Learn More
In x-ray tomography, the structure of a three-dimensional body is reconstructed from a collection of projection images of the body. Medical CT imaging does this using an extensive set of projections from all around the body. However, in many practical imaging situations only a small number of truncated projections are available from a limited angle of view.(More)
In X-ray tomography, the structure of a three dimensional body is reconstructed from a collection of projection images of the body. Medical CT imaging does this using an extensive set of projections from all around the body. However, in many practical imaging situations only a small number of truncated projections is available from a limited angle of view.(More)
Strong, exciting, and engaging sound is perceived in the best concert halls. Here, it is shown that wideband early reflections that preserve the temporal envelope of sound contribute to the clear and open acoustics with strong bass. Such reflections are fused with the direct sound due to the precedence effect. In contrast, reflections that distort the(More)
This thesis represents a method for reducing the geometry of complex room models to make it possible to model their acoustics in real-time. It is shown that reducing geometry can vastly decrease the modeling time. This conclusion is supported by the experimental results. The previous work on geometric model simplification is surveyed extensively. The(More)
Dental tomographic cone-beam x-ray imaging devices record truncated projections and reconstruct a region of interest (ROI) inside the head. Image reconstruction from the resulting local tomography data is an ill-posed inverse problem. A new Bayesian multiresolution method is proposed for local tomography reconstruction. The inverse problem is formulated in(More)
Synthesizing the room impulse response (RIR) of an arbitrary enclosure may be performed using a number of alternative acoustic modeling methods, each with their own particular advantages and limitations. This article is concerned with obtaining a hybrid RIR derived from both wave and geometric-acoustics based methods, optimized for use across different(More)
(max 300 words) The 3D model of Epidaurus is simulated with a hybrid room acoustics modelling method. The low frequencies up to 500 Hz are simulated with a 3D FDTD method to be able to predict the wave-based phenomena such as diffraction and interference. The high frequencies are predicted with a beam tracing method. The early part of the computed impulse(More)
Finite-difference time domain methods are commonly used for acoustics modeling of enclosed geometries. For large spaces and high frequencies, the computational requirements become prohibitive in practical use. Thus, geometric acoustics algorithms are used in those cases. The results of these two classes of algorithm can be combined to model the full(More)
  • 1