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A review of current sensor technologies and applications within automotive and traffic control systems

PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART D-JOURNAL OF AUTOMOBILE engineering 2000年第D6期214卷 589-614页

作者： Turner, JD Austin, L Transport Res Lab Crowthorne RG45 6AU Berks England Oxford Brookes Univ Oxford OX3 0BP England

This paper reviews the current practice in sensors and sensor applications for automotive and traffic control systems. Sensors to control engine fuelling, ignition and transmission (known as the powertrain) are reviewed, and the likely course of future development is discussed in the light of regulatory and market requirements as well as trends in sensor design and manufacture. Sensor needs for suspension, braking and traction control are also reviewed, and the likely introduction of wheel and tyre sensors to enhance driving safety is discussed. The recent trend towards vehicle-mounted devices to sense the vehicle environment (such as radar, optical, ultrasound, capacitive and image-based systems) is discussed, and the sensor implications of the introduction of safety-critical automotive systems such as adaptive cruise control (ACC) are discussed. Sensors for initiating the deployment of safety systems such as airbags are reviewed, together with transducers for disconnecting fuel pumps and vehicle batteries in the event of a crash. The paper includes a brief discussion of highway-based sensors for measuring vehicle speed and presence, and concludes with a discussion of the likely future developments in the field.

关键词： automotive highway traffic transducers sensors telematics control

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GRADIUM for image intensifier night vision systems for long-range target recognition

GRADIUM for image intensifier night vision systems for long-...

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current developments in Lens design and optical Systems engineering

作者： Pande, R.C. Krishna, K.Siva Rama Instruments Research & Development Establishment Dehradun India

Ever since the gradient index (GRIN) materials came into existence, there have been continuous efforts by various research groups in the world to improve these materials and explore their potential for designing high-performance and compact optical systems. Recently, with the advent of a commercial gradient index glass such as GRADIUM by LightPath Technologies Inc., Arizona, (USA) there has been an increased interest among optical engineers to use these materials for developing realisable GRIN systems. We have previously reported the use of GRADIUM in image intensifier tube based night vision systems such as passive night vision goggles for patrolling and passive night sights for drivers of armored vehicles. These applications generally use systems with unit magnification and large field of view. Derivatives of Double-Gauss configuration are best suited for the front-end objective lens of such systems. In this paper, we discuss the use of GRADIUM in night vision systems for long-range target recognition under low-level of illumination. These applications use image intensifier night vision telescopes having certain desired magnifications. The front-end objectives used for such telescopes should have large focal lengths and high apertures generally in the range of 80 mm to 140 mm for meeting the range specifications for target recognition. Petzval type of configuration is typically used for realizing such large-aperture and low f-number objectives with high contrast at lower frequencies throughout the image field. Use of conventional glass elements in such systems often limits the off-axis performance. We demonstrate, in this paper, the potential of GRADIUM in improving the overall performance of a pair of conventional Petzval objectives used in night vision devices for long range observations.

关键词： optical systems

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Hubble Space Telescope - the new telemetry archiving system

Hubble Space Telescope - the new telemetry archiving system

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Observatory Operations to Optimize Scientific Return ii

作者： Miebach, Manfred P. European Space Agency Baltimore United States

The goals of the project called `Vision 2000 Control Center System (CCS)', are to reduce both development and operating costs significantly for the remaining years of the Hubble Space Telescope's (HST) lifetime. Part of CCS is a Space Telescope engineering Data Store, the design of which is based on current data warehouse technology. The data store will become the engineering data archive and will provide a queryable database for the user to analyze HST telemetry. A CCS system overview is provided and some of the CCS telemetry capabilities, in particular the use of the telemetry archiving system, are illustrated.

关键词： optical telescopes

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Routing and wavelength assignment with power considerations in optical networks

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COMPUTER NETWORKS-THE INTERNATIONAL JOURNAL OF COMPUTER AND TELECOMMUNICATIONS NETWORKING 2000年第5期32卷 539-555页

作者： Ali, R Ramamurthy, B Deogun, JS Univ Nebraska Dept Comp Sci & Engn Lincoln NE 68588 USA

Previous studies have solved many variations of the routing and wavelength assignment (RWA) problem in optical networks under the assumption of perfect conditions regarding the power of a signal. In this paper, we investigate the RWA problem while allowing for degradation of routed signals by optical components. The problem is formulated as a mixed-integer non-linear program. We propose a two-phase approach. In the first phase, we solve the pure RWA problem using fixed routes for every connection. In the second phase, power assignment is accomplished by either using a heuristic or using a genetic algorithm. This paper demonstrates that: (i) connections do interact affecting the power of each other, and (ii) global search meta-heuristics provide better solutions. (C) 2000 Elsevier Science B.V. All rights reserved.

