Search results for "Computation"

Scalable Dense Factorizations for Heterogeneous Computational Clusters

2008

This paper discusses the design and the implementation of the LU factorization routines included in the Heterogeneous ScaLAPACK library, which is built on top of ScaLAPACK. These routines are used in the factorization and solution of a dense system of linear equations. They are implemented using optimized PBLAS, BLACS and BLAS libraries for heterogeneous computational clusters. We present the details of the implementation as well as performance results on a heterogeneous computing cluster.

DFT calculation of NMR δ(113Cd) in cadmium complexes

2016

Abstract We have tested several DFT protocols, at the non-relativistic and relativistic ZORA (scalar and spin–orbit) levels, for the calculation of the 113Cd chemical shifts, δ(113Cd), for a number of cadmium complexes accounting for both different local coordination environments on the metal center, involving N, O and S ligands, and different geometrical arrangements. Moreover, suitable models as reference compounds for δ(113Cd) evaluation have been set up in order to propose a complete computational approach to calculate δ(113Cd) for cadmium complexes. Inclusion of relativistic corrections did not lead to any sensible improvement in the quality of results and, in this context, non-relativ…

THE OPTIMAL SCALING OF A LINEAR RELUCTANCE MOTOR BY FIELD COMPUTATION

1995

The work aims at investigating the law of miniaturization of a linear reluctance motor by expressing the ratio of force to mass as a function of bar position in per unit, for different scale factors. Corresponding to the same factors, inductance is also computed. Finally the ratio of the bar length to external diameter is changed and the analysis is accordingly repeated.

Large-scale genome-wide association studies on a GPU cluster using a CUDA-accelerated PGAS programming model

2015

[Abstract] Detecting epistasis, such as 2-SNP interactions, in genome-wide association studies (GWAS) is an important but time consuming operation. Consequently, GPUs have already been used to accelerate these studies, reducing the runtime for moderately-sized datasets to less than 1 hour. However, single-GPU approaches cannot perform large-scale GWAS in reasonable time. In this work we present multiEpistSearch, a tool to detect epistasis that works on GPU clusters. While CUDA is used for parallelization within each GPU, the workload distribution among GPUs is performed with Unified Parallel C++ (UPC++), a novel extension of C++ that follows the Partitioned Global Address Space (PGAS) model…

Model-Based Evaluation of Methods for Respiratory Sinus Arrhythmia Estimation

2021

OBJECTIVE: Respiratory sinus arrhythmia (RSA) refers to heart rate oscillations synchronous with respiration, and it is one of the major representations of cardiorespiratory coupling. Its strength has been suggested as a biomarker to monitor different conditions, and diseases. Some approaches have been proposed to quantify the RSA, but it is unclear which one performs best in specific scenarios. The main objective of this study is to compare seven state-of-the-art methods for RSA quantification using data generated with a model proposed to simulate, and control the RSA. These methods are also compared, and evaluated on a real-life application, for their ability to capture changes in cardior…

Large-Scale Clustering of Short Reads for Metagenomics On GPUs

2013

Differential Evolution with Fitness Diversity Self-adaptation

2009

This chapter proposes the integration of fitness diversity adaptation techniques within the parameter setting of Differential Evolution (DE). The scale factor and crossover rate are encoded within each genotype and self-adaptively updated during the evolution by means of a probabilistic criterion which takes into account the diversity properties of the entire population. The population size is also adaptively controlled by means of a novel technique based on a measurement of the fitness diversity. An extensive experimental setup has been implemented by including multivariate problems and hard to solve fitness landscapes. A comparison of the performance has been conducted by considering both…

SCALING LAWS FOR THE LIFETIMES OF GOVERNMENTS IN THE SZNAJD DEMOCRACY

2005

We investigate the lifetimes of governments in the original and a randomized one-dimensional Sznajd model. We find various scaling laws for the lifetime of the democracy and for the reigning time of governments in this model, depending on the system size N.

Heavy-Flavor Contribution to Bhabha Scattering

2008

We evaluate the last missing piece of the two-loop QED corrections to the high-energy electron-positron scattering cross section originating from the vacuum polarization by heavy fermions. The calculation is performed within a new approach applicable to a wide class of perturbative problems with mass hierarchy. The result is crucial for the high-precision physics program at existing and future e(+) e(-) colliders.

Compressive imaging in scattering media.

2015

One challenge that has long held the attention of scientists is that of clearly seeing objects hidden by turbid media, as smoke, fog or biological tissue, which has major implications in fields such as remote sensing or early diagnosis of diseases. Here, we combine structured incoherent illumination and bucket detection for imaging an absorbing object completely embedded in a scattering medium. A sequence of low-intensity microstructured light patterns is launched onto the object, whose image is accurately reconstructed through the light fluctuations measured by a single-pixel detector. Our technique is noninvasive, does not require coherent sources, raster scanning nor time-gated detection…