We review our recent research in the field of photochromic polymeric structures for optical data storage and nonlinear optics. We unify some of the sub -Themes of azopolymer structures in the light of photo -induced m...
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A jamming game is considered. A transmitter encodes the data, in a product code (PC), and transmits it in a slow frequency-hopped spread-spectrum (FHSS) system. A hostile jammer attempts to block correct packet recept...
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A jamming game is considered. A transmitter encodes the data, in a product code (PC), and transmits it in a slow frequency-hopped spread-spectrum (FHSS) system. A hostile jammer attempts to block correct packet reception by adjusting the fraction of the total band in which it distributes the jam power, /spl rho/. Two cases are considered. In the first case, the transmitter declares his strategy and the jammer uses this information to select his best jamming fraction. In the second case, the jammer declares his strategy first and the transmitter uses this information to select his best rates. Results are obtained using asymptotic analysis of a product code using singly extended Reed-Solomon (RS) row and column codes whose size grows large. This asymptotic analysis leads to good choices of the row and column rates for the PC in both cases.
A parallel method developed for reconstructing images from holograms obtained with optical scanning holography is presented. A standard portable message-passing library, MPI or message-passing interface, is used to pr...
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A parallel method developed for reconstructing images from holograms obtained with optical scanning holography is presented. A standard portable message-passing library, MPI or message-passing interface, is used to provide the environment of parallel programming. The parallel method is implemented using a network of workstations. The process of reconstructing images with twin-image removal from holograms is performed in parallel with respect to different reconstruction planes of interest. This process contributes to possible faster three-dimensional object identification to be investigated in future research.
It is generally agreed that the primary scientific goal of the first near Sun fly-by mission is to identify the source of momentum responsible for driving the solar wind and to understand the physics of solar coronal ...
It is generally agreed that the primary scientific goal of the first near Sun fly-by mission is to identify the source of momentum responsible for driving the solar wind and to understand the physics of solar coronal heating. In this paper, we present an innovative concept for obtaining a unique set of data with which to better understand the physics of solar wind acceleration and coronal heating. The instrument, called the Solar Event Correlation Analyzer (SECA), operates on the principle that the topology of the open magnetic field lines can be used to causally correlate the evolution of small scale structures (events) in the Sun’s transition region with in situ solar probe measurements. These small-scale events are generally viewed as the mechanisms providing energy and momentum for the solar corona and wind, an assumption that will be conclusively tested with the SECA instrument. This paper describes the SECA concept and its scientific justification.
作者:
Benbouzid, MEHSpornic, SABody, CDr. Mohamed El Hachemi Benbouzid (1968)
SEE received the B.Sc. degree in Electrical Engineering in 1990 from the Electrical Engineering Institute of Batna University Algeria the MSc. degree in Electrical and Computer Engineering in 1991 from the National Polytechnic Instituteof Grenoble France and the Ph.D. degree also in Electrical and Computer Engineering in 1994 from the National Polytechnic Institute of Grenoble. After graduation he joined the University of Picardie-Jules Verne France where he is Associate Professor at the Professional Institute of Amiens. His currentresearch interests include electric machines anddrives computational of electromagnetics and electromechanical actuation as well as technics for energy savings. He is actually leading a research program on the monitoring and the diagnostics of induction machine drives for the French Picardie Region. He is active in the IEEE Power Engineering Society and is the treasurer of the French Chapter of the IEEE Power Electronics Society. (Laboratoire des Systkmes Automatique Universitk de Picardie-Jules Verne 7. Rue du Moulin Neuf. F-80000 Amiens France Phone: + 33 22 827680 Fax: + 33 22 82 76 82 Sorin Aurel Spornic (1969) received the BSc. degree in Electrical Engineering
in 1993 from “Politehnica” University of Bucharest Romania and the M.Sc. degree in Electrical and Computer Engineering. in 1994 from the National Polytechnic Institute of Grenoble France. In 1995 he joint the Electrotechnic Laboratory of Grenoble (L.E.G.) where he is research assistant working towards a PhD. on magnetic materials. (Laboratoire d'Electrotechnique de Grenoble B.P. 46 F-38402 Saint Martin d'Hèkres. France Phone: +3376 82 62 99 Fax: +3376 82 63 00 Christophe Body (1971) received the B.Sc. degree in Electronics
in 1993 and the M.Sc. degree in Electrical and Computer Engineering. in 1994 from the National Polytechnic Institute of Grenoble France. In 1994 he joined the Electrotechnic Laboratory of Grenoble (L.E.G.). He received the Ph
This paper describes a model for the non-linear magnetomechanical coupling in new highly magnetostrictive materials. This model is devoted to the computer-Aided Design of magnetostrictive devices. It is based on an it...
