• Title/Summary/Keyword: interpolations

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Development of CNC controller based on i80486 and 32bit DSP chip (i80486과 32비트 DSP를 사용한 CNC 제어기의 개발)

  • Kim, Dong-Il;Song, Jin-Il;Kim, Sung-Kwan;Lee, Choong-Hwan;Lee, Yun-Suk;Kang, Moon;Na, Sang-Keun;Lim, Yong-Gyu;Nam, Ki-Jun
    • 제어로봇시스템학회:학술대회논문집
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    • 1992.10a
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    • pp.537-540
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    • 1992
  • This paper presents Samsung CNC (Computer Numerical Controller) system with an intel 80486/487 as the main CPU and a 32 bit floating point DSP(Digital Signal Processor) TMS320C30 as the motion control CPU. The Samsung CNC system diverse user-frienly characteristics such as multi-tasking, powerful menu system, internal PLC system, and 2/3 dimensional graphics in wire and solid mode. The main CPU executes central processing program, user interface program, interpreter, BMI, etc while the motion control CPU carries out some interpolations, acceleration/deceleration, and PID control algorithm with feedforward terms. Complex interpolations except linear and circular ones are performed on the main control CPU. The experimental results for the circular interpolation under linear acceleration/deceleration shows that the proposed CNC system can be widely used in controlling machining centers with good machining accuracy.

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NUMERICAL STUDY OF AN EXTERNAL STORE RELEASED FROM A FIGHTER AIRCRAFT

  • Yoon, Young-Hyun;Cho, Hwan-Kee;Chung, H.S.;Lee, S.H.;Han, C.H.
    • Journal of computational fluids engineering
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    • v.13 no.4
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    • pp.80-85
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    • 2008
  • The prediction of the separation trajectories of external stores released from a military aircraft is an important task in the aircraft design area having the objective to define the operational and release envelopes. This paper presents the results obtained for store separation by employing commercial softwares, FLUENT and CFD-FASTRAN. FLUENT treats the rigid body motion by employing a remeshing scheme. CFD-FASTRAN uses Chimera(overset) grid and interpolations. It was found that, for the prediction of the trajectories and behavior of the stores separated from the wing, both codes show the good agreement with the experimental results.

Graphic Representation of Solutions of Partial Differential Equations Using their Corresponding Fuzzy Systems

  • 문병수
    • Proceedings of the Korean Society of Computational and Applied Mathematics Conference
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    • 2003.09a
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    • pp.4.2-4
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    • 2003
  • In this paper, we describe how to approximate the solutions of partial differential equations by bicubic spline functions whose interpolation errors at non-grid points are smaller in general than those by linear interpolations of the original solution at grid points. We show that the bicubic spline function can be represented exactly or approximately by a fuzzy system, and that the resulting fuzzy rule table shows the contours of the solution function. Thus, the fuzzy rule table is identified as a digital image and the contours in the rule table provide approximate contours of the solution of partial differential equations. Several illustrative examples are included.

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APPLICATION OF MOVING LEAST SQUARE METHOD IN CHIMERA GRID METHOD (중첩격자에 대한 이동최소자승법 적용 연구)

  • Lee, K.;Lee, S.;Cho, J.Y.
    • Journal of computational fluids engineering
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    • v.13 no.1
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    • pp.49-56
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    • 2008
  • Chimera grid methods have been widely used in Computational Fluid Dynamics due to its simplicity in constructing grid systems over complex bodies, and suitability for unsteady flow computations with bodies in relative motion. However, the interpolation procedure for ensuring the continuity of the solution over overlapped regions fails when the so-called orphan cells are present. We have adopted the MLS(Moving Least Squares) method to replace commonly used linear interpolations in order to alleviate the difficulty associated with the orphan cells. MLS is one of the interpolation methods used in mesh-less methods. A number of examples with MLS are presented to show the validity and the accuracy of the method.

Comparison of Interpolation Methods for Reconstructing Pin-wise Power Distribution in Hexagonal Geometry

  • Lee, Hyung-Seok;Yang, Won-Sik
    • Nuclear Engineering and Technology
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    • v.31 no.3
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    • pp.303-313
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    • 1999
  • Various interpolation methods have been compared for reconstruction of LMR pin power distributions in hexagonal geometry. Interpolation functions are derived for several combinations of nodal quantities and various sets of basis functions, and tested against fine mesh calculations. The test results indicate that the interpolation functions based on the sixth degree polynomial are quite accurate, yielding maximum interpolation errors in power densities less than 0.5%, and maximum reconstruction errors less than 2% for driver assemblies and less than 4% for blanket assemblies. The main contribution to the total reconstruction error is made tv the nodal solution errors and the comer point flux errors. For the polynomial interpolations, the basis monomial set needs to be selected such that the highest powers of x and y are as close as possible. It is also found that polynomials higher than the seventh degree are not adequate because of the oscillatory behavior.

