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Small-Satellite Technology and Applications

作者： Birk, Ronald J. Tompkins, Jim M. Burns, Gregory S. Lockheed Engineering and Sciences Co. Slidell LA USA

ISBN: (纸本)081940604X

The Stennis Space Center acts as the program office for remote sensing activities on behalf of the NASA Office of Commercial Programs. The Commercial Earth Observations Program (CEOP) is a key, cooperative effort with U.S. industry focused on strengthening our nation's economic standing in space-based remote sensing technology. Implementation costs for current remote sensing satellite systems are in the range of $130-300M. Available technology in small launch vehicles and space-qualified subsystem miniaturization could provide a development environment capable of reducing costs, while maintaining performance, Stennis is supplying systems engineering support to determine the technical and economic feasibility of a commercial remote sensing small satellite. Study efforts focus on the systems design of launch vehicle, sensor system, communications, attitude control, power, computational processing, and ground station capabilities. Results reveal that a example small satellite system, with a limited capability remote sensing payload, could be deployed for less than $20M. Technological advances and overall cost reductions in space systems may enable industry to develop new and expanded information service markets.

关键词： Satellites

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Agile manufacturing concept

Agile manufacturing concept

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Coupling Technology to Natl. Need

作者： Goldman, Steven L. Lehigh Univ. (United States)

ISBN: (纸本)0819413879

The initial conceptualization of agile manufacturing was the result of a 1991 study - chaired by Lehigh Professor Roger N. Nagel and California-based entrepreneur Rick Dove, President of Paradigm Shifts, International - of what it would take for U.S. industry to regain global manufacturing competitiveness by the early twenty-first century. This industry-led study, reviewed by senior management at over 100 companies before its release, concluded that incremental improvement of the current system of manufacturing would not be enough to be competitive in today's global marketplace. Computer-based information and production technologies that were becoming available to industry opened up the possibility of an altogether new system of manufacturing, one that would be characterized by a distinctive integration of people and technologies;of management and labor;of customers, producers, suppliers, and society.

关键词： Manufacturing Product engineering Control systems design for manufacturability Information fusion Intellectual property Computing systems Information security Information technology Reliability

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Using optical diagnostics for near field blast testing 8th

Using optical diagnostics for near field blast testing

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8th International Conference on Structural engineering, Mechanics and Computation (SEMC)

作者： Langdon, G. S. Curry, R. J. Rigby, S. E. Pickering, E. G. Clarke, S. D. Tyas, A. Gabriel, S. Yuen, S. Chung Kim von Klemperer, C. J. Univ Sheffield Dept Civil & Struct Engn Sheffield S Yorkshire England Univ Cape Town BISRU Dept Mech Engn Rondebosch South Africa Univ Cape Town Dept Mech Engn Rondebosch South Africa

ISBN: (纸本)9781003348443

The ability to measure the structural and material response to air-blast loading is vital to developing a proper understanding of near-field blast loading and response. Computational modelling has advanced significantly but, until recently, experimental techniques lagged behind. This paper discusses recent advances in these experimental techniques. The first part describes a bilateral test programme between the UK and South Africa. The high-speed imaging and digital image correlation system at Cape Town gives repeatable and accurate impulse distributions across a central strip of a panel, useful for model validation. Flexural wave behaviour was observed from the transient velocity and displacement profiles, giving good insights into the mechanics of plate response from blast loads. The second part demonstrates the value of high-speed stereo-imaging for measuring the transient response of blast loaded fibre reinforced polymer panels and sandwich structures. The peak displacements. elastic rebounds and transient oscillations provide valuable insights into the damage propagation within these types of structures. The final part of the paper describes some of the continued developments since the success of those early trials, resulting in a new optical diagnostics for blast capability at the University of Sheffield. The imaging system operates at higher frame rates and can cover a wider region of interest on the structure. Ultra-high speed imaging is also shown to be a useful tool for visualising detonations fronts in explosive charges and the expanding fireball.

关键词： Fiber reinforced plastics

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design CONSIDERATIONS FOR HIGH-TC SUPERCONDUCTOR MICROSTRIP LINES BASED ON current DISTRIBUTIONS

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MICROWAVE AND optical TECHNOLOGY LETTERS 1991年第8期4卷 302-304页

作者： ELGHAZALY, SM ITOH, T HAMMOND, RB Center for Solid State Electronics Research Arizona State University Tempe Arizona 85287 Department of Electrical Engineering University of California Los Angeles California 90024 Superconductor Technologies Inc. Santa Barbara California 93111

The current distributions on microstrip lines with finite conductor thickness and finite conductivity are investigated in the TM mode. It is found that the lower surface of the conducting strip carries significantly more current than the upper surface. The percentage of the current carried by the lower surface increases with increasing dielectric constant of the substrate. Detailed information on current distributions is useful in design of high-T(c) superconductor lines.

