40,532 research outputs found
Object oriented studies into artificial space debris
A prototype simulation is being developed under contract to the Royal Aerospace Establishment (RAE), Farnborough, England, to assist in the discrimination of artificial space objects/debris. The methodology undertaken has been to link Object Oriented programming, intelligent knowledge based system (IKBS) techniques and advanced computer technology with numeric analysis to provide a graphical, symbolic simulation. The objective is to provide an additional layer of understanding on top of conventional classification methods. Use is being made of object and rule based knowledge representation, multiple reasoning, truth maintenance and uncertainty. Software tools being used include Knowledge Engineering Environment (KEE) and SymTactics for knowledge representation. Hooks are being developed within the SymTactics framework to incorporate mathematical models describing orbital motion and fragmentation. Penetration and structural analysis can also be incorporated. SymTactics is an Object Oriented discrete event simulation tool built as a domain specific extension to the KEE environment. The tool provides facilities for building, debugging and monitoring dynamic (military) simulations
Autonomous spacecraft maintenance study group
A plan to incorporate autonomous spacecraft maintenance (ASM) capabilities into Air Force spacecraft by 1989 is outlined. It includes the successful operation of the spacecraft without ground operator intervention for extended periods of time. Mechanisms, along with a fault tolerant data processing system (including a nonvolatile backup memory) and an autonomous navigation capability, are needed to replace the routine servicing that is presently performed by the ground system. The state of the art fault handling capabilities of various spacecraft and computers are described, and a set conceptual design requirements needed to achieve ASM is established. Implementations for near term technology development needed for an ASM proof of concept demonstration by 1985, and a research agenda addressing long range academic research for an advanced ASM system for 1990s are established
Resolving an Individual One-Proton Spin Flip to Determine a Proton Spin State
Previous measurements with a single trapped proton or antiproton detected
spin resonance from the increased scatter of frequency measurements caused by
many spin flips. Here a measured correlation confirms that individual spin
transitions and states are detected instead. The high fidelity suggests that it
may be possible to use quantum jump spectroscopy to measure the p and \pbar
magnetic moments much more precisely.Comment: 4 pages, 7 figure
Recommended from our members
Designing sustainable medical devices
Stakeholders in the medical device manufacturing industry are becoming more concerned about the environmental impact of their products and processes. The consumers are also becoming more aware of the negative impact that manufacturers can have on the environment. Government initiatives continue to increase environmental awareness through the development of new policy and legislation, encouraging industry to become more accountable for the environmental impact of their products and operations. The ISO 14001 standard, Environmental Management Systems-Requirements with Guidance for Use, sets guidelines to enable businesses to recognize the environmental effects of their products and processes. Departments can use the tool to set targets to lower the environmental impact and identify areas of high environmental concern when designing, purchasing, and marketing products. Research in these areas will be used to develop the environmental scoring tool to aid in the design of future sustainable medical devices
Search for the Standard Model Higgs Boson in the Diphoton Decay Channel with 4.9 fb^(-1) of pp Collision Data at √s = 7 TeV with ATLAS
A search for the standard model Higgs boson is performed in the diphoton decay channel. The data used correspond to an integrated luminosity of 4.9 fb^(-1) collected with the ATLAS detector at the Large Hadron Collider in proton-proton collisions at a center-of-mass energy of √s = 7 TeV. In the diphoton mass range 110–150 GeV, the largest excess with respect to the background-only hypothesis is observed at 126.5 GeV, with a local significance of 2.8 standard deviations. Taking the look-elsewhere effect into account in the range 110–150 GeV, this significance becomes 1.5 standard deviations. The standard model Higgs boson is excluded at 95% confidence level in the mass ranges of 113–115 GeV and 134.5–136 GeV
Measurement of the W →τν_τ cross section in pp collisions at √s = 7 TeV with the ATLAS experiment
The cross section for the production of W bosons with subsequent decay W→τν_τ is measured with the ATLAS detector at the LHC. The analysis is based on a data sample that was recorded in 2010 at a proton–proton center-of-mass energy of √s = 7TeV and corresponds to an integrated luminosity of 34 pb^(−1). The cross section is measured in a region of high detector acceptance and then extrapolated to the full phase space. The product of the total W production cross section and the W→τν_τ branching ratio is measured to be σ^(tot)
_(W→τντ) = 11.1±0.3 (stat)±1.7 (syst)±0.4 (lumi) nb
- …