• Title/Summary/Keyword: Moving Accuracy

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A dynamic foundation model for the analysis of plates on foundation to a moving oscillator

  • Nguyen, Phuoc T.;Pham, Trung D.;Hoang, Hoa P.
    • Structural Engineering and Mechanics
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    • v.59 no.6
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    • pp.1019-1035
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    • 2016
  • This paper proposes a new foundation model called "Dynamic foundation model" for the dynamic analysis of plates on foundation subjected to a moving oscillator. This model includes a linear elastic spring, shear layer, viscous damping and the special effects of mass density parameters of foundation during vibration. By using finite element method and the principle of dynamic balance, the governing equation of motion of the plate travelled by the oscillator is derived and solved by the Newmark's time integration procedure. The accuracy of the algorithm is verified by comparing the numerical results with the other numerical results in the literature. Also, the effects of mass and damping ratio of system components, stiffness of suspension system, velocity of moving oscillator, and dynamic foundation parameters on dynamic responses are investigated. A very important role of these factors will be shown in the dynamic behavior of the plate.

IMMERSED BOUNDARY METHOD FOR COMPRESSIBLE VISCOUS FLOW AROUND MOVING BODIES (이동하는 물체 주위의 압축성 유동에 대한 가상경계법)

  • Cho, Yong;Chopra, Jogesh;Morris, Philip J.
    • 한국전산유체공학회:학술대회논문집
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    • 2007.10a
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    • pp.200-208
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    • 2007
  • A methodology for the simulation of compressible high Reynolds number flow over rigid and moving bodies on a structured Cartesian grid is described in this paper. The approach is based on a modified version of the Brinkman Penalization method. To avoid oscillations in the vicinity of the body and to simulate shcok-containing flows, a Weighted Essentially Non-Oscillatory scheme is used to discretize the spatial flux derivatives. For high Reynolds number viscous flow, two turbulence models of the two-equation Menter's SST URANS model and a two-equation Detached Eddy Simulation are implemented. Some simple flow examples are given to assess the accuracy of the technique. Finally, a moving grid capability is demonstrated.

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Fault Detection in the Semiconductor Etch Process Using the Seasonal Autoregressive Integrated Moving Average Modeling

  • Arshad, Muhammad Zeeshan;Nawaz, Javeria Muhammad;Hong, Sang Jeen
    • Journal of Information Processing Systems
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    • v.10 no.3
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    • pp.429-442
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    • 2014
  • In this paper, we investigated the use of seasonal autoregressive integrated moving average (SARIMA) time series models for fault detection in semiconductor etch equipment data. The derivative dynamic time warping algorithm was employed for the synchronization of data. The models were generated using a set of data from healthy runs, and the established models were compared with the experimental runs to find the faulty runs. It has been shown that the SARIMA modeling for this data can detect faults in the etch tool data from the semiconductor industry with an accuracy of 80% and 90% using the parameter-wise error computation and the step-wise error computation, respectively. We found that SARIMA is useful to detect incipient faults in semiconductor fabrication.

A Moving Least Squares weighting function for the Element-free Galerkin Method which almost fulfills essential boundary conditions

  • Most, Thomas;Bucher, Christian
    • Structural Engineering and Mechanics
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    • v.21 no.3
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    • pp.315-332
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    • 2005
  • The Element-free Galerkin Method has become a very popular tool for the simulation of mechanical problems with moving boundaries. The internally applied Moving Least Squares interpolation uses in general Gaussian or cubic weighting functions and has compact support. Due to the approximative character of this interpolation the obtained shape functions do not fulfill the interpolation conditions, which causes additional numerical effort for the application of the boundary conditions. In this paper a new weighting function is presented, which was designed for meshless shape functions to fulfill these essential conditions with very high accuracy without any additional effort. Furthermore this interpolation gives much more stable results for varying size of the influence radius and for strongly distorted nodal arrangements than existing weighting function types.

Dynamics of an Axially Moving Bernoulli-Euler Beam : Variational Method-Based Spectral Element Modeling (변분법을 이용한 축방향으로 움직이는 보의 스펙트럴 요소 모델링)

  • Choi, Jung-Sik;Lee, U-Sik
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.831-834
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    • 2008
  • The spectral element model is known to provide very accurate structural dynamic characteristics, while reducing the number of degree-of-freedom to resolve the computational and cost problems. Thus, the spectral element model with variational method for an axially moving Bernoulli-Euler beam subjected to axial tension is developed in the present paper. The high accuracy of the spectral element model is the verified by comparing its solutions with the conventional finite element solutions and exact analytical solutions. The effects of the moving speed and axial tension the vibration characteristics, wave characteristics, and the static and dynamic stabilities of a moving beam are investigated.

