Search results for "formal"
showing 10 items of 1654 documents
Calculations of the atomic structure of the KNbO3 (110) surface
2000
Abstract The O-terminated KNbO 3 (110) surface is modeled using a semi-empirical shell model and two different short-range interatomic potentials. We find this surface to be unstable with respect to a strong reconstruction and K-termination. This conclusion is confirmed by preliminary calculations using the ab initio linear combination of atomic orbitals (LCAO) formalism.
In-medium pi-pi Correlation Induced by Partial Restoration of Chiral Symmetry
2000
We show that both the linear and the non-linear chiral models give an enhancement of the pi-pi cross section near the 2pi threshold in the scalar-iso-scalar (I=J=0) channel in nuclear matter. The reduction of the chiral condensate, i.e., the partial chiral restoration in nuclear matter, is responsible for the enhancement in both cases. We extract an effective 4pi-nucleon vertex which is responsible for the enhancement but has not been considered in the non-liear models for in-medium pi-pi interaction. Relation of this vertex and a next-to-leading order terms in the heavy-baryon chiral lagrangian, L_piN^(2), is also discussed.
Form factors of the isovector scalar current and the ηπ scattering phase shifts
2015
33 pages.- 14 figures.- v2: Some clarifications and corrections of typos
Implementation of local chiral interactions in the hyperspherical harmonics formalism
2021
With the goal of using chiral interactions at various orders to explore properties of the few-body nuclear systems, we write the recently developed local chiral interactions as spherical irreducible tensors and implement them in the hyperspherical harmonics expansion method. We devote particular attention to three-body forces at next-to-next-to leading order, which play an important role in reproducing experimental data. We check our implementation by benchmarking the ground-state properties of $^3$H, $^3$He and $^4$He against the available Monte Carlo calculations. We then confirm their order-by-order truncation error estimates and further investigate uncertainties in the charge radii obta…
Apport d'un formalisme psychologique à la modélisation des préférences individuelles. Application aux choix d'itinéraires pédestres
2007
With the increasing need for a sustainable mobility, pedestrian movement analysis lately increased. In an attempt to get a more detailed knowledge of urban pedestrian movement, we intend to model the pedestrian's route choices. Our first approach is based on simple economic models, the discrete choice models. A psychological theory is added in the process in order to improve the pedestrian behaviour simulation. Results show that psychological formalisms are useful for individual choices' modelling. For this reason they could be used more systematically in the framework of urban mobility
Visible-light driven oxidation of gaseous aliphatic alcohols to the corresponding carbonyls via TiO2 sensitized by a perylene derivative
2013
Sensitized P25 TiO2 was prepared by wet impregnation with a home-prepared perylene dye, i.e., N,N?-bis(2-(1- piperazino)ethyl)-3,4,9,10-perylene-tetracarboxylic acid diimide dichloride (PZPER). Energy levels of PZPER were found to be compatible with those of TiO2 allowing fast electron transfer. The obtained catalyst has been characterized and used in the gas-phase partial oxidation of aliphatic primary and secondary alcohols, i.e., methanol, ethanol, and 2- propanol. The reaction was carried out under cut-off (?> 400 nm) simulated solar radiation in O2 atmosphere. The perylene derivative allowed a good absorbance of visible radiation thanks to its low optical energy gap (2.6 eV) which was …
Raons essencials i creença
2003
In this paper I defend that what I call modes of denotation are part of one¿s belief content, even if they are not part of the proposition expressed by the sentence one believes to be true. Two people, who believe of the same sentence (not ambiguous) that it is true can have different belief contents that they express by means of this same sentence.
Comprehending city and its production in Africa through a systemic approach : example of the city of Diamniadio, Dakar
2022
For a long time, the analysis of the production of the city in Africa was based on an exogenous perception according to urban models theorized and experimented with in the Occidental countries, then diffused and applied through different mechanisms in the South, bearing witness to historical relations - through the making of the colonial city - and present relations - in the context of the making of new towns. After independence, researchers looked at the redefinition of the city in Africa with its complexity and plurality according to geographical and historical trajectories, proposing new urban theories that were more nuanced and linked to local and contextual realities. Therefore, follow…
Media Literacy in I taly
2019
In Italy, the media literacy (ML) movement has a long grassroots tradition. Main actors are from civil society (academics, associations, church communities, teachers, media professionals, educators), with some growing support from local and national institutions. While digital literacy has stably entered the school system through funds, projects, and teaching resources aimed at improving students' digital skills, only recently has a more sociocultural view of digital technologies developed, thanks also to the National Plan for Digital School issued by the Ministry of Education in 2015. For the future, more commitment to developing the following three important directions is needed: conducti…
Context-free Languages
1988
In this chapter we shall define a class of rewriting systems called context-free grammars. The left-hand side of a rule in a context-free grammar consists of a single symbol, so that symbols are rewritten “context-freely”. Context-free grammars are of central importance to us because they define the class of context-free languages, the parsing of which is the subject of this book. In this chapter we shall consider some structural properties of context-free grammars which are of importance in parsing. Also, a basic method for recognizing context-free languages will be given.