A Highly Optimized Skeleton for Unbalanced and Deep Divide-And-Conquer Algorithms on Multi-Core Clusters

Financiado para publicación en acceso aberto: Universidade da Coruña/CISUG [Abstract] Efficiently implementing the divide-and-conquer pattern of parallelism in distributed memory systems is very relevant, given its ubiquity, and difficult, given its recursive nature and the need to exchange tasks and data among the processors. This task is noticeably further complicated in the presence of multi-core systems, where hybrid parallelism must be exploited to attain the best performance, and when unbalanced and deep workloads are considered, as additional measures must be taken to load balance and avoid deep recursion problems. In this manuscript a parallel skeleton that fulfills all these requirements while providing high levels of usability is presented. In fact, the evaluation shows that our proposal is on average 415.32% faster than MPI codes and 229.18% faster than MPI + OpenMP benchmarks, while offering an average improvement in the programmability metrics of 131.04% over MPI alternatives and 155.18% over MPI + OpenMP solutions.This research was supported by the Ministry of Science and Innovation of Spain (PID2019-104184RB-I00 and PID2019-104834GB-I00, AEI/FEDER/EU, 10.13039/501100011033) and the predoctoral Grant of Millán Álvarez Ref. BES-2017-081320), and by the Xunta de Galicia co-founded by the European Regional Development Fund (ERDF) under the Consolidation Programme of Competitive Reference Groups (ED431C 2018/19 and ED431C 2021/30). We acknowledge also the support from the Centro Singular de Investigación de Galicia “CITIC” and the Centro Singular de Investigación en Tecnoloxías Intelixentes “CiTIUS”, funded by Xunta de Galicia and the European Union (European Regional Development Fund- Galicia 2014-2020 Program), by Grants ED431G 2019/01 and ED431G 2019/04. We also acknowledge the Centro de Supercomputación de Galicia (CESGA). Open Access funding provided thanks to the CRUE-CSIC agreement with Springer NatureXunta de Galicia; ED431C 2018/19Xunta de Galicia; ED431C 2021/30Xunta de Galicia; ED431G 2019/01Xunta de Galicia; ED431G 2019/0

Empresas democráticas y éxito económico. El modelo cooperativo

We would like to thank RGEAF and ECOBAS of the University of Vigo for the support provided for carrying out our research work.This paper analyzes how co-operative principles, particularly democratic management, affect the co-op’s economic objective. The theoretical model specifies the characteristics presented by the production function so democracy generates positive net income. Costs derived from maintaining the one person one vote criterion are explicitly incorporated into this function upon new membership. The results show that democracy contributes to the economic success when the decision-making strategy followed by the partners considers all cooperative principles, especially when a retained earnings policy is regularly applied. This study can be extended to all of Social Economy firms concerned about reinforcing democratic institutions through the business sector. This study can be extended to all of Social Economy firms concerned about reinforcing democratic institutions through the business sector.Este artículo analiza cómo los principios cooperativos, particularmente la gestión democrática, afecta al objetivo económico de la cooperativa. El modelo teórico muestra qué características debe presentar la función de producción de la empresa para que la democracia genere ingresos netos positivos. Los costes derivados de aplicar el criterio de una persona, un voto, ante la entrada de nuevos socios, son explícitamente incorporados en esta función de producción. Los resultados muestran que la democracia contribuye al éxito económico cuando la estrategia de toma de decisiones aplicada por los socios respeta el conjunto de principios cooperativos, especialmente cuando se adopta habitualmente una política de excedente positivo. Este estudio puede extenderse a todas las empresas de Economía Social interesadas en reforzar las instituciones democráticas en la gestión empresarial.Escuela de Estudios CooperativosFac. de Ciencias Económicas y EmpresarialesTRUEpu

Empresas democráticas y éxito económico. El modelo cooperativo

This paper analyzes how co-operative principles, particularly democratic management, affect the co-op’s economic objective. The theoretical model specifies the characteristics presented by the production function so democracy generates positive net income. Costs derived from maintaining the one person one vote criterion are explicitly incorporated into this function upon new membership. The results show that democracy contributes to the economic success when the decision-making strategy followed by the partners considers all cooperative principles, especially when a retained earnings policy is regularly applied. This study can be extended to all of Social Economy firms concerned about reinforcing democratic institutions through the business sector. This study can be extended to all of Social Economy firms concerned about reinforcing democratic institutions through the business sector

