In the field of neurobiology of language, neuroimaging studies are generally based on stimulation paradigms consisting of at least two different conditions. Designing those paradigms can be very time-consuming and this traditional approach is necessarily data-limited. In contrast, in computational and corpus linguistics, analyses are often based on large text corpora, which allow a vast variety of hypotheses to be tested by repeatedly re-evaluating the data set.Furthermore, text corpora also allow exploratory data analysis in order to generate new hypotheses. By drawing on the advantages of both fields, neuroimaging and computational corpus linguistics, we here present a unified approach combining continuous natural speech and MEG to generate a corpus of speech-evoked neuronal activity.
The availability of poly-capillary lenses opens up a wide variety of possibilities for the analysis of small sample areas because a large part of the tube radiation can captured and focused on the sample. Propagation in the glass capillaries is achieved by external total reflection on their internal surface. At first the intensity gain of the lenses and their spot size were the most interesting parameters. However, by using these lenses in commercial instruments, other parameters became more important for characterizing their performance for spectroscopic use, e.g. the energy dependence of the spot size and of the transmission efficiency and their influence to the tube spectrum. In this paper, the examination of various lenses from different manufacturers is described. It is shown that for the main parameters spot size and intensity gain, the differences are negligible. However, other parameters can be influenced by the change in geometric parameters of the lens such as the diameter of the single capillaries and bending radius of the lenses. These changes need high perfection in lens manufacturing. It seems that at present only one of the manufacturers is able to control the process in this way. However, there is also another requirement for the implementation of lenses for commercial instruments, namely the uniformity of the outer dimensions. Only in this case can these components be used without special adaptation in a routine instrument. This also requires the complete control of the manufacturing process. Because the use of poly-capillary lenses is in its early stages, it seems necessary to define more exactly the parameters that characterize the x-ray optical components. Only in this case will it be possible to define the performance of the optics with high precision and compare lenses from different manufacturers.
L-shell x-ray production and subshell ionization cross sections have been measured for 0.4 -1.8-MeV/amu carbon and nitrogen ions for selected heavy elements with 72 & Z~~90. The results yre compared with the predictions of the ECPSSR theory [perturbed-stationary-state (PSS) theory with energyloss (E), Coulomb deflection (C), and relativistic (R) corrections] describing both direct ionization and electron-capture processes and the semiclassical approximation (SCA} calculations for direct ionization.For both theories significant deviations are found for L2-subshell ionization in the low-energy range.The multiple ionization of outer shells was studied by comparing L x-ray intensity ratios measured for heavy ions and protons. The ionization probabilities of the N4 subshell at zero impact parameter was extracted from these data. Measured ionization probabilities are compared with the predictions of the SCA theory and the "geometrical model. " The inAuence of multiple ionization on the measured Lsubshell cross sections is discussed.
Pixel-based and motion vector-based global motion estimation (GME) techniques are evaluated in this paper with an automatic system for camera motion characterization. First, the GME techniques are compared with a frame-by-frame PNSR measurement using five video sequences. The best motion vector-based GME method is then evaluated together with a common and a simplified pixel-based GME technique for camera motion characterization. For this, selected unedited videos from the TRECVid 2005 BBC rushes corpus are used. We evaluate how the estimation accuracy of global motion parameters affects the results for camera motion characterization in terms of retrieval measures. The results for this characterization show that the simplified pixel-based GME technique obtains results that are comparable with the common pixel-based GME method, and outperforms significantly the results of an earlier proposed motion vector-based GME approach.
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