An Efficient generic algorithm for the generation of unlabelled cycles

In this report we combine two recent generation algorithms to obtain a new algorithm for the generation of unlabelled cycles. Sawada's algorithm lists all k-ary unlabelled cycles with fixed content, that is, the number of occurences of each symbol is fixed and given a priori. The other algorithm, by the authors, generates all multisets of objects with given total size n from any admissible unlabelled class A. By admissible we mean that the class can be specificied using atomic classes, disjoints unions, products, sequences, (multi)sets, etc. The resulting algorithm, which is the main contribution of this paper, generates all cycles of objects with given total size n from any admissible class A. Given the generic nature of the algorithm, it is suitable for inclusion in combinatorial libraries and for rapid prototyping. The new algorithm incurs constant amortized time per generated cycle, the constant only depending in the class A to which the objects in the cycle belong.Postprint (published version

Assessment of information-driven decision-making in the SME

The use of analytics in decision -making processes is a key element for organizations to be competitive. However, experience indicates that many organizations still have not managed to fully understand how to use properly the available data for diagnosing, improving a nd controlling processes or modelling, predicting and discovering business opportunities. This situation is even more exaggerated among small and medium enterprises (SMEs). An essential first step for SMEs to start using analytics is a correct assessment o f their decision -making processes and use of data. This will help them understanding their current situation, seeing the potential of adopting analytical practices and decide their approach to analytics. Therefore, the assessment we propose is managerial a nd strategic; thus, it is not aimed at detecting problems such as: errors in the data to make an invoice, not having the correct version of a drawing in the shop or a wrong date in a project plan... Undoubtedly, t hese issues are very important but they are not the objective. The results from applying the proposed assessment tool in several pilot SMEs are expected to serve as the basis for improving the tool and developing a maturity model and a roadmap for improving their proficiency in information -driven d ecision -makingPostprint (published version

Neural network modelling of Abbott-Firestone roughness parameters in honing processes

In present study, three roughness parameters defined in the Abbott-Firestone or bearing area curve, Rk, Rpk and Rvk, were modelled for rough honing processes by means of artificial neural networks (ANN). Input variables were grain size and density of abrasive, pressure of abrasive stones on the workpiece's surface, tangential or rotation speed of the workpiece and linear speed of the honing head. Two strategies were considered, either use of one network for modelling the three parameters at the same time or use of three networks, one for each parameter. Overall best neural network consists of three networks, one for each roughness parameter, with one hidden layer having 25, nine and five neurons for Rk, Rpk and Rvk respectively. However, use of one network for the three roughness parameters would allow addressing an indirect model. In this case, best solution corresponds to two hidden layers having 26 and 11 neurons.Peer ReviewedPostprint (author's final draft

Extending OmpSs for OpenCL kernel co-execution in heterogeneous systems

© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Heterogeneous systems have a very high potential performance but present difficulties in their programming. OmpSs is a well known framework for task based parallel applications, which is an interesting tool to simplify the programming of these systems. However, it does not support the co-execution of a single OpenCL kernel instance on several compute devices. To overcome this limitation, this paper presents an extension of the OmpSs framework that solves two main objectives: the automatic division of datasets among several devices and the management of their memory address spaces. To adapt to different kinds of applications, the data division can be performed by the novel HGuided load balancing algorithm or by the well known Static and Dynamic. All this is accomplished with negligible impact on the programming. Experimental results reveal that there is always one load balancing algorithm that improves the performance and energy consumption of the system.This work has been supported by the University of Cantabria with grant CVE-2014-18166, the Generalitat de Catalunya under grant 2014-SGR-1051, the Spanish Ministry of Economy, Industry and Competitiveness under contracts TIN2016- 76635-C2-2-R (AEI/FEDER, UE) and TIN2015-65316-P. The Spanish Government through the Programa Severo Ochoa (SEV-2015-0493). The European Research Council under grant agreement No 321253 European Community’s Seventh Framework Programme [FP7/2007-2013] and Horizon 2020 under the Mont-Blanc Projects, grant agreement n 288777, 610402 and 671697 and the European HiPEAC Network.Peer ReviewedPostprint (published version

