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If you brush against the wings of a butterfly, you will likely come away with a fine sprinkling of powder. This lepidopteran dust is made up of tiny microscopic scales, hundreds of thousands of which ...
Asian butterfly populations show different mimicry patterns,thanks to genetic 'switch'（图）
Asian butterfly populations different mimicry patterns genetic 'switch'
2021/1/28
A new study by researchers at the University of Chicago and the City College of New York has identified a unique, genetic "mimicry switch" that determines whether male and female Elymni...
Study reveals surprising amount of gene flow among butterfly species（图）
surprising amount gene flow among butterfly species
2019/11/15
Scientists know that shared parts of DNA create color patterns in some passion vine butterflies. The patterns help the butterflies ward off predators.Now a new study in Science provides evidence that ...
DNA links male,female butterfly thought to be distinct species（图）
DNA links male female butterfly distinct species
2017/9/1
Researchers recently discovered what was thought to be a distinct species of butterfly is actually the female of a species known to science for more than a century.An international team of nine butter...
Penn Collaboration Produces Surprising Insights Into the White Spots on Butterfly Wings
Penn Collaboration Insights White Spots Butterfly Wings
2017/7/24
A collaboration between biologists and materials scientists at the University of Pennsylvania is yielding new insights into the wings of the “skipper butterfly” in the Costa Rican rainforest. What the...
Scientists crack secrets of the monarch butterfly’s internal compass
Scientists monarch butterfly internal compass
2016/4/25
ach fall, monarch butterflies across Canada and the United States turn their orange, black and white-mottled wings toward the Rio Grande and migrate over 2,000 miles to the relative warmth of cen...
SPARSE FOURIER TRANSFORM VIA BUTTERFLY ALGORITHM
Fourier transform butterfly algorithm multiscale methods far field pattern
2015/7/14
This paper introduces a fast algorithm for computing sparse Fourier transforms with spatial and Fourier data supported on curves or surfaces. This problem appears naturally in several important applic...
A FAST BUTTERFLY ALGORITHM FOR THE COMPUTATION OF FOURIER INTEGRAL OPERATORS
Fourier integral operators butterfly algorithm dyadic partitioning Lagrange interpolation separated representation multiscale computations
2015/7/14
This paper is concerned with the fast computation of Fourier integral operators of the general form Rd e2πıΦ(x,k)f(k)dk, where k is a frequency variable, Φ(x, k) is a phase function obeying a st...
A Butterfly Algorithm for Synthetic Aperture Radar Imaging
fast algorithms low-rank expansions backprojection synthetic aperture radar
2015/7/14
In spite of an extensive literature on fast algorithms for synthetic aperture radar (SAR) imaging, it is not currently known if it is possible to accurately form an image from N data points in provabl...
A fast butterfly algorithm for generalized Radon transforms
fast butterfly algorithm generalized Radon transforms
2015/7/14
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. ...
A PARALLEL BUTTERFLY ALGORITHM
butterfly algorithm Egorov operator Radon transform parallel Blue Gene/Q
2015/7/14
The butterfly algorithm is a fast algorithm which approximately evaluates a discrete analogue of the integral transform Rd K(x, y)g(y)dy at large numbers of target points when the kernel, K(x, y), is...
A MULTISCALE BUTTERFLY ALGORITHM FOR MULTIDIMENSIONAL FOURIER INTEGRAL OPERATORS
Fourier integral operators the butterfly algorithm hierarchical decomposition separated representation
2015/7/14
This paper presents an efficient multiscale butterfly algorithm for computing Fourier integral operators (FIOs) of the form (Lf)(x) = Rd a(x, ξ)e2πıΦ(x,ξ)f (ξ)dξ, where Φ(x, ξ) is a phase funct...
BUTTERFLY FACTORIZATION
data-sparse matrix butterfly algorithm randomized algorithm matrix factorization operator compression Fourier integral operators special functions
2015/7/14
The paper introduces the butterfly factorization as a data-sparse approximation for the matrices that satisfy a complementary low-rank property. The factorization can be constructed efficiently if eit...
A Fast Butterfly Algorithm for the Computation of Fourier Integral Operators
Fourier integral operators the butterfly algorithm dyadic partitioning Lagrange interpolation separated representation multiscale computations
2015/6/17
This paper is concerned with the fast computation of Fourier integral operators of the general form RRd e2πıΦ(x,k)f(k)dk, where k is a frequency variable, Φ(x, k) is a phase function obeying a st...
Urbanization, higher temperatures can influence butterfly emergence patterns
Urbanization, higher temperatures can influence butterfly emergence patterns
2014/5/13
Urbanization and global climate change can profoundly alter biological systems, yet scientists often analyze their effects separately. We test how the timing of life cycle events (phenology) is jointl...