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International audience; This paper deals with the extraction of the hedgerow and copse network from hyperspectral images acquired with the Compact Airborne Spectrographic Imager (CASI). The strategy of segmentation integrates several levels of data fusion allowing a decision to be taken concerning the membership of each pixel to the hedgerow and copse network from the large set of original data. The first level leads to quantifying the membership of each pixel to specific features of the network. It includes data fusion based on physical properties, geometric context-dependent fuzzy fusion with an original consistency measure and the geometric fusion of decisions. The second level is a fuzzy fusion of methods allowing the membership of each pixel to the network to be quantified. Finally, the third level involves post-processing the data with a context-dependent fusion of decisions to obtain the final map of the hedgerow and copse network.

International audience; In this paper we propose an optimized transmission system for still images. This system comprises a VQ source encoder with a compression rate of 9. The source data is encoded using a BCH product code and mapped on a 16-QAM constellation. The codebook and channel encoder have been optimized to minimize distortion in presence of transmission errors. We use a new joint source-channel turbo decoding algorithm of the product code. As compared to classical channel decoding algorithms (soft decoding), we obtain an improvement of 0.7 dB in terms of coding gain for a BER of 10/sup -5/. The PSNR of the received image exhibits an improvement of 11 dB as compared to conventional turbo decoding at low SNRs.

cote interne IRCAM: Helie99b; National audience; In this paper, we deal with the inversion of a physical model of a trumpet, i.e. how should the model be controled in order to obtain a given sound. It is shown that this problem is ill-posed since an infinity of inputs can produce the same sound. Then, a criterion based on the slowness of the musician's gestures compared to the sound signal evolution is used: this leads to a physically pertinent solution. Finally, we present some simulation results.

The future Internet networks are expected to use IPv6 version rather than the IPv4 one. This is mainly due to the limitations of IPv4 in terms of addresses, routing and security QoS issues developed by the Internet community are also tailored for both versions and will be easily deployed in both sides. Since a huge amount of sub-networks are already installed for the v4 version, it is difficult to imagine ISPs starting deploying the v6 version without some assurance that old legacy networks will still be able to connect to the Internet. In this paper we present some mechanisms that have been proposed to ease this transition especially for v4 users that still want to communicate with their old applications. We present also an IPv6 tunneling mechanism that has some advantages over the other models. We show how one could use such a mechanism to transparently establish hybrid communications between two worlds in both ways and discuss some important issues like scalability and performance.

We submit a method (EMPI: Evaluation of Multimedia, Pedagogical and Interactive software) to evaluate multi-media software used in educational context. Our purpose is to help users (teachers or students) to decide in front of the large choice of software actually proposed. We struc-tured a list of evaluation criteria, grouped through six ap-proaches: the general feeling, the technical quality, the usability, the scenario, the multimedia documents, and the didactical aspects. A global questionnaire joins all this modules. We are also designing software that could make the method easier to use and more powerful. We present in this paper the list of the criteria we selected and organ-ised, along with some examples of questions, and a brief description of the method and the linked software.

The pitch of a periodic sound is strongly correlated with its period. To perceive the multiple pitches evoked by several simultaneous sounds, the auditory system must estimate their periods. This paper proposes a process in which the periodic sounds are canceled in turn (multistep cancellation model) or simultaneously (joint cancellation model). As an example of multistep cancellation, the pitch perception model of Meddis and Hewitt, 1991a , Meddis and Hewitt, 1991b can be associated with the concurrent vowel identification model of Meddis and Hewitt (1992) . A first period estimate is used to suppress correlates of the dominant sound, and a second period is then estimated from the remainder. The process may be repeated to estimate further pitches, or else to recursively refine the initial estimates. Meddis and Hewitt's models are spectrotemporal (filter channel selection based on temporal cues) but multistep cancellation can also be performed in the spectral or time domain. In the joint cancellation model, estimation and cancellation are performed together in the time domain: the parameter space of several cascaded cancellation filters is searched exhaustively for a minimum output. The parameters that yield this minimum are the period estimates. Joint cancellation is guaranteed to find all periods, except in certain situations for which the stimulus is inherently ambiguous.

