Comitês de bacia hidrográfica do Estado do Rio de Janeiro: avanços e dificuldades na gestão das águas.

Uma nova Constituição Federal foi estabelecida no final dos anos 80 conferindo à sociedade civil o direito de participar ativamente nas tomadas de decisões em diversas áreas, como a de recursos hídricos, através de representações de segmentos sociais. No contexto da gestão participativa das águas, o Estado do Rio de Janeiro instituiu sua Política Estadual de Recursos Hídricos, pela Lei n 3.239 em 1999, e criou o Sistema Estadual de Gerenciamento de Recursos Hídricos. Dentro das diretrizes estabelecidas pela Lei das Águas, nove comitês fluminenses foram criados, de acordo com as divisões de bacias hidrográficas. Este trabalho propõe analisar os comitês de bacia, quanto ao desempenho de suas atribuições, através de uma pesquisa qualitativa junto aos membros titulares desses colegiados. Com metodologia baseada no conceituado Projeto Marca dÁgua, um extenso questionário foi aplicado utilizando-se de uma plataforma Survey via internet, onde no total coletou-se 112 respostas. Dos resultados, no geral, conclui-se que os Comitês fluminenses vivem um momento de progresso e que a gestão realizada vem demonstrando resultados satisfatórios.

Digital watermarking with complex wavelets

In this paper, we propose a watermarking algorithm in the complex wavelet domain. We then model watermarking as a communication process and show that the complex wavelet domain has relatively high capacity and is a potentially good domain for watermarking. Finally, a technique for registering geometrically distorted images, which is based on motion estimation in the wavelet domain, is described. The registration process can assist watermark detection in a watermarked image attacked by Stirmark, for example.

基于弱信号检测理论的离散小波变换域数字水印盲检测算法

水印检测是数字水印技术的一个关键步骤,但是目前所提出的绝大多数水印检测算法既不具备赖以支撑的理论基础,其检测性能也不是优化的.利用数字水印的不可感知特性,应用弱信号检测理论进行水印检测的研究.首先从图像小波变换系数的统计特性出发,利用广义高斯分布(GGD)来建立小波细节子带系数的统计分布模型;然后针对水印嵌入强度未知的情况,将水印检测问题转化为非高斯噪声中具有未知参数的确定性信号的检测,在弱信号条件下提出一种离散小波变换(DWT)域图像水印的优化盲检测算法.检测性能分析表明,该检测算法能够实现恒虚警率水印检测.实验结果验证了检测性能理论分析的有效性和实际性能的优越性.

DCT变换域乘嵌入图像水印的检测算法

目前大多数水印算法采用线性相关的方法检测水印，但是，当原始媒体信号不服从高斯分布，或者水印不是以加嵌入方式嵌入到待保护的媒体对象中时，该方法存在一定的问题．数字水印的不可感知性约束决定了水印检测是一个弱信号检测问题，利用这一特性，首先从图像DCT（discrete cosine transfom）交流变换系数的统计特性出发，应用广义高斯分布来建立其统计分布模型，然后将水印检测问题转化为二元假设检验问题，以非高斯噪声中弱信号检测的基本理论作为乘嵌入水印的理论检测模型，推导出优化的乘嵌入水印检测算法，并对检测算法进行了实验．结果表明，对于未知嵌入强度的乘水印的盲检测，提出的水印检测器具有良好的检测性能．因此，该检测器能在数字媒体数据的版权保护方面得到了实际的应用．

公开可验证的零知识水印检测

对称水印方案的水印检测密钥可以被用来伪造和移去水印，因此要求它在检测过程中也是保密的．零知识的水印检测方案利用密码学中零知识和知识证明的思想和算法，实现在水印检测时使得验证者确信水印存在性的同时又不泄漏水印检测密钥．提出了公开可验证的零知识水印检测的安全需求，给出一个公开可验证的承诺方案和一个证明知道被承诺值的离散对数的零知识知识证明协议．在此基础上提出了一个公开可验证的零知识水印方案，并讨论了它的安全性．

DCT域图像水印的局部优化检测性能研究

水印检测是数字水印技术最关键的步骤之一.水印检测的传统方法是采用线性相关的方法,但是该方法存在问题.本文根据数字图像离散余弦变换(DCT)域交流系数的广义高斯分布模型,对图像水印的局部优化检测方法进行了推导,并给出了水印检测器检测性能的理论分析结果.实验结果验证了图像水印局部优化检测方法检测性能理论分析的有效性,以及实际检测性能的优越性.

