Fast Lexically Constrained Viterbi Algorithm (FLCVA): Simultaneous Optimization of Speed and Memory

Lexical constraints on the input of speech and on-line handwriting systems improve the performance of such systems. A significant gain in speed can be achieved by integrating in a digraph structure the different Hidden Markov Models (HMM) corresponding to the words of the relevant lexicon. This integration avoids redundant computations by sharing intermediate results between HMM's corresponding to different words of the lexicon. In this paper, we introduce a token passing method to perform simultaneously the computation of the a posteriori probabilities of all the words of the lexicon. The coding scheme that we introduce for the tokens is optimal in the information theory sense. The tokens use the minimum possible number of bits. Overall, we optimize simultaneously the execution speed and the memory requirement of the recognition systems.Comment: 5 pages, 2 figures, 4 table

On the binding of N-acetylglucosamine and chitobiose to hen lysozyme in the solid state at high temperature

Copyright © 1979 Published by Elsevier Science B.V. All rights reserved.This paper deals with the crystallization of lysozyme at 40°C and 50°C in the presence of GlcNAc or chitobiose

A Kernel for Protein Secondary Structure Prediction

http://mitpress.mit.edu/catalog/item/default.asp?ttype=2&tid=10338&mode=tocInternational audienceMulti-class support vector machines have already proved efficient in protein secondary structure prediction as ensemble methods, to combine the outputs of sets of classifiers based on different principles. In this chapter, their implementation as basic prediction methods, processing the primary structure or the profile of multiple alignments, is investigated. A kernel devoted to the task is introduced, which incorporates high-level pieces of knowledge. Initial experimental results illustrate the potential of this approach

Strain state in single quantum well GaAs/1ML-InAs/GaAs(100) analysed by high-resolution X-ray diffraction

dépôt d'une copie effectué avec l'aimable autorisation de EDP SciencesThe epitaxy-induced tetragonal strain in one monolayer of InAs buried in a GaAs(100) crystal is determined by measuring weak oscillations in X-ray reflectivity profiles. It is shown that the reflectivity of such heterostructure consists of a sinusoidal modulation of the usual rocking curve of a thick crystal. The oscillation period provides the distance of the buried layer from the crystal surface and the maximum positions in oscillations give the displacement induced by the buried layer. The vertical spacing between the In and As atom planes is found to be 1.64 ± 0.02 Å, which is consistent with an elastic behaviour

Geometrical structure of an iron epilayer on Si (111) : an X-ray standing wave analysis

dépôt d'une copie effectué avec l'aimable autorisation de EDP SciencesThe structure of an iron film, deposited at low temperature (50 °C) upon a silicon (111) substrate, has been determined by means of X-ray Standing Wave experiments performed at LURE (Orsay, France). Experimental results are coherent with the model of an abrupt interface between the adsorbate and the surface : the first site of adsorption terminates the bulk silicon and a body-centred iron layer epitaxially grows on the substrate with a preferential growth orientation

Effect of Tuned Parameters on a LSA MCQ Answering Model

This paper presents the current state of a work in progress, whose objective is to better understand the effects of factors that significantly influence the performance of Latent Semantic Analysis (LSA). A difficult task, which consists in answering (French) biology Multiple Choice Questions, is used to test the semantic properties of the truncated singular space and to study the relative influence of main parameters. A dedicated software has been designed to fine tune the LSA semantic space for the Multiple Choice Questions task. With optimal parameters, the performances of our simple model are quite surprisingly equal or superior to those of 7th and 8th grades students. This indicates that semantic spaces were quite good despite their low dimensions and the small sizes of training data sets. Besides, we present an original entropy global weighting of answers' terms of each question of the Multiple Choice Questions which was necessary to achieve the model's success.Comment: 9 page

An Optimal Path Coding System for DAWG Lexicon-HMM

Lexical constraints on the input of speech and on-line handwriting systems improve the performance of such systems. A significant gain in speed can be achieved by integrating in a digraph structure the different Hidden Markov Models (HMM) corresponding to the words of the relevant lexicon. This integration avoids redundant computations by sharing intermediate results between HMM's corresponding to different words of the lexicon. In this paper, we introduce a token passing method to perform simultaneously the computation of the a posteriori probabilities of all the words of the lexicon. The coding scheme that we introduce for the tokens is optimal in the information theory sense. The tokens use the minimum possible number of bits. Overall, we optimize simultaneously the execution speed and the memory requirement of the recognition systems

Réduction de moitié du volume mémoire et de la durée de calcul dans l'usage des algorithmes de transformation de Fourier rapide (FFT)

Copyright © International Union of CrystallographyAfter a brief review of the crystallographic Fourier transform problem, this paper compares three methods for its computer implementation with reference to core-storage capacity and computation time: the classic method, the simple Fast Fourier Transform algorithms and a new method. The first method needs, especially for a macromolecular three-dimensional structure, too many operations and therefore too long a computation time and poor accuracy. The remarkable FFT algorithm, on the other hand, leads to large savings in computation time with a better accuracy, but using no crystallographic symmetry wastes too much storage capacity. The third method, using FFT but taking into account Friedel's law by means of a simple in situ process, approximately halves the storage capacity as well as the computation time

Crystallographic statistics (progress and problems). Edited by S. Ramaseshan, M.F. Richardson & A.J.C. Wilson (1982)

Lifchitz Alain. Crystallographic statistics (progress and problems). Edited by S. Ramaseshan, M.F. Richardson & A.J.C. Wilson (1982). In: Bulletin de Minéralogie, volume 107, 5, 1984. p. 702

Transformation de Fourier Discrète et Calculs Radiocristallographiques

mention: Sciences PhysiquesApplication of Fast Fourier Transform (FFT) algorithms to radiocrystallographic computations.Application aux calculs radiocristallographiques des algorithmes de transformation de Fourier rapide (Fast Fourier Transform (FFT))