关键词： MICROSTRIP LINES FIELD THEORY CAD SUPERCONDUCTOR LINES

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A design of real time image capturing and processing system using Texas instrument's processor

A design of real time image capturing and processing system ...

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Multimedia Systems and Applications X

作者： Wee, Toon-Joo Chaisorn, Lekha Rahardja, Susanto Gan, Woon-Seng Institute for Infocomm Research Singapore 119613 Singapore School of EEE Nanyang Technology University Singapore 639798 Singapore

ISBN: (纸本)9780819469373

In this work, we developed and implemented an image capturing and processing system that equipped with capability of capturing images from an input video in real time. The input video can be a video from a PC, video camcorder or DVD player. We developed two modes of operation in the system. In the first mode, an input image from the PC is processed on the processing board (development platform with a digital signal processor) and is displayed on the PC. In the second mode, current captured image from the video camcorder (or from DVD player) is processed on the board but is displayed on the LCD monitor. The major difference between our system and other existing conventional systems is that image-processing functions are performed on the board instead of the PC (so that the functions can be used for further developments on the board). The user can control the operations of the board through the Graphic User Interface (GUI) provided on the PC. In order to have a smooth image data transfer between the PC and the board, we employed Real Time Data Transfer (RTDX™) technology to create a link between them. For image processing functions, we developed three main groups of function: (1) Point Processing;(2) Filtering and;(3) 'Others'. Point Processing includes rotation, negation and mirroring. Filter category provides median, adaptive, smooth and sharpen filtering in the time domain. In 'Others' category, auto-contrast adjustment, edge detection, segmentation and sepia color are provided, these functions either add effect on the image or enhance the image. We have developed and implemented our system using C/C# programming language on TMS320DM642 (or DM642) board from Texas Instruments (TI). The system was showcased in College of engineering (CoE) exhibition 2006 at Nanyang Technological University (NTU) and have more than 40 users tried our system. It is demonstrated that our system is adequate for real time image capturing. Our system can be used or applied for application

关键词： Real time systems

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Recent developments in composite-based optics

Recent developments in composite-based optics

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Proceedings of the 1998 Conference on Space Telescopes and Instruments V. Part 1 (of 2)

作者： Kasl, Eldon P. Mehle, Greg V. Dyer, Jack E. Clark, Harold R. Connell, Steven J. Sheikh, David A. Composite Optics Inc San Diego United States

The objective of this paper is to report the recent developments in lightweight mirror technology that have occurred at Composite Optics, Incorporated (COI). The developments occurred as a result of the activities being conducted in support of the Next Generation Space Telescope (NGST), Microwave Limb Sounder (MLS), and Small Business Innovative Research (SBIR) Programs. Our sponsors on these programs are the Marshall and Goddard Space Flight Centers and the Jet Propulsion Laboratory. The requirements, design approach, actual performance, and the technology status for each program are summarized in the following sections. The emergence of composite designs provides exciting potential for nontraditional, accurate, lightweight, stable, stiff, and high strength composite mirrors. This evolving technology promises significant improvement in reducing weight, cost and cycle time for future infrared, visible, and x-ray systems. Customers currently embracing composite mirror technology for radiometric use are already reaping substantial system performance benefits. Other customers interested in LIDAR, IR, visible, and grazing incidence x-ray applications are eagerly awaiting successful completion of current technology development and demonstration efforts.

关键词： Mirrors

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In situ ellipsometric monitoring of complex multilayer designs

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中国光学快报（英文版） 2010年第S1期8卷 44页

作者： Svetlana Dligatch Commonwealth Scientific and Industrial Research Organisation Materials Science and Engineering PO Box 218 Lindf ield NSW 2070 Australia

current developments in optical multilayer design and computation make it possible to calculate filters that satisfy the most demanding optical specifications. Some of the designs are highly sensitive to manufacturing errors and require accurate monitoring and control during thin film deposition. Ellipsometric monitoring enables the accurate deposition of any thickness, including very thin layers, and in situ measurement of both refractive index and thickness of the layers during deposition, which facilitate the subsequent real-time design reoptimisation. In this letter, a number of complex multilayer designs with the aid of ellipsometric monitoring are presented, including a laser notch plus band-blocker filter, dichroic filter, beamsplitter, and a wide-range broadband multiplayer antireflection coating.

