187 research outputs found
Desarrollo rural en el siglo XXI: Nuevas orientaciones y territorios
En reseña de:GÓMEZ ESPÍN, J. M.ª y MARTÍNEZ MEDINA, R. (2009). Desarrollo rural en el siglo XXI: Nuevas orientaciones y territorios. Universidad de Murcia. XIV Coloquio de Geografía Rural. 238 págs
NUEVOS DESARROLLOS URBANÍSTICOS EN EL CAMPO DE MURCIA. IMPLICACIONES TERRITORIALES Y PLANEAMIENTO MUNICIPAL
Since the late twentieth century, the town of Murcia has been experiencing a tremendous amount of large urban developments. While the urban core capital consolidates and extends its surrounding gardens, large housing developments associated peripheral or not golf courses, appearing on the periphery, witnessing new growth models dispersed and diffuse city. A new vision of the territory and a new model of socio-economic development at the dawn of the twenty-fi rst century, to bring the municipal area of Murcia important changes in land use and landscape. As a sign of this particular phenomenon in this paper will discuss some of the development projects that are giving rise to new residential areas south of the municipality Murcia, in the space traditionally known as «Field of Murcia.»Desde las postrimerías del siglo XX, el municipio de Murcia ha venido experimentando grandes desarrollos urbanísticos. Mientras el núcleo urbano capitalino se consolida y extiende por sus huertas aledañas, grandes urbanizaciones periféricas asociadas o no a campos de golf, aparecen en su periferia, atestiguando nuevos modelos de crecimiento disperso y ciudad difusa. Una nueva visión del territorio y un nuevo modelo de desarrollo socioeconómico que en los albores del siglo XXI, traen para el área municipal de Murcia cambios en los usos del suelo y el paisaje.
Como muestra de este particular fenómeno, en el presente trabajo se analizarán algunos de los proyectos urbanísticos que están dando lugar a nuevos espacios residenciales al Sur del término municipal, en la unidad espacial tradicionalmente conocida como «Campo de Murcia»
Energy‐aware strategies for task‐parallel sparse linear system solvers
This is the pre-peer reviewed version of the following article: Energy‐aware strategies for task‐parallel sparse linear system solvers, which has been published in final form at https://doi.org/10.1002/cpe.4633. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.We present several energy‐aware strategies to improve the energy efficiency of a task‐parallel preconditioned Conjugate Gradient (PCG) iterative solver on a Haswell‐EP Intel Xeon. These techniques leverage the power‐saving states of the processor, promoting the hardware into a more energy‐efficient C‐state and modifying the CPU frequency (P‐states of the processors) of some operations of the PCG. We demonstrate that the application of these strategies during the main operations of the iterative solver can reduce its energy consumption considerably, especially for memory‐bound computations
Characterization of Multicore Architectures using Task-Parallel ILU-type Preconditioned CG Solvers
Ponència presentada al 2nd Workshop on Power-Aware Computing (PACO 2017) Ringberg Castle, Germany, July, 5-8 2017We investigate the eficiency of state-of-the-art multicore processors using
a multi-threaded task-parallel implementation of the Conjugate Gradient
(CG) method, accelerated with an incomplete LU (ILU) preconditioner.
Concretely, we analyze multicore architectures with distinct
designs and market targets to compare their parallel performance and
energy eficiency
Harvesting Energy in ILUPACK via Slack Elimination
Ponència presentada al 2nd Workshop on Power-Aware Computing (PACO 2017) Ringberg Castle, Germany, July, 5-8 2017We develop a new energy-aware methodology to improve the energy
consumption of a task-parallel preconditioned Conjugate Gradient iter-
ative solver on a Haswell-EP Intel Xeon. This technique leverages the
power-saving modes of the processor and the frequency range of the
userspace Linux governor, modifying the CPU frequency for some oper-
ations. We demonstrate that its application during the main operations
of the PCG solver can reduce its energy consumption
Iteration-fusing conjugate gradient for sparse linear systems with MPI + OmpSs
In this paper, we target the parallel solution of sparse linear systems via iterative Krylov subspace-based method enhanced with a block-Jacobi preconditioner on a cluster of multicore processors. In order to tackle large-scale problems, we develop task-parallel implementations of the preconditioned conjugate gradient method that improve the interoperability between the message-passing interface and OmpSs programming models. Specifically, we progressively integrate several communication-reduction and iteration-fusing strategies into the initial code, obtaining more efficient versions of the method. For all these implementations, we analyze the communication patterns and perform a comparative analysis of their performance and scalability on a cluster consisting of 32 nodes with 24 cores each. The experimental analysis shows that the techniques described in the paper outperform the classical method by a margin that varies between 6 and 48%, depending on the evaluation
Dynamic spawning of MPI processes applied to malleability
