3,349 research outputs found
Real-World Normal Map Capture for Nearly Flat Reflective Surfaces
Although specular objects have gained interest in recent
years, virtually no approaches exist for markerless reconstruction
of reflective scenes in the wild. In this work, we
present a practical approach to capturing normal maps in
real-world scenes using video only. We focus on nearly planar
surfaces such as windows, facades from glass or metal,
or frames, screens and other indoor objects and show how
normal maps of these can be obtained without the use of an
artificial calibration object. Rather, we track the reflections
of real-world straight lines, while moving with a hand-held
or vehicle-mounted camera in front of the object. In contrast
to error-prone local edge tracking, we obtain the reflections
by a robust, global segmentation technique of an
ortho-rectified 3D video cube that also naturally allows efficient
user interaction. Then, at each point of the reflective
surface, the resulting 2D-curve to 3D-line correspondence
provides a novel quadratic constraint on the local surface
normal. This allows to globally solve for the shape by integrability
and smoothness constraints and easily supports
the usage of multiple lines. We demonstrate the technique
on several objects and facades
Tailoring Extension Efforts for Promotion of Diversified Crop Rotation Systems
We conducted a survey in the northern Great Plains to better understand farmer-preferred learning sources and formats, influential factors, and challenges related to adoption of diversified crop rotation systems. University Extension was ranked as the second most preferred learning source, lagging only behind other farmers. Most farmers listed short seminars and Extension fact sheets as their most preferred learning formats, and most viewed crop productivity and soil health as the most influential factors for new-practice adoption. Our findings can help Extension educators better facilitate future adoption of diversified cropping systems as a conservation practice
LOW AND INTERMEDIATE ENERGY HEAVY ION COLLISIONS IN THE SEMI-CLASSICAL MICROSCOPIC DESCRIPTION
It is shown how peripheral and central heavy-ion collisions can be described by Landau-Vlasov dynamics. For peripheral collisions at intermediate energies, mass-mass correlations, ejectile mean energies and angular distributions are obtained and compared with fragmentation data. For central collisions, one shows that the collision term destroys the TDHF property of transparency at low impact parameters for collisions close from the Coulomb barrier. Above 20 MeV/u incomplete fusion is described with associated linear momentum transfer and nuclear deformations. One exhibits how coupling to the continuum is obtained in Vlasov and Landau-Vlasov dynamics. Coulomb interaction being taken into account, we present also results concerning the isospin transfer and the excitation of the isovector dipole mode near and well above the Coulomb barrier. Some perspectives to further studies of physical observables are finally drawn
Towards two-dimensional metallic behavior at LaAlO3/SrTiO3 interfaces
Using a low-temperature conductive-tip atomic force microscope in
cross-section geometry we have characterized the local transport properties of
the metallic electron gas that forms at the interface between LaAlO3 and
SrTiO3. At low temperature, we find that the carriers do not spread away from
the interface but are confined within ~10 nm, just like at room temperature.
Simulations taking into account both the large temperature and electric-field
dependence of the permittivity of SrTiO3 predict a confinement over a few nm
for sheet carrier densities larger than ~6 10^13 cm-2. We discuss the
experimental and simulations results in terms of a multi-band carrier system.
Remarkably, the Fermi wavelength estimated from Hall measurements is ~16 nm,
indicating that the electron gas in on the verge of two-dimensionality.Comment: Accepted for publication in Physical Review Letter
Potential energy curves and spin-orbit coupling of light alkali-heavy rare gas molecules
The potential energy curves of the X, A, and B states of alkali-rare gas diatomic molecules, MKr and MXe, are investigated for M = Li, Na, K. The molecular spin-orbit coefficients a(R) = 〈2Π 1/2|ĤSO|2Π1/2〉 and b(R) = 〈2Π-1/2|ĤSO| 2Σ1/2〉 are calculated as a function the interatomic distance R. We show that a(R) increases and b(R) decreases as R decreases. This effect becomes less and less important as the mass of the alkali increases. A comparison of the rovibrational properties deduced from our calculations with experimental measurements recorded for NaKr and NaXe shows the quality of the calculation
Full oxide heterostructure combining a high-Tc diluted ferromagnet with a high-mobility conductor
We report on the growth of heterostructures composed of layers of the
high-Curie temperature ferromagnet Co-doped (La,Sr)TiO3 (Co-LSTO) with
high-mobility SrTiO3 (STO) substrates processed at low oxygen pressure. While
perpendicular spin-dependent transport measurements in STO//Co-LSTO/LAO/Co
tunnel junctions demonstrate the existence of a large spin polarization in
Co-LSTO, planar magnetotransport experiments on STO//Co-LSTO samples evidence
electronic mobilities as high as 10000 cm2/Vs at T = 10 K. At high enough
applied fields and low enough temperatures (H < 60 kOe, T < 4 K) Shubnikov-de
Haas oscillations are also observed. We present an extensive analysis of these
quantum oscillations and relate them with the electronic properties of STO, for
which we find large scattering rates up to ~ 10 ps. Thus, this work opens up
the possibility to inject a spin-polarized current from a high-Curie
temperature diluted oxide into an isostructural system with high-mobility and a
large spin diffusion length.Comment: to appear in Phys. Rev.
Irreducible characters of GSp(4, q) and dimensions of spaces of fixed vectors
In this paper, we compute the conjugacy classes and the list of irreducible
characters of GSp(4,q), where q is odd. We also determine precisely which
irreducible characters are non-cuspidal and which are generic. These characters
are then used to compute dimensions of certain subspaces of fixed vectors of
smooth admissible non-supercuspidal representations of GSp(4,F), where F is a
non-archimedean local field of characteristic zero with residue field of order
q.Comment: 48 pages, 21 tables. Corrected an error in Table 16 for type V*
representations (theta_11 and theta_12 were switched
Uniqueness of Bessel models: the archimedean case
In the archimedean case, we prove uniqueness of Bessel models for general
linear groups, unitary groups and orthogonal groups.Comment: 22 page
Participatory integrated coastal zone management in Vietnam: theory versus practice case study: Thua Thien Hue province
Sustainable management processes have undergone a shift from a top-down approach to a bottom-up approach. This bottom-up approach allows for a more apprehensive inclusion of stakeholders. In traditional hierarchical societies a combination of both is considered more desirable. This combination is described as a participatory approach that allows for bi-directional knowledge sharing. The question asked is whether this theoretical approach is viable in practice, taking into account different social, political and cultural influences. Qualitative research in bi-directional knowledge sharing and stakeholder participation in Integrated Coastal Zone Management (ICZM) was conducted in the provinces of Thua Thien Hue in Vietnam. Qualitative research was conducted using coding analysis. This analysis showed that in practice a great reluctance for change affects the implementation of ICZM. This reluctance is directly related to the level of power of stakeholders and the level to which stakeholders are embedded in the top-down tradition. Two contradicting results emerged. On the one hand the theoretical understanding of participatory ICZM is highest when reluctance for change is highest and vice versa. On the other hand a decrease in power results in an increase of the sustainability of the implementation of participatory ICZM. This research concluded that a ‘platform or structure’ is essential to achieve sustainability. In the Vietnamese context the tradition of power results in a platform which is both formal and non-formal. A non-formal platform is needed to create social capital, whereas a formal platform will limit the risk for arbitrariness and allow for institutionalisation
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