Search results for "Computational Science"

Fast MATLAB assembly of FEM matrices in 2D and 3D: Edge elements

2014

We propose an effective and flexible way to assemble finite element stiffness and mass matrices in MATLAB. We apply this for problems discretized by edge finite elements. Typical edge finite elements are Raviart-Thomas elements used in discretizations of H(div) spaces and Nedelec elements in discretizations of H(curl) spaces. We explain vectorization ideas and comment on a freely available MATLAB code which is fast and scalable with respect to time.

Real-time computation of parameter fitting and image reconstruction using graphical processing units

2016

Abstract In recent years graphical processing units (GPUs) have become a powerful tool in scientific computing. Their potential to speed up highly parallel applications brings the power of high performance computing to a wider range of users. However, programming these devices and integrating their use in existing applications is still a challenging task. In this paper we examined the potential of GPUs for two different applications. The first application, created at Paul Scherrer Institut (PSI), is used for parameter fitting during data analysis of μ SR (muon spin rotation, relaxation and resonance) experiments. The second application, developed at ETH, is used for PET (Positron Emission T…

Elites, communities and the limited benefits of mentorship in electronic music

2020

AbstractWhile the emergence of success in creative professions, such as music, has been studied extensively, the link between individual success and collaboration is not yet fully uncovered. Here we aim to fill this gap by analyzing longitudinal data on the co-releasing and mentoring patterns of popular electronic music artists appearing in the annual Top 100 ranking of DJ Magazine. We find that while this ranking list of popularity publishes 100 names, only the top 20 is stable over time, showcasing a lock-in effect on the electronic music elite. Based on the temporal co-release network of top musicians, we extract a diverse community structure characterizing the electronic music industry.…

PANORMUS-SPH. A new Smoothed Particle Hydrodynamics solver for incompressible flows

2015

Abstract A new Smoothed Particle Hydrodynamics (SPH) solver is presented, fully integrated within the PANORMUS package [7] , originally developed as a Finite Volume Method (FVM) solver. The proposed model employs the fully Incompressible SPH approach, where a Fractional Step Method is used to make the numerical solution march in time. The main novelty of the proposed model is the use of a general and highly flexible procedure to account for different boundary conditions, based on the discretization of the boundary surfaces with a set of triangles and the introduction of mirror particles with suitable hydrodynamic properties. Both laminar and turbulent flows can be solved (the latter using t…

Efficient and portable acceleration of quantum chemical many-body methods in mixed floating point precision using OpenACC compiler directives

2016

It is demonstrated how the non-proprietary OpenACC standard of compiler directives may be used to compactly and efficiently accelerate the rate-determining steps of two of the most routinely applied many-body methods of electronic structure theory, namely the second-order M{\o}ller-Plesset (MP2) model in its resolution-of-the-identity (RI) approximated form and the (T) triples correction to the coupled cluster singles and doubles model (CCSD(T)). By means of compute directives as well as the use of optimized device math libraries, the operations involved in the energy kernels have been ported to graphics processing unit (GPU) accelerators, and the associated data transfers correspondingly o…

Computer-aided calculation of the molecular size of nondenatured proteins in pore-gradient gel electrophoresis

1991

A computer program written in Turbo C is described, which uses the two-step mathematical procedure published recently (Rothe, G. M., Electrophoresis 1988, 9, 307-316) to evaluate the molecular mass, Stokes' radius, spherical radius, and frictional coefficient of nondenatured proteins. The program runs on any IBM-PC or 100% compatible IBM-PC, provided the disk operating system MS-DOS or PC-DOS 3.0 or later has been installed. Functions that are permanently in use are accessible by menu. Storage and loading of data from disk and help instructions can be called by use of function keys. The program provides several tables into which inserted and calculated data is automatically integrated. Each…

A prospect for computing in porous materials research: Very large fluid flow simulations

2016

Abstract Properties of porous materials, abundant both in nature and industry, have broad influences on societies via, e.g. oil recovery, erosion, and propagation of pollutants. The internal structure of many porous materials involves multiple scales which hinders research on the relation between structure and transport properties: typically laboratory experiments cannot distinguish contributions from individual scales while computer simulations cannot capture multiple scales due to limited capabilities. Thus the question arises how large domain sizes can in fact be simulated with modern computers. This question is here addressed using a realistic test case; it is demonstrated that current …

A Novel Systolic Parallel Hardware Architecture for the FPGA Acceleration of Feedforward Neural Networks

2019

New chips for machine learning applications appear, they are tuned for a specific topology, being efficient by using highly parallel designs at the cost of high power or large complex devices. However, the computational demands of deep neural networks require flexible and efficient hardware architectures able to fit different applications, neural network types, number of inputs, outputs, layers, and units in each layer, making the migration from software to hardware easy. This paper describes novel hardware implementing any feedforward neural network (FFNN): multilayer perceptron, autoencoder, and logistic regression. The architecture admits an arbitrary input and output number, units in la…

The simulation library of the Belle II software system

2017

A framework for vertex reconstruction in the ATLAS experiment at LHC

2010

In anticipation of the first LHC data to come, a considerable effort has been devoted to ensure the efficient reconstruction of vertices in the ATLAS detector. This includes the reconstruction of photon conversions, long lived particles, secondary vertices in jets as well as finding and fitting of primary vertices. The implementation of the corresponding algorithms requires a modular design based on the use of abstract interfaces and a common Event Data Model. An enhanced software framework addressing various physics applications of vertex reconstruction has been developed in the ATLAS experiment. Presented in this paper are the general principles of this framework. A particular emphasis is…