524 research outputs found
F. Brunot (1860-1937) : la fabrication d'une mémoire de la langue
No full textJean-Claude Chevalier : F. Brunot (1860-1938) : the Fabrication of a Memory of the French Language
This article studies how the French linguist F. Brunot — author of the huge and famed History of the French language — was educated and how his career developed. It shows the way his conception of the history of the French language as memory was strongly determined not only by the French academic tradition, but also above all by the future Brunot envisioned for French society.Chevalier Jean-Claude. F. Brunot (1860-1937) : la fabrication d'une mémoire de la langue. In: Langages, 28ᵉ année, n°114, 1994. Mémoire, histoire, langage, sous la direction de Jean-Jacques Courtine. pp. 54-68
Iterative adaptive approach for unambiguous wideband radar target detection
No full textAccepted author manuscriptMicrowave Sensing, Signals & System
Fast implementation of iterative adaptive approach for wideband unambiguous radar detection
No full textAccepted author manuscriptMicrowave Sensing, Signals & System
Waveform Generation for a MIMO Radar
No full textMultiple-input multiple-output (MIMO) radars achieve improved performance by the simultaneous transmission and reception of waveforms from different locations. Orthogonality of the transmitted waveforms is a requirement for allowing waveform separation at the receiver. In addition, signals with a large BT- product (e.g. coded signals) could be transmitted to achieve high Signal to Noise Ratio (SNR) due to pulse compression. This helps to radiate a larger amount of average power as a result of which range resolution (larger bandwidth) and detection capability improves. These techniques are indeed combined in Space – Time coded active antenna systems, where multiple codes are simultaneously transmitted through the different elements or sub-arrays of an active antenna. My thesis, "Waveform generation for a MIMO Radar" involves the design and implementation of the Arbitrary Waveform Generation (AWG) Block for a multi-channel transmitter of such a MIMO radar test bed. The 8-channel AWG block is developed on an FPGA platform. Besides the AWG, there are the RF and antenna blocks in the multi-channel transmitter. The synchronization of the multiple transmitters is the essential pre-requisite to develop the system. Similarly the individual channels of the system need to be characterized by measuring the errors within the system. The test-bed will be used as a platform for generating and testing different waveforms (binary codes, multi-phase codes, complementary waveforms, etc.) that can provide the radar with required resolutions in range, space, velocity. This could in turn be used to analyze these signals using their ambiguity function in case of space-time adaptive processing. Finally, the influence of the errors on the ambiguity functions for colored waveform transmission could be studied.TelecommunicationsTelecommunicationsElectrical Engineering, Mathematics and Computer Scienc
The role of power exchanges for the creation of a single European electricity market. Market design and market regulation
No full textThe electricity sector worldwide is undergoing a fundamental transformation of its institutional structure as a consequence of the complex interactions of political, economic and technological forces. The way the industry is organized is changing from vertically integrated monopolies to unbundled structures that favor market mechanisms. This process in Europe, known as the liberalization process, has had a wide impact on the European electricity industry. The focus of this dissertation is an analysis of the role of electricity power exchanges in the recently liberalized electricity markets of Europe. In the context of creating 'a' competitive electricity market at a European level, the key questions considered are the functioning of these power exchanges with respect to electricity characteristics, market design and regulatory framework. In Europe, very little attention has been paid to the role of these new marketplaces and to the issue of market design in general. Hence the main purpose of this work was to analyze how these marketplaces facilitate the trading of electricity and the role they can play in the construction of a pan-European competitive electricity market. An analysis of power exchange requires taking into account the 'double-duality' of such institutions. One, power exchanges are both a market and an institution. As a market they facilitate the trading of electricity and determine an equilibrium price. As an institution power exchanges have their own objectives and constraints, and play a role in the market design of the overall electricity market. Two, the relationship between electricity power exchanges and liberalization is neither linear nor one way: liberalization encourages the birth of such marketplaces yet marketplaces are more than the results of such process, they are also a driving force of the liberalization process.Technology, Policy and Managemen
