Search results for "Mali"
showing 10 items of 3900 documents
Optimality results in orbit transfer
2007
Abstract The objective of this Note is to present optimality results in orbital transfer. Averaging of the energy minimization problem is considered, and properties of the associated Riemannian metric are discussed. To cite this article: B. Bonnard, J.-B. Caillau, C. R. Acad. Sci. Paris, Ser. I 345 (2007).
Symmetry-adapted tensorial formalism to model rovibrational and rovibronic spectra of molecules pertaining to various point groups
2004
International audience; We present a short review on the tensorial formalism developed by the Dijon group to solve molecular spectroscopy problems. This approach, originally devoted to the rovibrational spectroscopy of highly symmetrical species (spherical tops) has been recently extended in several directions: quasi-spherical tops, some symmetric and asymmetric tops, and rovibronic spectroscopy of spherical tops in a degenerate electronic state. Despite its apparent complexity (heavy notations, quite complex mathematical tools), these group theoretical tensorial methods have a great advantage of flexibility: a systematic expansion of effective terms for any rovib- rational/rovibronic probl…
Timing and patterns of ENSO impacts in Africa over the last 30 years: insights from Normalized Difference Vegetation Index data.
2012
International audience; In this study we reassess and provide a more complete picture of the timing and patterns of ENSO impacts for the whole of Africa over the three last decades. We analyse the vegetation photosynthetic activity estimated by the NOAA-AVHRR Normalized Difference Vegetation Index (NDVI) rather than rainfall itself, because NDVI allows us to document the impacts at fine space and time scales. The use of the monthly time-step adds important new insights to the findings of previous works based largely on annual or seasonal time-scales and on a regional spatial-scale: several dipolar and propagative patterns are highlighted. In addition, we show that the less-studied winter ra…
High-resolution far-infrared synchrotron FTIR spectroscopy and analysis of the ν 7 , ν 19 and ν 20 bands of trioxane
2022
Rovibrational bands spectra of three ν20, ν7 and ν19 bands of 1, 3, 5 – trioxane (H2CO)3 were recorded in the 50–650 cm−1 range using a long path absorption cell coupled to a high resolution Fourier transform spectrometer and synchrotron radiation at the AILES beamline of the SOLEIL synchrotron. More than 16 000 lines were assigned with a dRMS better than 0.17 × 10−3 cm−1. Two different formalisms (tensorial and Watson) were used to derive accurate rotational and quartic parameters for the three bands and for the first time, a precise determination of Coriolis parameter and q+ l−doubling constant for both ν20 and ν19 perpendicular bands was obtained. Last, each set of spectroscopic paramete…
Semantics knowledge management for the 3D architectural reconstruction of building objects
2010
International audience; This paper presents the framework of an ongoing semantics knowledge management practice. The practice combines geometrical analysis of point cloud and semantic rules to detect 3D building objects for the purpose of achieving computational correctness and efficiency. We assume that improvement in the form of well organized classification (CLA) and order (ORD) is a solution. Statically related knowledge is classified as definition, partial knowledge and ambiguous knowledge and formally revealed with transitions between CWA (closed world assumption) and OWA (open world assumption). To achieve the correctness, formalization is proposed for the validation of the rules thr…
Managing semantics knowledge for 3D architectural reconstruction
2010
International audience; this work aims at bound geometrical detection of 3D objects from a point cloud using semantic descriptors to improve reusability of architectural building reconstruction and aid automatic reasoning in building information modeling (BIM). Based on exploring cognitive origins of spatial semantics representations, semantics conceptualization and classification is proposed for formal management of 3D architectural objects. The knowledge classification composes definition, partial knowledge and ambiguous knowledge, and is formalized with transformations among closed world assumption (CWA) and open world assumption (OWA). Systemic case study is conducted on a simplified bu…
Formalizing Semantic of Natural Language through Conceptualization from Existence
2011
International audience; We propose an outline of an approach to formalize semantic from conceptualization for both natural language (NL) and logic expression mechanisms. This goes beyond the level of discussions at conceptual level which has to either end in conscious/unconscious relativity of understanding or subjective enforcement in the form of definitions instead of expected objective semantic. This approach supports to view from a pure mathematical perspective, and explore and locate the fundamental problems. The semantic formalization mechanism realizes the integration of problem description and the solution expression at absolute semantic level. So a problem describing process is equ…
COBieOWL, an OWL ontology based on COBie standard
2015
International audience; Building Information Modelling (BIM) standards have been recognized by construction and political actors as a highly promising tool for resolving issues of data dematerialization, notably in the field of Architecture, Engineering, Construction and Facility Management. Among worldwide-adopted BIM standards, there is COBie. COBie’s goals are to dematerialize building data and to enhance building information interoperability. Nevertheless, COBie data is available in static formats such as STEP or spreadsheet templates. Such formats lack logical formalisms and semantic features provided by languages such as OWL. Because of this, in this paper, we propose a method for sem…
Collective excitations of 3He clusters
1991
Collective excitations of3He clusters are studied by treating the cluster as a quantum liquid drop. We have used the Random-Phase Approximation sum rules technique within a Density Functional Formalism. Results forL=2 to 10 surface modes and theL=0 volume mode are presented.