This paper describes a model for the non-linear magnetomechanical coupling in new highly magnetostrictive materials. This model is devoted to the computer-Aided Design of magnetostrictive devices. It is based on an iterative process of successive magnetic and mechanical computations by a the Finite Element Method. Magnetic and mechanical quantities are still coupled by the iterative process. As a matter of fact, the use of experimental data though the Surface Spline Method allows the introduction of the magnetomechanical coupling. The experimental data are collected from a specially designed sample holder devoted to the static characterization of Terfenol-D rods. Comparisons between numerical outputs from the model and the experimental data reveal that the model is quite powerful to describe the magnetomechanical coupling in highly magnetostrictive materials as Terfonal-D. Otherwise, the proposed model has been extended to take into account the magnetostrictive effect in microsystems using highly magnetostrictive thin films. Numerical computations provide in this case coherent results and show that it is able to describe the global behaviour of highly magnetostrictive microsystems.
In an era of fiscal austerity, downsizing and unforgiving pressure upon human and economic capital, it is an Augean task to identify resources for fresh and creative work. The realities of the day and the practical de...
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In an era of fiscal austerity, downsizing and unforgiving pressure upon human and economic capital, it is an Augean task to identify resources for fresh and creative work. The realities of the day and the practical demands of more immediate fleet needs can often dictate higher priorities. Yet, the Navy must avoid eating its seed corn. Exercising both technical insight and management foresight, the fleet, the R&D community, the Office of the Chief of Naval Operations (OpNav) and the product engineering expertise of the Naval Surface Warfare Center (NSWC) are joined and underway with integrated efforts to marry new, fully demonstrated technologies and operational urgencies. Defense funding today cannot sponsor all work that can be mission-justified over the long term because budgets are insufficient to support product maturation within the classical development cycle. However, by rigorous technical filtering and astute engineering of both marketplace capabilities and currently available components, it is possible in a few select cases to compress and, in effect, integrate advanced development (6.3), engineering development (6.4), weapon procurement (WPN), ship construction (SCN), operation and maintenance (O&M,N) budgetary categories when fleet criticalities and technology opportunities can happily meet. In short, 6.3 funds can be applied directly to ''ripe gateways'' so modern technology is inserted into existing troubled or aging systems, sidestepping the lengthy, traditional development cycle and accelerating practical payoffs to recurrent fleet problems. To produce such constructive results has required a remarkable convergence of sponsor prescience and engineering workforce excellence. The paper describes, extensively, the philosophy of approach, transition strategy, polling of fleet needs, technology assessment, and management team requirements. The process for culling and selecting specific candidate tasks for SHARP sponsorship (matching operational need with t
Using the finite-difference time-domain method, three-dimensional scattering patterns are computed for cells containing multiple organelles. The scattering cross section and average cosine of the scattering angle are ...
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Using the finite-difference time-domain method, three-dimensional scattering patterns are computed for cells containing multiple organelles. The scattering cross section and average cosine of the scattering angle are computed for cells as a function of volume fraction of melanin granules and mitochondria, Results show that small organelles play a significant role in light scattering from cells, and the volume fraction of organelles affects both the total amount of scattered light and the angular distribution of scattered light.
The relationship between optical properties and image contrast in confocal imaging is investigated. A Monte Carlo simulation has been developed to analyze the effects of changes in scattering, index of refraction, and...
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The relationship between optical properties and image contrast in confocal imaging is investigated. A Monte Carlo simulation has been developed to analyze the effects of changes in scattering, index of refraction, and absorption in a three-layer medium. Contrast was calculated from the computed signal-to-background ratios for changes in tissue optical properties. Results show that the largest source of contrast is changes in refractive index. (C) 1996 Optical Society of America
A more complete than usual use of the argument of the identity of photons is suggested for the teaching of radiation processes at the elementary level. The argument uses the concept of 'observability', known f...
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A more complete than usual use of the argument of the identity of photons is suggested for the teaching of radiation processes at the elementary level. The argument uses the concept of 'observability', known from system theory for estimating in the quantum-mechanical and statistical contexts, of the probability of occurrence of a casual process. The introductory discussion in Section 2 explains the reasonability of learning optoelectronics in the device-applicative, physical and system-theoretic aspects, with some emphasis associated with the research interests and pedagogical views of the author.
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