关键词： 240.2130 光学监测椭圆偏光法 310.1860 120.2130 光学薄膜多层滤光片

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optical wireless communication for underwater Wireless Sensor Networks: Hardware modules and circuits design and implementation

Optical wireless communication for underwater Wireless Senso...

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OCEANS

作者： Davide Anguita Davide Brizzolara Giancarlo Parodi DIBE-Department of Biophysical and Electronic Engineering University of Genoa Genoa Italy

Underwater wireless optical communication has been used for establish a link between mobile vehicles and/or fixed nodes because light, especially in the blue/green region, allows to achieve higher data-rate than acoustical or electromagnetic waves for moderate distances. The here proposed work has the aim to pave the way for diffuse optical communication allowing to support optical communication in an Underwater Wireless Sensor Network of dense-deployed fixed nodes for specific application, such as monitoring and surveillance, for shallow, coastal and inland water in the case of moderate/limited area. In particular our research explores the possibility of targeting the interface with current available terrestrial technologies. The use of light impulse for communication is motivated by the possibility of targeting high data-rate, low-cost and small dimension components. This paper describes an overall vision of the system: a HDL implementation of flexible modules for the management of optical communication (based on IEEE 802.15.4 and IEEE 802.11 standard) which target the interface with current terrestrial technology for Wireless Sensor Networks; the design and implementation of circuits for underwater optical point-to-point and planar communication. The preliminary results and design consideration are reported considering also future possible developments.

关键词： Wireless sensor networks optical fiber communication Hardware High speed optical techniques optical sensors optical scattering optical attenuators

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Advances in selective laser sintering of polymers

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International Journal of Extreme Manufacturing 2022年第4期4卷 20-56页

作者： Wei Han Lingbao Kong Min Xu Shanghai Engineering Research Center of Ultra-Precision Optical Manufacturing Department of Optical Science and EngineeringFudan UniversityShanghai 200433People’s Republic of China

Polymers are widely used materials in aerospace,automotive,construction,medical devices and *** are being promoted rapidly due to their ease of manufacturing and improved material *** on polymer processing technology should be paid more attention to due to the increasing demand for polymer *** laser sintering(SLS)uses a laser to sinter powdered materials(typical polyamide),and it is one of the critical additive manufacturing(AM)techniques of *** irradiates the laser beam on the defined areas by a computer-aided design three-dimensional(3D)model to bind the material together to create a designed 3D solid *** has many advantages,such as no support structures and excellent mechanical properties resembling injection moulded parts compared with other AM ***,the ability of SLS to process polymers is still affected by some defects,such as the porous structure and limited available types of SLS ***,this article reviews the current state-of-the-art SLS of polymers,including the fundamental principles in this technique,the SLS developments of typical polymers,and the essential process parameters in ***,the applications of SLS are focused,and the conclusions and perspectives are discussed.

关键词： selective laser sintering additive manufacturing laser powder bed fusion 3D printing polymer

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design criteria for helicopter night pilotage sensors

Design criteria for helicopter night pilotage sensors

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Passive Sensors 1991

作者： Vollmerhausen, Richard H. Nash, Carolyn J. US Army CECOM Center for Night Vision and Electro-Optics Fort BelvoirVA United States

The Army requirement to fly helicopters at low level at night led to the development and fielding of night vision pilotage sensors. These sensors have included image intensifiers (I2) operating in the near infrared as well as 8 to 12 micron thermal imagers. The design of current pilotage sensors was driven by available technology. There were no clear data for optimum pilotage sensor design, to enable the designer to trade off sensor field of view (FOV) and resolution or to predict the performance increase which could be obtained by increasing sensitivity. The current Center for Night Vision and Electro-Optics (CCNVEO) effort is an attempt to establish design criteria for night pilotage sensors. It includes flight experiments to find sensor characteristics which optimize flight tasks as well as assessments of the performance of fielded systems. We conclude that terrain flight can be accomplished with reasonable pilot workload using a sensor with 40 degree FOV and 0.6 cycles per mi 11iradian (cy/mrad) resolution. Larger FOV or better resolution will lesson workload and improve confidence;however, the ability to resolve scene detail of 0.6 cy/mrad is essential and should not be traded for increased FOV. Further, a pilotage system which provides both thermal and I2 imagery will significantly enhance system capability to support a variety of flight tasks under a wide range of environments. We also conclude that solid state cameras with detector dwell time equal to the standard video field rate are not suitable for use in pilotage systems. The long dwell time leads to image blur due to the head and scene motion associated with many pilotage tasks. © (1992) 2017 SPIE.

关键词： Image enhancement

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