 2014

Due to the rapid growth of domestic and overseas airline markets, the demand for airline pilots has also been growing fast. Meeting such a market needs, central government, Ministry of Land and Transportation has set up civil airline pilot training center at Ulgin airport to train and provide the market with commercial airline pilots. Not only central government but universities in Korea also have tried to train pilots by operating flight training academies. Even though there are more than a dozen of flight training centers including colleges and private academies, there have been less efforts to measure and evaluate the effectiveness of the flight training school's curriculums compared to other scholar majors in a university. Therefore this paper tried to evaluate the educational effectiveness of the curriculums using the Kirk-Patrick measurement model, which has been regarded as one of the most popular and accurate measurement tool for an empirical research in social science. According to the empirical research, it was found out the inter-personal relationship between an instructor pilot and flight trainee was perceived as the most important factor to have an impact on learning abilities and student's behaviors.

• International Journal of Railway
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• 제4권4호
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• pp.109-115
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• 2011

An analysis and design method for reducing aerodynamic noise in high-speed trains based on biomimetics of noiseless flight of owl is proposed. Five factors related to the morphology of the flight feather have been selected, and the candidate optimal shape of the flight feather is determined. The turbulent flow field analysis demonstrates that the optimal shape leads to diminished vortex formation by causing separation of the flow as well as allowing the fluid to climb up along the surface of the flight feather. To determine the effect of scaling of the owl's flight feather on the noise reduction, a two-fold and a four-fold scaled up model of the feather are constructed, and the numerical simulations are carried out to obtain the aerodynamic noise levels for each scale. Original model is found to reduce the noise level by 10 dBA, while two-fold increase in length dimensions reduces the noise by 12 dBA. Validation of numerical solution using wind tunnel experimental measurements is presented as well.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 1999년도 추계학술대회
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• pp.53-72
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• 1999

IPQC system was introduced for the flight safety at the age of scientific safety management in the 1980s. In spite of performing this system, aircraft accidents caused by human factors, which were above 70% among all flight accident factors, have not been reduced. Accordingly, throughout this paper I analyzed the aircraft accident factors by means of a literature study and a pilot survey. Then, based on the notion of TQC(Total Quality Control), I hierarchically classified Individual Quality into Capacity Management, Safety Management, and General Management and did the low-ranked management factors as well. AHP (Analytic Hierarchy Process), one of the scientific management methods, was used for estimating the relative importance of Individual Quality Control factors and the heavy aircraft accident causes over the last 20 years were analyzed according to the flight ranks. Based on the comparative analysis of results derived above, an IPQC model as flight ranks is established. In short, according to this newly suggested model we can obtain the maximum flight safety with the preventive actions against aircraft accidents caused by human factors and by improving the operation effect under the reasonable pilot management.

• 한국군사과학기술학회지
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• 제25권6호
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• pp.596-605
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• 2022

In this study, analysis of dynamic characteristics and flight vibration was performed to unmanned aerial vehicles. The analysis model was supplemented by performing a dynamic characteristic test and a random vibration test using manufactured dummy aerial vehicle. For the dynamic characteristic test, a bungee cable was used to implement the free end boundary condition. Prior to the flight vibration test using a multiple electric shaker, a random vibration test was performed to predict the excitation force during the actual flight vibration test. It was judged that the actual test could be predicted more accurately by supplementing the analysis model from the test results. In addition, it was possible to determine the feasibility of the test by predicting the excitation force of the flight vibration test.

• 한국정보전자통신기술학회논문지
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• 제16권6호
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• pp.472-477
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• 2023

본 논문에서는 쿼드콥터 드론이 동적인 외부 환경 아래서도 외란에서도 효과적으로 경로를 추종하고 비행 안전성을 유지할 수 있도록 모델 예측 제어(MPC) 기법을 제안한다. MATLAB/Simulink에서 수행된 시뮬레이션을 통해, 외란이 주어지는 비행 시나리오에서 PID와 MPC 두 제어기의 성능을 비교한다. 제안된 설계 방법으로 MPC 제어기가 압력 변화와 공기 밀도 변동과 같은 외란에 대하여 MPC와 PID 제어기의 성능을 비교했을 때에 쿼드콥터 드론의 입력받은 주행 경로와 실제 경로의 Mean Squared Error 수치가 외란을 주기 전에는 0.2의 성능 차이를 보였다. 그리고, 외란을 주었을 때에는 0.8을 차이를 보이며 MPC 제어기의 향상된 경로 추종 정확도를 보여준다.

• 제어로봇시스템학회논문지
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• 제13권10호
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• pp.927-932
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• 2007

The sophisticated mathematical model is required for the design and the database construction of the advanced flight control system of UAV. In this paper, flight test of KARI's research UAV, often called DURUMI-II, is implemented for the data acquisition from the maneuver flight. The flight path reconstruction is implemented to ensure that the measured data is consistent and error free. The nonlinear system identification for the refined mathematical modeling is implemented with the verified measurements from the flight path reconstruction. The simulation with the identified results have a good validation when the simulated responses were compared to the flight tested data.

• 한국항공운항학회지
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• 제18권4호
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• pp.21-29
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• 2010

The main purpose of this study is to obtain linear models for the design of automatic flight controller in order to operate the Light Sport Aircraft as unmanned air vehicle. Flight test equipments installed on the aircraft to acquire flight test data are described and maneuvers for practical speed calibration are introduced. Parameters for the linear models of lateral and longitudinal motion are estimated by the Output error method as well as trim data analysis using the flight test data. Simulated data using the estimated parameters is shown to agree well with the measurement data. Estimated parameters obtained for several flight conditions can be used to improve the aerodynamic database of the simulation program.

• Journal of Positioning, Navigation, and Timing
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• 제11권2호
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• pp.109-117
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• 2022

This paper proposes a method for detecting flight anomalies of drones through the difference between the command of flight controller (FC) and the navigation solution. If the drones make a flight normally, control errors generated by the difference between the desired control command of FC and the navigation solution should converge to zero. However, there is a risk of sudden change or divergence of control errors when the FC control feedback loop preset for the normal flight encounters interferences such as strong winds or navigation sensor abnormalities. In this paper, we propose the method with a deep neural network model that predicts the control error in the normal flight so that the abnormal flight state can be detected. The performance of proposed method was evaluated using the real-world flight data. The results showed that the method effectively detects anomalies in various situation.

• 한국항공운항학회:학술대회논문집
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• 한국항공운항학회 2016년도 춘계학술대회
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• pp.269-275
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• 2016

This paper considers the arrival, airport and departure capacity as a whole, through which, the network effect between airports is fully emphasized, the flight action is coordinated, and the flight demand pattern is reasonably assigned. The optimization problem of flight queues in multi-airport is studied in detail; the mathematical model of multi-airport opening non-real time flow management in terminal area is established, and related problems such as the parameters, the simplification and the solving of the model are discussed in detail to some extent. Appropriate decision making variables are taken to make the multi-airport network system linear 0-1 integer programming model, thus, the solving of the model is available and the central flow management is realized. The heuristic implicit enumeration presented in this paper can effectively solve this kind of problems. Through the simulation of some airports network system, we not only validate the algorithm presented in this paper, but also give a deep analysis of the results, which would produce reference for later practicable use. The simulation proves that this algorithm offers a good way to settle the problem of multi-airport flight queue optimization in air traffic management automation system in terminal area.