نتایج جستجو برای: transform domain

تعداد نتایج: 509603  

M.R Bahrami S Hatami,

In the present study, a spectral finite element method is developed for free and forced transverse vibration of Levy-type moderately thick rectangular orthotropic plates based on first-order shear deformation theory. Levy solution assumption was used to convert the two-dimensional problem into a one-dimensional problem. In the first step, the governing out-of-plane differential equations are tr...

Journal: :فیزیک زمین و فضا 0
محمدعلی ریاحی مؤسسه ژئوفیزیک دانشگاه تهران، دانشیار ناصر بنی حسن آی اف ام- ژئومار- کیل- آلمان- دانشجوی دکتری نوید امینی مؤسسه ژئوفیزیک دانشگاه تهران- دانشجوی دکتری

due to some difficulties during seismic data acquisition, like natural obstacles (high voltage electricity cable, bad coupling of geophones with the ground) some of the traces cannot be recorded. since bad traces make the final stack unclear, usually bad traces go mute while processing. the final image of the earth’s crust is highly dependent of the quality and resolution of acquired data and m...

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 ...

2014
Sangeeta Sharma Deepak Gupta V K Gupta Mahesh Chandra

In this paper, transform domain adaptive filters are studied and reviewed based on previous researches. In transform domain adaptive filters orthogonality properties of transformation such as discrete cosine transform (DCT), discrete sine transform (DST), wavelet transform and discrete fourier transform (DFT) are used to achieve an improved convergence rate as compared to the time domain analys...

Journal: :CoRR 2015
Muhammad Asad Khan Amir Ali Khan Fauzan Mirza

In cryptanalysis, security of ciphers vis-a-vis attacks is gauged against three criteria of complexities, i.e., computations, memory and time. Some features may not be so apparent in a particular domain, and their analysis in a transformed domain often reveals interesting patterns. Moreover, the complexity criteria in different domains are different and performance improvements are often achiev...

1991
Muralidhara Subbarao

A new linear transform is deened for real valued functions which can be expanded in Taylor series. For an image which can be expressed by the Taylor expansion of a function, the new transform corresponds to convolution of the image with a point spread function. The point spread function must satisfy the condition that it's zero-th moment is non-zero and positive integer moments are nite. The fo...

Journal: :IEEE Trans. Information Theory 1999
Guang Gong Solomon W. Golomb

DES can be regarded as a nonlinear feedback shift register (NLFSR) with input. From this point of view, the tools for pseudo-random sequence analysis are applied to the S-boxes in DES. The properties of the S-boxes of DES under Fourier transform, Hadamard transform, extended Hadamard transform and Avalanche transform are investigated. Two important results about the S-boxes of DES are found. Th...

Journal: :int. journal of mining & geo-engineering 2014
reza ahmadi nader fathianpour gholam-hossain norouzi

to date, a number of numerical methods, including the popular finite-difference time domain (fdtd) technique, have been proposed to simulate ground-penetrating radar (gpr) responses. despite having a number of advantages, the finite-difference method also has pitfalls such as being very time consuming in simulating the most common case of media with high dielectric permittivity, causing the for...

2013
Erik Rodner Judy Hoffman Jeff Donahue Trevor Darrell Kate Saenko

In this paper, we show how to learn transform-based domain adaptation classifiers in a scalable manner. The key idea is to exploit an implicit rank constraint, originated from a max-margin domain adaptation formulation, to make optimization tractable. Experiments show that the transformation between domains can be very efficiently learned from data and easily applied to new categories. Source c...

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