A generic framework to integrate data caches in the WCET analysis of real-time systems

Worst-case execution time (WCET) analysis of systems with data caches is one of the key challenges in real-time systems. Caches exploit the inherent reuse properties of programs by temporarily storing certain memory contents near the processor, in order that further accesses to such contents do not require costly memory transfers. Current worst-case data cache analysis methods focus on specific cache organizations (set-associative LRU, locked, ACDC, etc.), most of the times adapting techniques designed to analyze instruction caches. On the other hand, there are methodologies to analyze the data reuse of a program, independently of the data cache. In this paper we propose a generic WCET analysis framework to analyze data caches taking profit of such reuse information. It includes the categorization of data references and their integration in an IPET model. We apply it to a conventional LRU cache, an ACDC, and other baseline systems, and compare them using the TACLeBench benchmark suite. Our results show that persistence-based LRU analyses dismiss essential information on data, and a reuse-based analysis improves the WCET bound around 17% in average. In general, the best WCET estimations are obtained with optimization level 2, where the ACDC cache performs 39% better than a set-associative LRU

Aurora Leal. Pensar el Pensamiento. Un Estudio sobre el Respeto, el Reconocimiento y la Escucha Mediante Dibujo y Expresión Corporal.

Reseña crítica del libro AURORA LEAL. Pensar el Pensamiento. Un Estudio sobre el Respeto, el Reconocimiento y la Escucha Mediante Dibujo y Expresión Corporal. Ed. Octaedro, 2020. Barcelona

Conceptualización, diseño y desarrollo gráfico de la Sociedad Valenciana del Dolor, VALDOLOR

[ES] El presente trabajo de fin de grado pretende llevar a cabo la conceptualización, diseño y planificación gráfica de la imagen gráfica para la Sociedad Valenciana del Dolor, VALDOLOR.[EN] Conceptualization, design and graphic development of the Valencian Pain Society, VALDOLOR.Silva Segarra, V. (2018). Conceptualización, diseño y desarrollo gráfico de la Sociedad Valenciana del Dolor, VALDOLOR. Universitat Politècnica de València. http://hdl.handle.net/10251/100280TFG

UDWDM-PON using low-cost coherent transceivers with limited tunability and heuristic DWA

A new Passive Optical Network (PON) for access, making use of Ultra Dense Wavelength Division Multiplexing (UDWDM) by densely spacing channels at few GHz, and introducing the “wavelength-to-the-user” concept, is proposed. The key challenge will be developing low-cost coherent transceivers, providing an excellent selectivity while avoiding filters, and furnishing high sensitivity, which will allow high splitting ratios, large number of users and long distance reach. The Optical Distribution Network (ODN) at the outside plant is based on splitters and kept compatible with legacy systems. Optical Network Unit (ONU) designs realized with coherent transceivers using one or two lasers are presented and the corresponding Optical Line Terminal (OLT) architectures are introduced. The ONUs at customer premises own lasers with limited thermal tunability and their wavelengths are randomly distributed in a band. By using heuristic Dynamic Wavelength Assignment (DWA) schemes and extending the original working band, the required optical band is obtained and optimized. In activation processes, ONU acceptances up to 99.9% are achieved. Furthermore, in operation scenario under indoors and also under outdoors environmental conditions, ONU blocking probabilities below 0.1% and ONU availability ratios (OARs) up to 99.9% are demonstrated. The PON is dimensioned according to the number of deployed users and system reach; moreover, power safety and also fiber nonlinearities constraints are evaluated, illustrating the characteristics of the projected network. Finally, the coexistence with legacy networks is discussed.Peer ReviewedPostprint (author's final draft

Reducing the WCET and analysis time of systems with simple lockable instruction caches