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3D Matching by Stitching Technique and B-Spline Interpolations (Stitching 기술과 B-Spline에 의한 3차원 정합)

  • Yang, Han-Jin;Ahn, Min-Cheol;Joo, Young-Hoon;Lee, Kyu-Ho;Park, Byoung-Hae
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.1835_1836
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    • 2009
  • 본 논문에서는 비접촉식 미세 측정 광학기에 의해 측정된 이미지를 Stitching 기술과 B-Spline 보간법에 의해 보다 빠르고, 정밀한 복원 기법을 제안한다. 이를 위해 먼저 각각의 이미지로부터 매칭, 피매칭 템플릿(Template)을 검출한다. 그런 다음 두 이미지의 오버랩(Overlap)되는 부분을 기준하여 기준면으로부터 roll, pitch, yaw 오차를 계산하여 매칭시킨다. 마지막으로, B-Spline 보간법에 의해 매칭된 부분을 연속화한다. 제안된 방법은 실험을 통해 그 응용 가능성을 증명한다.

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H2 Design of Decoupled Control Systems Based on Directional Interpolations

  • Park, Kiheon;Kim, Jin-Geol
    • Journal of Electrical Engineering and Technology
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    • v.8 no.6
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    • pp.1551-1558
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    • 2013
  • $H_2$ design of decoupled control systems is treated in the generalized plant model. The existence condition of a decoupling controller is stated and a parameterized form of all achievable decoupled closed loop transfer matrices is presented by using the directional interpolation approaches under the assumption of simple transmission zeros. The class of all decoupling controllers that yield finite cost function is obtained as a parameterized form and an illustrative example to find the optimal controller is provided.

An Enhanced Chebyshev Collocation Method Based on the Integration of Chebyshev Interpolation

  • Kim, Philsu
    • Kyungpook Mathematical Journal
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    • v.57 no.2
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    • pp.287-299
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    • 2017
  • In this paper, we develop an enhanced Chebyshev collocation method based on an integration scheme of the generalized Chebyshev interpolations for solving stiff initial value problems. Unlike the former error embedded Chebyshev collocation method (CCM), the enhanced scheme calculates the solution and its truncation error based on the interpolation of the derivative of the true solution and its integration. In terms of concrete convergence and stability analysis, the constructed algorithm turns out to have the $7^{th}$ convergence order and the A-stability without any loss of advantages for CCM. Throughout a numerical result, we assess the proposed method is numerically more efficient compared to existing methods.

An universal NURBS interpolator for an architectured CNC controller (개방형 수치제어 장치를 위한 범용 NURBS 보간기)

  • 강성균
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.656-659
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    • 1996
  • An universal NURBS interpolation for an open architectured CNC controller is proposed in order to unify internal data structure and algorithm of different interpolations such as linear, circular and spline, and to intelligently interface CAD database of the various workpiece contour. Furthermore, NURBS interpolation may result in better surface roughness and high speed machining due to the continuous generation of cutter movement. The mathematical manipulation of NURBS is presented and the practical implementation on the CNC controller of a lathe is discussed for real machining. The comparison between a computer design and workpieces machined on a lathe shows the feasibility of the NURBS interpolation format as an universal interpolation scheme.

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Comparison with Water Quality of main Rivers in the world, based on OECD reports

  • Kambe, Junko;Aoyama, Tomoo;Nagashima, Umpei
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.935-940
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    • 2005
  • We are faced with water pollutions on a population explosion. Considering the importance, we research European rivers based on OECD reports. Observations in the reports have defects that make evaluation of environmental situations be difficult. By using interpolations in the compensation quantitative structure-activity relation ships (CQSAR), we complement the defects in the water quality of rivers through big cities. Thus, we get complete data set for dissolved oxygen, biochemical oxygen demand, and total phosphorus. Using the data set, we examine re-naturalization of the Rhein and the Donau in Germany. We investigate the effect of dams between Slovakia and Hungary, by using reconstructions of neural networks in CQSAR. The reconstructions have functions to extract a principal relation. On the investigation, we examine assertions of conservation groups. As the result, we confirm the re-naturalization is effective, and find a negative effect of the dam construction on changes of dissolved oxygens in the Hungary Donau. We investigate the Seine and the Thames, too.

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