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Spectral Element Modeling for the Axially Moving Strings (축방향으로 이동하는 현에 대한 스펙트럴 요소 모델링)

  • Choi, Jung-Sik;Lee, U-Sik
    • Proceedings of the KSR Conference
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    • 2009.05a
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    • pp.1092-1096
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    • 2009
  • The spectral element modeling is known to provide very accurate structural dynamic characteristics, while reducing the number of degree-of-freedom to resolve the computational and cost problems. Thus, the spectral element model with variational method for an axially moving string subjected to axial tension is developed in the present paper. The high accuracy of the spectral element model is the verified by comparing its solutions with the conventional finite element solutions and exact analytical solutions. The effects of the moving speed and axial tension the vibration characteristics, wave characteristics, and the static and dynamic stabilities of a moving string are investigated.

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Dynamics of a bridge beam under a stream of moving elements -Part 1 - Modelling and numerical integration

  • Podworna, M.
    • Structural Engineering and Mechanics
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    • v.38 no.3
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    • pp.283-300
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    • 2011
  • A new conception of fundamental tasks in dynamics of the bridge-track-train systems (BTT), with the aim to evaluate moving load's models adequacy, has been developed. The 2D physical models of BTT systems, corresponding to the fundamental tasks, have been worked out taking into account one-way constraints between the moving unsprung masses and the track. A method for deriving the implicit equations of motion, governing vibrations of BTT systems' models, as well as algorithms for numerical integration of these equations, leading to the solutions of high accuracy and relatively short times of simulations, have been also developed. The derived equations and formulated algorithms constitute the basis for numerical simulation of vibrations of the considered systems.

The Detection of Lanes and Obstacles in Real Time Using Optimal Moving Window

  • Park, Sung-Yug;Ju, Jae-Yul;Lee, Jang-Myung
    • Proceedings of the IEEK Conference
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    • 2000.07b
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    • pp.889-893
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    • 2000
  • In this paper, a method to detect lanes and obstacles from the images captured by a CCD camera fitted in an automobile is proposed, and a new terminology “Moving Window” is defined. Processing the input dynamic images in real time can cause quite a few constraints in terms of hardware. In order to overcome these problems and detect lanes and obstacles in real time using the images, the optimal size of “Moving Window” is determined, based upon road conditions and automobile states. The real time detection is made possible through the technique. For each image frame, the moving window is moved in a predicted direction, the accuracy of which is improved by the Kalman filter estimation. The feasibility of the proposed algorithm is demonstrated through the simulated experiments of freeway driving.

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Restoration of Realtime Three-Dimension Positions Using PSD Sensor (PSD센서를 이용한 실시간 3차원 위치의 복원)

  • Choi, Hun-Il;Jo, Yong-Jun;Ryu, Young-Kee
    • Proceedings of the KIEE Conference
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    • 2003.11c
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    • pp.507-510
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    • 2003
  • In this paper, optical sensor system using PSD(Position Sensitive Detection) is proposed to obtain the three dimensional position of moving markers attached to human body. To find the coordinates of an moving marrer with stereo vision system, two different sight rays of an moving marker are required. Usually, those are acquired with two optical sensors synchronized at the same time. PSD sensor is used to measure the position of an incidence light in real-time. To get the three-dimension position of light source on moving markers, a conventional camera calibration method are used. In this research, we realized a low cost motion capture system. The proposed system shows high three-dimension measurement accuracy and fast sampling frequency.

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Multiple Properties-Based Moving Object Detection Algorithm

  • Zhou, Changjian;Xing, Jinge;Liu, Haibo
    • Journal of Information Processing Systems
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    • v.17 no.1
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    • pp.124-135
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    • 2021
  • Object detection is a fundamental yet challenging task in computer vision that plays an important role in object recognition, tracking, scene analysis and understanding. This paper aims to propose a multiproperty fusion algorithm for moving object detection. First, we build a scale-invariant feature transform (SIFT) vector field and analyze vectors in the SIFT vector field to divide vectors in the SIFT vector field into different classes. Second, the distance of each class is calculated by dispersion analysis. Next, the target and contour can be extracted, and then we segment the different images, reversal process and carry on morphological processing, the moving objects can be detected. The experimental results have good stability, accuracy and efficiency.