Wavelets associated with Hankel transform and their Weyl transforms
PENG; Lizhong; MA; Ruiqin
2004-01-01
The Hankel transform is an important transform. In this paper, westudy the wavelets associated with the Hankel transform, thendefine the Weyl transform of the wavelets. We give criteria of itsboundedness and compactness on the Lp-spaces.
Stable Numerical Evaluation of Finite Hankel Transforms and Their Application
Manoj P. Tripathi
2014-01-01
Full Text Available A new stable algorithm, based on hat functions for numerical evaluation of Hankel transform of order ν>-1, is proposed in this paper. The hat basis functions are used as a basis to expand a part of the integrand, rf(r, appearing in the Hankel transform integral. This leads to a very simple, efficient, and stable algorithm for the numerical evaluation of Hankel transform. The novelty of our paper is that we give error and stability analysis of the algorithm and corroborate our theoretical findings by various numerical experiments. Finally, an application of the proposed algorithm is given for solving the heat equation in an infinite cylinder with a radiation condition.
Hankel transforms in generalized Fock spaces
John Schmeelk
1994-01-01
Full Text Available A classical Fock space consists of functions of the form,ϕ↔(ϕ0,ϕ1,…,ϕq,where ϕ0∈ℂ and ϕq∈Lp(ℝq, q≥1. We will replace the ϕq, q≥1 with test functions having Hankel transforms. This space is a natural generalization of a classical Fock space as seen by expanding functionals having abstract Taylor Series. The particular coefficients of such series are multilinear functionals having distributions as their domain. Convergence requirements set forth are somewhat in the spirit of ultra differentiable functions and ultra distribution theory. The Hankel transform oftentimes implemented in Cauchy problems will be introduced into this setting. A theorem will be proven relating the convergence of the transform to the inductive limit parameter, s, which sweeps out a scale of generalized Fock spaces.
On Quantum Mechanical Hankel Transform and Its Applications
无
2007-01-01
Based on our preceding works of how to relate the mathematical Hankel transform to quantum mechanical representation transform and how to express the Bessel equation by an operator identity in some appropriate representations we propose the concept of quantum mechanical Hankel transform with regard to quantum state vectors. Then we discuss its new applications.
Combinatorial polynomials as moments, Hankel transforms and exponential Riordan arrays
Barry, Paul
2011-01-01
In the case of two combinatorial polynomials, we show that they can exhibited as moments of paramaterized families of orthogonal polynomials, and hence derive their Hankel transforms. Exponential Riordan arrays are the main vehicles used for this.
Hankel complementary integral transformations of arbitrary order
M. Linares Linares
1992-01-01
Full Text Available Four selfreciprocal integral transformations of Hankel type are defined through(ℋi,μf(y=Fi(y=∫0∞αi(xℊi,μ(xyf(xdx, ℋi,μ−1=ℋi,μ,where i=1,2,3,4; μ≥0; α1(x=x1+2μ, ℊ1,μ(x=x−μJμ(x, Jμ(x being the Bessel function of the first kind of order μ; α2(x=x1−2μ, ℊ2,μ(x=(−1μx2μℊ1,μ(x; α3(x=x−1−2μ, ℊ3,μ(x=x1+2μℊ1,μ(x, and α4(x=x−1+2μ, ℊ4,μ(x=(−1μxℊ1,μ(x. The simultaneous use of transformations ℋ1,μ, and ℋ2,μ, (which are denoted by ℋμ allows us to solve many problems of Mathematical Physics involving the differential operator Δμ=D2+(1+2μx−1D, whereas the pair of transformations ℋ3,μ and ℋ4,μ, (which we express by ℋμ* permits us to tackle those problems containing its adjoint operator Δμ*=D2−(1+2μx−1D+(1+2μx−2, no matter what the real value of μ be. These transformations are also investigated in a space of generalized functions according to the mixed Parseval equation∫0∞f(xg(xdx=∫0∞(ℋμf(y(ℋμ*g(ydy,which is now valid for all real μ.
FAN Hong-Yi; WANG Yong
2006-01-01
In Phys. Lett. A 313 (2003) 343 we have found that the self-reciprocal Hankel transformation (HT) is embodied in quantum mechanics by a transform between two entangled state representations of continuum variables. In this work we study Hankel transforms and properties of Bessel function via entangled state representations' transformation in quantum mechanics.
An -Dimensional Pseudo-Differential Operator Involving the Hankel Transformation
R S Pathak; Akhilesh Prasad; Manish Kumar
2012-02-01
An -dimensional pseudo-differential operator (p.d.o.) involving the -dimensional Hankel transformation is defined. The symbol class $H^m$ is introduced. It is shown that p.d.o.'s associated with symbols belonging to this class are continuous linear mappings of the -dimensional Zemanian space $H_(I^n)$ into itself. An integral representation for the p.d.o. is obtained. Using the Hankel convolution, it is shown that the p.d.o. satisfies a certain 1-norm inequality.
The Hankel Transform of q-Noncentral Bell Numbers
Cristina B. Corcino
2015-01-01
Full Text Available We define two forms of q-analogue of noncentral Stirling numbers of the second kind and obtain some properties parallel to those of noncentral Stirling numbers. Certain combinatorial interpretation is given for the second form of the q-analogue in the context of 0-1 tableaux which, consequently, yields certain additive identity and some convolution-type formulas. Finally, a q-analogue of noncentral Bell numbers is defined and its Hankel transform is established.
Hankel transform of a sequence obtained by series reversion II - aerating transforms
Bojičić, Radica; Barry, Paul
2011-01-01
This paper provides the connection between the Hankel transform and aerating transforms of a given integer sequence. Results obtained are used to establish a completely different Hankel transform evaluation of the series reversion of a certain rational function $Q(x)$ and shifted sequences, recently published in our paper \\cite{part1}. For that purpose, we needed to evaluate the Hankel transforms of the sequences $\\seqn{\\alpha^2 C_n-\\beta C_{n+1}}$ and $\\seqn{\\alpha^2 C_{n+1}-\\beta C_{n+2}}$, where $C=\\seqn{C_n}$ is the well-known sequence of Catalan numbers. This generalizes the results of Cvetkovi\\' c, Rajkovi\\'c and Ivkovi\\'c \\cite{CRI}. Also, we need the evaluation of Hankel-like determinants whose entries are Catalan numbers $C_n$ and which is based on the recent results of Krattenthaler \\cite{krattCat}. The results obtained are general and can be applied to many other Hankel transform evaluations.
FAN Hong-Yi
2004-01-01
We find quantum mechanical Fourier-Hankel representation transform for an electron moving in a uniform magnetic field. The physical meaning of Fourier decomposition states of electron's coordinate eigenstate and the momentum eigenstate are revealed.
The Bessel differential equation and the Hankel transform
Everitt, W. N.; Kalf, H.
2007-11-01
This paper studies the classical second-order Bessel differential equation in Liouville form:Here, the parameter [nu] represents the order of the associated Bessel functions and [lambda] is the complex spectral parameter involved in considering properties of the equation in the Hilbert function space L2(0,[infinity]). Properties of the equation are considered when the order [nu][set membership, variant][0,1); in this case the singular end-point 0 is in the limit-circle non-oscillatory classification in the space L2(0,[infinity]); the equation is in the strong limit-point and Dirichlet condition at the end-point +[infinity]. Applying the generalised initial value theorem at the singular end-point 0 allows of the definition of a single Titchmarsh-Weyl m-coefficient for the whole interval (0,[infinity]). In turn this information yields a proof of the Hankel transform as an eigenfunction expansion for the case when [nu][set membership, variant][0,1), a result which is not available in the existing literature. The application of the principal solution, from the end-point 0 of the Bessel equation, as a boundary condition function yields the Friedrichs self-adjoint extension in L2(0,[infinity]); the domain of this extension has many special known properties, of which new proofs are presented.
Pravin K Gupta; Sri Niwas; Neeta Chaudhary
2006-06-01
The computation of electromagnetic (EM)ﬁelds,for 1-D layered earth model,requires evaluation of Hankel Transform (HT)of the EM kernel function.The digital ﬁltering is the most widely used technique to evaluate HT integrals.However,it has some obvious shortcomings.We present an alternative scheme,based on an orthonormal exponential approximation of the kernel function, for evaluating HT integrals.This approximation of the kernel function was chosen because the analytical solution of HT of an exponential function is readily available in literature.This expansion reduces the integral to a simple algebraic sum.The implementation of such a scheme requires that the weights and the exponents of the exponential function be estimated.The exponents were estimated through a guided search algorithm while the weights were obtained using Marquardt matrix inversion method.The algorithm was tested on analytical HT pairs available in literature. The results are compared with those obtained using the digital ﬁltering technique with Anderson ﬁlters.The ﬁeld curves for four types (A-,K-,H-and Q-type)of 3-layer earth models are generated using the present scheme and compared with the corresponding curves obtained using the Anderson scheme.It is concluded that the present scheme is more accurate than the Anderson scheme.
Polyconvolution and the Toeplitz plus Hankel integral equation
Nguyen Xuan Thao
2014-04-01
Full Text Available In this article we introduce a polyconvolution which related to the Hartley and Fourier cosine transforms. We prove some properties of this polyconvolution, and then solve a class of Toeplitz plus Hankel integral equations and systems of two Toeplitz plus Hankel integral equations.
Hankel Operators and Gramians for Nonlinear Systems
Gray, W. Steven; Scherpen, Jacquelien M.A.
1998-01-01
In the theory for continuous-time linear systems, the system Hankel operator plays an important role in a number of realization problems ranging from providing an abstract notion of state to yielding tests for state space minimality and algorithms for model reduction. But in the case of continuous-t
A Class of Weighted Low Rank Approximation of the Positive Semidefinite Hankel Matrix
Jianchao Bai
2015-01-01
Full Text Available We consider the weighted low rank approximation of the positive semidefinite Hankel matrix problem arising in signal processing. By using the Vandermonde representation, we firstly transform the problem into an unconstrained optimization problem and then use the nonlinear conjugate gradient algorithm with the Armijo line search to solve the equivalent unconstrained optimization problem. Numerical examples illustrate that the new method is feasible and effective.
Legaie, D.; Pron, H.; Bissieux, C.
2008-11-01
Integral transforms (Laplace, Fourier, Hankel) are widely used to solve the heat diffusion equation. Moreover, it often appears relevant to realize the estimation of thermophysical properties in the transformed space. Here, an analytical model has been developed, leading to a well-posed inverse problem of parameter identification. Two black coatings, a thin black paint layer and an amorphous carbon film, were studied by photothermal infrared thermography. A Hankel transform has been applied on both thermal model and data and the estimation of thermal diffusivity has been achieved in the Hankel space. The inverse problem is formulated as a non-linear least square problem and a Gauss-Newton algorithm is used for the parameter identification.
Shen, Zhiyuan; Feng, Naizhang; Lee, Chin-Hui
2013-04-01
Clutter regarded as ultrasound Doppler echoes of soft tissue interferes with the primary objective of color flow imaging (CFI): measurement and display of blood flow. Multi-ensemble samples based clutter filters degrade resolution or frame rate of CFI. The prevalent single-ensemble clutter rejection filter is based on a single rejection criterion and fails to achieve a high accuracy for estimating both the low- and high-velocity blood flow components. The Bilinear Hankel-SVD achieved more exact signal decomposition than the conventional Hankel-SVD. Furthermore, the correlation between two arbitrary eigen-components obtained by the B-Hankel-SVD was demonstrated. In the hybrid approach, the input ultrasound Doppler signal first passes through a low-order regression filter, and then the output is properly decomposed into a collection of eigen-components under the framework of B-Hankel-SVD. The blood flow components are finally extracted based on a frequency threshold. In a series of simulations, the proposed B-Hankel-SVD filter reduced the estimation bias of the blood flow over the conventional Hankel-SVD filter. The hybrid algorithm was shown to be more effective than regression or Hankel-SVD filters alone in rejecting the undesirable clutter components with single-ensemble (S-E) samples. It achieved a significant improvement in blood flow frequency estimation and estimation variance over the other competing filters.
Little Hankel operators on the Bergman space
Namita Das
2016-01-01
Full Text Available In this paper we obtain a characterization of little Hankel operators defined on the Bergman space of the unit disk and then extend the result to vector valued Bergman spaces. We then derive from it certain asymptotic properties of little Hankel operators.
Series expansions for the incomplete Lipschitz-Hankel integralYe 0(a, z)
Mechaik, Mehdi M.; Dvorak, Steven L.
1996-03-01
Three series expansions are derived for the incomplete Lipschitz-Hankel integral YeO(a, z) for complex-valued a and z. Two novel expansions are obtained by using contour integration techniques to evaluate the inverse Laplace transform representation for YeO(a, z). A third expansion is obtained by replacing the Neumann function by its Neumann series representation and integrating the resulting terms. An algorithm is outlined which chooses the most efficient expansion for given values of a and z. Comparisons of numerical results for these series expansions with those obtained by using numerical integration routines show that the expansions are very efficient and yield accurate results even for values of a and z for which numerical integration fails to converge. The integral representations for YeO(a, z) obtained in this paper are combined with previously obtained integral representations for Jeo(a, z) to derive integral representations for HeO(1) (a, z) and HeO(2) (α, z). Recurrence relations can be used to efficiently compute higher-order incomplete Lipschitz-Hankel integrals and to find integral representations and series expansions for these special functions and many other related functions.
New Algorithm For Calculating Wavelet Transforms
Piotr Lipinski
2009-04-01
Full Text Available In this article we introduce a new algorithm for computing Discrete Wavelet Transforms (DWT. The algorithm aims at reducing the number of multiplications, required to compute a DWT. The algorithm is general and can be used to compute a variety of wavelet transform (Daubechies and CDF. Here we focus on CDF 9/7 filters, which are used in JPEG2000 compression standard. We show that the algorithm outperforms convolution-based and lifting-based algorithms in terms of number of multiplications.
Comparison of fast discrete wavelet transform algorithms
MENG Shu-ping; TIAN Feng-chun; XU Xin
2005-01-01
This paper presents an analysis on and experimental comparison of several typical fast algorithms for discrete wavelet transform (DWT) and their implementation in image compression, particularly the Mallat algorithm, FFT-based algorithm, Short-length based algorithm and Lifting algorithm. The principles, structures and computational complexity of these algorithms are explored in details respectively. The results of the experiments for comparison are consistent to those simulated by MATLAB. It is found that there are limitations in the implementation of DWT. Some algorithms are workable only for special wavelet transform, lacking in generality. Above all, the speed of wavelet transform, as the governing element to the speed of image processing, is in fact the retarding factor for real-time image processing.
Vectorial rotating vortex Hankel laser beams
Kotlyar, Victor V.; Kovalev, Alexey A.; Soifer, Victor A.
2016-09-01
We propose a generalization of spherical waves in the form of linearly polarized beams with embedded optical vortices. The source of these beams is an infinitely narrow light ring with an infinitely small radius. These vectorial beams are obtained based on scalar Hankel beams discovered by the authors recently. We have derived explicit relations for complex amplitudes of all six components of vectorial vortex Hankel beams. A closed analytical expression for the axial projection of the orbital angular momentum density in far field has been obtained. We also showed that the intensity distribution of the electric vector rotates by 90 degrees upon the beam propagation in near field.
Commuting Toeplitz and Hankel Operators on Harmonic Dirichlet Spaces
Qian Ding
2017-01-01
Full Text Available On the harmonic Dirichlet space of the unit disk, the commutativity of Toeplitz and Hankel operators is studied. We obtain characterizations of commuting Toeplitz and Hankel operators and essentially commuting (semicommuting Toeplitz and Hankel operators with general symbols.
Fast Fourier Transform algorithm design and tradeoffs
Kamin, Ray A., III; Adams, George B., III
1988-01-01
The Fast Fourier Transform (FFT) is a mainstay of certain numerical techniques for solving fluid dynamics problems. The Connection Machine CM-2 is the target for an investigation into the design of multidimensional Single Instruction Stream/Multiple Data (SIMD) parallel FFT algorithms for high performance. Critical algorithm design issues are discussed, necessary machine performance measurements are identified and made, and the performance of the developed FFT programs are measured. Fast Fourier Transform programs are compared to the currently best Cray-2 FFT program.
A fast DFT algorithm using complex integer transforms
Reed, I. S.; Truong, T. K.
1978-01-01
Winograd's algorithm for computing the discrete Fourier transform is extended considerably for certain large transform lengths. This is accomplished by performing the cyclic convolution, required by Winograd's method, by a fast transform over certain complex integer fields. This algorithm requires fewer multiplications than either the standard fast Fourier transform or Winograd's more conventional algorithms.
Parallel algorithms for the spectral transform method
Foster, I.T. [Argonne National Lab., IL (United States); Worley, P.H. [Oak Ridge National Lab., TN (United States)
1994-04-01
The spectral transform method is a standard numerical technique for solving partial differential equations on a sphere and is widely used in atmospheric circulation models. Recent research has identified several promising algorithms for implementing this method on massively parallel computers; however, no detailed comparison of the different algorithms has previously been attempted. In this paper, we describe these different parallel algorithms and report on computational experiments that we have conducted to evaluate their efficiency on parallel computers. The experiments used a testbed code that solves the nonlinear shallow water equations or a sphere; considerable care was taken to ensure that the experiments provide a fair comparison of the different algorithms and that the results are relevant to global models. We focus on hypercube- and mesh-connected multicomputers with cut-through routing, such as the Intel iPSC/860, DELTA, and Paragon, and the nCUBE/2, but also indicate how the results extend to other parallel computer architectures. The results of this study are relevant not only to the spectral transform method but also to multidimensional FFTs and other parallel transforms.
Balanced random Toeplitz and Hankel Matrices
Basak, Anirban
2010-01-01
Except the Toeplitz and Hankel matrices, the common patterned matrices for which the limiting spectral distribution (LSD) are known to exist, share a common property--the number of times each random variable appears in the matrix is (more or less) same across the variables. Thus it seems natural to ask what happens to the spectrum of the Toeplitz and Hankel matrices when each entry is scaled by the square root of the number of times that entry appears in the matrix instead of the uniform scaling by $n^{-1/2}$. We show that the LSD of these balanced matrices exist and derive integral formulae for the moments of the limit distribution. Curiously, it is not clear if these moments define a unique distribution.
Libpsht - algorithms for efficient spherical harmonic transforms
Reinecke, Martin
2010-01-01
Libpsht (or "library for Performant Spherical Harmonic Transforms") is a collection of algorithms for efficient conversion between spatial-domain and spectral-domain representations of data defined on the sphere. The package supports transforms of scalars as well as spin-1 and spin-2 quantities, and can be used for a wide range of pixelisations (including HEALPix, GLESP and ECP). It will take advantage of hardware features like multiple processor cores and floating-point vector operations, if available. Even without this additional acceleration, the employed algorithms are among the most efficient (in terms of CPU time as well as memory consumption) currently being used in the astronomical community. The library is written in strictly standard-conforming C90, ensuring portability to many different hard- and software platforms, and allowing straightforward integration with codes written in various programming languages like C, C++, Fortran, Python etc. Libpsht is distributed under the terms of the GNU General ...
A simple denoising algorithm using wavelet transform
Roy, M F; Kulkarni, B D; Sanderson, J; Rhodes, M; Stappen, M; Roy, Manojit; Sanderson, John; Rhodes, Martin; Stappen, Michel vander
1999-01-01
We have presented a new and alternative algorithm for noise reduction using the methods of discrete wavelet transform and numerical differentiation of the data. In our method the threshold for reducing noise comes out automatically. The algorithm has been applied to three model flow systems - Lorenz, Autocatalator, and Rossler systems - all evolving chaotically. The method is seen to work quite well for a wide range of noise strengths, even as large as 10% of the signal level. We have also applied the method successfully to noisy time series data obtained from the measurement of pressure fluctuations in a fluidized bed, and also to that obtained by conductivity measurement in a liquid surfactant experiment. In all the illustrations we have been able to observe that there is a clean separation in the frequencies covered by the differentiated signal and white noise.
An intersection algorithm based on transformation
CHEN Xiao-xia; YONG Jun-hai; CHEN Yu-jian
2006-01-01
How to obtain intersection of curves and surfaces is a fundamental problem in many areas such as computer graphics,CAD/CAM,computer animation,and robotics.Especially,how to deal with singular cases,such as tangency or superposition,is a key problem in obtaining intersection results.A method for solving the intersection problem based on the coordinate transformation is presented.With the Lagrange multiplier method,the minimum distance between the center of a circle and a quadric surface is given as well.Experience shows that the coordinate transformation could significantly simplify the method for calculating intersection to the tangency condition.It can improve the stability of the intersection of given curves and surfaces in singularity cases.The new algorithm is applied in a three dimensional CAD software (GEMS),produced by Tsinghua University.
Image fusion algorithm using nonsubsampled contourlet transform
Xiao, Yang; Cao, Zhiguo; Wang, Kai; Xu, Zhengxiang
2007-11-01
In this paper, a pixel-level image fusion algorithm based on Nonsubsampled Contourlet Transform (NSCT) has been proposed. Compared with Contourlet Transform, NSCT is redundant, shift-invariant and more suitable for image fusion. Each image from different sensors could be decomposed into a low frequency image and a series of high frequency images of different directions by multi-scale NSCT. For low and high frequency images, they are fused based on local-contrast enhancement and definition respectively. Finally, fused image is reconstructed from low and high frequency fused images. Experiment demonstrates that NSCT could preserve edge significantly and the fusion rule based on region segmentation performances well in local-contrast enhancement.
Annihilating Filter-Based Low-Rank Hankel Matrix Approach for Image Inpainting.
Jin, Kyong Hwan; Ye, Jong Chul
2015-11-01
In this paper, we propose a patch-based image inpainting method using a low-rank Hankel structured matrix completion approach. The proposed method exploits the annihilation property between a shift-invariant filter and image data observed in many existing inpainting algorithms. In particular, by exploiting the commutative property of the convolution, the annihilation property results in a low-rank block Hankel structure data matrix, and the image inpainting problem becomes a low-rank structured matrix completion problem. The block Hankel structured matrices are obtained patch-by-patch to adapt to the local changes in the image statistics. To solve the structured low-rank matrix completion problem, we employ an alternating direction method of multipliers with factorization matrix initialization using the low-rank matrix fitting algorithm. As a side product of the matrix factorization, locally adaptive dictionaries can be also easily constructed. Despite the simplicity of the algorithm, the experimental results using irregularly subsampled images as well as various images with globally missing patterns showed that the proposed method outperforms existing state-of-the-art image inpainting methods.
A Disjoint Set Algorithm for the Watershed Transform
Meijster, Arnold; Roerdink, Jos B.T.M.; Theodoridis, S; Pitas, I; Stouraitis, A; Kalouptsidis, N
1998-01-01
In this paper the implementation of a watershed transform based on Tarjan’s Union-Find algorithm is described. The algorithm computes the watershed as defined previously. The algorithm consists of two stages. In the first stage the image to be segmented is transformed into a lower complete image,
A Disjoint Set Algorithm for the Watershed Transform
Meijster, Arnold; Roerdink, Jos B.T.M.; Theodoridis, S; Pitas, I; Stouraitis, A; Kalouptsidis, N
1998-01-01
In this paper the implementation of a watershed transform based on Tarjan’s Union-Find algorithm is described. The algorithm computes the watershed as defined previously. The algorithm consists of two stages. In the first stage the image to be segmented is transformed into a lower complete image, us
Fast Algorithm for Nonsubsampled Contourlet Transform
YAN Chun-Man; GUO Bao-Long; YI Meng
2014-01-01
The multiscale geometric analysis (MGA) has been recognized as an effective strategy for image processing. As one of the discrete tools of MGA, the nonsubsampled contourlet transform (NSCT) has been widely used for image denoising, image fusion, image enhancement, feature extraction and so on. However, the processing performance is limited due to its high redundancy, and leading to an intensive computational efficiency. Therefore, its fast algorithm is desired in practice. In this paper, we adopt an optimized directional filter bank (DFB) and embed it into the NSCT to significantly accelerate the computational speed while keeping slight loss of the reconstructed performance. Experimental results show that the reconstructed image quality can satisfy the human visual system. Moreover, the improved NSCT has a speed about several times than that of the traditional one. Experimental results on image denoising also validate the feasibility and efficiency of the proposed method.
Interpolation by Hankel Translates of a Basis Function: Inversion Formulas and Polynomial Bounds
Cristian Arteaga
2014-01-01
Full Text Available For μ≥−1/2, the authors have developed elsewhere a scheme for interpolation by Hankel translates of a basis function Φ in certain spaces of continuous functions Yn (n∈ℕ depending on a weight w. The functions Φ and w are connected through the distributional identity t4n(hμ′Φ(t=1/w(t, where hμ′ denotes the generalized Hankel transform of order μ. In this paper, we use the projection operators associated with an appropriate direct sum decomposition of the Zemanian space ℋμ in order to derive explicit representations of the derivatives SμmΦ and their Hankel transforms, the former ones being valid when m∈ℤ+ is restricted to a suitable interval for which SμmΦ is continuous. Here, Sμm denotes the mth iterate of the Bessel differential operator Sμ if m∈ℕ, while Sμ0 is the identity operator. These formulas, which can be regarded as inverses of generalizations of the equation (hμ′Φ(t=1/t4nw(t, will allow us to get some polynomial bounds for such derivatives. Corresponding results are obtained for the members of the interpolation space Yn.
Interpolation by Hankel translates of a basis function: inversion formulas and polynomial bounds.
Arteaga, Cristian; Marrero, Isabel
2014-01-01
For μ≥-1/2, the authors have developed elsewhere a scheme for interpolation by Hankel translates of a basis function Φ in certain spaces of continuous functions Yn(n∈ℕ) depending on a weight w. The functions Φ and w are connected through the distributional identity t4n(hμ'Φ)(t)=1/w(t), where hμ' denotes the generalized Hankel transform of order μ. In this paper, we use the projection operators associated with an appropriate direct sum decomposition of the Zemanian space ℋμ in order to derive explicit representations of the derivatives SμmΦ and their Hankel transforms, the former ones being valid when m∈ℤ+ is restricted to a suitable interval for which SμmΦ is continuous. Here, Sμm denotes the mth iterate of the Bessel differential operator Sμ if m∈ℕ, while Sμ0 is the identity operator. These formulas, which can be regarded as inverses of generalizations of the equation (hμ'Φ)(t)=1/t4nw(t), will allow us to get some polynomial bounds for such derivatives. Corresponding results are obtained for the members of the interpolation space Y n .
Fast algorithm for computing complex number-theoretic transforms
Reed, I. S.; Liu, K. Y.; Truong, T. K.
1977-01-01
A high-radix FFT algorithm for computing transforms over FFT, where q is a Mersenne prime, is developed to implement fast circular convolutions. This new algorithm requires substantially fewer multiplications than the conventional FFT.
RESEARCH OF PROBLEMS ON REALIZING DIRECT ALGORITHM OF WAVELET TRANSFORM
无
2003-01-01
Direct algorithm of wavelet transform (WT) is the numerical algorithm obtained from the integral formula of WT by directly digitization.Some problems on realizing the algorithm are studied.Some conclusions on the direct algorithm of discrete wavelet transform (DWT), such as discrete convolution operation formula of wavelet coefficients and wavelet components, sampling principle and technology to wavelets, deciding method for scale range of wavelets, measures to solve edge effect problem, etc, are obtained.The realization of direct algorithm of continuous wavelet transform (CWT) is also studied.The computing cost of direct algorithm and Mallat algorithm of DWT are still studied, and the computing formulae are obtained.These works are beneficial to deeply understand WT and Mallat algorithm.Examples in the end show that direct algorithm can also be applied widely.
On a Generalized Hankel Type Convolution of Generalized Functions
S P Malgonde; G S Gaikawad
2001-11-01
The classical generalized Hankel type convolution are defined and extended to a class of generalized functions. Algebraic properties of the convolution are explained and the existence and significance of an identity element are discussed.
MUTUAL IMAGE TRANSFORMATION ALGORITHMS FOR VISUAL INFORMATION PROCESSING AND RETRIEVAL
G. A. Kukharev
2017-01-01
Full Text Available Subject of Research. The paper deals with methods and algorithms for mutual transformation of related pairs of images in order to enhance the capabilities of cross-modal multimedia retrieval (CMMR technologies. We have thoroughly studied the problem of mutual transformation of face images of various kinds (e.g. photos and drawn pictures. This problem is widely represented in practice. Research is this area is based on existing datasets. The algorithms we have proposed in this paper can be applied to arbitrary pairs of related images due to the unified mathematical specification. Method. We have presented three image transformation algorithms. The first one is based on principal component analysis and Karhunen-Loève transform (1DPCA/1DKLT. Unlike the existing solution, it does not use the training set during the transformation process. The second algorithm assumes generation of an image population. The third algorithm performs the transformation based on two-dimensional principal component analysis and Karhunen-Loève transform (2DPCA/2DKLT. Main Results. The experiments on image transformation and population generation have revealed the main features of each algorithm. The first algorithm allows construction of an accurate and stable model of transition between two given sets of images. The second algorithm can be used to add new images to existing bases and the third algorithm is capable of performing the transformation outside the training dataset. Practical Relevance. Taking into account the qualities of the proposed algorithms, we have provided recommendations concerning their application. Possible scenarios include construction of a transition model for related pairs of images, mutual transformation of the images inside and outside the dataset as well as population generation in order to increase representativeness of existing datasets. Thus, the proposed algorithms can be used to improve reliability of face recognition performed on images
A fast rank-reduction algorithm for three-dimensional seismic data interpolation
Jia, Yongna; Yu, Siwei; Liu, Lina; Ma, Jianwei
2016-09-01
Rank-reduction methods have been successfully used for seismic data interpolation and noise attenuation. However, highly intense computation is required for singular value decomposition (SVD) in most rank-reduction methods. In this paper, we propose a simple yet efficient interpolation algorithm, which is based on the Hankel matrix, for randomly missing traces. Following the multichannel singular spectrum analysis (MSSA) technique, we first transform the seismic data into a low-rank block Hankel matrix for each frequency slice. Then, a fast orthogonal rank-one matrix pursuit (OR1MP) algorithm is employed to minimize the low-rank constraint of the block Hankel matrix. In the new algorithm, only the left and right top singular vectors are needed to be computed, thereby, avoiding the complexity of computation required for SVD. Thus, we improve the calculation efficiency significantly. Finally, we anti-average the rank-reduction block Hankel matrix and obtain the reconstructed data in the frequency domain. Numerical experiments on 3D seismic data show that the proposed interpolation algorithm provides much better performance than the traditional MSSA algorithm in computational speed, especially for large-scale data processing.
A spectral, quasi-cylindrical and dispersion-free Particle-In-Cell algorithm
Lehe, Remi; Andriyash, Igor A; Godfrey, Brendan B; Vay, Jean-Luc
2015-01-01
We propose a spectral Particle-In-Cell (PIC) algorithm that is based on the combination of a Hankel transform and a Fourier transform. For physical problems that have close-to-cylindrical symmetry, this algorithm can be much faster than full 3D PIC algorithms. In addition, unlike standard finite-difference PIC codes, the proposed algorithm is free of numerical dispersion. This algorithm is benchmarked in several situations that are of interest for laser-plasma interactions. These benchmarks show that it avoids a number of numerical artifacts, that would otherwise affect the physics in a standard PIC algorithm - including the zero-order numerical Cherenkov effect.
Novel Adaptive Beamforming Algorithm Based on Wavelet Packet Transform
Zhang Xiaofei; Xu Dazhuan
2005-01-01
An analysis of the received signal of array antennas shows that the received signal has multi-resolution characteristics, and hence the wavelet packet theory can be used to detect the signal. By emplying wavelet packet theory to adaptive beamforming, a wavelet packet transform-based adaptive beamforming algorithm (WP-ABF) is proposed . This WP-ABF algorithm uses wavelet packet transform as the preprocessing, and the wavelet packet transformed signal uses least mean square algorithm to implement the adaptive beamforming. White noise can be wiped off under wavelet packet transform according to the different characteristics of signal and white under the wavelet packet transform. Theoretical analysis and simulations demonstrate that the proposed WP-ABF algorithm converges faster than the conventional adaptive beamforming algorithm and the wavelet transform-based beamforming algorithm. Simulation results also reveal that the convergence of the algorithm relates closely to the wavelet base and series; that is, the algorithm convergence gets better with the increasing of series, and for the same series of wavelet base the convergence gets better with the increasing of regularity.
A TRANSFORMATION PATH ALGORITHM FOR UNCONSTRAINED SIGNOMIAL GEOMETRIC PROGRAMMING
王燕军; 张可村
2004-01-01
In this paper we present a transformation path algorithm for Unconstrained Signomial Geometric Programming (USGP). The algorithm is proposed from a new point of view based on exploring the characteristics of USGP problem. Firstly by some stable transformations, a particular subproblem is derived which is very easy to solve.Secondly, a special path is formed conveniently. And then the step of the algorithm consists in finding a "good" point to the current iterate by choosing it along the special path and within a trust region. It is proved that the algorithm is globally convergent.
Gerchberg-Papoulis algorithm and the finite Zak transform
Brodzik, Andrzej K.; Tolimieri, Richard
2000-12-01
We propose a new, time-frequency formulation of the Gerchberg-Papoulis algorithm for extrapolation of band- limited signals. The new formulation is obtained by translating the constituent operations of the Gerchberg- Papoulis procedure, the truncation and the Fourier transform, into the language of the finite Zak transform, a time-frequency tool intimately related to the Fourier transform. We will show that the use of the Zak transform results in a significant reduction of the computational complexity of the Gerchberg-Papoulis procedure and in an increased flexibility of the algorithm.
A fast butterfly algorithm for generalized Radon transforms
Hu, Jingwei
2013-06-21
Generalized Radon transforms, such as the hyperbolic Radon transform, cannot be implemented as efficiently in the frequency domain as convolutions, thus limiting their use in seismic data processing. We have devised a fast butterfly algorithm for the hyperbolic Radon transform. The basic idea is to reformulate the transform as an oscillatory integral operator and to construct a blockwise lowrank approximation of the kernel function. The overall structure follows the Fourier integral operator butterfly algorithm. For 2D data, the algorithm runs in complexity O(N2 log N), where N depends on the maximum frequency and offset in the data set and the range of parameters (intercept time and slowness) in the model space. From a series of studies, we found that this algorithm can be significantly more efficient than the conventional time-domain integration. © 2013 Society of Exploration Geophysicists.
Fuzzy Algorithm for Power Transformer Diagnostics
Nitin K. Dhote
2013-01-01
Full Text Available Dissolved gas analysis (DGA of transformer oil has been one of the most reliable techniques to detect the incipient faults. Many conventional DGA methods have been developed to interpret DGA results obtained from gas chromatography. Although these methods are widely used in the world, they sometimes fail to diagnose, especially when DGA results fall outside conventional methods codes or when more than one fault exist in the transformer. To overcome these limitations, the fuzzy inference system (FIS is proposed. Two hundred different cases are used to test the accuracy of various DGA methods in interpreting the transformer condition.
A VLSI architecture for simplified arithmetic Fourier transform algorithm
Reed, Irving S.; Shih, Ming-Tang; Truong, T. K.; Hendon, E.; Tufts, D. W.
1992-01-01
The arithmetic Fourier transform (AFT) is a number-theoretic approach to Fourier analysis which has been shown to perform competitively with the classical FFT in terms of accuracy, complexity, and speed. Theorems developed in a previous paper for the AFT algorithm are used here to derive the original AFT algorithm which Bruns found in 1903. This is shown to yield an algorithm of less complexity and of improved performance over certain recent AFT algorithms. A VLSI architecture is suggested for this simplified AFT algorithm. This architecture uses a butterfly structure which reduces the number of additions by 25 percent of that used in the direct method.
Commuting Quasihomogeneous Toeplitz Operator and Hankel Operator on Weighted Bergman Space
Jun Yang
2013-01-01
Full Text Available We characterize the commuting Toeplitz operator and Hankel operator with quasihomogeneous symbols. Also, we use it to show the necessary and sufficient conditions for commuting Toeplitz operator and Hankel operator with ordinary functions.
A general algorithm for computing distance transforms in linear time
Meijster, A.; Roerdink, J.B.T.M.; Hesselink, W.H.; Goutsias, J; Vincent, L; Bloomberg, DS
2000-01-01
A new general algorithm fur computing distance transforms of digital images is presented. The algorithm consists of two phases. Both phases consist of two scans, a forward and a backward scan. The first phase scans the image column-wise, while the second phase scans the image row-wise. Since the com
A general algorithm for computing distance transforms in linear time
Meijster, A.; Roerdink, J.B.T.M.; Hesselink, W.H.; Goutsias, J; Vincent, L; Bloomberg, DS
2000-01-01
A new general algorithm fur computing distance transforms of digital images is presented. The algorithm consists of two phases. Both phases consist of two scans, a forward and a backward scan. The first phase scans the image column-wise, while the second phase scans the image row-wise. Since the
A linear-time algorithm for Euclidean feature transform sets
Hesselink, Wim H.
2007-01-01
The Euclidean distance transform of a binary image is the function that assigns to every pixel the Euclidean distance to the background. The Euclidean feature transform is the function that assigns to every pixel the set of background pixels with this distance. We present an algorithm to compute the
The Watershed Transform : Definitions, Algorithms and Parallelization Strategies
Roerdink, Jos B.T.M.; Meijster, Arnold
2000-01-01
The watershed transform is the method of choice for image segmentation in the field of mathematical morphology. We present a critical review of several definitions of the watershed transform and the associated sequential algorithms, and discuss various issues which often cause confusion in the liter
Image compression algorithm using wavelet transform
Cadena, Luis; Cadena, Franklin; Simonov, Konstantin; Zotin, Alexander; Okhotnikov, Grigory
2016-09-01
Within the multi-resolution analysis, the study of the image compression algorithm using the Haar wavelet has been performed. We have studied the dependence of the image quality on the compression ratio. Also, the variation of the compression level of the studied image has been obtained. It is shown that the compression ratio in the range of 8-10 is optimal for environmental monitoring. Under these conditions the compression level is in the range of 1.7 - 4.2, depending on the type of images. It is shown that the algorithm used is more convenient and has more advantages than Winrar. The Haar wavelet algorithm has improved the method of signal and image processing.
Automatic Image Registration Algorithm Based on Wavelet Transform
LIU Qiong; NI Guo-qiang
2006-01-01
An automatic image registration approach based on wavelet transform is proposed. This proposed method utilizes multiscale wavelet transform to extract feature points. A coarse-to-fine feature matching method is utilized in the feature matching phase. A two-way matching method based on cross-correlation to get candidate point pairs and a fine matching based on support strength combine to form the matching algorithm. At last, based on an affine transformation model, the parameters are iteratively refined by using the least-squares estimation approach. Experimental results have verified that the proposed algorithm can realize automatic registration of various kinds of images rapidly and effectively.
New homotopy analysis transform algorithm to solve volterra integral equation
Sunil Kumar
2014-03-01
Full Text Available The main aim of the present work is to propose a new and simple algorithm for Volterra integral equation arising in demography, the study of viscoelastic materials, and in insurance mathematics through the renewal equation by using homotopy analysis transform method. The homotopy analysis transform method is an innovative adjustment in Laplace transform algorithm and makes the calculation much simpler. The solutions obtained by proposed method indicate that the approach is easy to implement and computationally very attractive. The beauty of the paper is coupling of two techniques. Finally, two numerical examples are given to show the accuracy and stability of this method.
Face Recognition Algorithms Based on Transformed Shape Features
Sambhunath Biswas
2012-05-01
Full Text Available Human face recognition is, indeed, a challenging task, especially under illumination and pose variations. We examine in the present paper effectiveness of two simple algorithms using coiflet packet and Radon transforms to recognize human faces from some databases of still gray level images, under the environment of illumination and pose variations. Both the algorithms convert 2-D gray level training face images into their respective depth maps or physical shape which are subsequently transformed by Coiflet packet and Radon transforms to compute energy for feature extraction. Experiments show that such transformed shape features are robust to illumination and pose variations. With the features extracted, training classes are optimally separated through linear discriminant analysis (LDA, while classification for test face images is made through a k-NN classifier, based on L1 norm and Mahalanobis distance measures. Proposed algorithms are then tested on face images that differ in illumination,expression or pose separately, obtained from three databases,namely, ORL, Yale and Essex-Grimace databases. Results, so obtained, are compared with two different existing algorithms.Performance using Daubechies wavelets is also examined. It is seen that the proposed Coiflet packet and Radon transform based algorithms have significant performance, especially under different illumination conditions and pose variation. Comparison shows the proposed algorithms are superior.
Fast Wavelet Transform Algorithms With Low Memory Requirements
Maya Babuji
2010-06-01
Full Text Available In this paper, a new algorithm to efficiently compute the two-dimensional wavelet transform is presented. This algorithm aims at low memory consumption and reduced complexity, meeting these requirements by means of line-by-line processing. In this proposal,we use recursion to automatically place the order in which the wavelet transform is computed. This way, we solve some synchronization problems that have not been tackled byprevious proposals. Furthermore, unlike other similar proposals, our proposal can be straightforwardly implemented from the algorithm description. To this end, a general algorithm is given which is further detailed to allow its implementation with a simple filterbank or using the more efficient lifting scheme. We also include a new fast run-length encoder to be used along with the proposed wavelet transform for fast image compression and reduced memory consumption.
Parallel transformation of K-SVD solar image denoising algorithm
Liang, Youwen; Tian, Yu; Li, Mei
2017-02-01
The images obtained by observing the sun through a large telescope always suffered with noise due to the low SNR. K-SVD denoising algorithm can effectively remove Gauss white noise. Training dictionaries for sparse representations is a time consuming task, due to the large size of the data involved and to the complexity of the training algorithms. In this paper, an OpenMP parallel programming language is proposed to transform the serial algorithm to the parallel version. Data parallelism model is used to transform the algorithm. Not one atom but multiple atoms updated simultaneously is the biggest change. The denoising effect and acceleration performance are tested after completion of the parallel algorithm. Speedup of the program is 13.563 in condition of using 16 cores. This parallel version can fully utilize the multi-core CPU hardware resources, greatly reduce running time and easily to transplant in multi-core platform.
Scale transform algorithm used in FMCW SAR data processing
Jiang Zhihong; Kan Huangfu; Wan Jianwei
2007-01-01
The frequency-modulated continuous-wave (FMCW) synthetic aperture radar (SAR) is a light-weight,cost-effective, high-resolution imaging radar, which is suitable for a small flight platform. The signal model is derived for FMCW SAR used in unmanned aerial vehicles (UAV) reconnaissance and remote sensing. An appropriate algorithm is proposed. The algorithm performs the range cell migration correction (RCMC) for continuous nonchirped raw data using the energy invariance of the scaling of a signal in the scale domain. The azimuth processing is based on step transform without geometric resampling operation. The complete derivation of the algorithm is presented. The algorithm performance is shown by simulation results.
Optimal Hankel Norm Model Reduction by Truncation of Trajectories
Roorda, B.; Weiland, S.
2000-01-01
We show how optimal Hankel-norm approximations of dynamical systems allow for a straightforward interpretation in terms of system trajectories. It is shown that for discrete time single-input systems optimal reductions are obtained by cutting 'balanced trajectories', i.e., by disconnecting the past
Discrete cosine transform algorithms, advantages, applications
Rao, K R
1990-01-01
This is the first comprehensive treatment of the theoretical aspects of the discrete cosine transform (DCT), which is being recommended by various standards organizations, such as the CCITT, ISO etc., as the primary compression tool in digital image coding. The main purpose of the book is to provide a complete source for the user of this signal processing tool, where both the basics and the applications are detailed. An extensive bibliography covers both the theory and applications of the DCT. The novice will find the book useful in its self-contained treatment of the theory of the DCT, the de
The efficient algorithms for achieving Euclidean distance transformation.
Shih, Frank Y; Wu, Yi-Ta
2004-08-01
Euclidean distance transformation (EDT) is used to convert a digital binary image consisting of object (foreground) and nonobject (background) pixels into another image where each pixel has a value of the minimum Euclidean distance from nonobject pixels. In this paper, the improved iterative erosion algorithm is proposed to avoid the redundant calculations in the iterative erosion algorithm. Furthermore, to avoid the iterative operations, the two-scan-based algorithm by a deriving approach is developed for achieving EDT correctly and efficiently in a constant time. Besides, we discover when obstacles appear in the image, many algorithms cannot achieve the correct EDT except our two-scan-based algorithm. Moreover, the two-scan-based algorithm does not require the additional cost of preprocessing or relative-coordinates recording.
Fingerprint Image Segmentation Algorithm Based on Contourlet Transform Technology
Guanghua Zhang
2016-09-01
Full Text Available This paper briefly introduces two classic algorithms for fingerprint image processing, which include the soft threshold denoise algorithm of wavelet domain based on wavelet domain and the fingerprint image enhancement algorithm based on Gabor function. Contourlet transform has good texture sensitivity and can be used for the segmentation enforcement of the fingerprint image. The method proposed in this paper has attained the final fingerprint segmentation image through utilizing a modified denoising for a high-frequency coefficient after Contourlet decomposition, highlighting the fingerprint ridge line through modulus maxima detection and finally connecting the broken fingerprint line using a value filter in direction. It can attain richer direction information than the method based on wavelet transform and Gabor function and can make the positioning of detailed features more accurate. However, its ridge should be more coherent. Experiments have shown that this algorithm is obviously superior in fingerprint features detection.
A Matrix Formulation of Discrete Chirp Fourier Transform Algorithms
Juan Pablo Soto Quiros; Domingo Rodriguez
2014-01-01
This work presents a computational matrix framework in terms of tensor signal algebra for the formulation of discrete chirp Fourier transform algorithms. These algorithms are used in this work to estimate the point target functions (impulse response functions) of multiple-input multiple-output (MIMO) synthetic aperture radar (SAR) systems. This estimation technique is being studied as an alternative to the estimation of point target functions using the discrete cross-ambiguity function for certain types of environmental surveillance applications. The tensor signal algebra is presented as a mathematics environment composed of signal spaces, finite dimensional linear operators, and special matrices where algebraic methods are used to generate these signal transforms as computational estimators. Also, the tensor signal algebra contributes to analysis, design, and implementation of parallel algorithms. An instantiation of the framework was performed by using the MATLAB Parallel Computing Toolbox, where all the algorithms presented in this paper were implemented.
OPTIMAL DESIGN OF SINGLE PHASE TRANSFORMER USING BACTERIAL FORAGING ALGORITHM
S.SUBRAMANIAN,
2011-04-01
Full Text Available The aim of the transformer design is to obtain the dimensions of all the parts of the transformer based on the given specification, using available materials economically in order to achieve lower cost,reduced size and better operating performance. In this paper, the task of finding optimal design of single phase transformer has been formulated as nonlinear programming problem, so as to meet thespecification with the minimum cost and improve the efficiency. Four independent variables and two constraints are taken to meet the requirement of the design. The method utilizes Bacterial ForagingAlgorithm (BFA to provide optimum design of single phase transformer. The validity of the proposed method has been tested on a sample transformer and the simulation results obtained are compared with conventional method and Particle Swarm Optimization (PSO technique. The simulation results reveal that the proposed scheme determines the optimal variables of transformer along with the performance parameters efficiently.
Discrete Hadamard transformation algorithm's parallelism analysis and achievement
Hu, Hui
2009-07-01
With respect to Discrete Hadamard Transformation (DHT) wide application in real-time signal processing while limitation in operation speed of DSP. The article makes DHT parallel research and its parallel performance analysis. Based on multiprocessor platform-TMS320C80 programming structure, the research is carried out to achieve two kinds of parallel DHT algorithms. Several experiments demonstrated the effectiveness of the proposed algorithms.
AN ADVANCED SCALE INVARIANT FEATURE TRANSFORM ALGORITHM FOR FACE RECOGNITION
Mohammad Mohsen Ahmadinejad; Elizabeth Sherly
2016-01-01
In computer vision, Scale-invariant feature transform (SIFT) algorithm is widely used to describe and detect local features in images due to its excellent performance. But for face recognition, the implementation of SIFT was complicated because of detecting false key-points in the face image due to irrelevant portions like hair style and other background details. This paper proposes an algorithm for face recognition to improve recognition accuracy by selecting relevant SIFT key-points only th...
Solving SAT by Algorithm Transform of Wu‘s Method
贺思敏; 张钹
1999-01-01
Recently algorithms for solving propositional satisfiability problem, or SAT,have aroused great interest,and more attention has been paid to transformation problem solving.The commonly used transformation is representation transform,but since its intermediate computing procedure is a black box from the viewpoint of the original problem,this approach has many limitations.In this paper,a new approach called algorithm transform is proposed and applied to solving SAT by Wu's method,a general algorithm for solving polynomial equations.B y establishing the correspondence between the primitive operation in Wu's method and clause resolution is SAT,it is shown that Wu's method,when used for solving SAT,,is primarily a restricted clause resolution procedure.While Wu's method introduces entirely new concepts.e.g.characteristic set of clauses,to resolution procedure,the complexity result of resolution procedure suggests an exponential lower bound to Wu's method for solving general polynomial equations.Moreover,this algorithm transform can help achieve a more efficient implementation of Wu's method since it can avoid the complex manipulation of polynomials and can make the best use of domain specific knowledge.
Adaptive wavelet transform algorithm for image compression applications
Pogrebnyak, Oleksiy B.; Manrique Ramirez, Pablo
2003-11-01
A new algorithm of locally adaptive wavelet transform is presented. The algorithm implements the integer-to-integer lifting scheme. It performs an adaptation of the wavelet function at the prediction stage to the local image data activity. The proposed algorithm is based on the generalized framework for the lifting scheme that permits to obtain easily different wavelet coefficients in the case of the (N~,N) lifting. It is proposed to perform the hard switching between (2, 4) and (4, 4) lifting filter outputs according to an estimate of the local data activity. When the data activity is high, i.e., in the vicinity of edges, the (4, 4) lifting is performed. Otherwise, in the plain areas, the (2,4) decomposition coefficients are calculated. The calculations are rather simples that permit the implementation of the designed algorithm in fixed point DSP processors. The proposed adaptive transform possesses the perfect restoration of the processed data and possesses good energy compactation. The designed algorithm was tested on different images. The proposed adaptive transform algorithm can be used for image/signal lossless compression.
A Reversible Image Steganographic Algorithm Based on Slantlet Transform
Sushil Kumar
2013-07-01
Full Text Available In this paper we present a reversible imagesteganography technique based on Slantlet transform (SLTand using advanced encryption standard (AES method. Theproposed method first encodes the message using two sourcecodes, viz., Huffman codes and a self-synchronizing variablelength code known as, T-code. Next, the encoded binarystring is encrypted using an improved AES method. Theencrypted data so obtained is embedded in the middle andhigh frequency sub-bands, obtained by applying 2-level ofSLT to the cover-image, using thresholding method. Theproposed algorithm is compared with the existing techniquesbased on wavelet transform. The Experimental results showthat the proposed algorithm can extract hidden message andrecover the original cover image with low distortion. Theproposed algorithm offers acceptable imperceptibility,security (two-layer security and provides robustness againstGaussian and Salt-n-Pepper noise attack.
Radix-3 Algorithm for Realization of Discrete Fourier Transform
M.Narayan Murty
2016-07-01
Full Text Available In this paper, a new radix-3 algorithm for realization of discrete Fourier transform (DFT of length N = 3m (m = 1, 2, 3,... is presented. The DFT of length N can be realized from three DFT sequences, each of length N/3. If the input signal has length N, direct calculation of DFT requires O (N 2 complex multiplications (4N 2 real multiplications and some additions. This radix-3 algorithm reduces the number of multiplications required for realizing DFT. For example, the number of complex multiplications required for realizing 9-point DFT using the proposed radix-3 algorithm is 60. Thus, saving in time can be achieved in the realization of proposed algorithm.
Adaptive wavelet transform algorithm for lossy image compression
Pogrebnyak, Oleksiy B.; Ramirez, Pablo M.; Acevedo Mosqueda, Marco Antonio
2004-11-01
A new algorithm of locally adaptive wavelet transform based on the modified lifting scheme is presented. It performs an adaptation of the wavelet high-pass filter at the prediction stage to the local image data activity. The proposed algorithm uses the generalized framework for the lifting scheme that permits to obtain easily different wavelet filter coefficients in the case of the (~N, N) lifting. Changing wavelet filter order and different control parameters, one can obtain the desired filter frequency response. It is proposed to perform the hard switching between different wavelet lifting filter outputs according to the local data activity estimate. The proposed adaptive transform possesses a good energy compaction. The designed algorithm was tested on different images. The obtained simulation results show that the visual and quantitative quality of the restored images is high. The distortions are less in the vicinity of high spatial activity details comparing to the non-adaptive transform, which introduces ringing artifacts. The designed algorithm can be used for lossy image compression and in the noise suppression applications.
Digital Watermarking Algorithm Based on Wavelet Transform and Neural Network
WANG Zhenfei; ZHAI Guangqun; WANG Nengchao
2006-01-01
An effective blind digital watermarking algorithm based on neural networks in the wavelet domain is presented. Firstly, the host image is decomposed through wavelet transform. The significant coefficients of wavelet are selected according to the human visual system (HVS) characteristics. Watermark bits are added to them. And then effectively cooperates neural networks to learn the characteristics of the embedded watermark related to them. Because of the learning and adaptive capabilities of neural networks, the trained neural networks almost exactly recover the watermark from the watermarked image. Experimental results and comparisons with other techniques prove the effectiveness of the new algorithm.
Fractional Transforms in Optical Information Processing
Maria Luisa Calvo
2005-06-01
Full Text Available We review the progress achieved in optical information processing during the last decade by applying fractional linear integral transforms. The fractional Fourier transform and its applications for phase retrieval, beam characterization, space-variant pattern recognition, adaptive filter design, encryption, watermarking, and so forth is discussed in detail. A general algorithm for the fractionalization of linear cyclic integral transforms is introduced and it is shown that they can be fractionalized in an infinite number of ways. Basic properties of fractional cyclic transforms are considered. The implementation of some fractional transforms in optics, such as fractional Hankel, sine, cosine, Hartley, and Hilbert transforms, is discussed. New horizons of the application of fractional transforms for optical information processing are underlined.
An Efficient Algorithm for Query Transformation in Semantic Query Optimization
无
2002-01-01
Semantic query optimization (SQO) is comparatively a recent approach for the transformation of given query into equivalent alternative query using matching rules in order to select an optimal query based on the costs of executing alternative queries. The key aspect of the algorithm proposed here is that previous proposed SQO techniques can be considered equally in the uniform cost model, with which optimization opportunities will not be missed. At the same time, the authors used the implication closure to guarantee that any matched rule will not be lost. The authors implemented their algorithm for the optimization of decomposed sub-query in local database in Multi-Database Integrator (MDBI), which is a multidatabase project. The experimental results verify that this algorithm is effective in the process of SQO.
