• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2002.09a
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• pp.364-370
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• 2002

본 논문에서는 양자물리학 분야에서 Lanczos 방법의 수렴을 가속화하기 위해 개발된 바 있는 행렬의 거듭제곱 기법을 동역학 분야의 Lanczos 순환식에 도입함으로써 구조물의 고유치 해석의 효율성을 향상시켰다 행렬의 거듭제곱 기법을 도입한 Lanczos 방법이 기존의 방법보다 수렴성이 더욱 우수하다. 수치예제를 통해 행렬의 거듭제곱 기법을 도입한 Lanczos 방법의 효율성을 검증하였으며 제안방법을 통한 고유치 해석에 있어서 가장 적합한 거듭제곱값을 제시하였다.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.1
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• pp.110-123
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• 2000

In this Study, the dynamic equation for vibration analysis of mechanical systems with kinematic constraints is derived. This equations are derived in terms of small displacements of Cartesian coordinates, and are applied to compute the dynamic response and the natural modes of the suspension system of a vehicle. The results are validated through the comparison with the results from conventional nonlinear dynamic analysis and modal test.

• Proceedings of the KAIS Fall Conference
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• 2010.05b
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• pp.1153-1155
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• 2010

본 논문에서는 무인정찰기 카메라의 진동에 대한 해석을 동역학 해석 프로그램 ADAMS를 통하여 수행하였다. 정찰시 카메라에 진동이 발생할 경우 시선 불안정화에 의해 정확한 촬영이 불가하다. 이에 진동을 감소시키기 위한 방진구의 최적화를 위하여 정적 처짐량 및 비행기의 운행에 따른 진동에 대한 해석으로 sine sweep, RMS white noise에 대한 해석을 수행하고자 한다.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.179-182
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• 2010

본 연구에서는 MLS 차분법을 이용하여 동역학 문제를 해석하기 위한 explicit 동적해석 알고리즘을 제시한다. 격자망이 없는 장점을 부각시키기 위해 이동최소제곱법에 근거한 Taylor 전개로부터 미분근사를 얻고 차분식을 구성했다. 지배 미분방정식의 시간항을 CDM(Central difference Method) 차분하여 빠른 속도로 동적해석을 수행하였다. 수치결과를 통해 본 연구에서 제시한 알고리즘의 정확성과 안정성을 확인할 수 있었다.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2280-2282
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• 2001

EMV(electromagnetic valve) 시스템은 자동차에서 기계식 캠을 사용하지 않고 전자기력을 이용하여 흡·배기 밸브를 작동시키고 타이밍을 조절하기 위한 것이다. 본 논문에서는 EMV 시스템을 위한 전자기와 기계적 모델을 사용하여 그에 대한 동역학 모델을 유도하였다. EMV 시스템의 최대 동작주파수가 가솔린 엔진의 최대 회전수 6000rpm에 대응한 valve의 주파수가 50Hz 되기 위한 제어기를 설계하였고, 실험을 통하여 문제점들을 파악하고자 한다.

• Proceedings of the KSEEG Conference
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• 2007.04a
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• pp.313-315
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• 2007

• Journal of Aerospace System Engineering
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• v.15 no.3
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• pp.99-104
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• 2021

The characteristics of wind sensors were experimentally analyzed and compared for purposes of application in multicopter type drones. For rotating wind sensors, the dynamics effect causes measurement errors, while manufacturing errors and signal processing errors were found to constitute significant errors in ultrasonic sensors. In the ultrasonic sensor, the errors decrease as the distance of the transducer increases. These characteristics were experimentally confirmed, and it was established that ultrasonic sensors capable of outputting voltage or data of 10 Hz or more are suitable for use in multicopters.

• Composites Research
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• v.24 no.2
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• pp.14-21
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• 2011

In this paper, a dynamic model is proposed for multi-axis optical structure of an aircraft. Modal analysis, sine-wave analysis, and random vibration analysis are done using a multi-body dynamic program for the multi-axis optical structure. By applying Al 6061-T6 and two types of CFRP to the camera module, x, y, and z responses are found and compared according to each axis excitation. The results will be used for reducing the weight of the camera module.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.4
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• pp.8-15
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• 2013

Recently many kinds of electric vehicles have been developed as many governments demand the environmental friendly vehicles. In this paper, study of load optimization for the electric vehicle which has multiple axle power system was conducted. For the analysis of the vehicle which has three or four driving axles, a method based on the geometry and assumptions that considering axles as a spring model and normal forces of the axles are proportional to the displacement of the axles was applied with basic vehicle dynamics. With the developed vehicle analysis technique, algorithm to find the optimal motor operating points was developed. Using this algorithm, it was possible to find the optimization of vehicle load distribution for multiple axles according to the driving cycles. Also, control logic for the vehicle can be developed based on the optimization simulation results.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.11
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• pp.919-925
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• 2016

In this study, multibody dynamic and mechanical analyses were conducted for the structure of roller chain bucket elevator system. The fatigue life of the roller chain elevator system was determined under static and fatigue loadings. Results of multibody dynamic analysis suggested that the maximum contact force occurred at the drive sprocket engagement point with the roller chain due to maximum tension. Fatigue analysis results suggest that the high load roller chain system is durable and safe because its life time is more than 700,000 cycles, close to its designed value (1,000,000 cycle). However, the contact portion of plate and pin needed a safety factor. The dynamic analysis of the heavy load roller chain was conducted with a multibody dynamic analysis program. The results obtained in this study can be utilized for dynamic analysis of roller chain systems in all industries.