2,912 research outputs found
A Dynamic Programming Solution to Bounded Dejittering Problems
We propose a dynamic programming solution to image dejittering problems with
bounded displacements and obtain efficient algorithms for the removal of line
jitter, line pixel jitter, and pixel jitter.Comment: The final publication is available at link.springer.co
One More Awareness Gap? The BehaviourâImpact Gap Problem
Preceding research has made hardly any attempt to measure the ecological impacts of pro-environmental behaviour in an objective way. Those impacts were rather supposed or calculated. The research described herein scrutinized the ecological impact reductions achieved through pro-environmental behaviour and raised the question how much of a reduction in carbon footprint can be achieved through voluntary action without actually affecting the socio-economic determinants of life. A survey was carried out in order to measure the difference between the ecological footprint of âgreenâ and âbrownâ consumers. No significant difference was found between the ecological footprints of the two groupsâsuggesting that individual pro-environmental attitudes and behaviour do not always reduce the environmental impacts of consumption. This finding resulted in the formulation of a new proposition called the BIG (behaviourâimpact gap) problem, which is an interesting addition to research in the field of environmental awareness gaps
Applying consumer responsibility principle in evaluating environmental load of carbon emissions
There is a need for a proper indicator in order to assess the environmental impact of international
trade, therefore using the carbon footprint as an indicator can be relevant and useful. The aim of this
study is to show from a methodological perspective how the carbon footprint, combined with input-
output models can be used for analysing the impacts of international trade on the sustainable use
of national resources in a country. The use of the input-output approach has the essential advantage
of being able to track the transformation of goods through the economy. The study examines the environmental
impact of consumption related to international trade, using the consumer responsibility
principle. In this study the use of the carbon footprint and input-output methodology is shown on the
example of the Hungarian consumption and the impact of international trade. Moving from a production-
based approach in climate policy to a consumption-perspective principle and allocation,
would also help to increase the efficiency of emission reduction targets and the evaluation of the
ecological impacts of international trade
Tackling 3D ToF Artifacts Through Learning and the FLAT Dataset
Scene motion, multiple reflections, and sensor noise introduce artifacts in
the depth reconstruction performed by time-of-flight cameras. We propose a
two-stage, deep-learning approach to address all of these sources of artifacts
simultaneously. We also introduce FLAT, a synthetic dataset of 2000 ToF
measurements that capture all of these nonidealities, and allows to simulate
different camera hardware. Using the Kinect 2 camera as a baseline, we show
improved reconstruction errors over state-of-the-art methods, on both simulated
and real data.Comment: ECCV 201
PANIC: the new panoramic NIR camera for Calar Alto
PANIC is a wide-field NIR camera, which is currently under development for
the Calar Alto observatory (CAHA) in Spain. It uses a mosaic of four Hawaii-2RG
detectors and covers the spectral range from 0.8-2.5 micron(z to K-band). The
field-of-view is 30x30 arcmin. This instrument can be used at the 2.2m
telescope (0.45arcsec/pixel, 0.5x0.5 degree FOV) and at the 3.5m telescope
(0.23arcsec/pixel, 0.25x0.25 degree FOV). The operating temperature is about
77K, achieved by liquid Nitrogen cooling. The cryogenic optics has three flat
folding mirrors with diameters up to 282 mm and nine lenses with diameters
between 130 mm and 255 mm. A compact filter unit can carry up to 19 filters
distributed over four filter wheels. Narrow band (1%) filters can be used. The
instrument has a diameter of 1.1 m and it is about 1 m long. The weight limit
of 400 kg at the 2.2m telescope requires a light-weight cryostat design. The
aluminium vacuum vessel and radiation shield have wall thicknesses of only 6 mm
and 3 mm respectively.Comment: This paper has been presented in the SPIE of Astronomical Telescopes
and Instrumentation 2008 in Marseille (France
Gas-phase CO2 emission toward Cepheus A East: the result of shock activity?
