164,915 research outputs found
Density Functional Theory calculation on many-cores hybrid CPU-GPU architectures
The implementation of a full electronic structure calculation code on a
hybrid parallel architecture with Graphic Processing Units (GPU) is presented.
The code which is on the basis of our implementation is a GNU-GPL code based on
Daubechies wavelets. It shows very good performances, systematic convergence
properties and an excellent efficiency on parallel computers. Our GPU-based
acceleration fully preserves all these properties. In particular, the code is
able to run on many cores which may or may not have a GPU associated. It is
thus able to run on parallel and massive parallel hybrid environment, also with
a non-homogeneous ratio CPU/GPU. With double precision calculations, we may
achieve considerable speedup, between a factor of 20 for some operations and a
factor of 6 for the whole DFT code.Comment: 14 pages, 8 figure
The Analogue Computer as a Voltage-Controlled Synthesiser
This paper re-appraises the role of analogue computers within electronic and
computer music and provides some pointers to future areas of research. It
begins by introducing the idea of analogue computing and placing in the context
of sound and music applications. This is followed by a brief examination of the
classic constituents of an analogue computer, contrasting these with the
typical modular voltage-controlled synthesiser. Two examples are presented,
leading to a discussion on some parallels between these two technologies. This
is followed by an examination of the current state-of-the-art in analogue
computation and its prospects for applications in computer and electronic
music
Parallel computing and the generation of basic plasma data
Comprehensive simulations of the processing plasmas used in semiconductor fabrication will depend on the availability of basic data for many microscopic processes that occur in the plasma and at the surface. Cross sections for electron collisions, a principal mechanism for producing reactive species in these plasmas, are among the most important such data; however, electron-collision cross sections are difficult to measure, and the available data are, at best, sketchy for the polyatomic feed gases of interest. While computational approaches to obtaining such data are thus potentially of significant value, studies of electron collisions with polyatomic gases at relevant energies are numerically intensive. In this article, we report on the progress we have made in exploiting large-scale distributed-memory parallel computers, consisting of hundreds of interconnected microprocessors, to generate electron-collision cross sections for gases of interest in plasma simulations
Memory and information processing in neuromorphic systems
A striking difference between brain-inspired neuromorphic processors and
current von Neumann processors architectures is the way in which memory and
processing is organized. As Information and Communication Technologies continue
to address the need for increased computational power through the increase of
cores within a digital processor, neuromorphic engineers and scientists can
complement this need by building processor architectures where memory is
distributed with the processing. In this paper we present a survey of
brain-inspired processor architectures that support models of cortical networks
and deep neural networks. These architectures range from serial clocked
implementations of multi-neuron systems to massively parallel asynchronous ones
and from purely digital systems to mixed analog/digital systems which implement
more biological-like models of neurons and synapses together with a suite of
adaptation and learning mechanisms analogous to the ones found in biological
nervous systems. We describe the advantages of the different approaches being
pursued and present the challenges that need to be addressed for building
artificial neural processing systems that can display the richness of behaviors
seen in biological systems.Comment: Submitted to Proceedings of IEEE, review of recently proposed
neuromorphic computing platforms and system
Count three for wear able computers
This paper is a postprint of a paper submitted to and accepted for publication in the Proceedings of the IEE Eurowearable 2003 Conference, and is subject to Institution of Engineering and Technology Copyright. The copy of record is available at the IET Digital Library.
A revised version of this paper was also published in Electronics Systems and Software, also subject to Institution of Engineering and Technology Copyright. The copy of record is also available at the IET Digital Library.A description of 'ubiquitous computer' is presented. Ubiquitous computers imply portable computers embedded into everyday objects, which would replace personal computers. Ubiquitous computers can be mapped into a three-tier scheme, differentiated by processor performance and flexibility of function. The power consumption of mobile devices is one of the most important design considerations. The size of a wearable system is often a design limitation
A Hybrid Decomposition Parallel Implementation of the Car-Parrinello Method
We have developed a flexible hybrid decomposition parallel implementation of
the first-principles molecular dynamics algorithm of Car and Parrinello. The
code allows the problem to be decomposed either spatially, over the electronic
orbitals, or any combination of the two. Performance statistics for 32, 64, 128
and 512 Si atom runs on the Touchstone Delta and Intel Paragon parallel
supercomputers and comparison with the performance of an optimized code running
the smaller systems on the Cray Y-MP and C90 are presented.Comment: Accepted by Computer Physics Communications, latex, 34 pages without
figures, 15 figures available in PostScript form via WWW at
http://www-theory.chem.washington.edu/~wiggs/hyb_figures.htm
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