2,324 research outputs found
Trajectory-Based Dynamic Map Labeling
In this paper we introduce trajectory-based labeling, a new variant of
dynamic map labeling, where a movement trajectory for the map viewport is
given. We define a general labeling model and study the active range
maximization problem in this model. The problem is NP-complete and W[1]-hard.
In the restricted, yet practically relevant case that no more than k labels can
be active at any time, we give polynomial-time algorithms. For the general case
we present a practical ILP formulation with an experimental evaluation as well
as approximation algorithms.Comment: 19 pages, 7 figures, extended version of a paper to appear at ISAAC
201
The pathological physiology of Gaigeria pachyscelis infestation
In two experiments, sheep under controlled conditions were artificially infested with the hookworm Gaigeria pachyscelis Railliet & Henry, 1910.
The effects of the helminth infestation on the host's metabolism were monitored by a series of blood, chemical and enzyme analyses.
Significant changes recorded were the development of a macrocytic normochromic anaemia, hypoproteinaemia,
hypocalcaemia, hyperglycaemia and eosinophilia.
The disease and death of some of the sheep were due primarily to loss of blood.The journals have been scanned in colour with a HP 5590 scanner; 600 dpi. Adobe Acrobat v.11 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format
Koinzidenz von Patientenverfügung und Zustimmung zur Organspende: was wünschen die Betroffenen? Eine Befragung deutscher Senioren [Coincidence of Advance Directive and Organ Donor Consent: What Do The Persons Concerned Want? A Survey of German Elderly Citizens]
In the case of acute brain injury, decision-making uncertainties can arise when both an advance decision to refuse treatment and a prior consent to post-mortem organ donation are present. It is yet unknown how the persons concerned view this potential conflict. The present study aims to investigate how frequent this situation is, whether the persons concerned are aware of the potential conflict and what they would prioritize.
Semi-quantitative cross-sectional survey of senior citizens of a metropolitan region in Germany using a literature-based questionnaire.
A total of 236 senior citizens participated in the survey, amounting to 52% of those invited. While 54% of the participants reported to have written advance directives, 46% had expressed their consent to post-mortem organ donation in written or oral form. Altogether, 29% of all participants had issued both types of written documents. The consent to organ donation correlated significantly with the presence of an advance directive. Only 47% of the advance directives contained, according to their authors, statements about organ donation. Dying outside of intensive care was the priority for 51%, while 17% favored donating their organs. About half of the participants accepted transient intensive care measures in the case of presumed or expected brain death, but only a fourth also accepted cardiopulmonary resuscitation in those situations. Knowledge about brain death was scant and the attitudes towards it were rather critical.
The coincidence of advance directives and organ donation consent is not uncommon in senior citizens and could contribute to low organ donation rates. The heterogeneous attitudes of the surveyed persons as well as their poor knowledge about brain death and the potential conflict studied here underscore the necessity of a high-quality advance care planning process
Equivalent thermo-mechanical parameters for perfect crystals
Thermo-elastic behavior of perfect single crystal is considered. The crystal
is represented as a set of interacting particles (atoms). The approach for
determination of equivalent continuum values for the discrete system is
proposed. Averaging of equations of particles' motion and long wave
approximation are used in order to make link between the discrete system and
equivalent continuum. Basic balance equations for equivalent continuum are
derived from microscopic equations. Macroscopic values such as Piola and Cauchy
stress tensors and heat flux are represented via microscopic parameters.
