• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.5
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• pp.519-525
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• 2010

The finite element (FE) method is generally used to model and simulate the physical behavior of large structures, such as passenger vehicles or aircraft. However, FE analysis involves a very large computation time and cost for developing the analysis model. Therefore, the vibration characteristics of large structural systems are often analyzed using the component mode synthesis (CMS) method, which is one of the substructure synthesis methods. In this study, the vibration characteristics of passenger vehicles are analyzed by using the substructure synthesis method. A passenger vehicle model, which includes a vehicle body, suspension systems, and a sub-frame, is presented. The physical components of the vehicle system are modeled as equivalent substructures using the Craig-Bampton method of CMS. The vibration characteristics, such as the natural frequencies and mode shapes and frequency response, of the vehicle system are determined. The effects of variations in some design parameters on the vibration characteristics of the full vehicle model are also investigated.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.7
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• pp.1-10
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• 2002

Multidisciplinary Design Optimization (MDO) is a new design approach, which aims to reduce the design cycle and the development cost, while improving the performance of the product. In order to develop a framework software where the multidisciplinary design is possible, several methods about the analysis codes integration, the analysis and optimization process management, and the software architecture, are proposed in this study. Centralized DataBase Management System (DBMS) is adopted. Both the Dynamic Link Library(DLL) and the File Interface are suggested and implemented as analysis codes integration methods. To efficiently manage the optimization process and the data flow, the Graphic Programming approach is introduced. The proposed integration methods are verified by two test case examples: Simple house design example and the aircraft wing design problem using three dimensional Panel Code.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.4
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• pp.279-287
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• 2007

The increased availability of portable, low-cost, high resolution video equipments have resulted in a rapid growth of the applications for video sequences. These video devices can be mounted in handhold unit, mobile unit and airborne platforms like maned or unmaned helicopter, plane, airship, etc. This paper describes the feasibility fur generating image map from the experimental results we designed to track the interested points extracted by KLT operator in the neighboring frames and implement image matching for each frames taken from UAV (Unmaned Aerial Vehicle). In the image registration for neighbourhood frames of aerial video, the results demonstrate the successful rate of matching slightly decreases as the drift between frames increases, and also that the stable photographing is more important matching condition than the pixel shift.

• IEMEK Journal of Embedded Systems and Applications
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• v.11 no.1
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• pp.39-46
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• 2016

According to general architecture of flight simulator made up of several independent rendering display systems, display synchronization problem between them naturally happens. In addition, since the flight simulator is usually implemented in the same networks where network delay is not big concern, it is necessary to consider different factors of existing synchronization technique. Among them, in this paper, we propose a new display synchronization scheme for flight simulator where each system has different rendering capacity. In the proposed scheme, each system is synchronized by considering maximum and minimum frames per second (FPS) while considering level of detail and latency. Also, experimental results are given to demonstrate the suitability of the proposed scheme for display synchronization scheme.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.5
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• pp.538-544
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• 2012

In this paper, design optimization of C-frame of a precision drilling and autorivet machine has been performed. The machine, Autoriveter has been developed by Korea Aerospace Industry (KAI), For current autoriveter, it is hard to achieve high efficiency because of heavy weight of the machine. In this paper, we suggest new structure of the current C-frame, a part of autoriveter, by optimization. The result of the study can give much profit for mass-production of the machine.

• Aerospace Engineering and Technology
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• v.11 no.2
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• pp.158-163
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• 2012

Spherical Flying Machine, unlike conventional aircraft structure, is protected by circular frame. This battery-operated propeller machine, which can do vertical take-off and hovering, is under development for indoor and outdoor operation and dubbed as Flying Ball in KARI. In the future, autonomous air vehicle will be constructed for reconnaissance and surveillance application.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.04a
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• pp.760-761
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• 2015

최근에는 아마존 등 해외 배송업체들이 무인항공기(UAV)를 이용한 배송 서비스를 발표하면서 UAV에 관한 관심이 증폭되고 있다. 일반적으로 UAV는 실외에서 GPS 기반으로 이동한다. 하지만, GPS는 오차 법위가 크고 실내에서는 사용하지 못하는 문제가 있다. UAV의 활용을 높이기 위해서는 UAV를 세밀하게 제어하는 방법과 비행 이동을 자율적으로 제어할 때 발생하는 위치의 오차를 보정하는 방법이 필요하다. 위치 오차는 UAV가 비행할 때 부는 바람 등의 이유로 발생한다. 이 논문에서는 UAV의 움직임을 사전에 측정하고 분석한다. 그리고 현재의 위치 오차를 예측하고 보정할 수 있는 방법을 제안한다. 제안한 방법은 Parrot사의 AR.Drone 2.0에 적용해서 처리되는 과정을 소개한다.

• Journal of Advanced Navigation Technology
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• v.24 no.3
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• pp.184-191
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• 2020

Avionics System Integration Laboratory is the integrated test environment for integration and verification of avionics systems. When real equipment can not be used in the laboratory for various reasons, software models should be needed. Because there hasn't been any standardized method for the models so that it is difficult to reuse the developed models, the need for a framework to develop the avionics software models was emerged. We adopted DEVS(discrete event system specification) formalism as the standardized modeling method for the avionics software models. Due to DEVS formalism is based on event-driven algorithm, it doesn't accord a legacy system which has sequential and periodic algorithms. In this paper, we propose real-time event-driven modeling and simulation method for SIL to overcome these restrictions and to maximize reusability of avionics models through the analysis of the characteristics and the limitations of avionics models.

• Journal of the Korea Society of Computer and Information
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• v.20 no.6
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• pp.87-97
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• 2015

An Aerial video summarization is not only the key to effective browsing video within a limited time, but also an embedded cue to efficiently congregative situation awareness acquired by unmanned aerial vehicle. Different with previous works, we utilize sensor operation mode of unmanned aerial vehicle, which is global, local, and focused surveillance mode in order for accurately summarizing the aerial video considering flight and surveillance/reconnaissance environments. In focused mode, we propose the moving-react tracking method which utilizes the partitioning motion vector and spatiotemporal saliency map to detect and track the interest moving object continuously. In our simulation result, the key frames are correctly detected for aerial video summarization according to the sensor operation mode of aerial vehicle and finally, we verify the efficiency of video summarization using the proposed mothed.

• The Journal of Society for e-Business Studies
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• v.16 no.4
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• pp.87-96
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• 2011

The importance of the security management system for the aviation infrastructure cannot be overemphasized. What is especially important on the security management system for it is the assessment that is detaild and systematic. This article presents a framework based on a Hanulcha-type security management system model for a Information security of the Aviation infrastructure. This system checks, estimates and analyzes the goal of security with effect, especially in case of the security-accident on the aviation infrastructure because this system model gives the integrated security assessment method.