• Title/Summary/Keyword: the dynamic model

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A Study on Determine CONWIP(Constant Work In Process) System Model in the Dynamic Environment (동적환경하에서의 CONWIP(Constant Work In Process) 시스템 모델설정에 관한 연구)

  • 송관배;박재현;강경식
    • Journal of the Korea Safety Management & Science
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    • v.5 no.4
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    • pp.209-217
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    • 2003
  • The traditional Kanban needs a lot of preconditions for fitting conditions of dynamic production processing environment. The traditional Kanban isn't suitable conditions of dynamic production processing environment. Therefore conditions of dynamic production processing environment is needed more stable system. This study is describe CONWIP system such as suitable in dynamic production processing environment. Most Pull system is a Kanban system than use Kanban cards or signal for production management and inventory control. The object of Kanban system is reducing inventory between shop-floor that can reduce inventiry cost. If the system reduce the number of Kanban cards would be reduce the working process WIP, can be reduced and can be found all potential problem of production between shop-floors. This study apply to CONWIP system model for Korean industrial companies.

Optimal Excitation Trajectories for the Dynamic Parameter Identification of Industrial Robots by Using Combined Model (통합모델과 최적 경로설계를 통한 산업용 로봇 동적 매개변수 규명)

  • Park, K.J.
    • Journal of Power System Engineering
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    • v.12 no.2
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    • pp.55-61
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    • 2008
  • This paper discusses the advantages of using Fourier-based periodic excitation and of combining internal and external models in dynamic robot parameter identification. Internal models relate the joint torques or forces with the motion of the robot; external models relate the reaction forces and torques on the bedplate with the motion data. This combined model allows to combine joint torque/force and reaction torque/force measurements in one parameter estimation scheme. This combined model estimation will yield more accurate parameter estimates, and consequently better predictions of actuator torque, which is shown by means of a simulated experiment on a CRS A465 industrial robot.

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Dynamic Model for Ocean Thermal Energy Conversion Plant with Working Fluid of Binary Mixtures

  • Nakamura, Masatoshi;Zhang, Yong;Bai, Ou;Ikegami, Yasuyuki
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.2304-2308
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    • 2003
  • Ocean thermal energy conversion (OTEC) is an effective method of power generation, which has a small impact on the environment and can be utilized semi-permanently. This paper describes a dynamic model for a pilot OTEC plant built by the Institute of Ocean Energy, Saga University, Japan. This plant is based on Uehara cycle, in which binary mixtures of ammonia and water is used as the working fluid. Some simulation results attained by this model and the analysis of the results are presented. The developed computer simulation can be used to actual practice effectively, such as stable control in a steady operation, optimal determination of the plant specifications for a higher thermal efficiency and evaluation of the economic prospects and off-line training for the operators of OTEC plant.

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Quasi-Static and Dynamic Loading Responses of Ti-6Al-4V Titanium Alloy: Experiments and Constitutive Modeling

  • Suh, Yeong-Sung;Akhtar S. Khan
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2003.10a
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    • pp.191-194
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    • 2003
  • The results from a systematic study of the response of a Ti-6Al-4V alloy under quasi-static and dynamic loading at different strain rates and temperatures are presented. It has been shown that the work-hardening rate decreased as the strain rate and the strain increased. The correlations and predictions using modified KHL (Khan-Huang-Liang) viscoplastic constitutive model are compared with those from JC (Johnson-Cook) model and experimental observations. Overall, KHL model correlations and predictions compared much more favorably than the corresponding JC model predictions and correlations.

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A Dynamic Thermal Modeling of Chemical Mechanical Polishing Process (화학기계적 연마 프로세스의 동적 열전달 모델링 연구)

  • Seok, Jong-Won
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.28 no.5
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    • pp.617-623
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    • 2004
  • This paper describes a dynamic thermal model for a representative dual axis rotational Chemical-Mechanical Polishing (CMP) tool. The model is one-dimensional but configured in the two-dimensional space and consists of three sub-models (pad, wafer and slurry fluid), with the first and the second that are time-dependent heat conduction-convection models with linear stationary (wafer) and nonlinear moving (pad) boundary conditions, and the last one that is a heat transport-convection model (slurry fluid). The modeling approach is validated by comparing the simulation results with available experimental data.

