Abstract. The realism of VR visualisation is diminished when images look pixelated or forms are faceted instead of smooth. What constitutes acceptable visual quality by viewers? This paper presents the survey results of what is the acceptable visual quality of triangle complexity and texture resolution for full-size VR visualisation on a large screen and serves as a guide to create VR models mo...

We describe an eeective approach to object or feature detection in point patterns via noise modeling. This is based on use of a redundant or non-pyramidal wavelet transform. Noise modeling is based on a Poisson process. We illustrate this new method with a range of examples. We use the close relationship between image (pixelated) and point representations to achieve the result of a clustering m...

Touch, such as a caress, can be interpreted as very pleasant. The emotional valence assigned to touch is likely related to certain bottom-up factors, such as optimal activation of C-tactile (CT) afferents. It is however unclear if besides somatosensory input, contextual factors related to the own body also play a role in the perceived pleasantness of touch. To test this, we manipulated visual a...

BACKGROUND Image-based measurement of absorbed dose of Ra-223 dichloride may be useful in predicting therapeutic outcome in patients with castration-resistant prostate cancer (CRPC). In general, SPECT has been found to be more accurate than planar imaging in terms of lesion-based analysis. The aims of this study were to assess the feasibility and clinical usefulness of Ra-223 SPECT. The energy ...

Introduction: Accurate calculation of equal square field size is important in radiation therapy and A factor, in the Vadash formula must be determine by considering collimator exchange effect. Therefore, the purpose of this study was to determine the best A factor, for calculation of equal square field size in treatment planning   Materials and Methods: A new...

We find the conditions for optimal collimator location by the method of “Lagrange undetermined multipliers”. We give a ‘global’ explanation for the advantage of tune splitting on betatron collimation in terms of the envelope of all possible optimal collimator positions. We make analytic calculations of the maximum amplitude of surviving particles for elliptic and jaw-type collimators at a varie...

We present results of investigations of the clinical significance of variations in the value of the 4-mm-collimator output factor, OF(4/18). Changes in treatment volume, dose-volume histograms (DVHs), and isodose distributions were studied, by varying OF(4/18) up to 20%. The variations were performed on a sample of clinical patient treatment plans for which the 4 mm collimator was used. Althoug...

The angular deflection of a 28.5 GeV electron beam passing off-axis between the jaws of a collimator, generating a transverse wakefield, were measured in End Station A (ESA) at SLAC. In total, fifteen different configurations of collimator geometry and material were tested: some were chosen for compatibility with previous measurements while others served to study the effect of geometry and tape...