4,660 research outputs found
Localized image watermarking based on feature points of scale-space representation
No full textThis paper proposes a novel method for content-based watermarking based on feature points of an image. At each feature point, the watermark is embedded after scale normalization according to the local characteristic scale. Characteristic scale is the maximum scale of the scale-space representation of an image at the feature point. By binding watermarking with the local characteristics of an image, resilience against affine transformations can be obtained easily. Experimental results show that the proposed method is robust against various image processing steps including affine transformations, cropping, filtering and JPEG compression. (C) 2004 Pattern Recognition Society. Published by Elsevier Ltd. All rights reserved
Comparative economic analysis between direct and indirect wiring in the copper-based local loop
No full textIn a copper-based local loop, a circuit pair is indirectly connected to each subscriber usually via a primary cross connection point (PCP) which acts as a buffer to absorb circuit demand fluctuations among subareas. But some telephone operators adhere to the classic practice of direct wiring based on technological preferences without taking advantage of cost-efficient flexibility points. We analyse the extra cost of maintaining the old: practice of direct wiring over the popular one using flexibility points in a single PCP area. For that, the expectation of circuit shortages in subareas during a single replenishment period for the direct wiring is first obtained. Exploiting the convexity of the expectation, we then present a procedure for optimally allocating circuits among subareas, which not only sen es its own purpose of circuit provisioning for the direct wiring but also precisely calculates the extra cost over the indirect case
Speech Enhancement Based on the Generalized Dual Excitation Model with Adaptive Analysis Window
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Numerical seismic response of single-degree-of-freedom structure supported by shallow foundation
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Ordering-disordering phenomena and micro-hardness characteristics of B2 phase in Fe-(5-6.5%)Si alloys
No full textThe disappearing and forming behavior of B2 ordered phase in high Si steels with Si-levels between 5 and 6.5% (by weight, unless specified otherwise) was investigated by observing TEM and measuring electrical resistivity and micro- and nano-hardness. The critical cooling rate for suppressing the formation of 132 ordered phase increased exponentially with Si-content. The ordered phase coarsening was observed to occur actively above 800 degrees C, where atoms have enough mobility. The removal of solidification segregation is necessary in order to reduce the amount of B2 ordered phase in the as-cast or hot-rolled state, to lower the annealing temperature for the dissolution of B2 ordered phase, and to shorten the annealing time. Micro-Vickers hardness depended only on Si-content even under various heat treatment conditions, and the nano-hardness had a small difference between B2 and A2 phases. In the high Si steels, the short-range order in A2 disordered phase was likely to cause a comparable hardness as that of B2 ordered phase. (c) 2005 Elsevier B.V. All rights reserved
The effect of heat treatments and Si contents on B2 ordering reaction in high-silicon steels
No full textThe silicon content was increased up to 6.5% (by weight, unless specified otherwise) to reduce the power loss of the silicon steels. These steels were prepared by the conventional casting method or by spray forming and were investigated with the aid of light optical microscopy (LOM) and transmission electron microscopy (TEM). The difference in the casting method did not result in any difference in suppressing the B2 ordering. The D0(3) phase was observed only in the as-cast 6.5%Si steel. It was almost impossible to suppress the B2 ordered phase keeping the silicon level as high as 6.5% even after the heat treatment at 1000 degreesC for 24 h or after hot rolling. It was necessary to change the Si level and control the cooling rate to suppress the ordering reaction, especially, in cooling after heat treatment. The silicon level of 5.87% was observed to be a critical value in suppressing the B? ordering reaction. (C) 2001 Elsevier Science B.V. All rights reserved.This study has been supported in the framework of the international joint research between Korea and USA by the Ministry of Science and Technology. Additional support from the BK21 Project is also appreciated
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