Malleability allows computing facilities to adapt their workloads through resource management systems to maximize the throughput of the facility and the efficiency of the executed jobs. This technique is based on reconfiguring a job to a different resource amount during execution and then continuing with it. One of the stages of malleability is the dynamic spawning of processes in execution time, where different decisions in this stage will affect how the next stage of data redistribution is performed, which is the most time-consuming stage. This paper describes different methods and strategies, defining eight different alternatives to spawn processes dynamically and indicates which one should be used depending on whether a strong or weak scaling application is being used. In addition, it is described for both types of applications which strategies benefit most the application performance or the system productivity. The results show that reducing the number of spawning processes by reusing the older ones can reduce reconfiguration time compared to the classical method by up to 2.6 times for expanding and up to 36 times for shrinking. Furthermore, the asynchronous strategy requires analysing the impact of oversubscription on application performance.This work has been funded by the following projects: project PID2020-113656RB-C21 supported by MCIN/AEI/10.13039/501100011033 and project UJI-B2019-36 supported by UniversitatJaume I. Researcher S. Iserte was supported by the postdoctoralfellowship APOSTD/2020/026, and researcher I. Martín- Álvarez was supported by the predoctoral fellowship ACIF/2021/260, both
from Valencian Region Government and European Social Funds.Peer ReviewedPostprint (author's final draft
iMODS: internal coordinates normal mode analysis server
Normal mode analysis (NMA) in internal (dihedral) coordinates naturally reproduces the collective functional motions of biological macromolecules. iMODS facilitates the exploration of such modes and generates feasible transition pathways between two homologous structures, even with large macromolecules. The distinctive internal coordinate formulation improves the efficiency of NMA and extends its applicability while implicitly maintaining stereochemistry. Vibrational analysis, motion animationś and morphing trajectories can be easily carried out at different resolution scales almost interactively. The server is versatile; non-specialists can rapidly characterize potential conformational changes, whereas advanced users can customize the model resolution with multiple coarse-grained atomic representations and elastic network potentials. iMODS supports advanced visualization capabilities for illustrating collective motions, including an improved affine-model-based arrow representation of domain dynamics. The generated all-heavy-atoms conformations can be used to introduce flexibility for more advanced modeling or sampling strategies.Human Frontier Science Program—RGP0039/2008, Ministerio de Economía y Competitividad—BFU2013-44306P and Comunidad de Madrid—CAM-S2010/BMD
Insights from atomistic models on loop nucleation and growth in α-Fe thin films under Fe+ 100 keV irradiation
The question of how loops nucleate and grow in α-Fe under irradiation is addressed using object kinetic Monte Carlo with parameters from molecular dynamics and density functional theory calculations. Two models are considered for the formation of loops, both based on recent atomistic simulations. In one model loops are formed by the interaction between ½ loops. In a second model small interstitial clusters, nucleated in the collision cascade, can grow as or ½ loops. Comparing results from the calculations to experimental measurements of loop densities, ratios and sizes produced by Fe+ 100 keV irradiation of UHP Fe thin films at room temperature, the validity of the models is assessed. For these experimental conditions, the reaction model does not seem to be very efficient in the production of loops due to the fast recombination of ½ loops to surfaces. Therefore, in our thin film simulations (at very low carbon concentrations) most loops are a result of the nucleation model. In bulk simulations this effect could change since the probability of interactions between ½ loops would increase. Moreover, simulations show that total visible cluster concentration depends strongly on sample thickness and carbon content, while crystal orientation does not seem to have a significant role. Finally, the ratio of to ½ visible clusters changes with increased carbon concentration.This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014-2018 under grant agreement No 633053. The research leading to these results is partly funded by the European Atomic Energy Communitys (Euratom) Seventh Framework Programme FP7/2007e2013 under grant agreement No. 604862 (MatISSE project) and in the framework of the EERA (European Energy Research Alliance) Joint Programme on Nuclear Materials
Paralelización del calculo del numero pi utilizando librerías de precisión múltiple en un clúster de computadores
Ponència presentada en el XXXII Jornadas de Paralelismo (JP2022) y VI Jornadas de Computación Empotrada y Reconfigurable (JCER2022) SARTECO 2022La Computación de Altas Prestaciones
(CAP), o High Performance Computing (HPC), es un
campo de la Ingeniería Informática que tiene como
principal objetivo extraer el mejor rendimiento de los
recursos disponibles de un computador para la resolución de un problema informático. Alcanzar este objetivo requiere tener un conocimiento detallado de la
arquitectura y del sistema operativo, así como de los
algoritmos y los lenguajes de programación que permiten implementar códigos más eficientes.
En este artículo se presenta la evaluación de dos librerías de precisión múltiple para CPU y cómo éstas
se pueden utilizar en procesadores multinúcleo y en
multicomputadores o clusters de procesadores multinúcleo para el cálculo de la constante numérica π
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