11,042 research outputs found
Microcomputer system for medium-sized and experimental finite element analysis
The development of a microcomputer system is described. A series of finite element analysis programs are evaluated in terms of their cost effective application within the microcomputer system. It is shown that the system is practically maintenance free and can be sustained by individual laboratories of standard scale in the educational or academic environment
Star Formation and Dust Extinction Properties of Local Galaxies as seen from AKARI and GALEX
An accurate estimation of the star formation-related properties of galaxies
is crucial for understanding the evolution of galaxies. In galaxies,
ultraviolet (UV) light emitted by recently formed massive stars is attenuated
by dust, which is also produced by star formation (SF) activity, and is
reemitted at mid- and far- infrared (IR) wavelengths. In this study, we
investigate the star formation rate (SFR) and dust extinction using UV and IR
data. We selected local galaxies which are detected at AKARI FIS 90 um and
matched the IRAS IIFSCz 60 um select catalog. We measured FUV and NUV flux
densities from GALEX images. We examined the SF and extinction of Local
galaxies using four bands of AKARI. Then, we calculated FUV and total IR
luminosities, and obtained the SF luminosity, L_{SF}, the total luminosity
related to star formation activity, and the SFR. We find that in most galaxies,
L_{SF} is dominated by L_{dust}. We also find that galaxies with higher SF
activity have a higher fraction of their SF hidden by dust. In fact, the SF of
galaxies with SFRs >20 M_{sun}/yr is almost completely hidden by dust. Our
results boast a significantly higher precision with respect to previously
published works, due to the use of much larger object samples from the AKARI
and GALEX all sky surveys.Comment: 9 pages, 12 figures, accepted for publication in Earth, Planets, and
Space, A few minor corrections, and a reference adde
Isospin dependent kaon and antikaon optical potentials in dense hadronic matter
Isospin effects on the optical potentials of kaons and antikaons in dense
hadronic matter are investigated using a chiral SU(3) model. These effects are
important for asymmetric heavy ion collision experiments. In the present work
the dispersion relations are derived for kaons and antikaons, compatible with
the low energy scattering data, within our model approach. The relations result
from the kaonic interactions with the nucleons, vector mesons and scalar mesons
in the asymmetric nuclear matter. The isospin asymmetry effects arising from
the interactions with the vector-isovector - meson as well as the scalar
isovector mesons are considered. The density dependence of the isospin
asymmetry is seen to be appreciable for the kaon and antikaon optical
potentials. This can be particularly relevant for the future accelerator
facility FAIR at GSI, where experiments using neutron rich beams are planned to
be used in the study of compressed baryonic matter.Comment: 21 pages, 7 figure
Identifying cross country skiing techniques using power meters in ski poles
Power meters are becoming a widely used tool for measuring training and
racing effort in cycling, and are now spreading also to other sports. This
means that increasing volumes of data can be collected from athletes, with the
aim of helping coaches and athletes analyse and understanding training load,
racing efforts, technique etc. In this project, we have collaborated with
Skisens AB, a company producing handles for cross country ski poles equipped
with power meters. We have conducted a pilot study in the use of machine
learning techniques on data from Skisens poles to identify which "gear" a skier
is using (double poling or gears 2-4 in skating), based only on the sensor data
from the ski poles. The dataset for this pilot study contained labelled
time-series data from three individual skiers using four different gears
recorded in varied locations and varied terrain. We systematically evaluated a
number of machine learning techniques based on neural networks with best
results obtained by a LSTM network (accuracy of 95% correctly classified
strokes), when a subset of data from all three skiers was used for training. As
expected, accuracy dropped to 78% when the model was trained on data from only
two skiers and tested on the third. To achieve better generalisation to
individuals not appearing in the training set more data is required, which is
ongoing work.Comment: Presented at the Norwegian Artificial Intelligence Symposium 201
Visibility and aerosol measurement by diode-laser random-modulation CW lidar
Examples of diode laser (DL) random-modulation continuous wave (RM-CW) lidar measurements are reported. The ability of the measurement of the visibility, vertical aerosol profile, and the cloud ceiling height is demonstrated. Although the data shown here were all measured at night time, the daytime measurement is, of course, possible. For that purpose, accurate control of the laser frequency to the center frequency of a narrow band filter is required. Now a new system with a frequency control is under construction
Observations of solar energetic particles at a synchronous orbit
The Space Environment Monitors (SEM) on board the Japanese geostationary meteorological satellites (GMS-1 and GMS-2) observed energetic protons, alpha particles and electrons continuously for February 1978 to September 1984. The satellites were at 6.6 Earth radii above 140 deg E equator
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