In this paper, frequency selective surface (FSS) with relative zero-phase shift is realized and characterized. The FSS unit cell is designed by adding cross aperture to the cross loop slot at its center, and the four ...
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In this paper, we proposed a novel multiple watermarking scheme, in which a robust watermark and a semi fragile watermark were simultaneously embedded for the image authentication. On one hand, a robust watermark carr...
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In this paper, we proposed a novel multiple watermarking scheme, in which a robust watermark and a semi fragile watermark were simultaneously embedded for the image authentication. On one hand, a robust watermark carrying visual perception characteristics was embedded into the low -frequency band of wavelet for image authentication. On the other hand, a semi-fragile watermark containing a significant two value image was embedded into the Intermediate frequency of wavelet for tamper location. If image restoration was needed, we could also repair the image in some extent according to perception information carried by robust watermark. The experimental results show that our robust watermark algorithm was robust to the normal image operation (geometric transformation, wave filtering and compression with loss for example). And our semi-fragile watermark was only sensitive with malicious operation whose value was higher than the threshold value, in the same time it could make the tamper localization within the range of certain precision. In addition, Visual perceptual information was set as image authentication standard in our scheme, the experimental results proved that it was much better than previous ones whose standard was the variation of data bit of the image, and this advantage also assured our algorithm flexible application in practice.
With emerging trend in technology wireless networks allow user to travel from one location to another. Mobile Adhoc network (MANET) is one of the subareas of wireless network that dynamically form infrastructure less ...
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Labriform Mode is an important maneuvering locomotion mode which is largely applied to teleost fish. For the exploration of new maneuvering surface of underwater vehicles, study on bionic pectoral fin of Labriform Mod...
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A broadband sleeve antenna with very small ground has been presented based on impedance matching network and resistive load. The VSWR of the proposed antenna is less than 2 from 0.17GHz to 0.52GHz. The efficiency of t...
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Antenna lens can obviously eincrease the gain of the antenna by method of gathering. Also, metamaterial lens can achieve the gathering effect with aspheric surface. In this paper, a new type of metamaterial lens is de...
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In this paper, three types of EIT metamaterials are presented and numerically investigated. The type I metamaterial consists of the SR and the SRR, which are coupled with each other and assigned as the dark resonator ...
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In phased array at subarray level with monopulse technology, generally, analog weighting at element level are adopted for sidelobe suppression of patterns, while digital weighting at subarray level for adaptive proces...
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Adaptive digital beamforming(ADBF) at subarray level is one of crucial techniques for phased array radar. Generalized sidelobe canceller(GSLC) at subarray level is an effective solution in the presence of array imperf...
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An review on the development and extrodinary properties of left-handed materials is first *** on the current research, left-handed materials is applied to the microstrip antenna *** miniaturized antenna are designed b...
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