66 research outputs found
Virtopsy: Zukunftsträchtige Forschung in der Rechtsmedizin
Computed tomography techniques have been developed over the last 10 years and have found various applications in the forensic field. The most recent development is multislice computed tomography combined with photogrammetry-based surface optical scanning and image rendering techniques. This combination of techniques can be used to produce 3-dimensional images of injury patterns for comparison with suspect weapons and also to screen for pathological conditions in the living or deceased. This technology provides a minimally invasive procedure for capturing forensically relevant images which can be produced in the courtroom. The rapid developments in imaging techniques could provide an alternative to conventional autopsy procedures in the futur
Anderson localization in a periodic photonic lattice with a disordered boundary
We investigate experimentally the light evolution inside a two-dimensional
finite periodic array of weakly- coupled optical waveguides with a disordered
boundary. For a completely localized initial condition away from the surface,
we find that the disordered boundary induces an asymptotic localization in the
bulk, centered around the initial position of the input beam.Comment: 3 pages, 4 figure
Quantum chaos in an ultrastrongly coupled bosonic junction
The semiclassical and quantum dynamics of two ultrastrongly coupled nonlinear resonators cannot be explained using the discrete nonlinear Schrödinger equation or the Bose-Hubbard model, respectively. Instead, a model beyond the rotating wave approximation must be studied. In the semiclassical limit this model is not integrable and becomes chaotic for a finite window of parameters. For the quantum dimer we find corresponding regions of stability and chaos. The more striking consequence for both semiclassical and quantum chaos is that the tunneling time between the sites becomes unpredictable. These results, including the transition to chaos, can be tested in experiments with superconducting microwave resonators
Observation of the gradual transition from one-dimensional to two-dimensional Anderson localization
We study the gradual transition from one-dimensional to two-dimensional
Anderson localization upon transformation of the dimensionality of disordered
waveguide arrays. An effective transition from one- to two-dimensional system
is achieved by increasing the number of rows forming the arrays. We observe
that, for a given disorder level, Anderson localization becomes weaker with
increasing number of rows, hence the effective dimension.Comment: 4 pages, 3 figures, to appear in Optics Letter
Epidemiological impact of waning immunization on a vaccinated population
This is an epidemiological SIRV model based study that is de- signed to analyze the impact of vaccination in containing infection spread, in a 4-tiered population compartment comprised of susceptible, infected, recov- ered and vaccinated agents. While many models assume a lifelong protection through vaccination, we focus on the impact of waning immunization due to conversion of vaccinated and recovered agents back to susceptible ones. Two asymptotic states exist, the \disease-free equilibrium" and the \endemic equi- librium" and we express the transitions between these states as function of the vaccination and conversion rates and using the basic reproduction number. We nd that the vaccination of newborns and adults have dierent consequences on controlling an epidemic. Also, a decaying disease protection within the re- covered sub-population is not sucient to trigger an epidemic on the linear level. We perform simulations for a parameter set modelling a disease with waning immunization like pertussis. For a diusively coupled population, a transition to the endemic state can proceed via the propagation of a traveling infection wave, described successfully within a Fisher-Kolmogorov framework
Infection fronts in contact disease spread
87.23.Cc Population dynamics and ecological pattern formation, 87.10.Ed Ordinary differential equations (ODE), partial differential equations (PDE), integrodifferential models, 87.10.Mn Stochastic modeling,
ChemInform Abstract: Concave Reagents. Part 30. Diastereoselective Generation of Quaternary Stereocenters by Ligand-Controlled Palladium-Catalyzed Allylations
Observation Of Anomalous Diffusion In A 1D Optical Random Dimer
It is a popular belief that in one-dimensional (1D) systems the presence of any amount of disorder would lead to localized eigenstates - the so-called Anderson localization [1]. In contrast, a few theoretical counter-examples show that an amount of correlations in a disordered potential can lead to long-range transport. The prototypical case is the Random Dimer Model (RDM) [2] where in the context of a tight-binding Hamiltonian pairs of adjacent energy levels are assigned at random, leading to two-site correlations in an otherwise random lattice. © 2013 IEEE
Self-Trapping Threshold In Disordered Nonlinear Photonic Lattices
We investigate numerically and experimentally the influence of coupling disorder on the self-trapping dynamics in nonlinear one-dimensional optical waveguide arrays. The existence of a lower and upper bound of the effective average propagation constant allows for a generalized definition of the threshold power for the onset of soliton localization. When compared to perfectly ordered systems, this threshold is found to decrease in the presence of coupling disorder. © 2013 Optical Society of America
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