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IEEE International Symposium on Electromagnetic Compatibility (EMC)

作者： R.C. Scully B.M. Kent K.A. Brezinski D.R. Kempf R.T. Johnk Avionic Systems Division NASA-Johnson Space Center Houston TX USA Air Force Research Laboratory OH USA Electromagnetic Environmental Effects Division Naval Air Warfare Center MD USA Electromagnetics Division National Institute of Science and Technology Boulder CO USA

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Effect of static and dynamic solar sail deformation on center of pressure and thrust forces

Effect of static and dynamic solar sail deformation on cente...

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AIAA Guidance, Navigation, and Control Conference 2006

作者： Sakamoto, Hiraku Park, K.C. Miyazaki, Yasuyuki Massachusetts Institute of Technology Cambridge MA 02139-4307 United States University of Colorado at Boulder Boulder CO 80309-0429 United States Nihon University Chiba 274-8501 Japan JSPS United States Space Systems Laboratory 77 Massachusetts Avenue Cambridge MA 02139 United States AIAA United States Department of Aerospace Engineering Sciences University of Colorado UCB 429 Boulder CO 80309-0429 United States Department of Aerospace Engineering College of Science and Technology Nihon University 7-24-1 Narashinodai Funabashi Chiba 274-8501 Japan

ISBN: (纸本)1563478196

The billowing action of a sail moves the center-of-pressure (cp) and center-of-mass (cm) locations of solar sailcraft thereby creating a torque. It is important to estimate this torque value in order to design an appropriate attitude control devices and algorithms for sailcraft. In addition, the accurate prediction of the cp/cm locations in orbit is desired for efficient non-propellant attitude-control strategies, which change a cm location and/or a cp location. It has been also discussed that the sail billowing may affect the thrust force magnitude and direction. To this end, the present paper studies the change of the thrust force vectors and the cp/cm locations due to the sail billowing for variable parameters, such as sail optical properties, the sail pre-stress level, the sun pitch angle, and distance from the sun. A geometrically nonlinear finite-element method is used to predict the sail billowed shape and the force/moment vectors on the sail. Moreover, the effect of sail deformation due to vibration is preliminarily investigated. The analysis results in this study suggest that the thrust force magnitude and direction are not significantly affected by the sail billowing;the cp/cm-offset torque will be substantial especially for inner solar system missions;and the effect of the sail vibration on the sail thrust forces and moments will be small. Copyright © 2006 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

关键词： space flight

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Mechanical properties of ZrW2O8 filled polymers

Mechanical properties of ZrW2O8 filled polymers

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47th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference

作者： Kroetch, Chris A. Weyer, Wayne C. Cross, William M. Henderson, Brooks D. Kellar, Jon J. Kjerengtroen, Lidvin Welsh, Jeffry Starkovich, John South Dakota School of Mines and Technology Rapid City SD 57701 United States Air Force Research Laboratory Space Vehicles Directorate Kirtland AFB NM 87117 United States Northrop-Grumman Space Technologies Redondo Beach CA 90278 United States Department of Mechanical Engineering 501 E. St. Joseph St. United States Materials Engineering and Science Program 501 E. St. Joseph St. United States Department of Materials and Metallurgical Engineering 501 E. St. Joseph St. United States Integrated Structural Systems SE Bldg. 472 3550 Aberdeen Ave. United States NGST Structures and Mechanisms Product Center Mail Stop R4-2112 One Space Park

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ISBN: (纸本)1563478080

No abstract available

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The compliance contact model of cylindrical joints with clearances

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Acta Mechanica Sinica 2005年第5期21卷 451-458页

作者： Caishan Liu Ke Zhang Lei Yang Department of Mechanics and Engineering Science State Key Laboratory of Turbulence and Complex SystemsPeking University Beijing 100871 China Chinese Academe of Space Technology Beijing 100086 China

This paper is concerned with the determination of the normal force-displacement （NFD） relation for the contact problem of cylindrical joints with clearance. A simple formulation for this contact problem is developed by modeling the pin as a rigid wedge and the elastic plate as a simple Winkler elastic foundation. The numerical results show that the normal displacement relation based on Hertz theory is only valid for the case of large clearance with a small normal load, and the NFD relation based on Persson theory is only effective in the case of very small clearance. The proposed approximate model in this paper gives better results than Hertz theory and Persson theory in a large range of clearances as seen from the comparison with the results of FEM.

