Improvements in the carbon dioxide and methane continuous measurement programs at Izaña Global GAW Station (Spain) during 2007-2009

Póster presentado en: 15th WMO/IAEA Meeting of Experts on Carbon Dioxide, Other Greenhouse Gases, and Related Tracer Measurement Techniques celebrado del 7 al 10 de septiembre de 2009 en Jena, Alemania.Continuous in-situ measurements of atmospheric CO2 and CH4 have been carried out at Izaña Global GAW station (Tenerife, Spain) since 1984. In the present report, we briefly summarize some improvements done in those programs during 2007-2009. Firstly, we deal with the CO2 program. In January 2007, we installed a new NDIR analyzer (Li-7000), which became our main CO2 analyzer. The instrumental system is briefly described, additionally to the acquisition/control software and raw data processing numerical code, which have been developed by us. Some details are provided about the processes used to transfer the WMO scale to the atmospheric CO2 measurements, together with the instrumental response function used, its determination and uncertainty. We perform an uncertainty propagation analysis, obtaining a standard uncertainty of 0.035 ppm for the consistency of our atmospheric CO2 measurements with the WMO-X2005 CO2 scale. Secondly, the CH4 program is considered. The new numerical codes developed by us to integrate peak area and to process calibrations are very briefly described. Finally, our intercomparison activities are mentioned

Evaluación del proyecto Newton. “Matemáticas para la Vida” de 3º a 6º de educación primaria

Se evalúa el impacto del “Proyecto Newton Matemáticas para la vida” en el profesorado y alumnado de 3º a 6º de Educación Primaria (Tenerife, España). Se constata el interés y el aprovechamiento que despierta la acción formativa en el profesorado. Para evaluar su impacto en el alumnado, se realiza un diseño trasversal y cuasiexperimental, con cuatro grupos: consolidado, cuatro años de participación en el Proyecto (N = 76), casi-consolidado, entre tres y dos años de participación (N = 210); de nueva incorporación (N = 63); y un grupo control (N = 89). Se detectan mejoras estadísticamente significativas, tanto en los procesos de resolución de problemas como en la adaptación escolar, en el alumnado cuyo profesorado participa en la formación. Estas mejoras se incrementan a medida que su profesorado lleva más tiempo implicado en el Proyecto

Design of efficient Java message-passing collectives on multi-core clusters

This is a post-peer-review, pre-copyedit version of an article published in The Journal of Supercomputing. The final authenticated version is available online at: https://doi.org/10.1007/s11227-010-0464-5[Abstract] This paper presents a scalable and efficient Message-Passing in Java (MPJ) collective communication library for parallel computing on multi-core architectures. The continuous increase in the number of cores per processor underscores the need for scalable parallel solutions. Moreover, current system deployments are usually multi-core clusters, a hybrid shared/distributed memory architecture which increases the complexity of communication protocols. Here, Java represents an attractive choice for the development of communication middleware for these systems, as it provides built-in networking and multithreading support. As the gap between Java and compiled languages performance has been narrowing for the last years, Java is an emerging option for High Performance Computing (HPC). Our MPJ collective communication library increases Java HPC applications performance on multi-core clusters: (1) providing multi-core aware collective primitives; (2) implementing several algorithms (up to six) per collective operation, whereas publicly available MPJ libraries are usually restricted to one algorithm; (3) analyzing the efficiency of thread-based collective operations; (4) selecting at runtime the most efficient algorithm depending on the specific multi-core system architecture, and the number of cores and message length involved in the collective operation; (5) supporting the automatic performance tuning of the collectives depending on the system and communication parameters; and (6) allowing its integration in any MPJ implementation as it is based on MPJ point-to-point primitives. A performance evaluation on an InfiniBand and Gigabit Ethernet multi-core cluster has shown that the implemented collectives significantly outperform the original ones, as well as higher speedups when analyzing the impact of their use on collective communications intensive Java HPC applications. Finally, the presented library has been successfully integrated in MPJ Express (http://mpj-express.org), and will be distributed with the next release.Ministerio de Ciencia e Innovación; TIN2010-16735Ministerio de Educación; FPU; AP2009-2112Xunta de Galicia; PGIDIT06PXIB105228P

