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261.
Audrey Hohmann Gilles Grandjean Vincent Mardhel Gilles Schaefer Nicolas Desramaut 《Transactions in GIS》2013,17(1):78-95
A vehicle mobility estimator has been developed to produce decision aid maps for projecting civil or military forces on operational theatres. Based on the exploitation of classical geographical sources (e.g. digital elevation models, optical images, and vector databases) and thematic sources (e.g. climate, meteorological, pedological and land cover databases), the system computes speed maps for different kinds of vehicles moving both on‐road and off‐road. Such computations are realized through a ground‐vehicle interaction module that estimates the vehicle performance from experimental results, numerical simulations and empirical relationships. The system's architecture is built using a GIS interface that manages the data, the computation and the presentation layers. An operational version of this tool has been tested and validated on several operational theatres in France and in northern Africa. The results show good agreement between the predicted mobility performance of various vehicles and those observed on the field. A case study is presented to illustrate the mobility maps and demonstrate their relevance in the decision‐making chain depending on different climate contexts. A short application to itinerary optimization is presented as a promising future application. 相似文献
262.
Gilles Palsky 《制图学和地理信息科学》2013,40(2):189-193
ABSTRACTNearly 50 years after the publication of the first French edition of Sémiologie Graphique, Jacques Bertin’s thought is more than ever alive, in cartography as well as in various other disciplines, such as graphic design or visual data analysis. This article recalls the main elements of Bertin’s career and puts forward the salient points of his reflection on graphics. Beyond many conceptual or technical innovations, Bertin’s essential originality appears to be his attempt to propose a general framework for graphical representations. 相似文献
263.
The aim of this paper is to model numerically concrete flow inside formworks like the Lbox. For this purpose, we use a finite element method with Lagrangian integration points (FEMLIP). We are able to follow in time and space material motion with any type of material behaviour, including non‐linear and time‐dependent ones. We also can deal with free surfaces or material interfaces. Bingham's rheology is used for fresh concrete behaviour. In order to compare with experiments, we have considered three concretes (OC, HPC and SCC) with contrasted rheologies. Their yield stress is identified by experimental slump tests and also compared with the value given by a formulation concrete software. Experimental data are found to be quite close to numerical predictions. We have also made some experimental flow tests in a LBOX. We measured the flow speed and the flow shape in the final stage. The numerical modelling of these experiments is very encouraging and shows the capability of the FEMLIP using the Bingham's law to model concrete flow and filling properties. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
264.
Gilles Fontaine Elizabeth M. Green Pierre Brassard Stéphane Charpinet Pierre Chayer Malvina Billères Suzanna K. Randall Ben Dorman 《Astrophysics and Space Science》2004,291(3-4):379-386
We briefly review the recent advances that have been made on the front of pulsating subdwarf B (sdB) stars. The first family of sdB pulsators, the EC 14026 stars, was discovered a few years ago and consists of short-period (~100?200 s) p-mode variables. The second type of pulsating sdB’s consists of the PG 1716+426 stars, a group of variables showing long-period (~1 h) g-mode pulsations. The existence of the latter was first reported less than a year ago. While the two types of sdB pulsators differ markedly in their observational characteristics, we recently found a unifying property in the sense that the observed modes in these objects are excited through the same driving process, a classic kappa mechanism associated with the radiative levitation of iron in the stellar envelope. 相似文献
265.
Stéphane Charpinet Pierre Brassard Gilles Fontaine 《Astrophysics and Space Science》2004,291(3-4):395-402
Recent observational efforts and theoretical breakthroughs have encouraged the development of detailed asteroseismic analyses of rapidly oscillating sdB stars (the so-called EC14026 stars). This led to the first seismic determinations of the fundamental parameters that define the structure of EHB stars. We briefly review the current status of these analyses, discussing some of the properties of acoustic modes in EHB models that affect the asteroseismology of these stars. We then recall the basic ideas behind the method we developed in an attempt to objectively extract, from models, asteroseismic solutions suitable to any given sdB pulsator. A preliminary application of this method to the pulsating sdB star Feige 48 is also presented. 相似文献
266.
267.