One of the key challenges in real-time systems is the analysis of the memory hierarchy. Many Worst-Case Execution Time (WCET) analysis methods supporting an instruction cache are based on iterative or convergence algorithms, which are rather slow. Our goal in this paper is to reduce the WCET analysis time on systems with a simple lockable instruction cache, focusing on the Lock-MS method. First, we propose an algorithm to obtain a structure-based representation of the Control Flow Graph (CFG). It organizes the whole WCET problem as nested subproblems, which takes advantage of common branch-and-bound algorithms of Integer Linear Programming (ILP) solvers. Second, we add support for multiple locking points per task, each one with specific cache contents, instead of a given locked content for the whole task execution. Locking points are set heuristically before outer loops. Such simple heuristics adds no complexity, and reduces the WCET by taking profit of the temporal reuse found in loops. Since loops can be processed as isolated regions, the optimal contents to lock into cache for each region can be obtained, and the WCET analysis time is further reduced. With these two improvements, our WCET analysis is around 10 times faster than other approaches. Also, our results show that the WCET is reduced, and the hit ratio achieved for the lockable instruction cache is similar to that of a real execution with an LRU instruction cache. Finally, we analyze the WCET sensitivity to compiler optimization, showing for each benchmark the right choices and pointing out that O0 is always the worst option

Estudio y análisis de materiales granulares de la cantera Tigre para el diseño de bases y subbases estructurales de carreteras.

El trabajo de investigación que presentamos a continuación estudia y analiza las propiedades físico-mecánicas del material granular que se produce en la cantera Tigre ubicada en la parroquia Ancón, provincia de Santa Elena; con el fin de comparar los resultados obtenidos mediante ensayos de laboratorio versus el criterio de aceptación que prevén la utilización de materiales granulares para base y subbase en una estructura de pavimento en carreteras cumpliendo con las normas técnicas ecuatorianas del Ministerio de Transporte y Obras Públicas MTOP, con el fin de darle un uso correcto a estos materiales y que esta información sea aprovechada para la construcción de vías de desarrollo dentro de la provincia de Santa Elena con este recurso natural. El alcance de esta investigación relata estudios de reflexión sísmica, para conocer el volumen estimado de la cantera Tigre, ensayos de difracción de rayos x con el cual se obtuvo la mineralogía que compone este material y múltiples ensayos de laboratorio para el análisis geotécnico de las muestras tomadas en sitio. Una vez obtenido todos los resultados se muestran las conclusiones que nos permiten conocer su utilidad en una obra civil referente al tema vial en mención

Mechanical properties of highly textured porous Ni-YSZ and Co-YSZ cermets produced from directionally solidified eutectics

It is well known that several ceramic materials develop an usual; and sometimes unique; combination of properties as a result of mixing different phases with similar expansion coefficients. Sometimes they are elastically stiff, have low thermal expansion coefficients, and are resistant to chemical attack. As this paper will show, their mechanical properties are also enhanced. Nanoindentation is used to measure the mechanical properties for each phase of NiO-YSZ and CoO-YSZ eutectics produced by the laser floating zone technique, and also the analogues Ni-YSZ and Co-YSZ cermets produced by reduction from the eutectic precursors. The different tests have been performed at 100 nm, in order to obtain an imprint lower than the size of the secondary phase and extract the hardness and Young's modulus. Moreover, several tests have been performed at 2000 nm of indentation range to obtain the response of each material. The different imprints have been visualized by Atomic Force Microscopy

The effects of the Nordic hamstring exercise on sprint performance and eccentric knee flexor strength: A systematic review and meta-analysis of intervention studies among team sport players

The primary aim of this study was to investigate the effects of the Nordic hamstring exercise (NH E ) on sprint performance (i.e., 5, 10 and 20 m) and explore associations between study characteristics and sprint outcomes in team sport players. Secondary aims were to (1) investigate the effects of the NH E on eccentric strength of the knee flexors (ES KF ) with categorical subgroup analysis to determine differences between recreationally, well-trained individuals and young athletes, (2) determine the relation between ES KF and sprint performance in team sport players, and (3) explore the effect of study characteristics (i.e., weekly volume, time duration and body mass) on ES KF .Medicin