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1.
Resource-Bounded Paraconsistent Inference 总被引:1,自引:0,他引:1
In this paper, a new framework for reasoning from inconsistent propositional belief bases is presented. A family of resource-bounded paraconsistent inference relations is introduced. Such inference relations are based on S-3 entailment, an inference relation logically weaker than the classical one and parametrized by a set S of propositional variables. The computational complexity of our relations is identified, and their logical properties are analyzed. Among the strong features of our framework is the fact that tractability is ensured each time |S| is bounded and a limited amount of knowledge is taken into account within the belief base. Furthermore, binary connectives , behave in a classical manner. Finally, our framework is general enough to encompass several paraconsistent multi-valued logics (including S-3, J
3 and its restrictions), the standard coherence-based approach to inconsistency handling (based on the selection of consistent subbases) and some signed systems for paraconsistent reasoning as specific cases. 相似文献
2.
Yves Richard Nadège Martiny Mathieu Rouault Nathalie Philippon Yann Tracol Thierry Castel 《International journal of remote sensing》2013,34(21):6763-6782
In semi-arid African regions (annual rainfall between 200 and 600 mm), variability of vegetative activity is mainly due to the rainfall of the current rainy season. In most of South Africa, the rainy season occurs from October to March. On average, vegetative activity lags rainfall by 1 to 2 months. The interannual variability in early summer (December to September) normalized difference vegetation index (NDVI) depends primarily on precipitation at the beginning (October to November) of the rainy season. However, once this primary control is removed, the residual interannual variability in NDVI highlights a double memory effect: a 1-year effect, referred to as Mem1, and a 7- to 10-month effect, referred to as Mem2. This article aims at better describing the influence of soil and vegetation characteristics on these two memory effects. The data sets used in this study are as follows: (1) a 19-year NDVI time series from National Oceanic and Atmospheric Administration (NOAA) satellites, (2) rainfall records from a network of 1160 rain-gauge stations compiled by the Water Research Commission (WRC), (3) vegetation types from Global Land Cover (GLC) 2000 and (4) soil characteristics from the soil and terrain database for Southern Africa (SOTERSAF). Results indicate that among 20–30% of NDVI variance that is not explained by the concurrent rainfall, one-third is explained by the two memory effects. Mem1 is found to have maximum effect in the northwest of our study domain, near the Botswana boundary, in the South Kalahari. Associated conditions are open grasslands growing on Arenosols. Mem1 is less important in the southeast, particularly in open grassland with shrubs growing on Cambisols. Thus, Mem1 mainly depends on soil texture. Mem2 is more widespread and its influence is the greatest in the centre, the south and the east of our domain. It is related to rainfall from January to April, which controls, beyond the intervening dry season, the interannual variations of NDVI (December to September) at the beginning of the next rainy season. Through these new findings, this article emphasizes again the high potential of remote-sensing techniques to monitor and understand the dynamics of semi-arid environments. 相似文献
3.
Sulaiman Al-Khattaf Syed A. Ali Abdullah M. Aitani Naděžda Žilková David Kubička 《Catalysis Reviews》2014,56(4):333-402
Alkylbenzenes form an important segment of petrochemical industry for the manufacture of widely used commodities and specialty products. Since the last review on this topic (8), numerous new zeolite-based catalysts have been synthesized, characterized and evaluated in various transformations of aromatic hydrocarbons. This comprehensive review covers major reactions of mono-, di-, and tri-alkylbenzenes such as disproportionation, alkylation, transalkylation, isomerization, etc., over different zeolite-based acid catalysts. During the last decade, significant progress was made in the synthesis and structure determination of novel zeolites, mesoporous single crystals, hierarchic zeolites and two-dimensional zeolites. These developments have enhanced the understanding of the role of zeolites (effects of structural type, morphology, acid sites, accessibility of acid sites, shape selectivity factors) in transformations of aromatics. In this review, the emphasis is on the influence of the type of acid sites, zeolite topology, and reaction conditions on the activity, selectivity and pathways of these reactions. Thermodynamics and reaction kinetics of transformations of aromatic hydrocarbons are also discussed. This article covers mostly literature published during the period of 2002–2013. 相似文献
4.
