Cambio y persistencia en el espacio geográfico: consideraciones para la reflexión medioambiental.

Tras analizar las relaciones entre espacio, naturaleza y sociedad, la atenojén se centra en los aspectos dinámicos del espacio, destacando las ideas de cambio e inercia territorial y subrayando el papel de las distintas escalas temporales y espaciales.Tras analizar las relaciones entre espacio, naturaleza y sociedad, la atenojén se centra en los aspectos dinámicos del espacio, destacando las ideas de cambio e inercia territorial y subrayando el papel de las distintas escalas temporales y espaciales

Abstract verification and debugging of constraint logic programs

The technique of Abstract Interpretation [13] has allowed the development of sophisticated program analyses which are provably correct and practical. The semantic approximations produced by such analyses have been traditionally applied to optimization during program compilation. However, recently, novel and promising applications of semantic approximations have been proposed in the more general context of program verification and debugging [3],[10],[7]

Exploiting Term Hiding to Reduce Run-time Checking Overhead

One of the most attractive features of untyped languages is the flexibility in term creation and manipulation. However, with such power comes the responsibility of ensuring the correctness of these operations. A solution is adding run-time checks to the program via assertions, but this can introduce overheads that are in many cases impractical. While static analysis can greatly reduce such overheads, the gains depend strongly on the quality of the information inferred. Reusable libraries, i.e., library modules that are pre-compiled independently of the client, pose special challenges in this context. We propose a technique which takes advantage of module systems which can hide a selected set of functor symbols to significantly enrich the shape information that can be inferred for reusable libraries, as well as an improved run-time checking approach that leverages the proposed mechanisms to achieve large reductions in overhead, closer to those of static languages, even in the reusable-library context. While the approach is general and system-independent, we present it for concreteness in the context of the Ciao assertion language and combined static/dynamic checking framework. Our method maintains the full expressiveness of the assertion language in this context. In contrast to other approaches it does not introduce the need to switch the language to a (static) type system, which is known to change the semantics in languages like Prolog. We also study the approach experimentally and evaluate the overhead reduction achieved in the run-time checks.Comment: 26 pages, 10 figures, 2 tables; an extension of the paper version accepted to PADL'18 (includes proofs, extra figures and examples omitted due to space reasons

Fast preparation of single hole spin in InAs/GaAs quantum dot in Voigt geometry magnetic field

The preparation of a coherent heavy-hole spin via ionization of a spin-polarized electron-hole pair in an InAs/GaAs quantum dot in a Voigt geometry magnetic field is investigated. For a dot with a 17 ueV bright-exciton fine-structure splitting, the fidelity of the spin preparation is limited to 0.75, with optimum preparation occurring when the effective fine-structure of the bright-exciton matches the in-plane hole Zeeman energy. In principle, higher fidelities can be achieved by minimizing the bright-exciton fine-structure splitting.Comment: 8 pages, 10 figs, published PRB 85 155310 (2012

Winter precipitation over the Iberian peninsula and its relationship to circulation indices

International audienceWinter precipitation variability over the Iberian peninsula was investigated by obtaining the spatial and temporal patterns. Empirical Orthogonal Functions were used to describe the variance distribution and to compress the precipitation data into a few modes. The corresponding spatial patterns divide the peninsula into climatic regions according to precipitation variations. The associated time series were related to large scale circulation indices and tropical sea surface temperature anomalies by using lag cross-correlation and cross-spectrum. The major findings are: the most influential indices for winter precipitation were the North Atlantic Oscillation and the East Atlantic/West Russian pattern; coherent oscillations were detected at about eight years between precipitation and the North Atlantic Oscillation and some dynamic consequences of the circulation on precipitation over the Iberian peninsula were examined during drought and wet spells. In the end statistical methods have been proposed to downscale seasonal precipitation prediction. Keywords: Winter precipitation, circulation indices, Iberian peninsula climate, climate variations, precipitation tren

A theory of relation learning and cross-domain generalization

People readily generalize knowledge to novel domains and stimuli. We present a theory, instantiated in a computational model, based on the idea that cross-domain generalization in humans is a case of analogical inference over structured (i.e., symbolic) relational representations. The model is an extension of the Learning and Inference with Schemas and Analogy (LISA; Hummel & Holyoak, 1997, 2003) and Discovery of Relations by Analogy (DORA; Doumas et al., 2008) models of relational inference and learning. The resulting model learns both the content and format (i.e., structure) of relational representations from nonrelational inputs without supervision, when augmented with the capacity for reinforcement learning it leverages these representations to learn about individual domains, and then generalizes to new domains on the first exposure (i.e., zero-shot learning) via analogical inference. We demonstrate the capacity of the model to learn structured relational representations from a variety of simple visual stimuli, and to perform cross-domain generalization between video games (Breakout and Pong) and between several psychological tasks. We demonstrate that the model’s trajectory closely mirrors the trajectory of children as they learn about relations, accounting for phenomena from the literature on the development of children’s reasoning and analogy making. The model’s ability to generalize between domains demonstrates the flexibility afforded by representing domains in terms of their underlying relational structure, rather than simply in terms of the statistical relations between their inputs and outputs

Acessibilidade e SIG no planeamento em saúde: uma abordagem baseada em modelos de alocação-localização

As políticas e as práticas de planeamento em saúde devera promover o acesso aos cuidados de saúde primarios, urna área na qual a distribuicao dos equipamentos e a acessibilidade da populacáo assumem particular relevancia. O sistema de saúde deve proporcionar níveis de acessibilidade adequados a cada grupo funcional, particularmente nos territorios dotados de urna populacáo mais envelhecida. O aumento do número de idosos torna mais premente o papel que as políticas públicas de saúde podem ter na reducáo das desigualdades em saúde. Neste artigo, pretende-se avahar o contributo dos modelos de localizacao para a identificacao da localizacao mais adequada das unidades de cuidados de saúde primarios e comparar como variam os níveis de acessibilidade entre as solucóes propostas pelos varios modelos. Da aplicacao conduzida retirou-se que estas solucóes permitem obter ganhos em termos de acessibilidade, melhorando a proximidade entre os equipamentos e os utentes. ----------ABSTRACT---------- The health system should be endowed with adequate accessibility levels to each functional population cohort it envisages to serve. In the case we are before higher levels of elder population, those health necessities increase. The location of health facilities should have in mind the demographic structure of each territory. Accordingly, the increase of elder people turns more needed public health policies addressed to mitigate social exclusion processes that can occur. Health public policies and planning practices should promote accessibility to primary health care facilities. In such a context, the location of those facilities and its accessibility have a particular importance. In this article, we envisage to evaluate the contribution of the location models to identify the more adequate locations of the health facilities and to check how the accessibility levels vary according to the results obtained from those models

Context-sensitive multivariant assertion checking in modular programs

We propose a modular, assertion-based system for verification and debugging of large logic programs, together with several interesting models for checking assertions statically in modular programs, each with different characteristics and representing different trade-offs. Our proposal is a modular and multivariant extensión of our previously proposed abstract assertion checking model and we also report on its implementation in the CiaoPP system. In our approach, the specification of the program, given by a set of assertions, may be partial, instead of the complete specification required by raditional verification systems. Also, the system can deal with properties which cannot always be determined at compile-time. As a result, the proposed system needs to work with safe approximations: all assertions proved correct are guaranteed to be valid and all errors actual errors. The use of modular, context-sensitive static analyzers also allows us to introduce a new distinction between assertions checked in a particular context or checked in general