检索结果-内蒙古大学图书馆

IEEE International Symposium on Geoscience and Remote Sensing (IGARSS)

作者： R. Gurcan I. Erer S. Kent Informatics Institute Advanced Technologies in Engineering Satellite Communication and Remote Sensing Program Istanbul Technical University Maslak Istanbul Turkey Istanbul Technical University Maslak Istanbul Turkey

Edges characterize boundaries and are therefore a problem of fundamental importance in image processing. Edge detecting an image significantly reduces the amount of data and filters out useless information, while preserving the important structural properties in an image. Edge detection is useful for segmentation, registration, and identification of objects in remote sensing images. Two dimensional lattice filters have been shown to be useful in many applications such as multidimensional spectral estimation, image data compression, high-resolution radar imaging, and removal of correlated clutter to enhance the detection ability of small objects in images. In this work, lattice filters are used for detecting the edges in remote sensing images. Lattice filter can be used to predict the correlated parts in an image and the resulting error (the output of the filter) will be edges. Edge detection results have been compared with other conventional edge detection methods as well as wavelet based methods. Results show that the proposed method is a good candidate for edge detection problem in remotely sensed images

关键词： Image edge detection Lattices Remote sensing Radar detection Image processing Information filtering Information filters Image segmentation Multidimensional systems Data compression

来源：评论

学校读者我要写书评

暂无评论

2-D orthogonal lattice filter based image segmentation

2-D orthogonal lattice filter based image segmentation

引用

IEEE International Symposium on Geoscience and Remote Sensing (IGARSS)

作者： S.Z. Aykut R. Gurcan I. Erer Istanbul Technical University Maslak Istanbul Turkey Informatics Institute Advanced Technologies in Engineering Satellite Communications and Remote Sensing Program Istanbul Technical University Maslak Istanbul Turkey

The purpose of image segmentation is to partition an image into homogeneous regions. Features are of major importance in image segmentation. In this work, a new method is proposed in which features used for segmentation are reflection coefficients of the two-dimensional (2D) orthogonal lattice filters. Principal component analysis (PCA) is applied to the features for reducing the complexity of the work. A minimum distance classifier is used in the classification algorithms. The proposed method is compared with the discrete wavelet transform which is a common segmentation algorithm. In our work, selected image is a monospectral optical image

关键词： Lattices Image segmentation Discrete wavelet transforms Optical filters Feature extraction Principal component analysis Remote sensing Optical reflection Filtering theory Predictive models

来源：评论

学校读者我要写书评

暂无评论

Weighted Eigenvalue Problem Approach To The Critical Value Determination Of Screened Coulomb Potential Systems

引用

Applied Numerical Analysis & Computational Mathematics 2004年第1期1卷

作者： Metin Demiralp Computational Science and Engineering Program Informatics Institute İstanbul Technical University Maslak 80626 İstanbul Turkey

In this work, the radial time-independent Schrödinger equation of a screened Coulomb potential system at the zero energy limit is first converted to a weighted eigenvalue problem of an ordinary differential operator. Then, by using an appropriate coordinate transformation, the differential equation is transformed into a form whose first and second order derivative related terms become same as the Extended Jacobi Polynomials' differential equation's corresponding terms. Only difference is the appearance of a multiplicative operator which can be considered as an effective potential. Work focuses on the point whether the solution is obtained easily depending on the structure of this potential. In this direction a screened Coulomb potential with a specific rational screening function is considered. The analytical solutions for the critical values of the screening parameter and the form of the wave function at the threshold of the continous spectrum are obtained. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

关键词： Screened Coulomb Potentials Extended Jacobi Polynomials Energy Spectrum

来源：评论

学校读者我要写书评

暂无评论

A Parametric Sensitivity Analysis for the Solution of Extrema Evaluation Problems via a Dimensionality Reducing Approximation Method