Online signature verification systems on a low-cost FPGA

This paper describes three different approaches for the implementation of an online signature verification system on a low-cost FPGA. The system is based on an algorithm, which operates on real numbers using the double-precision floating-point IEEE 754 format. The doubleprecision computations are replaced by simpler formats, without affecting the biometrics performance, in order to permit efficient implementations on low-cost FPGA families. The first approach is an embedded system based on MicroBlaze, a 32-bit soft-core microprocessor designed for Xilinx FPGAs, which can be configured by including a single-precision floating-point unit (FPU). The second implementation attaches a hardware accelerator to the embedded system to reduce the execution time on floating-point vectors. The last approach is a custom computing system, which is built from a large set of arithmetic circuits that replace the floating-point data with a more efficient representation based on fixed-point format. The latter system provides a very high runtime acceleration factor at the expense of using a large number of FPGA resources, a complex development cycle and no flexibility since it cannot be adapted to other biometric algorithms. By contrast, the first system provides just the opposite features, while the second approach is a mixed solution between both of them. The experimental results show that both the hardware accelerator and the custom computing system reduce the execution time by a factor ×7.6 and ×201 but increase the logic FPGA resources by a factor ×2.3 and ×5.2, respectively, in comparison with the MicroBlaze embedded system.This research was funded by Spanish MCIN/AEI/10.13039/501100011033, grant number PID2019-107274RB-I00.Peer ReviewedPostprint (published version

Design of Scalable Java Communication Middleware for Multi-Core Systems

This is a post-peer-review, pre-copyedit version of an article published in The Computer Journal. The final authenticated version is available online at: https://doi.org/10.1093/comjnl/bxs122[Abstract] This paper presents smdev, a shared memory communication middleware for multi-core systems. smdev provides a simple and powerful messaging application program interface that is able to exploit the underlying multi-core architecture replacing inter-process and network-based communications by threads and shared memory transfers. The performance evaluation of smdev on several multi-core systems has shown noticeable improvements compared with other Java shared memory solutions, reaching and even overcoming the performance of natively compiled libraries. Thus, smdev has obtained start-up latencies around 0.76 μs and almost 90 Gbps bandwidth for point-to-point communications, as well as high performance and scalability both for collective operations and representative messaging kernels. This fact has motivated the integration of smdev in F-MPJ, our message-passing implementation in Java.Ministerio de Ciencia e Innovación; TIN2010-1673

Acceleration of Complex Algorithms on a Fast Reconfigurable Embedded System on Spartan-3

Complex algorithms usually require several computation stages. Many embedded microprocessors have not enough computational performance to resolve these algorithms in a reasonable time, so dedicated coprocessors accelerate them although the main drawback is the area devoted to them. A reconfigurable coprocessor can drastically reduce the area, since it accommodates a set of coprocessors whose execution is multiplexed on time, although the reconfiguration speed reduces the overall system performance. Although self-reconfigurable systems are possible on Spartan-3 FPGAs, it requires a hard design task due to the lack of software and hardware support available on higher-cost families. This paper describes the architecture of a fast self-reconfigurable embedded system mapped on Spartan-3, used as computation platform to solve a complex algorithm, such as the image-processing carried out in a fingerprint biometric algorithm. In order to reduce the reconfiguration time, the system uses our custom-made memory and reconfiguration controllers. Moreover, the dynamic coprocessor can access directly to external memory through our memory controller to improve processing time.Peer ReviewedPostprint (published version

