Showing papers by "École normale supérieure de Cachan published in 1989"
TL;DR: In this paper, an analytical model of an eddy current sensor designed for noncontact thickness and distance measurement is presented, which allows the external physical parameters (conductivity and permeability of alloys) to be taken into account.
Abstract: An analytical model of an eddy current sensor designed for noncontact thickness and distance measurement is presented. A dipolar model allows the external physical parameters (conductivity and permeability of alloys) to be taken into account. Analysis of an iron sheet coated with a conductive material gives an accurate interpretation of the detected signals, useful for optimization of the sensor design. Experimental and theoretical data are compared for a galvanization line, demonstrating the potential of this system for nondestructive continuous evaluation. >
30 citations
TL;DR: The Theory of Decision under risk and uncertainty has taken a new course in the last ten years as discussed by the authors, and a tentative interpretation of all this research movement is offered in this paper.
22 citations
01 Jan 1989
TL;DR: In this article, the authors consider a stochastic differential equation driven by a Brownian motion with Lipschitz coefficients and prove that the corresponding flow is, almost surely, almost everywhere derivable with respect to the initial data for any time.
Abstract: We consider a stochastic differential equation, driven by a Brownian motion, with Lipschitz coefficients. We prove that the corresponding flow is, almost surely, almost everywhere derivable with respect to the initial data for any time, and the process defined by the Jacobian matrices is a GLn(ℝ)-valued continuous solution of a linear stochastic differential equation. In dimension one, this process is given by an explicit formula.
19 citations
Patent•
24 May 1989TL;DR: In this article, the output characteristics of a direct transfer pseudoresonant DC-DC converter with an oscillating capacitor (C) are linearized by a control cycle with predetermined control cycles each comprising a direct conduction phase.
Abstract: Process for linearising the (voltage, current) output characteristics of a direct transfer pseudoresonant DC-DC converter (1) comprising an oscillating capacitor (C) and subjected to predetermined control cycles each comprising a direct conduction phase. This process comprises a step for complete discharging of the said oscillating capacitor (C), whatever the output current (IS), this step being commenced at the latest at the end of each direct conduction phase, immediately followed by a step for holding the voltage (VC) at the terminals of the said oscillating capacitor (C) at a substantially zero value. Devices apply this process. Utilisation for the power converters of computers and of on-board electronic systems, of very high specific power.
5 citations
01 Oct 1989
TL;DR: In this article, an eddy current sensor was developed and combined with fast, accurate measurement and digital electronic processing for high-rate simultaneous distance and thickness measurements, making it possible to maintain measurement accuracy even with high-temperature coated samples, using a simple soft correction in the digital processing.
Abstract: An eddy current sensor has been developed and combined with fast, accurate measurement and digital electronic processing for high-rate simultaneous distance and thickness measurements. The system makes it possible to maintain measurement accuracy even with high-temperature coated samples, using a simple soft correction in the digital processing. It is demonstrated how a theoretical analysis based on physical modeling of the sensor has been used to improve the design and performance. Results of measurements in a particular application (galvanization) corresponding to very adverse industrial conditions (the temperature of the coated metal sheet is about 300 degrees C) are presented. >
4 citations