引用

Applied Numerical Analysis & Computational Mathematics 2004年第1期1卷

作者： Tülin Kaman Metin Demiralp Computational Science and Engineering Program Informatics Institute İstanbul Technical University Maslak 34469 İstanbul Turkey Phone: +90 212 285 70 82 Fax: +90 212 285 70 73

This work aims to apply High Dimensional Model Representation (HDMR) to the sensitivity coefficient determination of the solutions of a multivariate extrema problem. The derivations are made for general functional structure and the illustrative applications are related to structures where the resulting extrema equations are matrix eigenvalue problems. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

关键词： High Dimensional Model Representation Extrema Finding Matrix Inversion Matrix Eigenvalue

来源：评论

学校读者我要写书评

暂无评论

High Dimensional Model Representation Approximation of an Evolution Operator with a First Order Partial Differential Operator Argument

引用

Applied Numerical Analysis & Computational Mathematics 2004年第1期1卷

作者： İrem Yaman Metin Demiralp Computational Science and Engineering Program Informatics Institute İstanbul Technical University Maslak 34469 İstanbul Turkey Phone: +90 212 285 70 82 Fax: +90 212 285 70 73

In this work, a novel approximation scheme based on a recently developed representation, called the High Dimensional Model Representation (HDMR), is proposed to approximate evolution operators. The approximation is not developed at the operator level, instead the effect of the operator on an arbitrary function is approximated. The purpose of the work is to investigate how HDMR can be applied for the approximation of evolution operator and its efficiency. Although the approximation can be constructed for any order of multivariance, only the constant and univariate components of HDMR are considered in this work. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

关键词： Lie algebraic exponential operator High Dimensional Model Representation

来源：评论

学校读者我要写书评

暂无评论

Optimally Controlled Dynamics of One Dimensional Harmonic Oscillator: Linear Dipole Function and Quadratic Penalty

引用

Applied Numerical Analysis & Computational Mathematics 2004年第1期1卷

作者： Burcu Tunga Metin Demiralp Computational Science and Engineering Program Informatics Institute İstanbul Technical University Maslak 34469 İstanbul Turkey Phone: +90 212 285 70 82 Fax: +90 212 285 70 73

This work deals with the optimal control of one dimensional quantum harmonic oscillator under an external field characterized by a linear dipole function. The penalty term is taken as kinetic energy. The objective operator whose expectation value is desired to get a prescribed target value is taken as the square of the position operator. The dipole function hypothesis in the external field is valid only for weak fields otherwise hyperpolarizability terms which contain powers of the field amplitude higher than 1 should be considered. The weak field assumption enables us to develop a first order perturbation approach to get approximate solutions to the wave and costate equations. These solutions contain the field amplitude and another unknown, so-called deviation constant, through some certain integrals. By inserting these expressions into the connection equation which functionally relates the field amplitude to the wave and costate function it is possible to produce an integral equation. Same manipulations on the objective equation results in an algebraic equation to determine the deviation parameter. The algebraic deviation equation produces incompatibility which can be relaxed by including second order perturbative term of wave function. The integral and algebraic equations mentioned above are asymptotically solved. Their global solutions are left to future works since the main purpose of this work is to obtain the so-called field and deviation equations. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

关键词： Optimal control quantum mechanics harmonic oscillator weak field interaction perturbation

来源：评论

学校读者我要写书评

暂无评论

A Factorized High Dimensional Model Representation on the Partitioned Random Discrete Data

引用

Applied Numerical Analysis & Computational Mathematics 2004年第1期1卷

作者： M. Alper Tunga Metin Demiralp Department of Computer Science and Engineering Engineering Faculty Işįk University Maslak 34398 İstanbul Turkey Computational Science and Engineering Program Informatics Institute İstanbul Technical University Maslak 80626 İstanbul Turkey Phone: +90 212 285 70 82 Fax: +90 212 285 70 73