A Non-linear Model for Dynamic Analysis of Reactor Internals (원자로내부구조물의 동적해석을 위한 비선형모델)

  • Myung-J.Jhun;Sang-G.Chang;Song, Heuy-G.
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1993.04a
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    • pp.165-172
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    • 1993
  • A non-linear mathematical model has been developed for the dynamic analysis of the reactor internals. The model includes a lumped mass and stiffness with non-linear members such as gap-spring. As hydrodynamic couplings have also been considered in the model, the effect of fluid/structure interaction between internals components due to their immersion in a confining fluid can be studied for the dynamic response analysis. The reactor internals responses for seismic and pipe break excitations have been calculated for the case of with-and without-hydrodynamic couplings.

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Compromise Optimal Design using Control-based Analysis of Hypersonic Vehicles

  • Liu, Yanbin;bing, Hua
    • International Journal of Aeronautical and Space Sciences
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    • v.16 no.2
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    • pp.137-147
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    • 2015
  • Hypersonic vehicles exhibit distinct dynamic and static characteristics, such as unstable dynamics, strict altitude angle limitation, large control bandwidth, and unconventional system sensitivity. In this study, compromise relations between the dynamic features and static performances for hypersonic vehicles are investigated. A compromise optimal design for hypersonic vehicles is discussed. A parametric model for analyzing the dynamic and static characteristics is established, and then the optimal performance indices are provided according to the different design goals. A compromise optimization method to balance the dynamic and static characteristics is also discussed. The feasibility of this method for hypersonic vehicles is demonstrated.

Dynamic Responses of a Slender Offshore Structure Subject to Level Ice Load (平坦氷荷重을 받는 細長形 해양구조물의 動的 거동)

  • Choi, Kyung-Sik
    • Journal of Ocean Engineering and Technology
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    • v.9 no.2
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    • pp.156-166
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    • 1995
  • Regrading the development of offshore natural gas field near Sakhalin Island which is an ice-infested area, this study aims to estimate the dynamic ice load for construction of offshore structures operating in this region. In this paper the design ice load and dynamic responses of a slender Arctic structure upon continuous ice movement are sutdied. Crushing agter a certain elastic deformation is assumed as a primary failure mechanism at the contact zone between semi-infinite level ice edge and the face of structure. Dynamic interaction forces are calculated using a modified Korzhavin's equation and a two-dimensional ice-structure interaction model is adopted. To verify the numerical model, dynamic analysis is performed for on of the Baltic Sea channel markers whose response patterns were presiously observed.

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Computational Modeling of the Bearing Coupling Section of Machine Tools (공작기계 베어링 결합부의 전산 모델링)

  • Kim, Hyun-Myung;Seo, Jae-Wu;Park, Hyung-Wook
    • Journal of the Korean Society for Precision Engineering
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    • v.29 no.10
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    • pp.1050-1055
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    • 2012
  • The bearing coupling section of machine tools is the most important factor to determine their static/dynamic stiffness. To ensure the proper performance of machine tools, the static/dynamic stiffness of the rotating system has to be predicted on the design stage. Various parameters of the bearing coupling section, such as the spring element, node number and preload influence the characteristics of rotating systems. This study focuses on the prediction of the static and dynamic stiffness of the rotating system with the bearing coupling section using the finite element (FE) model. MATRIX 27 in ANSYS has been adopted to describe the bearing coupling section of machine tools because the MATRIX 27 can describe the bearing coupling section close to the real object and is applicable to various machine tools. The FE model of the bearing couple section which has the sixteen node using MATRIX 27 was constructed. Comparisons between finite element method (FEM) predictions and experimental results were performed in terms of the static and dynamic stiffness.

Comparison of Dynamic Characteristics of Spur Gears and Helical Gears (스퍼기어와 헬리컬기어의 동적 특성 비교)

  • Park, Chan-Il;Cho, Do-Hyun
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.22 no.4
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    • pp.358-364
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    • 2012
  • This work dealt with dynamic characteristics of spur gear and helical gear system to understand the gear vibration and noise. To find out dynamic characteristics in the gear system, a finite element model and an analytic model for the gear system were used. Using the models, the natural frequency and mode-shape characteristics of spur gears and helical gears were calculated. Two models show that natural frequencies of helical gears were lower than those of spur gears. Mode-shape characteristics of gear pairs by analytical model and some issues of finite element modeling were also discussed. Impact test was used to validate the finite element model.