International audience; This paper presents several techniques of traffic management such as credit-based and rate-based approaches. An example of these techniques is the simple Leaky Bucket, which is a congestion preventive method, that can easily be implemented. The Adaptive Leaky Bucket algorithm introduces a feed-back mechanism, compared to the common Leaky Bucket, in order to be more flexible and efficient. We focus our study on this algorithm in order to implement it, using a VHDL-based methodology. The design flow starts from an architectural description in RTL level in order to interact easily with current commercial hardware synthesis tools. After simulation and synthesis steps, implementation can be achieved using an ASIC or Xilinx FPGAs.

This paper presents a new method to simulate and optimize microwave amplifiers more quickly. We present the results obtained for a low-noise microwave amplifier designed according to this method. At present, in order to design a microwave amplifier it is first necessary to choose the correct type of transistor in function of the applications required. After this, classical simulation and optimization software is used to calculate the elements of the equalizers placed before and after the transistor (Figure 1), taking into account the specifications of the amplifier.

The current dramatic evolution in information technology is bringing major modifications in the way scientists work and communicate. The concept of electronic information handling -and thus of electronic publishing -encompasses the diverse types of information, the different media, as well as the various communication methodologies and technologies. The structure itself of information has become different by the introduction ofhypertextual links. Fluid information is becoming a common concept. While publication is considered here as a public announcement (no implicit assumption being made as to the medium used), it is obvious that electronic publishing will have to diverge from an electronic version of contributions on paper and will become part of a more general diversified publishing policy. The procedures for validating published material and for evaluating scientific activities will have to be adjusted too. Provision of electronic refereed informa¬ tion independently from commercial publishers is now feasible and even maybe highly recommended in view of strict copyright policies tentatively applied by some publishers to the electronic material. In other terms, scientists and scientific institutions have now the possibility to run an efficient information server with validated (refereed) material without the help of a commercial publisher., Heck André. La publication électronique. In: Bulletin de la Classe des sciences, tome 8, n°1-6, 1997. pp. 21-26.

This paper presents an analog design of a biologically inspired neuron model: the conductance-based Hodgkin-Huxley formalism. After a description of the model equations set, the corresponding subcircuits are detailed. ASICs were fabricated in a 2 /spl mu/m BiCMOS technology, and have a block structure allowing the constitution of complex cells or small networks. As an application, numerical and analog computations of the action potentials are compared, and the effects of some model parameters modifications are shown.

Summary: This paper outlines the history of video games, from the Atari generation through Nintendo and Sega to interactive multimedia and hyper-reality. After considering a number of methodological questions, it suggests three different approaches for analysing the habits and behaviour of young players. It then discusses the new generation of adult games and the networks of virtual communities they have spawned on the Internet. The conclusion considers the influence of media games on other sectors of the culture industry., Lafrance Jean-Paul, Libbrecht Liz. Games and players in the electronic age. Tools for analysing the use of video games by adults and children. In: Réseaux. The French journal of communication, volume 4, n°2, 1996. pp. 299-331.

International audience; Besides foundry facilities, Computer-Aided Design (CAD) tools are also required to move microsystems from research prototypes to an industrial market. This paper describes a Computer-Aided-Design Framework for microsystems, based on selected existing software packages adapted and extended for microsystem technology, assembled with libraries where models are available in the form of standard cells described at different levels (symbolic, system/behavioral, layout). In microelectronics, CAD has alreadyattained a highly sophisticated and professional level, where complete fabrication sequences are simulated and the device and systemoperation is completely tested before manufacturing. In comparison, the art of microsystem design and modelling is still in its infancy. However, at least for the numerical simulation of the operation of single microsystem components, such as mechanical resonators, thermo-elements, elastic diaphragms, reliable simulation tools are available. For the different engineering disciplines (like electronics, mechanics, optics, etc) a lot of CAD-tools for the design, simulation and verification of specific devices are available, but there is noCAD-environment within which we could perform a (micro-)system simulation due to the different nature of the devices. In general there are two different approaches to overcome this limitation: the first possibility would be to develop a new framework tailored formicrosystem engineering. The second approach, much more realistic, would be to use the existing CAD-tools which contain the most promising features, and to extend these tools so that they can be used for the simulation and verification of microsystems and of the devices involved. These tools are assembled with libraries in a microsystem design environment allowing a continuous design flow. The approach is driven by the wish to make microsystems accessible to a large community of people, including SMEs andnon-specialized academic institutions.