Local histogram based geometric invariant image watermarking

Compared with other existing methods, the feature point-based image watermarking schemes can resist to global geometric attacks and local geometric attacks, especially cropping and random bending attacks (RBAs), by binding watermark synchronization with salient image characteristics. However, the watermark detection rate remains low in the current feature point-based watermarking schemes. The main reason is that both of feature point extraction and watermark embedding are more or less related to the pixel position, which is seriously distorted by the interpolation error and the shift problem during geometric attacks. In view of these facts, this paper proposes a geometrically robust image watermarking scheme based on local histogram. Our scheme mainly consists of three components: (1) feature points extraction and local circular regions (LCRs) construction are conducted by using Harris-Laplace detector; (2) a mechanism of grapy theoretical clustering-based feature selection is used to choose a set of non-overlapped LCRs, then geometrically invariant LCRs are completely formed through dominant orientation normalization; and (3) the histogram and mean statistically independent of the pixel position are calculated over the selected LCRs and utilized to embed watermarks. Experimental results demonstrate that the proposed scheme can provide sufficient robustness against geometric attacks as well as common image processing operations. (C) 2010 Elsevier B.V. All rights reserved.

Local Feature Based Geometric-Resistant Image Information Hiding

Watermarking aims to hide particular information into some carrier but does not change the visual cognition of the carrier itself. Local features are good candidates to address the watermark synchronization error caused by geometric distortions and have attracted great attention for content-based image watermarking. This paper presents a novel feature point-based image watermarking scheme against geometric distortions. Scale invariant feature transform (SIFT) is first adopted to extract feature points and to generate a disk for each feature point that is invariant to translation and scaling. For each disk, orientation alignment is then performed to achieve rotation invariance. Finally, watermark is embedded in middle-frequency discrete Fourier transform (DFT) coefficients of each disk to improve the robustness against common image processing operations. Extensive experimental results and comparisons with some representative image watermarking methods confirm the excellent performance of the proposed method in robustness against various geometric distortions as well as common image processing operations.

The infuence of yeast rhomboid protease on the import of Tic40 into the yeast mitochondrion

Yeast rhomboid protease (Rbd1p) was found to act in the processing of Tic40 components in the yeast mitochondrion. Rhomboid protease was shown to have effects on the number of different Tic40 configurations displayed, the ratio of different configurations to one another and the targeting of Tic40 configurations within the yeast mitochondrion. The effects of Rbd1p on the ratio and targeting of different Tic40 configurations were also found to be dependent on the developmental stage of the yeast. Tic40 deletion constructs were expressed in yeast strains with active yeast rhomboid protease and in corresponding strains lacking Rbd1p. The processing of Tic40 differed between deletion constructs and between strains with and without yeast rhomboid protease. This indicates that rhomboid protease can affect the processing of Tic40 and the sequence of Tic40 can affect the activity of rhomboid protease with respect to Tic40. Tic40 is suspected to be involved in the regulation of plastid protein import. Rhomboid protease is shown here to affect the properties of Tic40 which have made it a candidate for a regulator of plastid protein import.

A Low Complexity Video Watermarking in H.264 Compressed Domain

In this paper, a new blind and readable H.264 compressed domain watermarking scheme is proposed in which the embedding/extracting is performed using the syntactic elements of the compressed bit stream. As a result, it is not necessary to fully decode a compressed video stream both in the embedding and extracting processes. The method also presents an inexpensive spatiotemporal analysis that selects the appropriate submacroblocks for embedding, increasing watermark robustness while reducing its impact on visual quality. Meanwhile, the proposed method prevents bit-rate increase and restricts it within an acceptable limit by selecting appropriate quantized residuals for watermark insertion. Regarding watermarking demands such as imperceptibility, bit-rate control, and appropriate level of security, a priority matrix is defined which can be adjusted based on the application requirements. The resulted flexibility expands the usability of the proposed method.

