• 제목/요약/키워드: Non-linear dynamics

검색결과 259건 처리시간 0.03초

멀티그리드 멀티레벨 기법을 이용한 엔진 밸브 트레인의 동하중 탄성 유체 윤활 유막 해석 (Analysis of Elastohydrodynamic Lubrication Film under Dynamic Loads in Engine Valve Train System with Multigrid Multilevel Method)

  • 장시열
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 1998년도 제28회 추계학술대회
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    • pp.151-159
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    • 1998
  • 디젤 엔진의 푸쉬로드 타입의 밸브 트레인에서의 힘의 전달 과정을 기구학적 응용을 통하여 구하였다. 이러한 힘의 최종 전달 단계인 캠과 평판 종동물의 접촉에서의 작용하중과 상대 운동 속도를 계산하였고 접촉면에서의 유막 두께를 고체면의 탄성변형을 고려하여 계산하였다. 특히 탄성 유체 윤활의 해석을 하는데 있어서 안정성과 수렴성이 우수한 멀티그리드 멀티레벨 기법을 사용하였으며 동하중 상태를 고려하여 유막 두께를 계산하고 기존의 정상상태의 해석해와 비교하였다.

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신경회로망에 의한 로보트 동역학 제어에 관한 연구 (A Study on Dynamic Robot Control by Neural Network)

  • 손종형;한백형
    • 한국통신학회논문지
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    • 제17권9호
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    • pp.1010-1019
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    • 1992
  • As the dynamics model for industrial robot is a mutural coupling of inertia, centrifugal force, gravity, etc it is very difficult to get solution to the question how it works. To control such complex non-linear features of the manipulator, it is required to develop a lot simpler algorithm on the real time.

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MILD SOLUTIONS FOR THE RELATIVISTIC VLASOV-KLEIN-GORDON SYSTEM

  • Xiao, Meixia;Zhang, Xianwen
    • 대한수학회보
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    • 제56권6호
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    • pp.1447-1465
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    • 2019
  • In this paper, the relativistic Vlasov-Klein-Gordon system in one dimension is investigated. This non-linear dynamics system consists of a transport equation for the distribution function combined with Klein-Gordon equation. Without any assumption of continuity or compact support of any initial particle density $f_0$, we prove the existence and uniqueness of the mild solution via the iteration method.

비선형 분석을 이용한 정신활동 상태에 따른 EEG의 변화에 관한 연구 (Some Mental Activity Which Can be Discriminated Only on Non-linear Analysis of EEG Measure)

  • Lee, J.M.;Park, C.J.;Lee, Y.R.;Shin, I.S.;Park, K.S.
    • 대한의용생체공학회:의공학회지
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    • 제22권5호
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    • pp.425-430
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    • 2001
  • 이 연구의 목적은 선형적 주파수 분석방법으로는 구별되지 않는 감정상태와 인지상태의 EEG를 구별할 수 있는 새로운 방법을 제안하는 것이다. 건강한 피험자들의 EEG를 세가지 다른 조건-눈을 감고 편안히 쉬고 있는 상태. 음악을 듣고 있는 상태 눈을 감고 단순한 뺄셈 연산을 수행하고 있는 상태-에서 각각 측정하였다. 점관점 상관타원 (PD2) 방법을 이용하여 각 정신상태에 따른 EEG를 분석하였다. 연산과제를 집중해서 수행했다고 보고한 집단이 그렇지 않다고 보고한 집단보다 더 높은 PD2 값을 통계적으로 유의하게 나타내었다. 또한 음악을 듣는 과제에서 높은 점수를 얻은 집단이 그렇지 않은 집단에 비해 상대적으로 낮은 PD2 값을 나타내었다. 같은 EEG 신호에 선형 분석 방법인 주파수 분석 방법을 적용하여 보았으나, 유의한 차이를 보이지 않았다.

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PTSA 공정의 상세 동적 모사 (Rigorous Dynamic Simulation of PTSA Process)

  • 이혜진;고대호;문일;최대기
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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    • pp.309-309
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    • 2000
  • The main objective of this study is to understand the regeneration step of the PTSA(Pressure and thermal swing adsorption) process below the atmospheric pressure by rigorous dynamic simulation. This target process is to recover toluene using activated carbon as an adsorbent. To do this, the dynamic simulations for the regeneration step are performed at 360, 490, 590mmHg and at high temperature after the simulation of the adsorption step at latm and 298K. A mathematical model was developed to simulate the column dynamics of the adsorption systems. This model is based on non-equilibrium, non-isothermal and non-adiabatic conditions, and axial dispersion and heat conduction are also considered. Heat transfer resistances are considered in gas-solid, gas-column wall and column wall-outside air. The LDF(Linear Driving Force) approximation model describes the mass transfer rate between the gas and solid phase. This study shows that the recovery of toluene by PTSA is more preferable than that by general TSA.