Yu, Alfred C H; Cobbold, Richard S C
2008-03-01
Because of their adaptability to the slow-time signal contents, eigen-based filters have shown potential in improving the flow detection performance of color flow images. This paper proposes a new eigen-based filter called the Hankel-SVD filter that is intended to process each slowtime ensemble individually. The new filter is derived using the notion of principal Hankel component analysis, and it achieves clutter suppression by retaining only the principal components whose order is greater than the clutter eigen-space dimension estimated from a frequency based analysis algorithm. To assess its efficacy, the Hankel-SVD filter was first applied to synthetic slow-time data (ensemble size: 10) simulated from two different sets of flow parameters that model: 1) arterial imaging (blood velocity: 0 to 38.5 cm/s, tissue motion: up to 2 mm/s, transmit frequency: 5 MHz, pulse repetition period: 0.4 ms) and 2) deep vessel imaging (blood velocity: 0 to 19.2 cm/s, tissue motion: up to 2 cm/s, transmit frequency: 2 MHz, pulse repetition period: 2.0 ms). In the simulation analysis, the post-filter clutter-to- blood signal ratio (CBR) was computed as a function of blood velocity. Results show that for the same effective stopband size (50 Hz), the Hankel-SVD filter has a narrower transition region in the post-filter CBR curve than that of another type of adaptive filter called the clutter-downmixing filter. The practical efficacy of the proposed filter was tested by application to in vivo color flow data obtained from the human carotid arteries (transmit frequency: 4 MHz, pulse repetition period: 0.333 ms, ensemble size: 10). The resulting power images show that the Hankel-SVD filter can better distinguish between blood and moving-tissue regions (about 9 dB separation in power) than the clutter-downmixing filter and a fixed-rank multi ensemble-based eigen-filter (which showed a 2 to 3 dB separation).
Iris Localization Algorithm Based on Improved Generalized Symmetry Transform
左坤隆; 刘文耀; 朱昊; 王晓东
2004-01-01
Accuracy and fastness of iris localization are very important in automatic iris recognition. A new fast iris localization algorithm based on improved generalized symmetry transform (GST) was proposed by utilizing iris symmetry. GST was improved in three aspects:1) A new distance weight function is defined. The new weight function, which is effective in iris localization, utilized the characteristic of irises that the iris is a circular object and it has one inner boundary and one outer boundary. 2) Each calculation of the symmetry measurement of a pair of symmetry points was performed by taking one point of a pair as the starting point of the transformation. This is the most important reason for fast iris localization,due to which, repetitious computation was largely excluded. 3) A new phase weight function was proposed to adjust GST to locate circle target much better because the inner part of iris is darker than the outer part. The edge map of iris image was acquired and GST was only implemented on the edge point, which decreased computation without loss of accuracy. The modification of distance weight function and phase weight function leads to the accuracy of localization, and other ideas speed up the localization. Experiments show that the average speed of new algorithm is about 7.0-8.5 times as high as traditional ones including integro-differential operator and Hough transform method.
A Streaming Distance Transform Algorithm for Neighborhood-Sequence Distances
Nicolas Normand
2014-09-01
Full Text Available We describe an algorithm that computes a “translated” 2D Neighborhood-Sequence Distance Transform (DT using a look up table approach. It requires a single raster scan of the input image and produces one line of output for every line of input. The neighborhood sequence is specified either by providing one period of some integer periodic sequence or by providing the rate of appearance of neighborhoods. The full algorithm optionally derives the regular (centered DT from the “translated” DT, providing the result image on-the-ﬂy, with a minimal delay, before the input image is fully processed. Its efficiency can benefit all applications that use neighborhood- sequence distances, particularly when pipelined processing architectures are involved, or when the size of objects in the source image is limited.
A Steganographic Method Based on Integer Wavelet Transform & Genatic Algorithm
Preeti Arora
2014-05-01
Full Text Available The proposed system presents a novel approach of building a secure data hiding technique of steganography using inverse wavelet transform along with Genetic algorithm. The prominent focus of the proposed work is to develop RS-analysis proof design with higest imperceptibility. Optimal Pixal Adjustment process is also adopted to minimize the difference error between the input cover image and the embedded-image and in order to maximize the hiding capacity with low distortions respectively. The analysis is done for mapping function, PSNR, image histogram, and parameter of RS analysis. The simulation results highlights that the proposed security measure basically gives better and optimal results in comparison to prior research work conducted using wavelets and genetic algorithm.
Remote Sensing Image Resolution Enlargement Algorithm Based on Wavelet Transformation
Samiul Azam
2014-05-01
Full Text Available In this paper, we present a new image resolution enhancement algorithm based on cycle spinning and stationary wavelet subband padding. The proposed technique or algorithm uses stationary wavelet transformation (SWT to decompose the low resolution (LR image into frequency subbands. All these frequency subbands are interpolated using either bicubic or lanczos interpolation, and these interpolated subbands are put into inverse SWT process for generating intermediate high resolution (HR image. Finally, cycle spinning (CS is applied on this intermediate high resolution image for reducing blocking artifacts, followed by, traditional Laplacian sharpening filter is used to make the generated high resolution image sharper. This new technique has been tested on several satellite images. Experimental result shows that the proposed technique outperforms the conventional and the state-of-the-art techniques in terms of peak signal to noise ratio, root mean square error, entropy, as well as, visual perspective.
A New Shape-Coding Algorithm by Using Wavelet Transform
石旭利; 张兆杨
2003-01-01
In this paper, we propose a new shape-coding algorithm called wavelet-based shape coding (WBSC). Performing wavelet transform on the orientation of original planar curve gives the corners called corner-1 points and end of arcs that belong to the original curve. Each arc is represented by a broken line and the corners called corner-2 points of the broken line are extracted. A polygonal approximation of a contour is an ordered list of corner-1 points, ends of arcs and corner-2 points which are extracted by using the above algorithm. All of the points are called polygonal vertices which will be compressed by our adaptive arithmetic encoding. Experimental results show that our method reduces code bits by about 26% compared with the context-based arithmetic encoding (CAE) of MPEG-4, and the subjective quality of the reconstructed shape is better than that of CAE at the same Dn.
Image recombination transform algorithm for superresolution structured illumination microscopy
Zhou, Xing; Lei, Ming; Dan, Dan; Yao, Baoli; Yang, Yanlong; Qian, Jia; Chen, Guangde; Bianco, Piero R.
2016-09-01
Structured illumination microscopy (SIM) is an attractive choice for fast superresolution imaging. The generation of structured illumination patterns made by interference of laser beams is broadly employed to obtain high modulation depth of patterns, while the polarizations of the laser beams must be elaborately controlled to guarantee the high contrast of interference intensity, which brings a more complex configuration for the polarization control. The emerging pattern projection strategy is much more compact, but the modulation depth of patterns is deteriorated by the optical transfer function of the optical system, especially in high spatial frequency near the diffraction limit. Therefore, the traditional superresolution reconstruction algorithm for interference-based SIM will suffer from many artifacts in the case of projection-based SIM that possesses a low modulation depth. Here, we propose an alternative reconstruction algorithm based on image recombination transform, which provides an alternative solution to address this problem even in a weak modulation depth. We demonstrated the effectiveness of this algorithm in the multicolor superresolution imaging of bovine pulmonary arterial endothelial cells in our developed projection-based SIM system, which applies a computer controlled digital micromirror device for fast fringe generation and multicolor light-emitting diodes for illumination. The merit of the system incorporated with the proposed algorithm allows for a low excitation intensity fluorescence imaging even less than 1 W/cm2, which is beneficial for the long-term, in vivo superresolved imaging of live cells and tissues.
The discrete Fourier transform theory, algorithms and applications
Sundaraajan, D
2001-01-01
This authoritative book provides comprehensive coverage of practical Fourier analysis. It develops the concepts right from the basics and gradually guides the reader to the advanced topics. It presents the latest and practically efficient DFT algorithms, as well as the computation of discrete cosine and Walsh-Hadamard transforms. The large number of visual aids such as figures, flow graphs and flow charts makes the mathematical topic easy to understand. In addition, the numerous examples and the set of C-language programs (a supplement to the book) help greatly in understanding the theory and
Multi-resolution inversion algorithm for the attenuated radon transform
Barbano, Paolo Emilio
2011-09-01
We present a FAST implementation of the Inverse Attenuated Radon Transform which incorporates accurate collimator response, as well as artifact rejection due to statistical noise and data corruption. This new reconstruction procedure is performed by combining a memory-efficient implementation of the analytical inversion formula (AIF [1], [2]) with a wavelet-based version of a recently discovered regularization technique [3]. The paper introduces all the main aspects of the new AIF, as well numerical experiments on real and simulated data. Those display a substantial improvement in reconstruction quality when compared to linear or iterative algorithms. © 2011 IEEE.
Far-field radiation patterns of aperture antennas by the Winograd Fourier transform algorithm
Heisler, R.
1978-01-01
A more time-efficient algorithm for computing the discrete Fourier transform, the Winograd Fourier transform (WFT), is described. The WFT algorithm is compared with other transform algorithms. Results indicate that the WFT algorithm in antenna analysis appears to be a very successful application. Significant savings in cpu time will improve the computer turn around time and circumvent the need to resort to weekend runs.
TRANSFORMATION ALGORITHM FOR IMAGES OBTAINED BY OMNIDIRECTIONAL CAMERAS
V. P. Lazarenko
2015-01-01
Full Text Available Omnidirectional optoelectronic systems find their application in areas where a wide viewing angle is critical. However, omnidirectional optoelectronic systems have a large distortion that makes their application more difficult. The paper compares the projection functions of traditional perspective lenses and omnidirectional wide angle fish-eye lenses with a viewing angle not less than 180°. This comparison proves that distortion models of omnidirectional cameras cannot be described as a deviation from the classic model of pinhole camera. To solve this problem, an algorithm for transforming omnidirectional images has been developed. The paper provides a brief comparison of the four calibration methods available in open source toolkits for omnidirectional optoelectronic systems. Geometrical projection model is given used for calibration of omnidirectional optical system. The algorithm consists of three basic steps. At the first step, we calculate he field of view of a virtual pinhole PTZ camera. This field of view is characterized by an array of 3D points in the object space. At the second step the array of corresponding pixels for these three-dimensional points is calculated. Then we make a calculation of the projection function that expresses the relation between a given 3D point in the object space and a corresponding pixel point. In this paper we use calibration procedure providing the projection function for calibrated instance of the camera. At the last step final image is formed pixel-by-pixel from the original omnidirectional image using calculated array of 3D points and projection function. The developed algorithm gives the possibility for obtaining an image for a part of the field of view of an omnidirectional optoelectronic system with the corrected distortion from the original omnidirectional image. The algorithm is designed for operation with the omnidirectional optoelectronic systems with both catadioptric and fish-eye lenses
A hyperspectral images compression algorithm based on 3D bit plane transform
Zhang, Lei; Xiang, Libin; Zhang, Sam; Quan, Shengxue
2010-10-01
According the analyses of the hyper-spectral images, a new compression algorithm based on 3-D bit plane transform is proposed. The spectral coefficient is higher than the spatial. The algorithm is proposed to overcome the shortcoming of 1-D bit plane transform for it can only reduce the correlation when the neighboring pixels have similar values. The algorithm calculates the horizontal, vertical and spectral bit plane transform sequentially. As the spectral bit plane transform, the algorithm can be easily realized by hardware. In addition, because the calculation and encoding of the transform matrix of each bit are independent, the algorithm can be realized by parallel computing model, which can improve the calculation efficiency and save the processing time greatly. The experimental results show that the proposed algorithm achieves improved compression performance. With a certain compression ratios, the algorithm satisfies requirements of hyper-spectral images compression system, by efficiently reducing the cost of computation and memory usage.
Third Hankel determinant for the inverse of reciprocal of bounded turning functions
B. Venkateswarlu
2016-04-01
Full Text Available In this paper we obtain the best possible upper bound to the third Hankel determinants for the functions belonging to the class of reciprocal of bounded turning functions using Toeplitz determinants.
Practical implementation of Hilbert-Huang Transform algorithm
黄大吉; 赵进平; 苏纪兰
2003-01-01
Hilbert-Huang Transform (HHT) is a newly developed powerful method for nonlinearand non-stationary time series analysis. The empirical mode decomposition is the key part of HHT,while its algorithm was protected by NASA as a US patent, which limits the wide application among thescientific community. Two approaches, mirror periodic and extrema extending methods, have been de-veloped for handling the end effects of empirical mode decomposition. The implementation of the HHT isrealized in detail to widen the application. The detailed comparison of the results from two methods withthat from Huang et al. (1998, 1999), and the comparison between two methods are presented. Gener-ally, both methods reproduce faithful results as those of Huang et al. For mirror periodic method(MPM), the data are extended once forever. Ideally, it is a way for handling the end effects of theHHT, especially for the signal that has symmetric waveform. The extrema extending method (EEM)behaves as good as MPM, and it is better than MPM for the signal that has strong asymmetric wave-form. However, it has to perform extrema envelope extending in every shifting process.
A new fast algorithm for computing a complex number: Theoretic transforms
Reed, I. S.; Liu, K. Y.; Truong, T. K.
1977-01-01
A high-radix fast Fourier transformation (FFT) algorithm for computing transforms over GF(sq q), where q is a Mersenne prime, is developed to implement fast circular convolutions. This new algorithm requires substantially fewer multiplications than the conventional FFT.
Image Transformation using Modified Kmeans clustering algorithm for Parallel saliency map
Aman Sharma
2013-08-01
Full Text Available to design an image transformation system is Depending on the transform chosen, the input and output images may appear entirely different and have different interpretations. Image Transformationwith the help of certain module like input image, image cluster index, object in cluster and color index transformation of image. K-means clustering algorithm is used to cluster the image for bettersegmentation. In the proposed method parallel saliency algorithm with K-means clustering is used to avoid local minima and to find the saliency map. The region behind that of using parallel saliency algorithm is proved to be more than exiting saliency algorithm.
Speckle reduction algorithm for laser underwater image based on curvelet transform
Wei Ni; Baolong Guo; Liu Yang; Peiyan Fei
2006-01-01
@@ Based on the analysis on the statistical model of speckle noise in laser underwater image, a novel speckle reduction algorithm using curvelet transform is proposed. Logarithmic transform is performed to transform the original multiplicative speckle noise into additive noise. An improved hard thresholding algorithm is applied in curvelet transform domain. The classical Monte-Carlo method is adopted to estimate the statistics of contourlet coefficients for speckle noise, thus determining the optimal threshold set. To further improve the visual quality of despeckling laser image, the cycle spinning technique is also utilized. Experimental results show that the proposed algorithm can achieve better performance than classical wavelet method and maintain more detail information.
Implementation of Period-Finding Algorithm by Means of Simulating Quantum Fourier Transform
Zohreh Moghareh Abed
2010-01-01
Full Text Available In this paper, we introduce quantum fourier transform as a key ingredient for many useful algorithms. These algorithms make a solution for problems which is considered to be intractable problems on a classical computer. Quantum Fourier transform is propounded as a key for quantum phase estimation algorithm. In this paper our aim is the implementation of period-finding algorithm.Quantum computer solves this problem, exponentially faster than classical one. Quantum phase estimation algorithm is the key for the period-finding problem .Therefore, by means of simulating quantum Fourier transform, we are able to implement the period-finding algorithm. In this paper, the simulation of quantum Fourier transform is carried out by Matlab software.
Faster fourier transformation: The algorithm of S. Winograd
Zohar, S.
1979-01-01
The new DFT algorithm of S. Winograd is developed and presented in detail. This is an algorithm which uses about 1/5 of the number of multiplications used by the Cooley-Tukey algorithm and is applicable to any order which is a product of relatively prime factors from the following list: 2,3,4,5,7,8,9,16. The algorithm is presented in terms of a series of tableaus which are convenient, compact, graphical representations of the sequence of arithmetic operations in the corresponding parts of the algorithm. Using these in conjunction with included Tables makes it relatively easy to apply the algorithm and evaluate its performance.
Optical phase extraction algorithm based on the continuous wavelet and the Hilbert transforms
Bahich, Mustapha; Barj, Elmostafa
2010-01-01
In this paper we present an algorithm for optical phase evaluation based on the wavelet transform technique. The main advantage of this method is that it requires only one fringe pattern. This algorithm is based on the use of a second {\\pi}/2 phase shifted fringe pattern where it is calculated via the Hilbert transform. To test its validity, the algorithm was used to demodulate a simulated fringe pattern giving the phase distribution with a good accuracy.
张茁生; 刘贵忠; 刘峰
2003-01-01
A new algorithm for reconstructing a signal from its wavelet transform modulus maxima is presented based on an iterative method for solutions to monotone operator equations in Hilbert spaces. The algorithm's convergence is proved. Numerical simulations for different types of signals are given. The results indicate that compared with Mallat's alternate projection method, the proposed algorithm is sim-pler, faster and more effective.
Ogawa, Takahiro; Haseyama, Miki
2013-03-01
A missing texture reconstruction method based on an error reduction (ER) algorithm, including a novel estimation scheme of Fourier transform magnitudes is presented in this brief. In our method, Fourier transform magnitude is estimated for a target patch including missing areas, and the missing intensities are estimated by retrieving its phase based on the ER algorithm. Specifically, by monitoring errors converged in the ER algorithm, known patches whose Fourier transform magnitudes are similar to that of the target patch are selected from the target image. In the second approach, the Fourier transform magnitude of the target patch is estimated from those of the selected known patches and their corresponding errors. Consequently, by using the ER algorithm, we can estimate both the Fourier transform magnitudes and phases to reconstruct the missing areas.
Fast Fourier transform for Voigt profile: Comparison with some other algorithms
Abousahl, S.; Gourma, M.; Bickel, M.
1997-02-01
There are different algorithms describing the Voigt profile. This profile is encountered in many areas of physics which could be limited by the resolution of the instrumentation used to measure it and by other phenomena like the interaction between the emitted waves and matter. In nuclear measurement field, the codes used to characterise radionucleides rely on algorithms resolving the Voigt profile equation. The Fast Fourier Transform (FFT) algorithm allows the validation of some algorithms.
Fast and Parallel Spectral Transform Algorithms for Global Shallow Water Models
Jakob, Ruediger
1993-01-01
This dissertation examines spectral transform algorithms for the solution of the shallow water equations on the sphere and studies their implementation and performance on shared memory vector multiprocessors. Beginning with the standard spectral transform algorithm in vorticity divergence form and its implementation in the Fortran based parallel programming language Force, two modifications are researched. First, the transforms and matrices associated with the meridional derivatives of the associated Legendre functions are replaced by corresponding operations with the spherical harmonic coefficients. Second, based on the fast Fourier transform and the fast multipole method, a lower complexity algorithm is derived that uses fast transformations between Legendre and interior Fourier nodes, fast surface spherical truncation and a fast spherical Helmholtz solver. The first modification is fully implemented, and comparative performance data are obtained for varying resolution and number of processes, showing a significant storage saving and slightly reduced execution time on a Cray Y -MP 8/864. The important performance parameters for the spectral transform algorithm and its implementation on vector multiprocessors are determined and validated with the measured performance data. The second modification is described at the algorithmic level, but only the novel fast surface spherical truncation algorithm is implemented. This new multipole algorithm has lower complexity than the standard algorithm, and requires asymptotically only order N ^2log N operations per time step for a grid with order N^2 points. Because the global shallow water equations are similar to the horizontal dynamical component of general circulation models, the results can be applied to spectral transform numerical weather prediction and climate models. In general, the derived algorithms may speed up the solution of time dependent partial differential equations in spherical geometry. A performance model
Fast Algorithm for Computing the Discrete Hartley Transform of Type-II
Mounir Taha Hamood
2016-06-01
Full Text Available The generalized discrete Hartley transforms (GDHTs have proved to be an efficient alternative to the generalized discrete Fourier transforms (GDFTs for real-valued data applications. In this paper, the development of direct computation of radix-2 decimation-in-time (DIT algorithm for the fast calculation of the GDHT of type-II (DHT-II is presented. The mathematical analysis and the implementation of the developed algorithm are derived, showing that this algorithm possesses a regular structure and can be implemented in-place for efficient memory utilization.The performance of the proposed algorithm is analyzed and the computational complexity is calculated for different transform lengths. A comparison between this algorithm and existing DHT-II algorithms shows that it can be considered as a good compromise between the structural and computational complexities.
Improved FHT Algorithms for Fast Computation of the Discrete Hartley Transform
M. T. Hamood
2013-05-01
Full Text Available In this paper, by using the symmetrical properties of the discrete Hartley transform (DHT, an improved radix-2 fast Hartley transform (FHT algorithm with arithmetic complexity comparable to that of the real-valued fast Fourier transform (RFFT is developed. It has a simple and regular butterfly structure and possesses the in-place computation property. Furthermore, using the same principles, the development can be extended to more efficient radix-based FHT algorithms. An example for the improved radix-4 FHT algorithm is given to show the validity of the presented method. The arithmetic complexity for the new algorithms are computed and then compared with the existing FHT algorithms. The results of these comparisons have shown that the developed algorithms reduce the number of multiplications and additions considerably.
Generalized total least squares prediction algorithm for universal 3D similarity transformation
Wang, Bin; Li, Jiancheng; Liu, Chao; Yu, Jie
2017-02-01
Three-dimensional (3D) similarity datum transformation is extensively applied to transform coordinates from GNSS-based datum to a local coordinate system. Recently, some total least squares (TLS) algorithms have been successfully developed to solve the universal 3D similarity transformation problem (probably with big rotation angles and an arbitrary scale ratio). However, their procedures of the parameter estimation and new point (non-common point) transformation were implemented separately, and the statistical correlation which often exists between the common and new points in the original coordinate system was not considered. In this contribution, a generalized total least squares prediction (GTLSP) algorithm, which implements the parameter estimation and new point transformation synthetically, is proposed. All of the random errors in the original and target coordinates, and their variance-covariance information will be considered. The 3D transformation model in this case is abstracted as a kind of generalized errors-in-variables (EIV) model and the equation for new point transformation is incorporated into the functional model as well. Then the iterative solution is derived based on the Gauss-Newton approach of nonlinear least squares. The performance of GTLSP algorithm is verified in terms of a simulated experiment, and the results show that GTLSP algorithm can improve the statistical accuracy of the transformed coordinates compared with the existing TLS algorithms for 3D similarity transformation.
Fast 2-D 8×8 discrete cosine transform algorithm for image coding
JI XiuHua; ZHANG CaiMing; WANG JiaYe; BOEY S. H.
2009-01-01
A new fast two-dimension 8×8 discrete cosine transform (2D 8×8 DCT) algorithm based on the charac-teristics of the basic images of 2D DCT is presented. The new algorithm computes each DCT coefficient in turn more independently. Hence, the new algorithm is suitable for 2D DCT pruning algorithm of prun-ing away any number of high-frequency components of 2D DCT. The proposed pruning algorithm ls more efficient than the existing pruning 2D DCT algorithms in terms of the number of arithmetic opera-tions, especially the number of multiplications required in the computation.
Multistep epsilon-algorithm, Shanks' transformation, and Lotka-Volterra system by Hirota's method
Brezinski, Claude; Hu, Xing-Biao; Redivo-Zaglia, Michela; Sun, Jian-Qing
2010-01-01
In this paper, we give a multistep extension of the epsilon-algorithm of Wynn, and we show that it implements a multistep extension of the Shanks' sequence transformation which is defined by ratios of determinants. Reciprocally, the quantities defined in this transformation can be recursively computed by the multistep epsilon-algorithm. The multistep epsilon-algorithm and the multistep Shanks' transformation are related to an extended discrete Lotka-Volterra system. These results are obtained by using the Hirota's bilinear method, a procedure quite useful in the solution of nonlinear partial differential and difference equations.
Lossless Image Compression Using A Simplified MED Algorithm with Integer Wavelet Transform
Mohamed M. Fouad
2013-11-01
Full Text Available In this paper, we propose a lossless (LS image compression technique combining a prediction step with the integer wavelet transform. The prediction step proposed in this technique is a simplified version of the median edge detector algorithm used with JPEG-LS. First, the image is transformed using the prediction step and a difference image is obtained. The difference image goes through an integer wavelet transform and the transform coefficients are used in the lossless codeword assignment. The algorithm is simple and test results show that it yields higher compression ratios than competing techniques. Computational cost is also kept close to competing techniques.
无
2007-01-01
The mismatch between echo and replica caused by underwater moving target(UMT)'s radial velocity degrades the detection performance of the matched filter(MF) for the linear frequency modulation(LFM) signal. By using the focusing property of fractional Fourier transform(FRFT) to that signal, a detection algorithm for UMT's LFM echo based on the discrete fractional Fourier transform(DFRFT) is proposed. This algorithm is less affected by the target's radial velocity compared with the other MF detection algorithm utilizing zero radial velocity replica(ZRVR), and the mathematical relation between the output peak positions of these two algorithms exists in the case of existence of target echo. The algorithm can also estimate the target distance by using this relation. The simulation and experiment show that this algorithm's detection performance is better than or equivalent to that of the other MF algorithm utilizing ZRVR for the LFM echo of UMT with unknown radial velocity under reverberation noise background.
Zhang, Leihong; Liang, Dong; Li, Bei; Kang, Yi; Pan, Zilan; Zhang, Dawei; Gao, Xiumin; Ma, Xiuhua
2016-07-01
On the basis of analyzing the cosine light field with determined analytic expression and the pseudo-inverse method, the object is illuminated by a presetting light field with a determined discrete Fourier transform measurement matrix, and the object image is reconstructed by the pseudo-inverse method. The analytic expression of the algorithm of computational ghost imaging based on discrete Fourier transform measurement matrix is deduced theoretically, and compared with the algorithm of compressive computational ghost imaging based on random measurement matrix. The reconstruction process and the reconstruction error are analyzed. On this basis, the simulation is done to verify the theoretical analysis. When the sampling measurement number is similar to the number of object pixel, the rank of discrete Fourier transform matrix is the same as the one of the random measurement matrix, the PSNR of the reconstruction image of FGI algorithm and PGI algorithm are similar, the reconstruction error of the traditional CGI algorithm is lower than that of reconstruction image based on FGI algorithm and PGI algorithm. As the decreasing of the number of sampling measurement, the PSNR of reconstruction image based on FGI algorithm decreases slowly, and the PSNR of reconstruction image based on PGI algorithm and CGI algorithm decreases sharply. The reconstruction time of FGI algorithm is lower than that of other algorithms and is not affected by the number of sampling measurement. The FGI algorithm can effectively filter out the random white noise through a low-pass filter and realize the reconstruction denoising which has a higher denoising capability than that of the CGI algorithm. The FGI algorithm can improve the reconstruction accuracy and the reconstruction speed of computational ghost imaging.
Labunets, Valeri G.; Labunets-Rundblad, Ekaterina V.; Astola, Jaakko T.
2001-12-01
Fast algorithms for a wide class of non-separable n-dimensional (nD) discrete unitary K-transforms (DKT) are introduced. They need less 1D DKTs than in the case of the classical radix-2 FFT-type approach. The method utilizes a decomposition of the nD K-transform into the product of a new nD discrete Radon transform and of a set of parallel/independ 1D K-transforms. If the nD K-transform has a separable kernel (e.g., the case of the discrete Fourier transform) our approach leads to decrease of multiplicative complexity by the factor of n comparing to the classical row/column separable approach. It is well known that an n-th order Volterra filter of one dimensional signal can be evaluated by an appropriate nD linear convolution. This work describes new superfast algorithm for Volterra filtering. New approach is based on the superfast discrete Radon and Nussbaumer polynomial transforms.
An Efficient Algorithm for the Discrete Gabor Transform using full length Windows
Søndergaard, Peter Lempel
2009-01-01
This paper extends the efficient factorization of the Gabor frame operator developed by Strohmer (1998) to the Gabor analysis/synthesis operator. This provides a fast method for computing the discrete Gabor transform (DGT) and several algorithms associated with it. The algorithm is used for the c...... for the case when the involved window and signal have the same length....
An Efficient Algorithm for the Discrete Gabor Transform using full length Windows
Søndergaard, Peter Lempel
2007-01-01
This paper extends the efficient factorization of the Gabor frame operator developed by Strohmer in [1] to the Gabor analysis/synthesis operator. This provides a fast method for computing the discrete Gabor transform (DGT) and several algorithms associated with it. The algorithm is used for the c...... for the case when the involved window and signal have the same length....
Algorithms for Fast Computing of the 3D-DCT Transform
S. Hanus
2003-04-01
Full Text Available The algorithm for video compression based on the Three-DimensionalDiscrete Cosine Transform (3D-DCT is presented. The original algorithmof the 3D-DCT has high time complexity. We propose several enhancementsto the original algorithm and make the calculation of the DCT algorithmfeasible for future real-time video compression.
An imaging algorithm based on keystone transform for one-stationary bistatic SAR of spotlight mode
Qiu, Xiaolan; Behner, Florian; Reuter, Simon; Nies, Holger; Loffeld, Otmar; Huang, Lijia; Hu, Donghui; Ding, Chibiao
2012-12-01
This article proposes an imaging algorithm based on Keystone Transform for bistatic SAR with a stationary receiver. It can efficiently be applied to high-resolution spotlight mode, and can directly be process the bistatic SAR data which have been ranged compressed by the synchronization reference pulses. Both simulation and experimental results validate the good performance of this algorithm.
Specification of the Fast Fourier Transform algorithm as a term rewriting system
Rodenburg, P.H.; Hoekzema, D.J.
2008-01-01
We specify an algorithm for multiplying polynomials with complex coefficients incorporating, the Fast Fourier Transform algorithm of Cooley and Tukey [CT]. The specification formalism we use is a variant of the formalism ASF described in. [BHK]. The difference with ASF is essentially a matter of sem
A. N. Kuzovlev
2014-01-01
Full Text Available Presents investigations on blocking algorithm for transformer current protections during magnetizing inrush current. The investigations have shown that the algorithm has high sensitivity and reliably determines magnetizing inrush current modes.
Molecular Quantum Computing by an Optimal Control Algorithm for Unitary Transformations
Palao, J P; Palao, Jose P.; Kosloff, Ronnie
2002-01-01
Quantum computation is based on implementing selected unitary transformations which represent algorithms. A generalized optimal control theory is used to find the driving field that generates a prespecified unitary transformation. The approach is illustrated in the implementation of one and two qubits gates in model molecular systems.
Fast alternating projected gradient descent algorithms for recovering spectrally sparse signals
Cho, Myung
2016-06-24
We propose fast algorithms that speed up or improve the performance of recovering spectrally sparse signals from un-derdetermined measurements. Our algorithms are based on a non-convex approach of using alternating projected gradient descent for structured matrix recovery. We apply this approach to two formulations of structured matrix recovery: Hankel and Toeplitz mosaic structured matrix, and Hankel structured matrix. Our methods provide better recovery performance, and faster signal recovery than existing algorithms, including atomic norm minimization.
IMPROVEMENT OF ANOMALY DETECTION ALGORITHMS IN HYPERSPECTRAL IMAGES USING DISCRETE WAVELET TRANSFORM
Kamal Jamshidi; Mohsen Zare Baghbidi; Ahmad Reza Naghsh Nilchi; Saeid Homayouni
2012-01-01
Recently anomaly detection (AD) has become an important application for target detection in hyperspectral remotely sensed images. In many applications, in addition to high accuracy of detection we need a fast and reliable algorithm as well. This paper presents a novel method to improve the performance of current AD algorithms. The proposed method first calculates Discrete Wavelet Transform (DWT) of every pixel vector of image using Daubechies4 wavelet. Then, AD algorithm performs on four band...
Biomedical Image Processing Using FCM Algorithm Based on the Wavelet Transform
YAN Yu-hua; WANG Hui-min; LI Shi-pu
2004-01-01
An effective processing method for biomedical images and the Fuzzy C-mean (FCM) algorithm based on the wavelet transform are investigated.By using hierarchical wavelet decomposition, an original image could be decomposed into one lower image and several detail images. The segmentation started at the lowest resolution with the FCM clustering algorithm and the texture feature extracted from various sub-bands. With the improvement of the FCM algorithm, FCM alternation frequency was decreased and the accuracy of segmentation was advanced.
Super-resolution image restoration algorithms based on orthogonal discrete wavelet transform
Liu, Yang-yang; Jin, Wei-qi
2005-02-01
Several new super-resolution image restoration algorithms based on orthogonal discrete wavelet transform are proposed, by using orthogonal discrete wavelet transform and generalized cross validation ,and combining with Luck-Richardson super-resolution image restoration algorithm (LR) and Luck-Richardson algorithm based on Poisson-Markov model (MPML). Orthogonal discrete wavelet transform analyzed in both space and frequency domain has the capability of indicating local features of a signal, and concentrating the signal power to a few coefficients in wavelet transform domain. After an original image is "Symlets" orthogonal discrete wavelet transformed, an asymptotically optimal threshold is determined by minimizing generalized cross validation, and high frequency subbands in each decomposition level are denoised with soft threshold processes to converge respectively to those with maximum signal-noise-ratio, when the method is incorporated with existed super-resolution image algorithms, details of original image, especially of those with low signal-noise-ratio, could be well recovered. Single operation wavelet LR algorithm(SWLR),single operation wavelet MPML algorithm(SW-MPML) and MPML algorithm based on single operation and wavelet transform (MPML- SW) are some operative algorithms proposed based on the method. According to the processing results to simulating and practical images , because of the only one operation, under the guarantee of rapid and effective restoration processing, in comparison with LR and MPML, all the proposed algorithms could retain image details better, and be more suitable to low signal-noise-ratio images, They could also reduce operation time for up to hundreds times of iteratives, as well as, avoid the iterative operation of self-adaptive parameters in MPML, improve operating speed and precision. They are practical and instantaneous to some extent in the field of low signal-noise-ratio image restoration.
A novel algorithm and architecture of combined direct 2-D transform and quantization for H.264
无
2007-01-01
This paper proposes a novel high-performance direct 2-D transform algorithm which suitably arranges the data processing sequences adopted in row and column transforms of H.264 CODEC systems to finish the data transposition. Simultaneity, this paper proposes a new direct 2-D transform and quantization architectures for H.264 video coding standard. The induced new transform and quantization architecture greatly increases the data processing rate and eliminates transform multiplication and transpose memory, and select different mode and quantization according to AC coefficient, DC coefficient, chrominance block and Luminance block. And this architecture just need to storage one quantization tables for Integer transform and Hadamard transform, but it can do two types of forward transforms and quantization just in one block.
An Improved Singularity Computing Algorithm Based on Wavelet Transform Modulus Maxima Method
ZHAO Jian; XIE Duan; FAN Xun-li
2006-01-01
In order to reduce the hidden danger of noise which can be charactered by singularity spectrum, a new algorithm based on wavelet transform modulus maxima method was proposed. Singularity analysis is one of the most promising new approaches for extracting noise hidden information from noisy time series . Because of singularity strength is hard to calculate accurately, a wavelet transform modulus maxima method was used to get singularity spectrum. The singularity spectrum of white noise and aluminium interconnection electromigration noise was calculated and analyzed. The experimental results show that the new algorithm is more accurate than tradition estimating algorithm. The proposed method is feasible and efficient.
Inverse log polar transformation algorithm based on sub-pixel interpolation
WANG Qi; LI Yan-jun; ZHANG Ke; XIONG Xian-ze
2006-01-01
Log polar transformation is an important algorithm of space-variant vision theory.It well depicts the retino-cortical mapping.Due to the logarithmic and the arctangent operation in the transformation,the log polar coordinate of an image is mostly a decimal fraction and the range is quite narrow.Aiming at solving these problems,this paper puts forward an inverse log polar transformation based on sub-pixel interpolation.The acquired log polar image of the new algorithm has no mosaic phenomenon,meanwhile it is a better simulation of retina-cortical mapping.
Extended-Maxima Transform Watershed Segmentation Algorithm for Touching Corn Kernels
Yibo Qin
2013-01-01
Full Text Available Touching corn kernels are usually oversegmented by the traditional watershed algorithm. This paper proposes a modified watershed segmentation algorithm based on the extended-maxima transform. Firstly, a distance-transformed image is processed by the extended-maxima transform in the range of the optimized threshold value. Secondly, the binary image obtained by the preceding process is run through the watershed segmentation algorithm, and watershed ridge lines are superimposed on the original image, so that touching corn kernels are separated into segments. Fifty images which all contain 400 corn kernels were tested. Experimental results showed that the effect of segmentation is satisfactory by the improved algorithm, and the accuracy of segmentation is as high as 99.87%.
An Image Filter Based on Shearlet Transformation and Particle Swarm Optimization Algorithm
Kai Hu
2015-01-01
Full Text Available Digital image is always polluted by noise and made data postprocessing difficult. To remove noise and preserve detail of image as much as possible, this paper proposed image filter algorithm which combined the merits of Shearlet transformation and particle swarm optimization (PSO algorithm. Firstly, we use classical Shearlet transform to decompose noised image into many subwavelets under multiscale and multiorientation. Secondly, we gave weighted factor to those subwavelets obtained. Then, using classical Shearlet inverse transform, we obtained a composite image which is composed of those weighted subwavelets. After that, we designed fast and rough evaluation method to evaluate noise level of the new image; by using this method as fitness, we adopted PSO to find the optimal weighted factor we added; after lots of iterations, by the optimal factors and Shearlet inverse transform, we got the best denoised image. Experimental results have shown that proposed algorithm eliminates noise effectively and yields good peak signal noise ratio (PSNR.
A sensor node lossless compression algorithm for non-slowly varying data based on DMD transform
Ren, Xuejun; Liu, Jianping
2013-03-01
Efficient utilization of energy is a core area of research in wireless sensor networks. Data compression methods to reduce the number of bits to be transmitted by the communication module will significantly reduce the energy requirement and increase the lifetime of the sensor node. Based on the lifting scheme 2-point discrete cosine transform (DCT), this paper proposed a new reversible recursive algorithm named Difference-Median-Difference (DMD) transform for lossless data compression in sensor node. The DMD transform can significantly reduce the spatio-temporal correlations among sensor data and can smoothly run in resource limited sensor nodes. Through an entropy encoder, the results of DMD transform can be compressed more compactly based on their statistical characteristics to achieve compression. Compared with the typical lossless algorithms, the proposed algorithm indicated better compression ratios than others for non-slowly-varying data, despite a less computational effort.
bahram noshad
2012-11-01
Full Text Available One of mal-operations of the transformer differential protection during the unload transformer energizing with additional line/load from the supplying side is ultra-saturation phenomenon. In this paper, first a new model according to Discrete Fourier Transform (DFT algorithm for investigating the ultra-saturation phenomenon during the unload transformer energizing with additional line/load from the supplying side is presented and its effect on the differential protection of the transformer is considered. In this model, the nonlinear characteristic of the transformer core and the effect of current transformer are taken into account. It is assumed that the additional line/load from the supplying side of the power transformer is a resistive-inductive load. Also, the effect of the residual flux, inception angle and additional line/load from the supplying side on the ultra-saturation phenomenon is investigated. Then, the mal-operation of differential protection by using DFT algorithm is described.
Amirfattahi, Rassoul
2013-10-01
Owing to its simplicity radix-2 is a popular algorithm to implement fast fourier transform. Radix-2(p) algorithms have the same order of computational complexity as higher radices algorithms, but still retain the simplicity of radix-2. By defining a new concept, twiddle factor template, in this paper, we propose a method for exact calculation of multiplicative complexity for radix-2(p) algorithms. The methodology is described for radix-2, radix-2 (2) and radix-2 (3) algorithms. Results show that radix-2 (2) and radix-2 (3) have significantly less computational complexity compared with radix-2. Another interesting result is that while the number of complex multiplications in radix-2 (3) algorithm is slightly more than radix-2 (2), the number of real multiplications for radix-2 (3) is less than radix-2 (2). This is because of the twiddle factors in the form of which need less number of real multiplications and are more frequent in radix-2 (3) algorithm.
An upper bound to the second Hankel determinant for pre-starlike functions of order α
Deekonda Vamshee Krishna
2015-12-01
Full Text Available The objective of this paper is to obtain an upper bound to the second Hankel determinant for the function f and its inverse belonging to the class of pre-starlike functions of order alpha (0 ≤ alpha ≤ 1, using Toeplitz determinants.
Model reduction for nonlinear systems based on the differential eigenstructure of Hankel operators
Fujimoto, Kenji; Scherpen, Jacquelien M.A.
2001-01-01
This paper offers a new input-normal output-diagonal realization and model reduction procedure for nonlinear systems based on the differential eigenstructure of Hankel operators. Firstly, we refer to the preliminary results on input-normal realizations with original singular value functions and the
Distributed edge detection algorithm based on wavelet transform for wireless video sensor network
Li, Qiulin; Hao, Qun; Song, Yong; Wang, Dongsheng
2011-05-01
Edge detection algorithms are critical to image processing and computer vision. Traditional edge detection algorithms are not suitable for wireless video sensor network (WVSN) in which the nodes are with in limited calculation capability and resources. In this paper, a distributed edge detection algorithm based on wavelet transform designed for WVSN is proposed. Wavelet transform decompose the image into several parts, then the parts are assigned to different nodes through wireless network separately. Each node performs sub-image edge detecting algorithm correspondingly, all the results are sent to sink node, Fusing and Synthesis which include image binary and edge connect are executed in it. And finally output the edge image. Lifting scheme and parallel distributed algorithm are adopted to improve the efficiency, simultaneously, decrease the computational complexity. Experimental results show that this method could achieve higher efficiency and better result.
Improvement of Anomoly Detection Algorithms in Hyperspectral Images using Discrete Wavelet Transform
Baghbidi, Mohsen Zare; Nilchi, Ahmad Reza Naghsh; Homayouni, Saeid; 10.5121/sipij.2011.2402
2012-01-01
Recently anomaly detection (AD) has become an important application for target detection in hyperspectral remotely sensed images. In many applications, in addition to high accuracy of detection we need a fast and reliable algorithm as well. This paper presents a novel method to improve the performance of current AD algorithms. The proposed method first calculates Discrete Wavelet Transform (DWT) of every pixel vector of image using Daubechies4 wavelet. Then, AD algorithm performs on four bands of "Wavelet transform" matrix which are the approximation of main image. In this research some benchmark AD algorithms including Local RX, DWRX and DWEST have been implemented on Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) hyperspectral datasets. Experimental results demonstrate significant improvement of runtime in proposed method. In addition, this method improves the accuracy of AD algorithms because of DWT's power in extracting approximation coefficients of signal, which contain the main behaviour of sig...
Nuclide identification algorithm based on K-L transform and neural networks
Chen Liang [Key Laboratory of Particle and Radiation Imaging (Tsinghua University), Department of Engineering Physics, Tsinghua University, Ministry of Education (China)], E-mail: cliang00@mails.tsinghua.edu.cn; Wei Yixiang [Key Laboratory of Particle and Radiation Imaging (Tsinghua University), Department of Engineering Physics, Tsinghua University, Ministry of Education (China)
2009-01-11
Traditional spectrum analysis algorithm based on peak search is hard to deal with complex overlapped peaks, especially in bad resolution and high background conditions. This paper described a new nuclide identification method based on the Karhunen-Loeve transform (K-L transform) and artificial neural networks. By the K-L transform and feature extraction, the nuclide gamma spectrum was compacted. The K-L transform coefficients were used as the neural network's input. The linear associative memory and ADALINE were discussed. Lots of experiments and tests showed that the method was credible and practical, especially suitable for fast nuclide identification.
Nuclide identification algorithm based on K-L transform and neural networks
Chen, Liang; Wei, Yi-Xiang
2009-01-01
Traditional spectrum analysis algorithm based on peak search is hard to deal with complex overlapped peaks, especially in bad resolution and high background conditions. This paper described a new nuclide identification method based on the Karhunen-Loeve transform (K-L transform) and artificial neural networks. By the K-L transform and feature extraction, the nuclide gamma spectrum was compacted. The K-L transform coefficients were used as the neural network's input. The linear associative memory and ADALINE were discussed. Lots of experiments and tests showed that the method was credible and practical, especially suitable for fast nuclide identification.
Civicioglu, Pinar
2012-09-01
In order to solve numerous practical navigational, geodetic and astro-geodetic problems, it is necessary to transform geocentric cartesian coordinates into geodetic coordinates or vice versa. It is very easy to solve the problem of transforming geodetic coordinates into geocentric cartesian coordinates. On the other hand, it is rather difficult to solve the problem of transforming geocentric cartesian coordinates into geodetic coordinates as it is very hard to define a mathematical relationship between the geodetic latitude (φ) and the geocentric cartesian coordinates (X, Y, Z). In this paper, a new algorithm, the Differential Search Algorithm (DS), is presented to solve the problem of transforming the geocentric cartesian coordinates into geodetic coordinates and its performance is compared with the performances of the classical methods (i.e., Borkowski, 1989; Bowring, 1976; Fukushima, 2006; Heikkinen, 1982; Jones, 2002; Zhang, 2005; Borkowski, 1987; Shu, 2010 and Lin, 1995) and Computational-Intelligence algorithms (i.e., ABC, JDE, JADE, SADE, EPSDE, GSA, PSO2011, and CMA-ES). The statistical tests realized for the comparison of performances indicate that the problem-solving success of DS algorithm in transforming the geocentric cartesian coordinates into geodetic coordinates is higher than those of all classical methods and Computational-Intelligence algorithms used in this paper.
Vladimir A. Batura
2014-11-01
Full Text Available The efficiency of orthogonal transformations application in the frequency algorithms of the digital watermarking of still images is examined. Discrete Hadamard transform, discrete cosine transform and discrete Haar transform are selected. Their effectiveness is determined by the invisibility of embedded in digital image watermark and its resistance to the most common image processing operations: JPEG-compression, noising, changing of the brightness and image size, histogram equalization. The algorithm for digital watermarking and its embedding parameters remain unchanged at these orthogonal transformations. Imperceptibility of embedding is defined by the peak signal to noise ratio, watermark stability– by Pearson's correlation coefficient. Embedding is considered to be invisible, if the value of the peak signal to noise ratio is not less than 43 dB. Embedded watermark is considered to be resistant to a specific attack, if the Pearson’s correlation coefficient is not less than 0.5. Elham algorithm based on the image entropy is chosen for computing experiment. Computing experiment is carried out according to the following algorithm: embedding of a digital watermark in low-frequency area of the image (container by Elham algorithm, exposure to a harmful influence on the protected image (cover image, extraction of a digital watermark. These actions are followed by quality assessment of cover image and watermark on the basis of which efficiency of orthogonal transformation is defined. As a result of computing experiment it was determined that the choice of the specified orthogonal transformations at identical algorithm and parameters of embedding doesn't influence the degree of imperceptibility for a watermark. Efficiency of discrete Hadamard transform and discrete cosine transformation in relation to the attacks chosen for experiment was established based on the correlation indicators. Application of discrete Hadamard transform increases
A study of Hough Transform-based fingerprint alignment algorithms
Mlambo, CS
2014-10-01
Full Text Available array. In 2013 Paulino et al [10] applied Ratha et al’s [2] approach in latent fingerprint matching to present a descriptor-based Hough transform. This involved the use of orientation field and minutiae information to accumulate evidence into accumulator... and improves on the early work presented in the 1990’s, as presented in [5], [14], [8], [17], [11], [10], and [12]. As a result, the memory requirements, computing time and performance on different conditions of minutiae points has not been presented...
Piovesan, Luis Sergio
1997-07-01
The appliance of two algorithms is evaluated, one based in Fourier analysis and other based in a rectangular transform technique over Fourier analysis, to be used in digital logical circuits (digital protection relays) for the purpose of differential protection of power transformers (ANSI 87T). The first chapter has a brief introduction about electrical protection. The second chapter discusses the general problems of transform protection, the development of digital technology and, with more detail, the differential protection associated to this technology. In this chapter are presented the particular aspects of transformers differential protection concerning sensibility, inrush current situations and harmonic distortions caused by transformer core saturations and the differential protection algorithms and their applications in a specific relay design. In chapter three, a method to make possible testing the protection performance is developed. This work applies digital simulations using EMTP to generate current signal of transformer operation and fault conditions. Digital simulation using Matlab is used to simulate the protection. The EMTP generated field signals are sent to the relay under test, furnishing data of normal operation, internal and external faults. The relay logic simulator at Matlab will work this data and so, it will be possible to verify and evaluate the algorithm behavior and performance. Chapter 4 shows the protection operation over simulations of several of transformer operation and fault conditions. The last chapter presents a conclusion about the protection performance, discussions about all the methods applied in this work and suggestions for further studies. (author)
Sandryhaila, Aliaksei; Pueschel, Markus
2010-01-01
A polynomial transform is the multiplication of an input vector $x\\in\\C^n$ by a matrix $\\PT_{b,\\alpha}\\in\\C^{n\\times n},$ whose $(k,\\ell)$-th element is defined as $p_\\ell(\\alpha_k)$ for polynomials $p_\\ell(x)\\in\\C[x]$ from a list $b=\\{p_0(x),\\dots,p_{n-1}(x)\\}$ and sample points $\\alpha_k\\in\\C$ from a list $\\alpha=\\{\\alpha_0,\\dots,\\alpha_{n-1}\\}$. Such transforms find applications in the areas of signal processing, data compression, and function interpolation. Important examples include the discrete Fourier and cosine transforms. In this paper we introduce a novel technique to derive fast algorithms for polynomial transforms. The technique uses the relationship between polynomial transforms and the representation theory of polynomial algebras. Specifically, we derive algorithms by decomposing the regular modules of these algebras as a stepwise induction. As an application, we derive novel $O(n\\log{n})$ general-radix algorithms for the discrete Fourier transform and the discrete cosine transform of type 4.
Quasi-conformal mapping with genetic algorithms applied to coordinate transformations
González-Matesanz, F. J.; Malpica, J. A.
2006-11-01
In this paper, piecewise conformal mapping for the transformation of geodetic coordinates is studied. An algorithm, which is an improved version of a previous algorithm published by Lippus [2004a. On some properties of piecewise conformal mappings. Eesti NSV Teaduste Akademmia Toimetised Füüsika-Matemaakika 53, 92-98; 2004b. Transformation of coordinates using piecewise conformal mapping. Journal of Geodesy 78 (1-2), 40] is presented; the improvement comes from using a genetic algorithm to partition the complex plane into convex polygons, whereas the original one did so manually. As a case study, the method is applied to the transformation of the Spanish datum ED50 and ETRS89, and both its advantages and disadvantages are discussed herein.
Multi-image gradient-based algorithms for motion measurement using wavelet transform
2008-01-01
A multi-image wavelet transform motion estimation algorithm based on gradient methods is presented by using the characteristic of wavelet transfom.In this algorithm,the accuracy can be improved greatly using data in many images to measure motions between two images.In combination with the reliability measure for constraints function,the reliable data constraints of the images were decomposed with multi-level simultaneous wavelet transform rather than the traditional coarse-to-fine approach.Compared with conventional methods,this motion measurement algorithm based on multi-level simultaneous wavelet transform avoids propagating errors between the decomposed levels.Experimental simulations show that the implementation of this algo rithm is simple,and the measurement accuracy is improved.
Super-resolution image restoration algorithm based on orthogonal discrete wavelet transform
Yangyang Liu(刘扬阳); Weiqi Jin(金伟其); Binghua Su(苏秉华)
2004-01-01
By using orthogonal discrete wavelet transform(ODWT)and generalized cross validation(GCV),and combining with Luck-Richardson algorithm based on Poisson-Markovmodel (MPML),several new superresolution image restoration algorithms are proposed.According to simulation experiments for practical images,all the proposed algor ithms could retain image details better than MPML,and be more suitable to low signal-to-noise ratio(SNR)images.The single operation wavelet MPML(SW-MPML)algorithm and MPML algorithm based on single operation wavelet transform(MPML-SW)avoid the iterative operation of self-adaptive parameter in MPML particularly,and improve operating speed and precision.They are instantaneous to super-resolution image restoration process and have extensive application foreground.
Changjiang Zhang; Xiaodong Wang; Haoran Zhang
2005-01-01
A new contrast enhancement algorithm for image is proposed employing wavelet neural network (WNN)and stationary wavelet transform (SWT). Incomplete Beta transform (IBT) is used to enhance the global contrast for image. In order to avoid the expensive time for traditional contrast enhancement algorithms,which search optimal gray transform parameters in the whole gray transform parameter space, a new criterion is proposed with gray level histogram. Contrast type for original image is determined employing the new criterion. Gray transform parameter space is given respectively according to different contrast types,which shrinks the parameter space greatly. Nonlinear transform parameters are searched by simulated annealing algorithm (SA) so as to obtain optimal gray transform parameters. Thus the searching direction and selection of initial values of simulated annealing is guided by the new parameter space. In order to calculate IBT in the whole image, a kind of WNN is proposed to approximate the IBT. Having enhanced the global contrast to input image, discrete SWT is done to the image which has been processed by previous global enhancement method, local contrast enhancement is implemented by a kind of nonlinear operator in the high frequency sub-band images of each decomposition level respectively. Experimental results show that the new algorithm is able to adaptively enhance the global contrast for the original image while it also extrudes the detail of the targets in the original image well. The computation complexity for the new algorithm is O(MN) log(MN), where M and N are width and height of the original image, respectively.
M. I. Fursanov
2014-01-01
Full Text Available This article reflects algorithmization of search methods of effective replacement of consumer transformers in distributed electrical networks. As any electrical equipment of power systems, power transformers have their own limited service duration, which is determined by natural processes of materials degradation and also by unexpected wear under different conditions of overload and overvoltage. According to the standards, adapted by in the Republic of Belarus, rated service life of power transformers is 25 years. But it can be situations that transformers should be better changed till this time – economically efficient. The possibility of such replacement is considered in order to increase efficiency of electrical network operation connected with its physical wear and aging.In this article the faults of early developed mathematical models of transformers replacement were discussed. Early such worked out transformers were not used. But in practice they can be replaced in one substation but they can be successfully used in other substations .Especially if there are limits of financial resources and the replacement needs more detail technical and economical basis.During the research the authors developed the efficient algorithm for determining of optimal location of transformers at substations of distributed electrical networks, based on search of the best solution from all sets of displacement in oriented graph. Suggested algorithm allows considerably reduce design time of optimal placement of transformers using a set of simplifications. The result of algorithm’s work is series displacement of transformers in networks, which allow obtain a great economic effect in comparison with replacement of single transformer.
Hui Huang
2017-01-01
Full Text Available According to the pros and cons of contourlet transform and multimodality medical imaging, here we propose a novel image fusion algorithm that combines nonlinear approximation of contourlet transform with image regional features. The most important coefficient bands of the contourlet sparse matrix are retained by nonlinear approximation. Low-frequency and high-frequency regional features are also elaborated to fuse medical images. The results strongly suggested that the proposed algorithm could improve the visual effects of medical image fusion and image quality, image denoising, and enhancement.
Point Pattern Matching Algorithm for Planar Point Sets under Euclidean Transform
Xiaoyun Wang
2012-01-01
Full Text Available Point pattern matching is an important topic of computer vision and pattern recognition. In this paper, we propose a point pattern matching algorithm for two planar point sets under Euclidean transform. We view a point set as a complete graph, establish the relation between the point set and the complete graph, and solve the point pattern matching problem by finding congruent complete graphs. Experiments are conducted to show the effectiveness and robustness of the proposed algorithm.
Liu, XiangShao; Zhou, Shangbo; Li, Hua; Li, Kun
2016-01-01
In this article, a bidirectional feature matching algorithm and two extended algorithms based on the priority k-d tree search are presented for the image registration using scale-invariant feature transform features...
Improved Algorithm for Analysis of DNA Sequences Using Multiresolution Transformation
T. M. Inbamalar
2015-01-01
Full Text Available Bioinformatics and genomic signal processing use computational techniques to solve various biological problems. They aim to study the information allied with genetic materials such as the deoxyribonucleic acid (DNA, the ribonucleic acid (RNA, and the proteins. Fast and precise identification of the protein coding regions in DNA sequence is one of the most important tasks in analysis. Existing digital signal processing (DSP methods provide less accurate and computationally complex solution with greater background noise. Hence, improvements in accuracy, computational complexity, and reduction in background noise are essential in identification of the protein coding regions in the DNA sequences. In this paper, a new DSP based method is introduced to detect the protein coding regions in DNA sequences. Here, the DNA sequences are converted into numeric sequences using electron ion interaction potential (EIIP representation. Then discrete wavelet transformation is taken. Absolute value of the energy is found followed by proper threshold. The test is conducted using the data bases available in the National Centre for Biotechnology Information (NCBI site. The comparative analysis is done and it ensures the efficiency of the proposed system.
