919 research outputs found
A new automated workflow for 3D character creation based on 3D scanned data
In this paper we present a new workflow allowing the creation of 3D characters in an automated way that does not require the expertise of an animator. This workflow is based of the acquisition of real human data captured by 3D body scanners, which is them processed to generate firstly animatable body meshes, secondly skinned body meshes and finally textured 3D garments
On the Complexity of Case-Based Planning
We analyze the computational complexity of problems related to case-based
planning: planning when a plan for a similar instance is known, and planning
from a library of plans. We prove that planning from a single case has the same
complexity than generative planning (i.e., planning "from scratch"); using an
extended definition of cases, complexity is reduced if the domain stored in the
case is similar to the one to search plans for. Planning from a library of
cases is shown to have the same complexity. In both cases, the complexity of
planning remains, in the worst case, PSPACE-complete
Optical quenching and recovery of photoconductivity in single-crystal diamond
We study the photocurrent induced by pulsed-light illumination (pulse
duration is several nanoseconds) of single-crystal diamond containing nitrogen
impurities. Application of additional continuous-wave light of the same
wavelength quenches pulsed photocurrent. Characterization of the optically
quenched photocurrent and its recovery is important for the development of
diamond based electronics and sensing
Space Charge Limited 2-d Electron Flow between Two Flat Electrodes in a Strong Magnetic Field
An approximate analytic solution is constructed for the 2-d space charge
limited emission by a cathode surrounded by non emitting conducting ledges of
width Lambda. An essentially exact solution (via conformal mapping) of the
electrostatic problem in vacuum is matched to the solution of a linearized
problem in the space charge region whose boundaries are sharp due to the
presence of a strong magnetic field. The current density growth in a narrow
interval near the edges of the cathode depends strongly on Lambda. We obtain an
empirical formula for the total current as a function of Lambda which extends
to more general cathode geometries.Comment: 4 pages, LaTex, e-mail addresses: [email protected],
[email protected]
Surface-induced charge state conversion of nitrogen-vacancy defects in nanodiamonds
We present a study of the charge state conversion of single nitrogen-vacancy
(NV) defects hosted in nanodiamonds (NDs). We first show that the proportion of
negatively-charged NV defects, with respect to its neutral counterpart
NV, decreases with the size of the ND. We then propose a simple model
based on a layer of electron traps located at the ND surface which is in good
agreement with the recorded statistics. By using thermal oxidation to remove
the shell of amorphous carbon around the NDs, we demonstrate a significant
increase of the proportion of NV defects in 10-nm NDs. These results are
invaluable for further understanding, control and use of the unique properties
of negatively-charged NV defects in diamondComment: 6 pages, 4 figure
Quantitative comparison of within-sample heterogeneity scores for {DNA} methylation data
Spinel Harzburgite-Derived Silicate Melts Forming Sulfide-Bearing Orthopyroxenite in the Lithosphere. Part 1: Partition Coefficients and Volatile Evolution Accompanying Fluid- and Redox-Induced Sulfide Formation
We report abundances of major trace and volatile elements in an orthopyroxenite vein cutting a sub-arc, mantle-derived, spinel harzburgite xenolith from Kamchatka. The orthopyroxenite contains abundant sulfides and is characterized by the presence of glass (formerly melt) both interstitially and as inclusions in minerals, comparable with similar veins from the West Bismarck arc. The glass formed by quenching of residual melts following crystallization of abundant orthopyroxene, amphibole, and minor olivine and spinel. The interstitial glass has a low-Ti, high-Mg# andesite composition, with a wide range of H2O and S contents but more limited F and Cl variations. We calculate trace element partition coefficients using mineral and glass data, including those for halogens in amphibole, which agree with experimental results from the literature. Despite having a similar, high-Mg# andesite composition, the orthopyroxene-hosted glass inclusions usually contain much more H2O and S than the interstitial glass (4â7 wt% and âŒ2,600 ppm, respectively). The initial vein-forming melts were oxidized, recording oxygen fugacity conditions up to âŒ1.5 log units above the fayaliteâmagnetiteâquartz oxygen buffer. They intruded the sub-arc mantle lithosphere at â„1,300°C, where they partially crystallized to form high-Mg# andesitic derivative melts at ca. 1,050â1,100°C. Comparison with literature