Parallel Working-Set Search Structures

In this paper we present two versions of a parallel working-set map on p processors that supports searches, insertions and deletions. In both versions, the total work of all operations when the map has size at least p is bounded by the working-set bound, i.e., the cost of an item depends on how recently it was accessed (for some linearization): accessing an item in the map with recency r takes O(1+log r) work. In the simpler version each map operation has O((log p)^2+log n) span (where n is the maximum size of the map). In the pipelined version each map operation on an item with recency r has O((log p)^2+log r) span. (Operations in parallel may have overlapping span; span is additive only for operations in sequence.) Both data structures are designed to be used by a dynamic multithreading parallel program that at each step executes a unit-time instruction or makes a data structure call. To achieve the stated bounds, the pipelined data structure requires a weak-priority scheduler, which supports a limited form of 2-level prioritization. At the end we explain how the results translate to practical implementations using work-stealing schedulers. To the best of our knowledge, this is the first parallel implementation of a self-adjusting search structure where the cost of an operation adapts to the access sequence. A corollary of the working-set bound is that it achieves work static optimality: the total work is bounded by the access costs in an optimal static search tree.Comment: Authors' version of a paper accepted to SPAA 201

Towards Formal Interaction-Based Models of Grid Computing Infrastructures

Grid computing (GC) systems are large-scale virtual machines, built upon a massive pool of resources (processing time, storage, software) that often span multiple distributed domains. Concurrent users interact with the grid by adding new tasks; the grid is expected to assign resources to tasks in a fair, trustworthy way. These distinctive features of GC systems make their specification and verification a challenging issue. Although prior works have proposed formal approaches to the specification of GC systems, a precise account of the interaction model which underlies resource sharing has not been yet proposed. In this paper, we describe ongoing work aimed at filling in this gap. Our approach relies on (higher-order) process calculi: these core languages for concurrency offer a compositional framework in which GC systems can be precisely described and potentially reasoned about.Comment: In Proceedings DCM 2013, arXiv:1403.768

Improving photon-hadron discrimination based on cosmic ray surface detector data

The search for photons at EeV energies and beyond has considerable astrophysical interest and will remain one of the key challenges for ultra-high energy cosmic ray (UHECR) observatories in the near future. Several upper limits to the photon flux have been established since no photon has been unambiguously observed up to now. An improvement in the reconstruction efficiency of the photon showers and/or better discrimination tools are needed to improve these limits apart from an increase in statistics. Following this direction, we analyze in this work the ability of the surface parameter Sb, originally proposed for hadron discrimination, for photon search. Semi-analytical and numerical studies are performed in order to optimize Sb for the discrimination of photons from a proton background in the energy range from 10^18.5 to 10^19.6 eV. Although not shown explicitly, the same analysis has been performed for Fe nuclei and the corresponding results are discussed when appropriate. The effects of different array geometries and the underestimation of the muon component in the shower simulations are analyzed, as well as the Sb dependence on primary energy and zenith angle.Comment: 9 pages, 19 Figures. Accepted in Astroparticle Physics on May 31th, 201

Design of management accounting systems in public administration: A case study

Purpose: This work aims to design a management accounting system (MAC) framework for a public sector organization. Many public entities experience difficulties in designing and implementing MACs. Our proposal intends to be as a useful tool in the accomplishment of this task. Methodology: A comprehensive case study of the organizational structure and operational activity was performed, following an interventionist research with the aim of designing a cost accounting system for a public sector organization. Results: A framework for implementing a management accounting system in the public sector is proposed. Originality: The literature highlights the difficulty and failure in the implementation of management accounting systems in the public sector organizations. This research intends to contribute to this discussion, presenting a roadmap for the MAC’s implementation process, highlighting possible obstacles that may arise.info:eu-repo/semantics/publishedVersio

The Atmospheric Monitoring System of the JEM-EUSO Space Mission

An Atmospheric Monitoring System (AMS) is a mandatory and key device of a space-based mission which aims to detect Ultra-High Energy Cosmic Rays (UHECR) and Extremely-High Energy Cosmic Rays (EHECR) from Space. JEM-EUSO has a dedicated atmospheric monitoring system that plays a fundamental role in our understanding of the atmospheric conditions in the Field of View (FoV) of the telescope. Our AMS consists of a very challenging space infrared camera and a LIDAR device, that are being fully designed with space qualification to fulfil the scientific requirements of this space mission. The AMS will provide information of the cloud cover in the FoV of JEM-EUSO, as well as measurements of the cloud top altitudes with an accuracy of 500 m and the optical depth profile of the atmosphere transmittance in the direction of each air shower with an accuracy of 0.15 degree and a resolution of 500 m. This will ensure that the energy of the primary UHECR and the depth of maximum development of the EAS ( Extensive Air Shower) are measured with an accuracy better than 30\% primary energy and 120 $g/cm^2$ depth of maximum development for EAS occurring either in clear sky or with the EAS depth of maximum development above optically thick cloud layers. Moreover a very novel radiometric retrieval technique considering the LIDAR shots as calibration points, that seems to be the most promising retrieval algorithm is under development to infer the Cloud Top Height (CTH) of all kind of clouds, thick and thin clouds in the FoV of the JEM-EUSO space telescope

Sobre la poesía de Camilo Pessanha

Camilo Pessanha nació en 1867, en Coimbra (Portugal), y murió en Macao (1926). Licenciado en derecho (1891), fue profesor de filosofía del liceo de Macao, a donde llegó en 1894, y también registrador de propiedad y magistrado. Se interesó por la estética y la literatura oriental, y reunió una significativa colección de arte chino. Desde 1885 publicó en periódicos y revistas su poesía, que en parte sería recogida en el volumen Clepsydra (Lisboa, 1920)

Development of New-Concept Clean Technologies to Extract Metals from Primary and Secondary Sources

Development of new-concept hydrometallurical technologies promoted by Tecnicas Reunidas is providing efficient and clean means for metals extraction from diverse primary & secondary sources, such as conventional or low-grade concentrates and ores, lead-acid batteries, domestic batteries, effluents from electronic industry, etc. Rele-vant characteristics of the recently developed processes regarding extraction of zinc, lead, silver, nickel and copper metals are the following: environmentally friendly, value added products and by-products, flexibility to a great variety of feed materials, adapted to local market requirements, easy to be combined with existing plants available for small and large capacities and on-site installation close to the metal sources