introduction radiotherapy with small fields is used widely in newly developed techniques. additionally, dose calculation accuracy of treatment planning systems in small fields plays a crucial role in treatment outcome. in the present study, dose calculation accuracy of two commercial treatment planning systems was evaluated against monte carlo method. materials and methods siemens once or linea...

We describe a framework for multiscale image analysis in which line segments play a role analogous to the role played by points in wavelet analysis. The framework has five key components. The beamlet dictionary is a dyadicallyorganized collection of line segments, occupying a range of dyadic locations and scales, and occurring at a range of orientations. The beamlet transform of an image f(x, y...

A common way to solve intensity-modulated radiation therapy (IMRT) optimization problems is to use a beamlet-based approach. The approach is usually employed in a three-step manner: first a beamlet-weight optimization problem is solved, then the fluence profiles are converted into step-and-shoot segments, and finally postoptimization of the segment weights is performed. A drawback of beamlet-ba...

This paper presents a new method for computing the Feature-adapted Beamlet transforms [1] in a fast and accurate way. This transform can be used for detecting features running along lines or piecewise constant curves. The main contribution of this paper is to unify the Fast Slant Stack method, introduced in [2], with linear filtering technique in order to implement the Feature-adapted Beamlet t...

The context-driven target recognition requires the object-of-interest (OOI) to be first detected. We use the multiscale beamlet transform to detect airport runways as the OOI for detecting the aircraft. The up-to-down strategy in the beamlet graph structure is used for the connectivity and directional continuation of the edges, which are first detected in a coarse scale and are then refined at ...

SPIDER (Source for Production of Ions of Deuterium Extracted from a Rf plasma) is an ion source test bed designed to extract and accelerate a negative ion current up to 40 A and 100 kV whose first beam is expected by the end of 2016. Two main effects perturb beamlet optics during the acceleration stage: space charge repulsion and the deflection induced by the permanent magnets (called co-extrac...

Vehicle video key frame processing as an important part of intelligent transportation systems plays a significant role. Traditional vehicle video key frame extraction often has lots of noises, it can’t meet the requirements of the recognition and tracking. In this paper, a novel method which is combined independent component analysis with beamlet transform is proposed. Firstly, a random matrix ...

In order to overcome the high computational complexity of beamlet tree-structure algorithm, the paper proposes an improved algorithm and applies it to pavement crack detection, thereby; solving the problem of pavement crack detection which has the disadvantages of poor noise immunity and inaccurate test results. First, the pavement crack image is rectified by multiplicative factors to eliminate...

This talk will describe ongoing and planned fast ignition theoretical and experimental work using the Z-machine in concert with the upgraded Z-Beamlet/PW laser system. Z can produce x-ray powers of 100-250TW, x-ray energies 1-1.8MJ, and > 200eV radiation temperatures and thus represents an interesting platform for compressing large quantities of matter for use as fast ignition targets. Soon Z w...