9,089 research outputs found
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
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
CONSERVATION AND RESTORATION OF NATURAL ENVIRONMENT OF WATERFRONT IN JAPAN
Article信州大学理学部付属諏訪臨湖実験所報告 7: 177-187(1991)departmental bulletin pape
Behavior of Li abundances in solar-analog stars II. Evidence of the connection with rotation and stellar activity
We previously attempted to ascertain why the Li I 6708 line-strengths of
Sun-like stars differ so significantly despite the superficial similarities of
stellar parameters. We carried out a comprehensive analysis of 118 solar
analogs and reported that a close connection exists between the Li abundance
A_Li and the line-broadening width (v_r+m; mainly contributed by rotational
effect), which led us to conclude that stellar rotation may be the primary
control of the surface Li content. To examine our claim in more detail, we
study whether the degree of stellar activity exhibits a similar correlation
with the Li abundance, which is expected because of the widely believed close
connection between rotation and activity. We measured the residual flux at the
line center of the strong Ca II 8542 line, r_0(8542), known to be a useful
index of stellar activity, for all sample stars using newly acquired spectra in
this near-IR region. The projected rotational velocity (v_e sin i) was
estimated by subtracting the macroturbulence contribution from v_r+m that we
had already established. A remarkable (positive) correlation was found in the
A_Li versus (vs.) r_0(8542) diagram as well as in both the r_0(8542) vs. v_e
sin i and A_Li vs. v_e sin i diagrams, as had been expected. With the
confirmation of rotation-dependent stellar activity, this clearly shows that
the surface Li abundances of these solar analogs progressively decrease as the
rotation rate decreases. Given this observational evidence, we conclude that
the depletion of surface Li in solar-type stars, probably caused by effective
envelope mixing, operates more efficiently as stellar rotation decelerates. It
may be promising to attribute the low-Li tendency of planet-host G dwarfs to
their different nature in the stellar angular momentum.Comment: 12 pages, 9 figures; accepted for publication in Astron. Astrophys
Innovative Leadership in Education: The Characteristics and Practices of the National Association of Secondary School Principals (NASSP) Digital Principals of the Year.
Ed.D. Thesis. University of Hawaiʻi at Mānoa 2017
Theory of the thermoelectricity of intermetallic compounds with Ce or Yb ions
The thermoelectric properties of intermetallic compounds with Ce or Yb ions
are explained by the single-impurity Anderson model which takes into account
the crystal-field splitting of the 4{\it f} ground-state multiplet, and assumes
a strong Coulomb repulsion which restricts the number of {\it f} electrons or
{\it f} holes to for Ce and for Yb ions. Using
the non-crossing approximation and imposing the charge neutrality constraint on
the local scattering problem at each temperature and pressure, the excitation
spectrum and the transport coefficients of the model are obtained. The
thermopower calculated in such a way exhibits all the characteristic features
observed in Ce and Yb intermetallics. Calculating the effect of pressure on
various characteristic energy scales of the model, we obtain the phase
diagram which agrees with the experimental data on CeRuSi,
CeCuSi, CePdSi, and similar compounds. The evolution of the
thermopower and the electrical resistance as a function of temperature,
pressure or doping is explained in terms of the crossovers between various
fixed points of the model and the redistribution of the single-particle
spectral weight within the Fermi window.Comment: 13 pages, 11 figure
Specific Heat and Superfluid Density for Possible Two Different Superconducting States in NaxCoO2.yH2O
Several thermodynamic measurements for the cobaltate superconductor,
NaxCoO2.yH2O, have so far provided results inconsistent with each other. In
order to solve the discrepancies, we microscopically calculate the temperature
dependences of specific heat and superfluid density for this superconductor. We
show that two distinct specific-heat data from Oeschler et al. and Jin et al.
are reproduced, respectively, for the extended s-wave state and the p-wave
state. Two different superfluid-density data are also reproduced for each case.
These support our recent proposal of possible two different pairing states in
this material. In addition, we discuss the experimentally proposed large
residual Sommerfeld coefficient and extremely huge effective carrier mass.Comment: 5 pages, 4 figures, Submitted to J. Phys. Soc. Jp
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