Improved algorithm for analysis of DNA sequences using multiresolution transformation.
Inbamalar, T M; Sivakumar, R
2015-01-01
Bioinformatics and genomic signal processing use computational techniques to solve various biological problems. They aim to study the information allied with genetic materials such as the deoxyribonucleic acid (DNA), the ribonucleic acid (RNA), and the proteins. Fast and precise identification of the protein coding regions in DNA sequence is one of the most important tasks in analysis. Existing digital signal processing (DSP) methods provide less accurate and computationally complex solution with greater background noise. Hence, improvements in accuracy, computational complexity, and reduction in background noise are essential in identification of the protein coding regions in the DNA sequences. In this paper, a new DSP based method is introduced to detect the protein coding regions in DNA sequences. Here, the DNA sequences are converted into numeric sequences using electron ion interaction potential (EIIP) representation. Then discrete wavelet transformation is taken. Absolute value of the energy is found followed by proper threshold. The test is conducted using the data bases available in the National Centre for Biotechnology Information (NCBI) site. The comparative analysis is done and it ensures the efficiency of the proposed system.
A contourlet transform based algorithm for real-time video encoding
Katsigiannis, Stamos; Papaioannou, Georgios; Maroulis, Dimitris
2012-06-01
In recent years, real-time video communication over the internet has been widely utilized for applications like video conferencing. Streaming live video over heterogeneous IP networks, including wireless networks, requires video coding algorithms that can support various levels of quality in order to adapt to the network end-to-end bandwidth and transmitter/receiver resources. In this work, a scalable video coding and compression algorithm based on the Contourlet Transform is proposed. The algorithm allows for multiple levels of detail, without re-encoding the video frames, by just dropping the encoded information referring to higher resolution than needed. Compression is achieved by means of lossy and lossless methods, as well as variable bit rate encoding schemes. Furthermore, due to the transformation utilized, it does not suffer from blocking artifacts that occur with many widely adopted compression algorithms. Another highly advantageous characteristic of the algorithm is the suppression of noise induced by low-quality sensors usually encountered in web-cameras, due to the manipulation of the transform coefficients at the compression stage. The proposed algorithm is designed to introduce minimal coding delay, thus achieving real-time performance. Performance is enhanced by utilizing the vast computational capabilities of modern GPUs, providing satisfactory encoding and decoding times at relatively low cost. These characteristics make this method suitable for applications like video-conferencing that demand real-time performance, along with the highest visual quality possible for each user. Through the presented performance and quality evaluation of the algorithm, experimental results show that the proposed algorithm achieves better or comparable visual quality relative to other compression and encoding methods tested, while maintaining a satisfactory compression ratio. Especially at low bitrates, it provides more human-eye friendly images compared to
Radix-3 Algorithm for Realization of Type-II Discrete Sine Transform
M. N. Murty
2015-06-01
Full Text Available In this paper, radix-3 algorithm for computation of type-II discrete sine transform (DST-II of length N = 3 ( = 1,2, … . is presented. The DST-II of length N can be realized from three DST-II sequences, each of length N/3. A block diagram of for computation of the radix-3 DST-II algorithm is given. Signal flow graph for DST-II of length = 3 2 is shown to clarify the proposed algorithm.
Improvements on the minimax algorithm for the Laplace transformation of orbital energy denominators
Helmich-Paris, Benjamin, E-mail: b.helmichparis@vu.nl; Visscher, Lucas, E-mail: l.visscher@vu.nl
2016-09-15
We present a robust and non-heuristic algorithm that finds all extremum points of the error distribution function of numerically Laplace-transformed orbital energy denominators. The extremum point search is one of the two key steps for finding the minimax approximation. If pre-tabulation of initial guesses is supposed to be avoided, strategies for a sufficiently robust algorithm have not been discussed so far. We compare our non-heuristic approach with a bracketing and bisection algorithm and demonstrate that 3 times less function evaluations are required altogether when applying it to typical non-relativistic and relativistic quantum chemical systems.
Zielinski, B.; Patorski, K.
2008-12-01
The aim of this paper is to analyze the accuracy of 2D fringe pattern denoising performed by two chosen methods using quasi-1D two-arm spin filter and 2D Discrete Wavelet Transform (DWT) signal decomposition and thresholding. The ultimate aim of this comparison is to estimate which algorithm is better suited for high-accuracy interferometric measurements. In spite of the fact that both algorithms are designed to minimize possible fringe blur and distortion, the evaluation of errors introduced by each algorithm is essential for proper estimation of their performance.
Discrete cosine and sine transforms general properties, fast algorithms and integer approximations
Britanak, Vladimir; Rao, K R; Rao, K R
2006-01-01
The Discrete Cosine Transform (DCT) is used in many applications by the scientific, engineering and research communities and in data compression in particular. Fast algorithms and applications of the DCT Type II (DCT-II) have become the heart of many established international image/video coding standards. Since then other forms of the DCT and Discrete Sine Transform (DST) have been investigated in detail. This new edition presents the complete set of DCT and DST discrete trigonometric transforms, including their definitions, general mathematical properties, and relations to the optimal Karhune
A COMPRESSION ALGORITHM FOR ECG BASED ON INTEGER LIFTING SCHEME WAVELET TRANSFORM
无
2007-01-01
In view of the shortcomes of conventional ElectroCardioGram (ECG) compression algorithms, such as high complexity of operation and distortion of reconstructed signal, a new ECG compression encoding algorithm based on Set Partitioning In Hierarchical Trees (SPIHT) is brought out after studying the integer lifting scheme wavelet transform in detail. The proposed algorithm modifies zero-tree structure of SPIHT, establishes single dimensional wavelet coefficient tree of ECG signals and enhances the efficiency of SPIHT-encoding by distributing bits rationally, improving zero-tree set and ameliorating classifying method. For this improved algorithm, floating-point computation and storage are left out of consideration and it is easy to be implemented by hardware and software. Experimental results prove that the new algorithm has admirable features of low complexity,high speed and good performance in signal reconstruction. High compression ratio is obtained with high signal fidelity as well.
YIN Hong; CHEN Zeng-qiang; YUAN Zhu-zhi
2006-01-01
@@ A hyperchaos-based watermarking algorithm is developed in the wavelet domain for images.The algorithm is based on discrete wavelet transform and combines the communication model with side information.We utilize a suitable scale factor to scale host image,then construct cosets for embedding digital watermarking according to scale version of the host image.Our scheme makes a tradeoff between imperceptibility and robustness,and achieves security.The extraction algorithm is a blind detection algorithm which retrieves the watermark without the original host image.In addition,we propose a new method for watermark encryption with hyperchaotic sequence.This method overcomes the drawback of small key space of chaotic sequence and improves the watermark security.Simulation results indicate that the algorithm is a well-balanced watermarking method that offers good robustness and imperceptibility.
Fast heap transform-based QR-decomposition of real and complex matrices: algorithms and codes
Grigoryan, Artyom M.
2015-03-01
In this paper, we describe a new look on the application of Givens rotations to the QR-decomposition problem, which is similar to the method of Householder transformations. We apply the concept of the discrete heap transform, or signal-induced unitary transforms which had been introduced by Grigoryan (2006) and used in signal and image processing. Both cases of real and complex nonsingular matrices are considered and examples of performing QR-decomposition of square matrices are given. The proposed method of QR-decomposition for the complex matrix is novel and differs from the known method of complex Givens rotation and is based on analytical equations for the heap transforms. Many examples illustrated the proposed heap transform method of QR-decomposition are given, algorithms are described in detail, and MATLAB-based codes are included.
Estimating Rigid Transformation Between Two Range Maps Using Expectation Maximization Algorithm
Zeng, Shuqing
2012-01-01
We address the problem of estimating a rigid transformation between two point sets, which is a key module for target tracking system using Light Detection And Ranging (LiDAR). A fast implementation of Expectation-maximization (EM) algorithm is presented whose complexity is O(N) with $N$ the number of scan points.
Reiteration of Hankel singular value decomposition for modeling of complex-valued signal
Staniszewski, Michał; Skorupa, Agnieszka; Boguszewicz, Łukasz; Wicher, Magdalena; Konopka, Marek; Sokół, Maria; Polański, Andrzej
2016-06-01
Modeling signal which forms complex values is a common scientific problem, which is present in many applications, i.e. in medical signals, computer graphics and vision. One of the possible solution is utilization of Hankel Singular Value Decomposition. In the first step complex-valued signal is arranged in a special form called Hankel matrix, which is in the next step decomposed in operation of Singular Value Decomposition. Obtained matrices can be then reformulated in order to get parameters describing system. Basic method can be applied for fitting whole signal but it fails in modeling each particular component of signal. Modification of basic HSVD method, which relies on reiteration and is used for main components, and application of prior knowledge solves presented problem.
Analysis of the Chirplet Transform-Based Algorithm for Radar Detection of Accelerated Targets
Galushko, V. G.; Vavriv, D. M.
2017-06-01
Purpose: Efficiency analysis of an optimal algorithm of chirp signal processing based on the chirplet transform as applied to detection of radar targets in uniformly accelerated motion. Design/methodology/approach: Standard methods of the optimal filtration theory are used to investigate the ambiguity function of chirp signals. Findings: An analytical expression has been derived for the ambiguity function of chirp signals that is analyzed with respect to detection of radar targets moving at a constant acceleration. Sidelobe level and characteristic width of the ambiguity function with respect to the coordinates frequency and rate of its change have been estimated. The gain in the signal-to-noise ratio has been assessed that is provided by the algorithm under consideration as compared with application of the standard Fourier transform to detection of chirp signals against a “white” noise background. It is shown that already with a comparatively small (block diagram of implementation of the algorithm under consideration is suggested on the basis of a multichannel weighted Fourier transform. Recommendations as for selection of the detection algorithm parameters have been developed. Conclusions: The obtained results testify to efficiency of application of the algorithm under consideration to detection of radar targets moving at a constant acceleration. Nevertheless, it seems expedient to perform computer simulations of its operability with account for the noise impact along with trial measurements in real conditions.
Luo Wei
2017-01-01
Full Text Available Power transformer is one of the most important equipment in power system. In order to predict the potential fault of power transformer and identify the fault types correctly, we proposed a transformer fault intelligent diagnosis model based on chemical reaction optimization (CRO algorithm and relevance vector machine(RVM. RVM is a powerful machine learning method, which can solve nonlinear, high-dimensional classification problems with a limited number of samples. CRO algorithm has well global optimization and simple calculation, so it is suitable to solve parameter optimization problems. In this paper, firstly, a multi-layer RVM classification model was built by binary tree recognition strategy. Secondly, CRO algorithm was adopted to optimize the kernel function parameters which could enhance the performance of RVM classifiers. Compared with IEC three-ratio method and the RVM model, the CRO-RVM model not only overcomes the coding defect problem of IEC three-ratio method, but also has higher classification accuracy than the RVM model. Finally, the new method was applied to analyze a transformer fault case, Its predicted result accord well with the real situation. The research provides a practical method for transformer fault intelligent diagnosis and prediction.
Application of reiteration of Hankel singular value decomposition in quality control
Staniszewski, Michał; Skorupa, Agnieszka; Boguszewicz, Łukasz; Michalczuk, Agnieszka; Wereszczyński, Kamil; Wicher, Magdalena; Konopka, Marek; Sokół, Maria; Polański, Andrzej
2017-07-01
Medical centres are obliged to store past medical records, including the results of quality assurance (QA) tests of the medical equipment, which is especially useful in checking reproducibility of medical devices and procedures. Analysis of multivariate time series is an important part of quality control of NMR data. In this work we proposean anomaly detection tool based on Reiteration of Hankel Singular Value Decomposition method. The presented method was compared with external software and authors obtained comparable results.
Toeplitz and Hankel Products on Bergman Spaces of the Unit Ball
Yufeng LU; Chaomei LIU
2009-01-01
The authors give some new necessary conditions for the boundedness of Toeplitzproducts TafTagon the weighted Bergman space A2a of the unit ball, where f and g are analytic on the unit ball. Hankel products HfH*g on the weighted Bergman space of the unit ball are studied, and the results analogous to those Stroethoff and Zheng obtained in the setting of unit disk are proved.
An Image Filter Based on Multiobjective Genetic Algorithm and Shearlet Transformation
Zhi-yong Fan
2013-01-01
Full Text Available Rician noise pollutes magnetic resonance imaging (MRI data, making data’s postprocessing difficult. In order to remove this noise and avoid loss of details as much as possible, we proposed a filter algorithm using both multiobjective genetic algorithm (MOGA and Shearlet transformation. Firstly, the multiscale wavelet decomposition is applied to the target image. Secondly, the MOGA target function is constructed by evaluation methods, such as signal-to-noise ratio (SNR and mean square error (MSE. Thirdly, MOGA is used with optimal coefficients of Shearlet wavelet threshold value in a different scale and a different orientation. Finally, the noise-free image could be obtained through inverse wavelet transform. At the end of the paper, experimental results show that this proposed algorithm eliminates Rician noise more effectively and yields better peak signal-to-noise ratio (PSNR gains compared with other traditional filters.
Chen, Yang
2010-01-01
In this paper we compute two important information-theoretic quantities which arise in the application of multiple-input multiple-output (MIMO) antenna wireless communication systems: the distribution of the mutual information of multi-antenna Gaussian channels, and the Gallager random coding upper bound on the error probability achievable by finite-length channel codes. It turns out that the mathematical problem underpinning both quantities is the computation of certain Hankel determinants generated by deformed versions of classical weight functions. For single-user MIMO systems, it is a deformed Laguerre weight, whereas for multi-user MIMO systems it is a deformed Jacobi weight. We apply two different methods to characterize each of these Hankel determinants. First, we employ the ladder operators of the corresponding monic orthogonal polynomials to give an exact characterization of the Hankel determinants in terms of Painlev\\'{e} differential equations. This turns out to be a Painlev\\'{e} V for the single-u...
HU; Xingtang; ZHANG; Bing; ZHANG; Xia; ZHENG; Lanfen; TONG; Qingxi
2006-01-01
Starting with a fractal-based image-compression algorithm based on wavelet transformation for hyperspectral images, the authors were able to obtain more spectral bands with the help of of hyperspectral remote sensing. Because large amounts of data and limited bandwidth complicate the storage and transmission of data measured by TB-level bits, it is important to compress image data acquired by hyperspectral sensors such as MODIS, PHI, and OMIS; otherwise, conventional lossless compression algorithms cannot reach adequate compression ratios. Other loss-compression methods can reach high compression ratios but lack good image fidelity, especially for hyperspectral image data. Among the third generation of image compression algorithms, fractal image compression based on wavelet transformation is superior to traditional compression methods,because it has high compression ratios and good image fidelity, and requires less computing time. To keep the spectral dimension invariable, the authors compared the results of two compression algorithms based on the storage-file structures of BSQ and of BIP, and improved the HV and Quadtree partitioning and domain-range matching algorithms in order to accelerate their encode/decode efficiency. The authors' Hyperspectral Image Process and Analysis System (HIPAS) software used a VC++6.0 integrated development environment (IDE), with which good experimental results were obtained. Possible modifications of the algorithm and limitations of the method are also discussed.
New image compression algorithm based on improved reversible biorthogonal integer wavelet transform
Zhang, Libao; Yu, Xianchuan
2012-10-01
The low computational complexity and high coding efficiency are the most significant requirements for image compression and transmission. Reversible biorthogonal integer wavelet transform (RB-IWT) supports the low computational complexity by lifting scheme (LS) and allows both lossy and lossless decoding using a single bitstream. However, RB-IWT degrades the performances and peak signal noise ratio (PSNR) of the image coding for image compression. In this paper, a new IWT-based compression scheme based on optimal RB-IWT and improved SPECK is presented. In this new algorithm, the scaling parameter of each subband is chosen for optimizing the transform coefficient. During coding, all image coefficients are encoding using simple, efficient quadtree partitioning method. This scheme is similar to the SPECK, but the new method uses a single quadtree partitioning instead of set partitioning and octave band partitioning of original SPECK, which reduces the coding complexity. Experiment results show that the new algorithm not only obtains low computational complexity, but also provides the peak signal-noise ratio (PSNR) performance of lossy coding to be comparable to the SPIHT algorithm using RB-IWT filters, and better than the SPECK algorithm. Additionally, the new algorithm supports both efficiently lossy and lossless compression using a single bitstream. This presented algorithm is valuable for future remote sensing image compression.
3D printing optical watermark algorithms based on the combination of DWT and Fresnel transformation
Hu, Qi; Duan, Jin; Zhai, Di; Wang, LiNing
2016-10-01
With the continuous development of industrialization, 3D printing technology steps into individuals' lives gradually, however, the consequential security issue has become the urgent problem which is imminent. This paper proposes the 3D printing optical watermark algorithms based on the combination of DWT and Fresnel transformation and utilizes authorized key to restrict 3D model printing's permissions. Firstly, algorithms put 3D model into affine transform, and take the distance from the center of gravity to the vertex of 3D object in order to generate a one-dimensional discrete signal; then make this signal into wavelet transform and put the transformed coefficient into Fresnel transformation. Use math model to embed watermark information into it and finally generate 3D digital model with watermarking. This paper adopts VC++.NET and DIRECTX 9.0 SDK for combined developing and testing, and the results show that in fixed affine space, achieve the robustness in translation, revolving and proportion transforms of 3D model and better watermark-invisibility. The security and authorization of 3D model have been protected effectively.
Transform analysis of generalized functions
Misra, O P
1986-01-01
Transform Analysis of Generalized Functions concentrates on finite parts of integrals, generalized functions and distributions. It gives a unified treatment of the distributional setting with transform analysis, i.e. Fourier, Laplace, Stieltjes, Mellin, Hankel and Bessel Series.Included are accounts of applications of the theory of integral transforms in a distributional setting to the solution of problems arising in mathematical physics. Information on distributional solutions of differential, partial differential equations and integral equations is conveniently collected here.The volume will
Shuang-qing WU; Yin ZHANG; San-yuan ZHANG; Xiu-zi YE
2009-01-01
An integrated and reliable phase unwrapping algorithm is proposed based on residues and blocking-lines detection,closed contour extraction and quality map ordering for the measurement of 3D shapes by Fourier-transform profilometry (FTP).The proposed algorithm first detects the residues on the wrapped phase image, applies wavelet analysis to generate the blockinglines that can just connect the residues of opposite polarity, then carries out the morphology operation to extract the closed contour of the shape, and finally uses the modulation intensity information and the Laplacian of Gaussian operation of the wrapped phase image as the quality map. The unwrapping process is completed from a region of high reliability to that of low reliability and the blocking-lines can prevent the phase error propagation effectively. Furthermore, by using the extracted closed contour to exclude the invalid areas from the phase unwrapping process, the algorithm becomes more efficient. The experiment shows the effectiveness of the new algorithm.
Quiles FJ
2007-01-01
Full Text Available We introduce and evaluate the implementations of three parallel video-sequences decorrelation algorithms. The proposed algorithms are based on the nonalternating classic three-dimensional wavelet transform (3D-WT. The parallel implementations of the algorithms are developed and tested on a shared memory system, an SGI origin 3800 supercomputer making use of a message-passing paradigm. We evaluate and analyze the performance of the implementations in terms of the response time and speed-up factor by varying the number of processors and various video coding parameters. The key points enabling the development of highly efficient implementations rely on the partitioning of the video sequences into groups of frames and a workload distribution strategy supplemented by the use of parallel I/O primitives, for better exploiting the inherent features of the application and computing platform. We also evaluate the effectiveness of our algorithms in terms of the first-order entropy.
Novel Zooming Scale Hough Transform Pattern Recognition Algorithm for the PHENIX Detector
Koblesky, Theodore
2012-03-01
Single ultra-relativistic heavy ion collisions at RHIC and the LHC and multiple overlapping proton-proton collisions at the LHC present challenges to pattern recognition algorithms for tracking in these high multiplicity environments. One must satisfy many constraints including high track finding efficiency, ghost track rejection, and CPU time and memory constraints. A novel algorithm based on a zooming scale Hough Transform is now available in Ref [1] that is optimized for efficient high speed caching and flexible in terms of its implementation. In this presentation, we detail the application of this algorithm to the PHENIX Experiment silicon vertex tracker (VTX) and show initial results from Au+Au at √sNN = 200 GeV collision data taken in 2011. We demonstrate the current algorithmic performance and also show first results for the proposed sPHENIX detector. [4pt] Ref [1] Dr. Dion, Alan. ``Helix Hough'' http://code.google.com/p/helixhough/
Sethi, Gaurav; Saini, B S
2015-12-01
This paper presents an abdomen disease diagnostic system based on the flexi-scale curvelet transform, which uses different optimal scales for extracting features from computed tomography (CT) images. To optimize the scale of the flexi-scale curvelet transform, we propose an improved genetic algorithm. The conventional genetic algorithm assumes that fit parents will likely produce the healthiest offspring that leads to the least fit parents accumulating at the bottom of the population, reducing the fitness of subsequent populations and delaying the optimal solution search. In our improved genetic algorithm, combining the chromosomes of a low-fitness and a high-fitness individual increases the probability of producing high-fitness offspring. Thereby, all of the least fit parent chromosomes are combined with high fit parent to produce offspring for the next population. In this way, the leftover weak chromosomes cannot damage the fitness of subsequent populations. To further facilitate the search for the optimal solution, our improved genetic algorithm adopts modified elitism. The proposed method was applied to 120 CT abdominal images; 30 images each of normal subjects, cysts, tumors and stones. The features extracted by the flexi-scale curvelet transform were more discriminative than conventional methods, demonstrating the potential of our method as a diagnostic tool for abdomen diseases.
Mohamad Kazem Daryabari
2011-01-01
Full Text Available The magnetizing inrush current phenomenon is a large transient condition, which occurs when a transformer is energized. The inrush current magnitude may be as high as ten times of transformer rated current that causes mal-operation of protection systems. Indeed, the similarity between signatures of Inrush current and internal fault condition make this failure. So, for safe running of a transformer, it is necessary to distinguish inrush current from fault currents. In this project, an Artificial Neural Network (ANN which is trained by two different swarm based algorithms; Gravitational Search Algorithm (GSA and Particle Swarm Optimization (PSO have been used to discriminate inrush current from fault currents in power transformers. GSA works based on gravity laws and in opposite of other swarm based algorithms, particles have identity and PSO is based on behaviors of bird flocking. Proposed approach has two general stages, in first step, obtained data from simulation have been processed and applied to ANN, and then in step two, using training data considered ANN has been trained by GSA & PSO. Proposed method has been compared with one of the common training approach which is called Back Propagation (BP and Results show that proposed method is so quick and can do discrimination very accurate.
Asem Khmag
2014-07-01
Full Text Available This study proposes novel image denoising algorithm using combination method. This method combines both Wavelet Based Denoising (WBD and Principle Component Analysis (PCA to increase the superiority of the observed image, subjectively and objectively. We exploit the important property of second generation WBD and PCA to increase the performance of our designed filter. One of the main advantages of the second generation wavelet transformation in noise reduction is its ability to keep the signal energy in small amount of coefficients in the wavelet domain. On the other hand, one of the main features of PCA is that the energy of the signal concentrates on a very few subclasses in PCA domain, while the noise’s energy equally spreads over the entire signal; this characteristic helps us to isolate the noise perfectly. Our algorithm compares favorably against several state-of-the-art filtering systems algorithms, such as Contourlet soft thresholding, Scale mixture by WT, Sparse 3D transformation and Normal shrink. In addition, the combined algorithm achieves very competitive performance compared with the traditional algorithms, especially when it comes to investigating the problem of how to preserve the fine structure of the tested image and in terms of the computational complexity reduction as well.
A WAVELET TRANSFORM BASED WATERMARKING ALGORITHM FOR PROTECTING COPYRIGHTS OF DIGITAL IMAGES
Divya A
2013-08-01
Full Text Available This paper proposes an algorithm of Digital Watermarking based on Biorthogonal Wavelet Transform. Digital Watermarking is a technique to protect the copyright of the multimedia data. The position of the watermark can be detected without using the original image by utilizing the correlation between the neighbours of wave co-efficient. The strength of Digital watermark is obtained according to the edge intensities resulting in good robust and Imperceptible. Results show that the proposed watermark algorithm is invisible and has good robustness against common image processing operations.
Burhan Ergen
2014-01-01
Full Text Available This paper proposes two edge detection methods for medical images by integrating the advantages of Gabor wavelet transform (GWT and unsupervised clustering algorithms. The GWT is used to enhance the edge information in an image while suppressing noise. Following this, the k-means and Fuzzy c-means (FCM clustering algorithms are used to convert a gray level image into a binary image. The proposed methods are tested using medical images obtained through Computed Tomography (CT and Magnetic Resonance Imaging (MRI devices, and a phantom image. The results prove that the proposed methods are successful for edge detection, even in noisy cases.
Ergen, Burhan
2014-01-01
This paper proposes two edge detection methods for medical images by integrating the advantages of Gabor wavelet transform (GWT) and unsupervised clustering algorithms. The GWT is used to enhance the edge information in an image while suppressing noise. Following this, the k-means and Fuzzy c-means (FCM) clustering algorithms are used to convert a gray level image into a binary image. The proposed methods are tested using medical images obtained through Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) devices, and a phantom image. The results prove that the proposed methods are successful for edge detection, even in noisy cases.
An oscillograms processing algorithm of a high power transformer on the basis of experimental data
Vasileva, O. V.; Budko, A. A.; Lavrinovich, A. V.
2016-04-01
The paper presents the studies on digital processing of oscillograms of the power transformer operation allowing determining the state of its windings of different types and degrees of damage. The study was carried out according to the authors' own methods using the Fourier analysis and the developed program based on the following application software packages: MathCAD and Lab View. The efficiency of the algorithm was demonstrated by the example of the waveform non-defective and defective transformers on the basis of the method of nanosecond pulses.
Local structure information by EXAFS analysis using two algorithms for Fourier transform calculation
Aldea, N; Pintea, S; Rednic, V [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania); Matei, F [University of Agricultural Sciences and Veterinary Medicine, 3-5 Calea Manastur, 400372 Cluj-Napoca (Romania); Hu Tiandou; Xie Yaning, E-mail: nicolae.aldea@itim-cj.r [Beijing Synchrotron Radiation Facilities of Beijing Electron Positron Collider National Laboratory (China)
2009-08-01
The present work is a comparison study between different algorithms of Fourier transform for obtaining very accurate local structure results using Extended X-ray Absorption Fine Structure technique. In this paper we focus on the local structural characteristics of supported nickel catalysts and Fe{sub 3}O{sub 4} core-shell nanocomposites. The radial distribution function could be efficiently calculated by the fast Fourier transform when the coordination shells are well separated while the Filon quadrature gave remarkable results for close-shell coordination.
Fast algorithm of byte-to-byte wavelet transform for image compression applications
Pogrebnyak, Oleksiy B.; Sossa Azuela, Juan H.; Ramirez, Pablo M.
2002-11-01
A new fast algorithm of 2D DWT transform is presented. The algorithm operates on byte represented images and performs image transformation with the Cohen-Daubechies-Feauveau wavelet of the second order. It uses the lifting scheme for the calculations. The proposed algorithm is based on the "checkerboard" computation scheme for non-separable 2D wavelet. The problem of data extension near the image borders is resolved computing 1D Haar wavelet in the vicinity of the borders. With the checkerboard splitting, at each level of decomposition only one detail image is produced that simplify the further analysis for data compression. The calculations are rather simple, without any floating point operation allowing the implementation of the designed algorithm in fixed point DSP processors for fast, near real time processing. The proposed algorithm does not possesses perfect restoration of the processed data because of rounding that is introduced at each level of decomposition/restoration to perform operations with byte represented data. The designed algorithm was tested on different images. The criterion to estimate quantitatively the quality of the restored images was the well known PSNR. For the visual quality estimation the error maps between original and restored images were calculated. The obtained simulation results show that the visual and quantitative quality of the restored images is degraded with number of decomposition level increasing but is sufficiently high even after 6 levels. The introduced distortion are concentrated in the vicinity of high spatial activity details and are absent in the homogeneous regions. The designed algorithm can be used for image lossy compression and in noise suppression applications.
Li, Zili; Xia, Xuezhi; Zhu, Guangxi; Zhu, Yaoting
2004-03-01
The principle to construct G&IBMR virtual scene based on stereo panorama with binocular stereovision was put forward. Closed cubic B-splines have been used for content-based segmentation to virtual objects of stereo panorama and all objects in current viewing frustum would be ordered in current object linked list (COLL) by their depth information. The formula has been educed to calculate the depth information of a point in virtual scene by the parallax based on a parallel binocular vision model. A bilinear interpolation algorithm has been submitted to deform the segmentation template and take image splicing between three key positions. We also use the positional and directional transformation of binocular virtual camera bound to user avatar to drive the transformation of stereo panorama so as to achieve real-time consistency about perspective relationship and image masking. The experimental result has shown that the algorithm in this paper is effective and feasible.
Efficient Algorithms for the Discrete Gabor Transform with a Long Fir Window
Søndergaard, Peter Lempel
2012-01-01
The Discrete Gabor Transform (DGT) is the most commonly used signal transform for signal analysis and synthesis using a linear frequency scale. The development of the Linear Time-Frequency Analysis Toolbox (LTFAT) has been based on a detailed study of many variants of the relevant algorithms....... As a side result of these systematic developments of the subject, two new methods are presented here. Comparisons are made with respect to the computational complexity, and the running time of optimised implementations in the C programming language. The new algorithms have the lowest known computational...... complexity and running time when a long FIR window is used. The implementations are freely available for download. By summarizing general background information on the state of the art, this article can also be seen as a research survey, sharing with the readers experience in the numerical work in Gabor...
A New Algorithm for Two—Dimensional Line Clipping via Geometric Transformation
汪灏泓; 吴瑞迅; 等
1998-01-01
Line segment clipping is a basic operation of the visualization process in computer graphics.So far there exist four computational models for clipping a line segment against a window,(1)the encoding,(2)the parametric,(3)the geometric transforma tion,and (4)the parallel cutting.This paper presents an algorithm that is based on the third method.By making use of symmetric properties of a window and transformation operations,both endpoints of a line segment are transformed,so that the basic cases are reduced into two that can be easily handled,thus the problems in NLN and AS where there are too many sub-procedure calls and basic cases that are difficult to deal with are tackled.Both analytical and experimental results from random input data show that the algorithm is better than other developed ones,in view of the speed and the number of operations.
He, Hongxing; Fang, Hengrui [Department of Physics and Texas Center for Superconductivity, University of Houston, Houston, Texas 77204 (United States); Miller, Mitchell D. [Department of BioSciences, Rice University, Houston, Texas 77005 (United States); Phillips, George N. Jr [Department of BioSciences, Rice University, Houston, Texas 77005 (United States); Department of Chemistry, Rice University, Houston, Texas 77005 (United States); Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Su, Wu-Pei, E-mail: wpsu@uh.edu [Department of Physics and Texas Center for Superconductivity, University of Houston, Houston, Texas 77204 (United States)
2016-07-15
An iterative transform algorithm is proposed to improve the conventional molecular-replacement method for solving the phase problem in X-ray crystallography. Several examples of successful trial calculations carried out with real diffraction data are presented. An iterative transform method proposed previously for direct phasing of high-solvent-content protein crystals is employed for enhancing the molecular-replacement (MR) algorithm in protein crystallography. Target structures that are resistant to conventional MR due to insufficient similarity between the template and target structures might be tractable with this modified phasing method. Trial calculations involving three different structures are described to test and illustrate the methodology. The relationship of the approach to PHENIX Phaser-MR and MR-Rosetta is discussed.
A frequency measurement algorithm for non-stationary signals by using wavelet transform
Seo, Seong-Heon; Oh, Dong Keun
2016-11-01
Scalogram is widely used to measure instantaneous frequencies of non-stationary signals. However, the basic property of the scalogram is observed only for stationary sinusoidal functions. A property of the scalogram for non-stationary signal is analytically derived in this paper. Based on the property, a new frequency measurement algorithm is proposed. In addition, a filter that can separate two similar frequency signals is developed based on the wavelet transform.
Sang, Jun; Zhao, Jun; Xiang, Zhili; Cai, Bin; Xiang, Hong
2015-08-05
Gyrator transform has been widely used for image encryption recently. For gyrator transform-based image encryption, the rotation angle used in the gyrator transform is one of the secret keys. In this paper, by analyzing the properties of the gyrator transform, an improved particle swarm optimization (PSO) algorithm was proposed to search the rotation angle in a single gyrator transform. Since the gyrator transform is continuous, it is time-consuming to exhaustedly search the rotation angle, even considering the data precision in a computer. Therefore, a computational intelligence-based search may be an alternative choice. Considering the properties of severe local convergence and obvious global fluctuations of the gyrator transform, an improved PSO algorithm was proposed to be suitable for such situations. The experimental results demonstrated that the proposed improved PSO algorithm can significantly improve the efficiency of searching the rotation angle in a single gyrator transform. Since gyrator transform is the foundation of image encryption in gyrator transform domains, the research on the method of searching the rotation angle in a single gyrator transform is useful for further study on the security of such image encryption algorithms.
Jun Sang
2015-08-01
Full Text Available Gyrator transform has been widely used for image encryption recently. For gyrator transform-based image encryption, the rotation angle used in the gyrator transform is one of the secret keys. In this paper, by analyzing the properties of the gyrator transform, an improved particle swarm optimization (PSO algorithm was proposed to search the rotation angle in a single gyrator transform. Since the gyrator transform is continuous, it is time-consuming to exhaustedly search the rotation angle, even considering the data precision in a computer. Therefore, a computational intelligence-based search may be an alternative choice. Considering the properties of severe local convergence and obvious global fluctuations of the gyrator transform, an improved PSO algorithm was proposed to be suitable for such situations. The experimental results demonstrated that the proposed improved PSO algorithm can significantly improve the efficiency of searching the rotation angle in a single gyrator transform. Since gyrator transform is the foundation of image encryption in gyrator transform domains, the research on the method of searching the rotation angle in a single gyrator transform is useful for further study on the security of such image encryption algorithms.
IMPROVEMENT OF ANOMALY DETECTION ALGORITHMS IN HYPERSPECTRAL IMAGES USING DISCRETE WAVELET TRANSFORM
Kamal Jamshidi
2012-01-01
Full Text Available Recently anomaly detection (AD has become an important application for target detection in hyperspectralremotely sensed images. In many applications, in addition to high accuracy of detection we need a fast andreliable algorithm as well. This paper presents a novel method to improve the performance of current ADalgorithms. The proposed method first calculates Discrete Wavelet Transform (DWT of every pixel vectorof image using Daubechies4 wavelet. Then, AD algorithm performs on four bands of “Wavelet transform”matrix which are the approximation of main image. In this research some benchmark AD algorithmsincluding Local RX, DWRX and DWEST have been implemented on Airborne Visible/Infrared ImagingSpectrometer (AVIRIS hyperspectral datasets. Experimental results demonstrate significant improvementof runtime in proposed method. In addition, this method improves the accuracy of AD algorithms becauseof DWT’s power in extracting approximation coefficients of signal, which contain the main behaviour ofsignal, and abandon the redundant information in hyperspectral image data.
Tan, Ru-Chao; Lei, Tong; Zhao, Qing-Min; Gong, Li-Hua; Zhou, Zhi-Hong
2016-12-01
To improve the slow processing speed of the classical image encryption algorithms and enhance the security of the private color images, a new quantum color image encryption algorithm based on a hyper-chaotic system is proposed, in which the sequences generated by the Chen's hyper-chaotic system are scrambled and diffused with three components of the original color image. Sequentially, the quantum Fourier transform is exploited to fulfill the encryption. Numerical simulations show that the presented quantum color image encryption algorithm possesses large key space to resist illegal attacks, sensitive dependence on initial keys, uniform distribution of gray values for the encrypted image and weak correlation between two adjacent pixels in the cipher-image.
A Gillespie algorithm for non-Markovian stochastic processes: Laplace transform approach
Masuda, Naoki
2016-01-01
The Gillespie algorithm provides statistically exact methods to simulate stochastic dynamics modelled as interacting sequences of discrete events including systems of biochemical reactions or earthquakes, networks of queuing processes or spiking neurons, and epidemic and opinion formation processes on social networks. Empirically, inter-event times of various human activities, in particular human communication, and some natural phenomena are often distributed according to long-tailed distributions. The Gillespie algorithm and its extant variants either assume the Poisson process, which produces exponentially distributed inter-event times, not long-tailed distributions, assume particular functional forms for time courses of the event rate, or works for non-Poissonian renewal processes including the case of long-tailed distributions of inter-event times but at a high computational cost. In the present study, we propose an innovative Gillespie algorithm for renewal processes on the basis of the Laplace transform...
A. Al-Haj
2008-01-01
Full Text Available The excellent spatial localization, frequency spread and multi-resolution characteristics of the Discrete Wavelets Transform (DWT, which were similar to the theoretical models of the human visual system, facilitated the development of many imperceptible and robust DWT-based watermarking algorithms. There had been extremely few proposed algorithms on optimized DWT-based image watermarking that can simultaneously provide perceptual transparency and robustness since these two watermarking requirements are conflicting, in this study we treat the DWT-based image watermarking problem as an optimization problem and solve it using genetic algorithms. We demonstrate through the experimental results we obtained that optimal DWT-based image watermarking can be achieved only if watermarking has been applied at specific wavelet sub-bands and by using specific watermark-amplification values.
Silveira, L.M.; Kamon, M.; Elfadel, I.; White, J. [Massachusetts Inst. of Technology, Cambridge, MA (United States)
1996-12-31
Model order reduction based on Krylov subspace iterative methods has recently emerged as a major tool for compressing the number of states in linear models used for simulating very large physical systems (VLSI circuits, electromagnetic interactions). There are currently two main methods for accomplishing such a compression: one is based on the nonsymmetric look-ahead Lanczos algorithm that gives a numerically stable procedure for finding Pade approximations, while the other is based on a less well characterized Arnoldi algorithm. In this paper, we show that for certain classes of generalized state-space systems, the reduced-order models produced by a coordinate-transformed Arnoldi algorithm inherit the stability of the original system. Complete Proofs of our results will be given in the final paper.
Natural majorization of the Quantum Fourier Transformation in phase-estimation algorithms
Orus, R; Martín-Delgado, M A; Orus, Roman; Latorre, Jose I.; Martin-Delgado, Miguel A.
2002-01-01
We prove that majorization relations hold step by step in the Quantum Fourier Transformation (QFT) for phase-estimation algorithms considered in the canonical decomposition. Our result relies on the fact that states which are mixed by Hadamard operators at any stage of the computation only differ by a phase. This property is a consequence of the structure of the initial state and of the QFT, based on controlled-phase operators and a single action of a Hadamard gate per qubit. As a consequence, Hadamard gates order the probability distribution associated to the quantum state, whereas controlled-phase operators carry all the entanglement but are immaterial to majorization. We also prove that majorization in phase-estimation algorithms follows in a most natural way from unitary evolution, unlike its counterpart in Grover's algorithm.
Feng, Yanqiu; Song, Yanli; Wang, Cong; Xin, Xuegang; Feng, Qianjin; Chen, Wufan
2013-10-01
To develop and test a new algorithm for fast direct Fourier transform (DrFT) reconstruction of MR data on non-Cartesian trajectories composed of lines with equally spaced points. The DrFT, which is normally used as a reference in evaluating the accuracy of other reconstruction methods, can reconstruct images directly from non-Cartesian MR data without interpolation. However, DrFT reconstruction involves substantially intensive computation, which makes the DrFT impractical for clinical routine applications. In this article, the Chirp transform algorithm was introduced to accelerate the DrFT reconstruction of radial and Periodically Rotated Overlapping ParallEL Lines with Enhanced Reconstruction (PROPELLER) MRI data located on the trajectories that are composed of lines with equally spaced points. The performance of the proposed Chirp transform algorithm-DrFT algorithm was evaluated by using simulation and in vivo MRI data. After implementing the algorithm on a graphics processing unit, the proposed Chirp transform algorithm-DrFT algorithm achieved an acceleration of approximately one order of magnitude, and the speed-up factor was further increased to approximately three orders of magnitude compared with the traditional single-thread DrFT reconstruction. Implementation the Chirp transform algorithm-DrFT algorithm on the graphics processing unit can efficiently calculate the DrFT reconstruction of the radial and PROPELLER MRI data. Copyright © 2012 Wiley Periodicals, Inc.
The Application Wavelet Transform Algorithm in Testing ADC Effective Number of Bits
Emad A. Awada
2013-10-01
Full Text Available In evaluating Analog to Digital Convertors, many parameters are checked for performance and error rate.One of these parameters is the device Effective Number of Bits. In classical testing of Effective Number ofBits, testing is based on signal to noise components ratio (SNR, whose coefficients are driven viafrequency domain (Fourier Transform of ADC’s output signal. Such a technique is extremely sensitive tonoise and require large number of data samples. That is, longer and more complex testing process as thedevice under test increases in resolutions. Meanwhile, a new time – frequency domain approach (known asWavelet transform is proposed to measure and analyze Analog-to-Digital Converters parameter ofEffective Number of Bits with less complexity and fewer data samples.In this work, the algorithm of Wavelet transform was used to estimate worst case Effective Number of Bitsand compare the new testing results with classical testing methods. Such an algorithm, Wavelet transform,have shown DSP testing process improvement in terms of time and computations complexity based on itsspecial properties of multi-resolutions.
Bigdeli Mehdi
2016-03-01
Full Text Available Transformers are one of the most important components of the power system. It is important to maintain and assess the condition. Transformer lifetime depends on the life of its insulation and insulation life is also strongly influenced by moisture in the insulation. Due to importance of this issue, in this paper a new method is introduced for determining the moisture content of the transformer insulation system using dielectric response analysis in the frequency domain based on artificial bee colony algorithm. First, the master curve of dielectric response is modeled. Then, using proposed method the master curve and the measured dielectric response curves are compared. By analyzing the results of the comparison, the moisture content of paper insulation, electrical conductivity of the insulating oil and dielectric model dimensions are determined. Finally, the proposed method is applied to several practical samples to demonstrate its capabilities compared with the well-known conventional method.
Tokunaga, Yoshitaka
This paper presents estimation techniques of machine parameters for power transformer using design procedure of transformer and genetic algorithm with real coding. Especially, it is very difficult to obtain machine parameters for transformers in customers' facilities. Using estimation techniques, machine parameters could be calculated from the only nameplate data of these transformers. Subsequently, EMTP-ATP simulation of the inrush current was carried out using machine parameters estimated by techniques developed in this study and simulation results were reproduced measured waveforms.
A new adaptive algorithm for image denoising based on curvelet transform
Chen, Musheng; Cai, Zhishan
2013-10-01
The purpose of this paper is to study a method of denoising images corrupted with additive white Gaussian noise. In this paper, the application of the time invariant discrete curvelet transform for noise reduction is considered. In curvelet transform, the frame elements are indexed by scale, orientation and location parameters. It is designed to represent edges and the singularities along curved paths more efficiently than the wavelet transform. Therefore, curvelet transform can get better results than wavelet method in image denoising. In general, image denoising imposes a compromise between noise reduction and preserving significant image details. To achieve a good performance in this respect, an efficient and adaptive image denoising method based on curvelet transform is presented in this paper. Firstly, the noisy image is decomposed into many levels to obtain different frequency sub-bands by curvelet transform. Secondly, efficient and adaptive threshold estimation based on generalized Gaussian distribution modeling of sub-band coefficients is used to remove the noisy coefficients. The choice of the threshold estimation is carried out by analyzing the standard deviation and threshold. Ultimately, invert the multi-scale decomposition to reconstruct the denoised image. Here, to prove the performance of the proposed method, the results are compared with other existent algorithms such as hard and soft threshold based on wavelet. The simulation results on several testing images indicate that the proposed method outperforms the other methods in peak signal to noise ratio and keeps better visual in edges information reservation as well. The results also suggest that curvelet transform can achieve a better performance than the wavelet transform in image denoising.
Watermarking algorithm based on Her transform%Her变换的数字水印算法
王立鹏
2012-01-01
Most transformations used for digital watermarking in transformation domain are orthogonal transformations, such as DCT and DWT. Three types of orthogonal transformation with excellent performance are found by studying three systems of orthogonal functions： Haar function system, Haar type function system and Walsh function system. Her transformation is one of the three transformations. Her function system can not be used directly in digital watermarking as DCT matrix being used, since Her matrix of Her function system is not normalized orthogonal matrix. The corresponding discrete matrix is obtained by sampling Her continuous functions, and successfully used in digital watermarking with a series of experiments and theoretical analysis. A digital watermarking algorithm based on Her transformation is proposed. Experimental results show that the algorithm is simple and good at perceptual transparency as well as robustness of watermarking extraction. In addition, the experimental results of comparing with the traditional DCT watermarking show that this algorithm is of good robustness against noise and filtering.%经对目前数字水印变换域算法的研究，发现常用的变换大多都是正交变换（如DCT和DwT等）。作者通过对Haar函数系、Haar类函数系和Walsh函数系这三大类正交函数系的研究，找到了与之对应的三类性能优良的正交变换，Her类正交变换就是其中的一种。由于Her函数系所对应的Her矩阵不是归一化的正交矩阵，所以不能像DCT等矩阵一样直接应用于数字水印技术，通过对Her连续函数的采样，得出了其对应的离散矩阵，然后通过一系列的实验数据和理论证明，成功的将其应用于数字水印中。最后，提出一种新颖的、鲁棒的Her域盲水印算法。实验结果表明该算法计算简单，且具有良好的不可见性，通过与传统DCT水印的对比表明，该算法在抵抗噪声和和滤波等方面具有较强的鲁棒性。
Lee, Dong-Hoon; Lee, Do-Wan; Han, Bong-Soo
2016-01-01
The purpose of this study is an application of scale invariant feature transform (SIFT) algorithm to stitch the cervical-thoracic-lumbar (C-T-L) spine magnetic resonance (MR) images to provide a view of the entire spine in a single image. All MR images were acquired with fast spin echo (FSE) pulse sequence using two MR scanners (1.5 T and 3.0 T). The stitching procedures for each part of spine MR image were performed and implemented on a graphic user interface (GUI) configuration. Moreover, the stitching process is performed in two categories; manual point-to-point (mPTP) selection that performed by user specified corresponding matching points, and automated point-to-point (aPTP) selection that performed by SIFT algorithm. The stitched images using SIFT algorithm showed fine registered results and quantitatively acquired values also indicated little errors compared with commercially mounted stitching algorithm in MRI systems. Our study presented a preliminary validation of the SIFT algorithm application to MRI spine images, and the results indicated that the proposed approach can be performed well for the improvement of diagnosis. We believe that our approach can be helpful for the clinical application and extension of other medical imaging modalities for image stitching.
Chouakri, S. A.; Djaafri, O.; Taleb-Ahmed, A.
2013-08-01
We present in this work an algorithm for electrocardiogram (ECG) signal compression aimed to its transmission via telecommunication channel. Basically, the proposed ECG compression algorithm is articulated on the use of wavelet transform, leading to low/high frequency components separation, high order statistics based thresholding, using level adjusted kurtosis value, to denoise the ECG signal, and next a linear predictive coding filter is applied to the wavelet coefficients producing a lower variance signal. This latter one will be coded using the Huffman encoding yielding an optimal coding length in terms of average value of bits per sample. At the receiver end point, with the assumption of an ideal communication channel, the inverse processes are carried out namely the Huffman decoding, inverse linear predictive coding filter and inverse discrete wavelet transform leading to the estimated version of the ECG signal. The proposed ECG compression algorithm is tested upon a set of ECG records extracted from the MIT-BIH Arrhythmia Data Base including different cardiac anomalies as well as the normal ECG signal. The obtained results are evaluated in terms of compression ratio and mean square error which are, respectively, around 1:8 and 7%. Besides the numerical evaluation, the visual perception demonstrates the high quality of ECG signal restitution where the different ECG waves are recovered correctly.
Qian, Jinfang; Zhang, Changjiang
2014-11-01
An efficient algorithm based on continuous wavelet transform combining with pre-knowledge, which can be used to detect the defect of glass bottle mouth, is proposed. Firstly, under the condition of ball integral light source, a perfect glass bottle mouth image is obtained by Japanese Computar camera through the interface of IEEE-1394b. A single threshold method based on gray level histogram is used to obtain the binary image of the glass bottle mouth. In order to efficiently suppress noise, moving average filter is employed to smooth the histogram of original glass bottle mouth image. And then continuous wavelet transform is done to accurately determine the segmentation threshold. Mathematical morphology operations are used to get normal binary bottle mouth mask. A glass bottle to be detected is moving to the detection zone by conveyor belt. Both bottle mouth image and binary image are obtained by above method. The binary image is multiplied with normal bottle mask and a region of interest is got. Four parameters (number of connected regions, coordinate of centroid position, diameter of inner cycle, and area of annular region) can be computed based on the region of interest. Glass bottle mouth detection rules are designed by above four parameters so as to accurately detect and identify the defect conditions of glass bottle. Finally, the glass bottles of Coca-Cola Company are used to verify the proposed algorithm. The experimental results show that the proposed algorithm can accurately detect the defect conditions of the glass bottles and have 98% detecting accuracy.
Iterative Fourier transform algorithm: different approaches to diffractive optical element design
Skeren, Marek; Richter, Ivan; Fiala, Pavel
2002-10-01
This contribution focuses on the study and comparison of different design approaches for designing phase-only diffractive optical elements (PDOEs) for different possible applications in laser beam shaping. Especially, new results and approaches, concerning the iterative Fourier transform algorithm, are analyzed, implemented, and compared. Namely, various approaches within the iterative Fourier transform algorithm (IFTA) are analyzed for the case of phase-only diffractive optical elements with quantizied phase levels (either binary or multilevel structures). First, the general scheme of the IFTA iterative approach with partial quantization is briefly presented and discussed. Then, the special assortment of the general IFTA scheme is given with respect to quantization constraint strategies. Based on such a special classification, the three practically interesting approaches are chosen, further-analyzed, and compared to eachother. The performance of these algorithms is compared in detail in terms of the signal-to-noise ratio characteristic developments with respect to the numberof iterations, for various input diffusive-type objects chose. Also, the performance is documented on the complex spectra developments for typical computer reconstruction results. The advantages and drawbacks of all approaches are discussed, and a brief guide on the choice of a particular approach for typical design tasks is given. Finally, the two ways of amplitude elimination within the design procedure are considered, namely the direct elimination and partial elimination of the amplitude of the complex hologram function.
Juan F P J Abascal
Full Text Available Respiratory gating helps to overcome the problem of breathing motion in cardiothoracic small-animal imaging by acquiring multiple images for each projection angle and then assigning projections to different phases. When this approach is used with a dose similar to that of a static acquisition, a low number of noisy projections are available for the reconstruction of each respiratory phase, thus leading to streak artifacts in the reconstructed images. This problem can be alleviated using a prior image constrained compressed sensing (PICCS algorithm, which enables accurate reconstruction of highly undersampled data when a prior image is available. We compared variants of the PICCS algorithm with different transforms in the prior penalty function: gradient, unitary, and wavelet transform. In all cases the problem was solved using the Split Bregman approach, which is efficient for convex constrained optimization. The algorithms were evaluated using simulations generated from data previously acquired on a micro-CT scanner following a high-dose protocol (four times the dose of a standard static protocol. The resulting data were used to simulate scenarios with different dose levels and numbers of projections. All compressed sensing methods performed very similarly in terms of noise, spatiotemporal resolution, and streak reduction, and filtered back-projection was greatly improved. Nevertheless, the wavelet domain was found to be less prone to patchy cartoon-like artifacts than the commonly used gradient domain.
Multiple Harmonics Fitting Algorithms Applied to Periodic Signals Based on Hilbert-Huang Transform
Hui Wang
2013-01-01
Full Text Available A new generation of multipurpose measurement equipment is transforming the role of computers in instrumentation. The new features involve mixed devices, such as kinds of sensors, analog-to-digital and digital-to-analog converters, and digital signal processing techniques, that are able to substitute typical discrete instruments like multimeters and analyzers. Signal-processing applications frequently use least-squares (LS sine-fitting algorithms. Periodic signals may be interpreted as a sum of sine waves with multiple frequencies: the Fourier series. This paper describes a new sine fitting algorithm that is able to fit a multiharmonic acquired periodic signal. By means of a “sinusoidal wave” whose amplitude and phase are both transient, the “triangular wave” can be reconstructed on the basis of Hilbert-Huang transform (HHT. This method can be used to test effective number of bits (ENOBs of analog-to-digital converter (ADC, avoiding the trouble of selecting initial value of the parameters and working out the nonlinear equations. The simulation results show that the algorithm is precise and efficient. In the case of enough sampling points, even under the circumstances of low-resolution signal with the harmonic distortion existing, the root mean square (RMS error between the sampling data of original “triangular wave” and the corresponding points of fitting “sinusoidal wave” is marvelously small. That maybe means, under the circumstances of any periodic signal, that ENOBs of high-resolution ADC can be tested accurately.
Some Integral Relations of Hankel Transform Type and Applications to Elasticity Theory
Krenk, Steen
1982-01-01
of a complicated bounded kernel. The static problem of a circular crack in an infinite elastic body under general loads is used to illustrate vector boundary conditions leading to two coupled integral equations, while the problem of a vibrating flexible circular plate in frictionless contact with an elastic half...
Yanhui Li
2014-01-01
Full Text Available This paper investigates the Hankel norm filter design problem for stochastic time-delay systems, which are represented by Takagi-Sugeno (T-S fuzzy model. Motivated by the parallel distributed compensation (PDC technique, a novel filtering error system is established. The objective is to design a suitable filter that guarantees the corresponding filtering error system to be mean-square asymptotically stable and to have a specified Hankel norm performance level γ. Based on the Lyapunov stability theory and the Itô differential rule, the Hankel norm criterion is first established by adopting the integral inequality method, which can make some useful efforts in reducing conservativeness. The Hankel norm filtering problem is casted into a convex optimization problem with a convex linearization approach, which expresses all the conditions for the existence of admissible Hankel norm filter as standard linear matrix inequalities (LMIs. The effectiveness of the proposed method is demonstrated via a numerical example.
何建军; 任震; 黄雯莹; 周宏; 林涛
1999-01-01
With a complex wavelet function, a new real-time recursive algorithm of wavelet transform (WT) is analyzed in detail. Compared with the existing recursive algorithm in two directions, the computing time is greatly redueed in response to faults signals in power systems, and the same recursive algorithm can be generalized to other wavelet functions. With the phases and magnitudes of complex WT coefficients under the fast recursive algorithm, a method to detect faults signals of power systems is presented. Lastly, the analyzing results of some signals show that it is effective and practical for the complex wavelet and its real-time recursive algorithm to detect faults of power systems.
Zielinski, B.; Patorski, K.
