Data protection from malicious attacks and misuse has become a crucial issue. Various types of data, including images, videos, audio and text documents, have given cause for the development of different methods for their protection. Cryptography, digital signatures and steganography are the most well known technologies used to protect data. During the last decade, digital watermarking technology has also been utilized as an alternative to prevent media forgery and tampering or falsification to ensure both copyright and authentication. Much work has been done to protect images, videos and audio but only a few algorithms have been considered for text document protection with digital watermarking. However, our survey observed that available text watermarking algorithms are neither robust nor imperceptible and as such remain unsecured methods of protection. Hence, research to improve the performance of text watermarking algorithms is required. This paper reviews current watermarking algorithms for text documents and categorizes text watermarking methods based on the way the text was treated during the watermarking process. It also discusses merits and demerits of available methods as well as recent proposed methods for evaluating text watermarking systems and the need for further research on digital text watermarking.

Multimedia evolution in the current era has given digital images security and privacy a great concern. Digital image watermarking is used to produce highly protected images in order to promote secure and protected exchange over the network and between individuals. In this paper, a robust algorithm for digital image watermarking is proposed based on a hybrid watermarking and auto‐thresholding. This algorithm is designed to embed the watermarks in the transform domain using both discrete cosine transform and discrete wavelet transform (DCT‐DWT). Image is transformed to DCT then to DWT and the algorithm trains itself to choose the best embedding threshold. This threshold must satisfy a performance trade‐off and at the same time attains high imperceptibility and robustness. The algorithm performance is evaluated under various attacks and showed high‐performance level. Imperceptibility evaluation showed peak signal‐to‐noise ratio above 42.96 dB and similarity percentage above 99.27%. The algorithm proved high resistance to noising, scaling, cropping, rotation, and compression attacks. Copyright © 2015 John Wiley & Sons, Ltd.

Mobile operating systems should adapt to different applications requirement such as multimedia, games, video and audio applications, and mobile calls, etc. Process scheduling is considered as the most important part of the mobile operating system, which has the responsibility for adapting the operating systems to these applications requirements. In this work, the architecture for a runtime CPU scheduler customization framework for the Linux kernel that take into account different applications requirements is presented. The Runtime CPU Scheduler Customization (RCSC) framework permits the mobile devices users as well as the developers of Linux-based mobile operating systems to customize CPU scheduler to run with a specific scheduling policy as well as evaluate newly developed scheduling policies from user space at runtime. As a consequence, mobile operating system can be tuned manually or automatically in order to adapt with the requirements of a particular application.

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Abstract-Research in digital watermarking has evolved rapidly in the current decade. This evolution brought various different methods and algorithms for watermarking digital images and videos. Introduced methods in the field varies from weak to robust according to how tolerant the method is implemented to keep the existence of the watermark in the presence of attacks. Rotation attacks applied to the watermarked media is one of the serious attacks which many, if not most, algorithms cannot survive. In this paper, a new automatic rotation recovery algorithm is proposed. This algorithm can be plugged to any image or video watermarking algorithm extraction component. The main job for this method is to detect the geometrical distortion happens to the watermarked image/images sequence; recover the distorted scene to its original state in a blind and automatic way and then send it to be used by the extraction procedure. The work is limited to have a recovery process to zero padded rotations for now, cropped images after rotation is left as future work. The proposed algorithm is tested on top of extraction component. Both recovery accuracy and the extracted watermarks accuracy showed high performance level.