Search results for " Computer Science"
showing 10 items of 3983 documents
Numerical simulation of unsteady MHD flows and applications
2009
International audience; We present a robust numerical method for solving the compressible Ideal Magneto-Hydrodynamic equations. It is based on the Residual Distribution (RD) algorithms already successfully tested in many problems. We adapted the scheme to the multi-dimensional unsteady MHD model. The constraint ∇ · B = 0 is enforced by the use a Generalized Lagrange Multiplier (GLM) technique. First, we present this complete system and the keys to get its eigensystem, as we may need it in the algorithm. Next, we introduce the numerical scheme built in order to get a compressible, unsteady and implicit solver which has good shock-capturing properties and is second-order accurate at the conve…
On identification of separable kernel systems
1979
An identification procedure for special separable kernel systems is presented. The suitable definition of adequateness of a signal leads to a systematic treatment of the choice of inputs for identification.
Polysemy and gestaltist computation. some notes on gestaltist compositionality
2019
The paper is devoted to the concept of Gestaltist Compositionality. It is divided into two parts. The first part will introduce a minimal definition of «Gestaltist Compositionality». Moreover, it will prove that the computations implemented by this model of compositionality are sufficiently flexible to ensure the presence of several orders of semantic determination. The second part will be devoted to an investigation of the consequences of this result with particular reference to the identification of some versions of compositionality which relax the condition of semantic atomism without weakening the links of determination between understanding of the compounds and understanding of the com…
INDUCTIVE INFERENCE OF LIMITING PROGRAMS WITH BOUNDED NUMBER OF MIND CHANGES
1996
We consider inductive inference of total recursive functions in the case, when produced hypotheses are allowed some finite number of times to change “their mind” about each value of identifiable function. Such type of identification, which we call inductive inference of limiting programs with bounded number of mind changes, by its power lies somewhere between the traditional criteria of inductive inference and recently introduced inference of limiting programs. We consider such model of inductive inference for EX and BC types of identification, and we study • tradeoffs between the number of allowed mind changes and the number of anomalies, and • relations between classes of functions ident…
Dual types of hypotheses in inductive inference
2006
Several well-known inductive inference strategies change the actual hypothesis only when they discover that it “provably misclassifies” an example seen so far. This notion is made mathematically precise and its general power is characterized. In spite of its strength it is shown that this approach is not of “universal” power. Consequently, then hypotheses are considered which “unprovably misclassify” examples and the properties of this approach are studied. Among others it turns out that this type is of the same power as monotonic identification. Finally, it is shown that “universal” power can be achieved only when an unbounded number of alternations of these dual types of hypotheses is all…
Topological considerations in composing teams of learning machines
1995
Classes of total recursive functions may be identifiable by a team of strategies, but not by a single strategy, in accordance with a certain identification type (EX, FIN, etc.). Qualitative aspects in composing teams are considered. For each W ∉ EX all recursive strategies can be split into several families so that any team identifying W contains strategies from all the families. For W ∉ FIN the possibility of such splitting depends upon W. The relation between these phenomena and “voting” properties for types EX, FIN, etc. is revealed.
Methods for Experimentally Determining Stiffness of a Multi-Axis Machining Centre
2019
This paper deals with global methods for experimentally determining the static stiffness of multi-axis machining centres. Different devices used for measuring deflection, in specific, are explored, where accuracy and usability are highlighted. The methods were tested on a 3-axis CNC milling machine, 2-axis trunnion table and a 6-DOF industrial robot.
Identification and validation of quasispecies models for biological systems
2009
An identification procedure for biological systems cast as quasi-species models is proposed. Their identification is a challenging problem because of the bilinear dependence on the parameters and their physical constraints. The proposed solution is within the framework of set-membership identification. %The bilinear dependence on parameters of the model and their physical constraints make the present issue challenging. We determine an estimate of the model parameters together with their interval of variability (Uncertainty Intervals), taking into account all the physical constraints. Invalidation/validation is performed on the basis of the predictive capability of the estimated models. The …
Model Identification of a Network as Compressing Sensing
2013
In many applications, it is important to derive information about the topology and the internal connections of dynamical systems interacting together. Examples can be found in fields as diverse as Economics, Neuroscience and Biochemistry. The paper deals with the problem of deriving a descriptive model of a network, collecting the node outputs as time series with no use of a priori insight on the topology, and unveiling an unknown structure as the estimate of a "sparse Wiener filter". A geometric interpretation of the problem in a pre-Hilbert space for wide-sense stochastic processes is provided. We cast the problem as the optimization of a cost function where a set of parameters are used t…
Chaînage de bases de données anonymisées pour les études épidémiologiques multicentriques nationales et internationales : proposition d'un algorithme…
2009
Background: Compiling individual records coming from different sources is very important for multicenter epidemiological studies; however, European directives and other national legislation concerning nominal data processing must be respected. These legal aspects can be satisfied by implementing mechanisms that allow anonymization of patient data (such as hashing techniques). Moreover, for security reasons, official recommendations suggest using different cryptographic keys in combination with a cryptographic hash function for each study. Unfortunately, this type of anonymization procedure is in contradiction with common requirements in public health and biomedical research because it becom…