15,399 research outputs found
Tuttujen ruokaperunalajikkeiden suosio jatkuu
Viime vuonna neljä suosituinta ruokaperunalajiketta, Van Gogh, Nicola, Timo ja Asterix, kattoivat yhdessä lähes 60 % ruoka- ja varhaisperunan viljelypinta-alasta. Ruokateollisuuden tarpeisiin viljeltävistä lajikkeista Fambo ja Asterix kattoivat kolmanneksen ruokateollisuuslajikkeiden kokonaispinta-alasta. Lajikelistalle tuli kolme uutta ruokaperunalajiketta: Maatalouskeskon edustamat Appell ja Fontane sekä Siemenperunakeskukselta sinivioletti Blue Congo.vo
Study of shock waves generation, hot electron production and role of parametric instabilities in an intensity regime relevant for the shock ignition
We present experimental results at intensities relevant to Shock Ignition
obtained at the sub-ns Prague Asterix Laser System in 2012 . We studied shock waves
produced by laser-matter interaction in presence of a pre-plasma. We used a first beam at
1ω (1315 nm) at 7 × 10 13 W/cm 2 to create a pre-plasma on the front side of the target and
a second at 3ω (438 nm) at ∼ 10 16 W/cm 2 to create the shock wave. Multilayer targets
composed of 25 (or 40 μm) of plastic (doped with Cl), 5 μm of Cu (for Kα diagnostics)
and 20 μm of Al for shock measurement were used. We used X-ray spectroscopy of Cl
to evaluate the plasma temperature, Kα imaging and spectroscopy to evaluate spatial and
spectral properties of the fast electrons and a streak camera for shock breakout measurements.
Parametric instabilities (Stimulated Raman Scattering, Stimulated Brillouin Scattering and
Two Plasmon Decay) were studied by collecting the back scattered light and analysing its
spectrum. Back scattered energy was measured with calorimeters. To evaluate the maximum
pressure reached in our experiment we performed hydro simulations with CHIC and DUED
codes. The maximum shock pressure generated in our experiment at the front side of the
target during laser-interaction is 90 Mbar. The conversion efficiency into hot electrons was
estimated to be of the order of ∼ 0.1% and their mean energy in the order ∼50 keV.
Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distributio
ROSAT observations of the dwarf starforming galaxy Holmerg II (UGC 4305)
We present ROSAT PSPC and HRI observations of the dwarf irregular galaxy
Holmberg II (UGC4305). This is one of the most luminous dwarf galaxies (Lx~
10^{40} erg s^{-1} cm^{-2}) detected in the ROSAT All-Sky Survey. The X-ray
emission comes from a single unresolved point source, coincident with a large
HII region which emits intense radio emission. The source is variable on both
year and day timescales, clearly favouring accretion into a compact object
rather than a supernova remnant or a superbubble interpretation for the origin
of the X-ray emission. However, its X-ray spectrum is well-fit by a a
Raymond-Smith spectrum with kT~0.8 keV, lower than the temperature of X-ray
binaries in nearby spiral galaxies.Comment: Accepted for publication in MNRA
Reuse of Neural Modules for General Video Game Playing
A general approach to knowledge transfer is introduced in which an agent
controlled by a neural network adapts how it reuses existing networks as it
learns in a new domain. Networks trained for a new domain can improve their
performance by routing activation selectively through previously learned neural
structure, regardless of how or for what it was learned. A neuroevolution
implementation of this approach is presented with application to
high-dimensional sequential decision-making domains. This approach is more
general than previous approaches to neural transfer for reinforcement learning.
It is domain-agnostic and requires no prior assumptions about the nature of
task relatedness or mappings. The method is analyzed in a stochastic version of
the Arcade Learning Environment, demonstrating that it improves performance in
some of the more complex Atari 2600 games, and that the success of transfer can
be predicted based on a high-level characterization of game dynamics.Comment: Accepted at AAAI 1
- …
