Search results for "Discrete"
showing 10 items of 2205 documents
ON-LINE CONSTRUCTION OF A SMALL AUTOMATON FOR A FINITE SET OF WORDS
2012
In this paper we describe a "light" algorithm for the on-line construction of a small automaton recognising a finite set of words. The algorithm runs in linear time. We carried out good experimental results on real dictionaries, on biological sequences and on the sets of suffixes (resp. factors) of a set of words that shows how our automaton is near to the minimal one. For the suffixes of a text, we propose a modified construction that leads to an even smaller automaton. We moreover construct linear algorithms for the insertion and deletion of a word in a finite set, directly from the constructed automaton.
Modélisation des choix d'itinéraires pédestres en milieu urbain. Approche géographique et paysagère
2006
Nowadays, on foot journeys create renewed interest as a complementary mode of transport. Indeed, local decision makers appear as willing to reduce the imbalance between different ways of transport within the cities. In the field of Geography the term ‘mobility' refers to the practice of exchanges and movements done by individuals or groups of individuals; this mobility is likely to reveal the characteristics of places and to contribute to their alteration. Among all the modes of transport, walking implies a privileged relation between persons and area they live in. As an element of the living environment used on a daily basis and eventually integrated by the prism of perception the visible …
Recursion at the crossroads of sequence modeling, random trees, stochastic algorithms and martingales
2013
This monograph synthesizes several studies spanning from dynamical systems in the statistical analysis of sequences, to analysis of algorithms in random trees and discrete stochastic processes. These works find applications in various fields ranging from biological sequences to linear regression models, branching processes, through functional statistics and estimates of risk indicators for insurances. All the established results use, in one way or another, the recursive property of the structure under study, by highlighting invariants such as martingales, which are at the heart of this monograph, as tools as well as objects of study.
On multivalued weakly Picard operators in partial Hausdorff metric spaces
2015
We discuss multivalued weakly Picard operators on partial Hausdorff metric spaces. First, we obtain Kikkawa-Suzuki type fixed point theorems for a new type of generalized contractive conditions. Then, we prove data dependence of a fixed points set theorem. Finally, we present sufficient conditions for well-posedness of a fixed point problem. Our results generalize, complement and extend classical theorems in metric and partial metric spaces.
Incitations à l’offre de prévention et préférences en médecine générale : l’apport de la méthode DCE
2012
L’objectif de cet article est de contribuer à la compréhension des préférences des médecins pour différents dispositifs, financiers ou non, susceptibles d’être implantés en France afin de favoriser la prévention en médecine de ville. La méthode du Discrete Choice Experiment (DCE) est mobilisée à travers une enquête menée auprès de 1 396 médecins qui permet d’analyser 3 390 observations. L’estimation économétrique de la fonction d’utilité des médecins est conduite dans le cadre d’un modèle Logit conditionnel, des dispositions à payer marginales sont également calculées. Nos résultats montrent que, si l’aspect financier est important dans les préférences des médecins, les aspects non financie…
SEAM PUCKERING EVALUATION METHOD FOR SEWING PROCESS
2014
The paper presents an automated method for the assessment and classification of puckering defects detected during the preproduction control stage of the sewing machine or product inspection. In this respect, we have presented the possible causes and remedies of the wrinkle nonconformities. Subjective factors related to the control environment and operators during the seams evaluation can be reduced using an automated system whose operation is based on image processing. Our implementation involves spectral image analysis using Fourier transform and an unsupervised neural network, the Kohonen Map, employed to classify material specimens, the input images, into five discrete degrees of quality…
MIGRATION OF THE HIGHLY EDUCATED: EVIDENCE FROM RESIDENCE SPELLS OF UNIVERSITY GRADUATES*
2011
We examine the inter-regional migration of university graduates from 1991 to 2003 in Finland. The results show that time matters: two-years before and during the graduation year the hazard rates of migration increase, and then decrease thereafter. Although university graduates are particularly mobile, we find that most of them do not move from their region of studies within 10 years after graduation. The out-migration, i.e., brain drain, is much higher among graduates in the more peripheral universities than in the growth centers (Helsinki in particular). Migration is also substantially more likely for those studying away from the home region than for those studying at home. peerReviewed
Extremal Irregular Digraphs
2018
A digraph is called irregular if its distinct vertices have distinct degree pairs. An irregular digraph is called minimal (maximal) if the removal of any arc (addition of any new arc) results in a non-irregular digraph. It is easily seen that the minimum sizes among irregular n-vertex whether digraphs or oriented graphs are the same and are asymptotic to (√2/3) n3/2; maximum sizes, however, are asymptotic to n2 and n2/2, respectively. Let s stand for the sum of initial positive integers, s = 1, 3, 6, . . . . An oriented graph Hs and a digraph Fs, both large (in terms of the size), minimal irregular, and on any such s vertices, s ≥ 21, are constructed in [Large minimal irregular digraphs, Op…
Refined instability estimates for some inverse problems
2022
Many inverse problems are known to be ill-posed. The ill-posedness can be manifested by an instability estimate of exponential type, first derived by Mandache [29]. In this work, based on Mandache's idea, we refine the instability estimates for two inverse problems, including the inverse inclusion problem and the inverse scattering problem. Our aim is to derive explicitly the dependence of the instability estimates on key parameters. The first result of this work is to show how the instability depends on the depth of the hidden inclusion and the conductivity of the background medium. This work can be regarded as a counterpart of the depth-dependent and conductivity-dependent stability estim…
Systematic implementation of higher order Whitney forms in methods based on discrete exterior calculus
2022
AbstractWe present a systematic way to implement higher order Whitney forms in numerical methods based on discrete exterior calculus. Given a simplicial mesh, we first refine the mesh into smaller simplices which can be used to define higher order Whitney forms. Cochains on this refined mesh can then be interpolated using higher order Whitney forms. Hence, when the refined mesh is used with methods based on discrete exterior calculus, the solution can be expressed as a higher order Whitney form. We present algorithms for the three required steps: refining the mesh, solving the coefficients of the interpolant, and evaluating the interpolant at a given point. With our algorithms, the order of…