• International Journal of Aeronautical and Space Sciences
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• 제2권1호
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• pp.28-43
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• 2001

Developed in these two series of paper is a complex dynamic model representing the motion of aircraft on the ground and a computer program for numerical simulation. The first part of paper presents the theoretical derivation of equations of motion of the landing gear system based on the physical principle. Developed model is 'structured' in the sense that the undercarriage system is regarded as an assembly of strut, tire, and wheel, where each component is modeled by a separate module. These modules are linked with two external modules-the aircraft and the runway characteristics-to carry out dynamic analysis and numerical simulation of the aircraft motion on the ground. Three sets of coordinate system associated with strut, wheel/tire and runway are defined, and external loads to each component and response characteristics are examined. Lagrangian formulation is used to derive the undercarriage equations of motion relative to the moving aircraft, and the resultant forces and moments from the undercarriage are transformed to aircraft body axes.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.2560-2565
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• 2003

The paper presented here covers the work associated with the flight control law design, ground based and in flight simulation and handling qualities assessment of the Fly-by-Wire type Aircraft (FBWA). The control law was designed for the most unstable aircraft configuration flight regime for the target aircraft (FBWA). The ground based simulation including math-model, real-time pilot-in-the-loop and iron bird simulation were used for validation of the control law before the experimental in-flight simulation on the IFS (In.Flight-Simulator) aircraft. The flight tests results showed that Level 1 handling qualities for the most unstable flight regime were achieved.

• 제어로봇시스템학회논문지
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• 제18권5호
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• pp.433-438
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• 2012

In this paper, a operation network system equipped with onboard wireless communication systems and ground-based mission control systems is proposed for swarm flight of small UAVs. This operating system can be divided into two networks, UAV communication network and ground control system. The UAV communication network is intend to exchange the informations of navigation, mission and flight status with minimum time delay. The ground control system consisted of mission control systems and UDP network. Proposed operation network system can make a swarm flight of various UAVs, execute complex missions decentralizing mission to several UAVs and cooperte several missions. Finally, PILS environments are developed based on the total operating system.

• 한국군사과학기술학회지
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• 제14권3호
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• pp.353-358
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• 2011

In this paper, we have introduced a Missile In the Loop Simulation(MILS) Software developed for the missile ground test, which is based on a commercial hard real-time operating system(OS) on Windows platform called as Real-Time eXtension(RTX). MILS software makes it possible to test overall system functions of a integrated missile on the ground in the flight conditions by real-time imitating its inertial data. By means of MILS, we have performed missiles ground tests, which result in successful real flight tests.

• 한국신뢰성학회지:신뢰성응용연구
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• 제15권2호
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• pp.131-138
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• 2015

In modern warfare, the number of unmanned systems grow faster than any other weapon systems. Therefore, it is very important to predict and measure the combat effectiveness (CE) of unmanned weapon systems in battlefield for deciding defense budget to acquire those systems. In general, quantitative calculation of weapon effectiveness under complicated battlefield is difficult based on the future network centric warfare. Hence, many papers studied how to measure the combat effectiveness and tried to study a lot of related issues about it. However, there are few papers dealing with the relationship between the UGV (Unmanned Ground Vehicle)'s performance and CE in a ground battlefield. In this paper, we do the sensitivity analysis based on a given scenario in a small unit battle. In order to do that, we developed simulation model using AnyLogic and changed the input parameters such as detection and hitting probabilities. We also assess the simulation outputs according to the variation of input parameters. The MOE used in this simulation model output is survival ratio for Blue force. We hope that this paper will be useful to find which input variable is more effective to increase combat effectiveness in a small unit ground battlefield.

• 한국전산유체공학회지
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• 제15권4호
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• pp.53-59
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• 2010

Preliminary design of a ground plate, a device installed close to the aircraft model for wind tunnel test to simulate the ground effect, was performed by a numerical simulation. A two-dimensional numerical study was performed initially to decide the optimal leading edge and flap configurations. Then, three-dimensional studies were conducted to decide the optimal flap deflection angle for pressure distribution reduction since the plate and the plate supporting system generate static pressure difference between the upper and lower flow regions. Three-dimensional simulation additionally studied the effect of the clearance between the plate and the wind tunnel side wall. For the efficiency of computation, half model was simulated and a symmetric boundary condition was applied on the center plane. Based on the preliminary design, a ground plate was designed, manufactured and tested at the Korea Aerospace Research Institute(KARI) wind tunnel. The measured pressure differences versus flap deflection angle agreed well with the predicted results.