Philippe Léone Charlotte Doussier-Brochard Gilles André Yves Moëlo 《Physics and Chemistry of Minerals》2008,35(4):201-206
Mn2+Sb2S4, a monoclinic dimorph of clerite, and benavidesite (Mn2+Pb4Sb6S14) show well-individualized single chains of manganese atoms in octahedral coordination. Their magnetic structures are presented
and compared with those of iron derivatives, berthierite (Fe2+Sb2S4) and jamesonite (Fe2+Pb4Sb6S14). Within chains, interactions are antiferromagnetic. Like berthierite, MnSb2S4 shows a spiral magnetic structure with an incommensurate 1D propagation vector [0, 0.369, 0], unchanged with temperature.
In berthierite, the interactions between identical chains are antiferromagnetic, whereas in MnSb2S4 interactions between chains are ferromagnetic along c-axis. Below 6 K, jamesonite and benavidesite have commensurate magnetic structures with the same propagation vector [0.5, 0, 0]:
jamesonite is a canted ferromagnet and iron magnetic moments are mainly oriented along the a-axis, whereas for benavidesite, no angle of canting is detected, and manganese magnetic moments are oriented along b-axis. Below 30 K, for both compounds, one-dimensional magnetic ordering or correlations are visible in the neutron diagrams
and persist down to 1.4 K. 相似文献
268.
The Karacadağ (Kulu-Konya) area is one of the main volcanic provinces in Central Anatolia. The Karacadağ volcanites are composed of large volumes of andesitic-dacitic lavas associated with pyroclastics and small volumes of alkali basalt, trachybasalt and trachyandesite lavas. Two groups of volcanic rocks can be distinguished: (1) calcalkaline rocks including andesites and dacites, and (2) alkaline rocks including basalts, trachybasalts and trachyandesites. 40Ar/39Ar ages show that the Karacadağ volcanites were erupted during Early Miocene (ca.18–19 Ma) and suggest that alkaline volcanites succeed shortly afterwards calcalkaline volcanites. Major oxides and trace elements plotted versus SiO2 suggest fractionation of hornblende, Fe–Ti oxide and apatite for calcalkaline volcanic rocks and olivine, clinopyroxene and Fe–Ti oxide for alkaline volcanic rocks in the magmatic evolution. The incompatible trace element patterns of the calcalkaline volcanites show enrichment of LILEs (Sr, K, Rb, Ba and Th) and negative HFSEs (Nb, Ta) anomalies suggesting an enriched lithospheric source by a subduction-related process. On the other hand, alkaline volcanites show enrichment of both LILEs and HFSEs suggesting an enriched lithospheric source by small volume melts from the asthenosphere. The rocks also have moderately fractionated REE patterns with (La/Lu)N ratios of 7–24 for calcalkaline and 6–17 for alkaline volcanites. Moreover, the volcanites have relatively low 87Sr/86Sr(t) ratios for between 0.703782 and 0.705129, and high εNd(t) values between +2.25 and +4.49. Generally, the Sr–Nd isotopic compositions of the rocks range from the mantle array to bulk earth. All of these observations and findings suggest that the calcalkaline volcanites were formed in a subduction modified orogenic setting, and the alkaline volcanites in a within-plate setting. 相似文献
269.
270.
Jackie Despriée Pierre Voinchet Hélène Tissoux Jean-Jacques Bahain Christophe Falguères Gilles Courcimault Jean Dépont Marie-Hélène Moncel Sophie Robin Marta Arzarello Robert Sala Laurent Marquer Erwan Messager Simon Puaud Salah Abdessadok 《Quaternary Science Reviews》2011,30(11-12):1474-1485
This paper records the findings from c. 80 prehistoric sites that have been discovered in the alluvial deposits of the rivers Creuse, Cher, and Loir, tributaries of the middle Loire River, over the period since 1981. These deposits comprise river terrace aggradations formed during successive glacial–interglacial cycles which have recorded climate and environment during Quaternary time. The systematic dating of these river deposits by Electron Spin Resonance (ESR) applied to optically bleached sedimentary quartz has resulted in the establishment of a chronological framework for the evolution of these rivers during Lower and Middle Pleistocene (between 1.7 Ma and 130 ka). Evidence for Early Palaeolithic (Mode 1) industries with an in situ context (workshops, soils) in the highest aggradations indicates that Hominins were present in the study area, near the geographical centre of France (47°N), around 1.1 Ma. Examination of the sites indicates that Human occupations were located along valley bottom sites during temperate episodes. Subsequently, after a gap of several hundred thousand years industries with handaxes appear in the Middle Loire Basin in the interval between 700 and 600 ka, and then continuously from 400 ka. These two phases of settlement produced industrial assemblages with clear differences in their responses to the supplies of raw materials and in the modes of making flakes. 相似文献