Search results for "quantitative"
showing 10 items of 2409 documents
Introduction aux théories et aux méthodes de la mesure en sciences psychologiques et en sciences de l'éducation
2004
La méthode des vignettes expérimentales : applications aux questions de discriminations
2021
Cette présentation vise à décrire les caractéristiques et les spécificités de la méthode des vignettes expérimentales appliquée aux questions de discrimination en économie. Cette méthode permet de préciser les positions normatives d’un échantillon représentatif d’individus à l’égard de ces comportements prohibés par la loi et d’identifier les éléments qui influencent leurs positions : la nature et les conséquences de la discrimination, le coût d’un comportement non discriminatoire, l’environnement social, le comportement des autres agents. Les résultats issus de trois campagnes de vignettes menées entre 2018 et 2021 seront exposés pour illustrer cette présentation. Elles portent sur les élé…
Graph-based exploration and clustering analysis of semantic spaces
2019
Abstract The goal of this study is to demonstrate how network science and graph theory tools and concepts can be effectively used for exploring and comparing semantic spaces of word embeddings and lexical databases. Specifically, we construct semantic networks based on word2vec representation of words, which is “learnt” from large text corpora (Google news, Amazon reviews), and “human built” word networks derived from the well-known lexical databases: WordNet and Moby Thesaurus. We compare “global” (e.g., degrees, distances, clustering coefficients) and “local” (e.g., most central nodes and community-type dense clusters) characteristics of considered networks. Our observations suggest that …
Statistically validated networks in bipartite complex systems.
2011
Many complex systems present an intrinsic bipartite nature and are often described and modeled in terms of networks [1-5]. Examples include movies and actors [1, 2, 4], authors and scientific papers [6-9], email accounts and emails [10], plants and animals that pollinate them [11, 12]. Bipartite networks are often very heterogeneous in the number of relationships that the elements of one set establish with the elements of the other set. When one constructs a projected network with nodes from only one set, the system heterogeneity makes it very difficult to identify preferential links between the elements. Here we introduce an unsupervised method to statistically validate each link of the pr…
Diffusive neural network
2002
Abstract A non-connectionist model of a neuronal network based on passive diffusion of neurotransmitters is presented as an alternative to hard-wired artificial neural networks. Classic thermodynamical approach shows that the diffusive network is capable of exhibiting asymptotic stability and a dynamics resembling that of a chaotic system. Basic computational capabilities of the net are discussed based on the equivalence with a Turing machine. The model offers a way to represent mass-sustained brain functions in terms of recurrent behaviors in the phase space.
The computational power of continuous time neural networks
1997
We investigate the computational power of continuous-time neural networks with Hopfield-type units. We prove that polynomial-size networks with saturated-linear response functions are at least as powerful as polynomially space-bounded Turing machines.
Some Afterthoughts on Hopfield Networks
1999
In the present paper we investigate four relatively independent issues, which complete our knowledge regarding the computational aspects of popular Hopfield nets. In Section 2 of the paper, the computational equivalence of convergent asymmetric and Hopfield nets is shown with respect to network size. In Section 3, the convergence time of Hopfield nets is analyzed in terms of bit representations. In Section 4, a polynomial time approximate algorithm for the minimum energy problem is shown. In Section 5, the Turing universality of analog Hopfield nets is studied. peerReviewed
Secret versus public reserve price in an “outcry” English procurement auction: Experimental results
2015
Abstract In a set of human experiments, we analyze the impact of the buyer׳s reserve price policy in an online open outcry reverse auction. We measure the impact of revealing or not the reserve price on the buyer׳s expected cost when suppliers may be risk-averse. Results confirm that the optimal public reserve price policy dominates for the buyer when the lowest cost supplier is weakly risk-averse but in contrast with theory, the secret reserve price policy does not dominate when he becomes very risk-averse. Analysis of strategic suppliers׳ bidding behavior shows, in conformity with theory, that they react to the secret reserve price and are more aggressive when they are more risk-averse. T…
A remark on hyperplane sections of rational normal scrolls
2017
We present algebraic and geometric arguments that give a complete classification of the rational normal scrolls that are hyperplane section of a given rational normal scrolls.
Computer Simulation Studies of Chain Dynamics in Polymer Brushes
2012
Center-of-mass and single monomer motion in grafted chains comprising a strongly stretched polymer brush in thermal equilibrium are studied by large scale molecular dynamics and Monte Carlo simulations of a coarse-grained model. Good solvent conditions are assumed. Our findings seriously question earlier theoretical predictions about the relaxation described by Rouse dynamics of brush coatings. Thus, the correlation functions of parallel and perpendicular components of the mean distance of the center-of-mass from the grafting site, the squared gyration radius and end-to-end distance, are found to deviate strongly from a simple exponential decay. While the relaxation times extracted from the…