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4륜구동.조향 차량의 선회 성능 해석을 위한 Simulation Tool 개발 (Development of a Simulation Tool for the Cornering Performance Analysis of 4WD/4WS Vehicles)

  • 계경태;김준영;허건수
    • 한국자동차공학회논문집
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    • 제5권1호
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    • pp.195-206
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    • 1997
  • In this study, a simulation tool is developed in order to investigate non steadystate cornering performance of 4WD/4WS vehicles. The 4WD/4WS vehicles are modeled as a 8-th order dynamic system which includes complex non-linear vehicle dynamics and tire models. The vehicle models are constructed into a modulated simulation tool and are utilized for analyzing cornering performance such as combined braking and steering, cornering on the icy read and $\mu$-split braking, The whole analysis is done with the simulation tool which consists of a number of subsystems and offers graphic environment. Simulation results show that this tool is useful and cost-effective in the dynamic analysis of the combustion-engine vehicles as well as electrically driven vehicles.

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회전 및 풍하중 가진 효과를 고려한 대형 풍력발전 로터의 구조 및 진동해석 (Structural and Vibration Analysis of Large Windturbine Rotor Considering the Rotational and Aero Load Effect)

  • 김동만;김동현;박강균;김유성
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2008년도 추계학술대회논문집
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    • pp.270-275
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    • 2008
  • In this study, computer applied engineering (CAE) techniques are full? used to conduct structural and dynamic analyses of a huge composite rotor blade. Computational fluid dynamics is used to predict aerodynamic load of the rotating wind-turbine blade model. Static and dynamic structural analyses are conducted based on the non-linear finite element method for composite laminates and multi-body dynamic simulation tools. Various numerical results for aerodynamic load, dynamic analyses are presented and characteristics of structural behaviors are investigated herein.

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이동구간 예측제어 기법을 이용한 적응 제어기의 전기로 적용 (Application of adaptive controller using receding-horizon predictive control strategy to the electric furnace)

  • 김진환;허욱열
    • 제어로봇시스템학회논문지
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    • 제2권1호
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    • pp.60-66
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    • 1996
  • Model Based Predictive Control(MBPC) has been widely used in predictive control since 80's. GPC[1] which is the superset of many MBPC strategies a popular method, but GPC has some weakness, such as insufficient stability analysis, non-applicability to internally unstable systems. However, CRHPC[2] proposed in 1991 overcomes the above limitations. So we chose RHPC based on CRHPC for electric furnace control. An electric furnace which has nonlinear properties and large time delay is difficult to control by linear controller because it needs nearly perfect modelling and optimal gain in case of PID. As a result, those controls are very time-consuming. In this paper, we applied RHPC with equality constraint to electric furnace. The reults of experiments also include the case of RHPC with monotonic weighting improving the transient response and including unmodelled dynamics. So, This paper proved the practical aspect of RHPC for real processes.

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$Nos\acute{e}-Poincar\acute{e}$ 분자 동역학 알고리즘을 이용한 나노 와이어의 역학적 거동 해석 (Analysis of Mechanical Behavior of Nanowire by $Nos\acute{e}-Poincar\acute{e}$ Molecular Dynamics Simulation)

  • 이병용;조맹효
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회A
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    • pp.506-511
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    • 2007
  • Mechanical behavior of copper nanowire is investigated. An FCC nanowire model composed of 1,408 atoms is used for MD simulation. Simulations are performed within NVT ensemble setting without periodic boundary conditions. $Nos\acute{e}-Poincar\acute{e}$ MD algorithm is employed to guarantee preservation of Hamiltonian and temperature. Numerical tensile tests of Nanowire are carried out with constant strain rate. Additionally, temperature and strain rate effects are considered. Stress-strain curve is constructed from the calculated Cauchy stresses and specified strain values. In (22,4,4) Copper nanowire, non-linear behavior appears around ${\epsilon}\simeq0.09.$ At this instance, starting of structural reorientations are observed. At the onset of reorientation, the modulus characteristics are also investigated.

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