2010-06-01
The aim of this paper is to analyze 2D fringe pattern denoising performed by two chosen methods based on quasi-1D two-arm spin filter and 2D discrete wavelet transform (DWT) signal decomposition and thresholding. The ultimate aim of this comparison is to estimate which algorithm is better suited for high-accuracy measurements by phase shifting interferometry (PSI) with the phase step evaluation using the lattice site approach. The spin filtering method proposed by Yu et al. (1994) was designed to minimize possible fringe blur and distortion. The 2D DWT also presents such features due to a lossless nature of the signal wavelet decomposition. To compare both methods, a special 2D histogram introduced by Gutman and Weber (1998) is used to evaluate intensity errors introduced by each of the presented algorithms.
Research of converter transformer fault diagnosis based on improved PSO-BP algorithm
Long, Qi; Guo, Shuyong; Li, Qing; Sun, Yong; Li, Yi; Fan, Youping
2017-09-01
To overcome those disadvantages that BP (Back Propagation) neural network and conventional Particle Swarm Optimization (PSO) converge at the global best particle repeatedly in early stage and is easy trapped in local optima and with low diagnosis accuracy when being applied in converter transformer fault diagnosis, we come up with the improved PSO-BP neural network to improve the accuracy rate. This algorithm improves the inertia weight Equation by using the attenuation strategy based on concave function to avoid the premature convergence of PSO algorithm and Time-Varying Acceleration Coefficient (TVAC) strategy was adopted to balance the local search and global search ability. At last the simulation results prove that the proposed approach has a better ability in optimizing BP neural network in terms of network output error, global searching performance and diagnosis accuracy.
Abibullaev, Berdakh; An, Jinung
2012-12-01
Recent advances in neuroimaging demonstrate the potential of functional near-infrared spectroscopy (fNIRS) for use in brain-computer interfaces (BCIs). fNIRS uses light in the near-infrared range to measure brain surface haemoglobin concentrations and thus determine human neural activity. Our primary goal in this study is to analyse brain haemodynamic responses for application in a BCI. Specifically, we develop an efficient signal processing algorithm to extract important mental-task-relevant neural features and obtain the best possible classification performance. We recorded brain haemodynamic responses due to frontal cortex brain activity from nine subjects using a 19-channel fNIRS system. Our algorithm is based on continuous wavelet transforms (CWTs) for multi-scale decomposition and a soft thresholding algorithm for de-noising. We adopted three machine learning algorithms and compared their performance. Good performance can be achieved by using the de-noised wavelet coefficients as input features for the classifier. Moreover, the classifier performance varied depending on the type of mother wavelet used for wavelet decomposition. Our quantitative results showed that CWTs can be used efficiently to extract important brain haemodynamic features at multiple frequencies if an appropriate mother wavelet function is chosen. The best classification results were obtained by a specific combination of input feature type and classifier.
Musatenko, Yurij S.; Kurashov, Vitalij N.
1998-10-01
The paper presents improved version of our new method for compression of correlated image sets Optimal Image Coding using Karhunen-Loeve transform (OICKL). It is known that Karhunen-Loeve (KL) transform is most optimal representation for such a purpose. The approach is based on fact that every KL basis function gives maximum possible average contribution in every image and this contribution decreases most quickly among all possible bases. So, we lossy compress every KL basis function by Embedded Zerotree Wavelet (EZW) coding with essentially different loss that depends on the functions' contribution in the images. The paper presents new fast low memory consuming algorithm of KL basis construction for compression of correlated image ensembles that enable our OICKL system to work on common hardware. We also present procedure for determining of optimal losses of KL basic functions caused by compression. It uses modified EZW coder which produce whole PSNR (bitrate) curve during the only compression pass.
Esther A.K James
2012-01-01
Full Text Available Problem statement: The paper addresses the face recognition problem by proposing Weighted Fuzzy Fisherface (WFF technique using Biorthogonal Transformation. The Weighted Fuzzy Fisherface technique is an extension of Fisher Face technique by introducing fuzzy class membership to each training sample in calculating the scatter matrices. Approach: In weighted fuzzy fisherface method, the weight emphasizes classes that are close together and deemphasizes the classes that are far away from each other. Results: The proposed method is more advantageous for the classification task and its accuracy is improved. Also with the performance measures False Acceptance Rate (FAR, False Rejection Rate (FRR and Equal Error Rate (EER are calculated. Conclusion: Weighted fuzzy fisherface algorithm using wavelet transform can effectively and efficiently used for face recognition and its accuracy is improved.
[A peak recognition algorithm designed for chromatographic peaks of transformer oil].
Ou, Linjun; Cao, Jian
2014-09-01
In the field of the chromatographic peak identification of the transformer oil, the traditional first-order derivative requires slope threshold to achieve peak identification. In terms of its shortcomings of low automation and easy distortion, the first-order derivative method was improved by applying the moving average iterative method and the normalized analysis techniques to identify the peaks. Accurate identification of the chromatographic peaks was realized through using multiple iterations of the moving average of signal curves and square wave curves to determine the optimal value of the normalized peak identification parameters, combined with the absolute peak retention times and peak window. The experimental results show that this algorithm can accurately identify the peaks and is not sensitive to the noise, the chromatographic peak width or the peak shape changes. It has strong adaptability to meet the on-site requirements of online monitoring devices of dissolved gases in transformer oil.
Zhai, Guangtao; Sun, Fengrong; Song, Haohao; Zhang, Mingqiang; Liu, Li; Wang, Changyu
2003-09-01
The modulus maxima of a signal's wavelet transform on different levels contain important information of the signal, which can be help to construct wavelet coefficients. A fast algorithm based on Hermite interpolation polynomial for reconstructing signal from its wavelet transform maxima is proposed in this paper. An implementation of this algorithm in medical image enhancement is also discussed. Numerical experiments have shown that compared with the Alternating Projection algorithm proposed by Mallat, this reconstruction algorithm is simpler, more efficient, and at the same time keeps high reconstruction Signal to Noise Ratio. When applied to the image contract enhancement, the computing time of this algorithm is much less compared with the one using Mallat's Alternative Projection, and the results are almost the same, so it is a practical fast reconstruction algorithm.
Shinbori, Eiji; Takagi, Mikio
1992-11-01
A new image magnification method, called 'IM-GPDCT' (image magnification applying the Gerchberg-Papoulis (GP) iterative algorithm with discrete cosine transform (DCT)), is described and its performance evaluated. This method markedly improves image quality of a magnified image using a concept which restores the spatial high frequencies which are conventionally lost due to use of a low pass filter. These frequencies are restored using two known constraints applied during iterative DCT: (1) correct information in a passband is known and (2) the spatial extent of an image is finite. Simulation results show that the IM- GPDCT outperforms three conventional interpolation methods from both a restoration error and image quality standpoint.
A NOVEL ALGORITHM OF MULTI-SENSOR IMAGE FUSION BASED ON WAVELET PACKET TRANSFORM
无
2006-01-01
In order to enhance the image information from multi-sensor and to improve the abilities of theinformation analysis and the feature extraction, this letter proposed a new fusion approach in pixel level bymeans of the Wavelet Packet Transform (WPT). The WPT is able to decompose an image into low frequencyband and high frequency band in higher scale. It offers a more precise method for image analysis than Wave-let Transform (WT). Firstly, the proposed approach employs HIS (Hue, Intensity, Saturation) transform toobtain the intensity component of CBERS (China-Brazil Earth Resource Satellite) multi-spectral image. ThenWPT transform is employed to decompose the intensity component and SPOT (Systeme Pour I'Observationde la Therre ) image into low frequency band and high frequency band in three levels. Next, two high fre-quency coefficients and low frequency coefficients of the images are combined by linear weighting strategies.Finally, the fused image is obtained with inverse WPT and inverse HIS. The results show the new approachcan fuse details of input image successfully, and thereby can obtain a more satisfactory result than that of HM(Histogram Matched)-based fusion algorithm and WT-based fusion approach.
Cross-correlation of bio-signals using continuous wavelet transform and genetic algorithm.
Sukiennik, Piotr; Białasiewicz, Jan T
2015-05-30
Continuous wavelet transform allows to obtain time-frequency representation of a signal and analyze short-lived temporal interaction of concurrent processes. That offers good localization in both time and frequency domain. Scalogram and coscalogram analysis of two signal interaction dynamics gives an indication of the cross-correlation of analyzed signals in both domains. We have used genetic algorithm with a fitness function based on signals convolution to find time delay between investigated signals. Two methods of cross-correlation are proposed: one that finds single delay for analyzed signals, and one returns a vector of delay values for each of wavelet transform sub-band center frequencies. Algorithms were implemented using MATLAB. We have extracted the data of simultaneously recorded encephalogram and arterial blood pressure and have investigated their interaction dynamics. We found time delay whose value cannot be precisely determined by scalograms and coscalogram inspection. The biomedical signals used come from MIMIC database. Cross-correlation of two complex signals is commonly performed using fast Fourier transform. It works well for signals with invariant frequency content. We have determined the time delay between analyzed signals using wavelet scalograms and we have accordingly shifted one of them, aligning associated events. Their coscalogram indicates the cross-correlation of the associated events. Introducing new methods of wavelet transform in cross-correlation analysis has proven to be beneficial to the gain of the information about process interaction. Introduced solutions could be used to reason about causality between processes and gain bigger insight regarding analyzed systems. Copyright © 2015 Elsevier B.V. All rights reserved.
Bang, Jeongho; Yoo, Seokwon
2014-01-01
We propose a genetic-algorithm-based method to find the unitary transformations for any desired quantum computation. We formulate a simple genetic algorithm by introducing the "genetic parameter vector" of the unitary transformations to be found. In the genetic algorithm process, all components of the genetic parameter vectors are supposed to evolve to the solution parameters of the unitary transformations. We apply our method to find the optimal unitary transformations and to generalize the ...
Optical multiple-image encryption based on phase encoding algorithm in the Fresnel transform domain
Huang, Jian-Ji; Hwang, Hone-Ene; Chen, Chun-Yuan; Chen, Ching-Mu
2012-10-01
A novel method of the optical multiple-image encryption based on the modified Gerchberg-Saxton algorithm (MGSA) is presented. This proposed method with an architecture of two adjacent phase only functions (POFs) in the Fresnel transform (FrT) domain that can extremely increase capacity of system for completely avoiding the crosstalk between the decrypted images. Each encrypted target image is separately encoded into a POF by using the MGSA which is with constraining the encrypted target image. Each created POF is then added to a prescribed fixed POF composed of a proposed MGSA-based phase encoding algorithm. Not only the wavelength and multiple-position parameters in the FrT domain as keys to increase system security, the created POFs are also served mutually as the encryption keys to decrypt target image based on cascading two POFs scheme. Compared with prior methods [23,24], the main advantages of this proposed encryption system is that it does not need any transformative lenses and that makes it very efficient and easy to implement optically. Simulation results show that this proposed encryption system can successfully achieve the multiple-image encryption with multiple-position keys, which is more advantageous in security than previous work [24] for its decryption process with only two POFs keys to accomplish this task.
Infrared and multi-type images fusion algorithm based on contrast pyramid transform
Xu, Hua; Wang, Yan; Wu, Yujing; Qian, Yunsheng
2016-09-01
A fusion algorithm for infrared and multi-type images based on contrast pyramid transform (CPT) combined with Otsu method and morphology is proposed in this paper. Firstly, two sharpened images are combined to the first fused image based on information entropy weighted scheme. Afterwards, two enhanced images and the first fused one are decomposed into a series of images with different dimensions and spatial frequencies. To the low-frequency layer, the Otsu method is applied to calculate the optimal segmentation threshold of the first fused image, which is subsequently used to determine the pixel values in top layer fused image. With respect to the high-frequency layers, the top-bottom hats morphological transform is employed to each layer before maximum selection criterion. Finally, the series of decomposed images are reconstructed and then superposed with the enhanced image processed by morphological gradient operation as a second fusion to get the final fusion image. Infrared and visible images fusion, infrared and low-light-level (LLL) images fusion, infrared intensity and infrared polarization images fusion, and multi-focus images fusion are discussed in this paper. Both experimental results and objective metrics demonstrate the effectiveness and superiority of the proposed algorithm over the conventional ones used to compare.
Ding Lu; Weimin Jin
2011-01-01
A novel fully phase color image encryption/decryption scheme based on joint fractional Fourier transform correlator (JFRTC) and phase retrieval algorithm (PRA) is proposed. The security of the system is enhanced by the fractional order as a new added key. This method takes full advantage of the parallel processing features of the optical system and could optically realize single-channel color image encryption.The system and operation procedures are simplified. The simulation results of a color image indicate that the new method provides efficient solutions with a strong sense of security.%@@ A novel fully phase color image encryption/decryption scheme based on joint fractional Fourier transform correlator (JFRTC) and phase retrieval algorithm (PRA) is proposed. The security of the system is enhanced by the fractional order as a new added key. This method takes full advantage of the parallel processing features of the optical system and could optically realize single-channel color image encryption. The system and operation procedures are simplified. The simulation results of a color image indicate that the new method provides efficient solutions with a strong sense of security.
A Novel Short-Time Fourier Transform-Based Fall Detection Algorithm Using 3-Axis Accelerations
Isu Shin
2015-01-01
Full Text Available The short-time Fourier transform- (STFT- based algorithm was suggested to distinguish falls from various activities of daily living (ADLs. Forty male subjects volunteered in the experiments including three types of falls and four types of ADLs. An inertia sensor unit attached to the middle of two anterior superior iliac spines was used to measure the 3-axis accelerations at 100 Hz. The measured accelerations were transformed to signal vector magnitude values to be analyzed using STFT. The powers of low frequency components were extracted, and the fall detection was defined as whether the normalized power was less than the threshold (50% of the normal power. Most power was observed at the frequency band lower than 5 Hz in all activities, but the dramatic changes in the power were found only in falls. The specificity of 1–3 Hz frequency components was the best (100%, but the sensitivity was much smaller compared with 4 Hz component. The 4 Hz component showed the best fall detection with 96.9% sensitivity and 97.1% specificity. We believe that the suggested algorithm based on STFT would be useful in the fall detection and the classification from ADLs as well.
A Progressive Black Top Hat Transformation Algorithm for Estimating Valley Volumes from DEM Data
Luo, W.; Pingel, T.; Heo, J.; Howard, A. D.
2013-12-01
The amount of valley incision and valley volume are important parameters in geomorphology and hydrology research, because they are related to the amount erosion (and thus the volume of sediments) and the amount of water needed to create the valley. This is not only the case for terrestrial research but also for planetary research as such figuring out how much water was on Mars. With readily available digital elevation model (DEM) data, the Black Top Hat (BTH) transformation, an image processing technique for extracting dark features on a variable background, has been applied to DEM data to extract valley depth and estimate valley volume. However, previous studies typically use one single structuring element size for extracting the valley feature and one single threshold value for removing noise, resulting in some finer features such as tributaries not being extracted and underestimation of valley volume. Inspired by similar algorithms used in LiDAR data analysis to separate above ground features and bare earth topography, here we propose a progressive BTH (PBTH) transformation algorithm, where the structuring elements size is progressively increased to extract valleys of different orders. In addition, a slope based threshold was introduced to automatically adjust the threshold values for structuring elements with different sizes. Connectivity and shape parameters of the masked regions were used to keep the long linear valleys while removing other smaller non-connected regions. Preliminary application of the PBTH to Grand Canyon and two sites on Mars has produced promising results. More testing and fine-tuning is in progress. The ultimate goal of the project is to apply the algorithm to estimate the volume of valley networks on Mars and the volume of water needed to form the valleys we observe today and thus infer the nature of the hydrologic cycle on early Mars. The project is funded by NASA's Mars Data Analysis program.
A progressive black top hat transformation algorithm for estimating valley volumes on Mars
Luo, Wei; Pingel, Thomas; Heo, Joon; Howard, Alan; Jung, Jaehoon
2015-02-01
The depth of valley incision and valley volume are important parameters in understanding the geologic history of early Mars, because they are related to the amount sediments eroded and the quantity of water needed to create the valley networks (VNs). With readily available digital elevation model (DEM) data, the Black Top Hat (BTH) transformation, an image processing technique for extracting dark features on a variable background, has been applied to DEM data to extract valley depth and estimate valley volume. Previous studies typically use a single window size for extracting the valley features and a single threshold value for removing noise, resulting in finer features such as tributaries not being extracted and underestimation of valley volume. Inspired by similar algorithms used in LiDAR data analysis to remove above-ground features to obtain bare-earth topography, here we propose a progressive BTH (PBTH) transformation algorithm, where the window size is progressively increased to extract valleys of different orders. In addition, a slope factor is introduced so that the noise threshold can be automatically adjusted for windows with different sizes. Independently derived VN lines were used to select mask polygons that spatially overlap the VN lines. Volume is calculated as the sum of valley depth within the selected mask multiplied by cell area. Application of the PBTH to a simulated landform (for which the amount of erosion is known) achieved an overall relative accuracy of 96%, in comparison with only 78% for BTH. Application of PBTH to Ma'adim Vallies on Mars not only produced total volume estimates consistent with previous studies, but also revealed the detailed spatial distribution of valley depth. The highly automated PBTH algorithm shows great promise for estimating the volume of VN on Mars on global scale, which is important for understanding its early hydrologic cycle.
A hybrid algorithm for the rapid Fourier transform of extensive series of data
A. S Franco
1971-12-01
Full Text Available A technique is described for the rapid Fourier transform of large series of numbers. The technique takes advantage of the fact that most digital series are highly factorizable by the number 2, which permits the use of the F.F.T. algorithm. Using two magnetic tape units, or alternatively magnetic disk facilities, very large series can be transformed efficiently with only modest computer facilities. For the transformation of odd-valued series the Thomas Prime-Factor and Gentleman and Sande algorithms are treated in detail.Apresenta-se neste trabalho uma técnica de transformação rápida de Fourier aplicada a uma longa série de valores numéricos. A técnica tira partido do fato de que a grande maioria das séries digitalizadas é, em geral, suscetível de fatoração onde aparece frequentemente o fator 2, o que permite o emprego do algorítmo da transformação rápida de Fourier (F.F.T.. Com o emprego de duas fitas magnéticas ou discos, pode ser efetuada eficientemente a transformação de longas séries em computadores de modesta memória. O algorítmo de fatores primos de Thomas e o de Gentleman e Sande são, respectivamente, tratados em detalhe, na transformação de séries com numero ímpar de valores.
The Exact Euclidean Distance Transform: A New Algorithm for Universal Path Planning
Juan Carlos Elizondo-Leal
2013-06-01
Full Text Available The Path‐Planning problem is a basic issue in mobile robotics, in order to allow the robots to solve more complex tasks, for example, an exploration assignment in which the distance given by the planner is taken as a utility measure. Among the different proposed approaches, algorithms based on an exact cell decomposition of the environment are very popular. In this paper, we present a new algorithm for universal path planning in cell decomposition, using a raster scan method for computing the Exact Euclidean Distance Transform (EEDT for each cell in the map. Our algorithm computes, for every cell in the map, the point sequence to the goal. For each sequence, the sub‐goals are selected near to the vertices of the obstacles, reducing the total distance to the goal without post processing. At the end, we obtain a smooth path up to the goal without the need for post‐processing. The paths are computed by visibility verification among the cells, exploiting the processing performed in the neighbouring cells.
Efficient Algorithm and Architecture of Critical-Band Transform for Low-Power Speech Applications
Woon-Seng Gan
2007-01-01
Full Text Available An efficient algorithm and its corresponding VLSI architecture for the critical-band transform (CBT are developed to approximate the critical-band filtering of the human ear. The CBT consists of a constant-bandwidth transform in the lower frequency range and a Brown constant-Q transform (CQT in the higher frequency range. The corresponding VLSI architecture is proposed to achieve significant power efficiency by reducing the computational complexity, using pipeline and parallel processing, and applying the supply voltage scaling technique. A 21-band Bark scale CBT processor with a sampling rate of 16 kHz is designed and simulated. Simulation results verify its suitability for performing short-time spectral analysis on speech. It has a better fitting on the human ear critical-band analysis, significantly fewer computations, and therefore is more energy-efficient than other methods. With a 0.35 μm CMOS technology, it calculates a 160-point speech in 4.99 milliseconds at 234 kHz. The power dissipation is 15.6 μW at 1.1 V. It achieves 82.1% power reduction as compared to a benchmark 256-point FFT processor.
Saddaf Rubab
2015-01-01
Full Text Available Steganography is a means to hide the existence of information exchange. Using this technique the sender embeds the secret information in some other media. This is done by replacing useless data in ordinary computer files with some other secret information. The secret information could be simple text, encoded text or images. The media used as the embedding plane could be an image, audio, video or text files. Using steganography ensures that no one apart from the sender and the receiver knows about the existence of the message. In this paper, a steganography method based on transforms used i.e. Wavelet and Contourlet. Devised algorithm was used against each transform. Blowfish Encryption method is also embedded to double the security impact. The major advantage of applying transforms is that the image quality is not degraded even if the number of embedded characters is increased. The proposed system operates well in most of the test cases. The average payload capacity is also considerably high.
Efficient Algorithm and Architecture of Critical-Band Transform for Low-Power Speech Applications
Gan Woon-Seng
2007-01-01
Full Text Available An efficient algorithm and its corresponding VLSI architecture for the critical-band transform (CBT are developed to approximate the critical-band filtering of the human ear. The CBT consists of a constant-bandwidth transform in the lower frequency range and a Brown constant- transform (CQT in the higher frequency range. The corresponding VLSI architecture is proposed to achieve significant power efficiency by reducing the computational complexity, using pipeline and parallel processing, and applying the supply voltage scaling technique. A 21-band Bark scale CBT processor with a sampling rate of 16 kHz is designed and simulated. Simulation results verify its suitability for performing short-time spectral analysis on speech. It has a better fitting on the human ear critical-band analysis, significantly fewer computations, and therefore is more energy-efficient than other methods. With a 0.35 m CMOS technology, it calculates a 160-point speech in 4.99 milliseconds at 234 kHz. The power dissipation is 15.6 W at 1.1 V. It achieves 82.1 power reduction as compared to a benchmark 256-point FFT processor.
Eldin, A.A. Hossam; Refaey, M.A. [Electrical Engineering Department, Alexandria University, Alexandria (Egypt)
2011-01-15
This paper proposes a novel methodology for transformer differential protection, based on wave shape recognition of the discriminating criterion extracted of the instantaneous differential currents. Discrete wavelet transform has been applied to the differential currents due to internal fault and inrush currents. The diagnosis criterion is based on median absolute deviation (MAD) of wavelet coefficients over a specified frequency band. The proposed algorithm is examined using various simulated inrush and internal fault current cases on a power transformer that has been modeled using electromagnetic transients program EMTDC software. Results of evaluation study show that, proposed wavelet based differential protection scheme can discriminate internal faults from inrush currents. (author)
M. De la Sen
2009-01-01
are given to define pointwisely the causal and anticausal Toeplitz and Hankel operators from the set of switching time instants generated from the switching function. The case of the auxiliary unforced system defined by the matrix of undelayed dynamics being dichotomic (i.e., it has no eigenvalue on the complex imaginary axis is considered in detail. Stability conditions as well as dual instability ones are discussed for this case which guarantee that the whole system is either stable, or unstable but no configuration of the switched system has eigenvalues within some vertical strip including the imaginary axis. It is proved that if the system is causal and uniformly controllable and observable, then it is globally asymptotically Lyapunov stable independent of the delays, that is, for any possibly values of such delays, provided that a minimum residence time in-between consecutive switches is kept or if all the set of matrices describing the auxiliary unforced delay—free system parameterizations commute pairwise.
Hankel Determinant and Orthogonal Polynomials for a Gaussian Weight with a Discontinuity at the Edge
Bogatskiy, A.; Claeys, T.; Its, A.
2016-10-01
We compute asymptotics for Hankel determinants and orthogonal polynomials with respect to a discontinuous Gaussian weight, in a critical regime where the discontinuity is close to the edge of the associated equilibrium measure support. Their behavior is described in terms of the Ablowitz-Segur family of solutions to the Painlevé II equation. Our results complement the ones in [33]. As consequences of our results, we conjecture asymptotics for an Airy kernel Fredholm determinant and total integral identities for Painlevé II transcendents, and we also prove a new result on the poles of the Ablowitz-Segur solutions to the Painlevé II equation. We also highlight applications of our results in random matrix theory.
Shin'ya Nakano
2014-05-01
Full Text Available A hybrid algorithm that combines the ensemble transform Kalman filter (ETKF and the importance sampling approach is proposed. Since the ETKF assumes a linear Gaussian observation model, the estimate obtained by the ETKF can be biased in cases with nonlinear or non-Gaussian observations. The particle filter (PF is based on the importance sampling technique, and is applicable to problems with nonlinear or non-Gaussian observations. However, the PF usually requires an unrealistically large sample size in order to achieve a good estimation, and thus it is computationally prohibitive. In the proposed hybrid algorithm, we obtain a proposal distribution similar to the posterior distribution by using the ETKF. A large number of samples are then drawn from the proposal distribution, and these samples are weighted to approximate the posterior distribution according to the importance sampling principle. Since the importance sampling provides an estimate of the probability density function (PDF without assuming linearity or Gaussianity, we can resolve the bias due to the nonlinear or non-Gaussian observations. Finally, in the next forecast step, we reduce the sample size to achieve computational efficiency based on the Gaussian assumption, while we use a relatively large number of samples in the importance sampling in order to consider the non-Gaussian features of the posterior PDF. The use of the ETKF is also beneficial in terms of the computational simplicity of generating a number of random samples from the proposal distribution and in weighting each of the samples. The proposed algorithm is not necessarily effective in case that the ensemble is located distant from the true state. However, monitoring the effective sample size and tuning the factor for covariance inflation could resolve this problem. In this paper, the proposed hybrid algorithm is introduced and its performance is evaluated through experiments with non-Gaussian observations.
Multi-focus image fusion algorithm based on adaptive PCNN and wavelet transform
Wu, Zhi-guo; Wang, Ming-jia; Han, Guang-liang
2011-08-01
Being an efficient method of information fusion, image fusion has been used in many fields such as machine vision, medical diagnosis, military applications and remote sensing. In this paper, Pulse Coupled Neural Network (PCNN) is introduced in this research field for its interesting properties in image processing, including segmentation, target recognition et al. and a novel algorithm based on PCNN and Wavelet Transform for Multi-focus image fusion is proposed. First, the two original images are decomposed by wavelet transform. Then, based on the PCNN, a fusion rule in the Wavelet domain is given. This algorithm uses the wavelet coefficient in each frequency domain as the linking strength, so that its value can be chosen adaptively. Wavelet coefficients map to the range of image gray-scale. The output threshold function attenuates to minimum gray over time. Then all pixels of image get the ignition. So, the output of PCNN in each iteration time is ignition wavelet coefficients of threshold strength in different time. At this moment, the sequences of ignition of wavelet coefficients represent ignition timing of each neuron. The ignition timing of PCNN in each neuron is mapped to corresponding image gray-scale range, which is a picture of ignition timing mapping. Then it can judge the targets in the neuron are obvious features or not obvious. The fusion coefficients are decided by the compare-selection operator with the firing time gradient maps and the fusion image is reconstructed by wavelet inverse transform. Furthermore, by this algorithm, the threshold adjusting constant is estimated by appointed iteration number. Furthermore, In order to sufficient reflect order of the firing time, the threshold adjusting constant αΘ is estimated by appointed iteration number. So after the iteration achieved, each of the wavelet coefficient is activated. In order to verify the effectiveness of proposed rules, the experiments upon Multi-focus image are done. Moreover
Program for the analysis of time series. [by means of fast Fourier transform algorithm
Brown, T. J.; Brown, C. G.; Hardin, J. C.
1974-01-01
A digital computer program for the Fourier analysis of discrete time data is described. The program was designed to handle multiple channels of digitized data on general purpose computer systems. It is written, primarily, in a version of FORTRAN 2 currently in use on CDC 6000 series computers. Some small portions are written in CDC COMPASS, an assembler level code. However, functional descriptions of these portions are provided so that the program may be adapted for use on any facility possessing a FORTRAN compiler and random-access capability. Properly formatted digital data are windowed and analyzed by means of a fast Fourier transform algorithm to generate the following functions: (1) auto and/or cross power spectra, (2) autocorrelations and/or cross correlations, (3) Fourier coefficients, (4) coherence functions, (5) transfer functions, and (6) histograms.
Bang, Jeongho; Yoo, Seokwon
2014-12-01
We propose a genetic-algorithm-based method to find the unitary transformations for any desired quantum computation. We formulate a simple genetic algorithm by introducing the "genetic parameter vector" of the unitary transformations to be found. In the genetic algorithm process, all components of the genetic parameter vectors are supposed to evolve to the solution parameters of the unitary transformations. We apply our method to find the optimal unitary transformations and to generalize the corresponding quantum algorithms for a realistic problem, the one-bit oracle decision problem, or the often-called Deutsch problem. By numerical simulations, we can faithfully find the appropriate unitary transformations to solve the problem by using our method. We analyze the quantum algorithms identified by the found unitary transformations and generalize the variant models of the original Deutsch's algorithm.
Bang, Jeongho [Seoul National University, Seoul (Korea, Republic of); Hanyang University, Seoul (Korea, Republic of); Yoo, Seokwon [Hanyang University, Seoul (Korea, Republic of)
2014-12-15
We propose a genetic-algorithm-based method to find the unitary transformations for any desired quantum computation. We formulate a simple genetic algorithm by introducing the 'genetic parameter vector' of the unitary transformations to be found. In the genetic algorithm process, all components of the genetic parameter vectors are supposed to evolve to the solution parameters of the unitary transformations. We apply our method to find the optimal unitary transformations and to generalize the corresponding quantum algorithms for a realistic problem, the one-bit oracle decision problem, or the often-called Deutsch problem. By numerical simulations, we can faithfully find the appropriate unitary transformations to solve the problem by using our method. We analyze the quantum algorithms identified by the found unitary transformations and generalize the variant models of the original Deutsch's algorithm.
BMW a ROSAT-HRI source catalogue obtained with a wavelet transform detection algorithm
Panzera, M R; Covino, S; Guzzo, L; Israel, G L; Lazzati, D; Mignani, R P; Moretti, A; Tagliaferri, G
2001-01-01
In collaboration with the Observatories of Palermo and Rome and the SAX-SDC we are constructing a multi-site interactive archive system featuring specific analysis tools. In this context we developed a detection algorithm based on the Wavelet Transform (WT) and performed a systematic analysis of all ROSAT-HRI public data (~3100 observations +1000 to come). The WT is specifically suited to detect and characterize extended sources while properly detecting point sources in very crowded fields. Moreover, the good angular resolution of HRI images allows the source extension and position to be accurately determined. This effort has produced the BMW (Brera Multiscale Wavelet) catalogue, with more than 19,000 sources detected at the ~4.2sigma level. For each source detection we have information on the position, X-ray flux and extension. This allows for instance to select complete samples of extended X-ray sources such as candidate clusters of galaxies or SNR's. Details about the detection algorithm and the catalogue ...
A novel polar format algorithm for SAR images utilizing post azimuth transform interpolation.
Holzrichter, Michael Warren; Martin, Grant D.; Doerry, Armin Walter
2005-09-01
SAR phase history data represents a polar array in the Fourier space of a scene being imaged. Polar Format processing is about reformatting the collected SAR data to a Cartesian data location array for efficient processing and image formation. In a real-time system, this reformatting or ''re-gridding'' operation is the most processing intensive, consuming the majority of the processing time; it also is a source of error in the final image. Therefore, any effort to reduce processing time while not degrading image quality is valued. What is proposed in this document is a new way of implementing real-time polar-format processing through a variation on the traditional interpolation/2-D Fast Fourier Transform (FFT) algorithm. The proposed change is based upon the frequency scaling property of the Fourier Transform, which allows a post azimuth FFT interpolation. A post azimuth processing interpolation provides overall benefits to image quality and potentially more efficient implementation of the polar format image formation process.
Algorithm, applications and evaluation for protein comparison by Ramanujan Fourier transform.
Zhao, Jian; Wang, Jiasong; Hua, Wei; Ouyang, Pingkai
2015-12-01
The amino acid sequence of a protein determines its chemical properties, chain conformation and biological functions. Protein sequence comparison is of great importance to identify similarities of protein structures and infer their functions. Many properties of a protein correspond to the low-frequency signals within the sequence. Low frequency modes in protein sequences are linked to the secondary structures, membrane protein types, and sub-cellular localizations of the proteins. In this paper, we present Ramanujan Fourier transform (RFT) with a fast algorithm to analyze the low-frequency signals of protein sequences. The RFT method is applied to similarity analysis of protein sequences with the Resonant Recognition Model (RRM). The results show that the proposed fast RFT method on protein comparison is more efficient than commonly used discrete Fourier transform (DFT). RFT can detect common frequencies as significant feature for specific protein families, and the RFT spectrum heat-map of protein sequences demonstrates the information conservation in the sequence comparison. The proposed method offers a new tool for pattern recognition, feature extraction and structural analysis on protein sequences.
An Effective Privacy-Preserving Algorithm Based on Logistic Map and Rubik’s Cube Transformation
Wenbin Yao
2014-01-01
Full Text Available Security and privacy issues present a strong barrier for users to adapt to cloud storage systems. In this paper, a new algorithm for data splitting called EPPA is presented to strengthen the confidentiality of data by two-phase process. In EPPA, data object is organized to be several Rubik’s cubes executed for several rounds transformation at the first phase. In every round, chaotic logistic maps generate pseudorandom sequences to cover the plaintext by executing Exclusive-OR operation to form the cipher. Then logistic map is used to create rotation policies to scramble data information based on Rubik’s cube transformation. At the second phase, all cubes are unfolded and combined together as a cross-shaped cube, which will be partitioned into a few data fragments to guarantee that every fragment does not contain continuous bytes. These fragments are stored on randomly chosen servers within cloud environment. Analyses and experiments show that this approach is efficient and useable for the confidentiality of user data in cloud storage system.
A.V. Gusynin
2005-02-01
Full Text Available The approach to simulation of flight dynamics and numerically-analytical method of airship control algorithms are offered. It’s based on differential transformations of initial mathematical model of airship motion. The given approach allows for elimination of viewing time function for their differential spectra in the image field. It gives the possibility to reduce a problem of closed algorithm synthesis of vehicle control to the solution of non-linear equation system concerning control variable.
Vadillo, Miguel A; Street, Chris N H; Beesley, Tom; Shanks, David R
2015-12-01
Poor calibration and inaccurate drift correction can pose severe problems for eye-tracking experiments requiring high levels of accuracy and precision. We describe an algorithm for the offline correction of eye-tracking data. The algorithm conducts a linear transformation of the coordinates of fixations that minimizes the distance between each fixation and its closest stimulus. A simple implementation in MATLAB is also presented. We explore the performance of the correction algorithm under several conditions using simulated and real data, and show that it is particularly likely to improve data quality when many fixations are included in the fitting process.
Sainath, Kamalesh; Donderici, Burkay
2013-01-01
We propose the complex-plane generalization of a powerful algebraic sequence acceleration algorithm, the Method of Weighted Averages (MWA), to guarantee \\emph{exponential-cum-algebraic} convergence of Fourier and Fourier-Hankel (F-H) integral transforms. This "complex-plane" MWA, effected via a linear-path detour in the complex plane, results in rapid, absolute convergence of field/potential solutions in multi-layered environments \\emph{regardless} of the source-observer geometry and anisotropy/loss of the media present. In this work, we first introduce a new integration path used to evaluate the field contribution arising from the radiation spectra. Subsequently, we (1) exhibit the foundational relations behind the complex-plane extension to a general Levin-type sequence convergence accelerator, (2) specialize this analysis to one member of the Levin transform family (the MWA), (3) address and circumvent restrictions, arising for two-dimensional integrals associated with wave dynamics problems, through minim...
Yang, Xue; Li, Xue-You; Li, Jia-Guo; Ma, Jun; Zhang, Li; Yang, Jan; Du, Quan-Ye
2014-02-01
Fast Fourier transforms (FFT) is a basic approach to remote sensing image processing. With the improvement of capacity of remote sensing image capture with the features of hyperspectrum, high spatial resolution and high temporal resolution, how to use FFT technology to efficiently process huge remote sensing image becomes the critical step and research hot spot of current image processing technology. FFT algorithm, one of the basic algorithms of image processing, can be used for stripe noise removal, image compression, image registration, etc. in processing remote sensing image. CUFFT function library is the FFT algorithm library based on CPU and FFTW. FFTW is a FFT algorithm developed based on CPU in PC platform, and is currently the fastest CPU based FFT algorithm function library. However there is a common problem that once the available memory or memory is less than the capacity of image, there will be out of memory or memory overflow when using the above two methods to realize image FFT arithmetic. To address this problem, a CPU and partitioning technology based Huge Remote Fast Fourier Transform (HRFFT) algorithm is proposed in this paper. By improving the FFT algorithm in CUFFT function library, the problem of out of memory and memory overflow is solved. Moreover, this method is proved rational by experiment combined with the CCD image of HJ-1A satellite. When applied to practical image processing, it improves effect of the image processing, speeds up the processing, which saves the time of computation and achieves sound result.
Mohamed, M. A.; Li, Hongzuo
2013-09-01
In this paper we follow the concept of the track before detect (TBD) category in order to perform a simple, fast and adaptive detection and tracking processes of dim pixel size moving targets in IR images sequence. We present two new algorithms based on an image frames transformation, the first algorithm is a recursive algorithm to measure the image background Baseline which help in assigning an adaptive threshold, while the second is an adaptive recursive statistical spatio-temporal algorithm for detecting and tracking the target. The results of applying the proposed algorithms on a set of frames having a simple single pixel target performing a linear motion shows a high efficiency and validity in the detecting of the motion, and the measurement of the background baseline.
OAM mode of the Hankel-Bessel vortex beam in weak to strong turbulent link of marine-atmosphere
Li, Ye; Zhang, Yixin
2017-04-01
We study the turbulent effects of maritime atmosphere on the propagation of the orbital angular momentum (OAM) modes of a vortex beam. Based on the modified Rytov approximation, we model the effective marine-atmospheric spectrum and the normalized energy weight of the vortex modes of Hankel-Bessel beams in a paraxial marine turbulent channel. Our results show that the intensity of the signal vortex modes of Hankel-Bessel beams in a non-turbulence channel increases with increasing the quantum number of the OAM of vortex modes from one to higher. We can utilize OAM eigenstates of the Hankel-Bessel vortex beam to increase the channel capacity in optical communication of the remote link. The normalized energy weight of signal OAM modes increases and that of crosstalk OAM modes decreases from the worst to the best turbulent maritime climate. The normalized energy weight of signal OAM modes reduces with the increasing of the turbulent outer scale from 0.1 \\text{m} to 0.5 \\text{m} and the receiving diameter, but it increases with increasing the turbulent outer scale when the outer scale is greater than 0.5 \\text{m} . The effects of the inner scale on the normalized energy weight of OAM modes can be ignored. We can mitigate the effects of turbulence by the choice of the longer wavelength and smaller receiver aperture.
Zhu, Yu; Liu, Xiaojun; Gao, Jie; Zhang, Yixin; Zhao, Fengsheng
2014-04-07
We develop a novel model of the probability density of the orbital angular momentum (OAM) modes for Hankel-Bessel beams in paraxial turbulence channel based on the Rytov approximation. The results show that there are multi-peaks of the mode probability density along the radial direction. The peak position of the mode probability density moves to beam center with the increasing of non-Kolmogorov turbulence-parameters and the generalized refractive-index structure parameters and with the decreasing of OAM quantum number, propagation distance and wavelength of the beams. Additionally, larger OAM quantum number and smaller non-Kolmogorov turbulence-parameter can be selected in order to obtain larger mode probability density. The probability density of the OAM mode crosstalk is increasing with the decreasing of the quantum number deviation and the wavelength. Because of the focusing properties of Hankel-Bessel beams in turbulence channel, compared with the Laguerre-Gaussian beams, Hankel-Bessel beams are a good light source for weakening turbulence spreading of the beams and mitigating the effects of turbulence on the probability density of the OAM mode.
Wu Yirong; Cao Fang; Hong Wen
2007-01-01
In this paper, the IHSL transform and the Fuzzy C-Means (FCM) segmentation algorithm are combined together to perform the unsupervised classification for fully polarimetric Synthetic Aperture Rader (SAR) data. We apply the IHSL colour transform to H/α/SPAN space to obtain a new space (RGB colour space) which has a uniform distinguishability among inner parameters and contains the whole polarimetric information in H/α/SPAN. Then the FCM algorithm is applied to this RGB space to finish the classification procedure. The main advantages of this method are that the parameters in the color space have similar interclass distinguishability, thus it can achieve a high performance in the pixel based segmentation algorithm, and since we can treat the parameters in the same way, the segmentation procedure can be simplified. The experiments show that it can provide an improved classification result compared with the method which uses the H/α/SPAN space directly during the segmentation procedure.
Yan Sun
2017-06-01
Full Text Available This paper puts forward a new color multi-focus image fusion algorithm based on fuzzy theory and dual-tree complex wavelet transform for the purpose of removing uncertainty when choosing sub-band coefficients in the smooth regions. Luminance component is the weighted average of the three color channels in the IHS color space and it is not sensitive to noise. According to the characteristics, luminance component was chosen as the measurement to calculate the focus degree. After separating the luminance component and spectrum component, Fisher classification and fuzzy theory were chosen as the fusion rules to conduct the choice of the coefficients after the dual-tree complex wavelet transform. So fusion color image could keep the natural color information as much as possible. This method could solve the problem of color distortion in the traditional algorithms. According to the simulation results, the proposed algorithm obtained better visual effects and objective quantitative indicators.
Liu, Hua-Long; Liu, Hua-Dong
2014-10-01
Partial discharge (PD) in power transformers is one of the prime reasons resulting in insulation degradation and power faults. Hence, it is of great importance to study the techniques of the detection and localization of PD in theory and practice. The detection and localization of PD employing acoustic emission (AE) techniques, as a kind of non-destructive testing, plus due to the advantages of powerful capability of locating and high precision, have been paid more and more attention. The localization algorithm is the key factor to decide the localization accuracy in AE localization of PD. Many kinds of localization algorithms exist for the PD source localization adopting AE techniques including intelligent and non-intelligent algorithms. However, the existed algorithms possess some defects such as the premature convergence phenomenon, poor local optimization ability and unsuitability for the field applications. To overcome the poor local optimization ability and easily caused premature convergence phenomenon of the fundamental genetic algorithm (GA), a new kind of improved GA is proposed, namely the sequence quadratic programming-genetic algorithm (SQP-GA). For the hybrid optimization algorithm, SQP-GA, the sequence quadratic programming (SQP) algorithm which is used as a basic operator is integrated into the fundamental GA, so the local searching ability of the fundamental GA is improved effectively and the premature convergence phenomenon is overcome. Experimental results of the numerical simulations of benchmark functions show that the hybrid optimization algorithm, SQP-GA, is better than the fundamental GA in the convergence speed and optimization precision, and the proposed algorithm in this paper has outstanding optimization effect. At the same time, the presented SQP-GA in the paper is applied to solve the ultrasonic localization problem of PD in transformers, then the ultrasonic localization method of PD in transformers based on the SQP-GA is proposed. And
Abhijeet Ravankar
2016-05-01
Full Text Available Line detection is an important problem in computer vision, graphics and autonomous robot navigation. Lines detected using a laser range sensor (LRS mounted on a robot can be used as features to build a map of the environment, and later to localize the robot in the map, in a process known as Simultaneous Localization and Mapping (SLAM. We propose an efficient algorithm for line detection from LRS data using a novel hopping-points Singular Value Decomposition (SVD and Hough transform-based algorithm, in which SVD is applied to intermittent LRS points to accelerate the algorithm. A reverse-hop mechanism ensures that the end points of the line segments are accurately extracted. Line segments extracted from the proposed algorithm are used to form a map and, subsequently, LRS data points are matched with the line segments to localize the robot. The proposed algorithm eliminates the drawbacks of point-based matching algorithms like the Iterative Closest Points (ICP algorithm, the performance of which degrades with an increasing number of points. We tested the proposed algorithm for mapping and localization in both simulated and real environments, and found it to detect lines accurately and build maps with good self-localization.
Abhijeet Ravankar
2016-05-01
Full Text Available Line detection is an important problem in computer vision, graphics and autonomous robot navigation. Lines detected using a laser range sensor (LRS mounted on a robot can be used as features to build a map of the environment, and later to localize the robot in the map, in a process known as Simultaneous Localization and Mapping (SLAM. We propose an efficient algorithm for line detection from LRS data using a novel hopping-points Singular Value Decomposition (SVD and Hough transform-based algorithm, in which SVD is applied to intermittent LRS points to accelerate the algorithm. A reverse-hop mechanism ensures that the end points of the line segments are accurately extracted. Line segments extracted from the proposed algorithm are used to form a map and, subsequently, LRS data points are matched with the line segments to localize the robot. The proposed algorithm eliminates the drawbacks of point-based matching algorithms like the Iterative Closest Points (ICP algorithm, the performance of which degrades with an increasing number of points. We tested the proposed algorithm for mapping and localization in both simulated and real environments, and found it to detect lines accurately and build maps with good self-localization.
Ham, Woonchul; Song, Chulgyu
2017-05-01
In this paper, we propose a new three-dimensional stereo image reconstruction algorithm for a photoacoustic medical imaging system. We also introduce and discuss a new theoretical algorithm by using the physical concept of Radon transform. The main key concept of proposed theoretical algorithm is to evaluate the existence possibility of the acoustic source within a searching region by using the geometric distance between each sensor element of acoustic detector and the corresponding searching region denoted by grid. We derive the mathematical equation for the magnitude of the existence possibility which can be used for implementing a new proposed algorithm. We handle and derive mathematical equations of proposed algorithm for the one-dimensional sensing array case as well as two dimensional sensing array case too. A mathematical k-wave simulation data are used for comparing the image quality of the proposed algorithm with that of general conventional algorithm in which the FFT should be necessarily used. From the k-wave Matlab simulation results, we can prove the effectiveness of the proposed reconstruction algorithm.
A Fast Algorithm of Generalized Radon-Fourier Transform for Weak Maneuvering Target Detection
Weijie Xia
2016-01-01
Full Text Available The generalized Radon-Fourier transform (GRFT has been proposed to detect radar weak maneuvering targets by realizing coherent integration via jointly searching in motion parameter space. Two main drawbacks of GRFT are the heavy computational burden and the blind speed side lobes (BSSL which will cause serious false alarms. The BSSL learning-based particle swarm optimization (BPSO has been proposed before to reduce the computational burden of GRFT and solve the BSSL problem simultaneously. However, the BPSO suffers from an apparent loss in detection performance compared with GRFT. In this paper, a fast implementation algorithm of GRFT using the BSSL learning-based modified wind-driven optimization (BMWDO is proposed. In the BMWDO, the BSSL learning procedure is also used to deal with the BSSL phenomenon. Besides, the MWDO adjusts the coefficients in WDO with Levy distribution and uniform distribution, and it outperforms PSO in a noisy environment. Compared with BPSO, the proposed method can achieve better detection performance with a similar computational cost. Several numerical experiments are also provided to demonstrate the effectiveness of the proposed method.
Tien Hoang, Nguyen; Koike, Katsuaki
2016-06-01
Hyperspectral remote sensing is more effective than multispectral remote sensing in many application fields because of having hundreds of observation bands with high spectral resolution. However, hyperspectral remote sensing resources are limited both in temporal and spatial coverage. Therefore, simulation of hyperspectral imagery from multispectral imagery with a small number of bands must be one of innovative topics. Based on this background, we have recently developed a method, Pseudo-Hyperspectral Image Synthesis Algorithm (PHISA), to transform Landsat imagery into hyperspectral imagery using the correlation of reflectance at the corresponding bands between Landsat and EO-1 Hyperion data. This study extends PHISA to simulate pseudo-hyperspectral imagery from EO-1 ALI imagery. The pseudo-hyperspectral imagery has the same number of bands as that of high-quality Hyperion bands and the same swath width as ALI scene. The hyperspectral reflectance data simulated from the ALI data show stronger correlation with the original Hyperion data than the one simulated from Landsat data. This high correlation originates from the concurrent observation by the ALI and Hyperion sensors that are on-board the same satellite. The accuracy of simulation results are verified by a statistical analysis and a surface mineral mapping. With a combination of the advantages of both ALI and Hyperion image types, the pseudo-hyperspectral imagery is proved to be useful for detailed identification of minerals for the areas outside the Hyperion coverage.
Desai, Naeem M.; Lionheart, William R. B.
2016-11-01
We give an explicit plane-by-plane filtered back-projection reconstruction algorithm for the transverse ray transform of symmetric second rank tensor fields on Euclidean three-space, using data from rotation about three orthogonal axes. We show that in the general case two-axis data is insufficient, but we give an explicit reconstruction procedure for the potential case with two-axis data. We describe a numerical implementation of the three-axis algorithm and give reconstruction results for simulated data.
无
2001-01-01
Using the Rador transform and morphological image processing, an algorithm for ship's wake detection in the SAR (synthetic aperture radar) image is developed. Being manipulated in the Radon space to invert the gray-level and binary images, the linesr texture of ship wake in oceanic clutter can be well detected. It has been applied to the automatic detection of a moving ship from the SEASAT SAR image. The results show that this algorithm is well robust in a strong noisy background and is not very sensitive to the threshold parameter and the working window size.
Vlachynska, Alzbeta; Oplatkova, Zuzana Kominkova; Sramka, Martin
2017-07-01
The aim of the work is to determine the coordinate system of an eye and insert a polar-axis system into images captured by a slip lamp. The image of the eye with the polar axis helps a surgeon accurately implant toric intraocular lens in the required position/rotation during the cataract surgery. In this paper, two common algorithms for pupil detection are compared: the circle Hough transform and Daugman's algorithm. The procedures were tested and analysed on the anonymous data set of 128 eyes captured at Gemini eye clinic in 2015.
Padmavathi Kora
2017-06-01
Full Text Available Electrocardiogram (ECG, a non-invasive diagnostic technique, used for detecting cardiac arrhythmia. From last decade industry dealing with biomedical instrumentation and research, demanding an advancement in its ability to distinguish different cardiac arrhythmia. Atrial Fibrillation (AF is an irregular rhythm of the human heart. During AF, the atrial moments are quicker than the normal rate. As blood is not completely ejected out of atria, chances for the formation of blood clots in atrium. These abnormalities in the heart can be identified by the changes in the morphology of the ECG. The first step in the detection of AF is preprocessing of ECG, which removes noise using filters. Feature extraction is the next key process in this research. Recent feature extraction methods, such as Auto Regressive (AR modeling, Magnitude Squared Coherence (MSC and Wavelet Coherence (WTC using standard database (MIT-BIH, yielded a lot of features. Many of these features might be insignificant containing some redundant and non-discriminatory features that introduce computational burden and loss of performance. This paper presents fast Conjugate Symmetric Sequency Ordered Complex Hadamard Transform (CS-SCHT for extracting relevant features from the ECG signal. The sparse matrix factorization method is used for developing fast and efficient CS-SCHT algorithm and its computational performance is examined and compared to that of the HT and NCHT. The applications of the CS-SCHT in the ECG-based AF detection is also discussed. These fast CS-SCHT features are optimized using Hybrid Firefly and Particle Swarm Optimization (FFPSO to increase the performance of the classifier.
Optimization of Circular Ring Microstrip Antenna Using Genetic Algorithm
Sathi, V.; Ghobadi, Ch.; Nourinia, J.
2008-10-01
Circular ring microstrip antennas have several interesting properties that make it attractive in wireless applications. Although several analysis techniques such as cavity model, generalized transmission line model, Fourier-Hankel transform domain and the method of matched asymptotic expansion have been studied by researchers, there is no efficient design tool that has been incorporated with a suitable optimization algorithm. In this paper, the cavity model analysis along with the genetic optimization algorithm is presented for the design of circular ring microstrip antennas. The method studied here is based on the well-known cavity model and the optimization of the dimensions and feed point location of the circular ring antenna is performed via the genetic optimization algorithm, to achieve an acceptable antenna operation around a desired resonance frequency. The antennas designed by this efficient design procedure were realized experimentally, and the results are compared. In addition, these results are also compared to the results obtained by the commercial electromagnetic simulation tool, the FEM based software, HFSS by ANSOFT.
Efficient Algorithm for the Discrete Gabor Transform with a long fir window
Søndergaard, Peter Lempel
2010-01-01
The Discrete Gabor Transform (DGT) is the most commonly used signal transform for doing signal analysis and synthesis using a linear frequency scale. In this paper we present a new method for computing the DGT, which has the lowest known computational complexity when the transform has a high...
Jian Zhao,Na Zhang,Jian Jia,; Huanwei Wang
2015-01-01
Contraposing the need of the robust digital watermark for the copyright protection field, a new digital watermarking algo-rithm in the non-subsampled contourlet transform (NSCT) domain is proposed. The largest energy sub-band after NSCT is selected to embed watermark. The watermark is embedded into scale-invariant feature transform (SIFT) regions. During embedding, the initial region is divided into some cirque sub-regions with the same area, and each watermark bit is embedded into one sub-region. Extensive simulation results and comparisons show that the algo-rithm gets a good trade-off of invisibility, robustness and capacity, thus obtaining good quality of the image while being able to effec-tively resist common image processing, and geometric and combo attacks, and normalized similarity is almost al reached.
Integral transforms and their applications
Debnath, Lokenath
2014-01-01
Integral Transforms and Their Applications, Third Edition covers advanced mathematical methods for many applications in science and engineering. The book is suitable as a textbook for senior undergraduate and first-year graduate students and as a reference for professionals in mathematics, engineering, and applied sciences. It presents a systematic development of the underlying theory as well as a modern approach to Fourier, Laplace, Hankel, Mellin, Radon, Gabor, wavelet, and Z transforms and their applications. New to the Third Edition New material on the historical development of classical a
A Non-linear Scaling Algorithm Based on chirp-z Transform for Squint Mode FMCW-SAR
Yu Bin-bin
2012-03-01
Full Text Available A non-linear scaling chirp-z imaging algorithm for squint mode Frequency Modulated Continuous Wave Synthetic Aperture Radar (FMCW-SAR is presented to solve the problem of the focus accuracy decline. Based on the non-linear characteristics in range direction for the echo signal in Doppler domain, a non-linear modulated signal is introduced to perform a non-linear scaling based on chirp-z transform. Then the error due to range compression and range migration correction can be reduced, therefore the range resolution of radar image is improved. By using the imaging algorithm proposed, the imaging performances for point targets, compared with that from the original chirp-z algorithm, are demonstrated to be improved in range resolution and image contrast, and to be maintained the same in azimuth resolution.
Graph Transformation and Designing Parallel Sparse Matrix Algorithms beyond Data Dependence Analysis
H.X. Lin
2004-01-01
Full Text Available Algorithms are often parallelized based on data dependence analysis manually or by means of parallel compilers. Some vector/matrix computations such as the matrix-vector products with simple data dependence structures (data parallelism can be easily parallelized. For problems with more complicated data dependence structures, parallelization is less straightforward. The data dependence graph is a powerful means for designing and analyzing parallel algorithms. However, for sparse matrix computations, parallelization based on solely exploiting the existing parallelism in an algorithm does not always give satisfactory results. For example, the conventional Gaussian elimination algorithm for the solution of a tri-diagonal system is inherently sequential, so algorithms specially for parallel computation has to be designed. After briefly reviewing different parallelization approaches, a powerful graph formalism for designing parallel algorithms is introduced. This formalism will be discussed using a tri-diagonal system as an example. Its application to general matrix computations is also discussed. Its power in designing parallel algorithms beyond the ability of data dependence analysis is shown by means of a new algorithm called ACER (Alternating Cyclic Elimination and Reduction algorithm.
