219 research outputs found
On the Hybrid Extension of CTL and CTL+
The paper studies the expressivity, relative succinctness and complexity of
satisfiability for hybrid extensions of the branching-time logics CTL and CTL+
by variables. Previous complexity results show that only fragments with one
variable do have elementary complexity. It is shown that H1CTL+ and H1CTL, the
hybrid extensions with one variable of CTL+ and CTL, respectively, are
expressively equivalent but H1CTL+ is exponentially more succinct than H1CTL.
On the other hand, HCTL+, the hybrid extension of CTL with arbitrarily many
variables does not capture CTL*, as it even cannot express the simple CTL*
property EGFp. The satisfiability problem for H1CTL+ is complete for triply
exponential time, this remains true for quite weak fragments and quite strong
extensions of the logic
On the Right Path: A Modal Logic for Supervised Learning
Formal learning theory formalizes the process of inferring a general result
from examples, as in the case of inferring grammars from sentences when
learning a language. Although empirical evidence suggests that children can
learn a language without responding to the correction of linguistic mistakes,
the importance of Teacher in many other paradigms is significant. Instead of
focusing only on learner(s), this work develops a general framework---the
supervised learning game (SLG)---to investigate the interaction between Teacher
and Learner. In particular, our proposal highlights several interesting
features of the agents: on the one hand,Learner may make mistakes in the
learning process, and she may also ignore the potential relation between
different hypotheses; on the other hand, Teacher is able to correct Learner's
mistakes, eliminate potential mistakes and point out the facts ignored by
Learner. To reason about strategies in this game, we develop a modal logic of
supervised learning (SLL). Broadly, this work takes a small step towards
studying the interaction between graph games, logics and formal learning
theory.Comment: The paper was accepted by LORI 2019. But due to the page-limit
constraints, that Proceedings version does not include any proofs. In this
version, we show the proofs for the result
Reactive models for biological regulatory networks
A reactive model, as studied by D. Gabbay and his collaborators,
can be regarded as a graph whose set of edges may be altered
whenever one of them is crossed. In this paper we show how reactive
models can describe biological regulatory networks and compare them
to Boolean networks and piecewise-linear models, which are some of the
most common kinds of models used nowadays. In particular, we show
that, with respect to the identification of steady states, reactive Boolean
networks lie between piecewise linear models and the usual, plain Boolean
networks. We also show this ability is preserved by a suitable notion of
bisimulation, and, therefore, by network minimisation.ERDF - The European Regional Development Fund through the Operational Programme for Competitiveness and Internationalisation - COMPETE 2020 Programme and by National Funds through the Portuguese funding agency, FCT - Fundação para a Ciência e a Tecnologia, within project POCI-01-0145-FEDER-030947. and project with reference UID/MAT/04106/2019 at CIDMA. D. Figueiredo also acknowledges the support given by FCT via the PhD scholarship PD/BD/114186/201
Effects of sleep on the academic performance of children with attention deficit and hyperactivity disorder
Attention deficit and hyperactivity disorder (ADHD) is commonly associated with disordered or disturbed sleep and the association of sleep problems with ADHD is complex and multidirectional. The purpose of this study was to analyze the relationship between sleep and academic performance, comparing children with ADHD and a control group without ADHD. Academic performance in Spanish, mathematics, and a foreign language (English) was evaluated. Different presentations of ADHD were considered as well as the potential difference between weekday and weekend sleep habits. The sample consisted of 75 children aged 6–12 in primary education. Accelerometry was used to study sleep, and school grades were used to gather information about academic performance. The results showed that ADHD influenced the amount of sleep during weekends, the time getting up at the weekends, weekday sleep efficiency, as well as academic performance. Given the effects that were seen in the variables linked to the weekend, it is necessary to consider a longitudinal design with which to determine if there is a cause and effect relationship
A note on reactive transitions and Reo connectors
The structure of a reactive transition system can to be modi
ed on the
y by e.g. removing, reversing or adding new transitions. The
topic has been studied by D. Gabbay and his collaborators in di erent
contexts. In this paper we take their work a step further, introducing a
suitable notion of bisimulation and obtaining a Hennessy-Milner theorem
with respect to a hybrid logic in which transition properties can be
expressed. Our motivation is to provide a characterisation of equivalence
for such systems in order to exploit their possible roles in the formal
description of software connectors in Reo, either from a behavioural (semantic)
