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Displaying 25476 - 25500 of 73878

Approximating the Number of Bases for Almost All Matroids

February 1, 2011
Author(s)
Brian D. Cloteaux
We define a class of matroids A for which a fully polynomial randomized approximation scheme (fpras) exists for counting the number of bases of the matroids. We then show that as the number of elements in a matroid increases, the probability that a matroid

Characterization of Power-to-Phase Conversion in High-Speed P-I-N Photodiodes

February 1, 2011
Author(s)
Jennifer A. Taylor, Shubahshish Datta, Archita Hati, Craig W. Nelson, Franklyn J. Quinlan, Abhay Joshi, Scott A. Diddams
Fluctuations of the optical power incident on a photodiode can be converted into phase fluctuations of the resulting electronic signal due to nonlinear saturation in the semiconductor. This impacts overall timing stability (phase noise) of microwave

Development of Ultrasmall-Angle X-ray Scattering - X-ray Photon Correlation Spectroscopy

February 1, 2011
Author(s)
Fan Zhang, Andrew J. Allen, Lyle E. Levine, Jan Ilavsky, Gabrielle G. Long, Anthony M. Santana
In this paper, we present the development of ultrasmall-angle X-ray scattering - X-ray photon correlation spectroscopy (USAXS-XPCS). This technique takes advantage of Bonse-Hart crystal optics and is capable of probing the slow equilibrium and

Directed 2D-to-3D pattern transfer method for controlled fabrication of topologically complex three- dimensional nanostructures in silicon

February 1, 2011
Author(s)
Konrad Rykaczewski, Owen J. Hildreth, Ching P. Wong, Andrei G. Fedorov, John H. Scott
A process allowing for control over the 3D motion of catalyst nanostructures during Metal-assisted Chemical Etching by their local pinning prior to etching is developed. Topologically complex 3D structures that are partially located within the etched

Electron Beam Induced Growth of TiO2 Nanostructures

February 1, 2011
Author(s)
Renu Sharma
We report the evolution of TiO2 nanostructures when Au nanoparticles, supported on single crystal TiO2 substrates, were heated in ~2 Torr of flowing O2 in an environmental transmission electron microscope. Nanostructures with different morphologies were

Metal-Molecule-Silicon Junctions Produced by Flip Chip Lamination of Dithiols

February 1, 2011
Author(s)
Michael A. Walsh, Curt A. Richter, Christina A. Hacker
The integration of organic molecules with silicon is increasingly being studied for potential uses in hybrid electronic devices. Creating dense and highly ordered organic monolayers on silicon with reliable metal contacts still remains a challenge. A novel

Minimum-Risk Layer 2 Trigger Levels for Proactive Media-Independent Handovers

February 1, 2011
Author(s)
David W. Griffith, Alexandre Delye, Nada T. Golmie
Anticipated handovers that use Link Going Down (LGD) and Link Down (LD) trigger events require the network operator to set the LGD trigger high enough that the handover completes before the LD trigger event. However, setting the LGD trigger too high can

Nanomaterial Toxicity: Emerging Standards and Efforts to Support Standards Development

February 1, 2011
Author(s)
Laurie E. Locascio, Vytautas Reipa, Justin M. Zook, Richard C. Pleus
For the first time in the history of industrialization, nanotechnology offers the unique opportunity to consider material safety ahead of its full implementation. Many scientists around the world have been motivated by this and are working on developing

Study of Nanostructure Inclusion Effects on the Thermoelectric Behavior of Ca3Co4O9 Thin Films Grown by Pulsed Laser Deposition

February 1, 2011
Author(s)
Winnie K. Wong-Ng, Evans L. Thomas, Xueyan Song, Yonggao Y. Yan, Joshua B. Martin, Margaret Ratcliff, Paul N. Barnes
The influence of incorporating nanoparticulate additions into Ca3Co4O9 (CCO) thin films prepared by pulsed laser deposition using composite targets of CCO + BaZrO3 (BZO) on Si, LaAlO3 and Al2O3 substrates is investigated. X-ray data and high-resolution

