• Title/Summary/Keyword: Inverse Algorithm

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NEW ALGORITHM FOR THE DETERMINATION OF AN UNKNOWN PARAMETER IN PARABOLIC EQUATIONS

  • Yue, Sufang;Cui, Minggen
    • The Pure and Applied Mathematics
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    • v.15 no.1
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    • pp.19-34
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    • 2008
  • A new algorithm for the solution of an inverse problem of determining unknown source parameter in a parabolic equation in reproducing kernel space is considered. Numerical experiments are presented to demonstrate the accuracy and the efficiency of the proposed algorithm.

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Development of a motion system operating software for a driving simulator (차량 시뮬레이터의 운동시스템 구동소프트웨어 개발)

  • 박경균;박일경;조준희;이운성;김정하
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.496-499
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    • 1997
  • This paper describes the operating software of a motion system developed for a driving simulator, consisting of a six degree of freedom Stewart platform driven hydraulically. The drive logic, consisting of an washout algorithm, inverse kinematic analysis, and a control algorithm, has been developed and applied for creating high fidelity motion cues. The basic environment of the operating software is based on LabVIEW 4.0 and DLL modules compiled by Fortran.

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An Optimization of Ordering Algorithm for Sparse Vector Method (스파스벡터법을 위한 서열산법의 최적화)

  • Shin, Myong-Chul;Lee, Chun-Mo
    • Proceedings of the KIEE Conference
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    • 1989.07a
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    • pp.189-194
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    • 1989
  • The sparse vector method is more efficient than conventional sparse matrix method when solving sparse system. This paper considers the structural relation between factorized L and inverse of L and presents a new ordering algorithm for sparse vector method. The method is useful in enhancing the sparsity of the inverse of L while preserving the aparsity of matrix. The performance of algorithm is compared with conventional algorithms by means of several power system.

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Comparison and Performance Validation of On-line Aerial Triangulation Algorithms for Real-time Image Georeferencing (실시간 영상 지오레퍼런싱을 위한 온라인 항공삼각측량 알고리즘의 비교 및 성능 검증)

  • Choi, Kyoung-Ah;Lee, Im-Pyeong
    • Korean Journal of Remote Sensing
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    • v.28 no.1
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    • pp.55-67
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    • 2012
  • Real-time image georeferencing is required to generate spatial information rapidly from the image sequences acquired by multi-sensor systems. To complement the performance of position/attitude sensors and process in real-time, we should employ on-line aerial triangulation based on a sequential estimation algorithm. In this study, we thus attempt to derive an efficient on-line aerial triangulation algorithm for real-time georeferencing of image sequences. We implemented on-line aerial triangulation using the existing Given transformation update algorithm, and a new inverse normal matrix update algorithm based on observation classification, respectively. To compare the performance of two algorithms in terms of the accuracy and processing time, we applied these algorithms to simulated airborne multi-sensory data. The experimental results indicate that the inverse normal matrix update algorithm shows 40 % higher accuracy in the estimated ground point coordinates and eight times faster processing speed comparing to the Given transformation update algorithm. Therefore, the inverse normal matrix update algorithm is more appropriate for the real-time image georeferencing.

Analytical Approximation Algorithm for the Inverse of the Power of the Incomplete Gamma Function Based on Extreme Value Theory

  • Wu, Shanshan;Hu, Guobing;Yang, Li;Gu, Bin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.12
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    • pp.4567-4583
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    • 2021
  • This study proposes an analytical approximation algorithm based on extreme value theory (EVT) for the inverse of the power of the incomplete Gamma function. First, the Gumbel function is used to approximate the power of the incomplete Gamma function, and the corresponding inverse problem is transformed into the inversion of an exponential function. Then, using the tail equivalence theorem, the normalized coefficient of the general Weibull distribution function is employed to replace the normalized coefficient of the random variable following a Gamma distribution, and the approximate closed form solution is obtained. The effects of equation parameters on the algorithm performance are evaluated through simulation analysis under various conditions, and the performance of this algorithm is compared to those of the Newton iterative algorithm and other existing approximate analytical algorithms. The proposed algorithm exhibits good approximation performance under appropriate parameter settings. Finally, the performance of this method is evaluated by calculating the thresholds of space-time block coding and space-frequency block coding pattern recognition in multiple-input and multiple-output orthogonal frequency division multiplexing. The analytical approximation method can be applied to other related situations involving the maximum statistics of independent and identically distributed random variables following Gamma distributions.

