3,806 research outputs found
Multivariate Hawkes Processes for Large-scale Inference
In this paper, we present a framework for fitting multivariate Hawkes
processes for large-scale problems both in the number of events in the observed
history and the number of event types (i.e. dimensions). The proposed
Low-Rank Hawkes Process (LRHP) framework introduces a low-rank approximation of
the kernel matrix that allows to perform the nonparametric learning of the
triggering kernels using at most operations, where is the
rank of the approximation (). This comes as a major improvement to
the existing state-of-the-art inference algorithms that are in .
Furthermore, the low-rank approximation allows LRHP to learn representative
patterns of interaction between event types, which may be valuable for the
analysis of such complex processes in real world datasets. The efficiency and
scalability of our approach is illustrated with numerical experiments on
simulated as well as real datasets.Comment: 16 pages, 5 figure
Technology
The paper summarizes recent break-through in the anthropology of material culture, objects, techniques. It explains the main fields of the discipline and its evolution. A large section is about examples of field study in Papua New Guinea. Another one exposes the basic field methods to collect ethnographical data in cultural technology
Auto-anthropology, Modernity and Automobiles
Pour les collectionneurs d'automobiles "classiques", ces voiture et leurs modèles réduits fonctionnent comme des résonateurs mêlant dans l'esprit de l'acteur divers aspects de la culture automobile d'une façon qui participe à la production d'un imaginaire partagé
Fangio, Rozanoff et l'Espadon. A propos d'objets et d'imaginaires partagés
Anthropologie et histoire des rapports des baby-boomers avec les automobiles, notamment de compétition. Dimension cognitive des pratiques matérielles et mémorielles
Arcs, flèches et orgue électrique. A propos de modernité et d'offensives évangéliques dans la vallée de Wonenara (Papouasie Nouvelle-Guinée)
International audienceL'avancée des églises évangéliques dans la lointaine vallée de Wonenara (Papouasie) est incompréhensible hors du contexte historique des événements qui ont suivi le premier contact avec cette population, en 1951: transformation des initiations masculines, paix forcés avec les groupes voisins, présence ancienne des Luthériens, modernité et économie du café
On the structure of framed vertex operator algebras and their pointwise frame stabilizers
In this paper, we study the structure of a general framed vertex operator
algebra. We show that the structure codes (C,D) of a framed VOA V satisfy
certain duality conditions. As a consequence, we prove that every framed VOA is
a simple current extension of the associated binary code VOA V_C. This result
would give a prospect on the classification of framed vertex operator algebras.
In addition, the pointwise frame stabilizer of V is studied. We completely
determine all automorphisms in this pointwise stabilizer, which are of order 1,
2 or 4. The 4A-twisted sector and the 4A-twisted orbifold theory of the famous
Moonshine VOA are also constructed explicitly. We verify that the top module of
this twisted sector is of dimension 1 and of weight 3/4 and the VOA obtained by
4A-twisted orbifold construction of the moonshine VOA is isomorphic to the
moonshine VOA itself.Comment: Version 3: 59 pages. Corrected version. 54 pages on my LaTeX system
version 2: We add Theorem 5.16 in which we give a necessary and sufficient
condtion for a code to be a structure code of a holomorphic framed VOA.
"hyperref" style is also introduce
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