This study is an extension of the British OCPM (Optically Connected Parallel Machines) collaborative project funded through the LINK Optoelectronic Systems Programme [1]. In a recent paper, we described the particularities of our project with respect to the OCPM project [2]: the wavelength is the usual telecommunication one (λ=1.55µm), the input and output fibers are single-mode (in order to provide a realistic telecommunication demonstrator). The routing is performed by the key-component, a Silicon Backplane Spatial Light Modulator (SBSLM) [3]. This SBSLM is a CMOS 1µm Integrated Circuit (IC) with Ferroelectric Liquid Crystal (FLC) SCE13 (Merck) on the top. The system forms a 8×8 crossbar.

International audience; This paper focuses on the transmission of continuous multimedia streams in packet switched networks, through the use of distributed media scaling techniques. These techniques make it possible for any receiver of a multicast stream to get best possible quality, while avoiding any waste of network resources. Enabling distributed media scaling requires to design network nodes with media scaling capabilities, as well as to design proper control mechanisms that will ensure optimal filter tuning in any node and at any time. A multicast transport protocol allowing network-level media scaling through a special memory management is proposed, and a distributed algorithm which enables optimal tuning of the network node filters is presented.

The purpose of this paper is to present the main developments in the theory of the acoustics of dissipative fluids at rest in bounded spaces (principally cavities of different sizes and shapes), from the early beginnings (in the 1850's) until now, including a brief indication of possible approaches for future developments. Several applications of interest, and current research concerned with miniaturisation, are presented, with emphasis being given to the work done on the acoustic gyrometer and on its potential to be miniaturized, which include the miniaturization of acoustical transducers (on silicon chips)

Dynamic annotation and experimental reading : towards a new gloss? In this paper, we present some reflections about a set of tools enabling a reader to annotate computer-readable texts. A typology of annotative acts is presented. Also are evoked relationships between annotation and other types of text representation, as mark-up, structuring within corpora, or linguistic investigation. It is argued that a computer system of annotation, as a particular type of text manipulation system, gives the user a great power in the management of reading tasks, as memorizing, structuring, reusing, etc., Virbel Jacques. Annotation dynamique et lecture expérimentale : vers une nouvelle glose ?. In: Littérature, n°96, 1994. Informatique et littérature. pp. 91-105.

In this paper, we proposed a approach to the two-microphone speech enhancement problem based on the Blind Separation of Sources for convolutive mixtures. The separation of signals can be achieved by a recursive structure of adaptive Filters FIR. The Filter coefficients must be updated by using Higher Order Statistics in order to insure the output independence. Various adaptive algorithms based on different independence criteria are proposed to estimate the filters. The experimental results have been obtained for different types of signals in various situations of mixtures. For instance, using two microphones, the algorithms are able to separate two speech signals without any knowledge of the signals

This paper describes a new strategy for very large vocabulary speech recognition. The main problem is to reduce the lexical access without pruning the correct candidate. We propose to exploit the branching structure of BDLEX and the description of each word into root and flexional ending. More we use the norion of phonetic classes to decompose the dictionnary into sub-dictionnaries. We develop a two-stage recognirion algorithm: - Each dicrionnary which is considered as a sequence of phonetics classes is modeled by a HMM where the elementaries units are these phonerics classes. - Each word is modeled by a classical HMM where the elementary unit is the pseudodyphone. For a unknown word utterance, a fust recognition gives the best dictionnary to which it belongs, the Viterbi algorithm applied to the network of the best dictionnary words, gives the word with the most likelihood. Experimenu are carried out with telephonic database

