Introduction: The different factors that affect the camera uniformity of Single Photon Emission Computed Tomography (SPECT) technique have been analyzed including peak shift (%) and window width of energy. The effect of peak shift and window width on SPECT image uniformity has been investigated using a point source to perform intrinsic flood images. Methods:</stro...

objective(s): the energy resolution of a cadmium-zinc-telluride (czt) solid-state semiconductor detector is about 5%, and is superior to the resolution of the conventional anger type detector which is 10%. also, the window width of the high-energy part and of the low-energy part of a photo peak window can be changed separately. in this study, we used a semiconductor detector and examined the ef...

Bees seem to use landmarks to segment familiar routes. They can associate, with a landmark, a memory that encodes the direction and distance of the path segment between that landmark and the next. The expression of the memory results in the performance of a local vector matching the distance and direction of the path segment. The memories of path segments appear to be 'chained' together, so tha...

This paper presents a qualitative-reasoning method for predicting the behavior of mechanisms characterized by continuous, time-varying parameters. The structure of a mechanism is described in terms of a set of parameters and the constraints that hold among them : essentially a 'qualitative differential equation'. The qualitative-behavior description consists of a discrete set of time-points, at...

It is well-known that route distance estimates are influenced by the structure of the route. In particular, the number of features along the route (e.g. landmarks) and the structuring of the route into stretches have been shown to influence distance estimates, usually increasing them (feature accumulation, route structuring). However, the two effects have not been related to one another yet. Wh...

This paper presents an original method for splitting overlapped cells in microscopical images, based on a template matching strategy. First, a single template cell is estimated using an Expectation Maximization algorithm applied to a collection of correctly segmented cells from the original image. Next, a process based on matching the template against the clumped shape and removing the matched ...

Within psychology, at least two research communities study spatial cognition. One community studies systematic errors in spatial memory and judgement, accounting for them as a consequence of and clue to normal perceptual and cognitive processing. The other community studies navigation in real space, isolating the contributions of various sensory cues and sensorimotor systems to successful navig...

In this paper a numerical method to compute principal component geodesics for Kendall’s planar shape spaces which are essentially complex projective spaces is presented. Underlying is the notion of principal component analysis based on geodesics for non-Euclidean manifolds as proposed in an earlier paper by Huckemann and Ziezold (2006). Currently, principal component analysis for shape spaces i...