FastMPJ: a scalable and efficient Java message-passing library

This is a post-peer-review, pre-copyedit version of an article published in Cluster Computing. The final authenticated version is available online at: http://dx.doi.org/https://doi.org/10.1007/s10586-014-0345-4[Abstract] The performance and scalability of communications are key for high performance computing (HPC) applications in the current multi-core era. Despite the significant benefits (e.g., productivity, portability, multithreading) of Java for parallel programming, its poor communications support has hindered its adoption in the HPC community. This paper presents FastMPJ, an efficient message-passing in Java (MPJ) library, boosting Java for HPC by: (1) providing high-performance shared memory communications using Java threads; (2) taking full advantage of high-speed cluster networks (e.g., InfiniBand) to provide low-latency and high bandwidth communications; (3) including a scalable collective library with topology aware primitives, automatically selected at runtime; (4) avoiding Java data buffering overheads through zero-copy protocols; and (5) implementing the most widely extended MPI-like Java bindings for a highly productive development. The comprehensive performance evaluation on representative testbeds (InfiniBand, 10 Gigabit Ethernet, Myrinet, and shared memory systems) has shown that FastMPJ communication primitives rival native MPI implementations, significantly improving the efficiency and scalability of Java HPC parallel applications.Ministerio de Educación y Ciencia; AP2010-4348Ministerio de Economía y Competitividad; TIN2010-16735Xunta de Galicia; CN2012/211Xunta de Galicia; GRC2013/05

Evaluation of messaging middleware for high-performance cloud computing

This is a post-peer-review, pre-copyedit version of an article published in Personal and Ubiquitous Computing. The final authenticated version is available online at: http://dx.doi.org/10.1007/s00779-012-0605-3[Abstract] Cloud computing is posing several challenges, such as security, fault tolerance, access interface singularity, and network constraints, both in terms of latency and bandwidth. In this scenario, the performance of communications depends both on the network fabric and its efficient support in virtualized environments, which ultimately determines the overall system performance. To solve the current network constraints in cloud services, their providers are deploying high-speed networks, such as 10 Gigabit Ethernet. This paper presents an evaluation of high-performance computing message-passing middleware on a cloud computing infrastructure, Amazon EC2 cluster compute instances, equipped with 10 Gigabit Ethernet. The analysis of the experimental results, confronted with a similar testbed, has shown the significant impact that virtualized environments still have on communication performance, which demands more efficient communication middleware support to get over the current cloud network limitations.Ministerio de Ciencia e Innovación; TIN2010-16735Ministerio de Educación y Ciencia; AP2010-434

25 years of continuous CO2 and CH4 measurements at Izaña Global GAW mountain station: annual cycles and interannual trends

Comunicación presentada en: Symposium on Atmospheric Chemistry and Physics at Mountain Sites (ACP Symposium) celebrado del 8 al 10 de junio de 2010 en Interlaken, Suiza

Silicon solar cell production line and key performance indicators: A case of study at front size serigraphy stage

Photovoltaic industry has devices power improvement as a main target. This implies that technological advances are continuously implemented in production lines and their power improvements have to be monitored with the suitable key performance indicators. In this work, front size serigraphy design has been selected as process improvement and laminated unit power and cell to module ratio has been defined as the main key performance indicator. Real size silicon PV cells with three different front finger morphologies have been produced in industrial production lines by the use of two front size serigraphy designs. The modification of the finger dimensions (wide/height) from (183.0 μm/31.6 μm) to (184.0 μm/37.6 μm) and (140.0 μm/40.8 μm) leads to a redistribution of the majority produced cell power range from [4.10–4.15) W to [4.10–4.15) W and [4.20–4.25) W respectively. Concerning the cell production, it has successfully been monitored by the laminated unit power indicator along a month when shows an increment from 3.95 W to 4.20 W. Concerning module level, cell to module ratio per process cell range is selected as suitable indicator and monitoring during a year. In the specific case of [4.30–4.35) W cell range, cell to module ratio decrease from 7.7 % to 6.5 %The authors are thankful to Erasmus+ Programme, SafeEngine project, contract no 2020-1-RO01-KA203-080085, Spanish Ministerio de Ciencia e Innovación through project PID2020-117832RB-100, UMA 18-FEDERJA-041 for their support and to Isofoton and J. Alcaide and J. Rando from 4TENERGY S.COOP:AND, for their collaboration. Funding for open access charge: Universidad de Málaga / CBU