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Displaying 9626 - 9650 of 73751

Integrating four-dimensional ontology and systems requirements modelling

July 18, 2019
Author(s)
Conrad E. Bock, Charles Galey
Ontology has many applications to engineering but is not easily taken up by engineers. For example, specifying products in space and time together (four dimensions) enables more reliable modelling and analysis, but this work is primarily ontological and

Practical Cryptanalysis of k-ary C*

July 18, 2019
Author(s)
Daniel C. Smith-Tone
Recently, an article by Felke appeared in Cryptography and Communications discussing the security of biquadratic $C^*$ and a further generalization, k-ary $C^*$. The article derives lower bounds for the complexity of an algebraic attack, directly inverting

A Cold-Atom Beam Clock, based on Coherent Population Trapping

July 17, 2019
Author(s)
John D. Elgin, Thomas P. Heavner, John E. Kitching, Elizabeth A. Donley, Jayson Denney, Evan Salim
We present results from a novel atomic clock which employs a beam of cold 87 Rb atoms and spatially separated (Ramsey) coherent population trapping interrogation of the hyperfine clock transition at 6.834 GHz. The cold atomic beam is generated through the

Active protection of a superconducting qubit with an interferometric Josephson isolator

July 17, 2019
Author(s)
Baleegh Abdo, Nicholas T. Bronn, Oblesh Jinka, Salvatore B. Olivadese, Antonio D. Corcoles, Vivekananda P. Adiga, Markus Brink, Russell Lake, Xian Wu, David P. Pappas, Jerry M. Chow
Nonreciprocal microwave devices play critical roles in high-fidelity, quantum-nondemolition (QND) measurement schemes. They impose unidirectional routing of readout signals and protect the quantum systems from unwanted noise originated by the output chain

Quantifying Macroeconomic Resilience Dividends in Cedar Rapids

July 17, 2019
Author(s)
Juan F. Fung, Jennifer F. Helgeson, Cheyney M. O'Fallon, David H. Webb, Harvey Cutler
Cedar Rapids, Iowa offers a unique case study in planning for increased resilience. In 2008, Cedar Rapids experienced severe flooding. Rather than simply rebuilding, the city of Cedar Rapids is investing in a resilient flood control system, as well as in

A Novel Dental Sealant Containing Dimethylaminohexadecyl Methacrylate Suppresses the Cariogenic Pathogenicity of Streptococcus mutans Biofilms

July 16, 2019
Author(s)
Nancy Lin, Maria S. Ibrahim, Ahmed Ibrahim, Abdulrahman Balhaddad, Michael D. Weir, Franklin Tay, Thomas Oates, Hockin H. Xu, Mary A. Melo
Cariogenic oral biofilms are strongly linked to dental caries around dental sealants. Quaternary ammonium monomers copolymerized with dental resin systems have been increasingly explored for modulation of biofilm growth. Here, we investigated the effect of

Density Functional Theory Meta GGA Study of Water Adsorption in MIL-53(Cr)

July 16, 2019
Author(s)
Eric J. Cockayne
We use density functional theory meta-GGA TPSS+D3(BJ)+U+J calculations to investigate the energetics and geometry of water molecules in the flexible metal-organic framework material MIL-53(Cr) as a function of cell volume. The critical concentration of

Experimental Upper Bound and Theoretical Expectations for Parity-Violating Neutron Spin Rotation in He-4

July 16, 2019
Author(s)
Jeffrey S. Nico, Hans P. Mumm, H E. Swanson, C. D. Bass, T. D. Bass, J M. Dawkins, J C. Horton, D Luo, William M. Snow, S. C. Walbridge, B. E. Crawford, K. F. Gan, A M. Micherdzinska, C. R. Huffer, D M. Markoff, Murad Sarsour, E I. Sharapov, V Zhumabekova, Blayne R. Heckel
Neutron spin rotation is expected from quark-quark weak interactions in the Standard Model, which induce weak interactions among nucleons that violate parity. We present the results from an experiment searching for the effect of parity violation via the