Human activity recognition on smartphones using a multiclass hardware-friendly support vector machine

Activity-Based Computing aims to capture the state of the user and its environment by exploiting heterogeneous sensors in order to provide adaptation to exogenous computing resources. When these sensors are attached to the subject’s body, they permit continuous monitoring of numerous physiological signals. This has appealing use in healthcare applications, e.g. the exploitation of Ambient Intelligence (AmI) in daily activity monitoring for elderly people. In this paper, we present a system for human physical Activity Recognition (AR) using smartphone inertial sensors. As these mobile phones are limited in terms of energy and computing power, we propose a novel hardware-friendly approach for multiclass classification. This method adapts the standard Support Vector Machine (SVM) and exploits fixed-point arithmetic for computational cost reduction. A comparison with the traditional SVM shows a significant improvement in terms of computational costs while maintaining similar accuracy, which can contribute to develop more sustainable systems for AmI.Peer ReviewedPostprint (author's final draft

Connectionist techniques to approach sustainability modelling

When defining a context of sustainability, capturing the complexity of data and extracting as much information as possible are fundamental challenges. Normally, quantitative and qualitative indicators are defined. While the definition and calculation of the former is direct, the latter are difficult to manage. This document provides tools based on connectionist techniques for managing complex information combining the use of imprecise and qualitative variables. The application of these tools to evaluate non-numerical sustainability indicators is presented. The results obtained in some first approaches are briefly presented to illustrate the connectionist paradigm

CellSim: a validated modular heterogeneous multiprocessor simulator

As the number of transistors on a chip continues increasing the power consumption has become the most important constraint in processors design. Therefore, to increase performance, computer architects have decided to use multiprocessors. Moreover, recent studies have shown that heterogeneous chip multiprocessors have greater potential than homogeneous ones. We have built a modular simulator for heterogeneous multiprocessors that can be configure to model IBM's Cell Processor. The simulator has been validated against the real machine to be used as a research tool.Peer ReviewedPostprint (published version

Barcelona OpenMP tasks suite: a set of benchmarks targeting the exploitation of task parallelism in OpenMP

Traditional parallel applications have exploited regular parallelism, based on parallel loops. Only a few applications exploit sections parallelism. With the release of the new OpenMP specification (3.0), this programming model supports tasking. Parallel tasks allow the exploitation of irregular parallelism, but there is a lack of benchmarks exploiting tasks in OpenMP. With the current (and projected) multicore architectures that offer many more alternatives to execute parallel applications than traditional SMP machines, this kind of parallelism is increasingly important. And so, the need to have some set of benchmarks to evaluate it. In this paper, we motivate the need of having such a benchmarks suite, for irregular and/or recursive task parallelism. We present our proposal, the Barcelona OpenMP Tasks Suite (BOTS), with a set of applications exploiting regular and irregular parallelism, based on tasks. We present an overall evaluation of the BOTS benchmarks in an Altix system and we discuss some of the different experiments that can be done with the different compilation and runtime alternatives of the benchmarks.Peer ReviewedPostprint (published version

Plan de negocios para una plataforma de entretenimiento pago musical en vivo

El plan de negocios propone el establecimiento de una plataforma de intermediación digital que permita a músicos profesionales e independientes realizar transmisiones en vivo a su público y obtener ingresos a partir de suscripciones, pago de entradas y propinas directamente al artista, teniendo como principales atractivos las herramientas innovadoras de interacción y opciones de rentabilización que irán en su mayoría al músico, así como información y distintos servicios adicionales que permitirán expandir las opciones de interacción y creación de contenido para expandir el alcance de la plataforma a partir de sus creadores. Las principales variables del contexto están relacionadas con el incremento en los modelos de plataformas digitales por suscripción y el crecimiento del mercado de entretenimiento digital, con un crecimiento sostenido en los últimos años y potenciado por el contexto de pandemis que afecta especialmente a los músicos por las restricciones a los conciertos. En suma, esta plataforma busca brindar una experiencia nueva y diferenciada, que permitaa los artistas rentabilizar su creación, y llegar a un público cada vez mayor, generando una comunidad alrededor de su contenido y la oportunidad de rentabilizarlo