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Distribution by Scientific Domains

Business, Economics, Finance and Accounting	40%

Selected Abstracts

Hardware-Based Volumetric Knit-Wear

COMPUTER GRAPHICS FORUM, Issue 3 2002
Katja Daubert
We present a hardware-based, volumetric approach for rendering knit wear at very interactive rates. A single stitch is represented by a volumetric texture with each voxel storing the main direction of the strands of yarn inside it. We render the knit wear in layers using an approximation of the Banks model. Our hardware implementation allows specular and diffuse material properties to change from one voxel to the next. This enables us to represent yarn made up of different components or render garments with complicated color patterns. Furthermore, our approach can handle self-shadowing of the stitches, and can easily be adapted to also include view-independent scattering. The resulting shader lends itself naturally to mip-mapping, and requires no reordering of the base geometry, making it versatile and easy to use. Categories and Subject Descriptors (according to ACM CCS): I.3.3 [Computer Graphics]: Hardware Applications Volumetric Textures [source]

Effect of Angular Error on Tissue Doppler Velocities and Strain

ECHOCARDIOGRAPHY, Issue 7 2003
Camilla Storaa M.S.
One of the major criticisms of ultrasound Doppler is its angle dependency, that is its ability to measure velocity components directly to or from the transducer only. The present article aims to investigate the impact of this angular error in a clinical setting. Apical two- and four-chamber views were recorded in 43 individuals, and the myocardium was marked by hand in each image. We assume that the main direction of the myocardial velocities is longitudinal and correct for the angular error by backprojecting measured velocities onto the longitudinal direction drawn. Strain was calculated from both corrected and uncorrected velocities in 12 segments for each individual. The results indicate that the difference between strain values calculated from corrected and uncorrected velocities is insignificant in 5 segments and within a decimal range in 11 segments. The biggest difference between measured and corrected strain values was found in the apical segments. Strain is also found to be more robust against angular error than velocities because the difference between corrected and uncorrected values is smaller for strain. Considering that there are multiple sources of noise in ultrasound Doppler measurements, the authors conclude that the angular error has so little impact on longitudinal strain that correction for this error can safely be omitted. (ECHOCARDIOGRAPHY, Volume 20, October 2003) [source]

Regional variations in the outer retina of atherinomorpha (Beloniformes, Atheriniformes, Cyprinodontiformes: Teleostei): Photoreceptors, cone patterns, and cone densities

JOURNAL OF MORPHOLOGY, Issue 3 2003
Frank Reckel
Abstract The outer retinae of adults of 13 atherinomorph species, representing nine different families, were examined by both light and electron microscopy. The retinae were investigated with respect to photoreceptor types, cone densities, and cone patterns. All data were composed to eye maps. This procedure allows an interspecific comparison of the regional differences within the outer retina among these shallow-water fish. Furthermore, for a more detailed pattern analysis nitro-blue tetrazolium chloride- (NBT)-stainings in the retina of Melanotaenia maccullochi are presented. Apart from rods, eight morphologically different cone types could be identified: short, intermediate, and long single cones, double cones (equal and unequal), triple cones (triangular and linear), and in Ameca splendens one quadruple cone. Dimensions and occurrence of photoreceptors vary among the respective species and within the retinal regions. In the light-adapted state, the cones are arranged in highly ordered mosaics. Five different cone tessellation types were found: row patterns, twisted row patterns, square patterns, pentagonal patterns, and, exclusively in Belone belone, a hexagonal pattern. In Melanotaenia maccullochi the different spectral photoreceptor classes correspond well with the distribution of morphological photoreceptor classes within the mosaic. Double cone density maxima together with a highly ordered cone arrangement usually occur in the nasal and/or ventral to ventrotemporal retina. In most of the species that were examined these high-density regions are presumed to process visual stimuli from the assumed main directions of vision, which mainly depend on feeding behavior and predator pressure. Our findings are discussed with respect to the variable behavioral and visual ecology and phylogeny of the respective species. J. Morphol. 257:270,288, 2003. © 2003 Wiley-Liss, Inc. [source]

Big Windows and Little Windows: Implementation in the ,Congested State'

PUBLIC ADMINISTRATION, Issue 2 2004
Mark Exworthy
This paper argues for the need to re-assess models of policy implementation in the ,congested state'. This re-appraisal focuses on two main directions. The first involves locating implementation in the context of wider models of the policy process. We fuse three models, those of Kingdon, Wolman, and Challis et al., to form a new ,policy streams' approach. The second examines implementation in multi-level governance. In the UK and elsewhere, much of the focus of traditional implementation studies has been on the link between one central government department and a local agency. However, this vertical (central-local) dimension fails to give sufficient stress to the other horizontal dimensions of ,central-central' and ,local-local'. Paraphrasing Kingdon's terms, implementation models also need to incorporate the ,little windows' at local level as well as the ,big' windows at national level. Using evidence relating to the implementation of UK policy towards health inequalities, this paper argues successful implementation is more likely when the three policy streams are linked across the three dimensions. The model is thought to be applicable to other areas of the public sectors and complex issues facing all governments. [source]

Opening up the innovation process: the role of technology aggressiveness

R & D MANAGEMENT, Issue 1 2009
Ulrich Lichtenthaler
Besides acquiring external knowledge, many firms have begun to actively commercialize technology, for example, by means of out-licensing. This increase in inward and outward technology transactions reflects the new paradigm of open innovation. Most prior research into open innovation is limited to theoretical considerations and case studies, whereas other lines of research have focused either on external technology acquisition or exploitation. In an integrative view, we consider inward and outward technology transactions as the main directions of open innovation. Moreover, technology aggressiveness, which constitutes an important dimension of technology strategy, is identified as a major determinant of open innovation. Data from a survey of 154 industrial firms are used to test three hypotheses relating technology aggressiveness, external technology acquisition, and external technology exploitation. In addition, clusters of firms with homogeneous strategies regarding technology aggressiveness and open innovation are identified. [source]