An 27 Al+ quantum-logic clock with systematic uncertainty below 10 -18

July 15, 2019
Author(s)
Samuel M. Brewer, Jwo-Sy Chen, Aaron M. Hankin, Ethan Clements, Chin-wen Chou, David J. Wineland, David Hume, David Leibrandt
We describe an optical atomic clock based on quantum-logic spectroscopy of the 1S 0 3P 0 transition in 27Al + with a systematic uncertainty of 9.0 x 10-19 and a frequency stability of 1.2 X 10 -15/(T 1/2). A 25Mg + ion is simultaneously trapped with the

Analysis of Different Computational Techniques for Calculating the Polarizability Tensors of Stem Cells with Realistic Three-Dimensional Morphologies

July 15, 2019
Author(s)
Jack F. Douglas, Beatriz Betancourt, Somen Baidya, Ahmed M. Hassan, Waleed Al-Shaikhli, Edward J. Garboczi
In living systems, it is frequently stated that form follows function by virtue of evolutionary pressures on organism development, but in the study of how functions emerge at the cellular level, function often follows form. We study this chicken versus egg

Confirming a Performance Threshold with a Binary Experimental Response

July 15, 2019
Author(s)
Dennis D. Leber, Leticia S. Pibida, Alexander L. Enders
Often, experimenters wish to confirm that a test artifact meets some predefined, fixed performance criterion or claim. For example: does the newly formulated pharmaceutical reduce the disease rate by 10 %; will the composite overwrapped pressure vessel

Measurements of 25 Mg + and 27 Al + magnetic constants for improved ion clock accuracy

July 15, 2019
Author(s)
Samuel M. Brewer, Jwo-Sy Chen, Aaron M. Hankin, Ethan Clements, Chin-wen Chou, Kyle Beloy, Will McGrew, Xiaogang Zhang, Robert J. Fasano, Daniele Nicolodi, Holly Leopardi, Tara Fortier, Scott Diddams, Andrew Ludlow, David J. Wineland, David Leibrandt, David Hume
We have measured the quadratic Zeeman coefficient for the 3P0 excited electronic state in 27Al+, C2=-71.944(24) MHz/T2 and the hyperfine constant of the 25Mg+ 2S1/2 ground electronic state, Ahfs = -596 254 250.981(45) Hz, with improved uncertainties. Both

Progress Towards a Gas-Flow Standard using Microwave and Acoustic Resonances

July 15, 2019
Author(s)
Jodie Gail Pope, Keith A. Gillis, Michael R. Moldover, Eric Harman, James Mehl
We describe our progress in the development of a novel gas flow standard using the acoustic and microwave resonances of a 1.85 m3, nearly-spherical, steel vessel at pressures up to 7 MPa. For flow calibrations using pressure and acoustic frequency

Constant-Round Group Key Exchange from the Ring-LWE Assumption

July 14, 2019
Author(s)
Daniel C. Apon, Dana Dachman-Soled, Huijing Gong, Jonathan Katz
Group key-exchange protocols allow a set of N parties to agree on a shared, secret key by communicating over a public network. A number of solutions to this problem have been proposed over the years, mostly based on variants of Diffie-Hellman (two-party)

On a generalization of the Rogers generating function

July 14, 2019
Author(s)
Howard Cohl, Roberto Costas-Santos, Tanay Wakhare
We derive a generalized Rogers generating function and corresponding definite integral, for the continuous q-ultraspherical polynomials by applying its connection relation and utilizing orthogonality. Using a recent generalization of the Rogers generating

A Classification Scheme for Wireless Channel Models Across the Development Life Cycle

July 12, 2019
Author(s)
David Michelson, Camillo Gentile, Nada T. Golmie, Jeanne Quimby, Kate Remley, Ken Gracie, Yvo de Jong
Wireless channel models play a critical role at all stages of the product life cycle, from standards development to network deployment. However, the distinctive needs and requirements for the channel models used at each stage of the cycle are rarely
Displaying 9626 - 9650 of 73751
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