976 research outputs found
Explicit linear kernels via dynamic programming
Several algorithmic meta-theorems on kernelization have appeared in the last
years, starting with the result of Bodlaender et al. [FOCS 2009] on graphs of
bounded genus, then generalized by Fomin et al. [SODA 2010] to graphs excluding
a fixed minor, and by Kim et al. [ICALP 2013] to graphs excluding a fixed
topological minor. Typically, these results guarantee the existence of linear
or polynomial kernels on sparse graph classes for problems satisfying some
generic conditions but, mainly due to their generality, it is not clear how to
derive from them constructive kernels with explicit constants. In this paper we
make a step toward a fully constructive meta-kernelization theory on sparse
graphs. Our approach is based on a more explicit protrusion replacement
machinery that, instead of expressibility in CMSO logic, uses dynamic
programming, which allows us to find an explicit upper bound on the size of the
derived kernels. We demonstrate the usefulness of our techniques by providing
the first explicit linear kernels for -Dominating Set and -Scattered Set
on apex-minor-free graphs, and for Planar-\mathcal{F}-Deletion on graphs
excluding a fixed (topological) minor in the case where all the graphs in
\mathcal{F} are connected.Comment: 32 page
The New Version of the Model MZE, Macroeconometric Model for the Eurozone
This paper presents the main improvements carried out to the macroeconometric model MZE since its creation in 2003. We have back-calculated the series over the period 1980-1995, in order to make the model more stable. To our knowledge, this paper is the first application of Kllians (1998) method to estimate coefficients and centered confidence intervals for an operational macroeconometric model. The new coefficients enable to get less inflationary responses to macroeconomic shocks than the previous version of MZE. The study is more nuanced and rigorous thanks to the confidence intervals around the main scenarios. It is thus possible to check the significance of the results at any horizon. At last, the new version of MZE enables to find conventional responses to international shocks, like the inflationary effect of a rise in oil prices or the delayed impact of a depreciation of the euro on the improvement of the trade balance.Macroeconometric modelling, Forecasting, Confidence interval, Bootstrap
P106 BIOMARKERS DEMONSTRATE DEGRADATION AND INFLAMMATION AS CHARACTERISTICS OF IDIOPATHIC OSTEOARTHRITIS (OA)
Competitive segmentation of the hippocampus and the amygdala from MRI scans
The hippocampus and the amygdala are two brain structures which play a central role in several fundamental cognitive
processes. Their segmentation from Magnetic Resonance Imaging (MRI) scans is a unique way to measure their atrophy
in some neurological diseases, but it is made difficult by their complex geometry. Their simultaneous segmentation is
considered here through a competitive homotopic region growing method. It is driven by relational anatomical
knowledge, which enables to consider the segmentation of atrophic structures in a straightforward way. For both
structures, this fast algorithm gives results which are comparable to manual segmentation with a better reproducibility.
Its performances regarding segmentation quality, automation and computation time, are amongst the best published
data.L’hippocampe et l’amygdale sont deux structures cérébrales intervenant dans plusieurs fonctions cognitives
fondamentales. Leur segmentation, à partir de volumes d’imagerie par résonance magnétique (IRM), est un
outil essentiel pour mesurer leur atteinte dans certaines pathologies neurologiques, mais elle est rendue
difficile par leur géométrie complexe. Nous considérons leur segmentation simultanée par une méthode de
déformation homotopique compétitive de régions. Celle-ci est guidée par des connaissances anatomiques
relationnelles ; ceci permet de considérer directement des structures atrophiées. Rapide, l’algorithme donne,
pour les deux structures, des résultats comparables à la segmentation manuelle avec une meilleure
reproductibilité. Ses performances, concernant la qualité de la segmentation, le degré d’automatisation
et le temps de calcul, sont parmi les meilleures de la littérature
66 A NEW SERUM-BASED ASSAY FOR TYPE II COLLAGEN HELICAL PEPTIDE (SERUM HELIX-II) IS ASSOCIATED WITH LONG-TERM RADIOLOGICAL PROGRESSION IN KNEE OSTEOARTHRITIS
Estudo da curva de crescimento de bubalinos da raça Murrah criados no estado do Rio Grande do Sul.
Objetivou-se identificar um modelo, dentre oito citados na literatura, que melhor descreva a curva de crescimento de bubalinos da raça Murrah criados no estado de Rio Grande do Sul. Foram utilizadas informações de 42 machos e 48 fêmeas da raça Murrah, nascidos entre 2009 e 2011, totalizando 624 pares de registros peso-idade do nascimento até 750 dias de idades. Os parâmetros dos modelos foram estimados por meio de regressão não-linear pelo procedimento NLIN (SAS system), utilizando-se o método de Gauss Newton. Os critérios para a escolha do melhor ajuste foram: o quadrado médio dos resÃduos (QMR), o desvio médio absoluto (DMA), o Ãndice e a avaliação visual do gráfico dos valores observados e estimados. Com base no do QMR, DMA e o Ãndice, constatou-se que o modelo Richards (1959) apresentou melhor ajuste, seguido pelo modelo Von Bertalanffy (1957). Com isto, o modelo Richards (1959) dentre os testados foi capaz de descrever o crescimento de búfalos da raça Murrah criados no estado do Rio Grande do Sul
A linear kernel for planar red-blue dominating set
In the Red-Blue Dominating Set problem, we are given a bipartite graph G = (V B ∪ V R , E) and an integer k, and asked whether G has a subset D ⊆ V B of at most k 'blue' vertices such that each 'red' vertex from V R is adjacent to a vertex in D. We provide the first explicit linear kernel for this problem on planar graphs
Estimativa de parâmetros e associações genéticas entre perÃmetro escrotal na desmama e caracterÃsticas produtivas na fase pós-desmama de bubalinos da raça Murrah.
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