Cognitive radio has been claimed to be a hopeful solution to the existing conflicts between spectrum demand growth and spectrum underutilization. The basic underlying idea of cognitive radio is to allow unlicensed users to access in an opportunistic and non-interfering manner some licensed bands temporarily unoccupied by licensed users. The cognitive radio concept relies on two basic premises: the current spectrum underutilization, which has been demonstrated in some spectrum measurements campaigns, and the ability of unlicensed users to effectively detect and identify the presence of different licensed technologies in order not to cause harmful interference. In this context, this paper reports the joint work on these two areas that is currently being carried out in the framework of the FP7 Network of Excellence in Wireless COMmunications (NEWCOM++). Concretely, this paper presents spectrum occupancy measurements conducted in the frequency range from 75 MHz to 7075 MHz that demonstrate the low degree to which spectrum is currently used in an urban outdoor environment and also describes the blind standard recognition sensor concept, a sensor embedded in a cognitive radio equipment to enable the identification of many commercial wireless standards without the need to connect to any network. The joint research in both areas is a key step in promoting and validating the idea of dynamic spectrum usage. © 2009 IEEE

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The goal of this work is to assess global cardiac function in terms of ventricular volume from Multi-Slice Computed Tomography dynamic dataset. We propose an approach for the segmentation of the left ventricle and the measurement of the ventricular volume along the whole cardiac cycle. It is based on the segmentation of the left cavities using a fuzzy connectedness algorithm. The interactive placement of a 3D valvular plane is then used to cut through the segmented surface in order to extract the left ventricle. This method provides, with few interactions, the cardiac volume along the whole cardiac cycle and global parameters such as end-cardiac phases volumes and ejection fraction. Results have been compared to measures estimated during clinical routine with MSCT and MRI and have provided satisfying results. The specificity and the sensibility of the method have also been measured by a comparison with a manual segmentation of reference, leading to a very good specificity of the proposed approach.

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