Connection between the heat flux and temperature is discussed. Equation of
state in Mie-Gruneisen form connecting Cauchy stress tensor with deformation
gradient and thermal energy is obtained from microscopic considerations.Comment: To be published in proceedings of IUTAM Simposium on "Vibration
Analysis of Structures with Uncertainties", 2009; 14 pages
Sputter Deposition of Semiconductor Superlattices for Thermoelectric Applications
Theoretical dramatic improvement of the thermoelectric properties of materials by using quantum confinement in novel semiconductor nanostructures has lead to considerable interest in the thermoelectric community. Therefore, we are exploring the critical materials issues for fabrication of quantum confined structures by magnetron sputtering in the lead telluride and bismuth telluride families of materials. We have synthesized modulated structures from thermoelectric materials with bilayer periods of as little as 3.2 nm and shown that they are stable at deposition temperatures high enough to grow quality films. Issues critical to high quality film growth have been investigated such as nucleation and growth conditions and their effect on crystal orientation and growth morphology. These investigations show that nucleating the film at a temperature below the growth temperature of optimum electronic properties produces high quality films. Our work with sputter deposition, which is inherently a high rate deposition process, builds the technological base necessary to develop economical production of these advanced materials. High deposition rate is critical since, even if efficiencies comparable with CFC based refrigeration systems can be achieved, large quantities of quantum confined materials will be necessary for cost-competitive uses
Hydrogen incorporation during deposition of a-Si:H from an intense source of SiH3
The incorporation of hydrogen during the fast deposition of a-Si:H from an expanding thermal arc is investigated by means of isotope labeling of the precursor gases silane and hydrogen. It is found that hydrogen in a-Si:H originates dominantly from the silyl radical. A small fraction of the hydrogen in a-Si:H is due to exchange reaction of atomic hydrogen in the plasma with hydrogen chemisorbed on the surface during growth.</p
Critical point network for drainage between rough surfaces
In this paper, we present a network method for computing two-phase flows between two rough surfaces with significant contact areas. Low-capillary number drainage is investigated here since one-phase flows have been previously investigated in other contributions. An invasion percolation algorithm is presented for modeling slow displacement of a wetting fluid by a non wetting one between two rough surfaces. Short-correlated Gaussian process is used to model random rough surfaces.The algorithm is based on a network description of the fracture aperture field. The network is constructed from the identification of critical points (saddles and maxima) of the aperture field. The invasion potential is determined from examining drainage process in a flat mini-channel. A direct comparison between numerical prediction and experimental visualizations on an identical geometry has been performed for one realization of an artificial fracture with a moderate fractional contact area of about 0.3. A good agreement is found between predictions and observations
Energy levels and far-infrared spectroscopy for two electrons in a semiconductor nanoring
The effects of electron-electron interaction of a two-electron nanoring on
the energy levels and far-infrared (FIR) spectroscopy have been investigated
based on a model calculation which is performed within the exactly numerical
diagonalization. It is found that the interaction changes the energy spectra
dramatically, and also shows significant influence on the FIR spectroscopy. The
crossings between the lowest spin-singlet and triplet states induced by the
coulomb interaction are clearly revealed. Our results are related to the
experiment recently carried out by A. Lorke et al. [Phys. Rev. Lett. 84, 2223
(2000)].Comment: 17 pages, 6 figures, revised and accepted by Phys. Rev. B (Dec. 15
Near-Limb Zeeman and Hanle Diagnostics
"Weak" magnetic-field diagnostics in faint objects near the bright solar disk
are discussed in terms of the level of non-object signatures, in particular, of
the stray light in telescopes. Calculated dependencies of the stray light
caused by diffraction at the 0.5-, 1.6-, and 4-meter entrance aperture are
presented. The requirements for micro-roughness of refractive and reflective
primary optics are compared. Several methods for reducing the stray light (the
Lyot coronagraphic technique, multiple stages of apodizing in the focal and
exit pupil planes, apodizing in the entrance aperture plane with a special
mask), and reducing the random and systematic errors are noted. An acceptable
level of stray light in telescopes is estimated for the V-profile recording
with a signal-to-noise ratio greater than three. Prospects for the limb
chromosphere magnetic measurements are indicated.Comment: 11 pages, 3 figure
First imaging results from the Iapetus B/C flyby of the Cassini spacecraft
Cassini had a relatively close flyby at Iapetus on New Year's Eve 2005. The 288 ISS images set various constraints on the origin theories of the dark/bright dichotomy, as revealed multiple surface structures at up to 740 m/pxl size
- …