LACKS,S.A.
2003-10-09
Transformation, which alters the genetic makeup of an individual, is a concept that intrigues the human imagination. In Streptococcus pneumoniae such transformation was first demonstrated. Perhaps our fascination with genetics derived from our ancestors observing their own progeny, with its retention and assortment of parental traits, but such interest must have been accelerated after the dawn of agriculture. It was in pea plants that Gregor Mendel in the late 1800s examined inherited traits and found them to be determined by physical elements, or genes, passed from parents to progeny. In our day, the material basis of these genetic determinants was revealed to be DNA by the lowly bacteria, in particular, the pneumococcus. For this species, transformation by free DNA is a sexual process that enables cells to sport new combinations of genes and traits. Genetic transformation of the type found in S. pneumoniae occurs naturally in many species of bacteria (70), but, initially only a few other transformable species were found, namely, Haemophilus influenzae, Neisseria meningitides, Neisseria gonorrheae, and Bacillus subtilis (96). Natural transformation, which requires a set of genes evolved for the purpose, contrasts with artificial transformation, which is accomplished by shocking cells either electrically, as in electroporation, or by ionic and temperature shifts. Although such artificial treatments can introduce very small amounts of DNA into virtually any type of cell, the amounts introduced by natural transformation are a million-fold greater, and S. pneumoniae can take up as much as 10% of its cellular DNA content (40).
Peters, Terri
2011-01-01
Artiklen diskuterer ordet "transformation" med udgangspunkt i dels hvorledes ordet bruges i arkitektfaglig terminologi og dels med fokus på ordets potentielle indhold og egnethed i samme teminologi.......Artiklen diskuterer ordet "transformation" med udgangspunkt i dels hvorledes ordet bruges i arkitektfaglig terminologi og dels med fokus på ordets potentielle indhold og egnethed i samme teminologi....
Peters, Terri
2011-01-01
Artiklen diskuterer ordet "transformation" med udgangspunkt i dels hvorledes ordet bruges i arkitektfaglig terminologi og dels med fokus på ordets potentielle indhold og egnethed i samme teminologi.......Artiklen diskuterer ordet "transformation" med udgangspunkt i dels hvorledes ordet bruges i arkitektfaglig terminologi og dels med fokus på ordets potentielle indhold og egnethed i samme teminologi....
Baker, W.R.
1959-08-25
Transformers of a type adapted for use with extreme high power vacuum tubes where current requirements may be of the order of 2,000 to 200,000 amperes are described. The transformer casing has the form of a re-entrant section being extended through an opening in one end of the cylinder to form a coaxial terminal arrangement. A toroidal multi-turn primary winding is disposed within the casing in coaxial relationship therein. In a second embodiment, means are provided for forming the casing as a multi-turn secondary. The transformer is characterized by minimized resistance heating, minimized external magnetic flux, and an economical construction.
Liu Zhi-Ming; Liu Wen-qing; Gao Ming-Guang; Tong Jing-Jing; Zhang Wian-Shu; Xu Liang; Wei Xiuai
2008-01-01
Passive Fourier transform infrared (FTIR) remote sensing measurement of chemical gas cloud is a vital technology.It takes an important part in many fields for the detection of released gases.The principle of concentration measurement is based on the Beer-Lambert law.Unlike the active measurement,for the passive remote sensing,in most cases,the difference between the temperature of the gas cloud and the brightness temperature of the background is usually a few kelvins.The gas cloud emission is almost equal to the background emission,thereby the emission of the gas cloud cannot be ignored.The concentration retrieval algorithm is quite different from the active measurement.In this paper,the concentration retrieval algorithm for the passive FTIR remote measurement of gas cloud is presented in detail,which involves radiative transfer model,radiometric calibration,absorption coefficient calculation,et al.The background spectrum has a broad feature,which is a slowly varying function of frequency.In this paper,the background spectrum is fitted with a polynomial by using the Levenberg-Marquardt method which is a kind of nonlinear least squares fitting algorithm.No background spectra are required.Thus,this method allows mobile,real-time and fast measurements of gas clouds.
Design methodology for optimal hardware implementation of wavelet transform domain algorithms
Johnson-Bey, Charles; Mickens, Lisa P.
2005-05-01
The work presented in this paper lays the foundation for the development of an end-to-end system design methodology for implementing wavelet domain image/video processing algorithms in hardware using Xilinx field programmable gate arrays (FPGAs). With the integration of the Xilinx System Generator toolbox, this methodology will allow algorithm developers to design and implement their code using the familiar MATLAB/Simulink development environment. By using this methodology, algorithm developers will not be required to become proficient in the intricacies of hardware design, thus reducing the design cycle and time-to-market.
Pang Chao-Yang; Hu Ben-Qiong
2008-01-01
The discrete Fourier transform(DFT)is the base of modern signal processing.1-dimensional fast Fourier transform (1D FFT)and 2D FFT have time complexity O(N log N)and O(N2 log N)respectively.Since 1965,there has been no more essential breakthrough for the design of fast DFT algorithm.DFT has two properties.One property is that DFT is energy conservation transform.The other property is that many DFT coefficients are close to zero.The basic idea of this paper is that the generalized Grover's iteration can perform the computation of DFT which acts on the entangled states to search the big DFT coefficients until these big coefficients contain nearly all energy.One-dimensional quantum DFT(1D QDFT)and two-dimensional quantum DFT(2D QDFT)are presented in this paper.The quantum algorithm for convolution estimation is also presented in this paper.Compared with FFT,1D and 2D QDFT have time complexity O(√N)and O(N)respectively.QDFT and quantum convolution demonstrate that quantum computation to process classical signal is possible.
Algorithm comparison and benchmarking using a parallel spectra transform shallow water model
Worley, P.H. [Oak Ridge National Lab., TN (United States); Foster, I.T.; Toonen, B. [Argonne National Lab., IL (United States)
1995-04-01
In recent years, a number of computer vendors have produced supercomputers based on a massively parallel processing (MPP) architecture. These computers have been shown to be competitive in performance with conventional vector supercomputers for some applications. As spectral weather and climate models are heavy users of vector supercomputers, it is interesting to determine how these models perform on MPPS, and which MPPs are best suited to the execution of spectral models. The benchmarking of MPPs is complicated by the fact that different algorithms may be more efficient on different architectures. Hence, a comprehensive benchmarking effort must answer two related questions: which algorithm is most efficient on each computer and how do the most efficient algorithms compare on different computers. In general, these are difficult questions to answer because of the high cost associated with implementing and evaluating a range of different parallel algorithms on each MPP platform.
Carvajal-Gamez
2012-09-01
Full Text Available When color images are processed in different color model for implementing steganographic algorithms, is important to study the quality of the host and retrieved images, since it is typically used digital filters, visibly reaching deformed images. Using a steganographic algorithm, numerical calculations performed by the computer cause errors and alterations in the test images, so we apply a proposed scaling factor depending on the number of bits of the image to adjust these errors.
B.E. Carvajal-Gámez
2012-08-01
Full Text Available When color images are processed in different color model for implementing steganographic algorithms, is important to study the quality of the host and retrieved images, since it is typically used digital filters, visibly reaching deformed images. Using a steganographic algorithm, numerical calculations performed by the computer cause errors and alterations in the test images, so we apply a proposed scaling factor depending on the number of bits of the image to adjust these errors.
Byambaa Dorj
2016-01-01
Full Text Available The next promising key issue of the automobile development is a self-driving technique. One of the challenges for intelligent self-driving includes a lane-detecting and lane-keeping capability for advanced driver assistance systems. This paper introduces an efficient and lane detection method designed based on top view image transformation that converts an image from a front view to a top view space. After the top view image transformation, a Hough transformation technique is integrated by using a parabolic model of a curved lane in order to estimate a parametric model of the lane in the top view space. The parameters of the parabolic model are estimated by utilizing a least-square approach. The experimental results show that the newly proposed lane detection method with the top view transformation is very effective in estimating a sharp and curved lane leading to a precise self-driving capability.
Image denoising algorithm of refuge chamber by combining wavelet transform and bilateral filtering
Zhang Weipeng
2013-01-01
In order to preferably identify infrared image of refuge chamber,reduce image noises of refuge chamber and retain more image details,we propose the method of combining two-dimensional discrete wavelet transform and bilateral denoising.First,the wavelet transform is adopted to decompose the image of refuge chamber,of which low frequency component remains unchanged.Then,three high-frequency components are treated by bilateral filtering,and the image is reconstructed.The result shows that the combination of bilateral filtering and wavelet transform for image denoising can better retain the details which are included in the image,while providing better visual effect.This is superior to using either bilateral filtering or wavelet transform alone.It is useful for perfecting emergency refuge system of coal.
Shukla, K K
2013-01-01
Due to its inherent time-scale locality characteristics, the discrete wavelet transform (DWT) has received considerable attention in signal/image processing. Wavelet transforms have excellent energy compaction characteristics and can provide perfect reconstruction. The shifting (translation) and scaling (dilation) are unique to wavelets. Orthogonality of wavelets with respect to dilations leads to multigrid representation. As the computation of DWT involves filtering, an efficient filtering process is essential in DWT hardware implementation. In the multistage DWT, coefficients are calculated
Walde, Marie; Jost, Aurélie; Wicker, Kai; Heintzmann, Rainer
2017-01-01
Bessel illumination is an established method in optical imaging and manipulation to achieve an extended depth of field without compromising the lateral resolution. When broadband or multicolour imaging is required, wavelength-dependent changes in the radial profile of the Bessel illumination can complicate further image processing and analysis. We present a solution for engineering a multicolour Bessel beam that is easy to implement and promises to be particularly useful for broadband imaging applications. A phase-only spatial light modulator (SLM) in the image plane and an iterative Fourier Transformation algorithm (IFTA) are used to create an annular light distribution in the back focal plane of a lens. The 2D Fourier transformation of such a light ring yields a Bessel beam with a constant radial profile for different wavelength.
Janzing, D; Janzing, Dominik; Beth, Thomas
2001-01-01
Estimating the eigenvalues of a unitary transformation U by standard phase estimation requires the implementation of controlled-U-gates which are not available if U is only given as a black box. We show that a simple trick allows to measure eigenvalues of U\\otimes U^\\dagger even in this case. Running the algorithm several times allows therefore to estimate the autocorrelation function of the density of eigenstates of U. This can be applied to find periodicities in the energy spectrum of a quantum system with unknown Hamiltonian if it can be coupled to a quantum computer.
Improved algorithm for reducing blocking artifacts of Tetrolet transform%Tetrolet变换方块效应改善算法
张凌晓; 刘克成; 李财莲
2014-01-01
In order to reduce the blocking artifacts resulted from Ttetrolet transform algorithm, Tetrolet transform was improved and Cycle Spinning was employed to avoid the blocking artifacts in this paper. And thus the improved Tetrolet transform was introduced and performed for image denoising. Some numerical experiments show the effectiveness and superiority of our technique. Compared with typical Tetrolet transform, the denoised images by our method are smoother, and the blocking artifacts is improved to some extent and inhibition. At the same time it can preserve more significant information of original images, such as local features, including image edges and image details. In addition, the proposed method gives better performance in Peak Signal to Noise Ratio (PSNR) and improves the quality of subjective and objective of image. Experimental results show that the proposed algorithm is effective and feasible, and can perform better on most data sets.%针对Tetrolet变换算法对图像去噪后存在方块效应的缺陷，文中对Tetrolet变换算法进行了扩展和改进，并引入移位(Cycle Spinning)来有效消除Tetrolet变换算法中的方块效应。仿真结果表明，所提出的算法不仅能有效去除噪声，而且可得到更高的峰值信噪比，提高了图像的主客观质量。去噪后图像保留了原始图像的边缘和细节等局部特征，较为平滑，且方块效应得到了一定的改善和抑制，因而该算法是有效可行的。
2015-01-01
In this paper, a robust algorithm for fault diagnosis of power system equipment based on a failure-sensitive matrix (FSM) is presented. The FSM is a dynamic matrix structure updated by multiple measurements (online) and test results (offline) on the systems. The algorithm uses many different artificial intelligence and expert system methods for adaptively detecting the location of faults, emerging failures, and causes of failures. In this algorithm, all data obtained from the power transforme...
Penenko, Alexey; Penenko, Vladimir; Nuterman, Roman; Baklanov, Alexander; Mahura, Alexander
2015-11-01
Atmospheric chemistry dynamics is studied with convection-diffusion-reaction model. The numerical Data Assimilation algorithm presented is based on the additive-averaged splitting schemes. It carries out ''fine-grained'' variational data assimilation on the separate splitting stages with respect to spatial dimensions and processes i.e. the same measurement data is assimilated to different parts of the split model. This design has efficient implementation due to the direct data assimilation algorithms of the transport process along coordinate lines. Results of numerical experiments with chemical data assimilation algorithm of in situ concentration measurements on real data scenario have been presented. In order to construct the scenario, meteorological data has been taken from EnviroHIRLAM model output, initial conditions from MOZART model output and measurements from Airbase database.
New algorithms for processing images in the transform-compressed domain
Chang, Shih-Fu
1995-04-01
Future multimedia applications involving images and video will require technologies enabling users to manipulate image and video data as flexibly as traditional text and numerical data. However, vast amounts of image and video data mandate the use of image compression, which makes direct manipulation and editing of image data difficult. To explore the maximum synergistic relationships between image manipulation and compression, we extend our prior study of transform-domain image manipulation techniques to more complicated image operations such as rotation, shearing, and line-wise special effects. We propose to extract the individual image rows (columns) first and then apply the previously proposed transform-domain filtering and scaling techniques. The transform-domain rotation and line-wise operations can be accomplished by calculating the summation of products of nonzero transform coefficients and some precalculated special matrices. The overall computational complexity depends on the compression rate of the input images. For highly-compressed images, the transform-domain technique provides great potential for improving the computation speed.
We describe the development and evaluation of two new model algorithms for NOx chemistry in the R-LINE near-road dispersion model for traffic sources. With increased urbanization, there is increased mobility leading to higher amount of traffic related activity on a global scale. ...
We describe the development and evaluation of two new model algorithms for NOx chemistry in the R-LINE near-road dispersion model for traffic sources. With increased urbanization, there is increased mobility leading to higher amount of traffic related activity on a global scale. ...
A Compensation Algorithm Based on RSPWVD-Hough Transform for Doppler Expansion in Passive Radar
Guan Xin
2013-12-01
Full Text Available For passive radar, long integration time is used to achieve high processing gain to detect weak target. But range migration and Doppler expansion may occur for high-speed targets. Keystone transform can be used to rectify range migration introduced by radial-speed. But tangential-speed may still lead to Doppler expansion, which entails a loss of integration gain. In this paper, signal model is presented to analyze the reason for Doppler expansion. Then, a Doppler expansion compensation method is introduced based on RSPWVD-Hough transform for multi-target scenario. Simulation results show that the proposed method can compensate the energy loss caused by Doppler expansion for multi-target scene, and it achieves good performance. The proposed method is also effective for weak targets, which means it can improve the detection ability of weak target in passive radar systems.
Sharma, K. K.; Jain, Heena
2013-01-01
The security of digital data including images has attracted more attention recently, and many different image encryption methods have been proposed in the literature for this purpose. In this paper, a new image encryption method using wavelet packet decomposition and discrete linear canonical transform is proposed. The use of wavelet packet decomposition and DLCT increases the key size significantly making the encryption more robust. Simulation results of the proposed technique are also presented.
Intel Cilk Plus for Complex Parallel Algorithms: "Enormous Fast Fourier Transform" (EFFT) Library
Asai, Ryo; Vladimirov, Andrey
2014-01-01
In this paper we demonstrate the methodology for parallelizing the computation of large one-dimensional discrete fast Fourier transforms (DFFTs) on multi-core Intel Xeon processors. DFFTs based on the recursive Cooley-Tukey method have to control cache utilization, memory bandwidth and vector hardware usage, and at the same time scale across multiple threads or compute nodes. Our method builds on single-threaded Intel Math Kernel Library (MKL) implementation of DFFT, and uses the Intel Cilk P...
Wei, Xiuyan; Song, Xinyue; Dong, Dong; Keyhani, Nemat O; Yao, Lindan; Zang, Xiangyun; Dong, Lili; Gu, Zijian; Fu, Delai; Liu, Xingzhong; Qiu, Junzhi; Guan, Xiong
2016-07-01
The insect pathogenic fungus Aschersonia placenta is a highly effective pathogen of whiteflies and scale insects. However, few genetic tools are currently available for studying this organism. Here we report on the conditions for the production of transformable A. placenta protoplasts using an optimized protocol based on the response surface method (RSM). Critical parameters for protoplast production were modelled by using a Box-Behnken design (BBD) involving 3 levels of 3 variables that was subsequently tested to verify its ability to predict protoplast production (R(2) = 0.9465). The optimized conditions resulted in the highest yield of protoplasts ((4.41 ± 0.02) × 10(7) cells/mL of culture, mean ± SE) when fungal cells were treated with 26.1 mg/mL of lywallzyme for 4 h of digestion, and subsequently allowed to recover for 64.6 h in 0.7 mol/L NaCl-Tris buffer. The latter was used as an osmotic stabilizer. The yield of protoplasts was approximately 10-fold higher than that of the nonoptimized conditions. Generated protoplasts were transformed with vector PbarGPE containing the bar gene as the selection marker. Transformation efficiency was 300 colonies/(μg DNA·10(7) protoplasts), and integration of the vector DNA was confirmed by PCR. The results show that rational design strategies (RSM and BBD methods) are useful to increase the production of fungal protoplasts for a variety of downstream applications.
Khoje, Suchitra
2017-07-24
Images of four qualities of mangoes and guavas are evaluated for color and textural features to characterize and classify them, and to model the fruit appearance grading. The paper discusses three approaches to identify most discriminating texture features of both the fruits. In the first approach, fruit's color and texture features are selected using Mahalanobis distance. A total of 20 color features and 40 textural features are extracted for analysis. Using Mahalanobis distance and feature intercorrelation analyses, one best color feature (mean of a* [L*a*b* color space]) and two textural features (energy a*, contrast of H*) are selected as features for Guava while two best color features (R std, H std) and one textural features (energy b*) are selected as features for mangoes with the highest discriminate power. The second approach studies some common wavelet families for searching the best classification model for fruit quality grading. The wavelet features extracted from five basic mother wavelets (db, bior, rbior, Coif, Sym) are explored to characterize fruits texture appearance. In third approach, genetic algorithm is used to select only those color and wavelet texture features that are relevant to the separation of the class, from a large universe of features. The study shows that image color and texture features which were identified using a genetic algorithm can distinguish between various qualities classes of fruits. The experimental results showed that support vector machine classifier is elected for Guava grading with an accuracy of 97.61% and artificial neural network is elected from Mango grading with an accuracy of 95.65%. The proposed method is nondestructive fruit quality assessment method. The experimental results has proven that Genetic algorithm along with wavelet textures feature has potential to discriminate fruit quality. Finally, it can be concluded that discussed method is an accurate, reliable, and objective tool to determine fruit
RECURSIVE FILTERING RADON-AMBIGUITY TRANSFORM ALGORITHM FOR DETECTING MULTI-LFM SIGNALS
Li Yingxiang; Xiao Xianci
2003-01-01
In multi-LFM signal condition, Radon-Ambiguity Transform (RAT) of the strongLFM component has strong suppression effect on that of the weak LFM component. A methodnamed as Recursive Filtering RAT (RFRAT) Mgorithm is proposed for solving this problem. Byfully using of the Maximum Likelihood (ML) estimation value of the frequency modulation rategot by RAT. RFRAT can detect the noisy multi-LFM signals out step by step. The merit of thisnew method is validated by an illustrative example in low Signal-to-Noise-Ratio (SNR) condition.
A novel super-resolution image fusion algorithm based on improved PCNN and wavelet transform
Liu, Na; Gao, Kun; Song, Yajun; Ni, Guoqiang
2009-10-01
Super-resolution reconstruction technology is to explore new information between the under-sampling image series obtained from the same scene and to achieve the high-resolution picture through image fusion in sub-pixel level. The traditional super-resolution fusion methods for sub-sampling images need motion estimation and motion interpolation and construct multi-resolution pyramid to obtain high-resolution, yet the function of the human beings' visual features are ignored. In this paper, a novel resolution reconstruction for under-sampling images of static scene based on the human vision model is considered by introducing PCNN (Pulse Coupled Neural Network) model, which simplifies and improves the input model, internal behavior and control parameters selection. The proposed super-resolution image fusion algorithm based on PCNN-wavelet is aimed at the down-sampling image series in a static scene. And on the basis of keeping the original features, we introduce Relief Filter(RF) to the control and judge segment to overcome the effect of random factors(such as noise, etc) effectively to achieve the aim that highlighting interested object though the fusion. Numerical simulations show that the new algorithm has the better performance in retaining more details and keeping high resolution.
Wang, Xiaojun; Lai, Weidong
2011-08-01
In this paper, a combined method have been put forward for one ASTER detected image with the wavelet filter to attenuate the noise and the anisotropic diffusion PDE(Partial Differential Equation) for further recovering image contrast. The model is verified in different noising background, since the remote sensing image usually contains salt and pepper, Gaussian as well as speckle noise. Considered the features that noise existing in wavelet domain, the wavelet filter with Bayesian estimation threshold is applied for recovering image contrast from the blurring background. The proposed PDE are performing an anisotropic diffusion in the orthogonal direction, thus preserving the edges during further denoising process. Simulation indicates that the combined algorithm can more effectively recover the blurred image from speckle and Gauss noise background than the only wavelet denoising method, while the denoising effect is also distinct when the pepper-salt noise has low intensity. The combined algorithm proposed in this article can be integrated in remote sensing image analyzing to obtain higher accuracy for environmental interpretation and pattern recognition.
1984-04-01
CIR (3.2) *. where B(v) is a finite or infinite product of Blaschke factors, i.e. V-v* B(v) = TI B (v) where B lV ) = ( 3.3) i=l k Zk v~vk Furthermore...language, it is: f-t Given the sets {Ti1 with associated projections Pi =P1 i=l 1 T.iM4 1 find G such that GE n T.i=l I_ Gubin, Polyak and Raik 137] have...36. J.R. Fienup, "Phase retrieval algorithms: a comparison." Appl. Opt., 21, 2758-2769 (1982). 37. L. Gubin, B. Polyak , and E. Raik, "The method of
A Novel Scrambling Digital Image Watermark Algorithm Based on Double Transform Domains
Taiyue Wang
2015-01-01
Full Text Available Digital watermark technology is a very good method for protecting copyright. In this paper, in terms of requisition of imperceptibility and robustness of watermarking, the multidirectional, multiscale, and band-pass coefficient features of Curvelet transform are introduced and a novel image watermark scheme based on Curvelet and human visual system is proposed. Digital watermark information is embedded into the first 16 directions with larger energy in the fourth layer. Experimental results indicate that the proposed watermark scheme is feasible and simple. Simultaneously, the embedded watermark images just have tiny difference with the original images and the extracted watermark is accurate. Moreover, it is imperceptible and robust against various methods of signals processing such as cropping, noise adding, and rotating and altering.
Mohd Tahir Ismail
2016-06-01
Full Text Available The daily returns of four African countries' stock market indices for the period January 2, 2000, to December 31, 2014, were employed to compare the GARCH(1,1 model and a newly proposed Maximal Overlap Discreet Wavelet Transform (MODWT-GARCH(1,1 model. The results showed that although both models fit the returns data well, the forecast produced by the GARCH(1,1 model underestimates the observed returns whereas the newly proposed MODWT-GARCH(1,1 model generates an accurate forecast value of the observed returns. The results generally showed that the newly proposed MODWT-GARCH(1,1 model best fits returns series for these African countries. Hence the proposed MODWT-GARCH should be applied on other context to further verify its validity.
Wang, Kun; Li, Jinyang; Lu, Dan-Feng; Qi, Zhi-Mei
2016-07-08
In a recent report we demonstrated a miniature static Fourier transform spectrometer (FTS) that was implemented with a LiNbO3 (LN) waveguide electro-optic modulator (EOM) combined with the dispersion relation between its half-wave voltage and wavelength. The FTS was verified to be able to measure laser wavelength and for low-resolution spectroscopy. In this report, we successfully applied the resolution enhancement algorithm to the FTS, resulting in at least a three-fold increase in its spectral resolution without causing obvious distortion of the measured spectra. The algorithm method used is based on an autoregressive (AR) model, singular value decomposition (SVD), and forward-backward linear prediction (FBLP). The combination of these methods allows the FTS to remain a small size but to possess good spectral resolution, effectively mitigating the conflict between the small size and high resolution of the device. This study opens the way to development of high-resolution miniature FTS. © The Author(s) 2016.
Wei Yang
2016-12-01
Full Text Available Based on the terrain observation by progressive scans (TOPS mode, an efficient full-aperture image formation algorithm for focusing wide-swath spaceborne TOPS data is proposed. First, to overcome the Doppler frequency spectrum aliasing caused by azimuth antenna steering, the range-independent derotation operation is adopted, and the signal properties after derotation are derived in detail. Then, the azimuth deramp operation is performed to resolve image folding in azimuth. The traditional dermap function will introduce a time shift, resulting in appearance of ghost targets and azimuth resolution reduction at the scene edge, especially in the wide-swath coverage case. To avoid this, a novel solution is provided using a modified range-dependent deramp function combined with the chirp-z transform. Moreover, range scaling and azimuth scaling are performed to provide the same azimuth and range sampling interval for all sub-swaths, instead of the interpolation operation for the sub-swath image mosaic. Simulation results are provided to validate the proposed algorithm.
Jia, J H; Liu, Z; Chen, X; Xiao, X; Liu, B X
2015-10-02
Studying the network of protein-protein interactions (PPIs) will provide valuable insights into the inner workings of cells. It is vitally important to develop an automated, high-throughput tool that efficiently predicts protein-protein interactions. This study proposes a new model for PPI prediction based on the concept of chaos game representation and the wavelet transform, which means that a considerable amount of sequence-order effects can be incorporated into a set of discrete numbers. The advantage of using chaos game representation and the wavelet transform to formulate the protein sequence is that it can more effectively reflect its overall sequence-order characteristics than the conventional correlation factors. Using such a formulation frame to represent the protein sequences means that the random forest algorithm can be used to conduct the prediction. The results for a large-scale independent test dataset show that the proposed model can achieve an excellent performance with an accuracy value of about 0.86 and a geometry mean value of about 0.85. The model is therefore a useful supplementary tool for PPI predictions. The predictor used in this article is freely available at http://www.jci-bioinfo.cn/PPI.
Lu Liu
2015-01-01
Full Text Available Fractional-order time-delay system is thought to be a kind of oscillatory complex system which could not be controlled efficaciously so far because it does not have an analytical solution when using inverse Laplace transform. In this paper, a type of fractional-order controller based on numerical inverse Laplace transform algorithm INVLAP was proposed for the mentioned systems by searching for the optimal controller parameters with the objective function of ITAE index due to the verified nature that fractional-order controllers were the best means of controlling fractional-order systems. Simulations of step unit tracking and load-disturbance responses of the proposed fractional-order optimal PIλDμ controller (FOPID and corresponding conventional optimal PID (OPID controller have been done on three typical kinds of fractional time-delay system with different ratio between time delay (L and time constant (T and a complex high-order fractional time delay system to verify the availability of the presented control method.
基于Gabor变换的快速跟踪算法%Fast tracking algorithm based on Gabor transformation
徐天阳; 吴小俊
2016-01-01
In order to enhance the speed and accuracy of object tracking, a fast tracking algorithm based on Gabor trans-formation is proposed. According to the good simulation capability of Gabor transformation to human visual receptive field, the proposed algorithm extracts features via multi-scale and multi-orientation Gabor filters, and then realizes track-ing by utilizing image matching between target model and candidates. At the feature extracting stage, a multi-channel model is used to fuse Gabor features. And at the output stage, convolution property in spatial-frequency domain is exploited to realize fast posterior distribution computation. Experimental results indicate that the proposed algorithm has good prop-erties in accuracy and speed, and outperforms state-of-the-art methods.%为了增强目标跟踪的速度和精度，提出了一种基于Gabor变换的快速跟踪算法。根据Gabor变换对人类视觉感受野良好的模拟能力，用多尺度多方向的Gabor滤波器对目标图像进行特征抽取，以此建立目标的表观模型，而后利用图像匹配的方法得到相邻帧目标位置的后验概率分布从而实现跟踪。其中在特征抽取级利用线性多通道模型将不同尺度和方向的Gabor特征融合起来，在输出级利用时频的卷积特性以FFT实现相邻帧目标位置后验概率的快速计算，充分考虑了跟踪的速度和精度。实验结果表明，该算法选用的Gabor特征对目标有准确的描述能力，以此建立的表观模型鲁棒性强；同时跟踪过程简单快速，在精度和速度上与其他前沿的跟踪算法相较有优越性。
Erik Cuevas
2015-01-01
Full Text Available In this paper, a new method for robustly estimating multiple view relations from point correspondences is presented. The approach combines the popular random sampling consensus (RANSAC algorithm and the evolutionary method harmony search (HS. With this combination, the proposed method adopts a different sampling strategy than RANSAC to generate putative solutions. Under the new mechanism, at each iteration, new candidate solutions are built taking into account the quality of the models generated by previous candidate solutions, rather than purely random as it is the case of RANSAC. The rules for the generation of candidate solutions (samples are motivated by the improvisation process that occurs when a musician searches for a better state of harmony. As a result, the proposed approach can substantially reduce the number of iterations still preserving the robust capabilities of RANSAC. The method is generic and its use is illustrated by the estimation of homographies, considering synthetic and real images. Additionally, in order to demonstrate the performance of the proposed approach within a real engineering application, it is employed to solve the problem of position estimation in a humanoid robot. Experimental results validate the efficiency of the proposed method in terms of accuracy, speed, and robustness.
An algorithm to transform natural language into SQL queries for relational databases
Garima Singh
2016-09-01
Full Text Available Intelligent interface, to enhance efficient interactions between user and databases, is the need of the database applications. Databases must be intelligent enough to make the accessibility faster. However, not every user familiar with the Structured Query Language (SQL queries as they may not aware of structure of the database and they thus require to learn SQL. So, non-expert users need a system to interact with relational databases in their natural language such as English. For this, Database Management System (DBMS must have an ability to understand Natural Language (NL. In this research, an intelligent interface is developed using semantic matching technique which translates natural language query to SQL using set of production rules and data dictionary. The data dictionary consists of semantics sets for relations and attributes. A series of steps like lower case conversion, tokenization, speech tagging, database element and SQL element extraction is used to convert Natural Language Query (NLQ to SQL Query. The transformed query is executed and the results are obtained by the user. Intelligent Interface is the need of database applications to enhance efficient interaction between user and DBMS.
基于特征均值的SVD信号去噪算法%MEAN VALUE OF EIGENVALUE-BASED SVD SIGNAL DENOISING ALGORITHM
王益艳
2012-01-01
根据矩阵奇异值分解厚理,提出基于特征均值的信号去噪算法.该算法首先构造出加噪信号的Hankel矩阵,并对其进行SVD变换,再将小于全体特征值的均值的那些特征值置零,最后通过SVD反交换重建出去噪后的信号.通过与传统小波和FFT 信号去噪算法进行对比实验.结果表明,该方法具有较强的噪声鲁棒性,同时能更好地保留信号细节,但实现速度有所降低.%A signal denoising algorithm based on mean value of eigenvalue is proposed, which is according to the principle of matrix singular value decomposition. Firstly, this algorithm constructs a Hankel matrix with noised signal, and conducts SVD transformation on it; then it sets those eigenvalues to zero of which they are less than the mean value of all eigenvalues; finally it reconstructs the denoised signal through inverse SVD transformation. Experimental results of comparing the proposed method with traditional wavelet transform and FFT signal denois-ing method show that it has stronger noise robustness and can reserve signal details better, but its implementation speed is somewhat decreased.
Byung Eun Lee
2014-09-01
Full Text Available This paper proposes an algorithm for fault detection, faulted phase and winding identification of a three-winding power transformer based on the induced voltages in the electrical power system. The ratio of the induced voltages of the primary-secondary, primary-tertiary and secondary-tertiary windings is the same as the corresponding turns ratio during normal operating conditions, magnetic inrush, and over-excitation. It differs from the turns ratio during an internal fault. For a single phase and a three-phase power transformer with wye-connected windings, the induced voltages of each pair of windings are estimated. For a three-phase power transformer with delta-connected windings, the induced voltage differences are estimated to use the line currents, because the delta winding currents are practically unavailable. Six detectors are suggested for fault detection. An additional three detectors and a rule for faulted phase and winding identification are presented as well. The proposed algorithm can not only detect an internal fault, but also identify the faulted phase and winding of a three-winding power transformer. The various test results with Electromagnetic Transients Program (EMTP-generated data show that the proposed algorithm successfully discriminates internal faults from normal operating conditions including magnetic inrush and over-excitation. This paper concludes by implementing the algorithm into a prototype relay based on a digital signal processor.
Transform methods for solving partial differential equations
Duffy, Dean G
2004-01-01
Transform methods provide a bridge between the commonly used method of separation of variables and numerical techniques for solving linear partial differential equations. While in some ways similar to separation of variables, transform methods can be effective for a wider class of problems. Even when the inverse of the transform cannot be found analytically, numeric and asymptotic techniques now exist for their inversion, and because the problem retains some of its analytic aspect, one can gain greater physical insight than typically obtained from a purely numerical approach. Transform Methods for Solving Partial Differential Equations, Second Edition illustrates the use of Laplace, Fourier, and Hankel transforms to solve partial differential equations encountered in science and engineering. The author has expanded the second edition to provide a broader perspective on the applicability and use of transform methods and incorporated a number of significant refinements: New in the Second Edition: ·...
The Fourier Transform on Quantum Euclidean Space
Kevin Coulembier
2011-05-01
Full Text Available We study Fourier theory on quantum Euclidean space. A modified version of the general definition of the Fourier transform on a quantum space is used and its inverse is constructed. The Fourier transforms can be defined by their Bochner's relations and a new type of q-Hankel transforms using the first and second q-Bessel functions. The behavior of the Fourier transforms with respect to partial derivatives and multiplication with variables is studied. The Fourier transform acts between the two representation spaces for the harmonic oscillator on quantum Euclidean space. By using this property it is possible to define a Fourier transform on the entire Hilbert space of the harmonic oscillator, which is its own inverse and satisfies the Parseval theorem.
HU Bo; YUE Jian-hua; YANG Hai-yan
2009-01-01
For some time, whole space feature as a theoretical problem has been a puzzle in mining transient electromagnetic method (TEM). We have introduced a detailed method of calculating the transient response of a vertical magnetic bipolar source in a whole space plane layered medium in order to obtain whole space features. After designing a whole space plane layered medium model, equations were established based on boundary conditions in terms of electromagnetic vector potential. Expressions of electromag-netic fields were obtained by solving these equations. The expressions were computed by the Hankel transform after dispersion. The results in a frequency domain were changed into a time domain by using a multinomial cosine transform method. The expressions were correctly validated by comparing them with the analytical solution in half space. The half space and whole space results show that the whole space features are clear, suggesting that the theory of half space is not suitable for the whole space. Our algorithm supplied the technical instrument for studying the distributed features of whole space transient electromagnetic fields.
Tan, Cheng-Yang; /Fermilab
2011-02-01
A bootstrap algorithm for reconstructing the temporal signal from four of its fractional Fourier intensity spectra in the presence of noise is described. An optical arrangement is proposed which realises the bootstrap method for the measurement of ultrashort laser pulses. The measurement of short laser pulses which are less than 1 ps is an ongoing challenge in optical physics. One reason is that no oscilloscope exists today which can directly measure the time structure of these pulses and so it becomes necessary to invent other techniques which indirectly provide the necessary information for temporal pulse reconstruction. One method called FROG (frequency resolved optical gating) has been in use since 19911 and is one of the popular methods for recovering these types of short pulses. The idea behind FROG is the use of multiple time-correlated pulse measurements in the frequency domain for the reconstruction. Multiple data sets are required because only intensity information is recorded and not phase, and thus by collecting multiple data sets, there is enough redundant measurements to yield the original time structure, but not necessarily uniquely (or even up to an arbitrary constant phase offset). The objective of this paper is to describe another method which is simpler than FROG. Instead of collecting many auto-correlated data sets, only two spectral intensity measurements of the temporal signal are needed in the absence of noise. The first can be from the intensity components of its usual Fourier transform and the second from its FrFT (fractional Fourier transform). In the presence of noise, a minimum of four measurements are required with the same FrFT order but with two different apertures. Armed with these two or four measurements, a unique solution up to a constant phase offset can be constructed.
Lu, Xiangwen; Gao, Wenpei; Zuo, Jian-Min; Yuan, Jiabin
2015-02-01
Advances in diffraction and transmission electron microscopy (TEM) have greatly improved the prospect of three-dimensional (3D) structure reconstruction from two-dimensional (2D) images or diffraction patterns recorded in a tilt series at atomic resolution. Here, we report a new graphics processing unit (GPU) accelerated iterative transformation algorithm (ITA) based on polar fast Fourier transform for reconstructing 3D structure from 2D diffraction patterns. The algorithm also applies to image tilt series by calculating diffraction patterns from the recorded images using the projection-slice theorem. A gold icosahedral nanoparticle of 309 atoms is used as the model to test the feasibility, performance and robustness of the developed algorithm using simulations. Atomic resolution in 3D is achieved for the 309 atoms Au nanoparticle using 75 diffraction patterns covering 150° rotation. The capability demonstrated here provides an opportunity to uncover the 3D structure of small objects of nanometers in size by electron diffraction.
Roozen, N. B.; Leclère, Q.; Ege, K.; Gerges, Y.
2017-03-01
This paper presents a new wave fitting approach to estimate the frequency dependent material properties of thin isotropic plate structures from an experimentally obtained vibrational field, exciting the plate at a single point. The method projects the measurement data on to an analytical image source model, in which Hankel's functions are used for a description of the wave fields emanating from the point of excitation, including the reflected wave fields from the edges of the finite plate. By minimizing the error between the projected field and the measured field, varying the complex wave number and the source strengths of the image sources, an optimum fit is searched for. Thus the source strengths of the image sources do not need to be determined theoretically, but are estimated from the fit on to the experimental data instead (thus avoiding difficulties in theoretically assessing the reflection coefficient of the edges of the plate). The approach uses a complex wavenumber fit, enabling the determination of the dynamic stiffness of the plate structure and its damping properties as function of frequency. The method is especially suited for plates with a sufficient amount of damping, excited at high frequencies.
Couvidat, Sebastien
2012-01-01
The Helioseismic and Magnetic Imager (HMI) and the Atmospheric Imaging Assembly (AIA) instruments onboard the Solar Dynamics Observatory satellite produce Doppler velocity and continuum intensity at 6173 A as well as intensity maps at 1600 A and 1700 A, which can be used for helioseismic studies at different heights in the solar photosphere. We perform a Hankel-Fourier analysis in an annulus centered around sunspots or quiet-Sun regions, to estimate the change in power of waves crossing these regions of interest. We find that there is a dependence of power-reduction coefficients on measurement height in the photosphere: Sunspots reduce the power of outgoing waves with frequencies lower than 4.5 mHz at all heights, but enhance the power of acoustic waves in the range 4.5-5.5 mHz toward chromospheric heights, which is likely the signature of acoustic glories (halos). Maximum power reduction seems to occur near the continuum level and to decrease with altitude. Sunspots also impact the frequencies of outgoing wa...
Siddeq, M. M.; Rodrigues, M. A.
2015-09-01
Image compression techniques are widely used on 2D image 2D video 3D images and 3D video. There are many types of compression techniques and among the most popular are JPEG and JPEG2000. In this research, we introduce a new compression method based on applying a two level discrete cosine transform (DCT) and a two level discrete wavelet transform (DWT) in connection with novel compression steps for high-resolution images. The proposed image compression algorithm consists of four steps. (1) Transform an image by a two level DWT followed by a DCT to produce two matrices: DC- and AC-Matrix, or low and high frequency matrix, respectively, (2) apply a second level DCT on the DC-Matrix to generate two arrays, namely nonzero-array and zero-array, (3) apply the Minimize-Matrix-Size algorithm to the AC-Matrix and to the other high-frequencies generated by the second level DWT, (4) apply arithmetic coding to the output of previous steps. A novel decompression algorithm, Fast-Match-Search algorithm (FMS), is used to reconstruct all high-frequency matrices. The FMS-algorithm computes all compressed data probabilities by using a table of data, and then using a binary search algorithm for finding decompressed data inside the table. Thereafter, all decoded DC-values with the decoded AC-coefficients are combined in one matrix followed by inverse two levels DCT with two levels DWT. The technique is tested by compression and reconstruction of 3D surface patches. Additionally, this technique is compared with JPEG and JPEG2000 algorithm through 2D and 3D root-mean-square-error following reconstruction. The results demonstrate that the proposed compression method has better visual properties than JPEG and JPEG2000 and is able to more accurately reconstruct surface patches in 3D.
Nantian Huang
2016-11-01
Full Text Available In order to improve the recognition accuracy and efficiency of power quality disturbances (PQD in microgrids, a novel PQD feature selection and recognition method based on optimal multi-resolution fast S-transform (OMFST and classification and regression tree (CART algorithm is proposed. Firstly, OMFST is carried out according to the frequency domain characteristic of disturbance signal, and 67 features are extracted by time-frequency analysis to construct the original feature set. Subsequently, the optimal feature subset is determined by Gini importance and sorted according to an embedded feature selection method based on the Gini index. Finally, one standard error rule subtree evaluation methods were applied for cost complexity pruning. After pruning, the optimal decision tree (ODT is obtained for PQD classification. The experiments show that the new method can effectively improve the classification efficiency and accuracy with feature selection step. Simultaneously, the ODT can be constructed automatically according to the ability of feature classification. In different noise environments, the classification accuracy of the new method is higher than the method based on probabilistic neural network, extreme learning machine, and support vector machine.
Bakhos, Tania, E-mail: taniab@stanford.edu [Institute for Computational and Mathematical Engineering, Stanford University (United States); Saibaba, Arvind K. [Department of Electrical and Computer Engineering, Tufts University (United States); Kitanidis, Peter K. [Institute for Computational and Mathematical Engineering, Stanford University (United States); Department of Civil and Environmental Engineering, Stanford University (United States)
2015-10-15
We consider the problem of estimating parameters in large-scale weakly nonlinear inverse problems for which the underlying governing equations is a linear, time-dependent, parabolic partial differential equation. A major challenge in solving these inverse problems using Newton-type methods is the computational cost associated with solving the forward problem and with repeated construction of the Jacobian, which represents the sensitivity of the measurements to the unknown parameters. Forming the Jacobian can be prohibitively expensive because it requires repeated solutions of the forward and adjoint time-dependent parabolic partial differential equations corresponding to multiple sources and receivers. We propose an efficient method based on a Laplace transform-based exponential time integrator combined with a flexible Krylov subspace approach to solve the resulting shifted systems of equations efficiently. Our proposed solver speeds up the computation of the forward and adjoint problems, thus yielding significant speedup in total inversion time. We consider an application from Transient Hydraulic Tomography (THT), which is an imaging technique to estimate hydraulic parameters related to the subsurface from pressure measurements obtained by a series of pumping tests. The algorithms discussed are applied to a synthetic example taken from THT to demonstrate the resulting computational gains of this proposed method.
丁建明; 林建辉; 赵洁
2015-01-01
A new method of detecting dynamic imbalance with cardan shaft in the high-speed train is proposed applying the combination between ensemble empirical model decomposition(EEMD), Hankel matrix and singular value decomposition(SVD) contrary to the aliasing defect between the adjacent intrinsic model functions existing in the EEMD. The vibration acceleration signals of gimbal are decomposed through EEMD to get the different intrinsic model components. The Hankel matrix, which is constructed throng the single decomposition model component, is orthogonally executed through SVD. The key singular values are selected to reconstruct vibration signs on the base of the key stack of singular values. Fourier spectrum of the reconstructed signal is applied to detect dynamic imbalance with shaft and eliminates clutter spectrum caused by the aliasing defect between the adjacent intrinsic model functions, highlights the failure characteristics. The method is verified by test data in the condition of dynamic imbalance, the results show this method can effectively detect the fault vibration characteristics caused by cardan shaft dynamic imbalance and extract the nature vibration features. With comparison to the simple EEMD, the clarity and failure characterization force are significantly improved.%针对聚合经验模式分解(Ensemble empirical model decomposition, EEMD)的等效滤波特性依然存在模式分量间频带重叠较大的根本缺陷,提出一种高速列车万向轴动不平衡动态检测的新方法.该方法的核心是对万向节安装机座的振动信号进行EEMD分解得到基本模式分量,应用基本模式分量信号来构造Hankel矩阵,对该矩阵进行正交化奇异值(Singular value decomposition, SVD)分解,以奇异值关键叠层作为奇异值的选择准则对信号进行重构,应用重构信号的傅里叶谱来检测高速列车万向轴的动不平衡,消除 EEMD 分解模式频带重叠对故障特征的淹没和混淆效应,提高了
Momeni, Saba; Pourghassem, Hossein
2014-08-01
Recently image fusion has prominent role in medical image processing and is useful to diagnose and treat many diseases. Digital subtraction angiography is one of the most applicable imaging to diagnose brain vascular diseases and radiosurgery of brain. This paper proposes an automatic fuzzy-based multi-temporal fusion algorithm for 2-D digital subtraction angiography images. In this algorithm, for blood vessel map extraction, the valuable frames of brain angiography video are automatically determined to form the digital subtraction angiography images based on a novel definition of vessel dispersion generated by injected contrast material. Our proposed fusion scheme contains different fusion methods for high and low frequency contents based on the coefficient characteristic of wrapping second generation of curvelet transform and a novel content selection strategy. Our proposed content selection strategy is defined based on sample correlation of the curvelet transform coefficients. In our proposed fuzzy-based fusion scheme, the selection of curvelet coefficients are optimized by applying weighted averaging and maximum selection rules for the high frequency coefficients. For low frequency coefficients, the maximum selection rule based on local energy criterion is applied to better visual perception. Our proposed fusion algorithm is evaluated on a perfect brain angiography image dataset consisting of one hundred 2-D internal carotid rotational angiography videos. The obtained results demonstrate the effectiveness and efficiency of our proposed fusion algorithm in comparison with common and basic fusion algorithms.
Abrams, D.; Williams, C.
1999-01-01
This thesis describes several new quantum algorithms. These include a polynomial time algorithm that uses a quantum fast Fourier transform to find eigenvalues and eigenvectors of a Hamiltonian operator, and that can be applied in cases for which all know classical algorithms require exponential time.
Arc-tangent Transformation Algorithm for Active Impulsive Noise Control%有源脉冲噪声控制的反正切变换算法
邵俊; 周亚丽; 张奇志
2012-01-01
In recent years, some effective algorithms for active impulsive noise control have been proposed. But these algorithms may not be stable due to the high-and-sharp peaks of the impulsive noise. To overcome the shortage of these algorithms, a new algorithm based on minimizing the squared arc-tangent transformation of the error signal was proposed. This algorithm doesn' t need to consider thresholds estimation and parameters selection based on priori knowledge of impulsive noise. Moreover, the algorithm is simple in structure, and easy to be realized. The simulation results show that the proposed algorithm can effectively eliminate the impulsive noise, and compared with the other algorithms, the performance of the proposed algorithm has a better convergence and stability.%近年来,针对有源脉冲噪声控制,提出一些较为有效的算法.由于脉冲噪声的高尖峰特性,给算法带来了不稳定.为克服这些算法的不足,提出一种基于反正切变换的滤波x最小均方差算法.该算法不需要根据脉冲噪声的先验知识估测阈值和选择参数,并且算法结构简单、易于实现.仿真结果表明该算法能有效地消除脉冲噪声,与其他几种算法相比表现了更好的收敛性和稳定性.
A New Improved Hough Transform Algorithm for Line Extraction%一种新的改进的 Hough 变换直线提取算法
孙雪琪; 宋小春
2015-01-01
Hough transform is a better line detection method ,which has good robustness .However ,the traditional Hough transform algorithm for straight line detection ,would detect false straight line and can not detect the shorter beeline , when the long and short beeline coexist .A new and improved Hough transform method for straight line detection is proposed to solve the above problem .After extracting a straight line in the transform space of the Hough transform ,the points in the transform space accumulator units are removed ,which are transformed form all the leeliners that pass various points on the extracted line ,so as to exclude the interference of the detected straight line on the other line detecting .Finally ,the improved Hough transform algorithm is compared with traditional Hough transform method .The experimental results showed that the improved Hough algorithm has a better line detection effect .%Hough 变换具有很好的鲁棒性，是一种较好的检测直线的方法。但是，目前的 Hough 变换在长短直线并存的情况下，会检测出虚假直线并漏检较短的直线。针对以上问题论文提出了一种新的改进的 Hough 变换直线检测方法。在Hough 变换的变换空间中提取出一条直线后，将过该直线上各点的所有直线在变换空间累加器单元中对应的映射点删除，从而排除该直线对其他直线检测的干扰。最后将改进的 Hough 变换算法与传统 Hough 变换方法进行比较，实验结果显示改进的 Hough 变换算法具有更好的直线检测效果。
快速傅立叶变换中的一种倒位序生成法%AN ALGORITHM TO GENERATE REVERSE SEQUENCE IN FAST FOURIER TRANSFORM
王芳; 张学锋; 程增会
2011-01-01
快速傅立叶变换是离散傅立叶变换(DFT)的一种快速算法,它的出现使DFT的计算大大简化,运算时间可缩短一、二个数量级,从而使得离散傅立叶变换在信号分析与处理领域中得到了广泛的应用.在应用软件和硬件程序设计中要实现快速傅立叶变换算法,均涉及到序列的倒位序排列问题.针对该问题提出倒位序生成法,直接计算各自然顺序位置的倒位序数值,然后通过交址运算完成原数列的倒位序的排列.该方法对任何满足N=2M点的快速傅立叶变换,能很快实现其变换中序列的倒位序排列.该方法只涉及倒位序十进制数和顺序十进制数,不用对二进制数进行转换,简单易行,仿真实验结果证明算法可靠有效.%Fast Fourier transform is a fast algorithm of discrete Fourier transform, its appearance greatly simplifies the calculation of DFT,and the computation time can be shortened by one or two orders of magnitude thereby. For the reason of that, the discrete Fourier transform has been widely used in signal analysis and processing fields. The issue of reverse sequence is involved in programming designs of beth application software and hardware for achieving fast Fourier transform algorithm. In light of this, in the paper a generation algorithm for reverse sequence is proposed. It directly calculates the values of reverse ordinals in each natural sequential position, and then through the operation of addresses variation the ordering of reverse sequence of the primary sequence is achieved. For any FFT meets the point of N = 2M, this algorithm can quickly realise the reverse sequence ordering of the transform. The method only involves the reverse sequence decimal numeral and ordinal decimal numeral, but does not need to transform the binary numeral, it is simple and easy to implement. Simulation results show that the algorithm is reliable and effective.
宋丽娜; 王维国
2012-01-01
By constructing the iterative formula with a so-called convergence-control parameter, the generalized two-dimensional differential transform method is improved. With the enhanced technique, the nonlinear fractional Kolmogorov-Petrovskii-Piskunov equations are dealt analytically and approximate solutions are derived. The results show that the employed approach is a promising tool for solving many nonlinear fractional partial differential equations. The algorithm described in this work is expected to be employed to solve more problems in fractional calculus.
Song, Li-Na; Wang, Wei-Guo
2012-08-01
By constructing the iterative formula with a so-called convergence-control parameter, the generalized two-dimensional differential transform method is improved. With the enhanced technique, the nonlinear fractional Kolmogorov-Petrovskii-Piskunov equations are dealt analytically and approximate solutions are derived. The results show that the employed approach is a promising tool for solving many nonlinear fractional partial differential equations. The algorithm described in this work is expected to be employed to solve more problems in fractional calculus.
励刚; 苏寅生; 陈陈
2001-01-01
In the structure design of the multi-spectrum transformation implicit restarted Arnoldi (IRA) algorithm, this paper firstly decouples the main part of the IRA algorithm from multi-spectrum transformations by adopting the functional expressions, and then produces the IRA and spectrum transformation objects which are independent of each other. Furthermore, by applying the design pattern approach, and according to the relationship between the stable point-hot point structure and the template-hook structure of design patterns, a novel multi-spectrum transformation IRA algorithm structure is finally given based on design patterns. The real applications of this algorithm structure show its advantages enough in expandability, reusability and calculation efficiency of software system.%在多谱变换隐式重启动Arnoldi（IRA）算法结构设计中，采用泛函表述实现了谱变换和IRA算法解耦，产生了相对独立的IRA对象和多种谱变换对象。然后应用设计模式概念，根据多谱变换下IRA算法凝固点—热点结构和设计模式模板—挂钩结构的对应关系，提出基于设计模式结构的多谱变换IRA算法组合结构。该算法结构的实际应用充分证明了其在软件系统可伸展性、可重用性和计算效率方面的优势。
A Fingerprint Feature Extraction Algorithm Based on Wavelet Transform%一种基于小波变换的指纹特征提取算法
李峰岳; 李星野
2012-01-01
提出了一种基于小波变换的指纹纹理特征提取算法.首先以指纹图像的核心点为中心分割出一片有效的矩形区域,然后对分割后的有效区域做二维小波分解,提取小波分解后各通道的能量值作为特征值来进行识别.与传统的基于指纹细节点的识别算法相比该算法一定程度上减少了计算量,对指纹图像的质量要求也不高,并且识别精度也得到了保证.%A fingerprint feature extraction algorithm based on wavelet transform was proposed. Firstly, the paper centered on the core-points, then divided the fingerprint image into an effective area. Next, the area was analyzed by two-dimension wavelet transform, and the energy of every passage was accurately extracted as the fingerprint features. The proposed algorithm required less computational effort than conventional algorithms which were based upon minutia features extraction. In addition, this algorithm did not need the high quality fingerprint image. Besides, the correct recognition rate also reached a high level.
Chen, Hong-Yan; Zhao, Geng-Xing; Li, Xi-Can; Wang, Xiang-Feng; Li, Yu-Ling
2013-11-01
Taking the Qihe County in Shandong Province of East China as the study area, soil samples were collected from the field, and based on the hyperspectral reflectance measurement of the soil samples and the transformation with the first deviation, the spectra were denoised and compressed by discrete wavelet transform (DWT), the variables for the soil alkali hydrolysable nitrogen quantitative estimation models were selected by genetic algorithms (GA), and the estimation models for the soil alkali hydrolysable nitrogen content were built by using partial least squares (PLS) regression. The discrete wavelet transform and genetic algorithm in combining with partial least squares (DWT-GA-PLS) could not only compress the spectrum variables and reduce the model variables, but also improve the quantitative estimation accuracy of soil alkali hydrolysable nitrogen content. Based on the 1-2 levels low frequency coefficients of discrete wavelet transform, and under the condition of large scale decrement of spectrum variables, the calibration models could achieve the higher or the same prediction accuracy as the soil full spectra. The model based on the second level low frequency coefficients had the highest precision, with the model predicting R2 being 0.85, the RMSE being 8.11 mg x kg(-1), and RPD being 2.53, indicating the effectiveness of DWT-GA-PLS method in estimating soil alkali hydrolysable nitrogen content.
