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NIST Authors in Bold

Displaying 18301 - 18325 of 73929

Traceability for Microwave Power Measurements: Past, Present, and Future

April 13, 2015
Author(s)
Ronald A. Ginley
The need for traceable microwave power measurements for use in communications, defense, spectral line investigation, molecular particle signature identification, material property characterization and others is well established. Traceability for power

Comparison of Two Continuous GPS Carrier-Phase Time Transfer Techniques

April 12, 2015
Author(s)
Jian Yao, Skakun Ivan, Zhiheng Jiang, Judah Levine
Global Positioning System (GPS) carrier-phase (CP) time transfer, as a widely accepted high-precision time transfer method, frequently shows a data-batch boundary discontinuity of up to 1 ns, because of the inconsistency of the phase ambiguities between

Practical Limitations of NTP Time Transfer

April 12, 2015
Author(s)
Andrew N. Novick, Michael A. Lombardi
The Network Time Protocol (NTP) is commonly utilized to synchronize computer clocks in packet-switched, wide area networks (WANs) such as the public Internet. The delay asymmetry in WANs, often due to inconsistent routing and/or bandwidth saturation, is

Time Signals Converging within Cyber-Physical Systems

April 12, 2015
Author(s)
Marc A. Weiss, Sundeep Chandhoke, Hugh Melvin
Time is central to predicting, measuring and controlling properties of the physical world, and is one of the most important constraints distinguishing Cyber-Physical Systems (CPS) from distributed computing in general. However mixing the cyber and the

Assembling a complex quantum ensemble

April 10, 2015
Author(s)
Ian B. Spielman
Statistical mechanics provides a systematic approach for predicting the behavior of systems when only partial information is present. The key assumption underlying all of statistical mechanics is that every allowed configuration of the system, called a

High-efficiency superconducting nanowire single-photon detectors fabricated from MoSi thin-films

April 10, 2015
Author(s)
Varun B. Verma, Boris Korzh, Felix Bussieres, Robert D. Horansky, Shellee D. Dyer, Adriana E. Lita, Igor Vayshenker, Francesco Marsili, Matthew D. Shaw, Hugo Zbinden, Richard P. Mirin, Sae Woo Nam
We demonstrate high-efficiency superconducting nanowire single-photon detectors (SNSPDs) fabricated from MoSi thin-films. We measure a maximum system detection efficiency (SDE) of 87 ± 0.5 % at 1542 nm at a temperature of 0.7 K, with a jitter of 76 ps

Light shifts in a pulsed cold-atom coherent-population-trapping clock

April 10, 2015
Author(s)
Eric M. Blanshan, Elizabeth A. Donley, John E. Kitching
Field-grade atomic clocks capable of primary standard performance in compact physics packages would be of significant value in a variety of applications. A cold-atom coherent population trapping clock featuring laser-cooled 87Rb atoms and pulsed Ramsey

Research Needs to Advance Concrete Pumping Technology

April 10, 2015
Author(s)
Chiara F. Ferraris, Nicos Martys, Myoungsung Choi, Van Bui, Trey Hamilton, Didier Lootens
With the increasing use of pumping to place concrete, the development and refinement of the industry practice to ensure successful concrete pumping is becoming an important need for the concrete construction industry. To date, research on concrete pumping

Calibration of Millimeter-wave Channel Sounders for Super-resolution Multipath Component Extraction

April 9, 2015
Author(s)
Peter B. Papazian, Jae-Kark Choi, Jelena Senic, Peter J. Jeavons, Camillo Gentile, Nada T. Golmie, Roy Sun, David R. Novotny, Kate Remley
Millimeter-wave communication systems will rely on highly directional antennas to compensate for the greater pathloss expected in their frequency bands of operation. Electronic beamforming, hence, will form a cornerstone for the technology. For the

Direct correlation of charge transfer absorption with molecular donor:acceptor interfacial area via photothermal deflection spectroscopy

April 9, 2015
Author(s)
Lee J. Richter, Dean M. DeLongchamp, Natalie Stingelin, Alberto Salleo, Martin Heeney, Aram Amassian, John deMello, James Bannock, Fiona H. Scholes, Scott Watkins, Zhuping Fei, Koen Vandewal
ABSTRACT: Here, we show that the Charge Transfer (CT) absorption signal in bulk (BHJ) solar cell blends, measured by photothermal deflection spectroscopy (PDS), is directly proportional to the density of molecular donor/acceptor interfaces. Since the

Evaluating automatic face recognition systems with human benchmarks

April 9, 2015
Author(s)
P. Jonathon Phillips, Alice O'Toole
Human face recognition skills are often considered the gold standard against which machines must compete. Over the last two decades, however, international tests of computer-based face recognition algorithms have shown steady improvements in accuracy with

Incorporating D3.js Information Visualization into Immersive Virtual Environments

April 9, 2015
Author(s)
Wesley N. Griffin, Luis D. Catacora, Jeffrey W. Bullard, Judith E. Terrill
We have created an integrated interactive visualization and analysis environment that can be used immersively or on the desktop to study a simulation of microstructure development during hydration or degradation of cement pastes and concrete. Our

Password Entry Errors: Memory or Motor?

April 9, 2015
Author(s)
Kristen Greene, Frank Tamborello
As we increasingly rely upon our computer information systems to store and operate on sensitive information, the methods we use to authenticate user identity also become more important. One of the most important such methods is the password. However
Displaying 18301 - 18325 of 73929
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