In a speech labelling system, traditionnaly the first stage conists in the transcription of the continuous acoustic signal into a series of discrete elementaries units. This stage called Acoustic-Phonetic decoding unrolls three phasis: parametrisarion, segmentation and identification. All the systems do not use the module of segmentation stricktly speaking. For those that use it, they differ from one another in their strategy of segmentation. So we distisguish two different approachs, one is based on an a posteriori segmentation an the other on an a priori one. This paper presents an automatic phoneme recognition system based on a preprocessing segmentation algorithm called the Divergence method. The study of these performances got by Divergence and those obtained by a knowledge based system (SED) where the segmentation is an a posteriori result, has brought us to propose an hybrid system named the SED -Divergence method, using the advantages of the two methods. We asser these systems by integraring them into a labelling process

Developments in digital signal processing allow sound engineers to restore old recordings. The elementary tools used in the mentioned processes are digital editing of sound supported by the advanced visualization of the processed signal, equalizing filtering and adaptive digital filtering used to diminish continuous noise. Moreover, various methods of the elimination of impulse noises were tried. Some of the above methods were practically applied to the constructed computer sound restoration system presented in the paper. Consequently, the multi-task sound restoration method was proposed and practically employed. Application of some types of procedures to the sound restoration of old recordings will be discussed. The reduction of background noise using digital filtering in the critical bands was investigated. Another procedure for old magnetic tape echoes cancellation was implemented and tested. Application of smoothing filters to the elimination of noises will be also discussed

«Tonotechnics» was the term which used to denote the art of driving embossed cylinders used for the manufacture of automated musical instruments. «The art of the organ builder» written in the 18 th century by Dom Bedos de Celles describes the technique. Nowadays the term is used more widely to include the transcription of musical notes not only on cylinders but on other materials such as paper or cardboard, and more particularly on the cards used for mechanical organ music. A machine using «tonotecnics» designed by Robert Hopp has just been presented at the 1992 september music fair in Paris. The purpose of the machine is to produce perforated cards for mechanical organ music using a musical file (format MIDIFILE) recorded on an ordinary musical sequencer. Until now perforating the cards was a long and often hazardous task frequently subject to error. Today, thanks to this machine one can not only reproduce the authentic manner of playing with greater ease and precision but also imagine a new, wider scope for the composition of mechanical organ music. Some parts of the musical score composed by M. Michel PORTAL for the film «l'anniversaire du poisson lune» were only made possible by the design of this machine. Its originality lies in its capacity to reproduce the traditional sounds of the instrument and thanks to sophisticated technology to improve the quality of the cards necessary to produce such music. In the near future we hope to restore to perfect musical order mechanical organ music cards which are too old or badly damaged for use. Currently prized by collectors but impossible to exploit these cards could be scanned by means of a camera or a coupled charge device in order to transcribe their original music onto new cards. Thus the cultural wealth of mechanical organ music could be saved from oblivion

Professionnal deep sea-diving implies that divers inhale synhtetic hyperbaric mixtures to cope with physiological problems observed with air. This modifies the manner speech is produced. Speech under these conditions is alterated and unintelligible. This paper puts forward an approach to make such speech understandable using the respective advantages of tiase-band vocoders and channel vocoders to deal with the difficulties arising from latter. The pitch (periodic glottic wave) supposed unaltered is obtained for synthesis from the hyperbaric signal itself

The intensity measurements technics in architectural acoustics have been developed since the early 1980's. Its utilization has mainly been directed towards the solution of noise transmission or sound isolation problems to analyse the radiation of partition with or without opening and, in some more specialized absorption measurements. As far as the acoustics related to concert halls, the impulse response analysis continues to be the predominant measurement method, since the intensity measurement technics are not very compatible with the time analysis. However, different experiments of data gathering, recorded either in a tightly controlled directional mode or in a omnidirectional mode using a robot or a tridimensional probe, have been reported in concert halls and auditoriums. This paper reviews some of these experiments and presents more recent measurements made in concert halls, showing different technics of reflection analysis as well as a propagation summary at different points of location

The aim of this paper is to show how the use of Relevance Theory can simplify traditional analyses of a range of temporal phenomena. First, it is argued that logical descriptions of the past which treats it as ambiguous can be replaced by a pragmatic analysis which treats the past as univocal. Second, it is shown that the temporal progression characteristic of the so- called narrative past falls out from relevance-theoretic considerations, without the need for logical stipulation. Third, it is argued that a partial explanation for the interpretation of present tense sentences containing dynamic verbs can be derived from the exploitation of the idea of « interpretive use »., Smith Neil. Observations sur la pragmatique des temps. In: Langages, 27ᵉ année, n°112, 1993. Temps, référence et inférence, sous la direction de Jacques Moeschler. pp. 26-38.