Lieb, Florian; Stark, Hans-Georg; Thielemann, Christiane
2017-06-01
Objective. Spike detection from extracellular recordings is a crucial preprocessing step when analyzing neuronal activity. The decision whether a specific part of the signal is a spike or not is important for any kind of other subsequent preprocessing steps, like spike sorting or burst detection in order to reduce the classification of erroneously identified spikes. Many spike detection algorithms have already been suggested, all working reasonably well whenever the signal-to-noise ratio is large enough. When the noise level is high, however, these algorithms have a poor performance. Approach. In this paper we present two new spike detection algorithms. The first is based on a stationary wavelet energy operator and the second is based on the time-frequency representation of spikes. Both algorithms are more reliable than all of the most commonly used methods. Main results. The performance of the algorithms is confirmed by using simulated data, resembling original data recorded from cortical neurons with multielectrode arrays. In order to demonstrate that the performance of the algorithms is not restricted to only one specific set of data, we also verify the performance using a simulated publicly available data set. We show that both proposed algorithms have the best performance under all tested methods, regardless of the signal-to-noise ratio in both data sets. Significance. This contribution will redound to the benefit of electrophysiological investigations of human cells. Especially the spatial and temporal analysis of neural network communications is improved by using the proposed spike detection algorithms.
Improved Algorithm of Complete Three-dimensional Euclidean Distance Transform%三维完全欧氏距离变换的改进算法
董箭; 彭认灿; 郑义东
2013-01-01
三维欧氏距离变换是对由黑白像素构成的三维二值图像中所有像素找出其到最近黑色像素的欧氏距离.在对现有三维欧氏距离变换算法进行深入研究的基础上,充分利用二维欧氏距离变换的结果,进一步减少参与距离计算和比较的黑点个数,进而提出了三维完全欧氏距离变换的改进算法.整个算法的时间复杂度为O((n3log n)/ψ (n)).并将该改进算法应用于海底污染源的扩散分析,取得了较好的效果.%The three-dimensional euclidean distance transform converts a three-dimensional image into one where each pixel has a value equal to its euclidean distance to the nearest foreground pixel. After having lucubrated the existent algorithm of three-dimensional euclidean distance transform, the paper makes full use of the result of binary euclidean distance transform to reduce the number of pixels in distance calculation and comparison, and the improved algorithm of complete three-dimensional euclidean distance transform with time complexity 0((n log n)/(p(n))has been put forward. Moreover, the improved algorithm is used to analyse pollution diffusion, and good result has been obtained.
Unaldi, Numan; Temel, Samil; Asari, Vijayan K.
2012-01-01
One of the most critical issues of Wireless Sensor Networks (WSNs) is the deployment of a limited number of sensors in order to achieve maximum coverage on a terrain. The optimal sensor deployment which enables one to minimize the consumed energy, communication time and manpower for the maintenance of the network has attracted interest with the increased number of studies conducted on the subject in the last decade. Most of the studies in the literature today are proposed for two dimensional (2D) surfaces; however, real world sensor deployments often arise on three dimensional (3D) environments. In this paper, a guided wavelet transform (WT) based deployment strategy (WTDS) for 3D terrains, in which the sensor movements are carried out within the mutation phase of the genetic algorithms (GAs) is proposed. The proposed algorithm aims to maximize the Quality of Coverage (QoC) of a WSN via deploying a limited number of sensors on a 3D surface by utilizing a probabilistic sensing model and the Bresenham's line of sight (LOS) algorithm. In addition, the method followed in this paper is novel to the literature and the performance of the proposed algorithm is compared with the Delaunay Triangulation (DT) method as well as a standard genetic algorithm based method and the results reveal that the proposed method is a more powerful and more successful method for sensor deployment on 3D terrains. PMID:22666078
Galapon, Eric A; Martinez, Kay Marie L
2014-02-08
We obtain an exactification of the Poincaré asymptotic expansion (PAE) of the Hankel integral, [Formula: see text] as [Formula: see text], using the distributional approach of McClure & Wong. We find that, for half-integer orders of the Bessel function, the exactified asymptotic series terminates, so that it gives an exact finite sum representation of the Hankel integral. For other orders, the asymptotic series does not terminate and is generally divergent, but is amenable to superasymptotic summation, i.e. by optimal truncation. For specific examples, we compare the accuracy of the optimally truncated asymptotic series owing to the McClure-Wong distributional method with owing to the Mellin-Barnes integral method. We find that the former is spectacularly more accurate than the latter, by, in some cases, more than 70 orders of magnitude for the same moderate value of b. Moreover, the exactification can lead to a resummation of the PAE when it is exact, with the resummed Poincaré series exhibiting again the same spectacular accuracy. More importantly, the distributional method may yield meaningful resummations that involve scales that are not asymptotic sequences.
手指静脉图像小波增强算法%Finger vein image enhancement algorithm based on wavelet transform
杨数强; 杨杰慧; 宋亚龙
2013-01-01
针对低质量的手指静脉图像，提出一种小波域静脉图像滤波增强算法。首先采用小波变换，然后对其低频系数进行频域增强，最后进行小波逆变换得到增强后的图像。实验表明：该方法能很好地抑制噪声，准确定位图像边缘信息，大大的改善了图像的质量，提高了图像的特征提取准确性和识别精度，使图像取得很好的增强效果。%According to the low⁃quality images of finger vein,a vein image filtering enhancement algorithm in the wavelet domain is proposed. In the algorithm,the wavelet transform is used,the parameter of the low frequency is enhanced in the frequency domain,and then the inverse wavelet transform is adopted to achieve the enhanced image. The experimental results show that the method can suppress noise perfectly,locate the image edge information accurately,improve the quality of image significantly,and enhance the extraction veracity of image features and identification accuracy. The algorithm obtained perfect efforts of image enhancement.
Sainath, Kamalesh; Teixeira, Fernando L.; Donderici, Burkay
2014-07-01
We propose the complex-plane generalization of a powerful algebraic sequence acceleration algorithm, the method of weighted averages (MWA), to guarantee exponential-cum-algebraic convergence of Fourier and Fourier-Hankel (F-H) integral transforms. This “complex-plane” MWA, effected via a linear-path detour in the complex plane, results in rapid, absolute convergence of field and potential solutions in multi-layered environments regardless of the source-observer geometry and anisotropy/loss of the media present. In this work, we first introduce a new integration path used to evaluate the field contribution arising from the radiation spectra. Subsequently, we (1) exhibit the foundational relations behind the complex-plane extension to a general Levin-type sequence convergence accelerator, (2) specialize this analysis to one member of the Levin transform family (the MWA), (3) address and circumvent restrictions, arising for two-dimensional integrals associated with wave dynamics problems, through minimal complex-plane detour restrictions and a novel partition of the integration domain, (4) develop and compare two formulations based on standard/real-axis MWA variants, and (5) present validation results and convergence characteristics for one of these two formulations.
刘婧
2011-01-01
Three-dimensional affine transformation formula and affine array fomula in three-dimensional coordi-nate system, giving a simple coordinate transformation formula are deduced and its algorithm is proved by QT class libraries based on C++ which could be applied to graphic adapter that imitates three dimension by two dimension, such as three-dimensional transformation imitation in flash and three-dimensional graphic transformation in GUI pro-gramming.%根据二维仿射变换公式推导了三维仿射变换公式,给出了三维坐标系中的仿射矩阵表示公式.同时提出了一种简单的三维到二维的坐标转换公式,并且使用基于C++的QT类库对这种算法进行了实现.这种算法可以应用于一些使用二维模拟三维的图形处理软件中,比如flash中的三维变换模拟和GUI编程中的三维图形变换等情况下.
Improved Computing-Efficiency Least-Squares Algorithm with Application to All-Pass Filter Design
Lo-Chyuan Su
2013-01-01
Full Text Available All-pass filter design can be generally achieved by solving a system of linear equations. The associated matrices involved in the set of linear equations can be further formulated as a Toeplitz-plus-Hankel form such that a matrix inversion is avoided. Consequently, the optimal filter coefficients can be solved by using computationally efficient Levinson algorithms or Cholesky decomposition technique. In this paper, based on trigonometric identities and sampling the frequency band of interest uniformly, the authors proposed closed-form expressions to compute the elements of the Toeplitz-plus-Hankel matrix required in the least-squares design of IIR all-pass filters. Simulation results confirm that the proposed method achieves good performance as well as effectiveness.
Pal, Suvra; Balakrishnan, N
2017-05-16
In this paper, we develop likelihood inference based on the expectation maximization (EM) algorithm for the Box- Cox transformation cure rate model assuming the lifetimes to follow a Weibull distribution. A simulation study is carried out to demonstrate the performance of the proposed estimation method. Through Monte Carlo simulations, we also study the effect of model mis-specification on the estimate of cure rate. Finally, we analyze a well-known data on melanoma with the model and the inferential method developed here.
A Two-dimensional Genetic Algorithm Based on the Eno-Haar Wavelet Transform%一种基于Eno-Haar小波变换二维遗传算法
宋锦萍; 赵晨萍; 李登峰
2007-01-01
A two-dimensional genetic algorithm of wavelet coefficient is presented by using the ENO wavelet transform and the decomposed characterization of the two-dimensional Haar wavelet. And simulated by the ENO interpolation the article shows the affectivity and the superiority of this algorithm.
D. Galán Martínez
2000-07-01
Full Text Available Una de las herramientas matemáticas más utilizadas en ingeniería en el estudio de los denominados sistemas de control dedatos muestreados es la transformada Z. La transformada Z como método operacional puede ser utilizada en la resoluciónde ecuaciones en diferencias finitas; las cuales formulan la dinámica de los sistemas de control de datos muestreados. Estatransformada juega un papel similar que el de la transformada de Laplace en el análisis de los sistemas de control de tiempocontinuo.El presente trabajo tiene como objetivo la confección de un programa para computadora digital, utilizando el asistentematemático DERIVE, para la determinación de la transformada Z inversa de una función algebraica racional, las cualesmodelan matemáticamente los sistemas de control de datos muestreados lineales que aparecen con mucha frecuencia en elestudio de los procesos de ingeniería.Palabras claves: Algoritmo, transformada Z, DERIVE, función algebraica racional, modelo matemático._______________________________________________________________________AbstractOne of the mathematical tools more used in engineering in the study of the denominated systems of data control samples isthe transformed Z. The transformed Z like as an operational method can be used in the resolution of equations in finitedifferences; which formulate the dynamics of the systems of data control samples. This transformed plays a similar paperthat the Laplace transformed in the analysis of the systems of control in continuous time.The present work has as objective the confection of a program for digital computer, using the mathematical assistantDERIVES, for the determination of the Z inverse transformed of a rational algebraic function, which model mathematicallythe systems of lineal data control samples that appear very frecuently in the study of the engineering processesKey words: algorithm, Z inverse transformed, Derives, Digital computer program, Rational
Li, Zhanhui; Huang, Qinghua; Xie, Xingbing; Tang, Xingong; Chang, Liao
2016-08-01
We present a generic 1D forward modeling and inversion algorithm for transient electromagnetic (TEM) data with an arbitrary horizontal transmitting loop and receivers at any depth in a layered earth. Both the Hankel and sine transforms required in the forward algorithm are calculated using the filter method. The adjoint-equation method is used to derive the formulation of data sensitivity at any depth in non-permeable media. The inversion algorithm based on this forward modeling algorithm and sensitivity formulation is developed using the Gauss-Newton iteration method combined with the Tikhonov regularization. We propose a new data-weighting method to minimize the initial model dependence that enhances the convergence stability. On a laptop with a CPU of i7-5700HQ@3.5 GHz, the inversion iteration of a 200 layered input model with a single receiver takes only 0.34 s, while it increases to only 0.53 s for the data from four receivers at a same depth. For the case of four receivers at different depths, the inversion iteration runtime increases to 1.3 s. Modeling the data with an irregular loop and an equal-area square loop indicates that the effect of the loop geometry is significant at early times and vanishes gradually along the diffusion of TEM field. For a stratified earth, inversion of data from more than one receiver is useful in noise reducing to get a more credible layered earth. However, for a resistive layer shielded below a conductive layer, increasing the number of receivers on the ground does not have significant improvement in recovering the resistive layer. Even with a down-hole TEM sounding, the shielded resistive layer cannot be recovered if all receivers are above the shielded resistive layer. However, our modeling demonstrates remarkable improvement in detecting the resistive layer with receivers in or under this layer.
基于PRI变换法的脉冲信号分选算法%Pulse Signals De-interleaving Algorithm Based on PRI Transform
乔宏乐; 王超; 王鹏
2012-01-01
脉冲重复间隔是电子对抗中信号分选的关键参数，本文研究的基于PRI变换法的信号分选算法克服了传统直方图统计法的子谐波问题，对脉冲重复间隔具有很高的估计精度，且具有很好的抗抖动性能。仿真分析表明，PRI变换法对固定PRI，抖动PRI具有很好的估计效果。%The pulse repetition interval （PRI） is a key parameter of radar signal de-interleaving in the field of elec-tronic countermeasures. The signal de-interleaving algorithm based on PRI transform overcomes the sub-harmonic problem produced in the histogram statistical method and can estimate the PRI with high precision, and possesses perfect anti - dithering capability. The simulated results indicate that PRI transform algorithm can estimate effect on fixed PRI and dithering PRI.
Wenzhu Huang
2015-04-01
Full Text Available Static strain can be detected by measuring a cross-correlation of reflection spectra from two fiber Bragg gratings (FBGs. However, the static-strain measurement resolution is limited by the dominant Gaussian noise source when using this traditional method. This paper presents a novel static-strain demodulation algorithm for FBG-based Fabry-Perot interferometers (FBG-FPs. The Hilbert transform is proposed for changing the Gaussian distribution of the two FBG-FPs’ reflection spectra, and a cross third-order cumulant is used to use the results of the Hilbert transform and get a group of noise-vanished signals which can be used to accurately calculate the wavelength difference of the two FBG-FPs. The benefit by these processes is that Gaussian noise in the spectra can be suppressed completely in theory and a higher resolution can be reached. In order to verify the precision and flexibility of this algorithm, a detailed theory model and a simulation analysis are given, and an experiment is implemented. As a result, a static-strain resolution of 0.9 nε under laboratory environment condition is achieved, showing a higher resolution than the traditional cross-correlation method.
Wei Sun
2015-01-01
Full Text Available Electric power is a kind of unstorable energy concerning the national welfare and the people’s livelihood, the stability of which is attracting more and more attention. Because the short-term power load is always interfered by various external factors with the characteristics like high volatility and instability, a single model is not suitable for short-term load forecasting due to low accuracy. In order to solve this problem, this paper proposes a new model based on wavelet transform and the least squares support vector machine (LSSVM which is optimized by fruit fly algorithm (FOA for short-term load forecasting. Wavelet transform is used to remove error points and enhance the stability of the data. Fruit fly algorithm is applied to optimize the parameters of LSSVM, avoiding the randomness and inaccuracy to parameters setting. The result of implementation of short-term load forecasting demonstrates that the hybrid model can be used in the short-term forecasting of the power system.
Lou, X M; Hassebrook, L G; Lhamon, M E; Li, J
1997-01-01
We introduce a new method for determining the number of straight lines, line angles, offsets, widths, and discontinuities in complicated images. In this method, line angles are obtained by searching the peaks of a hybrid discrete Fourier and bilinear transformed line angle spectrum. Numerical advantages and performance are demonstrated.
刘丽虹; 俞啸; 胡延军
2012-01-01
This article applied non -aliasing Contourlet transform to reconstruction algorithm of mine images based on theory of compressed sensing. Simulation indicates that reconstruction result of compressed sensing reconstructed algorithm, based on non-aliasing Contourlet transform, is better than based on traditional contourlet transform and Sym4 wavelet transform, when reconstruct one mine image with OMP algorithm under the same observing system.%将抗混叠的Contourlet变换应用到基于压缩感知理论的矿井图像重构算法中.仿真实验表明,在相同的观测系统下采用OMP算法对矿井图像进行重建时,相比于传统的Contourlet变换和Sym4小波变换,基于抗混叠Contourlet变换的压缩感知重构的图像恢复效果更佳.
基于对象的抗几何攻击的视频水印算法%Object Based Watermarking Algorithm Robust to Geometric Transformation Attacks
谌志鹏; 邹建成
2012-01-01
MPEG-4标准中基于对象的编码方法具有较好的交互性、可存取性,同时也带来了版权保护的问题.为此,提出一种基于对象的水印算法,该算法使得视频对象从一个视频序列被移动到另一个序列中,仍然能正确提取出水印.该算法通过Radon变换校正视频对象的旋转角度和缩放尺度,将水印嵌入到SA -DCT域中的部分系数中.实验结果表明,该算法能够和MPEG-4编码器有机整合、失真小,能抵抗旋转、缩放等几何攻击.%One of the key points of the MPEG-4 standard is the possibility to access and manipulate objects within a video sequence, but it increases the demand for information security protection and multimedia authentication technologies. An object based watermarking algorithm is proposed, which can correctly access the data embedded in the object. To resist against scaling and rotation attacks, two generalized Radon transformations are used. The watermark is embedded in the quantized SA-DCT coefficients. Experiments show that the algorithm is low-distortion, robust to geometry transformation attacks. And the algorithm can integrate with the MPEG-4 codec very well.
基于双树复小波变换的信号去噪算法%Signal Denoising Algorithm Based on Dual-tree Complex Wavelet Transform
刘文涛; 陈红; 蔡晓霞; 刘俊彤
2014-01-01
为了提高接收信号的质量，在一定程度上消除噪声对信号的影响，提出了一种基于双树复小波变换的信号降噪方法。通过双树结构消除了因间隔采样而丢失的有用信息，对每一层的高频分量的实部和虚部分别计算阈值，依据各自的阈值进行滤波处理。实验结果表明：该方法与离散小波变换消噪方法相比具有平移不变性，处理后的波形较平滑，能够较好地保留信号细节信息，而且其去噪性能也优于离散小波变换。%To improve the quality of received signal and eliminate the influence of noise on the signal,a signal denoising algorithm based on Dual-Tree Complex Wavelet Transform(DTCWT)is proposed. Through the double tree structure,the loss of useful information resulting from the sampling is avoided,and then the threshold of real part and imaginary part of high frequency component for each floor is calculated separately,and filter processing according to their respective threshold. Simulation results show that this algorithm has the translation invariance compared with the Discrete Wavelet Transform (DWT)denoising algorithm,and the waveform is not only relatively smooth and keeps the details of the signal better after processing,but also denoising performance is superior to the DWT.
Carracciuolo, Luisa; D'Amore, Luisa; Murli, Almerico
1998-10-01
We explore the filtering properties of wavelets functions in order to develop accurate and efficient numerical algorithms for Image Restoration problems. We propose a parallel implementation for MIMD distributed memory environments. The key insight of our approach is the use of distributed versions of Level 3 Basic Linear Algebra Subprograms as computational building blocks and the use of Basic Linear Algebra Communication Subprograms as communication building blocks for advanced architecture computers. The use of these low-level mathematical software libraries guarantees the development of efficient, portable and scalable high-level algorithms and hides many details of the parallelism from the user's point of view. Numerical experiments on a simulated image restoration applications are shown. The parallel software has been tested on a 12 nodes IBM SP2 available at the Center for Research on Parallel Computing and Supercomputers in Naples, Italy).
马春
2016-01-01
为提高计算机辅助诊断的准确性，提出一种基于小波变换和改进的模糊C均值（ Fuzzy C－Means， FCM）算法的医学CT图像分割方法。以FCM算法为基础，首先利用小波变换对医学图像进行分解，用分解后低频图像的像素点作为FCM算法的样本点；其次，利用马氏距离来进一步修正 FCM＿S（ FCM＿Spatial）算法，修正后的 FCM 算法能更加精确地反映医学图像的信息。实验结果表明，算法的效率得到较大提高。%In order to enhance the accuracy of computer auxiliary diagnosis, a medical CT image segmentation algorithm based on wavelet transform and improved FCM algorithm is proposed .Because the traditional FCM algorithm usually run on all im-age pixels, which makes the efficiency of the algorithm reduced.On the basis of FCM algorithm, firstly this algorithm processes the image using wavelet transform, and the low frequency images by wavelet transform are inputted into FCM algorithm to obtain seg-mentation results.It not only greatly reduces the time complexity of the algorithm but also effectively suppresses image noise .Sec-ondly, the algorithm introduces the Mahalanobis distance to improve FCM_S algorithm, and the improved FCM algorithm can be more accurate to obtain medical image information .The experiments show that this algorithm significantly improves the segmenta-tion’s efficiency.
Low Rank Approximation Algorithms, Implementation, Applications
Markovsky, Ivan
2012-01-01
Matrix low-rank approximation is intimately related to data modelling; a problem that arises frequently in many different fields. Low Rank Approximation: Algorithms, Implementation, Applications is a comprehensive exposition of the theory, algorithms, and applications of structured low-rank approximation. Local optimization methods and effective suboptimal convex relaxations for Toeplitz, Hankel, and Sylvester structured problems are presented. A major part of the text is devoted to application of the theory. Applications described include: system and control theory: approximate realization, model reduction, output error, and errors-in-variables identification; signal processing: harmonic retrieval, sum-of-damped exponentials, finite impulse response modeling, and array processing; machine learning: multidimensional scaling and recommender system; computer vision: algebraic curve fitting and fundamental matrix estimation; bioinformatics for microarray data analysis; chemometrics for multivariate calibration; ...
Gesture recognition algorithm and application based on coordinate transformation%一种基于坐标变换的手势识别算法及运用
齐彦甫; 陈以; 陈辉; 刘文滔; 林玲
2016-01-01
The present gesture recognition algorithms usually computes the space motion trajectory of gesture in 3D space,it includes not only many modules and algorithm complexity but also high cost.The function is too complicated and appears to be flashy without substance for in-car entertainment systems.This paper proposes a gesture recognition algorithm based on coordinate transformation and application of in-car entertainment systems. This algorithm is mainly used for gesture recognition module of in-car entertainment systems.The gesture state of the driver can be quickly and accurately identified without affecting driving and make various operations of en-tertainment system more convenient.%现有的手势识别都是采用空间算法计算手势的空间运动轨迹，模块较多、算法复杂、成本较高；同时对于车载娱乐影音系统而言功能过于繁杂，而且成本高显得华而不实。本文提出了一种基于坐标变换的手势识别算法及其在实际车载娱乐影音系统的运用。此算法主要用于车载娱乐影音系统的手势识别模块，其特点是可迅速准确识别驾驶员的手势状态，使其在不影响驾驶的情况下，更加方便地进行娱乐影音系统的各种操作。
Ron, Izhar; Zaltsman, Amalia; Kendler, Shai
2013-12-01
On-site identification of organic compounds in the presence of interfering materials using a field-portable attenuated total reflection Fourier transform infrared (ATR FT-IR) spectrometer is presented. Identification is based on an algorithm that compares the analyte's infrared absorption spectrum with the reference spectra. The comparison is performed at several predetermined frequencies, and a similarity value (distance) between the measured and the reference spectra is calculated either at each frequency individually, or, alternatively, the average distance for all frequencies is calculated. The examined frequencies are selected to give the best contrast between the target materials of interest. In this study, the algorithm was optimized to identify three common chemical warfare agents (CWAs): O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioic acid (VX), sarin (GB), and sulfur mustard (bis(2-chloroethyl) sulfide) (HD), in the presence of field-related interfering materials (fuels, water, and dust). Receiver operating characteristics analysis was performed in order to determine the probabilities for detection (PD) and for false alerts (PF). Challenging the algorithm with a set of data that contains mixtures of CWAs and interfering materials resulted in PD of 90% and PF of 0%, 0%, and 1% for VX, GB, and HD, respectively, using the average distance approach, which was found to be much more effective than analyzing each frequency individually. This finding was validated for all possible combinations of 2-7 peaks per material. It is suggested that this algorithm provides a reliable mean for the identification of a predetermined set of target analytes and interfering materials.
Ykhlef Faycal
2010-01-01
Full Text Available Problem statement: : The objective of prosody modification is to change the amplitude, duration and pitch (F0 of speech segments without altering their spectral envelop. Applications are numerous, including, Text-To-Speech synthesis, transformation of voice characteristics and foreign language learning. Several approaches have been developed in the literature to achieve this goal. The main restrictions of these latter are in the modification range, the synthesized speech quality and naturalness of spoken language. The latest research studies provide evidence that the first Formant (F1 and F0 are dependent; suggesting that in order to preserve high quality and naturalness of the speech signal, any change to one of these parameters must be accompanied by a suitable modification of the other. Approach: This study introduced a prosody modification method using combining Synchronous Overlap and Add with Fixed-Synthesis (SOLAFS algorithm and a multi level decomposition based on Discrete Wavelet Transform (DWT to overcome the limitations cited above. It used Standard Arabic (SA sounds. For a purpose of comparison, two techniques based on frame by frame processing were proposed. The first one consists in a pitch synchronous processing of the mth approximation level time segments used in SOLAFS algorithm. It was aimed to modify the prosody of the input speech without affecting the spectral envelop. The second one explores the correlation between F1 and F0 in the corresponding approximation level of SA sounded and modified duration and both F0 and F1 scales. It was based on a re-sampling method using FFT interpolation. The use of multi level analysis was aimed to provide independent control over the spectral envelope. In both techniques, the decomposition level depends on the chosen sampling Frequency (FS. F0 marking was based on multi level peaks comparison. Both techniques use an automatic speech classification algorithm based on modified version of the
Hwang, Hone-Ene; Chang, Hsuan T; Lie, Wen-Nung
2009-12-15
What we believe to be a new technique, based on a modified Gerchberg-Saxton algorithm (MGSA) and a phase modulation scheme in the Fresnel-transform domain, is proposed to reduce cross talks existing in multiple-image encryption and multiplexing. First, each plain image is encoded and multiplexed into a phase function by using the MGSA and a different wavelength/position parameter. Then all the created phase functions are phase modulated to result in different shift amounts of the reconstruction images before being combined together into a single phase-only function. Simulation results show that the cross talks between multiplexed images have been significantly reduced, compared with prior methods [Opt. Lett.30, 1306 (2005); J. Opt. A8, 391 (2006)], thus presenting high promise in increasing the multiplexing capacity and encrypting grayscale and color images.
Abdallah Bengueddoudj
2017-05-01
Full Text Available In this paper, we propose a new image fusion algorithm based on two-dimensional Scale-Mixing Complex Wavelet Transform (2D-SMCWT. The fusion of the detail 2D-SMCWT coefficients is performed via a Bayesian Maximum a Posteriori (MAP approach by considering a trivariate statistical model for the local neighboring of 2D-SMCWT coefficients. For the approximation coefficients, a new fusion rule based on the Principal Component Analysis (PCA is applied. We conduct several experiments using three different groups of multimodal medical images to evaluate the performance of the proposed method. The obtained results prove the superiority of the proposed method over the state of the art fusion methods in terms of visual quality and several commonly used metrics. Robustness of the proposed method is further tested against different types of noise. The plots of fusion metrics establish the accuracy of the proposed fusion method.
The Discrete Wavelet Transform
1991-06-01
focuses on bringing together two separately motivated implementations of the wavelet transform , the algorithm a trous and Mallat’s multiresolution...decomposition. These algorithms are special cases of a single filter bank structure, the discrete wavelet transform , the behavior of which is governed by...nonorthogonal multiresolution algorithm for which the discrete wavelet transform is exact. Moreover, we show that the commonly used Lagrange a trous
Sui, Liansheng; Liu, Benqing; Wang, Qiang; Li, Ye; Liang, Junli
2015-12-01
A color image encryption scheme is proposed based on Yang-Gu mixture amplitude-phase retrieval algorithm and two-coupled logistic map in gyrator transform domain. First, the color plaintext image is decomposed into red, green and blue components, which are scrambled individually by three random sequences generated by using the two-dimensional Sine logistic modulation map. Second, each scrambled component is encrypted into a real-valued function with stationary white noise distribution in the iterative amplitude-phase retrieval process in the gyrator transform domain, and then three obtained functions are considered as red, green and blue channels to form the color ciphertext image. Obviously, the ciphertext image is real-valued function and more convenient for storing and transmitting. In the encryption and decryption processes, the chaotic random phase mask generated based on logistic map is employed as the phase key, which means that only the initial values are used as private key and the cryptosystem has high convenience on key management. Meanwhile, the security of the cryptosystem is enhanced greatly because of high sensitivity of the private keys. Simulation results are presented to prove the security and robustness of the proposed scheme.
Image Fusion Parallel Algorithm Based on the NSCT Transforms for Multiple Images%基于NSCT变换的多源图像融合并行算法
黎宁; 张文娜
2012-01-01
Optical, infrared and radar images are the date source, using NSCT flexible transform fusion rules which is weighted average low-frequency coefficients and largest regional energy high-frequency coefficients, parallel fusion algorithm is proposed based on the NSCT transform for multiple images. A mounts of experimental results have shown that the ideal image fusion can be achieved by using different fu-sion rules especially for optical, infrared and radar images.%以可见光、红外和雷达图像为数据源,利用NSCT变换灵活的融合规则,即NSCT变换低频系数采用加权平均法、高频系数采用区域能量最大法,提出了基于NSCT变换的多源图像并行融合算法.大量图像融合实验表明,针对可见光、红外和雷达图像,采用不同的融合策略,可以得到较理想的融合图像.
Borbely, Eva
2007-01-01
A quantum algorithm is a set of instructions for a quantum computer, however, unlike algorithms in classical computer science their results cannot be guaranteed. A quantum system can undergo two types of operation, measurement and quantum state transformation, operations themselves must be unitary (reversible). Most quantum algorithms involve a series of quantum state transformations followed by a measurement. Currently very few quantum algorithms are known and no general design methodology e...
孙艳忠; 李华锋; 李保顺
2011-01-01
为了得到优质的融合图像,提出了一种新的基于非采样Contourlet变换(Nonsubsampled Contourlet Transform,NSCT)的多尺度积图像融合算法.分别讨论了低频子带与各高频子带系数的选择方案.当选择融合图像的低频子带系数时定义了一种新改进的拉普拉斯能量和(Sum modified - lplacian,SML),设计了一种基于新改进拉普拉斯能量和的加权与选择相结合系数选择方案；在选择各高频方向子带系数时,根据多尺度积具有放大信号边缘特征,降低信号噪声的特点,提出了一种基于NSCT方向多尺度积的系数选择方案,从而不仅能恰当地选择出融合图像的NSCT各方向子带系数,有效保留图像的细节特征,而且能抑制噪声对融合算法的影响.实验结果表明,该方法优于基于小波变换和提升静态小波变换的图像融合算法,得到视觉效果更好,客观评价更高的融合图像.%A novel algorithm is proposed based on the multiscale products in Nonsubsampled Contourlet Transform (NSCT) domain, for the fusion problem of the multi - source images of the same scene. In order to select the coeffi-cients of NSCT of the fusion image properly and restrain the influence of noise, the selection principles of the low fre-quency subband coefficients and bandpass subband coefficients are discussed respectively. When choosing the low frequency subband coefficients, we present a scheme based on a new sum modified - laplacian combined with the se-lection and weighted scheme; when choosing the high frequency subband, a selection scheme based on direction mul-tiscale products of NSCT is proposed according to the fact that multiscal products can enhance edges structure while weakening noise. This fusion scheme is verified on several sets of multi - source images and the experiments show that the algorithms proposed in the paper outperforms the traditional discrete wavelet transform - based and the lifting stationary wavelet
Penny, S. G.; Kalnay, E.; Carton, J. A.; Hunt, B. R.; Ide, K.; Miyoshi, T.; Chepurin, G. A.
2013-11-01
The most widely used methods of data assimilation in large-scale oceanography, such as the Simple Ocean Data Assimilation (SODA) algorithm, specify the background error covariances and thus are unable to refine the weights in the assimilation as the circulation changes. In contrast, the more computationally expensive Ensemble Kalman Filters (EnKF) such as the Local Ensemble Transform Kalman Filter (LETKF) use an ensemble of model forecasts to predict changes in the background error covariances and thus should produce more accurate analyses. The EnKFs are based on the approximation that ensemble members reflect a Gaussian probability distribution that is transformed linearly during the forecast and analysis cycle. In the presence of nonlinearity, EnKFs can gain from replacing each analysis increment by a sequence of smaller increments obtained by recursively applying the forecast model and data assimilation procedure over a single analysis cycle. This has led to the development of the "running in place" (RIP) algorithm by Kalnay and Yang (2010) and Yang et al. (2012a,b) in which the weights computed at the end of each analysis cycle are used recursively to refine the ensemble at the beginning of the analysis cycle. To date, no studies have been carried out with RIP in a global domain with real observations. This paper provides a comparison of the aforementioned assimilation methods in a set of experiments spanning seven years (1997-2003) using identical forecast models, initial conditions, and observation data. While the emphasis is on understanding the similarities and differences between the assimilation methods, comparisons are also made to independent ocean station temperature, salinity, and velocity time series, as well as ocean transports, providing information about the absolute error of each. Comparisons to independent observations are similar for the assimilation methods but the observation-minus-background temperature differences are distinctly lower for
Method of deinterleaving radar signal based on PRI transform algorithm%一种基于PRI变换的雷达信号分选方法
王海滨; 马琦
2013-01-01
With the signal environment of information warfare increasingly complicated, the radar signal sorting technology, as one of development directions of modern radar, is of great importance to radar reconnaissance. Several radar signal deinterleav-ing methods are proposed based on PRI parameter. The traditional PRI transform can overcome the subharmonic problem pro-duced in the histogram statistic methods, but has a poor performance on anti-jitter. The paper begins with a discussion of the im-proved PRI transform which overcomes the disadvantages of traditional PRI method effectively, followed by the description of the algorithm simulation. Finally, a method for sorting pulse repetition intervals of staggered PRI is discussed.%信息作战环境日益复杂,而雷达信号分选技术是作为现代信息对抗领域的重要发展方向之一,对于雷达侦察非常重要.对于雷达信号分选,基于PRI参数提出了很多分选方法.传统的PRI变换能克服直方图统计法中的子谐波问题,但抗抖动性差.讨论了修正的PRI变换分选算法,有效地克服了传统PRI变换的缺点,并对算法进行了计算机仿真.最后还讨论了重频参差抖动脉冲序列的分选方法.
Mahmud Benhamid
2009-01-01
Full Text Available Problem statement: Ultra Wide Band (UWB technology has attracted many researchers' attention due to its advantages and its great potential for future applications. The physical layer standard of Multi-band Orthogonal Frequency Division Multiplexing (MB-OFDM UWB system is defined by ECMA International. In this standard, the data sampling rate from the analog-to-digital converter to the physical layer is up to 528 M sample sec-1. Therefore, it is a challenge to realize the physical layer especially the components with high computational complexity in Very Large Scale Integration (VLSI implementation. Fast Fourier Transform (FFT block which plays an important role in MB-OFDM system is one of these components. Furthermore, the execution time of this module is only 312.5 ns. Therefore, if employing the traditional approach, high power consumption and hardware cost of the processor will be needed to meet the strict specifications of the UWB system. The objective of this study was to design an Application Specific Integrated Circuit (ASIC FFT processor for this system. The specification was defined from the system analysis and literature research. Approach: Based on the algorithm and architecture analysis, a novel Genetic Algorithm (GA based Canonical Signed Digit (CSD Multiplier less 128-point FFT processor and its inverse (IFFT for MB-OFDM UWB systems had been proposed. The proposed pipelined architecture was based on the modified Radix-22 algorithm that had same number of multipliers as that of the conventional Radix-22. However, the multiplication complexity and the ROM memory needed for storing twiddle factors coefficients could be eliminated by replacing the conventional complex multipliers with a newly proposed GA optimized CSD constant multipliers. The design had been coded in Verilog HDL and targeted Xilinx Virtex-II FPGA series. It was fully implemented and tested on real hardware using Virtex-II FG456 prototype board and logic analyzer
Carlos Andres Perez-Ramirez
2017-01-01
Full Text Available Nowadays, the accurate identification of natural frequencies and damping ratios play an important role in smart civil engineering, since they can be used for seismic design, vibration control, and condition assessment, among others. To achieve it in practical way, it is required to instrument the structure and apply techniques which are able to deal with noise-corrupted and non-linear signals, as they are common features in real-life civil structures. In this article, a two-step strategy is proposed for performing accurate modal parameters identification in an automated manner. In the first step, it is obtained and decomposed the measured signals using the natural excitation technique and the synchrosqueezed wavelet transform, respectively. Then, the second step estimates the modal parameters by solving an optimization problem employing a genetic algorithm-based approach, where the micropopulation concept is used to improve the speed convergence as well as the accuracy of the estimated values. The accuracy and effectiveness of the proposal are tested using both the simulated response of a benchmark structure and the measurements of a real eight-story building. The obtained results show that the proposed strategy can estimate the modal parameters accurately, indicating than the proposal can be considered as an alternative to perform the abovementioned task.
基于自适应稀疏变换的指纹图像压缩%Fingerprint Image Compression Algorithm via Adaptive Sparse Transformation
马名浪; 何小海; 滕奇志; 陈洪刚; 卿粼波
2016-01-01
随着指纹识别技术的广泛应用，人量指纹图像需要被收集和存储。在指纹识别系统中，对于人容量的指纹数据库，指纹图像必须压缩后存储以减少存储空间，本文提出了基于于自适应稀疏变换的指纹图像压缩算法。该算法在离线状态下提取指纹图像特征训练超完各字典；在编码过程中，首先利用差分顶测编码和稀疏变换将待压缩指纹图像转换到稀疏域，然后对直流系数和稀疏表达系数进行量化和熵编码，从而实现图像信息压缩。实验表明，在中低码率段，本文算法相比于JPEG、 JPEG2000和WSQ等主流压缩算法表现出更优越的率失真性能；在相同码率时，本文算法生成的压缩图像的主观视觉效果史好，指纹识别率史高。%With the wide application of fingerprint identification technology, a large number of fingerprint images need to be collected and stored. In fingerprint identification, as for the fingerprint database with large-capacity, the fingerprint images must be stored after compression to reduce the storage space. In this paper, a fingerprint image compression algorithm based on adaptive sparse transformation is proposed. The feature of the fingerprint image is extracted offline to train the over-complete dictionary. In the encoding process, the fingerprint image to be compressed is converted to sparse domain by utilizing the differential predictive coding and sparse transformation in the first place; after that the DC coefficients and the sparse coefficients are quantized and entropy coded to achieve the compression of the image information. Experimental results show that the proposed algorithm outperforms the mainstream compression methods, such as JPEG, JPEG2000 and WSQ, in terms of ratio-distortion performance of decoded fingerprint image, especially at low to medium bit rates. At the same bit rate, the compression image generated by the proposed algorithm exhibits
周高明; 陶亮; 王华彬; 李锐
2015-01-01
针对多窗实值离散Gabor变换（real‐valued discrete Gabor transform ，简称RDGT ），综合窗簇与分析窗簇之间双正交性关系的窗函数计算复杂性高的问题，提出一种快速窗函数求解算法。该方法利用快速离散Hartley变换（discrete Hartley transform ，简称DHT）及Hartley函数的正交性简化了窗函数的双正交条件关系式，从而降低窗函数计算复杂度。实验结果表明了该快速算法的高效性。%To reduce the high complexity of the window computation using the biorthogonal relationship between the synthesis windows and the analysis windows in the multi‐window real‐valued discrete Gabor transform (M‐RDGT ) ,this paper presented a fast algorithm .It made the bi‐orthogonal condition of computing basic window functions simpler by using fast discrete Hartley transform (DHT)and the orthogonality of the Hartley functions so that the computational complexity could be reduced .The experimental results of the algorithm also indicated that the proposed fast algorithm w as more effective .
Parallel Fast Legendre Transform
Alves de Inda, M.; Bisseling, R.H.; Maslen, D.K.
2001-01-01
We discuss a parallel implementation of a fast algorithm for the discrete polynomial Legendre transform We give an introduction to the DriscollHealy algorithm using polynomial arithmetic and present experimental results on the eciency and accuracy of our implementation The algorithms were implemente
Improved dq Transform Algorithm for Dynamic Voltage Restorer Detection%改进dq变换的动态电压恢复器检测新方法
黄永红; 施慧; 徐俊俊; 张云帅
2016-01-01
To meet the real-time and accuracy requirements for voltage sag detection in dynamic voltage restorer,an im⁃proved dq transform algorithm based on adaptive least mean square(LMS)filter and software phase-locked loop is pro⁃posed.The adaptive LMS algorithm with time delayed feedback is applied to the digital filter,which is applied to the control process of software phase-locked loop. The filtering process is conducted in advance,where instead of the tradi⁃tional low pass filter,derivative method is used to isolate the DC component under dq coordinate system instantaneous⁃ly. The proposed method can improve the accuracy of voltage sampling value,accomplish phase lock,and improve the accuracy and response speed of voltage sag detection.A simulation model built in PSCAD/EMTDC validates the ef⁃fectiveness of the proposed method .%为了满足动态电压恢复器的电压暂降检测实时性和准确性要求，提出了基于自适应最小均方LMS（least mean square）滤波器及其软件锁相环的改进dq变换新方法。结合自适应LMS算法与延时正反馈构成数字滤波器，将其应用于dq变换的软件锁相环控制过程中。并使滤波环节提前，采用求导法代替传统低通滤波器瞬时分离出dq坐标系下的直流分量。该方法可提高电压采样值的准确度，实现有效锁相，提高电压暂降检测精度及响应速度。通过PSCAD/EMTDC进行仿真验证，结果表明了该方法的有效性。
A FAST ALGORITHM OF DISCRETE GENERALIZED FOURIER TRANSFORMS ON HEXAGON DOMAINS%平行六边形区域上的快速离散傅立叶变换
孙家昶; 姚继锋
2004-01-01
In this paper, we propose a fast algorithm for computing the DGFT (Discrete Generalized Fourier Transforms) on hexagon domains [6], based on the geometric properties of the domain. Our fast algorithm (FDGFT) reduces the computation complexity of DGFT from O(N4) to O(N2 log N). In particulary, for N =2P23P34P45P56P6, the floating point computation working amount equals to(17/2P2 + 16p3 + 135/8p4 + 2424/25p5 + 201/2P6)3N2. Numerical examples are given to access our analysis.
丁建明; 王晗; 林建辉; 黄晨光
2015-01-01
针对EMD（Empirical Model Decomposition）存在模式频率混叠带来的频谱杂乱的根本缺陷，提出一种高速列车万向轴动不平衡动态检测的新方法。该方法的核心是：对万向节安装机座的振动信号进行 EMD 分解得到基本模式分量，应用基本模式分量信号来构造 Hankel 矩阵，对该矩阵进行奇异值正交化分解，以奇异值关键叠层作为奇异值的选择准则对信号进行重构，应用重构信号的傅里叶谱来检测高速列车万向轴的动不平衡，消除 EMD 分解模式频率混叠带来频谱杂乱，提高了谱的清晰度，凸显了故障特征。应用万向轴动不平衡试验数据对该方法进行试验验证，结果表明：该方法能够有效检测万向轴动不平衡引起故障特征和万向轴的固有振动特性，与纯 EMD 方法相比，该方法在谱的清晰度和故障表征力上得到了显著提高。%A new method of detecting dynamic imbalance due to cardan shaft in high-speed train was proposed applying a synthesized method of EMD (Empirical Modal Decomposition),Hankel matrix and SVD (singular value decomposition)against the aliasing defect between adjacent intrinsic model functions existing in EMD.The vibration signals of gimbal installed base were decomposed through EMD to get the different intrinsic model components.The Hankel matrix,constructed of the single decomposition model components,was orthogonally decomposed through SVD and the key singular values were selected to reconstruct the vibration signal on the base of the key stack of singular values.The Fourier spectrum of the reconstructed signal was applied to detect dynamic imbalance of shaft and the clutter spectrum caused by the aliasing defect between adjacent intrinsic model functions was eliminated so as to highlight the failure characteristics.The method was verified by test data in the condition of dynamic imbalance.The results show the method can effectively detect the
屈小波; 闫敬文; 肖弘智; 朱自谦
2008-01-01
Nonsubsampled contourlet transform (NSCT) provides flexible multiresolution, anisotropy, and directional expansion for images. Compared with the original contourlet transform, it is shift-invariant and can overcome the pseudo-Gibbs phenomena around singularities. Pulse coupled neural networks (PCNN) is a visual cortex-inspired neural network and characterized by the global coupling and pulse synchronization of neurons. It has been proven suitable for image processing and successfully employed in image fusion. In this paper, NSCT is associated with PCNN and used in image fusion to make full use of the characteristics of them. Spatial frequency in NSCT domain is input to motivate PCNN and coefficients in NSCT domain with large firing times are selected as coefficients of the fused image. Experimental results demonstrate that the proposed algorithm outperforms typical wavelet-based, contourlet-based, PCNN-based, and contourlet-PCNN-based fusion algorithms in terms of objective criteria and visual appearance.
Image Fusion Algorithms by Combining NSCT and Wavelet Transform%基于NSCT变换和小波变换相结合的图像融合算法研究
李栋; 王敬东; 李鹏
2011-01-01
针对小波变换在表达图像边界及线状特征上的缺陷,以及NSCT变换在表达图像细节信息的不足,提出了在红外图像与可见光图像融合的过程中采用基于NSCT变换和小波变换相结合的图像融合算法.在图像NSCT分解后,对低频系数使用基于小波变换的融合算法,对高频系数结合融合图像的特点采用了基于区域方差的融合规则.实验结果表明,基于NSCT变换和小波变换相结合的融合算法能更好地保持可见光图像的光谱信息和红外图像的目标信息,具有更多的细节特征以及更清晰的边缘.%An image fusion algorithm is proposed combining NSCT transform and wavelet transform in the fusion of infrared image and visible image, targeting solving the defects of boundary expression, linear features and information lack of details in NSCT transform. After NSCT, awvelet transform image fusion algorithm is adopted for low frequency coefficient while a fusion rule based on regional variances is used to fuse the high frequency coefficients by the the characteristics of the image. Experimental results show that the fusion algorithm can preserve the spectral information of visible image and target information of infrared image better than any single transform, obtaining more detailed features and sharper edge.
Quantum CPU and Quantum Algorithm
Wang, An Min
1999-01-01
Making use of an universal quantum network -- QCPU proposed by me\\upcite{My1}, it is obtained that the whole quantum network which can implement some the known quantum algorithms including Deutsch algorithm, quantum Fourier transformation, Shor's algorithm and Grover's algorithm.
刘太洪; 赵永雷
2016-01-01
为提高变压器故障诊断准确率，提出了一种基于遗传算法的动态加权模糊C均值聚类算法。该算法使用把聚类中心作为染色体的浮点数的编码方式，染色体长度可变，不同的长度对应于不同的故障聚类数；并使用权值区别不同样本点对故障划分的影响程度。将该算法应用于电力变压器油中溶解气体分析（DGA）数据分析，实现了变压器的故障诊断。经过大量实例分析，并将结果与其他算法进行对比，表明该算法具有较高的诊断精度。%ABSTRACT:In order to improve the correct rate of fault diagnosis of transformer, this paper investigates a dynamic weighted fuzzy c-means clustering algorithm based on genetic algorithm. The algorithm adopts a kind of cluster-center-based floating point encoding mode, in which the variable length chromosomes express cluster prototypes and different length of chromosomes corresponding to different numbers of cluster prototypes;besides,The algorithm utilizes the weights to express the relative degree of the importance of various data in fault partitioning. The algorithm is applied to DGA data analysis, which can accomplish fault diagnosis of the transformer. Examples analysis and comparison results show that the preci-sion of fault diagnosis can be evidently improved.
高敏; 郭业才
2012-01-01
When MMA(Multi -modulus Algorithm) is used to equalize high -order QAM, it has many disadvantages, such as slow convergence rate, large mean square error, and so on. In order to overcome the problems, an orthogonal wavelet transform weighted multi - modulus blind equalization algorithm based on simulated annealing optimization glowworm swarm algorithm ( SA - GSO - WT - MMA) was proposed. In the proposed algorithm , the weighted item was increased to the traditional multi - modulus blind equalization algorithm (MMA) , and the simulated annealing glowworm swarm optimization algorithm and the wavelet transform were also introduced in. The proposed algorithm can adjust the modulus value of the cost function value by using the weighted item, it can optimize the initial weight vector of the equalizer by using the strong global optimization ability of SA - GSO , and reduce the signal autocorrelation by using the de - correlation ability of WT. The results from computer simulation show that the proposed algorithm was excellence in improving the convergence rate and reducing the steady - state error.%为解决传统多模盲均衡算法(MMA)在均衡高阶QAM信号时存在的收敛速度慢、稳态误差大等问题,提出了一种基于模拟退火萤火虫优化的小波加权多模盲均衡算法(SA-GSO-WT-WMMA).该算法在MMA的基础上增加了加权项,并引入了模拟退火萤火虫优化(SA-GSO)算法和正交小波变换(Wr),利用加权项自适应地调整算法中代价函数的模值,利用SA-GSO算法极强的全局寻优能力来优化均衡器的初始权向量,利用正交小波变换降低信号的自相关性,有效提高了均衡效果.水声信道仿真实验表明,该算法在降低稳态均方误差和加速收敛速度两方面表现卓越.
An Improved Embedded Image Coding Algorithm Based on Wavelet Transform%一种改进的嵌入式小波图像编码算法*
陈思佳
2013-01-01
Through the analysis of the Set Partitioned Embedded Block Coder(SPECK) algorithm, propos-es a low memory overhead algorithm:listless SPECK algorithm, which against the disadvantages of the original algorithm. The algorithm reduces the memory consumption and increases the coding speed by canceling the lists of the original algorithm, this measure makes the algorithm more suitable for a fast, simple software or hardware implementation. Moreover, the algorithm output the positions of the important coefficients with the symbol and sorting information at the same time, which makes the bit allocation more reasonable and improves the compression per-formance. The experimental results verify the effectiveness of the algorithm.%通过深入分析嵌入式集合分裂块(SPECK)算法的优点与缺点，针对其优缺点对其进行改进，提出了一种低内存开销的编码算法：无链表SPECK算法。该算法通过取消原来算法中的链表结构减少内存耗费，提高算法的编码速度，从而使得该算法更易于软、硬件的实现；同时，该算法将重要系数的位信息伴随着符号信息、排序信息同时输出，使得比特分配更加合理，提高编码算法的压缩性能。实验结果验证该算法的有效性。
于虹; 孙鹏
2011-01-01
提出了基于量子遗传改进支持向量机理论的变压器故障诊断方法.该算法首先利用粗糙集技术时变压器知识进行属性约简,通过属性表获得变压器故障的最简决策表以作为支持向量机的输入,并利用量子遗传算法获得支持向量机的最优参数设置.实验结果表明,该诊断方法分类性能良好、可靠性高且有效可行.%A new fault diagnosis method is proposed for transformers, which is based on support vector machine theory improved by quantum genetic algorithm. Firstly. The algorithm is as follows: to do attribute reduction to the transformers knowledge with the technologies of rough set, to get the simple decision table for faults and imput the table into the support vector machine, and to achieve the optimum parameters setting of the support vector machine with the quantum genetic algorithm. The experimental results demonstrate that the proposed method works well in the fault classification and is reliable, effective and feasible.
Feature Extraction Using the Hough Transform
Ferguson, Tara; Baker, Doran
2002-01-01
This paper contains a brief literature survey of applications and improvements of the Hough transform, a description of the Hough transform and a few of its algorithms, and simulation examples of line and curve detection using the Hough transform.
陶星月; 陶亮
2014-01-01
To reduce the high complexity of the window computation using the biorthogonal relationship between the analysis window and the synthesis window in the Real-valued Discrete Gabor Transform(RDGT)for infinite or long sequences, this paper presents a fast algorithm based on the Discrete Hartley Transform(DHT). By transforming the equa-tion set of the biorthogonal relationship into the form of DHT, the equation set can be separated into several independent sub-equation sets so that the computational complexity can be reduced. The experimental results also indicate that the pro-posed fast algorithm is correct and effective.%为了降低在无限（长）序列实值离散Gabor变换（RDGT）中利用分析窗与综合窗之间的双正交关系计算窗函数的复杂度，提出了一种基于离散Hartley变换（DHT）的快速求解算法。通过将双正交关系式写成离散Hartley变换的形式，原方程组可被分解成若干个独立的子方程组以降低计算的复杂度。实验结果也验证了提出的快速算法的正确性和有效性。
梁浩; 王国明; 岳雨俭
2014-01-01
An improved algorithm is proposed directing against the non-blind extraction of the traditional audio watermarking and watermark’s weak security and robustness. Using Logistic chaotic sequence to modulate the watermark signal after reducing the dimensionality,Combining with the multi-resolution capabilities of discrete wavelet transform and the energy-gathered fea-tures of discrete cosine transform, watermark information is embedded in the audio carrier by modifying the intermediate or low frequency coefficient in dual-transform-domain. The simulation results show that improved algorithm owns better safety and ro-bustness performance.%针对传统音频水印算法不能实现盲提取和水印的安全性、鲁棒性不强，提出一种改进算法。采用Logistic混沌序列对降维后的水印信号作进行调制，再结合离散小波变换的多层分辨能力和离散余弦变换的能量汇聚特性，通过修改双变换域的中低频系数，在载体音频中嵌入水印信息。仿真实验表明改进算法具有更好的安全性和鲁棒性。
陈厚合; 李国庆; 姜涛
2011-01-01
The transformation strategy among converter control modes is analyzed. Considering the interaction effects between AC and DC system under different converter control modes, a new power flow algorithm that can suitable for the transformation strategy of converter control modes is proposed. Based on the sequential solution, the elements of special nodes in Jacobian matrix of AC system are effectively modified; in the transformation strategy based on converter control modes the key state variables of converter are reasonably chosen and the product of the cosine value of the control angle with the transformation ratio of transformer tap is processes as one state variable to effectively avoid the off-limit of cosine value of the control angle or that of transformer tap during the iteration. The proposed algorithm is mathematically clear and easy to achieve. Simulation results show that the proposed algorithm is accurate, rapid and reliable.%分析了换流器控制方式的转换策略。考虑在不同控制方式下交直流系统的相互影响，提出一种能够满足换流器控制方式转换策略的潮流计算方法。以顺序求解法为基础，对交流系统雅可比矩阵的特殊节点元素进行有效修正；基于换流器控制方式转换策略合理选取换流器关键状态变量，并将控制角余弦值和变压器分接头变比乘积作为一个状态变量处理，有效地避免了迭代过程中控制角余弦值或变压器分接头越限情况发生。该算法数学概念清晰、易于实现。仿真结果验证了该算法的准确性、快速性和可靠性。
脉冲噪声的非线性变换有源控制算法研究%Research active control algorithm based on nonlinear transform of impulsive noise
李沛; 张景荣
2016-01-01
α稳定分布模型是描述脉冲噪声的最佳理论工具，研究了对称α稳定分布脉冲噪声的有源控制；对基于非线性变换的脉冲噪声有源控制算法进行了推导与分析，并对FXSigmod算法进行了计算机仿真，用实验证实算法消除噪声的效果。该算法无需估测阈值，容易实现，连续更新性能好，可快速有效抑制脉冲噪声。%The alpha stable distribution provides a strong theoretical tool for the analysis of the non‐Gaussian impulsive noise signals .Active control of symmetricαstable distribution impulsive noise is studied .Impulsive noise algorithm based on nonlinear transform is derived and analyzed ,the computer simulation was carried out to validate FxSigmod algorithm .Simulation results prove the effectiveness of the algorithm .It does not need the parameter selection and thresholds estimation .it is easy to implement .Continuous update performance of algorithm is good ,which can restrain impulsive noise quickly and efficiently .
