Non-blind digital watermarking with enhanced image embedding capacity using DMeyer wavelet decomposition,SVD, and DFT

Amongst the requirements of digital color image watermarking–capacity is the major component to be addressed effectively. To address the same we proposed a method for inserting a color image into another color image of same size using non-blind watermarking scheme. From this method we achieved reasonably good perceptual similarity by measuring acceptable peak signal to noise ratio (PSNR) and structural similarity (SSIM) index. The method uses DMeyer single level discrete wavelet transformation (DWT) to get approximation coefficients-where most of the image information is stored, discrete Fourier transformation (DFT) is used to get set of components which are sufficient to describe the whole image and singular value decomposition (SVD) to get reliable orthogonal matrix of computationally sustainable components of the transformed image. The method is robust against attacks like–rotation, cropping, JPEG compression and for noises–salt and pepper, gaussian, speckle.     

A speech content authentication algorithm based on a novel watermarking method

Some audio watermark schemes robust against desynchronization attacks are based on synchronization code embedded by quantifying signal energy, which have some shortcomings. Such as, (1) they do not verify the authenticity of watermarked signal detected. (2) They are vulnerable to substitution attack. To address the shortcomings and considering the background, a speech content authentication algorithm is proposed in this paper. Firstly, the original speech signal is framed, and each frame is cut into some segments. Secondly, samples of the segments are scrambled, and self-correlation of the scrambled signal is calculated. Lastly, watermark bit generated by frame number is embedded by quantifying the self-correlation. If watermarked signal is attacked, the attacked frames can be detected according to the frame number extracted. Theoretical analysis and experiments demonstrate that the scheme is robust against desynchronization attacks, improves the security, and has a good performance in ability of tampering location.     

The authorship dilemma: alphabetical or contribution?

Scientific communities have adopted different conventions for ordering authors on publications. Are these choices inconsequential, or do they have significant influence on individual authors, the quality of the projects completed, and research communities at large? What are the trade-offs of using one convention over another? In order to investigate these questions, we formulate a basic two-player game theoretic model, which already illustrates interesting phenomena that can occur in more realistic settings. We find that contribution-based ordering leads to a denser collaboration network and a greater number of publications, while alphabetical ordering can improve research quality. Contrary to the assumption that free riding is a weakness of the alphabetical ordering scheme, when there are only two authors, this phenomenon can occur under any contribution scheme, and the worst case occurs under contribution-based ordering. Finally, we show how authors working on multiple projects can cooperate to attain optimal research quality and eliminate free riding given either contribution scheme.     

新品导购笔记本电脑

LG M1●处理器:Intel Core Duo T2300(1.6GHz,2M二级缓存)●显卡:Intel GMA950●屏幕:15英寸液晶炫丽屏●内存:512MB DDR2●硬盘:80G●光驱:COMBO价格:12999元M1外壳采用宝石蓝,乳白色的机身在两层幽蓝的映衬下更显细腻,二者结合在一起则在商务气息之中增添了一份时尚韵味,M1机身使用了斜角设计,前后两面柔滑的斜边将显示器单元托起,顶盖也以同样圆润的曲线顺滑下来,在机器前端形成一个赏心悦目的线条组合。而这款产品还装备了指纹验证装置,在安全性方面能够给用户更安心的数据保护功能。明基S61●处理器:Intel Core Duo T2300…     

银行分销渠道整合的位置-产量模型研究

在新金融条件下,如何有效整合银行传统的分销渠道而使其在新的挑战面前不失昔日风采,这是金融理论界和实践界近年来一直在探讨的问题。本文从博弈论的角度,建立一个位置-产量博弈模型来探讨此问题,通过求解博弈模型的均衡解,得出的结论是,当银行产品替代性较大时,银行的分销渠道应尽量分散化;当银行产品具有互补性时。银行的分销渠道应尽量集中化;当银行产品没有替代性或互补性时,银行的分销渠道选择具有较大任意性。据此,分析了我国银行网点设置不合理的原因及提出了有效整合我国银行业分销渠道的两点建议。     

Synthesis,structural and optical properties of CdS nanoparticles with enhanced photocatalytic activities by photodegradation of organic dye molecules

CdS nanoparticles (NPs) were synthesized using co-precipitation method. X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were used to confirm the structures and morphologies of CdS NPs. X-ray diffraction data confirmed the crystal structure of the CdS NPs. Raman spectrum exhibited the Raman modes of LO and 2LO of CdS at 290 and 595 cm^?1 respectively. The evaluated band gap was 3.15 eV, this value was shifted compared with the bulk value and this could be a significance of a size quantization effect in the sample. The CdS nanoparticles showed higher photocatalytic activity for the discoloration of methyl orange (MO) under UV light irradiation for 90 min. The highest photocatalytic activity was obtained with the sample containing 0.3 wt % CdS nanoparticles, in which more than 98 % of the MO was discolored within 90 min.