Watermarking for Multimedia Security using Complex Wavelets

This paper investigates the application of complex wavelet transforms to the field of digital data hiding. Complex wavelets offer improved directional selectivity and shift invariance over their discretely sampled counterparts allowing for better adaptation of watermark distortions to the host media. Two methods of deriving visual models for the watermarking system are adapted to the complex wavelet transforms and their performances are compared. To produce improved capacity a spread transform embedding algorithm is devised, this combines the robustness of spread spectrum methods with the high capacity of quantization based methods. Using established information theoretic methods, limits of watermark capacity are derived that demonstrate the superiority of complex wavelets over discretely sampled wavelets. Finally results for the algorithm against commonly used attacks demonstrate its robustness and the improved performance offered by complex wavelet transforms.

Perceptual Watermarking for Discrete Shearlet Transform

This paper presents a new perceptual watermarking model for Discrete Shearlet transform (DST). DST provides the optimal representation [10] of the image features based on multi-resolution and multi-directional analysis. This property can be exploited on for watermark embedding to achieve the watermarking imperceptibility by introducing the human visual system using Chou’s model. In this model, a spatial JND profile is adapted to fit the sub-band structure. The combination of DST and the Just-Noticeable Distortion (JND) profile improves the levels of robustness against certain attacks while minimizing the distortion; by assigning a visibility threshold of distortion to each DST sub-band coefficient in the case of grey scale image watermarking.

Efficient Watermarking Schemes for Speaker Verification Guaranteeing Non-repudiation

Presently different audio watermarking methods are available; most of them inclined towards copyright protection and copy protection. This is the key motive for the notion to develop a speaker verification scheme that guar- antees non-repudiation services and the thesis is its outcome. The research presented in this thesis scrutinizes the field of audio water- marking and the outcome is a speaker verification scheme that is proficient in addressing issues allied to non-repudiation to a great extent. This work aimed in developing novel audio watermarking schemes utilizing the fun- damental ideas of Fast-Fourier Transform (FFT) or Fast Walsh-Hadamard Transform (FWHT). The Mel-Frequency Cepstral Coefficients (MFCC) the best parametric representation of the acoustic signals along with few other key acoustic characteristics is employed in crafting of new schemes. The au- dio watermark created is entirely dependent to the acoustic features, hence named as FeatureMark and is crucial in this work. In any watermarking scheme, the quality of the extracted watermark de- pends exclusively on the pre-processing action and in this work framing and windowing techniques are involved. The theme non-repudiation provides immense significance in the audio watermarking schemes proposed in this work. Modification of the signal spectrum is achieved in a variety of ways by selecting appropriate FFT/FWHT coefficients and the watermarking schemes were evaluated for imperceptibility, robustness and capacity char- acteristics. The proposed schemes are unequivocally effective in terms of maintaining the sound quality, retrieving the embedded FeatureMark and in terms of the capacity to hold the mark bits. Robust nature of these marking schemes is achieved with the help of syn- chronization codes such as Barker Code with FFT based FeatureMarking scheme and Walsh Code with FWHT based FeatureMarking scheme. An- other important feature associated with this scheme is the employment of an encryption scheme towards the preparation of its FeatureMark that scrambles the signal features that helps to keep the signal features unreve- laed. A comparative study with the existing watermarking schemes and the ex- periments to evaluate imperceptibility, robustness and capacity tests guar- antee that the proposed schemes can be baselined as efficient audio water- marking schemes. The four new digital audio watermarking algorithms in terms of their performance are remarkable thereby opening more opportu- nities for further research.

Representaciones sociales de la medicina complementaria y alternativa (MCA) para el cáncer en estudiantes universitarios de carreras de ciencias de la salud

Se realizó un estudio cualitativo exploratorio con estudiantes de carreras de Ciencias de la Salud con el objetivo de comprender las representaciones sociales que tienen acerca de la Medicina Complementaria y Alternativa (MCA) para el cáncer. Se desarrollaron grupos focales y la información obtenida fue analizada a través del Análisis Temático e interpretada con base en la Teoría de las Representaciones Sociales. Se encontraron diversas representaciones sociales asociadas con la definición, los objetivos, los tratamientos, la eficacia, las fuentes de información y el origen de la MCA. En conclusión se evidenció una alta tendencia a la aceptación y a la manifestación de una actitud positiva, aunque ambivalente frente a la MCA, además de un desconocimiento por la diferenciación conceptual entre este tipo de Medicina y la Medicina Popular. La cultura y las creencias sociales predominan en las representaciones sociales que tienen los estudiantes de la MCA para el cáncer, pese a su formación académica.

Metas de logro, diversi??n y persistencia-esfuerzo en estudiantes de Educaci??n F??sica durante una unidad did??ctica sobre judo

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