关键词： wavelength division multiplexing (WDM) wavelength-routed networks genetic algorithms power constraints optical amplification

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High power, high reliability CW and QCW operation of single AlGaAs laser diode array design

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Proceedings of SPIE - The International Society for optical engineering 2000年 3945卷 293-300页

作者： Lu, Bo Zucker, Erik Wolak, Ed Dohle, Rainer Zou, Daniel Bicknese, Steve SDL Inc San Jose United States

A single laser diode bar design, based on the AlGaAs material system, has been developed for high power, high reliability operation at a variety of CW and QCW operating conditions. The bar has a cavity length of 750 μm and a fill factor of 40%. Typical CW operation has a threshold current of approximately 10 A and a conversion efficiency of >45% at 40 W. A variety of lifetests have been conducted at both CW and QCW operating conditions from the same bar design. On-going 3000 hr CW operation at 45 C and 40 W shows an extrapolated median lifetime (20% current increase) of 16,500 hrs at 45 C or approximately 50,000 hrs at 25 C (with 0.45 eV activation energy). On-going 3000 hr QCW operation at 60 C/60 W and 35 C/100 W, with a pulse width of 200 μs and a duty factor of 2%, shows a median lifetime of approximately 10 billion shots and approximately 5 billion shots, respectively. In addition to single bar operation, this bar design can be stacked in various 2-D configurations. A 4 bar linear stack operating at 160 W CW and a 6 bar vertical stack operating at 240 W CW have been developed with superior performance. Results for high duty and low duty QCW stacks will also be presented.

关键词： Fiber lasers

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Three dimensional through-wafer fan-out optical interconnects

Three dimensional through-wafer fan-out optical interconnect...

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Optoelectronic Interconnects Vii;Photonics Packaging and Integration ii

作者： LeCompte, Marion Gao, Xiang Bates, Harry Meckel, Jerks Shi, Shouyuan Prather, Dennis W. Univ of Delaware Newark United States

As processor speeds rapidly approach the Gigahertz regime, the disparity between process time and memory access time plays an increasing role in the overall limitation of processor performance. In addition, limitations in interconnect density and bandwidth serve to exacerbate current bottlenecks, particularly as computer architectures continue to reduce in size. To address these issues, we propose a 3D architecture based on through-wafer vertical optical interconnects. To facilitate integration into the current manufacturing infrastructure, our system is monolithically fabricated in the Silicon substrate and preserves scale of integration by using meso-scopic diffractive optical elements (DOEs) for beam fan-out. We believe that this architecture can alleviate the disparity between processor speeds and memory access times while increasing interconnect density by at least an order of magnitude. We are currently working to demonstrate a prototype system that consists of vertical cavity surface emitting lasers (VCSELs), diffractive optical elements, photodetectors, and memory units integrated on a single silicon substrate. To this end, we are currently refining our fabrication and analysis methods for the realization of meso-scopic DOEs. In this paper, we present our progress to date and demonstrate through-Silicon optical data transmission using DOEs that were designed, fabricated, and characterized at the University of Delaware. We present the validation of our theoretical models for the design of such DOEs with experimental data and discuss applications for our proposed architecture including instruction level parallel processors (ILPs) and field programmable gate arrays (FPGAs).

关键词： optical interconnects

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Low driving voltage electrooptic polymer modulators for advanced photonic applications

Low driving voltage electrooptic polymer modulators for adva...

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Conference on Photonic Devices and Algorithms for Computing ii

作者： Bechtel, JH Shi, YQ IPITEK Carlsbad CA 92008 USA

ISBN: (纸本)081943759X

The rapid development of ultra-wide bandwidth fiber optical communications networks has challenged circuit designers to obtain ever-increasing link gain-bandwidth products with new electro-optic modulators. As the link bandwidth increases, high power modulator drivers become very costly and have low efficiency. To overcome the limited gain-bandwidth product, it is important to reduce the required driving voltage or the so-called halfwave voltage of current electro-optic modulators. In this paper, we report results on new polymeric electro-optic modulators with a halfwave voltage of 0.8V and a halfwave voltage-interaction length product of 2.2V-cm. The low driving voltage allows electro-optic modulators to be driven directly by high-speed logic circuits without an amplifier. The driving electronics and the system cost can be significantly reduced when these modulators are implemented. Here, low halfwave voltage modulators are based on recent developments in materials and modulator fabrication technologies. The incorporation of a new second-order nonlinear optical chromophore CLD-1 in a poly(methylmethacrylate) matrix has a demonstrated electrooptic coefficient similar to 60 pm/V at 1318 nm wavelength. Using this material system and an optical push-pull modulator design, sub-1 volt Mach-Zehnder modulators were demonstrated with 3 cm interaction length. The material system, device fabrication, initial characterization, thermal and temporal stability of these modulators will be reported.

