نتایج جستجو برای: Wavelet method

تعداد نتایج: 1655546  

Journal: :مرتع و آبخیزداری 0
پریوش طوفانی کارشناس ارشد مهندسی منابع آب دانشگاه علوم کشاورزی و منابع طبیعی گرگان احمد فاخری فرد استاد، گروه مهندسی آب دانشگاه تبریز ابوالفضل مساعدی استاد دانشکدة منابع طبیعی و محیط زیست دانشگاه فردوسی مشهد امیر احمد دهقانی دانشیار گروه مهندسی آب دانشگاه علوم کشاورزی و منابع طبیعی گرگان

prediction of precipitation is very important. regarding to the non- linear relationships and uncertainty of models, there is no superior and persuasive model among various proposed models to simulate precise precipitation and its amount. wavelet is one of the novel and very effective methods in time series and signals analyzing, that has been considered in the field of hydrology in recent year...

Journal: :computational methods for differential equations 0
chun-hui hsiao no.101, sec. 2, jhongcheng rd., shihlin district, taipei city 111, taiwan, r.o.c.

this paper presents a rational haar wavelet operational method for solving the inverse laplace transform problemand improves inherent errors from irrational haar wavelet. the approach is thus straightforward, rather simple andsuitable for computer programming. we define that $p$ is the operational matrix for integration of the orthogonalhaar wavelet. simultaneously, simplify the formulaes of li...

Journal: :فیزیک زمین و فضا 0
امین روشندل کاهو دانشجوی دکتری ژئوفیزیک، گروه فیزیک زمین، مؤسسة ژئوفیزیک دانشگاه تهران، ایران حمیدرضا سیاهکوهی دانشیار، گروه فیزیک زمین، مؤسسة ژئوفیزیک، دانشگاه تهران، ایران

in exploration seismology quality factor is widely used as a seismic attribute to identify anomalies related to attenuation, especially those caused by hydrocarbon. previous studies have indicated that seismic energy loss known as attenuation is greater for high frequency components of seismic data compared to the low frequency components. here the continuous wavelet transform is used to study ...

Journal: :Applied and Computational Harmonic Analysis 1999

, H. Homaei, H. Golestanian, M. Heidari,

This paper concentrates on a new procedure which experimentally recognises gears and bearings faults of a typical gearbox system using a least square support vector machine (LSSVM). Two wavelet selection criteria Maximum Energy to Shannon Entropy ratio and Maximum Relative Wavelet Energy are used and compared to select an appropriate wavelet for feature extraction. The fault diagnosis method co...

Removing noise from images is a challenging problem in digital image processing. This paper presents an image denoising method based on a maximum a posteriori (MAP) density function estimator, which is implemented in the wavelet domain because of its energy compaction property. The performance of the MAP estimator depends on the proposed model for noise-free wavelet coefficients. Thus in the wa...

2013
Daniel Alm Helmut Harbrecht Ulf Krämer

In the present paper, we introduce theH-wavelet method for the fast solution of nonlocal operator equations on unstructured meshes. On the given mesh, we construct a wavelet basis which provides vanishing moments with respect to the traces of polynomials in the space. With this basis at hand, the system matrix in wavelet coordinates is compressed to O(N logN) relevant matrix coefficients, where...

Journal: :journal of mahani mathematical research center 0

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ژورنال: پژوهش های ریاضی 2022

Wavelet analysis is one of the useful techniques in mathematics which is used much in statistics science recently. In this paper, in addition to introduce the wavelet transformation, the wavelet threshold estimation of semiparametric regression model with correlated errors with having Gaussian distribution is determined and the convergence ratio of estimator computed. To evaluate the wavelet th...

Journal: :journal of advances in computer research 2015
farima jafari reza javidan

this paper presents a new coding method for image compression based on jpeg2000 and contourlet transform. jpeg2000 standard is a common standard that uses discrete wavelet transform (dwt) in the compression process. the main problems of dwt are failure to detect curved edges in image and its shortage representation of the ridge and furrow patterns which cause deficiency and block artifacts rema...

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