3,121,556 research outputs found
TTC: A Tensor Transposition Compiler for Multiple Architectures
We consider the problem of transposing tensors of arbitrary dimension and
describe TTC, an open source domain-specific parallel compiler. TTC generates
optimized parallel C++/CUDA C code that achieves a significant fraction of the
system's peak memory bandwidth. TTC exhibits high performance across multiple
architectures, including modern AVX-based systems (e.g.,~Intel Haswell, AMD
Steamroller), Intel's Knights Corner as well as different CUDA-based GPUs such
as NVIDIA's Kepler and Maxwell architectures. We report speedups of TTC over a
meaningful baseline implementation generated by external C++ compilers; the
results suggest that a domain-specific compiler can outperform its general
purpose counterpart significantly: For instance, comparing with Intel's latest
C++ compiler on the Haswell and Knights Corner architecture, TTC yields
speedups of up to and , respectively. We also showcase
TTC's support for multiple leading dimensions, making it a suitable candidate
for the generation of performance-critical packing functions that are at the
core of the ubiquitous BLAS 3 routines
Comment on ``Sound velocity and multibranch Bogoliubov spectrum of an elongated Fermi superfluid in the BEC-BCS crossover"
The work by T. K. Ghosh and K. Machida [cond-mat/0510160 and Phys. Rev. A 73,
013613 (2006)] on the sound velocity in a cylindrically confined Fermi
superfluid obeying a power-law equation of state is shown to make use of an
improper projection of the sound wave equation. This inaccuracy fully accounts
for the difference between their results and those previously reported by
Capuzzi et al. [cond-mat/0509323 and Phys. Rev. A 73, 021603(R) (2006)]. In
this Comment we show that both approaches lead exactly to the same result when
the correct weight function is used in the projection. Plots of the correct
behavior of the phonon and monopole-mode spectra in the BCS, unitary, and BEC
limits are also shown.Comment: Comment on cond-mat/051016
Women-led Fisheries Management: A Case Study From Bangladesh
This is a case study of a women-led fishery in Bangladesh. Although women constitute 50% of the total population of Asia (Southern)-Bangladesh; only 18% are economically involved inthe total labor force. They are involved in diversified work within their homesteads. However, during times offamily needs and economic crisis, women are involved in non-traditional jobs. In the fisheries sector, Muslimwomen are traditionally not involved in fishing but they are involved in fish drying and salting. In the Hindudominated areas such as Goakhola-Hatiara, women are involved in fish catch as well as the collection of otheraquatic resources as one of their livelihood strategies. Women and subsistence fishers are taking the lead inmanaging a common capture fishery resource in Goakhola-Hatiara with the support from an NGO for perhapsthe first time in Bangladesh. However, the role of women in the Beel Management Committee is not well defined.Under the leadership of women the socio-economic conditions have changed and the social capital has increased
The dynamical equation of the spinning electron
We obtain by invariance arguments the relativistic and non-relativistic
invariant dynamical equations of a classical model of a spinning electron. We
apply the formalism to a particular classical model which satisfies Dirac's
equation when quantised. It is shown that the dynamics can be described in
terms of the evolution of the point charge which satisfies a fourth order
differential equation or, alternatively, as a system of second order
differential equations by describing the evolution of both the center of mass
and center of charge of the particle. As an application of the found dynamical
equations, the Coulomb interaction between two spinning electrons is
considered. We find from the classical viewpoint that these spinning electrons
can form bound states under suitable initial conditions. Since the classical
Coulomb interaction of two spinless point electrons does not allow for the
existence of bound states, it is the spin structure that gives rise to new
physical phenomena not described in the spinless case. Perhaps the paper may be
interesting from the mathematical point of view but not from the point of view
of physics.Comment: Latex2e, 14 pages, 5 figure
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