• 한국항공운항학회:학술대회논문집
• /
• 2016.05a
• /
• pp.117-124
• /
• 2016

현행 국내 항공안전감독 업무 및 시스템의 인허가 AOC(Air Operator Certificate) 관련 정보 확인 기능 부재, 연 월간 감독계획 간의 연계성 취약, 점검 데이터 활용 통계 및 분석 기반 취약, 점검 및 인허가 대상별 인허가 점검 관련 데이터 관리 기반 미흡, 제한적 시스템 기능 구현에 따른 상당 업무기능의 수작업 문서처리 등의 한계점을 파악하고 이를 개선하기 위한 대안으로 위험관리(Risk Management) 기법을 활용한 항공안전감독 업무절차 및 현행 운영 시스템의 개선모형을 도출하고 이를 적용한 운영체계의 구현 방향성을 제시하고자 한다.

• Journal of Multimedia Information System
• /
• v.2 no.1
• /
• pp.179-186
• /
• 2015

This paper describes the application of a simulated annealing to a random signal-based learning. The simulated annealing is used to generate the reinforcement signal which is used in the random signal-based learning. Random signal-based learning is similar to the reinforcement learning of neural network. It is poor at hill-climbing, whereas simulated annealing has an ability of probabilistic hill-climbing. Therefore, hybridizing a random signal-based learning with the simulated annealing can produce better performance than before. The validity of the proposed algorithm is confirmed by applying it to two different examples. One is finding the minimum of the nonlinear function. And the other is the optimization of fuzzy control rules using inverted pendulum.

• Transactions on Control, Automation and Systems Engineering
• /
• v.1 no.1
• /
• pp.75-86
• /
• 1999

An air-data estimator for generic air-breathing hypersonic vehicles (AHSVs) is developed and demonstrated with an example vehicle configuration. The AHSV air-data estimation strategy emphasized improvement of the angle of attack estimate accuracy to a degree necessitated by the stringent operational requirements of the air-breathing propulsion. the resulting estimation problem involves highly nonlinear diffusion process (propagation); consequently, significant distortion of a posteriori conditional density is suspected. A simulation based statistical analysis tool is developed to characterize the nonlinear diffusion process. The statistical analysis results indicate that the diffusion process preserves the symmetry and unimodality of initial probability density shape state variables, and provide the basis for applicability of an Extended Kalman Filter (EKF). An EKF is designed for the AHSV air-data system and the air data estimation capabilities are demonstrated.

• Journal of the Korea Society of Computer and Information
• /
• v.23 no.4
• /
• pp.51-56
• /
• 2018

This paper proposes the efficient preprocessing method based on curvelet transform for edge enhancement in image. The propose method is generated the edge map by using the Canny algorithm to wavelet transform, which is the sub-step of the curvelet transform. In order to improve the part of edge feature, the selective sharpening according to the generate edge map is applied. In experimental result, the propose method achieves that the enhancement of edge feature is better than conventional methods. This leads that peak to signal noise ratio, edge intensity are improvement on average about 1.92, 1.12dB respectively.

• International Journal of Control, Automation, and Systems
• /
• v.5 no.3
• /
• pp.317-323
• /
• 2007

Quality of Service (QoS) in the Internet depends on queuing and sophisticated scheduling in routers. In this paper, we address the issue of managing traffic flows with different priorities. In our reference model, incoming packets are first classified based on their priority, placed into different queues with different capacities, and then multiplexed onto one router link. The fuzzy nature of the information on Internet traffic makes this problem particularly suited to fuzzy methodologies. We propose a new solution that employs a fuzzy inference system to dynamically and efficiently schedule these priority queues. The fuzzy rules are derived to minimize the selected Lyapunov function. Simulation experiments show that the proposed fuzzy scheduling algorithm outperforms the popular Weighted Round Robin (WRR) queue scheduling mechanism.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.30 no.3
• /
• pp.109-116
• /
• 2022

A modular platform development technique was proposed to minimize development cost and development period by utilizing the already developed unmanned Aerial target AVT, which has been operated and verified for many years. New Mission Profile was designed and structural analysis was performed through finite element analysis (FEA) by analyzing mission requirements for visual short-range, non-visible mid-range, and long-range targets. The targets are used for guided missile anti-aircraft training. In addition, avionics systems including flight control computers for autonomous flights were developed to verify their conformance by performing launcher take-off tests with rapid acceleration changes and autonomous flight tests at a maximum speed of 300km per hour.

• Current Industrial and Technological Trends in Aerospace
• /
• v.8 no.2
• /
• pp.105-112
• /
• 2010

Aircraft accidents are characterized by substantial and extensive damage: the destruction of hulls and the fatalities of passengers. Health and Usage Monitoring Systems (HUMSs) are being developed as a technological approach to prevent the aircraft accident. In Korea, a project to develop HUMS for small airplane is being executed by funding of by Ministry of Land, Transport and Maritime Affairs. In this paper, global R&D trends of HUMS to prevent aircraft accident are described. An on-going Korean HUMS project is also explained, especially for system configuration, functionality and expected achievement.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.26 no.2
• /
• pp.68-75
• /
• 2018

A flare from an Air Force fighter was abnormally dispensed during the landing. To determine the cause of the abnormal dispensing, fracture analysis, signal analysis and reproduction experiments based on physics of failures were performed. The primary cause of the failure was analyzed to be due to an intermittent fault of an internal circuit card in the AN/ALE-40 chaff/flare dispenser by a broken lid of a capacitor, and the root cause which had derived the primary cause was considered to be an improper handling during the domestic maintenance which were changed from the overseas maintenance due to the DMSMS problem. Therefore, the overall process of the maintenance capability development system was reviewed and alternative ways that considers maintenance error decision aid(MEDA) for system improvement were suggested to prevent further failures.

• Journal of Advanced Navigation Technology
• /
• v.20 no.3
• /
• pp.190-195
• /
• 2016

In this paper, Propose to prevent compressor surge and improve the transient response of the fuel flow control system of turbojet engine. Turbojet engine controller is designed by applying Fuzzy-PID control algorithm. To prevent any surge or a flame out event during the engine acceleration or deceleration, the Fuzzy-PID controller effectively controls the fuel flow input of the control system. Fuzzy-PID results are used as the fuel flow control inputs to prevent compressor surge and flame-out for turbo-jet engine and the controller is designed to converge to the desired speed quickly and safely. Using LabVIEW to perform computer simulations verified the performance of the proposed controller. Response characteristics pursuant to the gain were analyzed by simulation.

• Journal of Advanced Navigation Technology
• /
• v.10 no.4
• /
• pp.377-384
• /
• 2006

In this paper the detection time of the distress signal for the satellite-based search and rescue (SAR) system is evaluated. Present LEOSAR system in operation employs a few Low-altitude Earth Orbit (LEO) satellites and hence provides poor and local coverage availability. This results in a considerably long waiting time for a distress beacon to be detected by a rescue mission control center. One can expect that the detection time of the distress signal will be significantly reduced if the proposed MEOSAR system, which is based on the Medium-altitude Earth Orbit (MEO) satellites, is implemented. Taking into account the influence of the obstacles on the beacon signal, simulations are carried out to evaluate the detection time of distress signals for the LEOSAR and MEOSAR systems and the corresponding results are analyzed.