Finite Element Inverse Analysis of the Deep Drawing Process Considering Bending History (굽힘이력을 고려한 딥드로잉공정의 유한요소역해석)

  • Huh, J.;Yoon, J.H.;Bao, Y.D.;Huh, H.
    • Transactions of Materials Processing
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    • v.16 no.8
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    • pp.590-595
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    • 2007
  • This paper introduces a new approach to take account of bending history in finite element inverse analysis during sheet metal forming process. A modified membrane element was adopted for finite element inverse analysis so that bending-unbending energy was additionally imposed in the total plastic energy, predicting bending-unbending regions using the geometry of the final shape and tools. An algorithm was applied to a cylindrical cup deep drawing process. The blank shape and the distribution of the thickness strain were compared with those obtained from the incremental finite element analysis in order to evaluate the effect of the bending history. The algorithm reduced the difference between the results of the inverse analysis from those of the incremental analysis due to bending history. The analysis was also carried out with the variation of the thickness of the initial blank to investigate the effect of bending deformation. The results showed that the difference was remarkably reduced as the thickness of the initial blank increased. This indicates that the finite element inverse analysis cooperated with the suggested scheme is useful to obtain more accurate results, especially when bending effects are significant.

Finite Element Inverse Analysis of the Cylindrical Cup Deep Drawing Process Considering Bending History (굽힘이력을 고려한 원형컵 딥드로잉공정의 유한요소역해석)

  • Huh, J.;Yoon, J.H.;Bao, Y.D.;Huh, H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2007.05a
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    • pp.340-343
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    • 2007
  • This paper introduces a new approach to consider the bending history in finite element inverse analysis of the cylindrical cup drawing. A modified membrane element is adopted to add the bending-unbending energy to the total plastic energy on the bending-unbending region predicted from the geometry of the final shape and tools. The algorithm suggested was applied to a cylindrical cup deep drawing process. The blank shape and the distribution of the thickness strain are compared with those obtained from incremental finite element analysis. The comparison demonstrates the algorithm proposed reduces the difference between the results from inverse analysis and those from incremental analysis when the bending history is considered.

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An Efficient Inverse Kinematics Solution Method for the 6 Axes Robot with Offest Wrist (손목오프셋을 갖는 6축 로봇을 위한 효과적인 역기구학 해 방법)

  • 범진환;임생기;손명현
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.6
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    • pp.1421-1429
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    • 1994
  • An algorithm is developed for solving the inverse kinematic problem of a 6-degree-of-freedom robot with a wrist offset for which the closed form inverse solutions are not obtainable, but knowledge of one joint variable allows closed form solutions of the remaining joint variables. The algorithm does not require Forward Kinematics nor Jacobian but uses the implicit kinematic relationships between joint variables and the given hand position. An iterative back substitution method is used to solve the inversion and the optimal conditions of the convergence are incoporated. An example is given to illustrate the concepts, the solution procedure and its convergency.

A PRECONDITIONER FOR THE NORMAL EQUATIONS

  • Salkuyeh, Davod Khojasteh
    • Journal of applied mathematics & informatics
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    • v.28 no.3_4
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    • pp.687-696
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    • 2010
  • In this paper, an algorithm for computing the sparse approximate inverse factor of matrix $A^{T}\;A$, where A is an $m\;{\times}\;n$ matrix with $m\;{\geq}\;n$ and rank(A) = n, is proposed. The computation of the inverse factor are done without computing the matrix $A^{T}\;A$. The computed sparse approximate inverse factor is applied as a preconditioner for solving normal equations in conjunction with the CGNR algorithm. Some numerical experiments on test matrices are presented to show the efficiency of the method. A comparison with some available methods is also included.

Performance Enhancement of Whistle Sound Source Tracking Algorithm using Time-Scale Filter Based on Wavelet Transform

  • Moon, Serng-Bae
    • Journal of Navigation and Port Research
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    • v.28 no.2
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    • pp.135-140
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    • 2004
  • A purpose of developing a sound source tracking system in this paper is to reduce the noise efficiently from the received signal by microphone array and measure the signal's time delay between the microphones. I have applied the wavelet analysis algorithm to the system and calculated the sound source's relative position For the performance evaluation, I have compared with the results of utilizing the digital filtering methods based on the FIR LPF using Kaiser window function and the inverse Chebyshev IIR LPF. As a result, I have confirmed the fact that 'time-scale' filter using inverse discrete wavelet transform was suitable for this system.