5,917 research outputs found
Motion Deblurring in the Wild
The task of image deblurring is a very ill-posed problem as both the image
and the blur are unknown. Moreover, when pictures are taken in the wild, this
task becomes even more challenging due to the blur varying spatially and the
occlusions between the object. Due to the complexity of the general image model
we propose a novel convolutional network architecture which directly generates
the sharp image.This network is built in three stages, and exploits the
benefits of pyramid schemes often used in blind deconvolution. One of the main
difficulties in training such a network is to design a suitable dataset. While
useful data can be obtained by synthetically blurring a collection of images,
more realistic data must be collected in the wild. To obtain such data we use a
high frame rate video camera and keep one frame as the sharp image and frame
average as the corresponding blurred image. We show that this realistic dataset
is key in achieving state-of-the-art performance and dealing with occlusions
Effect of flood basalt stratigraphy on seismic waveforms recorded offshore Faroe Islands
The generation of short-period multiples between highly heterogeneous layers of basalt flows can strongly alter transmitted seismic wavefields. These layers filter and modify penetrating waves, producing apparent attenuation and phase changes in the observed waveforms. We investigated the waveform and apparent phase changes of the primary seismic signal using mainly the maximum kurtosis approach. We compared the seismic recordings from two short-offset vertical seismic profiles (VSPs) with synthetic seismograms, generated from sonic logs in the same wells, and we found that short-period multiples cause a rapid broadening of the primary arrivals and strong apparent phase changes within a short depth interval below the top of the basalt flows. Relatively large uncertainties were associated with estimating constant phase shifts of the seismic arrivals within the topmost 250 m of the basalt sequences, where complex scattering occurred. Within this interval of the Brugdan I well, a phase-only compensation of the first arrivals with a frequency-independent, combined scattering, and intrinsic attenuation operator was unfeasible. At a greater depth, we found that the phase shifts, predicted by a VSP-derived effective Q value, were similar to those estimated from the VSP signals using the kurtosis method. Thus, phase-only compensation with a combined scattering and intrinsic attenuation operator could work well depending on the seismic signal bandwidth and the distribution, depth, and magnitude of the impedance contrasts in the basalt sequence
Erosive potential of rains in the climate change scenarios in the upper Taquari River Basin, MS, Brazil.
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Resonant Production of Scalar Diquarks at the Next Generation Electron-Positron Colliders
We investigate the potential of TESLA and JLC/NLC electron-positron linear
collider designs to observe diquarks produced resonantly in processes involving
hard photons.Comment: 14 pages, 8 figures, coded in RevTEX, uses epsfi
Local Berry curvature signatures in dichroic angle-resolved photoelectron spectroscopy from two-dimensional materials
Topologically nontrivial two-dimensional materials hold great promise for next-generation optoelectronic applications. However, measuring the Hall or spin-Hall response is often a challenge and practically limited to the ground state. An experimental technique for tracing the topological character in a differential fashion would provide useful insights. In this work, we show that circular dichroism angle-resolved photoelectron spectroscopy provides a powerful tool that can resolve the topological and quantum-geometrical character in momentum space. In particular, we investigate how to map out the signatures of the momentum-resolved Berry curvature in two-dimensional materials by exploiting its intimate connection to the orbital polarization. A spin-resolved detection of the photoelectrons allows one to extend the approach to spin-Chern insulators. The present proposal can be extended to address topological properties in materials out of equilibrium in a time-resolved fashion
How Circular Dichroism in Time- A nd Angle-Resolved Photoemission Can Be Used to Spectroscopically Detect Transient Topological States in Graphene
Pumping graphene with circularly polarized light is the archetype of light-tailoring topological bands. Realizing the induced Floquet-Chern-insulator state and demonstrating clear experimental evidence for its topological nature has been a challenge, and it has become clear that scattering effects play a crucial role. We tackle this gap between theory and experiment by employing microscopic quantum kinetic calculations including realistic electron-electron and electron-phonon scattering. Our theory provides a direct link to the build up of the Floquet-Chern-insulator state in light-driven graphene and its detection in time- A nd angle-resolved photoemission spectroscopy (ARPES). This approach allows us to study the robustness of the Floquet features against dephasing and thermalization effects. We also discuss the ultrafast Hall response in the laser-heated state. Furthermore, the induced pseudospin texture and the associated Berry curvature give rise to momentum-dependent orbital magnetization, which is reflected in circular dichroism in ARPES (CD-ARPES). Combining our nonequilibrium calculations with an accurate one-step theory of photoemission allows us to establish a direct link between the build up of the topological state and the dichroic pump-probe photoemission signal. The characteristic features in CD-ARPES are shown to be stable against heating and dephasing effects. Thus, tracing circular dichroism in time-resolved photoemission provides new insights into transient topological properties
The High E_T Drop of J/psi to Drell-Yan Ratio from the Statistical c anti-c Coalescence Model
The dependence of the J/psi yield on the transverse energy E_T in heavy ion
collisions is considered within the statistical c anti-c coalescence model. The
model fits the NA50 data for Pb+Pb collisions at the CERN SPS even in the
high-E_T region (E_T > 100 GeV). Here E_T-fluctuations and E_T-losses in the
dimuon event sample naturally create the celebrated drop in the J/psi to
Drell-Yan ratio.Comment: 14 pages, REVTeX, 1 PS-figure. v2: References are corrected and
update
Wood furniture components: Implementation of flow-line technology based on lean manufacturing concepts
This case study is #3 in a series of studies that relate specifically to the development and application of lean manufacturing techniques for the furniture and wood component supplying industries. Case study #3 is an example of how productivity can be increased in a furniture manufacturing organization by using flow-line technology.
This case study provides information about lean manufacturing and how a lean manufacturing system can be implemented, followed by a detailed case study of a wood component manufacturing company’s adoption of a new flow-line technology based on lean manufacturing concepts
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