1,043 research outputs found
Hardware Based Projection onto The Parity Polytope and Probability Simplex
This paper is concerned with the adaptation to hardware of methods for
Euclidean norm projections onto the parity polytope and probability simplex. We
first refine recent efforts to develop efficient methods of projection onto the
parity polytope. Our resulting algorithm can be configured to have either
average computational complexity or worst case
complexity on a serial processor where
is the dimension of projection space. We show how to adapt our projection
routine to hardware. Our projection method uses a sub-routine that involves
another Euclidean projection; onto the probability simplex. We therefore
explain how to adapt to hardware a well know simplex projection algorithm. The
hardware implementations of both projection algorithms achieve area scalings of
at a delay of
. Finally, we present numerical results in
which we evaluate the fixed-point accuracy and resource scaling of these
algorithms when targeting a modern FPGA
Radiative corrections for (e,e′p) reactions at GeV energies
A general framework for applying radiative corrections to (e,e′p) coincidence reactions at GeV energies is presented, with special emphasis to higher-order bremsstrahlung effects, radiation from the scattered hadron, and the validity of peaking approximations. The sensitivity to the assumptions made in practically applying radiative corrections to (e,e′p) data is extensively discussed. The general framework is tested against experimental data of the 1H(e,e′p) reaction at momentum transfer values larger than 1.0 (GeV/c)^2, where radiative processes become a dominant source of uncertainty. The formulas presented here can easily be modified for any other electron-induced coincidence reaction
Electron-impact excitation of CrII: A theoretical calculation of effective collision strengths for optically allowed transitions
Meteorites on Mars observed with the Mars Exploration Rovers
Reduced weathering rates due to the lack of liquid water and significantly greater typical surface ages should result in a higher density of meteorites on the surface of Mars compared to Earth. Several meteorites were identified among the rocks investigated during Opportunity’s traverse across the sandy Meridiani plains. Heat Shield Rock is a IAB iron meteorite and has been officially recognized as ‘‘Meridiani Planum.’’ Barberton is olivine-rich and contains metallic Fe in the form of kamacite, suggesting a meteoritic origin. It is chemically most consistent with a mesosiderite silicate clast. Santa Catarina is a brecciated rock with a chemical and mineralogical composition similar to Barberton. Barberton, Santa Catarina, and cobbles adjacent to Santa Catarina may be part of a strewn field. Spirit observed two probable iron meteorites from its Winter Haven location in the Columbia Hills in Gusev Crater. Chondrites have not been identified to date, which may be a result of their lower strengths and probability to survive impact at current atmospheric pressures. Impact craters directly associated with Heat Shield Rock, Barberton, or Santa Catarina have not been observed, but such craters could have been erased by eolian-driven erosion.Additional co-authors: DW Ming, RV Morris, PA de Souza Jr, SW Squyres, C Weitz, AS Yen, J Zipfel, T Economo
Furfuryl Alcohol Emulsion Resins as Co-Binders for Urea-Formaldehyde Resin-Bonded Particleboards
An approach to using water-insoluble furfuryl alcohol (FA) resins as a co-binder for particleboard (PB) urea-formaldehyde (UF) resins was evaluated. Sprayable FA/UF mixed resins were made by emulsifying FA resins of varying advancements and mixing with various formaldehyde to urea (F/U) ratio UF resins in various proportions. The binder performance of the mixed FA/UF resins was then evaluated by bonding laboratory PBs using a weakly acidic ordinary UF resin curing catalyst at various hot pressing temperatures. The PBs were also heat-treated and were aged for two years at room temperature. The test results of bond strengths and formaldehyde emission levels of PBs showed promising improvements at about 30% FA resin additions, although the results were preliminary due to the variable performance nature of such binder systems
SEA 32 MULTI-DOMAIN, MANNED-UNMANNED LITTORAL DENIAL SYSTEM
This report details a systems engineering approach to design a manned-unmanned, multi-domain, littoral denial system of systems, projected over the next decade. Mission context scenarios were created to provide diverse system operating environments, enabling a flexible system architecture to address a variety of threats in near-peer competition. With efforts to employ cost-effective and attritable unmanned components, open-source platform reviews were conducted to determine performance parameters, cost, and technical readiness levels, ultimately influencing the eligibility and appropriateness of these platforms for system integration. This evaluation led to a value system design for each candidate platform, providing quantitative analysis for its potential contribution to our system functions as they pertain to each mission scenario. An optimization program under cost constraints was then utilized to yield ideal platform combinations while meeting all functional requirements. Each architecture that resulted from the optimization program was then subjected to a combat model to verify its effectiveness, and then compared to conventional littoral denial constructs. Analysis and comparison of each system architecture yielded relevant insights for the project sponsor at OPNAV N9I (Director of Warfare Integration). Each scenario-dependent system of systems yielded improvements in certain functional evaluations, while also producing degradations in other functional areas.Approved for public release. Distribution is unlimited.Major, Republic of Singapore NavyMajor, Brazilian Air ForceLieutenant, United States NavyLieutenant, United States NavyLieutenant, United States Nav
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