Democratic firms and economic success. The co-op model

This paper analyzes how co-operative principles, particularly democratic management, affect the co-op’s economic objective. The theoretical model specifies the characteristics presented by the production function so democracy generates positive net income. Costs derived from maintaining the one person one vote criterion are explicitly incorporated into this function upon new membership. The results show that democracy contributes to the economic success when the decision-making strategy followed by the partners considers all cooperative principles, especially when a retained earnings policy is regularly applied. This study can be extended to all of Social Economy firms concerned about reinforcing democratic institutions through the business sector. This study can be extended to all of Social Economy firms concerned about reinforcing democratic institutions through the business sector

Anticipating the collapse of urban infrastructure: a methodology based on Earth Observation and MT-InSAR

Large-scale infrastructure monitoring and vulnerability assessment are crucial for the preservation and maintenance of built environments. To ensure the safety of urban infrastructure against natural and man-made disasters, constant monitoring is crucial. To do so, satellite Earth observation (EO) is being proposed, particularly radar-based imaging, because it allows large-scale constant monitoring since radar signals are not blocked by clouds and can be collected during both day and night. The proposed methodology for large-scale infrastructure monitoring and vulnerability assessment is based on MT-InSAR time series analysis. The homogeneity of the year-to-year displacement trend between each point and its surrounding points is evaluated to determine whether the area is a stable or vulnerable zone. To validate the methodology, four case studies of recently collapsed infrastructures are analyzed. The results indicate the potential of the proposed methodology for predicting and preventing structural collapses.Ministerio de Ciencia e Innovación | Ref. PID2021-124236OB-C3

Automatic Extraction of Road Points from Airborne LiDAR Based on Bidirectional Skewness Balancing

Road extraction from Light Detection and Ranging (LiDAR) has become a hot topic over recent years. Nevertheless, it is still challenging to perform this task in a fully automatic way. Experiments are often carried out over small datasets with a focus on urban areas and it is unclear how these methods perform in less urbanized sites. Furthermore, some methods require the manual input of critical parameters, such as an intensity threshold. Aiming to address these issues, this paper proposes a method for the automatic extraction of road points suitable for different landscapes. Road points are identified using pipeline filtering based on a set of constraints defined on the intensity, curvature, local density, and area. We focus especially on the intensity constraint, as it is the key factor to distinguish between road and ground points. The optimal intensity threshold is established automatically by an improved version of the skewness balancing algorithm. Evaluation was conducted on ten study sites with different degrees of urbanization. Road points were successfully extracted in all of them with an overall completeness of 93%, a correctness of 83%, and a quality of 78%. These results are competitive with the state-of-the-artThis work has received financial support from the Consellería de Cultura, Educación e Ordenación Universitaria (accreditation 2019-2022 ED431G-2019/04 and reference competitive group 2019-2021, ED431C 2018/19) and the European Regional Development Fund (ERDF), which acknowledges the CiTIUS-Research Center in Intelligent Technologies of the University of Santiago de Compostela as a Research Center of the Galician University System. This work was also supported in part by Babcock International Group PLC (Civil UAVs Initiative Fund of Xunta de Galicia) and the Ministry of Education, Culture and Sport, Government of Spain (Grant Number TIN2016-76373-P)S

Fast Ground Filtering of Airborne LiDAR Data Based on Iterative Scan-Line Spline Interpolation

