In Cosserat solids such as shear deformable beams and shells, the displacement and rotation fields are independent. The finite element implementation of these structural components within the framework of flexible mul...
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In Cosserat solids such as shear deformable beams and shells, the displacement and rotation fields are independent. The finite element implementation of these structural components within the framework of flexible multibody dynamics requires the interpolation of rotation and motion fields. In general, the interpolation process does not preserve fundamental properties of the interpolated field. For instance, interpolation of an orthogonal rotation tensor does not yield an orthogonal tensor, and furthermore, does not preserve the tensorial nature of the rotation field. Consequently, many researchers have been reluctant to apply the classical interpolation tools used in finite element procedures to interpolate these fields. This paper presents a systematic study of interpolation algorithms for rotation and motion. All the algorithms presented here preserve the fundamental properties of the interpolated rotation and motion fields, and furthermore, preserve their tensorial nature. It is also shown that the interpolation of rotation and motion is as accurate as the interpolation of displacement, a widely accepted tool in the finite element method. The algorithms presented in this paper provide interpolation tools for rotation and motion that are accurate, easy to implement, and physically meaningful.
This paper presents an image interpolation model with local and nonlocal regularization. A nonlocal bounded variation (BV) regularizer is formulated by an exponential function including gradient. It acts as the Perona...
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This paper presents an image interpolation model with local and nonlocal regularization. A nonlocal bounded variation (BV) regularizer is formulated by an exponential function including gradient. It acts as the Perona-Malik equation. Thus our nonlocal BV regularizer possesses the properties of the anisotropic diffusion equation and nonlocal functional. The local total variation (TV) regularizer dissipates image energy along the orthogonal direction to the gradient to avoid blurring image edges. The derived model efficiently reconstructs the real image, leading to a natural interpolation which reduces blurring and staircase artifacts. We present experimental results that prove the potential and efficacy of the method.
In this paper the accuracy of the sine-wave frequency estimator returned by an iterative Interpolated Discrete Fourier Transform (IpDFT) algorithm based on a Maximum Sidelobe Decay (MSD) window is analyzed. The expres...
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ISBN:
(纸本)9781479961153
In this paper the accuracy of the sine-wave frequency estimator returned by an iterative Interpolated Discrete Fourier Transform (IpDFT) algorithm based on a Maximum Sidelobe Decay (MSD) window is analyzed. The expressions for the contribution to the frequency estimation error of either the spectral interference from the sine-wave image component and wideband noise are derived. It is shown that two algorithm iterations ensure the minimum noise sensitivity achievable with the adopted window. The accuracy of the derived expressions is verified by means of computer simulations and validated by experimental results.
A novel low-complexity and high-quality colour demosaicking algorithm is proposed for very large-scale integration (VLSI) implementation for real-time video applications. It consists of a boundary detector, a boundary...
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A novel low-complexity and high-quality colour demosaicking algorithm is proposed for very large-scale integration (VLSI) implementation for real-time video applications. It consists of a boundary detector, a boundary mirror model and five green and red-blue colour interpolation models. Two of the five interpolation models can be selected adaptively according to boundary and position information. In addition, a boundary mirror machine and identical direction technique were used to improve the qualities of the reconstructed images. To reduce the hardware cost, memory requirement and power consumption, a hardware-sharing technique and register bank design were used to realise the proposed algorithm. The VLSI architecture of this work contains only 2.9 K gate counts and its core area is 35 966 mu m(2) synthesised by a 0.18 mu m CMOS process. The synthesised results show that this design performs an operating frequency of 100 MHz processing rate by consuming only 1.83 mW. Compared with the previous low-complexity designs, this work not only reduces at least 48.2% of gate counts and 96.7% of power consumption but also improves the average CPSNR quality by more than 0.78 dB.
Based upon the fast computation of the coefficients of the interpolation polynomials at Chebyshev-type points by FFT, together with the efficient evaluation of the modified moments by forward recursions or by Oliver...