M.-T. Vinet The aim of this paper is to discuss the structure of predicate constructions without a copula in French headlines. We show that the categorial selection for the syntactic realization of predication is here partly determined by the semantic properties of a lexical verbal element. We also demonstrate the role of a non-overt Aspectual head in licensing DP predicates which are obligatorily free adjuncts in this register of French. Finally, a brief comparison of predicate constructions in Moroccan Arabic serves to emphasize the universality of certain aspects of these constructions., Vinet Marie-Thérèse. L'aspect et la copule vide dans la grammaire des titres. In: Langue française, n°100, 1993. Temps et aspect dans la langue française, sous la direction de Jacqueline Guéron. pp. 83-101.

L'aide à la décision technique ne consiste pas seulement à informer le décideur, à diagnostiquer l'état des cultures ou prévoir leur évolution, mais aussi à accompagner l'agriculteur dans sa propre démarche d'intégration de ces différents éléments. Un système informatique d'aide à la décision doit alors contenir un modèle des raisonnements mis en oeuvre par l'agriculteur. A partir d'observations par entretiens de quelques processus de décision, on relève quelques caractéristiques structurelles communes à ces raisonnements. On en conclut qu'il est possible de modéliser les processus de décision. De tels modèles sont utilisables dans un but cognitif (pour présenter ce qu'on connait d'un processus de décision), prévisionnel (pour étudier les propriétés de tel ou tel processus de décision), ou décisionnel (comme module d'un système informatique). L'apport potentiel de l'intelligence artificielle en la matière est souligné., Agricultural technical decision support should be used not only to inform the decision-maker, diagnose the state of the crops, or forecast their evolution, but also to accompany the farmer in his own process of integration of these elements. A computer-based decision support system should therefore contain a model of the reasoning carried out by the farmer. The present work attempts to describe and analyse this reasoning. It is based on a series of interviews with 18 farmers (the characteristics of the corresponding cropping systems are in table I, the interview framework in table II). The first section of the paper reports on the 2 types of behavior observed when the farmer is confronted with a technical problem (ie damaged soil structure): he either tries to find out and eliminate the cause of the emergence of the problem or only treats its observed consequences (fig 1). Following this, some common structural characteristics of the reasoning are outlined, leading to the feasibility of modelling decision-making processes. Examples of such models are analysed in 2 particular areas: weeds infestation (fig 2) and the annual crop-plot assignment (fig 3). Some important consequences of the above-mentioned analysis on the designing of decision support systems (DSS) are the necessity for a DSS: to help the farmer in jointly using information processing, diagnosis and solution design facilities; to take into account the temporal and spatial dimensions of the considered decision-making process. In addition, we stress the need for specific research on decision-making processes modeling: 3 classes of models are now considered (fig 4). Decision-making process models may serve 3 purposes: cognitive (to represent what we know about a given decision making process), predictive (to investigate the properties of such and such decision process) and decisive (as part of a DSS). The potential contribution of artificial intelligence in this area is outlined.

In this paper a method of modern control, total linearization by state-feedback, with choice of an input-output behaviour, is applied to a selfcontrolled servomotor. This solution may be a successful alternative to classical strategies. Some examples relative to speed of position control with constraint on the direct axis current show dynamical behaviours which illustrate the possibilities of this method Dans cet article une methode de l'automatique, la linearisation totale par retour d'etat, avec choix d'un comportement entre-sortir, est appliquee a un actionneur electrique non lineaire, un servomoteur synchrome autopilote. Cette solution est une alternative prometteuse aux strategies classiques. Des exemples de dynamiques obtenues sur des commandes en vitesse ou en position, avec contrainte sur le courant d'axe direct, illustrent les possibilites de cette methode

International audience; This paper describes change of basis algorithms for symmetric polynomials. We consider below the three usual following bases : monomial forms, symmetric elementary and Newton polynomials. The originality consists in retaining only one representative of the orbit to make the computations. It is a crucial point if we realize that one orbit can contain commonly hundreds of terms. We implemented these algorithms in FRANZLISP with an interface MACSYMA.