Camilo Castro López Xavier Lefebvre Nadège Brusselle-Dupend Marie-Hélène Klopffer Laurent Cangémi Sylvie Castagnet Jean-Claude Grandidier 《Journal of Materials Science》2016,51(8):3750-3761
This paper discusses the effect of porosity and hydrostatic pressure on diffusion kinetics and equilibrium water uptake in a semicrystalline fluoropolymer. Water sorption experiments at atmospheric pressure and under water pressures up to 250 MPa were carried out during 18 months at 40 °C on reference and porous samples. Porosity of samples was induced due to a cavitation process occurring at the highest triaxiality area of waisted and notched specimens during tensile tests. Water uptake was found to be very sensitive to porosity, showing an increase in samples with a high void fraction. On the other hand, water content decreased with increasing pressure suggesting a compaction of the porous space in which water can be stored. Two models describing this water uptake behaviour were considered. The first is a classical model which assumes that sorption occurs only by diffusion following Fick’s law. Fick’s model was found to be in agreement with the experimental results. A “Langmuir-type” sorption model was also proposed to describe water uptake in porous samples, considering a two-phase water transport mechanism: one portion of the absorbed water diffuses through the polymer matrix and the other portion is stored in voids. This model was implemented in a user subroutine using ABAQUS? software and simulations were confronted to experimental sorption curves showing satisfactory agreements. The potential of the Langmuir-type sorption model resides on its availability to be coupled to a poro-mechanical model, in order to improve the understanding of coupling between the mechanical behaviour and water sorption mechanism in a porous polymer. 相似文献
5.
<Emphasis Type="Italic">K</Emphasis>-space data processing for magnetic resonance elastography (MRE)
Nadège Corbin Elodie Breton Michel de Mathelin Jonathan Vappou 《Magma (New York, N.Y.)》2017,30(2):203-213
Objective
Magnetic resonance elastography (MRE) requires substantial data processing based on phase image reconstruction, wave enhancement, and inverse problem solving. The objective of this study is to propose a new, fast MRE method based on MR raw data processing, particularly adapted to applications requiring fast MRE measurement or high elastogram update rate.Materials and methods
The proposed method allows measuring tissue elasticity directly from raw data without prior phase image reconstruction and without phase unwrapping. Experimental feasibility is assessed both in a gelatin phantom and in the liver of a porcine model in vivo. Elastograms are reconstructed with the raw MRE method and compared to those obtained using conventional MRE. In a third experiment, changes in elasticity are monitored in real-time in a gelatin phantom during its solidification by using both conventional MRE and raw MRE.Results
The raw MRE method shows promising results by providing similar elasticity values to the ones obtained with conventional MRE methods while decreasing the number of processing steps and circumventing the delicate step of phase unwrapping. Limitations of the proposed method are the influence of the magnitude on the elastogram and the requirement for a minimum number of phase offsets.Conclusion
This study demonstrates the feasibility of directly reconstructing elastograms from raw data.6.
Rita Faddoul Nadège Reverdy-Bruas Joséphine Bourel 《Journal of Materials Science: Materials in Electronics》2012,23(7):1415-1426
The novelty of this work is laboratory formulation of environmentally friendly, water-based silver inks adapted for screen printing. The challenge was also to elaborate inks that can withstand temperatures as high as 900 °C. Indeed, when printed on ceramic substrate, they were sintered at these high temperatures. These inks can replace conductive silver pastes present in the market, today, and containing irritant solvents such as terpineol and other aromatic solvents. Besides, screen printing is considered as an additive technique, thus allowing reducing wastes. Furthermore, only with 72.5% silver, considered as low content compared to commercial inks (≥75%), prepared inks presented good electrical resistivity, 23 nΩ m, close to that of bulk silver resistivity, 16 nΩ m. Formulation of silver inks with spherical particles, 2–3 μm mean diameter, was performed. The aim of the study was to determine silver content effect on pastes rheological behaviour, lines properties (width, thickness and roughness) and electrical properties. Therefore, rheological behaviour of inks was studied; in particular, Casson and Bingham models were applied in order to determine the yield stress. Viscosity evolution as a function of shear rate was also determined. Besides, the thixotropic behaviour of inks was highlighted. Inks were then screen printed on alumina sintered substrates and cured at different temperatures during 15 min. Topography measurements were performed. Line resistivity as small as 35 nΩ m was measured on cured lines. These inks, printed on ceramic tapes, can be used to print microwave transmission lines, for which resistivities lower than 1 mΩ m are requested. 相似文献
7.