关键词： modulator optical communications fiber optics integrated optics electro-optics

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Magneto-optical Recording Materials

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2000年

作者： Richard J. Gambino Takao Suzuki

ISBN: (纸本)9780780310094

"As digital data storage technology undergoes enormous change, electrical engineers, physicists, and materials scientists need to keep pace with the materials requirements for recording media. Expert contributors -- together with world-class authorities Richard J. Gambino and Takao Suzuki -- bring you a practical, comprehensive guide to materials design and selection for magneto-optical storage media. This authoritative book explores multilayered thin films, exchanged coupled layers, materials used in current products, and materials of potential interest not yet available in practical applications. A detailed analysis concerning the physics of magneto-optical recording will help you make informed decisions about materials properties. You will also find an extensive discussion of systems and engineering design features for magneto-optical storage devices. This discussion will help you to understand how materials properties impact system performance. You will gain additional insight into this fast-developing field through in-depth coverage of these featured topics: * Rare earth-transition metal amorphous alloys, multilayers, garnets, intermetallic compounds, and ferrites * Basic principles of domain dynamics and recording physics * Latest developments in exchange coupled layers, direct overwrite, and magnetic superresolution * Minidisc, future high-density systems, and DVD format. MAGNETO-optical RECORDING MATERIALS is essential reading for anyone who needs to keep up-to-date with the latest advances in digital data storage technology."

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Emerging Tools for Single‐Cell Analysis: Advances in optical Measurement Technologies 1

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丛书名： Cytometric cellular analysis

2000年

作者： Gary Durack J. Paul Robinson

ISBN: (数字)9780471224846

ISBN: (纸本)9780471315759

The resurgence of interest in high-resolution evaluation of single-cell properties has led to examining where current technology stands at the beginning of a new millennium. Engineers and scientists have produced significant advances in cytometric technologies in just the past few years. Emerging Tools for Single-Cell Analysis: Advances in optical Measurement Technologies stresses the applications and theories behind some of these advances in cell measurement and cell- sorting technologies. Rapid assessment of the proper function of cells and molecular processes within cells is essential. To that end, new and varying technologies present important diagnostic and prognostic tools relevant to a variety of diseases. Future developments in miniaturization of electronics, micro- and nanomachines, and biomedical engineering are certain to impact cell biology. New analytical technologies are revolutionizing our ability to functionally characterize, isolate, and manipulate single cells. This timely book offers researchers and design engineers much-needed information as they further develop technologies for cell analysis. By comparing and contrasting various approaches, the authors explain how those technologies converge toward similar goals: evaluating the properties of cells and sorting cells on those properties using optically-based measurement systems. Emerging Tools for Single-Cell Analysis offers scientists and engineers a vision of the exciting possibilities that exist as new technologies are applied to single-cell analysis,

关键词： Flow cytometry. Cytophotometry. Flow Cytometry instrumentation. Flow Cytometry methods. Cell separation.

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current research on the ARO-positron emission tomography

Current research on the ARO-positron emission tomography

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Input/Output and Imaging Technologies ii

作者： Jan, Meei-Ling Liang, Hsing-Ching Huang, Shin-Wen Shyu, Chuen-Shing Tang, Jiy-Shan Liu, Hong-Chih Pei, Cheng-Chih Yeh, Ching-Kai Inst of Nuclear Energy Research Taiwan

We are presently constructing `AROPET', a rotating PET scanner for imaging small animals. The design of the system has flexible geometry, using four detectors. Each detector is made of a position-sensitive PMTs (Hamamatsu R3941) coupled with 18×16 small individual BGO scintillator crystals of dimension 2.6×2.6×25 mm3. Animals can be imaged in two modes. One is similar to a gamma camera in which the detectors are stationary, and a 2-D planar projection imaging is obtained. This mode is used for initial characterization of the bio-distribution of tracers. In the other mode the detectors are rotated through 90°, and the diameter can be adjusted between 22 cm to approximately 40 cm. This mode resembles a conventional 3-D PET scan using a partial detector ring. Thirty-one tomographic images can be obtained after rebinning and reconstruction. The field of view is 51.3 mm (transaxial) by 45.6 mm (axial). The spatial resolution of the planar projection mode, and the results of the planar image of a phantom and the dynamical images of the bio-distribution of F18-FDG in a mouse are discussed.

关键词： Positron emission tomography

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