Marion Jaeger

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We investigated the performance of a neural network for derivation of the absorption coefficient of the brain from simulated non-invasive time-resolved reflectance measurements on the head. A five-layered geometry was considered assuming that the optical properties (except the absorption coefficient of the brain) and the thickness of all layers were known(More)
We describe a fully automated setup which is based on measurements of the spatially resolved reflectance for the determination of the reduced scattering and absorption coefficients in semi-infinite turbid media. The sample is illuminated with a xenon light source in combination with a monochromator enabling the scan of the wavelength from 450 nm to 950 nm.(More)
We determined the optical properties of turbid media from simulated spatially resolved reflectance (SRR) curves using an artificial neural network (ANN). In order to improve the performance of our method, multiple ANNs were applied for this problem. First, Monte Carlo (MC) simulations were performed using random optical properties which are relevant for(More)
The in-vivo optical properties of the human head are investigated in the 600-1100 nm range on different subjects using continuous wave and time domain diffuse optical spectroscopy. The work was performed in collaboration with different research groups and the different techniques were applied to the same subject. Data analysis was carried out using(More)
The effects of turbulence on the mixing of gases and dust in the outer Solar nebula are examined using 3-D MHD calculations in the shearing-box approximation with vertical stratification. The turbulence is driven by the magnetorotational instability. The magnetic and hydrodynamic stresses in the turbulence correspond to an accretion time at the midplane(More)
New multilayer polymer waveguides have been introduced with inverted nonlinear layers for efficient modal dispersion phase-matched second-harmonic generation at the telecommunication wavelength near 1.55 mm. The nonlinear optical core of the waveguides consists of two modified Disperse Red 1–based side-chain polymers with different glass-transition(More)
The excitation function of the reaction (22)Ne(alpha,n)(25)Mg, the key neutron source in the astrophysical s process in massive stars, has been determined from threshold at E(alpha) = 570 up to 1450 keV with an experimental sensitivity of 10(-11) b. For all resonances in this energy range new resonance parameters have been measured. For a possible resonance(More)
The optical properties of turbid media were calculated from the curvature at the radial distance ρ(O) and the slope at the radial distance ρ* of simulated spatially resolved reflectance curves (ρ(O) (ρ*) denotes a decrease of the spatially resolved reflectance curve of 0.75 (2.4) orders of magnitude relative to the reflectance value at 1.2 mm). We found(More)