A new method for the determination of the real part of the elastic scattering amplitude is examined for high energy proton-proton and proton-nuclei elastic scattering at small momentum transfer. This method allows us to decrease the number of model assumptions, to obtain the real part in a narrow region of momentum transfer and to test different models for hadron-nuclei scattering. ∗Unité de Re...

We study a phenomenological model for the continuum emission of Seyfert galaxies. In this quasi-spherical accretion scenario, the central X-ray source is constituted by a hot spherical plasma region surrounded by spherically distributed cold dense clouds. The cold material is radiatively coupled with the hot thermal plasma. Assuming energy balance, we compute the hard X-ray spectral slope Γ and...

Displacement maps and procedural displacement shaders are a widely used approach of specifying geometric detail and increasing the visual complexity of a scene. While it is relatively straightforward to handle displacement shaders in pipeline based rendering systems such as the Reyes-architecture, it is much harder to efficiently integrate displacement-mapped surfaces in ray-tracers. Many comme...

Outdoor sound propagation benefits from algorithms that can handle, in a computationally efficient manner, inhomogeneous media, complex boundary surfaces, and large spatial expanse. One recent work by Mo, Yeh, Lin, and Manocha [Appl. Acoust. 104, 142-151 (2016)] proposed a ray tracing method using analytic ray curves as tracing primitives, which improved the performance of propagation paths com...

We study the effects of unparticle physics on the cosmic ray photon and e, including on the pair production (PP) and elastic scattering (ES) of cosmic ray photon off various background radiations, and on the inverse Compton scattering of cosmic ray e with cosmic radiations. We compute the spin-averaged amplitudes squared of three processes and find that the advent of unparticle will never signi...

Iterative statistical X-ray CT reconstruction algorithms can improve image quality for low dose scans. Unfortunately, their clinical utility has been hampered by their enormous computational requirements; typical low-dose reconstructions require about an hour on commercial systems. Most existing parallel implementations use a shared memory programming model, limiting available parallelism. We i...

We present a system to compute Boolean combinations of sculptured solids The surface of each solid is represented as a collection of trimmed and untrimmed spline surfaces and a connectivity graph Based on algorithms for trapezoidation of polygons partitioning of polygons using polygonal chains surface intersection of high degree spline surfaces and ray shooting we compute the boundaries of the ...