Colección de prácticas de tratamiento digital de audio para telecomunicaciones

Grado en Ingeniería de Sistemas Audiovisuales. Asignatura: Tratamiento digital de audio para Telecomunicacione

In-memory application-level checkpoint-based migration for MPI programs

This is a post-peer-review, pre-copyedit version of an article published in Journal of Supercomputing. The final authenticated version is available online at: https://doi.org/10.1007/s11227-014-1120-2[Abstract] Process migration provides many benefits for parallel environments including dynamic load balancing, data access locality or fault tolerance. This paper describes an in-memory application-level checkpoint-based migration solution for MPI codes that uses the Hierarchical Data Format 5 (HDF5) to write the checkpoint files. The main features of the proposed solution are transparency for the user, achieved through the use of CPPC (ComPiler for Portable Checkpointing); portability, as the application-level approach makes the solution adequate for any MPI implementation and operating system, and the use of the HDF5 file format enables the restart on different architectures; and high performance, by saving the checkpoint files to memory instead of to disk through the use of the HDF5 in-memory files. Experimental results prove that the in-memory approach reduces significantly the I/O cost of the migration process.Ministerio de Ciencia e Innovación; TIN2010-16735Galicia. Consellería de Economía e Industria; 10PXIB105180P

Failure Avoidance in MPI Applications Using an Application-Level Approach

[Abstract] Execution times of large-scale computational science and engineering parallel applications are usually longer than the mean-time-between-failures. For this reason, hardware failures must be tolerated by the applications to ensure that not all computation done is lost on machine failures. Checkpointing and rollback recovery is one of the most popular techniques to provide fault tolerance support to parallel applications. However, when a failure occurs, most checkpointing mechanisms require a complete restart of the parallel application from the last checkpoint. New advances in the prediction of hardware failures have led to the development of proactive process migration approaches, where tasks are migrated in a preventive way when node failures are anticipated, avoiding the restart of the whole application. The work presented in this paper extends an application-level checkpointing framework to proactively migrate message passing interface (MPI) processes when impending failures are notified, without having to restart the entire application. The main features of the proposed solution are: low overhead in failure-free executions, avoiding the checkpoint dumping associated to rolling back strategies; low overhead at migration time, by means of the design of a light and asynchronous protocol to achieve a consistent global state; transparency for the user, thanks to the use of a compiler tool and a runtime library and portability, as it is not locked into a particular architecture, operating system or MPI implementation.Ministerio de Ciencia e Innovación; TIN2010-16735Galicia. Consellería de Economía e Industria; 10PXIB105180P

Reducing the overhead of an MPI application-level migration approach

[Abstract] Process migration provides many benefits for parallel environments including dynamic load balance, data access locality, or fault tolerance. This work proposes a solution that reduces the memory and I/O overhead in an application-level checkpoint-based migration approach. The proposal splits the checkpoint files in order to overlap the writing of the state in the terminating processes with the read and restarting operation in the newly spawned processes. It has been tested using the MPI NAS Parallel Benchmarks, showing encouraging results, both in terms of memory consumption and I/O migration times.Ministerio de Economía y Competitividad; TIN2013-42148-PGalicia. Consellería de Cultura, Educación e Ordenación Universitaria; GRC2013/05

Gestión de servicio, instituciones educativas y calidad

El objetivo de este ensayo es evidenciar la importancia de la capacitación con visión integral del personal en las instituciones que incluyan administradores y directores, porque, estos actores deben ser generadores de cambio. En este sentido la formación de los funcionarios es primordial para que entiendan al servicio como un elemento diferenciador que asegura a las instituciones la permanencia y el crecimiento en el sector, así como la lealtad de sus colaboradores y de sus usuarios, ya que ellas hacen parte de un sistema social abierto, inmerso en un medio ambiente incierto y cambiante con el que se relaciona continuamente (Katz y Kahn, 1987). Por consiguiente, existen fuerzas ambientales que las afectan y a su vez éstas afectan el contorno

Sedimentación de plataforma interna-externa con desarrollo de montículos en el Viseense del sector central de la Sierra de la Estrella (Carbonífero, Córdoba)