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Based upon the fast computation of the coefficients of the interpolation polynomials at Chebyshev-type points by FFT, together with the efficient evaluation of the modified moments by forward recursions or by Oliver's algorithms, this paper presents fast and stable interpolating integration algorithms, by using the coefficients and modified moments, for Clenshaw-Curtis, Fejer's first- and second-type rules for Jacobi weights or Jacobi weights multiplied by a logarithmic function. Numerical examples illustrate the stability, efficiency, and accuracy of these quadratures.
Current survey systems (LiDAR, multibeam echo sounders) allow the automated obtaining of a large amount of surface object measurements in a relatively short time. The large amount of information, survey specificity an...
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ISBN:
(纸本)9786094576409
Current survey systems (LiDAR, multibeam echo sounders) allow the automated obtaining of a large amount of surface object measurements in a relatively short time. The large amount of information, survey specificity and the character of the created data sets, as a rule, do not allow them to be used directly for the generation of the digital terrain model (DTM) in spatial information systems (SIS, GIS). The handling of measurement results of this type consists in optimization of set sizes and adaptation of their structure to both the user's requirements and technical processing capabilities. The specificity and universal character of the DTM information layer are an inducement to place particular emphasis on data recording organization and keeping their amount to a minimum. At the same time, it is intended to maintain maximum space description fidelity and its dynamic transformation. Efficient generation of information stored in digital map databases often requires data structure analysis and rationalization of the whole process with regard to processing speed. This paper shows an example of optimizing the efficiency of handling bulk measurement results for DTM creation using the GRID structure. Measurement sets and their processing sequence are also analysed. Methods for selecting the location of measurement points and efficient interpolation algorithms allowing an accurate GRID structure to be generated in a relatively short time are then presented.
The article presents a mathematical equation explaining Newton interpolation polynomial for the sums of powers of integers in response to the Lgrange interpolation polynomial formula for the powers of integers.
The article presents a mathematical equation explaining Newton interpolation polynomial for the sums of powers of integers in response to the Lgrange interpolation polynomial formula for the powers of integers.
General interpolation formulae for bivariate interpolation are established by introducing multiple parameters, which are extensions and improvements of those studied by Tan and Fang. The general interpolation formulae...
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General interpolation formulae for bivariate interpolation are established by introducing multiple parameters, which are extensions and improvements of those studied by Tan and Fang. The general interpolation formulae include general interpolation formulae of symmetric branched continued fraction, general interpolation formulae of univariate and bivariate interpolation, univariate block based blending rational interpolation, bivariate block based blending rational interpolation and their dual schemes, and some interpolation form studied by many scholars in recent years. We discuss the interpolation theorem, algorithms, dual interpolation, and special cases and give many kinds of interpolation scheme. Numerical examples are given to show the effectiveness of the method.
A general framework for image interpolation in a uniformly spaced image grid is presented. The proposed formulation is suitable for representing fractional (or sub-pixel) pixels as well as integer pixel interpolations...
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A general framework for image interpolation in a uniformly spaced image grid is presented. The proposed formulation is suitable for representing fractional (or sub-pixel) pixels as well as integer pixel interpolations. Also, by fitting an interpolation kernel to the grid formulation, finite impulse response filter coefficients can be readily determined for a given sampling interval and filter length. As an example, a four-tap lowpass filter is derived by fitting the Lagrange interpolation kernel to a row (or column) expansion by 2 on integer pixel locations.
We consider one-sided weight classes of Muckenhoupt type, but larger than the classical Muckenhoupt classes, and study the boundedness of one-sided oscillatory integral operators on weighted Lebesgue spaces using inte...
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We consider one-sided weight classes of Muckenhoupt type, but larger than the classical Muckenhoupt classes, and study the boundedness of one-sided oscillatory integral operators on weighted Lebesgue spaces using interpolation of operators with change of measures.
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