Evidence that Crystal Facet Orientation Dictates Oxygen Evolution Intermediates on Rutile Manganese Oxide 下载免费PDF全文
Hirotaka Kakizaki Hideshi Ooka Toru Hayashi Nadège Bonnet‐Mercier Kazuhito Hashimoto Ryuhei Nakamura 《Advanced functional materials》2018,28(24)
Elucidating the mechanism that differentiates the oxygen‐evolving center of photosystem II with its inorganic counterpart is crucial to develop efficient catalysts for the oxygen evolution reaction (OER). Previous studies have suggested that the larger overpotential for MnO2 catalysts under neutral conditions may result from the instability of the Mn3+ intermediate to charge disproportionation. Here, by monitoring the surface intermediates of electrochemical OER on rutile MnO2 with different facet orientations, a correlation between the stability of the intermediate species and crystal facets is confirmed explicitly for the first time. The coverage of the Mn3+ intermediate is found to be 11‐fold higher on the metastable (101) surfaces compared to (110) surfaces, leading to the superior OER activity of (101) surfaces. The difference in OER activity may result from the difference in surface electronic states of Mn3+, where interlayer charge comproportionation of Mn2+ and Mn4+ to generate two Mn3+ species is favored on (101) facets. Considering the fact that the OER enzyme accommodates Mn3+ stably during the Kok cycle, the enhanced OER activity of the rutile MnO2 catalyst with a metastable surface highlights the importance of mimicking not only the crystal structure but also the electronic structure of the targeted natural enzyme. 相似文献
8.
Petr Synek Ond?ej JašekLenka Zají?ková Bohumil DavidVít Kudrle Nadě?da Pizúrová 《Materials Letters》2011,65(6):982-984
The powder of γ − Fe2O3 nanoparticles was synthesized in microwave torch at atmospheric pressure from 0.05 sccm of Fe(CO)5 vapors in 670 sccm of argon. The optimization of the torch reactor design and deposition conditions allowed continual synthesis of γ − Fe2O3 nanoparticles at low power consumption. The synthesized powder was collected at the reactor walls and analyzed by TEM, X-ray diffraction and Raman spectroscopy without any further purification or treatment. The mean diameter of NPs, as observed by TEM, was 12 nm with a 90% confidence interval 5.5-22 nm. 相似文献
9.
10.
The void microstructure of a simulated packing of polydisperse spheres has been investigated by means of a radical Delaunay
tessellation. We have focused on creating sphere packings by mimicking processes involved in the construction of embankment
dams: the polydisperse spheres are collectively released under gravity and denser states are mainly obtained by means of shearing
cycles. This study has been performed on a narrowly graded material for four porosities ranging from 0.42 to 0.36. The void
structure is quantified in terms of probability density functions of pore and constriction sizes, cumulative distributions
and connectivity functions. We emphasize the implications of the sample construction technique on the geometric packing arrangements,
among them a well disordered medium where tetrahedra remain the most represented unit void structure. We point out that when
porosity decreases, void distributions become narrower but the initial structure is never destroyed. Nevertheless, the densification
modifies significantly the computed mean void quantities. In this study, usual geometric arrangements obtained for very dense
materials are not encountered. 相似文献