Over the last two decades, a wide range of applications have been developed from Light Detection and Ranging (LiDAR) point clouds. Most LiDAR-derived products require the distinction between ground and non-ground points. Because of this, ground filtering its being one of the most studied topics in the literature and robust methods are nowadays available. However, these methods have been designed to work with offline data and they are generally not well suited for real-time scenarios. Aiming to address this issue, this paper proposes an efficient method for ground filtering of airborne LiDAR data based on scan-line processing. In our proposal, an iterative 1-D spline interpolation is performed in each scan line sequentially. The final spline knots of a scan line are taken into account for the next scan line, so that valuable 2-D information is also considered without compromising computational efficiency. Points are labelled into ground and non-ground by analysing their residuals to the final spline. When tested against synthetic ground truth, the method yields a mean kappa value of 88.59% and a mean total error of 0.50%. Experiments with real data also show satisfactory results under visual inspection. Performance tests on a workstation show that the method can process up to 1 million points per second. The original implementation was ported into a low-cost development board to demonstrate its feasibility to run in embedded systems, where throughput was improved by using programmable logic hardware acceleration. Analysis shows that real-time filtering is possible in a high-end board prototype, as it can process the amount of points per second that current lightweight scanners acquire with low-energy consumptionThis work was supported by the Ministry of Education, Culture, and Sport, Government of Spain (Grant Number TIN2016-76373-P), the Consellería de Cultura, Educación e Ordenación Universitaria (accreditation 2016–2019, ED431G/08, and ED431C 2018/2019), and the European Union (European Regional Development Fund—ERDF)S

A Developer-Friendly “Open Lidar Visualizer and Analyser” for Point Clouds With 3D Stereoscopic View

Light detection and ranging is being a hot topic in the remote sensing field, and the development of robust point cloud processing methods is essential for the adoption of this technology. In order to understand, evaluate, and show these methods, it is a key to visualize their outputs. Several visualization tools exist, although it is usually difficult to find the suited one for a specific application. On the one hand, proprietary (closed source) projects are not flexible enough because they cannot be modified to adapt them to particular applications. On the other hand, current open source projects lack an effortless way to create custom visualizations. For these reasons, we present Olivia, a developer-friendly open source visualization tool for point clouds. Olivia provides the backbone for any type of point cloud visualization, and it can be easily extended and tailored to meet the requirements of a specific application. It supports stereoscopic 3-D view, aiding both the evaluation and presentation of processing methods. In this paper, several cases of study are presented to demonstrate the usefulness of Olivia along with its computational performance.S

QTL detection for Aeromonas salmonicida resistance related traits in turbot (Scophthalmus maximus)

<p>Abstract</p> <p>Background</p> <p>Interactions between fish and pathogens, that may be harmless under natural conditions, often result in serious diseases in aquaculture systems. This is especially important due to the fact that the strains used in aquaculture are derived from wild strains that may not have had enough time to adapt to new disease pressures. The turbot is one of the most promising European aquaculture species. Furunculosis, caused by the bacterium <it>Aeromonas salmonicida</it>, produces important losses to turbot industry. An appealing solution is to achieve more robust broodstock, which can prevent or diminish the devastating effects of epizooties. Genomics strategies have been developed in turbot to look for candidate genes for resistance to furunculosis and a genetic map with appropriate density to screen for genomic associations has been also constructed. In the present study, a genome scan for QTL affecting resistance and survival to <it>A. salmonicida </it>in four turbot families was carried out. The objectives were to identify consistent QTL using different statistical approaches (linear regression and maximum likelihood) and to locate the tightest associated markers for their application in genetic breeding strategies.</p> <p>Results</p> <p>Significant QTL for resistance were identified by the linear regression method in three linkage groups (LGs 4, 6 and 9) and for survival in two LGs (6 and 9). The maximum likelihood methodology identified QTL in three LGs (5, 6 and 9) for both traits. Significant association between disease traits and genotypes was detected for several markers, some of them explaining up to 17% of the phenotypic variance. We also identified candidate genes located in the detected QTL using data from previously mapped markers.</p> <p>Conclusions</p> <p>Several regions controlling resistance to <it>A. salmonicida </it>in turbot have been detected. The observed concordance between different statistical methods at particular linkage groups gives consistency to our results. The detected associated markers could be useful for genetic breeding strategies. A finer mapping will be necessary at the detected QTL intervals to narrow associations and around the closely associated markers to look for candidate genes through comparative genomics or positional cloning strategies. The identification of associated variants at specific genes will be essential, together with the QTL associations detected in this study, for future marker assisted selection programs.</p