关键词： Cylindrical joint with clearance .Conformalcontact. FEM

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A view of Hurricane Katrina with early 21st century technology

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Eos 2006年第41期87卷 433+440页

作者： Lin, Xin Li, Jui-Lin F. Suarez, Max J. Tompkins, Adrian M. Waliser, Duane E. Rienecker, Michele M. Backmeister, Julio Jiang, Jonathan H. Wu, Huey-Tzu Tassone, Caterina M. Chern, Jiun-Dar Chen, Baode Su, Hui NASA Goddard Space Flight Center (GSFC) Greenbelt MD United States University of Maryland Baltimore County (UMBC) Baltimore MD United States Jet Propulsion Laboratory (JPL) California Institute of Technology (Caltech) Pasadena CA United States SkillStorm Inc. Pasadena CA United States European Center for Medium-Range Weather Forecasts Reading United Kingdom NASA GSFC Science and Systems and Application Inc. Lanham MD United States NASA GSFC Science Applications International Corporation (SAIC) Beltsville MD United States

Observing, modeling, and forecasting systems have been undergoing rapid development in the past two to three decades. For example, Atlantic hurricanes are closely monitored by the U.S. National Oceanic and Atmospheric Administration's (NOAA) National Weather Service through a significantly improved upper-air and ground-based observational network supplemented by aircraft, ship, and ocean buoy data. Given initial conditions and lateral boundary conditions provided by larger-scale model analyses, regional models have been widely utilized to predict hurricane track and ***, satellite observations are playing an increasingly important role in providing global estimations of precipitation, radiative fluxes, clouds, and winds, with unprecedented temporal and spatial coverage. Global atmospheric models and global operational analyses are moving toward providing forecasts and products at resolutions ranging from 0.1° to 0.5° (10–50 kilometers).There is evidence that improved hurricane structure and track forecasts could result in part from such increases in model resolution.

关键词： .Hurricane Katrina Methane

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Driving cycle simulation for heady duty engine emission evaluation and testing

Driving cycle simulation for heady duty engine emission eval...

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Powertrain and Fluid systems Conference and Exhibition

作者： Montazeri-Gh, Morteza Varasteh, Hirbod Naghizadeh, Mojtaba Systems Simulation and Control Laboratory Department of Mechanical Eng Iran University of Science and Technology Narmak Tehran 16844 Iran Division of Mechatronics Department of Signals and Systems Chalmers University SE-412 96 Gothenburg Sweden

Driving cycle simulation of the heavy duty vehicle powertrain systems is presented as a methodological approach for evaluation of the engine operating points used for emission testing. This approach employs a backward facing method based on the quasi-steady approximation using the engine steady state characteristics. The driving cycle used in this study is extracted from the experimental data collected from the city buses in the real traffic conditions of the city of Tehran. The driving cycle is divided into several traffic conditions including congested, urban and extra-urban (highway). Several driving modes have also been considered including idle, cruise, deceleration and acceleration. The driving cycle simulation is then used to obtain the distribution of the engine operation for several driving cycles, traffic conditions and driving modes. Finally, the mapping from the driving cycle SAPM into the engine SLPM is employed to analyze the results. This study reveals that the common used 13-mode heavy duty engine test cycle is not necessarily compatible with the engine operating points for the city bus application, in particular at idle condition. Copyright © 2005 SAE International.

关键词： Engines

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Performance simulation modeling for fast evaluation of pipelined scalar processor by evaluation reuse

Performance simulation modeling for fast evaluation of pipel...

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Design Automation Conference

作者： Ho Young Kim Tag Gon Kim Department of EECS Systems Modeling Simulation Laboratory Korea Advanced Institute of Science and Technology South Korea

ISBN: (纸本)1595930582

This paper proposes a rapid and accurate evaluation scheme for cycle counts of a pipelined processor using evaluation reuse technique. Since exploration of an optimal processor is a time-consuming task due to large design space, fast evaluation methodology for an architecture is crucial. We introduce the performance simulation model which can evaluate the performance without considering the functional correctness. This model has an FSM-like form and can afford to take all hazard types of pipelined architectures into consideration. The proposed approach is based on the property that an application program, especially multimedia application, has many iterative loops in general. This property invokes many iterative operations in the simulation. Evaluation reuse scheme can alleviate redundantly iterative operations of conventional simulators in the loop. A performance simulator for the pipeline architecture has been developed through which greater speedup has been made compared with other approaches in the evaluation of cycle counts.

关键词： Computational modeling Iterative methods Computer architecture Computer simulation Scheduling Pipelines Permission Laboratories Hazards space exploration

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Sub-millimetre wave (terahertz) observations of the Solar System gaseous planets and planetary satellites

Sub-millimetre wave (terahertz) observations of the Solar Sy...