The main purpose of this work is to obtain the general structure of a product type of multivariate function when the values of the function are given randomly at the nodes of a hyperprism. When the dimensionality of multivariate interpolation and the number of the data sets increase unboundedly, many problems can be encountered in the standard numerical methods. Factorized High Dimensional Model Representation (FHDMR) is used to obtain the general structure of this given multivariate function. The components of FHDMR are determined by using the components of the Generalized High Dimensional Model Representation (GHDMR).The given random discrete data is partitioned by GHDMR method. This partitioned data produces a structure for the multivariate function by using single variable Lagrange interpolation formula including only the constant term and the univariate terms of the GHDMR components. Finally, a general structure is obtained via FHMDR by using these components. By this way, the multidimensionality of a multivariate interpolation is approximated by lower dimensional interpolations like univariate ones. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

关键词： Multivariate functions multivariate representations approximation factor analysis interpolation multidimensional problems

来源：评论

学校读者我要写书评

暂无评论

Optimal Control of One Dimensional Quantum Harmonic Oscillator Under an External Field With Quadratic Dipole Function and Penalty on Momentum: Construction of the Linearised Field Amplitude Integral Equation

引用

Applied Numerical Analysis & Computational Mathematics 2004年第1期1卷

作者： A. Kurşunlu İrem Yaman Metin Demiralp Computational Science and Engineering Program Informatics Institute İstanbul Technical University Maslak 34469 İstanbul Turkey Phone: +90 212 285 70 77 Fax: +90 212 285 70 73 Phone: +90 212 285 70 82 Fax: +90 212 285 70 73

In this work, the optimal control of an harmonic oscillator is considered. The external field is assumed to be weak and hence is represented by only dipole interaction. The dipole function is taken as a second degree polynomial in spatial coordinate. The objective term is composed of the expectation value of algebraic position operator. Penalty term related operator is taken as momentum. Some specific structures for spatial dependence is assumed and temporal equations are obtained for unknowns. The equations represent forward and backward evolution. The connection is provided by an algebraic equation coming from field amplitude related equation. The key unknown is the field amplitude since its determination leads us to evaluate all unknowns without remarkable difficulty. The purpose is not to determine field amplitude at the most general case but to construct an equation which involves this unknown only. The equation obtained via the linearisation of the field amplitude dependence is shown to be a linear integral equation. We do not attempt to solve it but discuss how to use appropriate methods for the solution. The equation is analytically solved at the zero interaction time limit. The real comprehensive implementation is left for future work. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

关键词： Optimal Control Quantum Mechanics Weak Field Interaction Perturbations Harmonic Oscillator

来源：评论

学校读者我要写书评

暂无评论

A parallel implementation of Chebyshev preconditioned conjugate gradient method

Bulletin of the Technical University of Istanbul

引用

Bulletin of the Technical University of Istanbul 2003年第2期53卷 13-21页

作者： Dag, Hasan Akcadogan, Cagatay Computational Science and Engineering Program Informatics Institute Istanbul Technical University 34469 Maslak Istanbul Turkey

A parallel implementation for linear set of equations of the form Ax = b is presented in this paper. In this implementation, instead of the traditional direct solution of Ax = b, conjugate gradient method is used. The conjugate gradient method is accelerated with an approximate inverse matrix preconditioner obtained from a linear combination of matrix-valued Chebyshev polynomials. This implementation is tested on a Sun SMP machine. Since conjugate gradient method and preconditioner contain mainly matrix-vector and matrix-matrix multiplications, convincing results are obtained in terms of both speed and scalability.

关键词： Chebyshev polynomials Conjugate gradient method Iterative methods Preconditioner

来源：评论

学校读者我要写书评

暂无评论

A parallel implementation of Chebyshev preconditioned conjugate gradient method

引用

ARI Bulletin of the Istanbul Technical University 2003年第2期53卷 13-21页

作者： Dag, Hasan Akcadogan, Cagatay Computational Science and Engineering Program Informatics Institute Istanbul Technical University 34469 Maslak Istanbul Turkey

关键词： Chebyshev polynomials Conjugate gradient method Iterative methods Preconditioner

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：