韩能霞
2014-01-01
Introduction was made to the basic principle and algorithm steps of genetic algorithm. This paper rebuilt its coding and decoding plans, restricting conditions’ treatment, searching speed and global optimization etc., so as to enable new mass body’s quality better and to quicken the optimization process. The improved genetic algorithm was adopted to carry out optimization for electromagnetic calculation de-sign of dry type power transformer, applied in the single goal and dual goal optimization design for SGB-800/10 dry type power transformer. The actual example parameters comparison and analysis show that the algorithm is actually feasible with better optimization effect.%介绍了遗传算法的基本原理及算法步骤，对其编码与解码方案、约束条件的处理、搜索速度、全局寻优等进行了改造，使新群体的整体素质更好，加快了寻优过程。采用改进的遗传算法对干式变压器的电磁计算设计进行了优化，并应用于SGB-800/10干式电力变压器的单目标和双目标的优化设计。通过实例参数对比分析，表明该算法切实可行，优化效果较好。
王本庆; 李兴国
2009-01-01
现有很多LFM信号调频斜率的分析算法,但这些算法存在诸多不足,如计算复杂、搜索时间长,对多LFM信号有交叉项等.该文提出了基于双正交Fourier变换的新LFM信号调频斜率分析算法,其特点是信号在双正交基下展开,通过变换得到信号调频斜率密度谱.该算法不需要搜索,且特别适合对不同调频斜率组成的多LFM信号进行调频斜率分析.文中推导了连续双正交Fourier变换公式和离散变换公式,并讨论了算法的一些主要性质.%There are many analysis algorithms for frequency rate of LFM signal, but those algorithms have some drawbacks, such as highly computational complexity, long time for searching, and cross-term in multi-LFM signal. In this paper, a new analysis algorithm of frequency rate of LFM signal is presented based on Biorthogonal Fourier Transform (BFT), the signal is expanded with biorthogonal base function that could be got frequency rate density spectrum of the signal. This algorithm need no searching, and has better performance for detection different frequency rate of multi-LFM signal. This paper derives continual BFT formula and discrete transform formula and discusses its some main characters.
Algorithms for Quantum Computers
Smith, Jamie
2010-01-01
This paper surveys the field of quantum computer algorithms. It gives a taste of both the breadth and the depth of the known algorithms for quantum computers, focusing on some of the more recent results. It begins with a brief review of quantum Fourier transform based algorithms, followed by quantum searching and some of its early generalizations. It continues with a more in-depth description of two more recent developments: algorithms developed in the quantum walk paradigm, followed by tensor network evaluation algorithms (which include approximating the Tutte polynomial).
金涛; 陈毅阳; 游胜强
2015-01-01
The spectral leakage has great influence on the performance of dielectric loss angle measurement when using fast Fourier transform (FFT) algorithm. Based on the analysis of the spectrum leakage effect of FFT algorithm, an improved FFT method combined Nuttall window with five-point polynomial transform to detect dielectric loss angle was presented in this paper. Since Nuttall window has a good attenuation characteristic of side lobe, and five-point polynomial transform can speed up the attenuation of side lobe spectrum, the proposed method firstly applied Nuttall window to truncate the measurement signal, then used FFT weighted polynomial transformation so as to reduce the output sequence spectrum leakage effect and improve the analysis accuracy. Through simulations and experiments, the proposed Nuttall window and five-point polynomial transform interpolated FFT algorithm is proven to be accurate and reliable. The impact factors of dielectric loss angle measurement including fundamental frequency fluctuation, number of sampling points, random noise, harmonic component, and direct current component are also analyzed in detail in this paper.%采用快速傅里叶变换（FFT）进行介质损耗角测量时，由于频谱泄漏效应会使得测量结果出现误差。在分析 FFT算法频谱泄漏效应原因基础上，提出基于 Nuttall窗-五点变换的高精度FFT算法，并将其应用于容性设备介质损耗角的测量之中。Nuttall窗具有较好的旁瓣衰减特性，对 FFT 输出序列进行加权变换则能够加快旁瓣频谱的衰减速度，因此本文算法先对被测信号加Nuttall窗，然后对FFT输出序列进行加权变换，可有效提高介质损耗角FFT算法测量的精度，从而达到减小频谱泄漏效应的目的。同时，还研究了基波频率、谐波含量、采样点数、随机噪声以及直流分量等参数对测试结果的影响。仿真和试验表明，所提方法具有较好的精度和可靠度。
张玉杰; 张媛媛
2012-01-01
针对目前视频水印算法存在的鲁棒性较差,可靠性较低等问题,提出了一种结合神经网络将二值水印嵌入到经过离散小波变换(DWT)和离散余弦变换(DCT)后的宿主视频中的新方法;为使算法具有更好的不可见性、鲁棒性和实用性,利用三层RBF神经网络训练出水印嵌入强度,在视频中自适应嵌入水印;该方法是对宿主视频进行DWT处理,再对逼近子图LL进行DCT处理,通过修改DCT系数嵌入水印信息;在嵌入之前对二值水印进行了Arnold变换来加密;通过实验结果中PSNR与NC的值表明,算法具有很强的抗攻击和承受帧删除、帧平均等操作的能力,不可感知性好,鲁棒性明显优于一般的嵌入算法.%In view of the problems that the current video algorithms have poor robustness and lower reliability, a new scheme of embedding watermarking into video based on neural network, discrete wavelet transform (DWT) and discrete cosine transform CDCT) was proposed in this paper. In order to improve the invisibility, robust and its usefulness of the algorithm, use the three-layer neural network training to get the embedded strength and embed watermark into video adaptively. The method is to do DWT for the video, then do DCT for LI,. Embed the watermarking information in the video through modifying the DCT coefficients. Before embedding, encrypt the binary watermarking by making Arnold transform. The value of PSNR and NC of the experimental results show that the new algorithm has strong ability for the attack and to bear frame dropping and frame averaging. It also has the good invisibility and robustness, and the algorithm is better than the usual embedded method.
Bao, Xingxian; Cao, Aixia; Zhang, Jing
2016-07-01
Modal parameters estimation plays an important role for structural health monitoring. Accurately estimating the modal parameters of structures is more challenging as the measured vibration response signals are contaminated with noise. This study develops a mathematical algorithm of solving the partially described inverse singular value problem (PDISVP) combined with the complex exponential (CE) method to estimate the modal parameters. The PDISVP solving method is to reconstruct an L2-norm optimized (filtered) data matrix from the measured (noisy) data matrix, when the prescribed data constraints are one or several sets of singular triplets of the matrix. The measured data matrix is Hankel structured, which is constructed based on the measured impulse response function (IRF). The reconstructed matrix must maintain the Hankel structure, and be lowered in rank as well. Once the filtered IRF is obtained, the CE method can be applied to extract the modal parameters. Two physical experiments, including a steel cantilever beam with 10 accelerometers mounted, and a steel plate with 30 accelerometers mounted, excited by an impulsive load, respectively, are investigated to test the applicability of the proposed scheme. In addition, the consistency diagram is proposed to exam the agreement among the modal parameters estimated from those different accelerometers. Results indicate that the PDISVP-CE method can significantly remove noise from measured signals and accurately estimate the modal frequencies and damping ratios.
Discrete fourier transform (DFT) analysis for applications using iterative transform methods
Dean, Bruce H. (Inventor)
2012-01-01
According to various embodiments, a method is provided for determining aberration data for an optical system. The method comprises collecting a data signal, and generating a pre-transformation algorithm. The data is pre-transformed by multiplying the data with the pre-transformation algorithm. A discrete Fourier transform of the pre-transformed data is performed in an iterative loop. The method further comprises back-transforming the data to generate aberration data.
逆向工程中对离散点云的特征识别算法探究%Feature Recognition Algorithm for Discrete Cloud Based on Wavelet Transform
张萍
2013-01-01
Because of the surface recognition problem in cloud process in reverse design, this paper presents a feature recognition algorithm for discrete cloud points based on wavelet transformation. Firstly the cloud data is denoted that the wavelet transformation can deal with, and a detailed wavelet decomposition method for 2D and 3D discrete cloud points is represented. Lastly a sample is adopted to analyze and demonstrate the algorithm. The discrete cloud points are decomposed according feature recognition algorithm and different features are extracted and these decomposed cloud data can be further processed to meet different data pretreatment requirement.%基于逆向设计中点云处理的表面识别问题，本文提出了一种基于小波变换的离散点云数据的特征识别算法。首先将离散点云表示成小波变换可以处理计算的形式，然后在此基础上提出了具体的二维和三维离散点云的小波分解算法，最后引入实例，对二维离散点云的小波分解算法进行验证分析。实验结果表明本文提出的算法达到了对点云数据的特征分解的目的。将离散点云数据按特征分解从而提取出不同的特征成分，可以根据后期点云预处理的不同要求，将小波变换后的数据进行进一步的处理。
杨涛; 任帅; 索丽; 娄棕棕; 张弢; 慕德俊
2016-01-01
Aiming at the contradiction of between invisibility and robustness and at the lack of error-detecting capacity for common information hiding algorithms, a novel algorithm based on multi-wavelet transform and QAR coding system is proposed. The digital image carrier in this scheme is preprocessed with CARDBAL2, GHM transform andlαβ color space translation, and then, the secret information coded by QAR system is embedded into preprocessed carrier for production of a stego image, thus to realize secure communication of the confidential information. The experimental results indicate that the proposed algorithm exhibits clear superiorities in invisibility, robustness and the sensitivity for distortion.%针对信息隐藏算法中常见的不可见性和鲁棒性相矛盾且不具备检错能力的缺点,提出一种新的基于多小波变换与QAR编码的信息隐藏算法.该算法利用CARDBAL2多小波变换、GHM多小波变换和lαβ颜色空间转换等方法对数字图像载体进行预处理,再将经过QAR(Quotient and remainder)编码的秘密信息嵌入到预处理后的载体图像中以生成含秘图像,从而达到将秘密信息安全传输的目的.实验结果显示,算法的优势在于其不可见性、鲁棒性和感知篡改性.
A Generalized Jacobi Algorithm
Vissing, S.; Krenk, S.
An algorithm is developed for the generalized eigenvalue problem (A - λB)φ = O where A and B are real symmetric matrices. The matrices A and B are diagonalized simultaneously by a series of generalized Jacobi transformations and all eigenvalues and eigenvectors are obtained. A criterion expressed...... in terms of the transformation parameters is used to omit transformations leading to very small changes. The algorithm is described in pseudo code for lower triangular matrices A and B and implemented in the programming Language C.......An algorithm is developed for the generalized eigenvalue problem (A - λB)φ = O where A and B are real symmetric matrices. The matrices A and B are diagonalized simultaneously by a series of generalized Jacobi transformations and all eigenvalues and eigenvectors are obtained. A criterion expressed...
赵静
2013-01-01
为了提高虹膜定位的准确率和速度,提出了一种基于二维小波变换及邻域均值滤波的虹膜定位算法.采用阈值法分割瞳孔,使用边缘检测算子检测瞳孔区域边缘,定位虹膜内边缘；然后对人眼图像进行二维小波处理降低虹膜图像的分辨率,以减少虹膜本身的纹理对判断外边缘点时所产生的影响；最后采用邻域均值滤波进行虹膜外边缘点提取,根据所得虹膜外边缘点确定虹膜外边界.仿真结果表明:该算法定位虹膜内外边界的平均时间为1.75s,准确卒为99.7％,其中虹膜外边缘定位误差小于4.2％,在虹膜识别系统中有较高的实际应用价值.%An iris localization algorithm based on two-dimensional wavelet transform and neighborhood average filter is proposed to improve the accuracy and the speed of the iris localization. Firstly, the algorithm segments the pupil area of the iris by the threshold. Secondly, it locates the iris inner edge by the edge detection operator in the pupil area. Thirdly, the human eye iris images is processed by the two-dimensional wavelet transform to reduce the image resolution, In order to reduce the impact of the iris texture on the judgment of the iris outer edge points. Fourthly, the algorithm extracts the iris outer edge points by the neighborhood average filter. Finally, it locates the iris outer edge by the outer edge points. The simulation results show that the algorithm locates the iris inner and outer edge with average time of 1. 75 s and accuracy of 99. 7%, the error of iris outer edge localization is less than 4. 2%, The algorithm has a higher practical value in the iris recognition system.
付强; 陈特放; 朱佼佼
2012-01-01
为全面有效地诊断电力机车牵引变压器故障,提出一种基于混合粒子群算法的正交小波神经网络（HP SO-WNN)方法,对牵引变压器进行综合测试和诊断.将色谱数据和电气试验数据作为正交小波神经网络的输 入量,网络隐藏层采用具有正交性的小波函数db4作为基函数,利用混合粒子群算法获得正交小波神经网络的初 始值并优化网络参数.试验结果证明,本文提出的HPSO-WNN确实可有效提高牵引变压器故障诊断速度和准 确度.%In order to diagnose traction transformer faults more effectively and in an all-round way, this paper proposed the method of the orthogonal wavelet neural network based on the hybrid particle swarm optimization algorithm (HPSO-WNN) to be applied in comprehensive tests and diagnoses of electric locomotive traction transformer faults. The chromatographic data and electrical test data worked as the inputs of the orthogonal wavelet neural network, the network's hidden layer used the orthogonal dh4 function as the basis function, and the hybrid particle swarm algorithm was used to obtain the initial values of the orthogonal wavelet neural network and to optimize the network parameters. The test results show that the proposed HPSO-WNN does effectively improve the traction transformer fault diagnosis speed and accuracy.
周业勤; 龙敏
2015-01-01
According to the properties of fractional Fourier transform, a kind of fractional Fourier transform image encryp-tion algorithm is analyzed. The key is not sensitive and the deciphering diagram is of great distortion, when with the naked eye on results chart to judge and extract the image data for comparison. Theoretical analysis and experimental results show that the algorithm is not sensitive to the key when the fractional Fourier transform is directly applied to image encryption. The introduction of RGB mapping to realize the cipher image display and transmission, result a great distortion in pixels.%从分数阶傅里叶变换的性质出发，对一类分数阶傅里叶变换图像加密算法进行分析。对原有算法结果图进行肉眼判断，提取图像中间结果数据进行对比分析，可知算法的密钥具有不敏感性，并且解密图具有很大失真。对分数傅里叶变换进行理论上的分析和讨论。分析及实验结果表明，直接使用分数阶傅里叶变换进行加密的算法对密钥并不敏感，存在安全隐患。为实现密文图像的显示和传输而引入的RGB映射将导致解密图像像素值失真。
The DM-QIM Digital Image Watermarking Algorithm Based on DCT Transformation%基于DCT变换下的DM-QIM数字图像水印算法
陈燕
2013-01-01
基于DCT域下的水印算法相对于空域中水印算法具有更好的稳定性，更大的容量，以及更好的隐蔽性，同时在借助人类的感知模型的情况下能设计出具有较好保真度的水印系统。本论文对DM-QIM(Quantization Index Modulation)水印方案进行了系统的研究，介绍了这种数字水印算法的原理及模型，探究了数字水印的嵌入和提取方案，最后对实验结果做了分析和总结。%DCT-based watermarking algorithm with respect to the airspace watermarking algorithm has strong robustness, and larger capacity, better concealment. While using human perception model can design better fidelity watermarking system. This chapter examines a DM-QIM (Quantization Index Modulation) watermarking scheme, describes the principle of the digital watermarking algorithm and model to analyze the digital watermark embedding and extraction program, finally analyzes and summarizes the experimental results.
Model Transformations? Transformation Models!
Bézivin, J.; Büttner, F.; Gogolla, M.; Jouault, F.; Kurtev, I.; Lindow, A.
2006-01-01
Much of the current work on model transformations seems essentially operational and executable in nature. Executable descriptions are necessary from the point of view of implementation. But from a conceptual point of view, transformations can also be viewed as descriptive models by stating only the
刘志军; 刘春立
2012-01-01
A kind of complex encrypting adaptive color blind watermarking algorithm was proposed based on timedomain and frequencydomain（integer wavelets domaion）.Pixel value was displaced by logistic chaotic mapping and Chebychev chaotic mapping to creat the complex chaotic sequence.Pixel position was scrambled by Arnold transform.The watermarking embedding intensity factor was counted by the DCT coefficient.A color watermarking embedding and blind extracting algorithm was designed.Algorithm experiments were produced by Matlab7.Experimental results showed that the algorithm had good transparency and strong robustness on the common watermarking attack.%提出了一种基于时域和频域（整数小波域）复合加密自适应彩色水印算法,采用Logistic混沌映射和Cheby-chev混沌映射生成复合混沌序列置换像素的值,Arnold变换置乱像素的位置,并根据离散余弦变换（discrete cosinetransform,DCT）系数计算水印嵌入强度因子,设计了彩色水印的嵌入与盲检提取算法。利用Matlab7.0平台验证了该算法,实验结果表明：该算法对常见的水印攻击不仅具有较好的透明性,而且具有较强的鲁棒性。
邱奕敏; 周毅
2015-01-01
This paper proposes a new image enhancement algorithm based on edge sharpening of wavelet coefficients for fog and haze stereoscopic images, using multi-scale characteristic of wavelet transform in order to improve the clarity of fog and haze stereoscopic images, which is mainly used in moderate pollution. The algorithm combines the depth of stereo-scopic images with multi-scale wavelet decomposition, setting a control factor in the high-frequency sub-graph to regulate contrast enhancement. And it highlights the overall outline through the sharpening of the low-frequency sub-graph. Experi-mental results show that whether PSNR or visual effect, or the subjective assessment of the DMOS value, the proposed method has better enhanced performance than the conventional edge sharpening and wavelet transform. And it has good image edge enhancement, details protection. Meanwhile, the proposed algorithm has the same computational complexity with wavelet transform.%针对立体图像在雾霾环境下的质量问题，运用小波变换的多尺度特征，提出了一种雾霾环境下的立体图像增强算法，主要用于中度污染情况下的雾霾立体图像，以提高图像资源的清晰程度。该算法将原始雾霾立体图像的深度信息与多尺度小波分解相结合，在不同尺度下分解得到的小波高频子图中设置人为操控因子，调控对比度增强的强度；锐化分解后的小波低频子图边缘来突出整体轮廓。实验从PSNR指标、视觉效果和DMOS主观评价值三个方面验证了算法的成效，该方法的增强性能均好于传统的边缘锐化和四层小波变换方法，具备很好的图像边缘增强能力，细节保护能力，且与传统小波变换有相同的算法时间复杂度。
赵静
2013-01-01
An improved iris localization algorithm of circular operator based on two-dimensional wavelet transform is proposed to im-prove the accuracy and the speed of the iris localization. Firstly,the algorithm segments the pupil area of the iris by the threshold. Second-ly it locates the iris inner edge by the edge detection operator in the pupil area. Thirdly the human eye iris image is processed by the two-dimensional wavelet transform to reduce the image resolution instead of the smoothing function in the Daugman circular operator. Finally it gets the circular edge of the sliding window by the circular edge detection operator,and compares the circle inside mean gray with the circle outside mean gray to locate the iris outer edge. The simulation results show that the algorithm locates the iris inner and outer edge with 1. 85s average time and 99. 6% accuracy rate. The algorithm has a higher practical value in the iris recognition system.% 为了提高虹膜定位的准确率和速度,提出了一种基于二维小波变换的Daugman圆形算子虹膜定位改进算法。首先采用阈值法分割瞳孔,使用边缘检测算子检测瞳孔区域边缘定位虹膜内边缘,然后采用二维小波变换对人眼图像处理以降低图像分辨率,以代替Daugman圆形算子中的平滑函数处理,最后采用圆形边缘检测算子计算滑动窗内的圆形边缘,比较滑动窗口的圆内区域与圆外区域的灰度均值来定位虹膜外边缘。仿真结果表明该算法定位虹膜内外边界的平均时间为1.85s,准确率为99.6%,在虹膜识别系统中有较高的实际应用价值。
王本庆; 曾昭林
2015-01-01
针对多进制Chirp-rate调制的通信系统解调算法由于基函数的正交性差导致实现复杂且性能不佳的特点，提出采用基于双正交Fourier变换的解调算法多进制的Chirp-rate调制行正交解调，解决了不同调频率的Chirp信号相互正交的问题，解调后可以得到信号调频率密度谱。BFT算法特点是信号在双正交基下展开，对多LFM信号分析不需要搜索，没有交叉项，特别适合对不同调频斜率组成的多LFM信号进行调频斜率分析。仿真表明其基于双正交Fourier变换的多进制Chirp-rate键控调制的解调算法具有接近MFSK误码率的性能。%According to the communication system and demodulation algorithm for M-ary Chirp-rate modulation due to the orthogonality of basis functions due to poor implementation complexity and poor performance, put forward using Chirp-rate modulation demodulation algorithm for orthogonal demodulating M-ary double orthogonal Fourier transform based on Chirp, to solve the signals of different frequency rate are orthogonal, the demodulated signal was FM density spectrum. The characteristics of the BFT algorithm is carried out in two orthogonal signal, the analysis on the multi LFM signal does not need to search, no cross terms, especially suitable for the analysis of multi LFM signal modulation slope composed of different frequency rate. Simulation results show that the demodulation algorithm for M-ary biorthogonal transform Chirp-rate key Fourier modulation based on BER performance close to MFSK.
基于提升小波变换和DCT的彩色视频水印算法%Color video watermarking algorithm based on lifting wavelet transform and DCT
熊祥光; 王力; 王端理
2013-01-01
For the copyright protection application of digital video, this paper proposed a video watermarking algorithm based on lifting wavelet transform (LWT) and discrete cosine transform (DCT). Firstly, the algorithm preprocessed the watermarking by using chaotic encryption and Arnold scrambling. Secondly, it selected randomly r color frames with a key from a video, and subdivided each channel of selected frames to non-overlapping blocks of size 8×8 and performed 1 -level LWT for each selected blocks. Finally, it applied DCT for each low-frequency sub-band of selected blocks and embedded the watermarking in the DC component by using the texture and motion characteristics of selected frame to determine adaptively the quantization step of dither modulation and could be extracted without the original video. Experimental results show that the proposed algorithm is simple and has good transparency and robustness. Compared with other algorithm, it has better performance.%针对数字视频的版权保护应用,提出了一种混合提升小波变换和DCT的视频水印算法.该算法先对水印进行混沌加密和Arnold置乱处理,借助密钥选取r帧彩色视频并将每帧视频的每一分量进行互不重叠的8×8分块,对选取的分块进行1级提升小波变换,并对低频子带进行DCT变换,以视频帧的纹理和运动特性自适应地确定量化步长的抖动调制方式嵌入水印,水印提取时无须原始视频的参与.实验表明,该算法实现简单,具有良好的透明性和鲁棒性,与其他算法相比,该算法具有更好的性能.
ERP系统中物料清单到单损耗表的转换算法%Transformation Algorithm from BOM to Unit Consumption in ERP
李浩; 李松涛
2011-01-01
结合一个实际的海关联网监管项目,实现了物料清单(BOM)到单损耗表的转换.转换过程采用深度优先算法,在遍历的基础上构造树状BOM结构,并最终按照转换规则生成单损耗表.算法使用面向对象技术,实现了数据的封装,该算法在实际项目中得到了验证.%The conversion between bill of material (BOM) and table for unit consumption is realized in a practical project of custom supervision network. The depth-first search (DFS) algorithm is adopted and the tree structure BOM is formed based on traversal. According to conversion rules,the table of unit consumption is generated. The data is encapsulated by using object-oriented techniques This algorithm is verified and applied in project.
刘少鹏; 郝群; 宋勇
2011-01-01
针对图像融合过程中边缘处理和区域一致性的问题,提出一种基于多重调和局部正弦变换的红外与可见光图像融合新算法.多重调和局部正弦变换的多重调和分量μ代表了图像缓慢变化的"趋势",在空域进行加权融合;残差分量υ体现了源图像的"波动",在傅里叶正弦变换域进行融合,以充分提取可见光图像的细节信息.由于不存在边缘效应,同时残差分量的傅里叶正弦系数具有高的消失矩,多重调和局部正弦变换应用于图像融合可取得较好的效果.多次红外与可见光图像融合实验证明所提算法有效提取了源图像有用信息,克服了多分辨率分析算法存在的边缘效应和区域一致性问题.%Aiming at the regional homogeneity and processing of the edges in course of image fusion, a novel image fusion algorithm for visible and infrared images based on polyharmonic local sine transform is proposed. The polynomial u of the source images are fused with average in order to extract the global feature, and the residual v are fused in the field of Fourier sine transform to keep region homogeneity and extract details of the visible image. The polyharmonic local sine transform avoids the disadvantages of edge effect. Combing this advantage with the quickly decaying coefficients of the residuals, polyharmonic local sine transform is effective for image fusion. Experimental results show that the proposed algorithm improves the visual effect, and enhances the contrast and information entropy.
Trusiak, Maciej; Patorski, Krzysztof; Sluzewski, Lukasz; Sunderland, Zofia
2016-04-01
In this contribution we evaluate single and two-shot techniques, namely the Hilbert spiral transform (HST) and the Gram-Schmidt orthonormalization (GSO) in terms of phase demodulation accuracy in the complex fringe patterns analysis (i.e., with strong background/contrast variations, severe noise, considerable local gradients of fringe shape/orientation). Both methods are aided by the novel Hilbert-Huang transform (HHT) processing to adaptively reduce demodulation errors. The HST utilizes a spiral phase function and a spatial fringe orientation map to demodulate phase of complex fringes. It is especially susceptible to uneven bias term and noise. The HHT method realizes bias/noise suppression adaptively with outstanding accuracy. The GSO is a fast two-shot fringe-shape-robust phase demodulation scheme. It treats two arbitrarily phase shifted interferograms as vectors and conducts orthogonal projection of one vector onto another. The GSO is susceptible to background, contrast and noise fluctuations, however. The HHT method is perfectly suitable to perform efficient pre-filtering. Both methods (HHT-HST and HHT-GSO) are proven versatile and robust to fringe pattern defects using simulation and experiment.
胡伟; 应骏
2012-01-01
结合传统的Mallat算法,利用System Generator平台,提出了一种高速二维小波变换的方法.通过实例图像(64×64)在该平台中开发相关的模块,并进行仿真和逻辑综合,最后充分体现了在System Generator中实现小波变换的优越性.%In this paper, according to the traditional Mallat algorithm, puts forward a method based FPGA of high - speed 2D wavelet transform the use of System Generator platform. Then an example (Image 64 x64) for developing,simulating and synthesizing logically module is given .finally reflect the advantage of DWT based System Generator.
NOVEL ADAPTIVE MULTIUSER DETECTIONALGORITHM BASED ON WAVELET TRANSFORM
ZHANGXiao-fei; XUDa-zhuan; YANGBei
2004-01-01
The wavelet transform-based adaptive multiuser detection algorithm is presented. The novel adaptive multiuser detection algorithm uses the wavelet transform for the preprocessing, and wavelet-transformed signal uses LMS algorithm to implement the adaptive multiuser detection. The algorithm makes use of wavelet transform to divide the wavelet space, which shows that the wavelet transform has a better decorrelation ability and leads to better convergence. White noise can be wiped off under the wavelet transform according to different characteristics of signal and white noise under the wavelet transform. Theoretical analyses and simulations demonstrate that the algorithm converges faster than the conventional adaptive multiuser detection algorithm, and has the better performance. Simulation results reveal that the algorithm convergence relates to the wavelet base, and show that the algorithm convergence gets better with the increasing of regularity for the same series of the wavelet base. Finally the algorithm shows that it can be easily implemented.
数控系统中PLC梯形图与指令表的转换算法%Algorithm on Transforming PLC Ladder Diagram to Instruction Table in NC System
罗海据; 吴永明; 梁娟
2014-01-01
In order to meet requirements of transforming the ladder diagram programmable logic controller (PLC)into an instruc-tion table for numerical control (NC)system in machine tool,the PLC ladder diagram was divided into some structural components in-cluding base-line,ring,semi-ring and ring-base-line,and etc.By using these components,the validity of PLC ladder diagram was checked,the relationship between PLC ladder diagram and instruction table was analyzed,and the algorithm about transformation from PLC ladder diagram to instruction table was designed.The application examples show that the algorithm is efficient and has good real-time,which is suitable for the NC system of machine tool.%为了满足数控机床系统中PLC梯形图向指令表转换的要求，将梯形图的构成形式分成母线、环、半环、环母线等结构元素，利用这些结构元素检验梯形图的合法性，分析梯形图和指令表之间的关系，设计梯形图向指令表快速转换的算法。应用实例表明：该算法效率高，实时性好，能满足数控机床系统的要求。
王玉德; 赵焕利; 薛乃玉
2012-01-01
从最优化的角度出发,提出了一种基于分块小波变换和二维主成分分析法(2DPCA)的人脸特征提取与识别算法.该方法首先对人脸图像进行分块小波变换,并对各分块的高、低频分量进行组合处理,然后对小波系数特征应用2DPCA方法进行变换并将分块特征进行融合得到人脸鉴别特征,最后在ORL人脸库上应用支持向量机(SVM)对该特征进行分类识别.试验结果表明,该算法能有效地提高人脸识别性能,具有较短的识别时间和较高的识别准确率,优于传统的人脸识别方法.%How to extract face recognition information from an image was investigated in this paper. A feature extraction and recognition algorithm of intersected human face based on wavelet transform and 2DPCA was proposed, by which recognition features of an image could be easily extracted for a discriminant method for face recognition. Firstly, the intersected huaman face was transformed with wavelet and different coefficients were extracted. Wavelet coefficient features were gotten by combing low frequency coefficients with high frequency coefficients of each block. Then, the 2DPCA method was used to extract features from wavelet coeficinent features and fused into ultimate discriminant features. Finally, the features were classified and recognized by SVM. The efficiency of proposed algorithm was validated.Experiment results demonstrate that the proposed method is not only good at recognition speed, but also achives a higher accuracy than classical methods.
Foundations of genetic algorithms 1991
1991-01-01
Foundations of Genetic Algorithms 1991 (FOGA 1) discusses the theoretical foundations of genetic algorithms (GA) and classifier systems.This book compiles research papers on selection and convergence, coding and representation, problem hardness, deception, classifier system design, variation and recombination, parallelization, and population divergence. Other topics include the non-uniform Walsh-schema transform; spurious correlations and premature convergence in genetic algorithms; and variable default hierarchy separation in a classifier system. The grammar-based genetic algorithm; condition
An Image Fusion Algorithm Based on Non-subsampled Contourlet Transform%基于非下采样Contourlet变换的图像融合算法
韩双喜; 储彬彬; 汪冬梅
2010-01-01
针对曲波变换图像融合的不足.提出了一种基于非下采样轮廓波变换(Non-aubsampied ContondetTransform,NSCT)图像融合方法.首先对已配准待融合罔像进行NSCT分解;然后使用相应的融合规则对Contondet域系数进行融合,得到融合图像的NSCT系数;最后经逆变换重构得到融合图像.通过对不同曝光度图像以及多聚焦图像进行融合实验,仿真结果表明该算法融合图像在董观视觉和客观评价指标上均取得良好效果.
2D Adaptive Lifting Wavelet Transform Algorithm Based on AR Model%基于AR模型的二维自适应提升小波变换算法
吕倩; 倪林; 刘权
2011-01-01
研究先更新再预测的经典自适应提升小波算法,提出一种基于自回归(AR)模型的二维自适应提升小波变换算法.根据图像局部特性选择自适应更新算子,利用更新后的系数位置关系给出基于AR模型的预测算子,使预测误差功率最小.实验结果表明,与使用最小均方误差标准的自适应预测算法相比,该算法能够降低高频系数能量,且峰值信噪比也有所提高.%This paper proposes a new algorithm for 2D adaptive lifting wavelet transform, which suites for the task of image compression applications. It is based on an update lifting operator and a prediction lifting operator according with p-order AR model of an image. It can get the coefficients of the predict filter to minimize the power of predictor error. Experimental results show that the proposed algorithm is competitive for the image compression, in terms of the decrease of the entropy of the detail coefficients and the increase of the PSNR.
焦春雨; 常文革
2013-01-01
Thinning algorithm is a vital process in road extraction.Good thinning results can provide higher efficiency and accuracy in connecting the line segments.In this article,an efficient method of thinning binary edges of UWB SAR image,which is different from traditional morphlogical thinning algorithms,is presented.Combined the theory of geometric principle axis and Hough transform,the proposed method improves the integrity of the edges after thinning while avoiding the spurs and also declines errors while calculating direction of region in thinning.It also offers a good feature of line segments for line segment connecting.%从经典形态学细化方法研究出发,结合超宽带SAR图像特点和超宽带SAR图像道路提取的应用背景,提出了一种基于几何主轴和Hough变换的超宽带SAR图像边缘细化方法.该方法克服了经典形态学细化方法边缘细化中容易出现的毛刺现象和单纯Hough变换对于区域方向判定的误差,提高了道路边缘细化的完整性.其细化后的线基元形态良好,有利于线基元连接成完整的道路.
谢铁城; 达新宇; 褚振勇; 王舒
2014-01-01
When the eigenvalue decomposition(EVD)algorithm is used to estimate the basic function for transform domain communication systems(TDCS)under the asynchronous condition,the eigenvector got by the algorithm is fuzzy,thus degrading the system performance.A synchronous method of basis function is proposed to solve this problem.Based on a detailed study of the EVD algorithm,the relational expres-sion of the data sampling delay and the eigenvalue of self-covariance matrix is deduced,and then a maxi-mum likelihood(ML)estimation algorithm of the synchronization parameter is obtained.According to the norm-equivalence theorem,the frobenius norm is introduced in the problem of finding the largest eigenval-ue in ML estimation algorithm,so the algorithm complexity is reduced.The simulation results show that the frobenius norm-based algorithm has the same performance as the largest eigenvalue-based algorithm but it only requires a less calculating time,and its estimation accuracy is in direct proportion to the signal-to-noise ratio(SNR).When the estimated basic function remains fuzzy under the asynchronous condition,the reception performance of the system can be improved by the use of basic function after synchronization.%在异步条件下应用特征值分解算法估计变换域通信系统基函数时，分段得到的特征向量存在模糊现象，此时将造成系统接收性能的下降。为了解决此问题，提出了基函数周期序列的同步算法。详细分析估计基函数的特征值分解算法，推导接收数据的采样延时与其自协方差矩阵特征值的关系式，得到同步参数的最大似然估计方法，依据范数的等价性原理，进一步将最大似然估计中的最大特征值求解问题转化为F-范数的求解以降低算法复杂度。仿真结果表明：相比最大特征值算法，采用F-范数的估计算法性能一致，但计算时间明显减少，算法的估计精度与接收信噪比成正比。异步条
冯太平; 闫仁武
2012-01-01
文中研究了非抽样Contourlet变换(NSCT)的原理,以及其多尺度、局部化、方向性和各向异性等优点.提出了一种基于NSCT的多聚焦图像融合新算法.本算法将多聚焦图像进行NSCT分解,不同子带采用不同的融合规则,低频子带采用新的基于灰度形态学梯度算子的融合算法,并做一致性检测,带通子带采用基于区域能量的融合算法.最后将融合得到的系数进行NSCT反变换得到融合图像.实验结果表明,与其他融合算法相比较,该算法可以更有效地保留源图像信息和细节特征.%The principle of nonsubsampled Contourlet transform and the advantage of multi-scale,localization directionality and anisotro-py are studied in the paper. A new multi-focus image fusion algorithm based on NSCT is developed. Firstly,two different multi-focus source images are decomposed by NSCT. Secondly,different fusion rules are applied in the low and banpass subband coefficients. A new fusion algorithm based on the gray morphology grad operator is applied in lowpass subbands and the consistency check is proposed. The regional energy fusion rule is applied in highpass subbands. Finally,the fused image is reconstructed by the inverse NSCT. The experimental results show that,compared with other algorithms,this fusion method can retain the information and features of source more effectively.
史玮; 蔡钧
2014-01-01
阻抗匹配技术在微波工程中十分重要。提出了一种基于改进遗传算法的双频带阻抗匹配的设计方法，该阻抗变换器能在2个频率点对任意电阻性负载实现理想的阻抗匹配。通过对多节传输线匹配方程的严格解，得到了双频阻抗变换器的精确设计公式，对用该方法设计的阻抗变换器性能进行了仿真分析，结果显示了该方法的有效性，可用于实际的设计。%The impedance matching technique is very important in microwave engineering. This paper proposes a dual-band impedance matching design method based on a variant of canonical Genetic Algorithm. The impedance transformer can realize ideal im-pedance matching in two frequency points in any resistive load. Based on the exact solution of multi-section transmission line matching equation, the precise design formula of dual band impedance transformer is obtained. The simulation analysis on impedance transforma-tion performances designed by the method is implemented, and the results show that the proposed method is effective and can be used in practical design.
贾旭; 薛定宇; 崔建江; 刘晶
2011-01-01
提出一种分块提取局部方向特征,并将所有特征融合的静脉识别算法.首先,静脉图像经预处理后,利用改进的细化算法对获得的二值图像进行细化处理,得到了静脉的骨架信息；其次,将细化后的静脉图像进行分块,对分块后所有的子图像进行脊波变换,并对脊波分解系数进行主成分分析(PCA)降维,得到静脉图像的特征向量；最后,基于图像特征向量,利用支持向量机(SVM)对静脉图像进行分类匹配.试验表明,该算法获得的静脉图像特征具有较高的区分度,识别效果受图像采集和预处理过程出现的误差影响较小,正确识别率可达到97％以上.%A vein recognition algorithm based on fusing all local directional features which are extracted from divided blocks is proposed. Firstly, the acquired binary image is thinned by improved thinning algorithm after vein image pre-processing and the vein skeleton information is obtained. Secondly, the thinned vein image is divided into blocks. Then, every sub-image is processed by ridgelet transforming, the dimensions of ridgelet transforming coefficients are reduced by applying principal component analysis, and the eigenvectors of vein image are acquired. Finally, vein images are classified and matched through making use of support vector machine based on the eigenvectors of image. Experimental results show that eigenvectors which are acquired through proposed algorithm have better discrimination, recognition results are affected less by errors that are generated in image acquiring and pre-processing, and the correct recognition rate exceeds 97%.
万洪林; 于海涛; 杨济民
2014-01-01
边界定位是非理想虹膜识别的关键问题之一。非理想虹膜由于经常存在纹理过强、睫毛和眼睑遮挡、虹膜巩膜对比度较差、瞳孔位置偏移等问题，这使其边界尤其是外边界定位容易出现偏差。针对上述问题，笔者提出了一种基于非线性图像增强的非理想虹膜边界定位方法。在内边界定位中，该方法首先使用混合高斯模型得到瞳孔粗略位置，然后使用弦长均衡策略搜索虹膜内边界及其中心；在外边界定位中，首先对虹膜图像进行非线性灰度变换，再利用边缘检测和改进的 Hough 变换定位虹膜外边界。实验结果表明：本算法与经典方法相比可大大提高非理想虹膜分割的准确率。%Iris boundary localization is one of the key issues of an iris recognition system.For non -ideal iris images,frequently -occurred strong texture,eyelashes or eyelids occlusion,low contrast between iris and sclera, and pupil deviation,etc,will lead inaccuracy localization of iris boundaries,particularly the outer one.We investigate this issue and propose the boundaries localization for non -ideal iris images based on the nonlinear image enhancement.In the process of inner localization,we firstly employ EM algorithm to segment pupil approximately,then use the string -equilibrium technique to search iris center and the inner boundary.In outer boundary localization,we transform nonlinearly the iris intensity,and adopt edge detector and improved Hough transform to find outer boundary.The experimental results depict that our algorithm improves the non -ideal iris localization accuracy compared to the classical algorithms.
牛曦晨; 熊家军; 李灵芝; 邱刚
2014-01-01
超视距雷达和红外预警卫星能对弹道导弹助推段进行探测跟踪，因此两者的情报可以相互关联印证，从而提高情报质量。针对超视距雷达和红外预警卫星的航迹关联问题，提出了一种基于小波变换的灰色关联度的航迹关联方法。该算法将超视距雷达和红外预警卫星的方位角信息序列通过小波变换进行去噪，得到方位角航迹的整体走势，然后对走势相同的方位角航迹建立灰色关联矩阵，并根据该矩阵按照一定的规则进行航迹相关判定。仿真结果表明，相对灰色关联度的关联算法，该算法的正确关联率提高了约8%。%Both the over-the-horizon radar and infrared early-warning satellite can detect and track the ballistic missile during the boost phase. Therefore, the intelligences out of them both can be correlated and confirmed mutually, thus improving the intelligence quality. Concerning for the track correlation of the over-the-horizon radar and infrared early-warning satellite, this paper proposes a method of track correlation using the grey correlation degree based on Wavelet transform. This proposed algorithm makes de-noising of the azimuth information sequence of the over-the-horizon radar and infrared early-warning satellite through Wavelet transform, obtains the overall trends of azimuth track, then sets up a grey correlation matrix for those azimuth track with the same trends, and finally, makes decision of track correlation according to a certain riles by this matrix. Simulation results show that the correct correlation rate using this algorithm can be improved approximately by 8%, with respect to the correlation algorithm with grey correlation degree.
Transformer Fault Diagnosis Based on C-SVC and Cross-validation Algorithm%基于支持向量机和交叉验证的变压器故障诊断
张艳; 吴玲
2012-01-01
为及时监测变压器潜伏性故障和准确诊断故障,提出基于优化惩罚因子C参数的支持向量机算法(C-SVC:C-support vector classification)和交叉验证算法相结合的变压器故障诊断方法.该方法利用变压器在故障时产生的氢气、甲烷、乙烷、乙烯、乙炔的体积分数数据建立训练集和测试集.在训练集中,该方法能自动优化出(寻找最佳)支持向量机的核函数的参数γ和惩罚因子C,利用优化的参数对训练集进行训练,可得到最佳的支持向量机模型,并用该模型对测试集进行分类,从而诊断出变压器的故障类型.变压器故障诊断实例分析结果证明,该方法可行,有效,且具有较高的故障诊断准确率.%A novel method for power transformer fault diagnosis based on the C-SVC (support vector classification with the optimized penalty parameter C) and cross-validation algorithm is presented, which can monitor and detect latent transformer faults timely and accurately. The training and testing sets of the C-SVC algorithm are built upon the data about the dissolved gases including hydrogen, methyl hydride, ethane, aethylenum and acetylene produced from transformer faults. Through the optimizing process of the penalty parameter and kernel function parameter y in the training set, the optimal support vector machine model can be gotten, with which the classification of data in the testing set can be conducted to determine fault features. The method has been validated by many practical examples to be feasible and efficient with high fault diagnosis accuracy.
A Fast Mellin and Scale Transform
Davide Rocchesso
2007-01-01
Full Text Available A fast algorithm for the discrete-scale (and β-Mellin transform is proposed. It performs a discrete-time discrete-scale approximation of the continuous-time transform, with subquadratic asymptotic complexity. The algorithm is based on a well-known relation between the Mellin and Fourier transforms, and it is practical and accurate. The paper gives some theoretical background on the Mellin, β-Mellin, and scale transforms. Then the algorithm is presented and analyzed in terms of computational complexity and precision. The effects of different interpolation procedures used in the algorithm are discussed.
Modeling of austenite to ferrite transformation
Mohsen Kazeminezhad
2012-06-01
In this research, an algorithm based on the -state Potts model is presented for modeling the austenite to ferrite transformation. In the algorithm, it is possible to exactly track boundary migration of the phase formed during transformation. In the algorithm, effects of changes in chemical free energy, strain free energy and interfacial energies of austenite–austenite, ferrite–ferrite and austenite–ferrite during transformation are considered. From the algorithm, the kinetics of transformation and mean ferrite grain size for different cooling rates are calculated. It is found that there is a good agreement between the calculated and experimental results.
Bueno, Josiane M.; Traina, Agma Juci M. [Sao Paulo Univ., Sao Carlos, SP (Brazil). Inst. de Ciencias Matematicas; Cruvinel, Paulo E. [EMBRAPA, Sao Carlos, SP (Brazil). CNPDIA
1995-12-31
This work presents an algorithm for three-dimensional digital image reconstruction. Such algorithms based on the combination of both a Fast Fourier Transform method with Hamming Window and the use of a tri-linear interpolation function. The algorithm allows not only the generation of three-dimensional spatial spin distribution maps for Magnetic Resonance Tomography data but also X and Y-rays linear attenuation coefficient maps for CT scanners. Results demonstrates the usefulness of the algorithm in three-dimensional image reconstruction by doing first two-dimensional reconstruction and rather after interpolation. The algorithm was developed in C++ language, and there are two available versions: one under the DOS environment, and the other under the UNIX/Sun environment. (author) 10 refs., 5 figs.
Quantum Computing and Shor`s Factoring Algorithm
Volovich, Igor V.
2001-01-01
Lectures on quantum computing. Contents: Algorithms. Quantum circuits. Quantum Fourier transform. Elements of number theory. Modular exponentiation. Shor`s algorithm for finding the order. Computational complexity of Schor`s algorithm. Factoring integers. NP-complete problems.
Efficient Algorithm for Asymptotics-Based CI and Electronic Structure of Transition Metal Atoms
Mendl, Christian
2010-01-01
Asymptotics-based CI methods are a class of Configuration-Interaction (CI) methods for atoms which reproduce, at fixed finite subspace dimension, the exact Schr\\"odinger eigenstates in the limit of fixed electron number and large nuclear charge. Here we develop, implement, and apply to 3d transition metal atoms an efficient and accurate algorithm for asymptotics-based CI. Efficiency gains come from exact (symbolic) decomposition of the CI space into irreducible symmetry subspaces at essentially linear computational cost, use of reduced density matrices in order to avoid having to store wavefunctions, and use of Slater-type orbitals (STO's). The required Coulomb integrals for STO's are evaluated in closed form, with the help of Hankel matrices, Fourier analysis, and residue calculus. Applications to 3d transition metal atoms are in good agreement with experimental data. In particular we reproduce the anomalous magnetic moment and orbital filling of Chromium in the otherwise regular series Ca, Sc, Ti, V, Cr.
郭洪; 李雪军
2012-01-01
针对传统NSCT(非下采样轮廓波变换)算法中NSP(多尺度分解方法)对细节信息捕捉能力较差及利用其进行图像融合得到的融合图像出现细节丢失问题,提出改进的NSCT算法.不同于传统NSCT算法,该算法首先采用细节捕捉能力较强的非下采样形态学小波分解替代NSP分解,实现对源图像的多尺度分解,将源图像分解成水平高频、垂直高频、对角高频和低频4部分；然后利用NDFB(非下采样的方向性滤波器)对高频部分进行多方向分解得到一系列高频信息,实现改进型NSCT分解.实验结果表明,该算法的细节捕捉能力较传统算法好,在相同融合规则下其图像融合效果更好,各项融合指标值均有所提高,其中平均梯度提高了10％,且易于实现,可广泛用于多分辨率图像融合,是一种有效的融合图像算法.%The NSP (multi-scale decomposition method) of the traditional NSCT (non-subsampled contourlet transform) algorithm has a poor detail information capturing ability and when applied to image fusion it causes a loss of image details. In this paper, we present an improved NSCT algorithm. Different from the traditional NSCT algorithm, we adopt the non-subsampled morphological wavelet decomposition, which has a better detail capture capability, to realize a multi-scale decomposition of the source image and replacing the NSP decomposition. The source images are decomposed into four parts: low-frequency, horizontal high-frequency, vertical high-frequency, and diagonal high-frequency. Afterwards, the improved NSCT decomposition on high frequencies using the NDFB (non-subsampled directional fdter) for multiple directions of decomposition is realized. Our experiments show that, compared with traditional algorithms, this algorithm has a better detail capturing ability, its image fusion effect is better under the same fusion rules, and all fusion indexes are improved. Among them, the average gradient is increased
Francesca Musiani
2013-08-01
Full Text Available Algorithms are increasingly often cited as one of the fundamental shaping devices of our daily, immersed-in-information existence. Their importance is acknowledged, their performance scrutinised in numerous contexts. Yet, a lot of what constitutes 'algorithms' beyond their broad definition as “encoded procedures for transforming input data into a desired output, based on specified calculations” (Gillespie, 2013 is often taken for granted. This article seeks to contribute to the discussion about 'what algorithms do' and in which ways they are artefacts of governance, providing two examples drawing from the internet and ICT realm: search engine queries and e-commerce websites’ recommendations to customers. The question of the relationship between algorithms and rules is likely to occupy an increasingly central role in the study and the practice of internet governance, in terms of both institutions’ regulation of algorithms, and algorithms’ regulation of our society.
康杰红; 马苗
2012-01-01
为提高含噪图像的分割效果和分割速度,将非下采样Contourlet变换和粒子群优化算法相结合,提出了一种有效的图像分割方法-IPSOC.该方法首先对待分割图像进行多尺度非下采样Contourlet变换,然后利用其最高级低频系数重构图像,计算重构图像与其均值图像的二维直方图中类间离散度矩阵的迹,并以之作为分割图像的目标函数来搜索最佳分割阈值.为加快阈值搜索速度,以改进的粒子群优化算法作为阈值分割的并行搜索策略,通过对基本粒子群优化算法进行个体及全局最优信息的实时更新,防止粒子停滞操作和阈值保持次数限定搜索终止条件等几个方面的改进,快速有效地获得分割图像.实验结果表明,该方法与基于遗传算法和人工鱼群算法的分割方法相比,明显提高了图像分割速度和分割质量.%In order to improve the segmentation effect and speed up the segmentation procedure of noise images, this paper proposes an efficient image segmentation method, i.e. IPSOC, which combines Nonsubsampled Contour-let Transform (NSCT) with Particle Swarm Optimization (PSO) algorithm. In this method, an original image firstly is decomposed with multi-scale NSCT transform. Then low frequency coefficients at the highest level are used to reconstruct an approximate image, and after the two-dimensional histogram of the reconstructed image and its mean-filtered image are produced, its trace of the between-class scatter matrix is taken as the object function for searching the best threshold. Simultaneously, an improved PSO algorithm is selected as the parallel scheme, which makes some progress compared to the standard PSO, such as real-time updating the individual and the global optimal information, preventing the stagnation of particles, and regarding threshold-kept times as one of the termination conditions. Experimental results show that IPSOC obviously improves both segmentation speed
张秋余; 郑兰君
2009-01-01
With the main purpose of improving the embedding capacity and concealment, using Human Auditory System (HAS) masking properties, an audio steganography algorithm based on lifting wavelet transform and matrix coding to embed secret information was proposed. MPEG I audio psychoacoustic model 1 was used to control embedding frames, middle and low frequency coefficients of lifting wavelet transform was choosen to host audio signal, and matrix coding which could improve embedding efficiency and decrease modified proportion was exploited to realize the secret information hiding. The simulation experimental results show that the algorithm not only has excellent concealment and embedding capacity, but also good robustness against noise addition, low pass filtering, resampling, MP3 compression and synchronization attack. Meanwhile, the method can realize blind extraction.%以提高隐秘信息嵌入量与隐蔽性为主要目的,利用人耳听觉系统(HAS)的掩蔽效应,提出一种结合提升小波变换和矩阵编码的嵌入隐秘信息的音频隐写算法.该算法利用MPEG I心理声学模型1来控制嵌入帧,选用宿主音频提升小波变换的中低频系数,利用能够大幅提高嵌入效率、减小修改比例的矩阵编码来实现隐秘信息的嵌入.经实验仿真证明,该算法不仅具有很好的隐蔽性和嵌入容量,还兼顾了鲁棒性,对于加噪、滤波、重采样、MP3压缩、同步攻击等常见操作具有较强的抵抗力.同时,该算法能够实现盲检测.
刘金阳; 凌翔; 许超
2015-01-01
License plate location is one of the key technologies of license plate recognition system .In order to locate the vehicle license plate rapidly and accurately ,a new license plate location algorithm based on improved pyramid transform and mathematical morphology technology is put forward .First , the algorithm of pyramid transform is applied to vehicle image to enhance image detail and reduce the impact of environment and lighting conditions change on the vehicle license plate location .Secondly , the candidate regions of license plate are identified by using image binarization and mathematical mor-phology technique .On this basis ,a new license plate extraction method is designed which first elimi-nates surrounding interference areas and then center interference areas .By the method ,the license plate location is accurately located and the license plate image is extracted eventually .Tests are done on images collected from different places and different natural conditions .The test results show that the success rate of license plate location is 99.2% and the average positioning time is 0.309 s ,thus proving that the proposed method is accurate and feasible for license plate location .%车牌定位是车牌识别系统的关键技术之一.为了快速准确地定位车牌 ,文章提出一种改进的金字塔变换和数学形态学的车牌定位算法.首先通过金字塔变换进行预处理 ,增强图像的细节信息 ,减弱环境和光照等条件变化对车牌定位的影响 ;然后利用图像二值化和数学形态学技术形成包含车牌的若干候选区 ,在此基础上设计了一种"先周边后中心"的车牌提取算法 ;最终准确定位出车牌位置 ,提取出车牌图像.通过对不同地点、不同自然条件下采集的图像进行测试 ,得出定位准确率为99.2% 、平均定位时间为0.309 s ,证明了该车牌定位算法准确可行 ,具有良好的性能.
张鑫; 徐光宪; 付晓
2012-01-01
In order to improve the ability resisting image-cropping of spread spectrum watermarking, this paper proposed a new spread spectrum watermarking algorithm based on baker' s transformation. First, it did baker' s transform of the watermarking image to scramble it, then spread the image with a PN sequence so that it could get a watermarking sequence with the ability resisting image-cropping. In the end embed the sequence into the low frequency band of the carrier image DCT domain to complete the embedding process. When checking the watermarking, cropped different area of the earner image and calculated the correlation value between the extracted watermarking image and the original image. The experimental result demonstrates that the algorithm can not only resist large area cropping, but also manifest a good robustness when facing other attacking methods.%为提高扩频水印的抗图像剪切能力,提出一种基于面包师的扩频水印算法.该算法首先利用面包师变换对水印图像进行置乱；再通过一组伪随机序列对置乱后的图像进行扩频,可得到具有抗剪切攻击能力的水印序列；最后将水印序列嵌入到载体图像DCT域中低频段部分,完成水印的嵌入.水印检测时,对载体图像分别进行不同面积的剪切,计算出提取的水印图像与原始水印图像的相关值.实验结果证明,该算法不仅能够抵抗大面积的图像剪切,同时对其他攻击方法也能够表现出良好的鲁棒性.
A Fast Algorithm for Burrows-Wheeler Transform Using Suffix Sorting%一种基于后缀排序快速实现Burrows-Wheeler变换的方法
李冰; 龙冰洁; 刘勇
2015-01-01
近年来，Bzip2压缩算法凭借其在压缩率方面的优势，得到了越来越多的应用，Bzip2的核心算法是Burrows-Wheeler变换(BWT), BWT能有效的将数据中相同的字符聚集到一起，为进一步压缩创造条件。在硬件实现 BWT 时，常用的基于后缀排序的算法能有效克服 BWT 消耗存储资源大的问题，该文对基于后缀排序实现BWT的方法进行了详细分析，并且在此基础上提出了一种快速实现BWT的方法后缀段算法。仿真结果表明后缀段算法在处理速度上比传统的基于后缀排序的算法有很大的提高。%Bzip2, a lossless compression algorithm, is widely used in recent years because of its high compression ratio. Burrows-Wheeler Transform (BWT) is the key factor in Bzip2. This method can gather the same symbols together. The traditional methods which are based on suffix sorting used in implement of BWT in hardware can solve the problem of memory consumption effectively. Detail analysis of BWT algorithm based on suffix sorting is given and a new methodSuffix segment method is presented in this paper. Experimental results show that the proposed method can much decrease BWT time consumption without increasing memory consumption much.
