21,335 research outputs found
Development of a flexible test-bed for robotics, telemanipulation and servicing research
The development of a flexible operation test-bed, based around a commercially available ASEA industrial robot is described. The test-bed was designed to investigate fundamental human factors issues concerned with the unique problems of robotic manipulation in the hostile environment of Space
Sigma One
We demonstrate that it is possible to calculate not only the mean of an
underlying population but also its dispersion, given only a single observation
and physically reasonable constraints (i.e., that the quantities under
consideration are non-negative and bounded). We suggest that this
counter-intuitive conclusion is in fact at the heart of most modeling of
astronomical data.Comment: Accepted to the Astronomical Journal. 13 pages, 4 figure
Methods of calculating ionization energies of multielectron (five or more) isoelectronic atomic ions
We have previously used simple empirical equations to reproduce the literature values of the ionization energies of isoelectronic sequences of up to four electrons which gave very good agreement. We reproduce here a kinetic energy expression with corrections for relativity and Lamb shift effects which give excellent agreement with the literature values. These equations become more complex as the number of electrons in the system increases. Alternative simple quadratic expressions for calculating ionization energies of multielectron ions are discussed. A set of coefficients when substituted into a simple expression produces very good agreement with the literature values. Our work shows that Slater's rules are not appropriate for predicting trends or screening constants. This work provides very strong evidence that ionization energies are not functions of complete squares, and when calculating ionization energies electron transition/relaxation has to be taken into account. We demonstrate clearly that for particular isoelectronic sequences, the ionizing electrons may occupy different orbitals and in such cases more than one set of constants are needed to calculate the ionization energies
User evaluation outside the lab: the trial of Físchlár-News
A user study of Físchlár-News system was conducted in Spring 2004 with 16 users, each user using the system for a 1-month period. Físchlár-News is an experimental online news archive that incorporates various automatic content-based video indexing techniques and a news story recommender algorithm to process and index the daily 9 o’clock broadcast news from TV and allows its users to browse, search, be recommended, and play news stories on a conventional web browser. Pre and post-trial questionnaires, interaction logging and incident diary methods collected both qualitative and quantitative usage data during the trial period. While the details of the findings from this evaluation is reported elsewhere, in this paper we report the details of the methodology taken and our experience of conducting this evaluation
Transmit Antenna Selection for Physical-Layer Network Coding Based on Euclidean Distance
Physical-layer network coding (PNC) is now well-known as a potential
candidate for delay-sensitive and spectrally efficient communication
applications, especially in two-way relay channels (TWRCs). In this paper, we
present the error performance analysis of a multiple-input single-output (MISO)
fixed network coding (FNC) system with two different transmit antenna selection
(TAS) schemes. For the first scheme, where the antenna selection is performed
based on the strongest channel, we derive a tight closed-form upper bound on
the average symbol error rate (SER) with -ary modulation and show that the
system achieves a diversity order of 1 for . Next, we propose a
Euclidean distance (ED) based antenna selection scheme which outperforms the
first scheme in terms of error performance and is shown to achieve a diversity
order lower bounded by the minimum of the number of antennas at the two users.Comment: 15 pages, 4 figures, Globecom 2017 (Wireless Communications
Symposium
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