Loop pipelining with resource and timing constraints

Developing efficient programs for many of the current parallel computers is not easy due to the architectural complexity of those machines. The wide variety of machine organizations often makes it more difficult to port an existing program than to reprogram it completely. Therefore, powerful translators are necessary to generate effective code and free the programmer from concerns about the specific characteristics of the target machine. This work focuses on techniques to be used by an important class of translators, whose objective is to transform sequential programs into equivalent more parallel programs. The transformations are performed at instruction level in order to exploit low level parallelism and increase memory locality.Most of the current applications are programmed in languages which do not allow us to express parallelism between high-level sentences (as Pascal, C or Fortran). Furthermore, a lot of applications written ten or more years ago are still used today, and it is not feasible to rewrite such applications for many reasons (not only technical reasons, but also economic ones). Translators enable programmers to write the application in a familiar sequential programming language, without concerning their selves with the architecture of the target machine. Current compilers for parallel architectures not only translate a program written on a high-level language to the appropriate machine language, but also perform some transformations in the final code in order to execute the program in a more parallel way. The transformations improve the performance in the execution of the program by making use of the knowledge that the compiler has about the machine architecture. The semantics of the program remain intact after any transformation.Experiments show that limiting parallelization to basic blocks not included in loops limits maximum speedup. This is because loops often comprise a large portion of the parallelism available to be exploited in a program. For this reason, a lot of effort has been devoted in the recent years to parallelize loop execution. Several parallel computer architectures and compilation techniques have been proposed to exploit such a parallelism at different granularities. Multiprocessors exploit coarse grained parallelism by distributing entire loop iterations to different processors. Systems oriented to the high-level synthesis (HLS) of VLSI circuits, superscalar processors and very long instruction word (VLIW) processors exploit fine-grained parallelism at instruction level. This work addresses fine-grained parallelization of loops addressed to the HLS of VLSI circuits. Two algorithms are proposed for resource constraints and for timing constraints. An algorithm to reduce the number of registers required to execute a loop in a given architecture is also proposed.Postprint (published version

The EDINSOST project: improving sustainability education in spanish higher education

The EDINSOST R+D+i “Society Challenges” Project, funded by the Spanish Ministry of Economy and Competitiveness and the Spanish Ministry of Science, Innovation and Universities under the research challenge in the field of social change and innovation, aims to contribute to the improvement of social challenges across the (1) Spanish Strategy for Science, Technology and Innovation, (2) the State Plan of Scientific and Technical Research and Innovation, and (3) the European 2020 Strategy. The research is both highly multidisciplinary and contextualized and is applied in Ten Spanish Universities working together in the “Curriculum sustainability" group of the CRUE Sectorial Commission of Sustainability. The goal of this group is to create synergies and action frameworks agreed at a national level. This is an area of research action whose lack of common criteria for integrating sustainability competencies, learning processes and assessment hinders their achievement. To meet this challenge, frameworks and processes have been designed to facilitate the integration of sustainability into the university curriculum holistically through mapping and validation of pedagogical practices and the diagnosis of the state of Spanish universities, for which building materials for teaching and learning sustainability competencies have been developed. The project objectives and results are focused on: 1) Defining the map of sustainability competencies of the university degrees involved in the project, and establishing the framework to facilitate their integration in a holistic manner; 2) validating teaching strategies for the acquisition of sustainability competencies from a constructivist and community-oriented pedagogical approach; 3) diagnosing the state of faculty sustainability training needs and developing and pilot training proposals; and 4) diagnosing the state of learning of sustainability competencies in university students as well as preparing and piloting training proposals. The research methodology has an interpretive focus and uses quantitative and qualitative techniques to cover a population with three impact levels. Firstly, Bachelor and Master Degrees that integrate the three pillars of sustainability (environmental, social and economic). Secondly, and taking into account their long-term multiplier effect, special emphasis is made on five Bachelor and Master degrees in Education, since these graduates are the future teachers of the next generation of citizens. Finally, seven technological Bachelor Degrees are studied for their great impact on societal challenges.Peer ReviewedPostprint (published version

A mathematical formulation of the loop pipelining problem

This paper presents a mathematical model for the loop pipelining problem that considers several parameters for optimization and supports any combination of resource and timing constraints. The unrolling degree of the loop is one of the variables explored by the model. By using Farey’s series, an optimal exploration of the unrolling degree is performed and optimal solutions not considered by other methods are obtained. Finding an optimal schedule that minimizes resource and register requirements is solved by using an Integer linear programming (ILP) model. A novel paradigm called branch and prune is proposed to eficiently converge towards the optimal schedule and prune the search tree for integer solutions, thus drastically reducing the running time. This is the first formulation that combines the unrolling degree of the loop with timing and resource constraints in a mathematical model that guarantees optimal solutions.Peer ReviewedPostprint (author's final draft

La revolució del DNA

Avenços en genètica forens

Analysis of sustainability presence in Spanish higher education

Purpose: This paper analyzes the presence of sustainability in sixteen Spanish Higher Education curricula in the fields of Education and Engineering. Design/Methodology/Approach: The methodology employs two instruments: the Sustainability Map and the Sustainability Presence Map. These instruments enable the following: to analyze the number of subjects that develop sustainability and the sustainability presence level in each curriculum; to identify at what domain levels of the learning taxonomy sustainability is most developed; and to analyze whether a correlation exists between the sustainability presence and the number of subjects that develop sustainability in each curriculum. Findings: A wide variety of subjects develop sustainability in a given degree, depending on the university. The presence of sustainability is more homogeneous in education degrees than in engineering degrees. Education degrees have a greater presence of sustainability in the lower domain levels of the taxonomy, while in engineering degrees the lower levels of the taxonomy have a lower presence of sustainability than the higher levels. Finally, a correlation appears to exist between the number of subjects that develop sustainability in the curriculum and the sustainability presence. However, engineering degrees seem to need fewer subjects than education degrees to achieve the same degree of sustainability presence. Originality/Value: This paper proposes a methodology to measure sustainability presence that can be applicable to the curricula of a Higher Education degree if the corresponding Sustainability Map is available. To our knowledge, this is the largest study yet conducted to analyze the presence of sustainability in different Higher Education curricula.Peer ReviewedPostprint (author's final draft

Sistema VOTESCRIPT: una propuesta innovadora desarrollada para resolver los problemas clásicos de votación electrónica

En este artículo se presenta la descripción global de un sistema de voto telemático basado en criptografía avanzada y en el empleo de tarjetas inteligentes (proyecto VOTESCRIPT), destacando las aportaciones de este nuevo sistema sobre propuestas anteriores. Para enmarcar el trabajo desarrollado se presenta una panorámica general de la votación electrónica y se señalan los condicionantes que estas experiencias comportan. Asimismo, se resumen otras versiones particulares de VOTESCRIPT (proyecto VERA) y se comentan las características de una prueba experimental llevada a cabo para evaluar la viabilidad de la propuesta