Vitalistic information systems in the South African public health system : a transactional analysis perspective
No full textIncludes bibliographical references
Human Target Tracking in Multistatic Ultra-Wideband Radar
No full textMultistatic ultra-wideband radar is acknowledged to be useful for human tracking in indoor surveillance. In this thesis, a global signal processing chain for detection and localization of moving human targets using a multistatic ultra-wideband radar system is proposed. The design options for the system are presented, and the required signal processing steps are summarized. They include critical steps of tracking, target feature extraction,and target association. A decentralized tracking approach is designed for indoor surveillance. The 1D bistatic tracking rejects clutter and multipath significantly. The 2D tracker employs the global nearest neighbor based Kalman filter to track targets in Cartesian coordinates. The algorithm performance is compared with that of the conventional centralized approach on both simulated and experimental data, and shown to improve clutter and multipath rejection. For feature extraction, the advantages of using range-Doppler imaging are analyzed. The hypothesis-testing based and the Keystone transform based range migration compensation approaches are extended to eliminate the Doppler widening effect in range-Doppler processing of ultra-wideband radar. The proposed compensation approaches are applied to both simulated and experimental data. Special attention is then devoted to the critical issue of target association. Two slow-time features, video time density function and self-similarity matrix, are proposed to characterize target responses in different receiving channels. They indicate the slow-time evolution characteristic of the moving human targets, while staying invariant to radar observation angles. Auction algorithm based global nearest neighbor approach is proposed to tackle the measurement-to-measurement association issue. The decentralized tracking approach is experimentally verified on measured data for indoor detection and location of multiple human targets. Finally, as a by-product of human target feature analysis, range-Doppler surface is proposed to demonstrate the overall target information in range-Doppler video sequence. The conclusion emphasizes the main achievements and highlights the novelties. The recommendation for future work is presented finally to point out potential research topics related to this thesis.Micro-electronicsElectrical Engineering, Mathematics and Computer Scienc
Performance Prediction of Wideband Unambiguous Target Detection in Diffuse Ground Clutter
No full textIn this paper the influence of clutter power spectrum on unambiguous radar target detection with single low pulse repetition frequency wideband waveform is analyzed. Impact of both stationary and diffuse clutter components for different signal bandwidths and coherent processing intervals (CPI) is studied. Exponential model of the ground clutter power spectrum for the diffuse component is used. For the first time, radar detection performance for wideband signals at ambiguous to clutter velocities is predicted as function of bandwidth and CPI.Accepted author manuscriptMicrowave Sensing, Signals & System
De Falstfaff à F for Fake, de Shakespeare à Welles: les puissances du faux et la mort de l’auteur en question
No full textOrson Welles has always been associated with Shakespeare, from early stage when acting to his cinematic adaptations. Falstaff is seen as his double. With his latest film, F for Fake (1975), the Shakespearian dialogue is not so obvious. The aim of this article is to analyse this dialogue within the dialectic between truth and fake, the original and the copy. Can we read in F for Fake an homage to Falstaff, to forgers and illusionists and finally a mirror for Welles? From F for Fake to F for Falstaff, this essay film is questioning the death of the author and the power of the false. It is an artistic will to play with the differentiation between men and myths, truths and lies.<br/
De Falstfaff à F for Fake, de Shakespeare à Welles: les puissances du faux et la mort de l’auteur en question
No full textOrson Welles has always been associated with Shakespeare, from early stage when acting to his cinematic adaptations. Falstaff is seen as his double. With his latest film, F for Fake (1975), the Shakespearian dialogue is not so obvious. The aim of this article is to analyse this dialogue within the dialectic between truth and fake, the original and the copy. Can we read in F for Fake an homage to Falstaff, to forgers and illusionists and finally a mirror for Welles? From F for Fake to F for Falstaff, this essay film is questioning the death of the author and the power of the false. It is an artistic will to play with the differentiation between men and myths, truths and lies.<br/
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