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39th ESLAB Symposium: Trends in space science and Cosmic Vision 2020

作者： Ellison, B. Dunkin, S. Matheson, D. Thomas, B. Miller, S. Aylward, A. Zarnecki, J. Charlton, J. De Maagt, P. Space Science and Technology Dept. Rutherford Appleton Laboratory Chilton Didcot Oxon United Kingdom Atmospheric Physics Laboratory Dept. Physics and Astronomy University College London United Kingdom Planetary and Space Science Research Institute Open University Walton Hall Milton Keynes United Kingdom SULA Systems Old Crown House Wotton-under-Edge Gloucestershire United Kingdom Electromagnetics Division European Space Agency Noordwijk Netherlands

ISBN: (纸本)9290928999

spaceborne sub-millimetre wave (terahertz) observations of the gaseous planets and planetary satellites provide a new scientific opportunity to further enhance our knowledge and understanding of our Solar System. Through a variety of European space Agency led technology development initiatives, specifically aimed at underpinning terrestrial atmospheric remote sounding and astronomy observations (from ground, air- and space-borne observatories), sub-millimetre wave technology has made, and continues to make, considerable improvement in sensitivity and operational resource demands. Because of this, implementation of relevant sub-millimetre wave (terahertz) detection systems capable of providing in-situ planetary observations has become increasingly realistic arid feasible and offer Planetary Scientists a novel opportunity to explore an important spectral range, with high radiometric precision and high spatial resolution, in relation to planetary atmospheres and surface features. This exploration opportunity is consistent with the scope of Cosmic Vision.

关键词： Submillimeter waves

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Fluorescence explorer (FLEX): An optimised payload to map vegetation photosynthesis from space

Fluorescence explorer (FLEX): An optimised payload to map ve...

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AIAA 57th International Astronautical Congress, IAC 2006

作者： Moreno, Jose F. Asner, Gregory P. Bach, Heike Belenguer, Tomas Bell, Andrew Buschmann, Claus Calera, Alfonso Calpe, Javier Campbell, Petya Cecchi, Giovanna Colombo, Roberto Corp, Lawrence A. Court, Andrew Cutter, Mike A. Disney, Mathias Dudelzak, Alexander D'Urso, Guido Fernandes, Richard Flexas, Jaume Gege, Peter Gielen, Birgit Gitelson, Anatoly Gloor, Emanuel U. Gower, Jim Green, Robert O. Hill, Joachim Jacquemoud, Stephane Jia, Li Kneubühler, Mathias Laurila, Tuomas Lewis, Philip Lobb, Dan Magnani, Federico Maier, Stefan W. Marek, Michal V. Martinez, Alfonso Martinez-Cobo, Pablo Mazzinghi, Piero Menenti, Massimo Merton, Ray Middleton, Elizabeth De Miguel, Eduardo Miller, John Mohammed, Gina Milton, Edward J. Morales, Fermin Moya, Ismael Nedbal, Ladislav Knorr, Wolfgang Ottlé, Catherine Olioso, Albert Pace, Stefania Palucci, Antonio Pedros, Roberto Peltoniemi, Jouni Peñuelas, Josep Plaza, Antonio Polcher, Jan Rascher, Uwe Reuter, Rainer Rosema, Andries Roujean, Jean-Louis Saito, Yasunori Saugier, Bernard Schaepman, Michael Serrano, Jesus B. Settle, Jeff J. Sierra, Mercedes Sobrino, Jose Stoll, Marc-Philippe Bob Su, Z. Tobehn, Carsten Tremblay, Nicolas Valcke, Roland Verhoef, Wout Veroustraete, Frank Verstraete, Michel Zarco-Tejada, Pablo Dept. Earth Physics and Thermodynamics Faculty of Physics University of Valencia Dr. Moliner 50 46100 Burjassot Valencia Spain Carnegie Institution of Washington Stanford CA United States VISTA GmbH Munich Germany INTA Madrid Spain EMS Technologies Canada Ltd. Ottawa ON Canada Universität Karlsruhe - Botanik II Karlsruhe Germany University of Castilla-La Mancha Albacete Spain Electronics Dept. Engineering School Valencia Spain NASA Goddard Space Flight Center Greenbelt MD United States Applied Physics Institute CNR Florence Italy Dept. Environmental Sciences Univ. Milano Bicocca Italy USDA ARS Hydrology and Remote Sensing Lab. Beltsville MD United States TNO Science and Industry Netherlands Sira Technology Ltd. Chislehurst Kent United Kingdom NERC CTCD UCL London United Kingdom CSA Montreal Canada Dept. Agricultural Engineering University of Naples Federico II Naples Italy CCRS Ottawa ON Canada UIB-CSIC Universität de les Ules Balears Palma de Mallorca Baleares Spain Remote Sensing Technology Institute DLR Oberpfaffenhofen Germany Department of Biology University of Antwerp Wilrijk Belgium University of Nebraska Lincoln NE United States Univ. Princeton United States Institute of Ocean Sciences Canada NASA Jet Propulsion Laboratory Pasadena CA United States University of Trier Germany University Paris Paris France Alterra Wageningen University Netherlands Remote Sensing Laboratories University of Zurich Switzerland FMI Helsinki Finland DCA University of Bologna Italy Satellite Remote Sensing Services Dep. Land Information Floreat WA Australia Laboratory of Ecological Physiology Brno Czech Republic EADS-CASA Espacio Madrid Spain GRNPS University of Extremadura Spain INOA Florence Italy LSIIT Université Louis Pasteur Strasbourg France Centre for Remote Sensing GIS University of New South Wales Sydney Australia York University Toronto Canada P and M Technologies Canada School of Geography University of Southampton U