En la Sierra de la Estrella (Área del Guadiato, Córdoba) se localiza una sucesión del Viseense superior, principalmente carbonatada, con desarrollo de montículos tipo mud-mound. En esta zona predominan calizas bioclásticas, brechoideas y bioconstruidas, aunque también se localizan niveles de areniscas y conglomerados. Se han identificado un total de 7 litofacies que agrupan a su vez a 9 microfacies tipo: 1.–Mudstonewackestone con cavidades estromatactoideas y fábricas fenestrales, 2.–Wackestonepackstone con algas y bioclastos, 3.1.–Packstone de pseudopeloides, 3.2.–Packstone con algas, pseudopeloides y litoclastos, 4.1.–Packstone de briozoos y crinoideos, 4.2.–Packstone con algas y espículas, 5.–Packstone-rudstone de litoclastos, 6.–Grainstone de cortoides y litoclastos, 7.–Arenitas híbridas. El ambiente de sedimentación se interpreta como una zona de transición entre rampa interna y externa carbonática con influencia de terrígenos y desarrollo de montículos microbianos. [ABSTRACT] Late Viséan calcareous rocks containing buildups occur in the Sierra de la Estrella, Guadiato Valley. Bioclastic, breccioid and biohermal limestones as well as sandstones and conglomerates occur. Lithofacies analysis allow to identify 7 types, with 9 characteristic microfacies: 1.–Micropeloidal mudstone-wackestone with stromatactoid cavities and fenestral fabrics, 2.–Algal-bioclastic wackestone-packstone, 3.1.–Pseudopeloidal packstone, 3.2.–Packstone with algae, pseudopeloids and lithoclast, 4.1.–Bryozoal-crinoidal packstone, 4.2.–Packstone with algae and sponge spiculae, 5.–Packstone-rudstone with lithoclasts, 6.–Cortoid-lithoclasts grainstone, 7.–Hybrid sandstones. Sediments are attributed to a inner to outer carbonate ramp with sporadic terrigenous influence. Some microbial mounds developed in such environment

A Rate Control Algorthm for Low-Delay H.264 Video Coding with Stored-B Pictures

A rate control (RC) algorithm for H.264 video coding with stored-B (SB) pictures is proposed for low-delay applications. Different models for P and SB pictures are defined for a better QP and MAD estimation. Furthermore, a novel saw-tooth shaped model of target buffer level has also been introduced for a proper bit allocation in GOP structures with SB pictures. Our experimental results show that this proposal outperforms the reference software RC in terms of buffer occupancy and target bit rate adjustment at the expense of slight quality reduction.Publicad

Ecological restoration research in Colombian Andean forests: a bibliometric analysis and information gap

Research is the basis for the development of ecological restoration strategies and therefore bears responsibility for the frequency of failure of this practice. Experimental research is considered one of the most powerful tools to establish the causality of an ecological phenomenon and to provide relevant information in terms of management of ecosystems. In this work, a review of the specific scientific knowledge on ecological restoration of Andean and high Andean forests was carried out, in order to perform an analysis based on bibliometric indicators of importance (Price Index, Isolation Index and Collaboration Index) and scientific impact (Immediacy Index and Impact Index of publications), and subsequently, to identify information gaps regarding experimental research. A total of 186 documents were analyzed, including scientific articles, technical papers, books, book sections and graduate theses. In general, experimental research in terms of ecological restoration in Andean and high Andean forests is only used in 17% of the research, with special emphasis on the study of flora. The largest information gaps, derived from experimental research, are found in the fields of agroecology, socioeconomics and multi-thematic or multidisciplinary studies. Most of the experimental investigations correspond to technical documents or degree thesis, with partial or unpublished results, so the potential for generating knowledge in ecological restoration is high, as long as the investigations are completed and carried out with sufficient scientific rigor

Aplicaciones con termografía infrarroja: caracterización de grietas verticales y medida de la difusividad térmica.

128 p.En este trabajo se presenta el uso de la termografía infrarroja para desarrollo de ensayos no destructivos enfocados a la detección y caracterización de grietas y la medida de la difusividad térmica de materiales en movimiento.La técnica de termografía modulada permite medir la resistencia térmica y caracterizar el ancho de la discontinuidad que se genera en la interfaz vertical entre dos materiales con diferentes propiedades térmicas, y la técnica de termografía de haz móvil, la cual permite caracterizar una grieta presente en un material que se mueve a velocidad constante.La caracterización de la difusividad térmica se realiza con termografía de haz móvil y es aplicada a una amplia variedad de materiales, desde aislantes térmicos hasta conductores térmicos de diferentes espesores que se mueven a velocidad constante. Todas estas propuestas experimentales fueron probadasen materiales calibrados obtenidos buenos resultados. Las técnicas propuestas en este trabajo pueden ser usadas en la inspección y control de calidad a nivel industrial