data on glass-free orthopyroxenite veins from Kamchatka and the glass-bearing ones from West Bismarck reveals fundamental similarities indicating common parental melts, which were originally produced by low-degree melting (â€5%) of spinel harzburgite at â„1,360°C and â€1.5 GPa. This harzburgite source likely contained â€0.05 wt% H2O and a few ppm of halogens. Volatile evolution inferred from glass compositions shows that (i) redox exchange between S6+ in the original melt and Fe2+ in the host mantle minerals, together with (ii) the formation of an S-bearing, (H2O, Cl)-rich hydrothermal fluid from the original melt, provides the conditions for the formation of abundant sulfides in the orthopyroxenites during cooling. During this process, up to 85% of the original melt S content (âŒ2,600 ppm) is locally precipitated as magmatic and hydrothermal sulfides. As such, melts derived from spinel harzburgite sources can concentrate chalcophile and highly siderophile metals in orthopyroxenite dykes and sills in the lithosphere
Measurement of the CMS Magnetic Field
The measurement of the magnetic field in the tracking volume inside the
superconducting coil of the Compact Muon Solenoid (CMS) detector under
construction at CERN is done with a fieldmapper designed and produced at
Fermilab. The fieldmapper uses 10 3-D B-sensors (Hall probes) developed at
NIKHEF and calibrated at CERN to precision 0.05% for a nominal 4 T field. The
precise fieldmapper measurements are done in 33840 points inside a cylinder of
1.724 m radius and 7 m long at central fields of 2, 3, 3.5, 3.8, and 4 T. Three
components of the magnetic flux density at the CMS coil maximum excitation and
the remanent fields on the steel-air interface after discharge of the coil are
measured in check-points with 95 3-D B-sensors located near the magnetic flux
return yoke elements. Voltages induced in 22 flux-loops made of 405-turn
installed on selected segments of the yoke are sampled online during the entire
fast discharge (190 s time-constant) of the CMS coil and integrated offline to
provide a measurement of the initial magnetic flux density in steel at the
maximum field to an accuracy of a few percent. The results of the measurements
made at 4 T are reported and compared with a three-dimensional model of the CMS
magnet system calculated with TOSCA.Comment: 4 pages, 5 figures, 15 reference
Apolipoprotein E (APOE) genotype regulates body weight and fatty acid utilizationâStudies in gene-targeted replacement mice
Scope Of the three human apolipoprotein E (APOE) alleles, the Δ3 allele is most common, which may be a result of adaptive evolution. In this study, we investigated whether the APOE genotype affects body weight and energy metabolism through regulation of fatty acid utilization. Methods and results Targeted replacement mice expressing the human APOE3 were significantly heavier on low- and high-fat diets compared to APOE4 mice. Particularly on high-fat feeding, food intake and dietary energy yields as well as fat mass were increased in APOE3 mice. Fatty acid mobilization determined as activation of adipose tissue lipase and fasting plasma nonesterified fatty acid levels were significantly lower in APOE3 than APOE4 mice. APOE4 mice, in contrast, exhibited higher expression of proteins involved in fatty acid oxidation in skeletal muscle. Conclusion Our data suggest that APOE3 is associated with the potential to more efficiently harvest dietary energy and to deposit fat in adipose tissue, while APOE4 carriers tend to increase fatty acid mobilization and utilization as fuel substrates especially under high-fat intake. The different handling of dietary energy may have contributed to the evolution and worldwide distribution of the Δ3 allele
High Efficiency Plastic Scintillator Detector with Wave-Length Shifting Fiber Readout for the GLAST Large Area Telescope
This paper describes the design and performance studies of the scintillator tile detectors for the Anti-Coincidence Detector (ACD) of the Large Area Telescope (LAT) on the Gamma ray Large Area Space Telescope (GLAST), scheduled for launch in early 2008. The scintillator tile detectors utilize wavelength shifting fibers and have dual photomultiplier tube (PMT) readout. The design requires highly efficient and uniform detection of singly charged relativistic particles over the tile area and must meet all requirements for a launch, as well as operation in a space environment. We present here the design of three basic types of tiles used in the ACD, ranging in size from approx.450 sq cm to approx.2500 sq cm, all 1 cm thick, with different shapes, and with photoelectron yield of approx. 20 photoelectrons per minimum ionizing particle (mip) at normal tile incidence, uniform over the tile area. Some tiles require flexible clear fiber cables up to 1.5 m long to deliver scintillator light to remotely located PMT
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