The representation of meaning in natural languages is quite a complex task, which can only be achieved by means of approximative model constructions within the frame of a powerful formalism. This paper provides an introduction to some basic locative concepts , in the formal apparatus of lambda-calculus., Renaud Francis. Analyse sémantique de la localisation en chinois.. In: Cahiers de linguistique - Asie orientale, vol. 14 1, 1985. pp. 5-45.

CARMEN DOBROVIE-SORIN: The subject of the imperative. This paper considers the status of the empty subject noun phrase of the imperative in French and in Rumanian. For Rumanian the analysis draws a parallei between the cases of lexical nouns that occur in the vocative case (to the right of the verb) and the cases with a surface subject. It is shown that in Rumanian the subject of the imperative is of the same type as the subject of other inflected verbs (in Rumanian pronominal subjects are generally deleted). In French thesubject of the imperative may be (is is shown that the empty subject slot is to the right of the verb, as in Rumanian) unlike the nominative subject of other inflected verbs. This possibility is explained by a relation of quantification that binds the subject of the imperative to an «imperative quantifier» which defines the domain of reference of the subject as the set of aIl co-speakers. Our hypothesis, which is is that the subject of the imperative can only occur (as an empty slot) to the right of the verb, accounts for the difference in clitic placing between the imperative and other structures (Tu le tapes / Tape-le)., Dobrovie-Sorin Carmen. Le sujet de l'impératif. In: Histoire Épistémologie Langage, tome 5, fascicule 1, 1983. L'Ellipse grammaticale : Études épistémologiques et historiques, sous la direction de Catherine Fuchs. pp. 129-134.

Cryptography is the art and science of making communications unintelligible to all except the intended receiver. Until recently, the use of cryptographic methods to secure communications has been the sole province of governments, but now, standard cipher systems have been developed in order to protect private data in computer and communication systems from unauthorized disclosure and modification. The study of modern cryptography embraces a number of scientific fields, notably computer science, electronics, logic, number theory, algebra and statistics. Our aim in this paper is to provide a broad introduction to the subject and to present some research topics and some of the most popular methods used today., Roggeman Yves. Méthodes cryptographiques en informatique. In: Bulletin de la Classe des sciences, tome 73, 1987. pp. 490-500.

Summary. — This paper reports the use of an original method in order to compare the boolean and continuous approaches. One makes use of an algorithmic description of their specific and fundamental functioning. A generalized description of the boolean approach is also proposed ; the new idea introduced is the use of a unique real variable (a generalized variable) to describe at the same time a boolean variable and the dynamic state of its on-and off-retarding devices. Thanks to this point of view it is rigorously shown that the boolean approach and the continuous approach with Heaviside functions have similar algorithm, i.e. fundamental functioning. What differs between them is the actual law governing the variation of the variables., Richelle Jean. Analyses booléenne et continue de systèmes comportant des boucles de rétroaction. III. Description algorithmique des approches booléenne et continue. In: Bulletin de la Classe des sciences, tome 69, 1983. pp. 535-565.

The specialized literature may give the impression that the rainfall-runoff process is considered as a quite solved problem. However, when we examine the current models we notice that they are rather cumbersome, difficult to calibrate and not very satisfying by their results. Therefore, one may wonder whether it wouldn't be possible to get the same results with far simpler models. The present paper reports an attempt to conceive such a model.

At a time when the video game industry is booming in Canada and game studies departments begin to emerge in universities, this article assesses the evolution of video game design theories. These can be considered as the combination of two worlds, design theories and video game studies, a union that seems largely under-examined. Using a theoretical model drawn from design theory, namely “the eclipse of the object,” this article reveals similarities between design and video game design theories. It argues that the parallels that can be drawn between these theories constitute the basis for a shared theoretical outlook. Building on this commonality, this paper concludes with some suggestions concerning research, pedagogy, and the video gaming industry that aim at unifying these two domains.