2,689 research outputs found
The artificial electron belt, October 1963 to October 1966
Measured decay of Starfish electron radiation belt from October 1963 to October 196
Scalable arrays of RF Paul traps in degenerate Si
We report techniques for the fabrication of multi-zone linear RF Paul traps
that exploit the machinability and electrical conductivity of degenerate
silicon. The approach was tested by trapping and laser cooling 24Mg+ ions in
two trap geometries: a single-zone two-layer trap and a multi-zone
surface-electrode trap. From the measured ion motional heating rate we
determine an electric field spectral density at the ion's position of
approximately 1E-10 (V/m)^2/Hz at a frequency of 1.125 MHz when the ion lies 40
micron above the trap surface. One application of these devices is controlled
manipulation of atomic ion qubits, the basis of one form of quantum information
processing.Comment: 3 pages; 2 figures; v2: fix heating rate typ
Exploring the Referral and Usage of Science Fiction in HCI Literature
Research on science fiction (sci-fi) in scientific publications has indicated
the usage of sci-fi stories, movies or shows to inspire novel Human-Computer
Interaction (HCI) research. Yet no studies have analysed sci-fi in a top-ranked
computer science conference at present. For that reason, we examine the CHI
main track for the presence and nature of sci-fi referrals in relationship to
HCI research. We search for six sci-fi terms in a dataset of 5812 CHI main
proceedings and code the context of 175 sci-fi referrals in 83 papers indexed
in the CHI main track. In our results, we categorize these papers into five
contemporary HCI research themes wherein sci-fi and HCI interconnect: 1)
Theoretical Design Research; 2) New Interactions; 3) Human-Body Modification or
Extension; 4) Human-Robot Interaction and Artificial Intelligence; and 5)
Visions of Computing and HCI. In conclusion, we discuss results and
implications located in the promising arena of sci-fi and HCI research.Comment: v1: 20 pages, 4 figures, 3 tables, HCI International 2018 accepted
submission v2: 20 pages, 4 figures, 3 tables, added link/doi for Springer
proceedin
Corrugated Silicon Platelet Feed Horn Array for CMB Polarimetry at 150 GHz
Next generation cosmic microwave background (CMB) polarization anisotropy
measurements will feature focal plane arrays with more than 600 millimeter-wave
detectors. We make use of high-resolution photolithography and wafer-scale etch
tools to build planar arrays of corrugated platelet feeds in silicon with
highly symmetric beams, low cross-polarization and low side lobes. A compact
Au-plated corrugated Si feed designed for 150 GHz operation exhibited
performance equivalent to that of electroformed feeds: ~-0.2 dB insertion loss,
<-20 dB return loss from 120 GHz to 170 GHz, <-25 dB side lobes and <-23 dB
cross-polarization. We are currently fabricating a 50 mm diameter array with 84
horns consisting of 33 Si platelets as a prototype for the SPTpol and ACTpol
telescopes. Our fabrication facilities permit arrays up to 150 mm in diameter.Comment: 12 pages; SPIE proceedings for Millimeter, Submillimeter, and
Far-Infrared Detectors and Instrumentation for Astronomy V (Conference 7741,
June 2010, San Diego, CA, USA
Realism, Objectivity, and Evaluation
I discuss Benacerraf's epistemological challenge for realism about areas like mathematics, metalogic, and modality, and describe the pluralist response to it. I explain why normative pluralism is peculiarly unsatisfactory, and use this explanation to formulate a radicalization of Moore's Open Question Argument. According to the argument, the facts -- even the normative facts -- fail to settle the practical questions at the center of our normative lives. One lesson is that the concepts of realism and objectivity, which are widely identified, are actually in tension
Photon-noise limited sensitivity in titanium nitride kinetic inductance detectors
We demonstrate photon-noise limited performance at sub-millimeter wavelengths
in feedhorn-coupled, microwave kinetic inductance detectors (MKIDs) made of a
TiN/Ti/TiN trilayer superconducting film, tuned to have a transition
temperature of 1.4~K. Micro-machining of the silicon-on-insulator wafer
backside creates a quarter-wavelength backshort optimized for efficient
coupling at 250~\micron. Using frequency read out and when viewing a variable
temperature blackbody source, we measure device noise consistent with photon
noise when the incident optical power is ~0.5~pW, corresponding to noise
equivalent powers ~3 W/. This
sensitivity makes these devices suitable for broadband photometric applications
at these wavelengths
Combined Weekly Coordinate Solutions from SLR and DORIS
In International Terrestrial Reference Frame (ITRF) 2005 and ITRF2008, the approach for the construction of solutions by the IERS has been for individual analysis centers of each technique to process geodetic tracking data, and for each technique to develop a solution (or contribution) that is integrated into the final ITRF solution by careful combination of the technique solutions. The connections between the geodetic networks are realized by the application of local ties. In an alternate approach, we may assure processing homogeneity by creating normal equations for different techniques with the same orbit determination software, using identically derived algorithms. Another derivative of this approach is to realize the ties between the techniques using satellites tracked with multiple techniques; in effect tieing the networks together using satellite dynamics. In this solution, we develop a time series and a set of cumulative solutions from Satellite Laser Ranging (SLR) & Doppler Orbitography and Radio-positioning Integrated by Satellite (DORIS) based on homogeneous processing with the NASA GEODYN precise orbit determination suite of programs, where we jointly combine weekly the SLR data to Lageos1, Lageos2, Starlette, and Stella with the DORIS data from SPOT2-SPOT5, as well as satellites that utilize both techniques (TOPEX/Poseidon, Envisat, Jason-2). We discuss the modeling that is applied including upgrades implemented since the submission of the GSC ITRF2008 contributions for IDS. Firstly, we compare the SLR-only solutions comprising four geodetic satellites with the standard approach of utilizing only Lageos1 & Lageos2. Secondly, we evaluate the impact on the DORIS coordinates of the joint analysis with the SLR data
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