Institution
Jet Propulsion Laboratory
Facility•La Cañada Flintridge, California, United States•
About: Jet Propulsion Laboratory is a facility organization based out in La Cañada Flintridge, California, United States. It is known for research contribution in the topics: Mars Exploration Program & Telescope. The organization has 8801 authors who have published 14333 publications receiving 548163 citations. The organization is also known as: JPL & NASA JPL.
Topics: Mars Exploration Program, Telescope, Galaxy, Coronagraph, Planet
Papers published on a yearly basis
Papers
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TL;DR: In this paper, the saturation level of the magnetorotational instability (MRI) was investigated using three-dimensional MHD simulations, where the shearing box approximation is adopted and the vertical component of gravity is ignored, so that the evolution of the MRI is followed in a small local part of the disk.
Abstract: The saturation level of the magnetorotational instability (MRI) is investigated using three-dimensional MHD simulations. The shearing box approximation is adopted and the vertical component of gravity is ignored, so that the evolution of the MRI is followed in a small local part of the disk. We focus on the dependence of the saturation level of the stress on the gas pressure, which is a key assumption in the standard alpha disk model. From our numerical experiments it is found that there is a weak power-law relation between the saturation level of the Maxwell stress and the gas pressure in the nonlinear regime; the higher the gas pressure, the larger the stress. Although the power-law index depends slightly on the initial field geometry, the relationship between stress and gas pressure is independent of the initial field strength, and is unaffected by Ohmic dissipation if the magnetic Reynolds number is at least 10. The relationship is the same in adiabatic calculations, where pressure increases over time, and nearly-isothermal calculations, where pressure varies little with time. Our numerical results are qualitatively consistent with an idea that the saturation level of the MRI is determined by a balance between the growth of the MRI and the dissipation of the field through reconnection. The quantitative interpretation of the pressure-stress relation, however, may require advances in the theoretical understanding of non-steady magnetic reconnection.
285 citations
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TL;DR: The Global Land Ice Measurements from Space (GLIMS) project as mentioned in this paper is an international consortium established to acquire satellite images of the world's glaciers, analyse them for glacier extent and changes, and assess change data for causes and implications for people and the environment.
283 citations
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TL;DR: The Configuration Description Language (CDL) is developed to capture the recursive composition of configurations in an architecture- and robot-independent fashion and the Societal Agent theory is presented as a basis for constructions of this form.
Abstract: Specifying a reactive behavioral configuration for use by a multiagent team requires both a careful choice of the behavior set and the creation of a temporal chain of behaviors which executes the mission. This difficult task is simplified by applying an object-oriented approach to the design of the mission using a construction called an assemblage and a methodology called temporal sequencing. The assemblage construct allows building high level primitives which provide abstractions for the designer. Assemblages consist of groups of basic behaviors and coordination mechanisms that allow the group to be treated as a new coherent behavior. Upon instantiation, the assemblage is parameterized based on the specific mission requirements. Assemblages can be re-parameterized and used in other states within a mission or archived as high level primitives for use in subsequent projects. Temporal sequencing partitions the mission into discrete operating states with perceptual triggers causing transitions between those states. Several smaller independent configurations (assemblages) can then be created which each implement one state. The Societal Agent theory is presented as a basis for constructions of this form. The Configuration Description Language (CDL) is developed to capture the recursive composition of configurations in an architecture- and robot-independent fashion. The MissionLab system, an implementation based on CDL, supports the graphical construction of configurations using a visual editor. Various multiagent missions are demonstrated in simulation and on our Denning robots using these tools.
282 citations
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University of Maryland Center for Environmental Science1, University of Wyoming2, University of Pittsburgh3, University of Maryland, College Park4, University of Illinois at Urbana–Champaign5, University of Minnesota6, Oak Ridge National Laboratory7, University of Buenos Aires8, Jet Propulsion Laboratory9, National Center for Geographic Information and Analysis10
TL;DR: In this paper, the authors present an overview of the work of the Institute for Ecological Economics at the University of Maryland and its relationship with the National Center for Geographic Information and Analysis (NCSA).
282 citations
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Planetary Science Institute1, Charles University in Prague2, Spanish National Research Council3, Jet Propulsion Laboratory4, Braunschweig University of Technology5, NASA Lunar Science Institute6, University of Massachusetts Amherst7, Max Planck Society8, International Space Science Institute9, European Space Research and Technology Centre10, Polish Academy of Sciences11, INAF12, University of Trento13
TL;DR: In this article, a high-resolution shape model of the nucleus of the comet 67P/Churyumov-Gerasimenko was used to estimate the porosity of the surface of the cometary nucleus.
282 citations
Authors
Showing all 9033 results
Name | H-index | Papers | Citations |
---|---|---|---|
B. P. Crill | 148 | 486 | 111895 |
George Helou | 144 | 662 | 96338 |
H. K. Eriksen | 141 | 474 | 104208 |
Charles R. Lawrence | 141 | 528 | 104948 |
W. C. Jones | 140 | 395 | 97629 |
Gianluca Morgante | 138 | 478 | 98223 |
Jean-Paul Kneib | 138 | 805 | 89287 |
Kevin M. Huffenberger | 138 | 402 | 93452 |
Robert H. Brown | 136 | 1174 | 79247 |
Federico Capasso | 134 | 1189 | 76957 |
Krzysztof M. Gorski | 132 | 380 | 105912 |
Olivier Doré | 130 | 427 | 104737 |
Mark E. Thompson | 128 | 527 | 77399 |
Clive Dickinson | 123 | 501 | 80701 |
Daniel Stern | 121 | 788 | 69283 |