We report the first detection of gas-phase CO2 emission in the star-forming
region Cepheus A East, obtained by spectral line mapping of the v2 bending mode
at 14.98 micron with the Infrared Spectrograph (IRS) instrument onboard the
Spitzer Space Telescope. The gaseous CO2 emission covers a region about 35'' x
25'' in extent, and results from radiative pumping by 15 micron continuum
photons emanating predominantly from the HW2 protostellar region. The gaseous
CO2 exhibits a temperature distribution ranging from 50 K to 200 K. A
correlation between the gas-phase CO2 distribution and that of H2 S(2), a
tracer of shock activity, indicates that the CO2 molecules originate in a cool
post-shock gas component associated with the outflow powered by HW2. The
presence of CO2 ice absorption features at 15.20 micron toward this region and
the lack of correlation between the IR continuum emission and the CO2 gas
emission distribution further suggest that the gaseous CO2 molecules are mainly
sputtered off grain mantles -- by the passage of slow non-dissociative shocks
with velocities of 15-30 km/s -- rather than sublimated through grain heating.Comment: 11 pages, 6 figures, accepted for publication in ApJ
Preliminary optical design of PANIC, a wide-field infrared camera for CAHA
In this paper, we present the preliminary optical design of PANIC (PAnoramic
Near Infrared camera for Calar Alto), a wide-field infrared imager for the
Calar Alto 2.2 m telescope. The camera optical design is a folded single
optical train that images the sky onto the focal plane with a plate scale of
0.45 arcsec per 18 micron pixel. A mosaic of four Hawaii 2RG of 2k x 2k made by
Teledyne is used as detector and will give a field of view of 31.9 arcmin x
31.9 arcmin. This cryogenic instrument has been optimized for the Y, J, H and K
bands. Special care has been taken in the selection of the standard IR
materials used for the optics in order to maximize the instrument throughput
and to include the z band. The main challenges of this design are: to produce a
well defined internal pupil which allows reducing the thermal background by a
cryogenic pupil stop; the correction of off-axis aberrations due to the large
field available; the correction of chromatic aberration because of the wide
spectral coverage; and the capability of introduction of narrow band filters
(~1%) in the system minimizing the degradation in the filter passband without a
collimated stage in the camera. We show the optomechanical error budget and
compensation strategy that allows our as built design to met the performances
from an optical point of view. Finally, we demonstrate the flexibility of the
design showing the performances of PANIC at the CAHA 3.5m telescope.Comment: This paper has been presented in the SPIE of Astronomical Telescopes
and Instrumentation 2008 in Marseille (France
Synchronous Counting and Computational Algorithm Design
Consider a complete communication network on nodes, each of which is a state machine. In synchronous 2-counting, the nodes receive a common clock pulse and they have to agree on which pulses are "odd" and which are "even". We require that the solution is self-stabilising (reaching the correct operation from any initial state) and it tolerates Byzantine failures (nodes that send arbitrary misinformation). Prior algorithms are expensive to implement in hardware: they require a source of random bits or a large number of states. This work consists of two parts. In the first part, we use computational techniques (often known as synthesis) to construct very compact deterministic algorithms for the first non-trivial case of . While no algorithm exists for , we show that as few as 3 states per node are sufficient for all values . Moreover, the problem cannot be solved with only 2 states per node for , but there is a 2-state solution for all values . In the second part, we develop and compare two different approaches for synthesising synchronous counting algorithms. Both approaches are based on casting the synthesis problem as a propositional satisfiability (SAT) problem and employing modern SAT-solvers. The difference lies in how to solve the SAT problem: either in a direct fashion, or incrementally within a counter-example guided abstraction refinement loop. Empirical results suggest that the former technique is more efficient if we want to synthesise time-optimal algorithms, while the latter technique discovers non-optimal algorithms more quickly
Uncovering the kiloparsec-scale stellar ring of NGC5128
We reveal the stellar light emerging from the kiloparsec-scale, ring-like
structure of the NGC5128 (Centaurus A) galaxy in unprecedented detail. We use
arcsecond-scale resolution near infrared images to create a "dust-free" view of
the central region of the galaxy, which we then use to quantify the shape of
the revealed structure. At the resolution of the data, the structure contains
several hundreds of discreet, point-like or slightly elongated sources. Typical
extinction corrected surface brightness of the structure is K_S = 16.5
mag/arcsec^2, and we estimate the total near infrared luminosity of the
structure to be M = -21 mag. We use diffraction limited (FWHM resolution of ~
0.1", or 1.6 pc) near infrared data taken with the NACO instrument on VLT to
show that the structure decomposes into thousands of separate, mostly
point-like sources. According to the tentative photometry, the most luminous
sources have M_K = -12 mag, naming them red supergiants or relatively low-mass
star clusters. We also discuss the large-scale geometry implied by the
reddening signatures of dust in our near infrared images.Comment: 5 pages, 4 figures, accepted for publication in A&A Letters. A
version with high resolution images can be downloaded from
http://www.helsinki.fi/~jtkainul/CenALette
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