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71.
很多公司的在线销售增长情况不理想,领导者在失望之余认为原因是在线客户的忠诚度不高,消费意愿也不强。殊不知,在线销售不如人意的真实原因并非如此,而是公司没能充分发掘客户最为看重的价值点——参与感。  相似文献   
72.
We derive the correct formulation of the Doppler problem in which the received signal is scaled in time by a scale factor dependent on the relative radial velocity of the transmitter and the receiver, normalized by the propagation speed in the transmission medium. For sine waves, the conventional Doppler model in which the received signal is translated in frequency is equivalent to the scale model. However, for signals with non zero bandwidth, the difference can be quite significant, as we demonstrate. We further demonstrate simple methods, based on the discrete Fourier transform (DFT) and phase differentiation of the scale CAF, by which delay and scale may be accurately estimated.  相似文献   
73.
Abstract— Large‐area amorphous‐silicon flat‐panel x‐ray imaging detectors were introduced commercially about 10 years ago and have seen a steady increase in both volume and number of applications since. The flat‐panel‐detector industry was made possible by manufacturing methods and equipment first developed for the display industry. Here, the different types of flat‐panel detectors are described, with focus on the scintillator‐based TFT/photodiode detector. The manufacturing process used for these detectors is explained and compared to that for displays. Detector operation is detailed, and the various medical and industrial applications are described. Finally, the performance metrics for these detectors and the impact of the performance requirements on detector design are discussed.  相似文献   
74.
The traditional modes of knowledge production and circulation in academia are (slowly but surely) shifting from the hierarchical, top-down systems of print to the distributed, bottom-up systems of the Web. It is in the context of these shifts and the rapid development of Web 2.0 tools and methods that we argue for a concomitant shift in the predominant practices of graduate education in rhetoric—particularly for students of digital rhetoric. In this article, we describe the development of a research network that combines the power of digital networking with the collaborative facilitation offered by communities of practice and consider how research networks can be grown and sustained as part of the graduate education of technorhetoricians.  相似文献   
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Computer integrated manufacturing uses computer technology to integrate a manufacturing system through a man-machine interface that fills the gap between manual operation and machine processes. It is clear that a computer vision-based man-machine interface makes a fully automated system possible. The basic challenge of a vision-based interface is how to extract information from digitized images and convert it to machine-friendly knowledge. To extract information, then, it often end up to the problem of shape decomposition. This paper proposes an new approach in decomposing compound shapes without prior knowledge of the scene. The proposed algorithm exploits the fact that planar shapes can be completely described by contour segments, and can be decomposed at their maximum concavity into simpler objects. To reduce spurious decomposition, the decomposed segments are merged into groups by analyzing and utilizing the merging hypotheses. The algorithm calculates the linking possibility by weighting the angular differentiation between two segments. The techniques are implemented and are applied to other partial shape matching problems for clustering purposes.  相似文献   
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