or spatial (syntactic) point of view.“SmartEGOV/NORTE-01-0145-FEDER-000037”, supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (EFDR). Additional support was provided by the European Regional Development Fund through the Operational Programme for Competitiveness and Internationalisation - COMPETE 2020 and by National Funds through the Portuguese funding agency, FCT - Fundação para a Ciência e a Tecnologia within project UID/MAT/04106/2013 at CIDMA. The first author is also supported by an Individual Doctoral Grant (reference number PD/BD/114186/2016
Hybridisation at work
This paper presents the encoding of the hybridisation method into the HETS platform.FC
The Origin of Amerindians and the Peopling of the Americas According to HLA Genes: Admixture with Asian and Pacific People
The classical three-waves theory of American peopling through Beringia was based on a mixed anthropological and linguistic methodology. The use of mtDNA, Y chromosome and other DNA markers offers different results according to the different markers and methodologies chosen by different authors. At present, the peopling of Americas remains uncertain, regarding: time of population, number of peopling waves and place of peopling entrance among other related issues. In the present review, we have gathered most available HLA data already obtained about First Native American populations, which raise some doubts about the classical three waves of American peopling hypothesis. In summary, our conclusions are: 1) North West Canadian Athabaskans have had gene flow with: a) close neighboring populations, b) Amerindians, c) Pacific Islanders including East Australians and d) Siberians; 2) Beringia was probably not the only entrance of people to America: Pacific Ocean boat trips may have contributed to the HLA genetic American profile (or the opposite could also be true); 3) Amerindians entrance to America may have been different to that of Athabaskans and Eskimos and Amerindians may have been in their lands long before Athabaskans and Eskimos because they present and altogether different set of HLA-DRB1 allele frequencies; 4) Amerindians show very few “particular alleles”, almost all are shared with other Amerindians, Athabaskans and Pacific Islanders, including East Australians and Siberians; 5) Our results do not support the three waves model of American peopling, but another model where the people entrance is not only Beringia, but also Pacific Coast. Reverse migration (America to Asia) is not discarded and different movements of people in either direction in different times are supported by the Athabaskan population admixture with Asian-Pacific population and with Amerindians, 6) HLA variability is more common than allele veriability in Amerindians. Finally, it is shown that gene genealogy analises should be completed with allele frequency analyses in population relatednes and migrations studies
Completeness in hybrid type theory
We show that basic hybridization (adding nominals and @ operators) makes it possible to give straightforward Henkin-style completeness proofs even when the modal logic being hybridized is higher-order. The key ideas are to add nominals as expressions of type t, and to extend to arbitrary types the way we interpret @i in propositional and first-order hybrid logic. This means: interpret @iαa, where αa is an expression of any type a, as an expression of type a that rigidly returns the value that αa receives at the i-world. The axiomatization and completeness proofs are generalizations of those found in propositional and first-order hybrid logic, and (as is usual in hybrid logic) we automatically obtain a wide range of completeness results for stronger logics and languages. Our approach is deliberately low-tech. We don’t, for example, make use of Montague’s intensional type s, or Fitting-style intensional models; we build, as simply as we can, hybrid logic over Henkin’s logic.submittedVersionFil: Areces, Carlos Eduardo. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina.Fil: Blackburn, Patrick. University of Roskilde. Centre for Culture and Identity. Department of Philosophy and Science Studies; Dinamarca.Fil: Huertas, Antonia. Universitat Oberta de Catalunya; España.Fil: Manzano, María. Universidad de Salamanca; España.Ciencias de la Computació
Global environmental changes: setting priorities for Latin American coastal habitats.
The definitive version is available at www.blackwell-synergy.comThe Intergovernmental Panel for Climate Change (IPCC) reports that Global Environmental Changes (GEC) are occurring quicker than at any other time over the last 25 million years and impacting upon marine environments (Bellard et al., 2012). There is overwhelming evidence showing that GEC are affecting both the quality and quantity of the goods and services provided by a wide range of marine ecosystems. In order to discuss regional preparedness for global environmental changes, a workshop was held in Ilhabela, Brazil (22- 26 April 2012) entitled "Evaluating the Sensitivity of Central and South American Benthic Communities to Global Environmental Changes" that drew together scientists from ten Latin American and three European countries. © 2013 Blackwell Publishing Ltd
A hilbert-style axiomatisation for equational hybrid logic
This paper introduces an axiomatisation for equational hybrid logic based on previous axiomatizations and natural deduction systems for propositional and first-order hybrid logic. Its soundness and completeness is discussed. This work is part of a broader research project on the development a general proof calculus for hybrid logics
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