ISBN: (纸本)9781605600390

The FLuorescence EXplorer (FLEX) mission proposes to launch a satellite for the global monitoring of steady-state chlorophyll fluorescence in terrestrial vegetation. Fluorescence is a sensitive probe of photosynthetic function in both healthy and physiologically perturbed vegetation, and a powerful non-invasive tool to track the status, resilience, and recovery of photochemical processes and moreover provides important information on overall photosynthetic performance with implications for related carbon sequestration. The early responsiveness of fluorescence to atmospheric, soil and plant water balance, as well as to atmospheric chemistry and human intervention in land usage makes it an obvious biological indicator in improving our understanding of Earth system dynamics. The amenability of fluorescence to remote, even space-basedobservation qualifies it to join the emerging suite of space-based technologies for Earth observation. FLEX would encompass a three-instrument array for measurement of the interrelated features of fluorescence, hyperspectral reflectance, and canopy temperature. FLEX would involve a space and ground-truthing program of 3-years duration and would provide data formats for research and applied science.

关键词： space research

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Illustrative visualization

Illustrative visualization

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VIS 05: IEEE Visualization 2005, Proceedings

作者： Viola, Ivan Gröller, Meister E. Hadwiger, Markus Bühler, Katja Preim, Bernhard Sousa, Mario Costa Ebert, David S. Stredney, Don Kanitsar, Armin Bruckner, Stefan Grimm, Sören Svakhine, Nikolai A. Jang, Yun Gaithert, Kelly Tietjen, Christian Krüger, Arno Peitgen, Heinz-Otto Isenberg, Tobias Hintze, Jana Hertel, Ilka Strauß, Gero Institute of Computer Graphics and Algorithms Vienna University of Technology Austria VRVis Research Center Vienna Austria Department of Simulation and Graphics University of Magdeburg Germany Department of Computer Science University of Calgary Canada School of Electrical and Computer Engineering Purdue University United States Ohio Supercomputer Center United States Institute of Computer Graphics and Algorithms Vienna University of Technology Austria VRVis Research Center Vienna Austria Electrical and Computer Engineering Purdue University United States IEEE Austria Department of Computer Science University of Calgary Canada Department of Computer Science Computer Graphics Research Lab. University of Calgary Canada Purdue University United States Ohio Supercomputer Center United States University of Texas Austin United States Interface Laboratory United States Biomedical Applications United States Department of Simulation and Graphics Otto-von-Guericke-University of Magdeburg Germany Otto-von-Guericke-University of Magdeburg FIN/ISG Germany Institute for Simulation and Graphics Department for Computer Science Otto-von-Guericke-University of Magdeburg Universitaetsplatz 2 39106 Magdeburg Germany Center for Medical Diagnosic Systems and Visualization Universitaetsallee 29 28359 Bremen Germany Department of Simulation and Graphics Otto-von-Guericke University of Magdeburg Germany ENT Department University Hospital of Leipzig Germany

ISBN: (纸本)0780394623

The tutorial presents state-of-the-art visualization techniques inspired by traditional technical and medical illustrations. Such techniques exploit the perception of the human visual system and provide effective visual abstractions to make the visualization clearly understandable. Visual emphasis and abstraction has been used for expressive presentation from prehistoric paintings to nowadays scientific and medical illustrations. Many of the expressive techniques used in art are adopted in computer graphics, and are denoted as illustrative or non-photorealistic rendering. Different stroke techniques, or brush properties express a particular level of abstraction. Feature emphasis or feature suppression is achieved by combining different abstraction levels in illustrative rendering. Challenges in visualization research are very large data visualization as well as multi-dimensional data visualization. To effectively convey the most important visual information there is a significant need for visual abstraction. For less relevant information the dedicated image space is reduced to enhance more prominent features. The discussed techniques in the context of scientific visualization are based on iso-surfaces and volume rendering. Apart from visual abstraction, i.e., illustrative representation, the visibility of prominent features can be achieved by illustrative visualization techniques such as cut-away views or ghosted views. The structures that occlude the most prominent information are suppressed in order to clearly see more interesting parts. A different smart way to provide information on the data is using exploded views or other types of deformation. Furthermore intuitive feature classification via 3D painting and manipulation with the classified data including label placement is presented. Discussed non-photorealistic and illustrative techniques from visualization and graphics are shown from the perspective as tools for illustrators from medicine, botany, archeology

关键词： Visualization

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