基于无奇异变换的双行轨道根数生成算法%Fitting algorithm of TLE parameters based on non-singular transformation
刘光明; 文援兰; 廖瑛
2011-01-01
After analyzing the space objects' two-line elements (TLE) and the simplified general perturbations 4 (SGP4) orbit prediction model, the new TLE sampling fitting method is put forward due to the singularity existence in the iterative approximation procedure. The TLE fitting algorithm deduces the partial derivative matrix of satellite position vector with respect to modified TLE parameter based on the non-singular transformation and introduces the column pivot element Givens-QR decomposition algorithm to improve the efficiency of equation solution. Numerical simulations indicate that the method can enhance the TLE fitting precision and the accuracy of forecasting orbit, especialty for the near-earth space object.%在双行轨道根数(two-line elements,TLE)和简化普适撮动轨道预报模型的基础上,针对空间目标TLE采样拟合过程中可能出现奇点的问题,提出基于无奇异变换的空间目标TLE生成算法.引入无奇异轨道根教代替开普勒根数形成改进的TLE参数,推导了目标位置矢量对改进TLE参数的偏导数矩阵,并采用选主列Givens-QR分解算法进行观测方程迭代求解,以提高数值计算稳定性.仿真结果表明,该生成算法拟合精度和位置预报残差满足要求,可应用于低轨目标的空间监视.
梁婷; 李敏; 何玉杰; 徐朋
2013-01-01
To improve the capacity and invisibility of image steganography, the article analyzed the advantage and application fields between Nonsubsampled Contourlet Transform ( NSCT) and Contourlet transform. Afterwards, an image steganography was put forward, which was based on Human Visual System (HVS) and NSCT. Through modeling the human visual masking effect, different secret massages were inserted to different coefficient separately in the high-frequency subband of NSCT. The experimental results show that, in comparison with the steganography of wavelet, the proposed algorithm can improve the capacity of steganography at least 70 000 b, and Peak Signal-to-Noise Ratio ( PSNR) increases about 4 dB. Therefore, the invisibility and embedding capacity are both considered preferably, which has a better application outlook than the wavelet project.%为提高图像信息隐藏的容量和隐蔽性,对比分析了非抽样Contourlet变换(NSCT)和Contourlet变换各自的优缺点和适用范围,提出了一种基于NSCT和人类视觉系统(HVS)的图像隐写方案.通过对人眼的视觉掩蔽效应进行建模,在NSCT分解的最精细尺度的各方向子带中,对不同系数分别嵌入不同的秘密信息量.仿真实验表明,新的算法相比小波域中的隐写方案,隐写的嵌入量至少提高了70000 b,峰值信噪比(PSNR)提高约4 dB,较好地兼顾了隐写在不可见性和嵌入容量上的要求,较小波域中的隐写方案具有更好的应用前景.
梁国龙; 陶凯; 范展
2015-01-01
In order to resolve the detection problem of passive remote weak targets under the background of strong interfer-ence ,a detection algorithm based on adaptive beam space transformation using acoustic vector sensor array is proposed .Firstly ,by designing a beamspace matrix which covers the observed sector and rejects the interference signals out-of-sector ,the array output da-ta are transformed to beamspace .Then ,the generalized likelihood ratio test is derived in beamspace .The simulation results show that the method can detect the passive weak targets efficiently under the background of strong interference ,and provide the constant false alarm rate (CFAR ) detection .%为了解决水下强干扰背景下的远程弱目标被动探测问题，基于声矢量阵，本文提出了一种自适应波束域的检测算法。该算法首先对阵列接收数据进行波束域变换，令通带覆盖整个观测扇面，并自适应地抑制扇面外的强干扰信号；然后在波束域进行广义似然比检测。仿真结果表明，该算法能在强干扰背景下实现对远程弱目标的检测，并且具有恒虚警率特性。
姚睿; 张艳宁; 孙瑾秋; 张永鹏
2011-01-01
When the frame transfer CCD image sensor shooting star-sky background image, the smear phenomenon caused by high brightness stars in the field of view will seriously affect the target detection.For removing the smear phenomenon,a smear removal algorithm based on wavelet transform in star-sky image was proposed. According to the mechanism of smear and characteristics of the star-sky image, the model of smear problem was established, the smear line was separated into the high frequency components and vertical components by using multi-layer two-dimension haar wavelet transform, and the smearremoved image was reconstructed. The expirmental results show that the method can effectively remove smear and retain original image information,and enhance the SNR of small target in smear area.%帧转移型CCD传感器在拍摄星空背景图像时,视场中高亮度恒星会产生Smear现象,从而对目标检测有严重影响.为了消除Smear现象,提出了一种星图中基于小波变换的Smear消除方法.首先根据Smear产生机理及星空图像特性,建立星图Smear问题的模型;然后使用多层二维Haar小波分解,把Smear亮线分离到低频分量及高频垂直分量中分别进行Snlear消除处理;最后重构出消除Smear的图像.实验结果表明:该方法能有效去除Smear,最大限度保留图像原有信息,并可增强Smear区域弱小目标信噪比.
魏兴瑜; 周涛; 陆惠玲; 王文文
2015-01-01
PET/CT医学图像融合对于图像分析及临床诊断具有重要的应用价值，通过融合PET/CT图像，可以丰富图像的信息量，提高信息准确度。针对PET/CT融合问题，提出了一个基于双树复小波的PET/CT自适应融合算法。对已配准的PET和CT图像进行双树复小波变换（dual-tree complex wavelet transform，DTCWT），得到低频分量和高频分量；根据低频图像集中了大部分源图像能量及决定了图像轮廓的特点，采用了自适应高斯隶属度函数的融合规则；在高频图像部分，考虑了图像相邻像素之间的相关性和模糊性问题，在第一层的高频分量上采用了高斯隶属度函数和3×3领域窗口相结合的融合规则，在第二层高频分量上采用了区域方差的融合规则。最后，为了验证算法的有效性和可行性，做了3个方面的实验，分别是该算法和其他像素级融合算法的比较实验，利用信息熵、均值、标准方差和互信息的融合效果评价实验，双树复小波变换中不同融合规则的比较实验。实验结果表明，该算法信息熵提高了7.23%，互信息提高了17.98%，说明该算法是一种有效的多模态医学影像融合方法。%PET/CT medical image fusion has very important application value for medical image analysis and diseases diagnosis. It is useful to improve the image content and accuracy by fusing PET/CT images. Aiming at PET/CT fusion problem, this paper proposes a self-adaption fusion algorithm of PET/CT based on dual-tree complex wavelet trans-form. Firstly, source PET and CT images after registration are decomposed low and high frequency sub-images using dual-tree complex wavelet transform (DTCWT). Secondly, according to the characteristics of low frequency sub-images concentrating the majority energy of the source image and determining the image contour, a fusion rule based on self-adaption Gaussian membership function is adopted in low
A Parallel Butterfly Algorithm
Poulson, Jack
2014-02-04
The butterfly algorithm is a fast algorithm which approximately evaluates a discrete analogue of the integral transform (Equation Presented.) at large numbers of target points when the kernel, K(x, y), is approximately low-rank when restricted to subdomains satisfying a certain simple geometric condition. In d dimensions with O(Nd) quasi-uniformly distributed source and target points, when each appropriate submatrix of K is approximately rank-r, the running time of the algorithm is at most O(r2Nd logN). A parallelization of the butterfly algorithm is introduced which, assuming a message latency of α and per-process inverse bandwidth of β, executes in at most (Equation Presented.) time using p processes. This parallel algorithm was then instantiated in the form of the open-source DistButterfly library for the special case where K(x, y) = exp(iΦ(x, y)), where Φ(x, y) is a black-box, sufficiently smooth, real-valued phase function. Experiments on Blue Gene/Q demonstrate impressive strong-scaling results for important classes of phase functions. Using quasi-uniform sources, hyperbolic Radon transforms, and an analogue of a three-dimensional generalized Radon transform were, respectively, observed to strong-scale from 1-node/16-cores up to 1024-nodes/16,384-cores with greater than 90% and 82% efficiency, respectively. © 2014 Society for Industrial and Applied Mathematics.
陈小青; 刘觉民; 黄英伟; 付波
2012-01-01
传统的人工智能方法对变压器大量的不完备故障信息不能有效地分析,或在故障数据的离散化过程中由于区间分割不当而无法正确诊断故障甚至误诊。为此,提出了一种基于改进人工鱼群优化粗糙集的变压器故障诊断方法。该方法首先将变压器溶解气体分析（DGA）的值作为条件属性,将故障类型作为决策属性,建立故障决策表,利用鱼群的聚群寻优行为对决策表中的连续属性数据进行离散化;然后采用粗糙集理论对离散化后的决策表进行约简,建立故障诊断规则决策表,大大简化了决策表属性约简的难度,使诊断变得更加简便。最后通过实例验证表明：该方法能够有效地对样本进行离散和约简,与传统方法相比,提高了故障诊断的正确率。%Facing a large number of incomplete fault data, the traditional artificial intelligence methods cannot effectively and timely analyze or accurately diagnosed because of the ill-conditioned problem caused by inefficient discretization approaches. We presented a method based on rough set theory integrated with improved artificial fish swarm algorithm {AFSA} for fault diagnosis of transformer. Firstly, the values of dissolved gas analysis {DGA） in oil were taken as conditional attributes and the type faults were taken as decision attributes. Various relations between fault and symptom were connected, and decision table was established. Then, the improved artificial fish swarm algorithm was used to discrete continuous attribute, and the rough set theory was used to reduce the decision table. Finally, the simplified decision rules were got, which greatly simplified the difficulty of diagnosis. The experimental results indicate that the method increases the diagnosis accuracy compared with the traditional algorithm.
Tactical Synthesis Of Efficient Global Search Algorithms
Nedunuri, Srinivas; Smith, Douglas R.; Cook, William R.
2009-01-01
Algorithm synthesis transforms a formal specification into an efficient algorithm to solve a problem. Algorithm synthesis in Specware combines the formal specification of a problem with a high-level algorithm strategy. To derive an efficient algorithm, a developer must define operators that refine the algorithm by combining the generic operators in the algorithm with the details of the problem specification. This derivation requires skill and a deep understanding of the problem and the algorithmic strategy. In this paper we introduce two tactics to ease this process. The tactics serve a similar purpose to tactics used for determining indefinite integrals in calculus, that is suggesting possible ways to attack the problem.
基于NSCT和PCA变换域的遥感图像融合算法%Remote sensing image fusion algorithm based on NSCT and PCA transform-domain
孙岩; 赵春晖; 江凌
2011-01-01
为使融合后的图像在尽可能保持原图像光谱信息的同时,有效提高空间细节信息,提出了一种新的基于非下采样Contourlet变换(NSCT)和主成分分析(PCA)的全色图像和多光谱图像融合算法.对多光谱图像进行PCA变换得到主元分量,将处理后的主元分量与全色图像进行NSCT分解,针对低频子带系数选择提出了一种基于窗口与局部方差相结合的融合策略;在高频子带系数选择上,提出了基于区域线性相关测定的融合策略.进行非下采样Contourlet逆变换和PCA逆变换,得到具有高空间质量的多光谱图像,实验结果表明,提出的算法在保留光谱信息和提高空间细节信息的综合性能上有所提高,能够取得较好的融合效果.%In order to preserve possibly the spectral information and enhance synchronously the spatial detail information for the fused image, a novel panchromatic and multispectral image fusion algorithm based on nonsubsampled contourlet transform (NSCT) and principal component analysis (PCA) was proposed. The principal component was obtained by PCA transformation for multispectral image. The NSCT decomposition was performed for the processed principal component and panchromatic image. The fusion strategy combined window with local variance was proposed for the low-frequency band coefficient choice. And the fusion strategy based on regional linear relativity measurement was proposed for the high-frequency band coefficient choice. A fused multispectral image with high spatial quality was obtained through performing inverse NSCT and PCA transforms. The experimental results show that the proposed fusion scheme can improve the comprehensive properties in preserving the spectral information and improving the spatial detail information, and achieve better fusion effect.
时丕丽; 郭雷; 李晖晖; 杨宁; 陈智慧
2012-01-01
SAR image or multispectral image has big difference in imaging mechanism and spectral characteristics. Sections 1 and 2 of the full paper explain our image fusion method mentioned in the title, which we believe is new and better than previous ones. Their cpre consists of : (1) by using the multi-scale, multi-direction ad spare decomposition capability of the NSCT, we transform the SAR and multispectral source images into NSCT domain; (2) we fuse the low frequencey coefficients by maximizing the regional entropy; then we calculate the values of the high-frequence subband regional correlation coefficients, divide them into different ranges according to the threshold values selected by genetic algorithm and fuse the correlation coefficients in different ranges, ( 3) we take the inverse NSCT transform, thus obtatining the fused images. Section 3 simulates our image fusion method; the simulation results , given in Fig. 4 and Table 1, and their analysis show preliminarily that our image fusion method performs indeed much better than the exsiting regional-based/pixel-based Contourlet/NSCT.%合成孔径雷达(SAR)图像与多光谱图像成像机理和光谱特性差异较大,一般的融合方法很难取得满意的融合结果.文章提出了一种基于Nonsuosampled Contourlet transform(NSCT)和遗传算法的融合算法,首先将经过预处理后的图像进行NSCT分解,低频系数采取区域信息熵最大的准则融合；高频子带计算区域相关性,对相关性在不同阈值范围内的系数进行融合,阈值的选取采用遗传算法进行搜索；最后对融合系数进行NSCT逆变换,得到融合结果.仿真结果表明该算法显著优于基于像素点和基于区域的融合方法.
陈家杰; 李会元; 张先轶
2012-01-01
In this paper, we study the parallel algorithm based on CUDA and MPI for the Fast Fourier Transform on the hexagon (FFTH) and its implementation. Firstly, we design a CUDA FFTH algorithm by utilizing the hierachical parallelization mechanism and the build-in CUFFT library for classic rectangular FFTs. With respect to the serial cpu program, our CUDA program achieves 12x speedup for 3 × 20482 double-precision complex-to-complex FFTH. If we ignore the PCI between main memory and GPU device memory, around 30x-40x speedup can be even achieved. Although the non-tensorial FFTH is much more complicated than the rectangular FFT, our CUDA FFTH program gains the same efficiency as the rectangular CUFFT. Next, efforts are mainly contributed to optimization techniques for parallel array transposition and data sorting, which significantly improve the efficiency of the CUDA-MPI FFTH algorithm. On a 10-node cluster with 60 GPUs, our CUDA-MPI program achieves about 55x speedup with respect to the the serial cpu program for 3 × 81922 complex-to-complex double-precision FFTH, and it is more efficient than the MPI parallel FFTW. Our research on the CUDA-MPI algorithm for FFTH is beneficial to the exploration and development of new parallel algorithms on large-scale CPU-GPU heterogeneous computer systems.%本文研究六边形区域上快速傅里叶变换(FFTH)的CUDA-MPI算法及其实现.首先,我们通过充分利用CUDA的层次化并行机制及其库函数,设计了FFTH的高效率的CUDA算法.对于规模为3×20482的双精度复数类型数据,我们设计的CUDA程序与CPU串行程序相比可以达到12倍加速比,如果不计内存和显存之间的数据传输,则加速比可达40倍;其计算效率与CUFFT所提供的二维方形区域FFT程序的效率基本一致.在此基础上,我们通过研究GPU上分布式并行数据的转置与排序算法,优化设计了FFTH的CUDA-MPI算法.在3×81922的数据规模、10节点×6GPU的计算环境下,我们的CUDA
Search for New Quantum Algorithms
2006-05-01
Topological computing for beginners, (slide presentation), Lecture Notes for Chapter 9 - Physics 219 - Quantum Computation. (http...14 II.A.8. A QHS algorithm for Feynman integrals ......................................................18 II.A.9. Non-abelian QHS algorithms -- A...idea is that NOT all environmentally entangling transformations are equally likely. In particular, for spatially separated physical quantum
Kleinberg, Jon
2006-01-01
Algorithm Design introduces algorithms by looking at the real-world problems that motivate them. The book teaches students a range of design and analysis techniques for problems that arise in computing applications. The text encourages an understanding of the algorithm design process and an appreciation of the role of algorithms in the broader field of computer science.
Wang, Lui; Bayer, Steven E.
1991-01-01
Genetic algorithms are mathematical, highly parallel, adaptive search procedures (i.e., problem solving methods) based loosely on the processes of natural genetics and Darwinian survival of the fittest. Basic genetic algorithms concepts are introduced, genetic algorithm applications are introduced, and results are presented from a project to develop a software tool that will enable the widespread use of genetic algorithm technology.
孟安波; 卢海明; 郭壮志
2016-01-01
Optimized the FCM clustering by the proposed CSO ( CSO-FCM) is introduced to diagnose the fault of transformer in order to conquer the shortages of FCM clustering.The combination of dissolved gas analysis and FCM clustering is effective on improving the accuracy rate of power transformer fault diagnosis, but the result of FCM cluste-ring is unstable and easy getting stuck in a local optimum.The CSO algorithm includes horizon cross as well as verti-cal cross, whose combining can enhance the global convergent ability while the introduction of competitive mechanism drives the potential solutions approximate the global optima in an accelerating fashion without sacrificing the conver-gence speed.This novel method effectively compensates the demerits of single intelligent algorithm, which not only has the ability to dispose the unstable information of fuzzy theory, also has an advantage of global convergence of CSO. Simulation and case analysis indicate that, compared with the traditional FCM clustering, the CSO-FCM clustering can obtain high performance clustering center and effectively raise the accuracy and diagnosis speed of power transformer fault diagnosis.%针对FCM（模糊C－均值聚类）在变压器故障诊断中的不足，提出采用纵横交叉算法优化FCM （ CSO－FCM）聚类来进行故障诊断。溶解气体分析与FCM相结合，能有效提高变压器故障诊断的准确率，但FCM存在聚类结果不稳定和容易陷入局部最优等问题。而纵横交叉算法是一种基于种群的随机搜索算法，在算法中首次提出了维局部最优概念和纵横交叉双搜索思想。实验证明，相比其它主流群智能优化算法，CSO算法在解决维数灾问题和收敛精度问题方面取得了较大突破，能有效克服局部最优的问题。新诊断模型有效弥补了单一诊断法的不足，拥有全局收敛性强和处理模糊信息的能力。实例分析表明，该方法与传统FCM相比，能获得
Power Efficient Hierarchical Scheduling for DSP Transformations
P. K. Merakos
2002-01-01
Full Text Available In this paper, the problem of scheduling the computation of partial products in transformational Digital Signal Processing (DSP algorithms, aiming at the minimization of the switching activity in data and address buses, is addressed. The problem is stated as a hierarchical scheduling problem. Two different optimization algorithms, which are based on the Travelling Salesman Problem (TSP, are defined. The proposed optimization algorithms are independent on the target architecture and can be adapted to take into account it. Experimental results obtained from the application of the proposed algorithms in various widely used DSP transformations, like Discrete Cosine Transform (DCT and Discrete Fourier Transform (DFT, show that significant switching activity savings in data and address buses can be achieved, resulting in corresponding power savings. In addition, the differences between the two proposed methods are underlined, providing envisage for their suitable selection for implementation, in particular transformational algorithms and architectures.
姚立健; 周高峰; 倪忠进; 张培培; 朱世威
2015-01-01
rotated at fixed interval 15° angle and the multi-view of fruit continuous images was achieved. Based on the analysis of fruit image color space, the fruits target and the background were divided by 2 R-G-B channels for removing image noise. The target image was proposed by gray histogram equalization; hence the image's contrast was enhanced. The pre-paired image had special information which could be used for extracting feature points. After comparing with speeded-up robust features (SURF) and scale invariant feature transform (SIFT) algorithm, image feature points were detected between two images using SIFT algorithm. The average number of characteristic vector with 128 dimensions for each image was 2500. Because of large quantity and high dimensions of characteristic vector, significant amount of time was consumed when using the traditionalK-D tree algorithm in searching matching points. To reduce the matching point of the existing area, a complete fruit image was divided into 16 regions, and four regions in the middle area with the most easily matching area for feature points were selected by multiple tests. A series of images collected by CCD camera only had lateral deviation between pre and post image. The searching scope of matching point was controlled in a narrow space between ±10 pixels through epipolar geometric constraint algorithm. Therefore, the mismatching rate was reduced and the images matching precision was improved. Finally, the mismatching points were rejected using the improved random sample consensus (RANSAC) algorithm, and it also could be further improved for matching precision. The initial translation matrix was obtained through rough matching points. The euclidean distance between pre and post image matching points selected randomly by using RANSAC was calculated. It was helpful to distinguish the interior point and exterior point. The final precisely matching points for each image were obtained based on presupposition threshold condition and
王海波; 周浩; 柳宁
2015-01-01
The Mark points detecting circle location technology is widely used in the industry application of printing, the electronic manufacturing,the Laser machining and so on. Manufacturing cost would be increased if only rising the printing quality of the mark points circle . The precision of detecting circle location can be improved by using the algorithm which eliminating effects on mark points circle edge defectives and circle lacks. After the mark points circle edge extracting,using the Radon transform employed to transmute the circle f (x,y ) to f (ρ,θ) , finding the peak point at the every and compare this point value with the corresponding value of the standard circle,judge the point is or not noise by the value difference large then a threshold value or not. Then use minimal two remaining method fit the real circle edge points. The experiments prove that the improvement vision circle location algorithm has more location precision and stability.%Mark点的圆定位技术在印刷、电子制造、激光加工等行业有着广泛的应用。为提高定位精度而一味地提高Mark点的印刷质量会带来成本的上升，通过算法改进消除Mark点边缘瑕疵和圆缺省的影响，可以提高定位精度。在提取Mark点圆图像的边缘后，采用Radon变换将定位圆 f (x,y )变换到 f (ρ,θ)，通过抽取每一θ角上的ρ的最值，并与标准圆对应的最值比较，按一个设定的阀值判定是否噪声，从而区分定位圆的真实边缘点和噪声，再通过最小二剩法对真实边缘点拟合求出圆心。实验证明，本改进方法针对有缺陷的定位圆有较高的定位精度与计算稳定性。
基于小波变换和时域波形的基音检测算法%Pitch Detection Algorithm Based on Wavelet Transform and Waveform in Time Domain
陈小利; 徐金甫
2011-01-01
An algorithm is proposed on the basis of wavelet transform and waveform in time domain to improve the accuracy of pitch detection.The pitch period of clear speech and noisy speech in different signal-to-noise ratio is detected by using the proposed method and the traditional methods of autocorrelation function and average magnitude difference function.The experiments show that the half frequency errors may occur in the method of autocorrelation function and double frequency errors may occur in the method of average magnitude difference function.Furthermore, the error frames of the two methods increase with the decrease of signal-to-noise ratio.In the proposed algorithm, there are relatively few double and half frequency errors, and the pitch contour is clear and smooth without big jump.The results are coincident with the common rule as the slow variation with time of speech signal.Therefpre, the accuracy of pitch detection can be improved effectively by the algo rithm.%为了准确地检测语音信号的基音周期,采用小波变换和时域波形相结合的方法,分别用传统的自相关法、平均幅度差法及文中算法对纯净语音和不同信噪比时的含噪语音进行基音检测.实验表明,自相关法易出现半频错误,平均幅度差法易出现倍频错误,且两者随着信噪比的降低,错误帧数呈增加趋势.然而文中算法倍频、半频错误相对较少,基音轮廓清晰、平滑,无大的跳变,符合语音信号慢时变性的一般规律,从而提高了基音检测的精度.
冉金和; 李修和
2014-01-01
A two-dimensional Chirp-Z Transform (CZT) imaging algorithm for general bistatic high squint SAR is proposed. To deal with the serious range-azimuth cross coupling of echo signal in bistatic high squint SAR, Linear Range Walk Correction (LRWC) is performed in range frequency-azimuth time domain to correct the large LRW induced by the high squint model of platforms, and then the expression of a modified bistatic point target reference spectrum is derived. Reference Function Multiplication (RFM) is firstly performed to finish the bulk focusing. With the track decoupling formulas, phase terms of spectrum are decomposed into two independent phase terms as range-variant phase terms and azimuth-variant phase terms, and their space variances are eliminated by CZT respectively to get the focusing result. The simulation tests validate the effectiveness of the proposed imaging algorithm to focus the data of general airborne bistatic high squint SAR.%该文提出一般构型机载双站大斜视SAR的2维Chirp-Z变换(CZT)成像算法。针对双站大斜视回波信号的距离-方位向强耦合，在距离频域-方位时域校正载机大斜视引起的大距离走动，然后推导改进点目标的频谱公式。成像时，先用参考函数相乘完成回波一致聚焦，然后借助于载机轨迹解耦合公式将频谱相位分解为距离移变和方位移变的两个独立相位项，再运用CZT分别消除其空变性得到成像结果。仿真验证了该算法处理一般构型机载双站大斜视SAR回波数据的有效性。
Joux, Antoine
2009-01-01
Illustrating the power of algorithms, Algorithmic Cryptanalysis describes algorithmic methods with cryptographically relevant examples. Focusing on both private- and public-key cryptographic algorithms, it presents each algorithm either as a textual description, in pseudo-code, or in a C code program.Divided into three parts, the book begins with a short introduction to cryptography and a background chapter on elementary number theory and algebra. It then moves on to algorithms, with each chapter in this section dedicated to a single topic and often illustrated with simple cryptographic applic
The fast wavelet X-ray transform
R.A. Zuidwijk; P.M. de Zeeuw (Paul)
1999-01-01
textabstractThe wavelet X-ray transform computes one-dimensional wavelet transforms along lines in Euclidian space in order to perform a directional time-scale analysis of functions in several variables. A fast algorithm is proposed which executes this transformation starting with values given on a
Quantum Central Processing Unit and Quantum Algorithm
王安民
2002-01-01
Based on a scalable and universal quantum network, quantum central processing unit, proposed in our previous paper [Chin. Phys. Left. 18 (2001)166], the whole quantum network for the known quantum algorithms,including quantum Fourier transformation, Shor's algorithm and Grover's algorithm, is obtained in a unitied way.
An algorithm for reduct cardinality minimization
AbouEisha, Hassan M.
2013-12-01
This is devoted to the consideration of a new algorithm for reduct cardinality minimization. This algorithm transforms the initial table to a decision table of a special kind, simplify this table, and use a dynamic programming algorithm to finish the construction of an optimal reduct. Results of computer experiments with decision tables from UCI ML Repository are discussed. © 2013 IEEE.
An algorithm for 3-SAT problems
Tsukimoto, Hiroshi
2016-01-01
This paper presents an algorithm for 3-SAT problems. First, logical formulas are transformed into elementary algebraic formulas. Second, complex trigonometric functions are assigned to the variables in the elementary algebraic formulas, and the sums of the formulas are calculated. The algorithm outputs the number of satisfying assignments. The computational complexity of the algorithm is probably polynomial.
黄臣; 田昕; 李涛; 田金文
2012-01-01
Low-complexity block-based Lapped Biorthogonal Transform which can effectively reduce blocking effect is applied in Joint Photographic Expert Group's newest standard for static image coding, whose most admirable advantage is the convenience of being implemented in hardware and its low complexity in both memory-occupying and time-consuming. To avoid its weakness in the disability of compression rate control, a resolution was given, after deeply researching into this new algorithm, the Bit Plate Encoding was used to substitute the original quantization process to achieve accurate rate-controlling.%双正交变换为基于块的低复杂度变换,而且与传统的离散余弦变换相比,一定程度上减小了变换后图像的块效应,因而被采纳入联合图像专家组织JPEG(Joint Photographic Expert Group)最新制定的静态图像编码标准JPEG XR中.为了能够改善其无法实现码流长度控制的缺陷,文章深入研究了JPEG XR的编码技术,提出了一种针对固定压缩比的编码算法.主要思路是通过对双正交变换后的系数进行嵌入式位平面编码,取代了原先的量化步骤,使得压缩码流长度可以精确控制.
熊坤来; 罗景青
2012-01-01
利用多相码雷达信号在某个分数阶域内呈现多个间隔相等的冲击这一特性,提出了一种基于分数阶Fourier变换的多相码雷达信号分离算法,首先将混合信号以特定的旋转角作分数阶Fourier变换,然后通过窄带通滤波器抽取多相码雷达信号,去除大量噪声和其他干扰信号,最后再经过分数阶Fourier反变换,恢复出时域的多相码雷达信号.理论分析和仿真实验表明,该算法计算量小,分离效果好,可实现较低信噪比下的多相码雷达信号分离.%By using the characteristics of poly-phase code radar signals that its energy are concentrated in one fractional domain, a separation algorithm of poly-phase code radar signals based on fractional Fourier transform (FrFT) is proposed in this paper. First, a mixed signal is rotated to a certain angle by the FrFT. Then, a narrow band filter is exploited to extract the poly-phase code radar signal and depress most of noise and other signals. Finally, the poly-phase code radar signal is rotated back to the time domain by the inverse FrFT. The theoretical analysis and simulation results demonstrate the validity of the method.
Generic Quantum Fourier Transforms
Moore, Cristopher; Russell, A; Moore, Cristopher; Rockmore, Daniel; Russell, Alexander
2003-01-01
The quantum Fourier transform (QFT) is the principal algorithmic tool underlying most efficient quantum algorithms. We present a generic framework for the construction of efficient quantum circuits for the QFT by ``quantizing'' the separation of variables technique that has been so successful in the study of classical Fourier transform computations. Specifically, this framework applies the existence of computable Bratteli diagrams, adapted factorizations, and Gel'fand-Tsetlin bases to offer efficient quantum circuits for the QFT over a wide variety a finite Abelian and non-Abelian groups, including all group families for which efficient QFTs are currently known and many new group families. Moreover, the method gives rise to the first subexponential-size quantum circuits for the QFT over the linear groups GL_k(q), SL_k(q), and the finite groups of Lie type, for any fixed prime power q.
Hougardy, Stefan
2016-01-01
Algorithms play an increasingly important role in nearly all fields of mathematics. This book allows readers to develop basic mathematical abilities, in particular those concerning the design and analysis of algorithms as well as their implementation. It presents not only fundamental algorithms like the sieve of Eratosthenes, the Euclidean algorithm, sorting algorithms, algorithms on graphs, and Gaussian elimination, but also discusses elementary data structures, basic graph theory, and numerical questions. In addition, it provides an introduction to programming and demonstrates in detail how to implement algorithms in C++. This textbook is suitable for students who are new to the subject and covers a basic mathematical lecture course, complementing traditional courses on analysis and linear algebra. Both authors have given this "Algorithmic Mathematics" course at the University of Bonn several times in recent years.
陈珂; 吴建平; 李金祥; 许旻; 鲜学丰; 顾才东
2015-01-01
The state of the art in circle detection usually resorts to edge pixels as the voting components to perform parametric accumulation in 2D or 3D space, which generally incurs high computational cost and is thus unable to meet the real-time processing requirements in complex natural scene processing. Using edge sections as voting components, this paper presents a robust real-time circle detection algorithm based on 1D probabilistic Hough Transform. The algorithm first segments Canny edges based on their gradient directions into arc sections, from which seed sections meeting certain curvature criteria are selected. For each seed, a probability-weighted 1D Hough accumulation is then built along the radius dimension to detect a valid circle related to the seed and estimate the initial radius of the circle based on the peak magnitude and peak position of the 1D accumulation. Finally direct circular least square fitting is employed to further pinpoint the radius and center information for the detected circle. The experiment shows, when appropriate segmentation thre-sholds are chosen, the algorithm significantly outperforms the state of the art in processing speed while maintaining high reliability as far as the circle detection in complex natural scene images is concerned.%针对现有圆检测算法以像素为投票主体在二维或三维空间进行参数累积，运算复杂度高，难以达到复杂自然场景中的实时检测要求的问题，提出一种以线段为投票主体并基于一维概率 Hough 变换的实时圆检测算法。首先基于梯度方向对 Canny 边缘像素实施逐段分割，从中选取满足一定曲率条件的线段作为种子，对每个种子沿半径进行一维概率 Hough 累积；然后根据峰值大小和位置提取有效圆及其初始半径；最后利用圆的直接最小二乘拟合进一步定位圆半径和圆心。对复杂的自然场景图像进行实验的结果表明，通过选取合适的分割阈值，该
Tel, G.
1993-01-01
We define the notion of total algorithms for networks of processes. A total algorithm enforces that a "decision" is taken by a subset of the processes, and that participation of all processes is required to reach this decision. Total algorithms are an important building block in the design of distri
Geometric constraint solving with geometric transformation
无
2001-01-01
This paper proposes two algorithms for solving geometric constraint systems. The first algorithm is for constrained systems without loops and has linear complexity. The second algorithm can solve constraint systems with loops. The latter algorithm is of quadratic complexity and is complete for constraint problems about simple polygons. The key to it is to combine the idea of graph based methods for geometric constraint solving and geometric transformations coming from rule-based methods.
SYMBOLIC VERSOR COMPRESSION ALGORITHM
Li Hongbo
2009-01-01
In an inner-product space, an invertible vector generates a reflection with re-spect to a hyperplane, and the Clifford product of several invertible vectors, called a versor in Clifford algebra, generates the composition of the corresponding reflections, which is an orthogonal transformation. Given a versor in a Clifford algebra, finding another sequence of invertible vectors of strictly shorter length but whose Clifford product still equals the input versor, is called versor compression. Geometrically, versor compression is equivalent to decomposing an orthogoual transformation into a shorter sequence of reflections. This paper proposes a simple algorithm of compressing versors of symbolic form in Clifford algebra. The algorithm is based on computing the intersections of lines with planes in the corresponding Grassmann-Cayley algebra, and is complete in the case of Euclidean or Minkowski inner-product space.
宋玉娥; 卜红霞; 杨洪涛; 王晓燕
2013-01-01
采用线性正则域模糊函数的二次调频(quadratic frequency modulated,QFM)信号参数估计算法简单易解,估计精度较高,误差传递小,在实际应用中有较好的前景.本文对输出信噪比进行了较为深入而详细的分析,推导了输出信噪比与输入信噪比及信号采样点数之间的关系表达式；通过仿真实验比较了在同等条件下和积分广义模糊函数算法(integrated generalized ambiguity function,IGAF)以及多项式相位变换(polynomial-phase transform,PPT)算法的输出信噪比大小,以及达到相同大小输出信噪比所需采样点数.发现该算法的输出信噪比要大于IGAF算法和PPT算法,且达到相同大小的输出信噪比所需采样点数分别是IGAF算法和PPT算法的1/4和1/9,即得到相同大小的输出信噪比时该算法所需的采样点数更少.%The parameter estimation algorithm for QFM signals using ambiguity function based on the linear canonical transform (LCTAF) is simple and has high estimation precision.Its error transfer is also small and has a good application prospect in the project.In this paper,the output signal-to-noise ratio (SNR) of this algorithm is analyzed deeply and derived the relationship between the output SNR and the number of sampling points and input SNR.By simulation experiments we compare the output SNR of LCTAF algorithm,with that of integrated generalized ambiguity function (IGAF) algorithm and polynomial-phase transform (PPT) algorithm under the same condition.And the required numbers of sampling points when the three algorithms achieve the same output SNR are also presented.We find out that the output SNR of our proposed algorithm is bigger than that of IGAF algorithm and PPT algorithm under the same simulation conditions.When achieving the same output SNR,the number of sampling points of LCTAF needed are 1/4 and 1/9 of the IGAF algorithm and the PPT algorithm needed,respectively.That is,the LCTAF algorithm needs fewer
Shift sampling theory of Fourier transform computation
柴玉璞
1997-01-01
The DFT transform us extended to DFTξη transform and the relationship between FT and DFTξη is given by the Fourier transform discretization theorem. Based on the theorem, the DFTξη algorithm-error equation (DFTξη A-E equation) is established, and the minimization property of discrete effect and the oscillation property of truncation effect are demonstrated. All these construct the shift sampling theory——a new theory about Fourier transform computation.
Agricultural image de-noising algorithm based on hybrid wavelet transform%基于杂交小波变换的农产品图像去噪算法
杨福增; 田艳娜; 杨亮亮; 何金伊
2011-01-01
The current image de-noising methods cannot remove the noise effectively, and they have the disadvantage of losing minutiae easily.A new de-noising method based on Hybrid Wavelet Transform was proposed in this study.Wavelet de-noising has the advantage of keeping the image's detail information, and Wiener Filter can obtain an optimal solution.This algorithm synthesized the advantages of Wavelet de-noising and Wiener Filter.Firstly, the image de-noised by Wavelet was used as male parent of the Hybrid Wavelet Transform's initial population, and image de-noised by Wiener Filter as female parent.Then, the individuals with fitness function of maximum between-cluster variance were evaluated.Through the hybrid and mutate operation, the gene recombination was realized, and then the superior gene of the two images de-noised was extracted by Wavelet and Wiener Filter.Finally, with the finite order hereditary algebra, an offspring image was obtained which has both advantages of male parent and female parent.The performance of this algorithm was tested by the red jujube images and wheat images.The results showed that images of red jujube and wheat de-noised by the proposed method had a higher PSNR (178.44 and 183.24) than those processed by conventional methodssuch as neighborhood average (176.76 and 175.16), median filter (174.79 and 173.13), Wiener filter (172.75 and 173.48) and Gauss filter (167.50 and 165.60) etc.The experimental results showed that the Hybrid Wavelet Transform de-noising method used on agricultural image had the advantage of high signal-to-noise ratio, and good visual effect.Therefore, the method proposed is effective and practicable.%针对现有图像去噪方法去噪效果不明显、易丢失细节特征等缺陷,提出了一种基于杂交小波变换的农产品图像去噪算法.该方法综合了小波去噪能较好保留图像细节特征和Wiener滤波器可得到最优解的优势,分别以经小波变换、Wiener滤波处理后的图像作
Face Recognition using Curvelet Transform
Cohen, Rami
2011-01-01
Face recognition has been studied extensively for more than 20 years now. Since the beginning of 90s the subject has became a major issue. This technology is used in many important real-world applications, such as video surveillance, smart cards, database security, internet and intranet access. This report reviews recent two algorithms for face recognition which take advantage of a relatively new multiscale geometric analysis tool - Curvelet transform, for facial processing and feature extraction. This transform proves to be efficient especially due to its good ability to detect curves and lines, which characterize the human's face. An algorithm which is based on the two algorithms mentioned above is proposed, and its performance is evaluated on three data bases of faces: AT&T (ORL), Essex Grimace and Georgia-Tech. k-nearest neighbour (k-NN) and Support vector machine (SVM) classifiers are used, along with Principal Component Analysis (PCA) for dimensionality reduction. This algorithm shows good results, ...
Agaian, Sos; Egiazarian, Karen; Astola, Jaakko
2011-01-01
The Hadamard matrix and Hadamard transform are fundamental problem-solving tools in a wide spectrum of scientific disciplines and technologies, such as communication systems, signal and image processing (signal representation, coding, filtering, recognition, and watermarking), digital logic (Boolean function analysis and synthesis), and fault-tolerant system design. Hadamard Transforms intends to bring together different topics concerning current developments in Hadamard matrices, transforms, and their applications. Each chapter begins with the basics of the theory, progresses to more advanced
杨晓慧; 焦李成
2008-01-01
Considering human visual system and characteristics of images, a novel image fusion strategy is presented ior panchromatic high resolution image and multispectral image in nonsubsampled contourlet transform (NSCT) domain. The NSCT can give an asymptotic optimal representation of edges and contours in image by virtue of its characteristics of good multiresolution, shiftinvariance, and high directionality. An intensity component addition strategy based on LHS transform is introduced into NSCT domain to preserve spatial resolution and color content. Experiments show that the fusion method proposed can improve spatial resolution and keep spectral information simultaneously, and that there are improvements both in visual effects and quantitative analysis compared with the traditional principle component analysis (PCA) method, intensity-hue-saturation (IHS) transform technique,wavelet transform weighted fusion method, corresponding wavelet transform-based fusion method, and contourlet transform-based fusion method.
A Short Survey of Document Structure Similarity Algorithms
Buttler, D
2004-02-27
This paper provides a brief survey of document structural similarity algorithms, including the optimal Tree Edit Distance algorithm and various approximation algorithms. The approximation algorithms include the simple weighted tag similarity algorithm, Fourier transforms of the structure, and a new application of the shingle technique to structural similarity. We show three surprising results. First, the Fourier transform technique proves to be the least accurate of any of approximation algorithms, while also being slowest. Second, optimal Tree Edit Distance algorithms may not be the best technique for clustering pages from different sites. Third, the simplest approximation to structure may be the most effective and efficient mechanism for many applications.
Discrete implementations of scale transform
Djurdjanovic, Dragan; Williams, William J.; Koh, Christopher K.
1999-11-01
Scale as a physical quantity is a recently developed concept. The scale transform can be viewed as a special case of the more general Mellin transform and its mathematical properties are very applicable in the analysis and interpretation of the signals subject to scale changes. A number of single-dimensional applications of scale concept have been made in speech analysis, processing of biological signals, machine vibration analysis and other areas. Recently, the scale transform was also applied in multi-dimensional signal processing and used for image filtering and denoising. Discrete implementation of the scale transform can be carried out using logarithmic sampling and the well-known fast Fourier transform. Nevertheless, in the case of the uniformly sampled signals, this implementation involves resampling. An algorithm not involving resampling of the uniformly sampled signals has been derived too. In this paper, a modification of the later algorithm for discrete implementation of the direct scale transform is presented. In addition, similar concept was used to improve a recently introduced discrete implementation of the inverse scale transform. Estimation of the absolute discretization errors showed that the modified algorithms have a desirable property of yielding a smaller region of possible error magnitudes. Experimental results are obtained using artificial signals as well as signals evoked from the temporomandibular joint. In addition, discrete implementations for the separable two-dimensional direct and inverse scale transforms are derived. Experiments with image restoration and scaling through two-dimensional scale domain using the novel implementation of the separable two-dimensional scale transform pair are presented.
A block Hankel generalized confluent Vandermonde matrix
Klein, A.; Spreij, P.
2014-01-01
Vandermonde matrices are well known. They have a number of interesting properties and play a role in (Lagrange) interpolation problems, partial fraction expansions, and finding solutions to linear ordinary differential equations, to mention just a few applications. Usually, one takes these matrices
A block Hankel generalized confluent Vandermonde matrix
Klein, A.; Spreij, P.
2014-01-01
Vandermonde matrices are well known. They have a number of interesting properties and play a role in (Lagrange) interpolation problems, partial fraction expansions, and finding solutions to linear ordinary differential equations, to mention just a few applications. Usually, one takes these matrices
Monad Transformers for Backtracking Search
Jules Hedges
2014-06-01
Full Text Available This paper extends Escardo and Oliva's selection monad to the selection monad transformer, a general monadic framework for expressing backtracking search algorithms in Haskell. The use of the closely related continuation monad transformer for similar purposes is also discussed, including an implementation of a DPLL-like SAT solver with no explicit recursion. Continuing a line of work exploring connections between selection functions and game theory, we use the selection monad transformer with the nondeterminism monad to obtain an intuitive notion of backward induction for a certain class of nondeterministic games.
Transforming Graph Representations for Statistical Relational Learning
Rossi, Ryan A; Aha, David W; Neville, Jennifer
2012-01-01
Relational data representations have become an increasingly important topic due to the recent proliferation of network datasets (e.g., social, biological, information networks) and a corresponding increase in the application of statistical relational learning (SRL) algorithms to these domains. In this article, we examine a range of representation issues for graph-based relational data. Since the choice of relational data representation for the nodes, links, and features can dramatically affect the capabilities of SRL algorithms, we survey approaches and opportunities for relational representation transformation designed to improve the performance of these algorithms. This leads us to introduce an intuitive taxonomy for data representation transformations in relational domains that incorporates link transformation and node transformation as symmetric representation tasks. In particular, the transformation tasks for both nodes and links include (i) predicting their existence, (ii) predicting their label or type...
Bhattacharya, Anjanabha; Kumar, Anish; Desai, Nirali; Parikh, Seema
2012-01-01
The source of genetic information in a plant cell is contained in nucleus, plastids, and mitochondria. Organelle transformation is getting a lot of attention nowadays because of its superior performance over the conventional and most commonly used nuclear transformation for obtaining transgenic lines. Absence of gene silencing, strong predictable transgene expression, and its application in molecular pharming, both in pharmaceutical and nutraceuticals, are some of many advantages. Other important benefits of utilizing this technology include the absence of transgene flow, as organelles are maternally inherited. This may increase the acceptability of organelle transformation technology in the development of transgenic crops in a wider scale all over the globe. As the need for crop productivity and therapeutic compounds increases, organelle transformation may be able to bridge the gap, thereby having a definite promise for the future.
Pedersen, Pia
2012-01-01
Transformation, defined as the step of extracting, arranging and simplifying data into visual form (M. Neurath, 1974), was developed in connection with ISOTYPE (International System Of TYpographic Picture Education) and might well be the most important legacy of Isotype to the field of graphic...... design. Recently transformation has attracted renewed interest because of the book ‘The Transformer’ written by Robin Kinross and Marie Neurath. My on-going research project, summarized in this paper, identifies and depicts the essential principles of data visualization underlying the process...... of transformation with reference to Marie Neurath’s sketches on the Bilston Project. The material has been collected at the Otto and Marie Neurath Collection housed at the University of Reading, UK. By using data visualization as a research method to look directly into the process of transformation the project...
Luzinski, Craig
2011-12-01
This month, the director of the Magnet Recognition Program® takes an in-depth look at the Magnet® model component transformational leadership. The author examines the expectations for Magnet organizations around this component. What are the qualities that make a nursing leader truly transformational, and what is the best approach to successfully lead a healthcare organization through today's volatile healthcare environment?
Munck Petersen, Rikke
2005-01-01
Seminaroplæg fra forskere. Faglige seminarer på KA, forår 2005. Belyser transformation af det danske landskab fysisk som holdningsmæssigt, samt hvordan phd-arbejdets egen proces håndterer den.......Seminaroplæg fra forskere. Faglige seminarer på KA, forår 2005. Belyser transformation af det danske landskab fysisk som holdningsmæssigt, samt hvordan phd-arbejdets egen proces håndterer den....
Hromkovic, Juraj
2009-01-01
Explores the science of computing. This book starts with the development of computer science, algorithms and programming, and then explains and shows how to exploit the concepts of infinity, computability, computational complexity, nondeterminism and randomness.
Listless zerotree image compression algorithm
Lian, Jing; Wang, Ke
2006-09-01
In this paper, an improved zerotree structure and a new coding procedure are adopted, which improve the reconstructed image qualities. Moreover, the lists in SPIHT are replaced by flag maps, and lifting scheme is adopted to realize wavelet transform, which lowers the memory requirements and speeds up the coding process. Experimental results show that the algorithm is more effective and efficient compared with SPIHT.
APPLICATION OF WAVELET TRANSFORM IN STRUCTURAL OPTIMIZATION
无
2001-01-01
It is very common in structural optimization that the optima lie at or in the vicinities of the singular points of feasible domain. Therefore it is very reasonable to introduce wavelet transform that is advantageous in singularity detection. The principle and algorithm of the application of wavelet transform in structural optimization are discussed The feasibility is demonstrated by some typical examples.
郑越; 杨淑莹
2012-01-01
This paper presents a new effective algorithm for monocular video stereoscopically transformation. With this algo-rithm, the monocular video can be transformed into stereoscopic format in nearly real time, and the output stream can be shown with lifelike three - dimensional effect on any supported display device. The core idea of this algorithm is to extract images from original monocular video, transform the images into stereoscopic ones according to Gaussian distribution, then build a three - level weighted average brightness map from the generated stereoscopic image sequences, correct the image regions respectively in all three level, and finally compose the complete three-dimensional video. After replacing the traditional time - consuming depth image generation algorithm with this one, the transformation performance obtains significantly improvement. Now the images with three - dimensional stereoscopic effect can be shown in real time during the original monocular video live broadcasts.%本文提出了一种新的平面视频转立体视频的快速算法.这种算法能够实时的将平面视频转换成立体视频,并能在三维显示设备上呈现出逼真的立体效果.首先将原始平面视频中的图像按照高斯分布进行立体变换,然后将视频中的图像序列生成加权平均亮度图,并将亮度分为3个等级,分别对这3个等级区域中的图像进行立体校正,最终得到完整的立体视频.我们的方法替代了传统方法中,生成深度图像的步骤,从而大大的提升了运算的速度,能够在原始平面视频的实时播放过程中,直接输出带有立体效果的画面.
The Performance Comparisons between the Unconstrained and Constrained Equalization Algorithms
HE Zhong-qiu; LI Dao-ben
2003-01-01
This paper proposes two unconstrained algorithms, the Steepest Decent (SD) algorithm and the Conjugate Gradient (CG) algorithm, based on a superexcellent cost function [1～3]. At the same time, two constrained algorithms which include the Constrained Steepest Decent (CSD) algorithm and the Constrained Conjugate Gradient algorithm (CCG) are deduced subject to a new constrain condition. They are both implemented in unitary transform domain. The computational complexities of the constrained algorithms are compared to those of the unconstrained algorithms. Resulting simulations show their performance comparisons.
Research on palmprint identification method based on quantum algorithms.
Li, Hui; Zhang, Zhanzhan
2014-01-01
Quantum image recognition is a technology by using quantum algorithm to process the image information. It can obtain better effect than classical algorithm. In this paper, four different quantum algorithms are used in the three stages of palmprint recognition. First, quantum adaptive median filtering algorithm is presented in palmprint filtering processing. Quantum filtering algorithm can get a better filtering result than classical algorithm through the comparison. Next, quantum Fourier transform (QFT) is used to extract pattern features by only one operation due to quantum parallelism. The proposed algorithm exhibits an exponential speed-up compared with discrete Fourier transform in the feature extraction. Finally, quantum set operations and Grover algorithm are used in palmprint matching. According to the experimental results, quantum algorithm only needs to apply square of N operations to find out the target palmprint, but the traditional method needs N times of calculation. At the same time, the matching accuracy of quantum algorithm is almost 100%.
Research on Palmprint Identification Method Based on Quantum Algorithms
Hui Li
2014-01-01
Full Text Available Quantum image recognition is a technology by using quantum algorithm to process the image information. It can obtain better effect than classical algorithm. In this paper, four different quantum algorithms are used in the three stages of palmprint recognition. First, quantum adaptive median filtering algorithm is presented in palmprint filtering processing. Quantum filtering algorithm can get a better filtering result than classical algorithm through the comparison. Next, quantum Fourier transform (QFT is used to extract pattern features by only one operation due to quantum parallelism. The proposed algorithm exhibits an exponential speed-up compared with discrete Fourier transform in the feature extraction. Finally, quantum set operations and Grover algorithm are used in palmprint matching. According to the experimental results, quantum algorithm only needs to apply square of N operations to find out the target palmprint, but the traditional method needs N times of calculation. At the same time, the matching accuracy of quantum algorithm is almost 100%.
A Sweepline Algorithm for Generalized Delaunay Triangulations
Skyum, Sven
We give a deterministic O(n log n) sweepline algorithm to construct the generalized Voronoi diagram for n points in the plane or rather its dual the generalized Delaunay triangulation. The algorithm uses no transformations and it is developed solely from the sweepline paradigm together...
Unconventional Algorithms: Complementarity of Axiomatics and Construction
Gordana Dodig Crnkovic
2012-10-01
Full Text Available In this paper, we analyze axiomatic and constructive issues of unconventional computations from a methodological and philosophical point of view. We explain how the new models of algorithms and unconventional computations change the algorithmic universe, making it open and allowing increased flexibility and expressive power that augment creativity. At the same time, the greater power of new types of algorithms also results in the greater complexity of the algorithmic universe, transforming it into the algorithmic multiverse and demanding new tools for its study. That is why we analyze new powerful tools brought forth by local mathematics, local logics, logical varieties and the axiomatic theory of algorithms, automata and computation. We demonstrate how these new tools allow efficient navigation in the algorithmic multiverse. Further work includes study of natural computation by unconventional algorithms and constructive approaches.
Spectral Transforms Calculation through Decision Diagrams
Radomir S. Stanković
2002-01-01
Full Text Available In this paper, calculation of spectral transforms through Decision diagrams (DDs and relationship of this method with FFT-like algorithms is discussed. It is shown that in DDs methods the basic operations in FFT-like algorithms are performed not on vectors but instead on parts of DDs as a data structure. Such a data structure represents the input signals, the intermediate results obtained during the calculation as well as the final output results. It should be noticed that, unlike FFT-like algorithms, DDs methods permit to take advantages from both, the properties of the transform matrices and the particular properties of the processed signals.
Positive automorphisms for self-induced interval exchange transformations
Jullian, Yann
2011-01-01
We give an algorithm to determine if the dynamical system generated by a positive automorphism of the free group can also be generated by a self-induced interval exchange transformation. The algorithm effectively yields the interval exchange transformation in case of success.
An Incremental Approach to Automatic Algorithm Design
LUAN Shangmin; LI Wei
1999-01-01
This paper presents an incrementalapproach to automatic algorithm design, which can be described byalgebraic specifications precisely and conveniently. The definitions ofselection operator and extension operator which can be defined bystrategy relations and transformations are given in order to model theprocess of finding the solution of a problem. Also discussed is itsobject-oriented implementation. The functional specification and thedesign specification for an algorithm are given in one framework so thatthe correctness of the algorithm can be easily proved.
WCTFR : WRAPPING CURVELET TRANSFORM BASED FACE RECOGNITION
Arunalatha J S
2015-03-01
Full Text Available The recognition of a person based on biological features are efficient compared with traditional knowledge based recognition system. In this paper we propose Wrapping Curvelet Transform based Face Recognition (WCTFR. The Wrapping Curvelet Transform (WCT is applied on face images of database and test images to derive coefficients. The obtained coefficient matrix is rearranged to form WCT features of each image. The test image WCT features are compared with database images using Euclidean Distance (ED to compute Equal Error Rate (EER and True Success Rate (TSR. The proposed algorithm with WCT performs better than Curvelet Transform algorithms used in [1], [10] and [11].
Neergaard, Helle; Robinson, Sarah; Jones, Sally
This paper develops the concept of ‘pedagogical nudging’ and examines four interventions in an entrepreneurship classroom and the potential it has for student identity transformation. Pedagogical nudging is positioned as a tool, which in the hands of a reflective, professional, with an understand......This paper develops the concept of ‘pedagogical nudging’ and examines four interventions in an entrepreneurship classroom and the potential it has for student identity transformation. Pedagogical nudging is positioned as a tool, which in the hands of a reflective, professional......, as well as the resources they have when they come to the classroom. It also incorporates perspectives from (ii) transformational learning and explores the concept of (iii) nudging from a pedagogical viewpoint, proposing it as an important tool in entrepreneurship education. The study incorporates......) assists students in straddling the divide between identities, the emotions and tensions this elicits, and (iv) transform student understanding. We extend nudging theory into a new territory. Pedagogical nudging techniques may be able to unlock doors and bring our students beyond the unacknowledged...
Andersen, Nicolai Bo
, that it can be adapted to changing functional needs, and that it has an architectural and cultural value. A specific proposal for a transformation that enhances the architectural qualities and building heritage values of an existing building forms the empirical material, which is discussed using different...