• Journal of Astronomy and Space Sciences
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• 제30권4호
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• pp.279-290
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• 2013

Due to the continuous space development by mankind, the number of space objects including space debris in orbits around the Earth has increased, and accordingly, difficulties of space development and activities are expected in the near future. In this study, among the stages for space debris removal, the implementation of a vision-based approach technique for approaching space debris from a far-range rendezvous state to a proximity state, and the ground test performance results were described. For the vision-based object tracking, the CAM-shift algorithm with high speed and strong performance, and the Kalman filter were combined and utilized. For measuring the distance to a tracking object, a stereo camera was used. For the construction of a low-cost space environment simulation test bed, a sun simulator was used, and in the case of the platform for approaching, a two-dimensional mobile robot was used. The tracking status was examined while changing the position of the sun simulator, and the results indicated that the CAM-shift showed a tracking rate of about 87% and the relative distance could be measured down to 0.9 m. In addition, considerations for future space environment simulation tests were proposed.

• 한국지진공학회논문집
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• 제28권5호
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• pp.233-247
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• 2024

The damage to structures during an earthquake can be varied depending on the frequency characteristics of seismic waves and the geological properties of the ground. Therefore, considering such attributes in the design ground motions is crucial. The Korean seismic design standard (KDS 17 10 00) provides design response spectra for various ground classifications. If required for time-domain analysis, ground motion time series can be either selected and adjusted from motions recorded at rock sites in intraplate regions or artificially synthesized. Ground motion time series at soil sites should be obtained from site response analysis. However, in practice, selecting suitable ground motion records is challenging due to the overall lack of large earthquakes in intraplate regions, and artificially synthesized time series often leads to unrealistic responses of structures. As an alternative approach, this study provides a case study of generating ground motion time series based on the hybrid broadband ground motion simulation of selected scenario earthquakes at sites in the Nakdonggang delta region. This research is significant as it provides a novel method for generating ground motion time series that can be used in seismic design and response analysis. For large-magnitude earthquake scenarios close to the epicenter, the simulated response spectra surpassed the 1000-year design response spectra in some specific frequency ranges. Subsequently, the acceleration time series at each location were used as input motions to perform nonlinear 1D site response analysis through the PySeismoSoil Package to account for the site response characteristics at each location. The results of the study revealed a tendency to amplify ground motion in the mid to long-period range in most places within the study area. Additionally, significant amplification in the short-period range was observed in some locations characterized by a thin soil layer and relatively high shear wave velocity soil near the upper bedrock.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 추계학술대회 논문집 전력기술부문
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• pp.285-287
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• 2007

This paper describes that the effect on the other system is generated by the single line to ground fault of the underground transmission systems and distribution systems established the common ground in trefoil. Each system is modeled by EMTP/ATPDraw and the system carry out simulations according to the various values of common ground to analyse. In this study, the result of analysis based on simulation suggests protection method and ground system of each system.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.353-364
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• 2011

This paper presents the ground behaviour of shield TBM lunching area during excavation. In order to perform this study, a scaled model test was carried out in the 1/45 scale for a field tunnel in practice where the tunnel had about 7.8 m diameter at Seoul Metro Line 9 construction site. The test to simulate earth pressure balance (EPB) shield TBM tunnelling at the lunching area was conducted with the developed small scaled shield TBM machine. Measurements were performed during simulation of excavation for total jacking thrust force, ground displacements and pressures. Based on the analysis of simulation results, the stability of ground was verified and evaluated. In particular, the suitable reinforcement range and methods are also suggested. In addition, these results are useful for engineers and technicians to select suitable and serviceable machine operation parameters and reduce environmental influence at all stages of tunnel construction.