The program LOPT for least-squares optimization of energy levels

February 1, 2011
Author(s)
Alexander Kramida
The article describes a program that solves the least-squares optimization problem for finding the energy levels of a quantum-mechanical system based on a set of measured energy separations or wavelengths of transitions between those energy levels, as well

A Measurement of the Parity Violating Gamma-ray Asymmetry in the Capture of Polarized Cold Neutrons on Protons

January 31, 2011
Author(s)
Thomas R. Gentile, M T. Gericke, R. Alarcon, S. Balascuta, L. Barron, C S. Blessinger, J D. Bowman, R D. Carlini, W.C. Chen, T E. Chupp, C. Crawford, S. Covrig, M Dabaghyan, N. Formin, S J. Freedman, R C. Gillis, G L. Greene, F W. Hersman, T. Ino, Gordon L. Jones, B Lauss, M Leuschner, W R. Lozowski, R Mahurin, Y Masuda, J Mei, G S. Mitchell, S Muto, H Nann, S A. Page, S I. Penttila, W D. Ramsay, A. Salas-Bacci, S Santra, Katelynn A. Sharma, P.-N. Seo, E I. Sharapov, T B. Smith, William M. Snow, W S. Wilburn, V Yuan
The NPDGamma collaboration reports results from the first phase of a measurement of the parity violating up-down asymmetry A_gamma with respect to the neutron spin direction of gamma-rays emitted in the reaction n + p -> d + gamma using the capture of

An Upper Bound on Parity Violating Neutron Spin Rotation in He-4

January 31, 2011
Author(s)
Jeffrey S. Nico, William M. Snow, Christopher D. Bass, Tiffany D. Bass, B. E. Crawford, K. F. Gan, B R. Heckel, D Lou, D M. Markoff, A M. Micherdzinska, Hans P. Mumm, A. K. Opper, M Sarsour, E I. Sharapov, H E. Swanson, S. C. Walbridge, V Zhumabekova
We report an upper bound on parity violating neutron spin rotation in He-4. This experiment is the most sensitive search for neutron weak optical activity yet performed. Our result for the neutron spin rotation angle per unit length in He-4 is dphi/dz = (

Comprehensive Standard Test Suites for the Performance Evaluation of Mobile Robots

January 31, 2011
Author(s)
Adam S. Jacoff, Hui-Min Huang, Elena R. Messina, Ann M. Virts, Anthony J. Downs
Robots must possess certain sets of capabilities to suit critical operations such as emergency responses. In the mobility function, ground robots must be able to handle many types of obstacles and terrain complexities, including traversing and negotiating

Evaluation of Maps using Fixed Shapes: The Fiducial Map Metric

January 31, 2011
Author(s)
Soren Schwertfeger, Adam S. Jacoff, Christopher Scrapper, Johannes Pellenz, Alexander Kleiner
Mapping is an important task for mobile robots. Assessing the quality of those maps is an open topic. A new approach on map evaluation is presented here. It makes use of artificial objects placed in the environment named "Fiducials". Using the known ground

In-situ Polarized He3-Based Neutron Polarization Analyzer for SNS Magnetism Reflectometer

January 31, 2011
Author(s)
W-T Lee, X Tong, J. Pierce, M. Fleenor, A. Ismaili, JL Robertson, Wangchun Chen, Thomas R. Gentile, A. Hailemariam, R J. Goyette, A. Parizzi, V Lauter, F. Klose, H. Kaiser, C. Lavelle, DV Baxter, G L. Jones, J. Wexler, L. McCollum
We report here the construction and neutron transmission test results of an in-situ polarized 3He-based neutron polarization analyzer system for the Magnetism Reflectometer at the Spallation Neutron Source, Oak Ridge National Laboratory. The analyzer uses

Measures, Uncertainties, and Significance Test in Operational ROC Analysis

January 31, 2011
Author(s)
Jin Chu Wu, Alvin F. Martin, Raghu N. Kacker
In operational ROC (receiver operating characteristic) analysis of fingerprint-image matching algorithms on large datasets, the measures and their accuracies are investigated in the three scenarios: 1) the true accept rate (TAR) of genuine scores at a
Displaying 25476 - 25500 of 73878
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