Search results for " Computer Science"

Lambda Architecture pour une analyse à haute performance des données des réseaux sociaux

2019

In this article, we show how a Lambda Architecture can contribute to the development of a platform for collecting and analyzing, in real-time, data from Twitter. After having presented the context, detailed the needs and identified the expected specificities, we compare the Lambda and Kappa architectures and we describe the state of the art on Lambda Architecture use in different domains. We propose an adaptation of the Lambda architecture to allow the storage of data in a polystore and to take into account different types of analysis to be carried out to answer researches in social sciences and communication sciences. In these projects the objectives are to study the structure of communica…

Virtual reality for driving simulation

1996

In this paper, the authors describe the data structure necessary to provide real time simulation and visualization of complex environments and situations. Through the SIRCA project, the development of driving oriented simulators, using Virtual Reality (VR) and evaluating it in comparison with convention technologies, has taken place. Focus is on some of the algorithms and data structure required to provide real time simulation of the complex urban environment and its visualization under the conditions of VR devices.

Cancellation, pumping and permutation in formal languages

1984

A syntax controlled generator of formal language processors

1963

Foundations for the formalization of metamathematics and axiomatizations of consequence theories

2004

Abstract This paper deals with Tarski's first axiomatic presentations of the syntax of deductive system. Andrzej Grzegorczyk's significant results which laid the foundations for the formalization of metalogic, are touched upon briefly. The results relate to Tarski's theory of concatenation, also called the theory of strings, and to Tarski's ideas on the formalization of metamathematics. There is a short mention of author's research in the field. The main part of the paper surveys research on the theory of deductive systems initiated by Tarski, in particular research on (i) the axiomatization of the general notion of consequence operation, (ii) axiom systems for the theories of classic conse…

Espaces tangents pour les formes auto-similaires

2013

The fractal geometry is a relatively new branch of mathematics that studies complex objects of non-integer dimensions. It finds applications in many branches of science as objects of such complex structure often poses interesting properties. In 1988 Barnsley presented the Iterative Func-tion System (IFS) model that allows modelling complex fractal shapes with only a limited set of contractive transformations. Later many other models were based on the IFS model such as Language-Restricted IFS,Projective IFS, Controlled IFS and Boundary Controlled IFS. The lastto allow modelling complex shapes with control points and specific topol-ogy. These models cover classical geometric models such as B-…

The Intersection of $3$-Maximal Submonids

2020

Very little is known about the structure of the intersection of two $k$-generated monoids of words, even for $k=3$. Here we investigate the case of $k$-maximal monoids, that is, monoids whose basis of cardinality $k$ cannot be non-trivially decomposed into at most $k$ words. We characterize the intersection in the case of two $3$-maximal monoids.

Design of a Programmable and Modular Neuromuscular Electrical Stimulator Integrated Into a Wireless Body Sensor Network

2021

Neuromuscular electrical stimulation finds application in several fields, from basic neurophysiology, to motor rehabilitation and cardiovascular conditioning. Despite the progressively increasing interest in this technique, its State-of-the-Art technology is mainly based on monolithic, mostly wired devices, leading to two main issues. First, these devices are often bulky, limiting their usability in applied contexts. Second, the possibility of interfacing these stimulation devices with external systems for the acquisition of electrophysiological and biomechanical variables to control the stimulation output is often limited. The aim of this work is to describe the design and development of a…

MLOG: a strongly typed confluent functional language with logical variables

1994

Poirriez, V., MLOG: a strongly typed confluent functional language with logical variables, Theoretical Computer Science 122 (1994) 201-223. A new programming language called MLOG is introduced. MLOG is a conservative extension of ML with logical variables. To validate our concepts, a compiler named CAML Light FLU0 was implemented. Numerous examples are presented to illustrate the possibilities of MLOG. The pattern matching of ML is kept for X-calculus bindings and an unification primitive is introduced for the logical variables bindings. A suspension mechanism allows cohabitation of pattern-matching and logical variables, Although the evaluation strategy for the application is fixed, the or…

Textureless macula swelling detection with multiple retinal fundus images

2011

Retinal fundus images acquired with nonmydriatic digital fundus cameras are versatile tools for the diagnosis of various retinal diseases. Because of the ease of use of newer camera models and their relatively low cost, these cameras can be employed by operators with limited training for telemedicine or point-of-care (PoC) applications. We propose a novel technique that uses uncalibrated multiple-view fundus images to analyze the swelling of the macula. This innovation enables the detection and quantitative measurement of swollen areas by remote ophthalmologists. This capability is not available with a single image and prone to error with stereo fundus cameras. We also present automatic alg…