MOBILITY 2015 Tutorials

The Fifth International Conference on Mobile Services, Resources, and Users

MOBILITY 2015

June 21 - 26, 2015 - Brussels, Belgium

Tutorials

T1. An Introduction to the Hard Disk Drive (HDD), Modelling, Detection and Decoding for the Magnetic Recording Channel
Dr. Kheong Chan, Data Storage Institute (DSI), A*STAR (Agency for Science Technology and Research), Singapore

T2. High End Requirements and Practice: Advances in Sciences and Computing
Prof. Dr. Claus-Peter Rückemann, Leibniz Universität Hannover and Westfälische Wilhelms-Universität (WWU) Münster and North-German Supercomputing Alliance (HLRN), Germany

T3. Introduction to Information Hiding in Audio Signals for with an Extension to Image Steganography
Prof. Dr. Kaliappan Gopalan, Purdue University Calumet – Hammond, USA

DETAILS

Today's hard-disk drives (HDDs) are complex systems that encompass the mechanical, electrical, magnetic and materials engineering disciplines. They also contain a recording channel very similar to that in a standard baseband communications system.

This tutorial will give an overview of the technologies contributing to today's HDD's and subsequently focus on the recording channel that encodes and then retrieves the data that is written onto the HDD medium. The recording channel as a component of the HDD system, can itself can be broken down into several subcomponents consisting of encoding, the writing and readback processes which is reproduced in simulation via channel modelling, equalization, detection and decoding blocks.

The tutorial will touch on all the components of the read/write channel in the hard disk drive.

This tutorial focuses on the requirements and implementations of High End Computing resources resulting from many disciplines and sciences. Sustainable means of processing and computing are becoming increasingly important for many disciplines, not only for disciplines, which are spanning long time intervals like geosciences, environmental sciences, and archaeology. Illuminating the challenges and processes of computation and implementation also raises questions on the benefits and what the long-term sustainable knowledge and results are when working with advanced and complex application scenarios and what the relative significance of the content is.

The tutorial shows and discusses real examples of advanced implementations worldwide, introduces in architectures and operation, and tries to discuss consequences and solutions.

Some focus questions are:
- What are the High End Computing and storage requirements?
- How are solutions for requirements implemented in practice?
- What High End Computing system implementations exist in practice?
- Where/what are the emerging challenges?
- What are major demands / motivations / goals from disciplines?
- Are there sustainable data-centric and knowledge-centric long-term approaches?

It is intended to have a dialogue with the audience on how terms like "long-term", "computing", "knowledge", and "content" may be defined. This tutorial is addressed to all interested users, disciplines, geosciences, social, and life sciences, as well as to users of advanced applications and providers of resources and services for High End Computing. There are no special informatics prerequisites or High End Computing experiences necessary to take part in this tutorial.

T3. Introduction to Information Hiding in Audio Signals for with an Extension to Image Steganography
Prof. Dr. Kaliappan Gopalan, Purdue University Calumet – Hammond, USA

Information hiding and steganography are concerned with embedding information in a media (cover) signal in an imperceptible manner. Applications of steganography include watermarking for copyright protection and authentication, data hiding for secure storage and transmission, and covert communication using unclassified channels. Indiscernible hiding of information in an audio signal is more challenging than invisible modification of an image or video signal due to the wide dynamic range of human audibility in frequency and power level. In spite of this challenge, human auditory system imperfections, which lead to psychoacoustic masking effects in hearing and perception, can be exploited for unnoticeable modifying of a cover audio signal in accordance with a given piece of covert information. Since the modification is carried out in the masked regions of perceptibility, the information-embedded audio (stego) signal appears to be the same as the original signal in spectrogram and perceptual quality. Successful embedding depends, among others, on the discernibility of any difference between the original cover signal and the stego signal, robustness of the hidden information to noise, and recovery key that does not require the original cover audio signal.

This presentation will provide an overview of psychoacoustic masking-based audio steganography with an emphasis on the newly developed tone insertion techniques in the spectral and cepstral domains, and their extension to image embedding. Robustness of hidden data to noise and attacks, and quantitative measures for perceptual difference will also be discussed.

A related waveform-domain steganography that indirectly relies on auditory masking property will be presented with its extension to hiding data on images.

Background knowledge expected of the participants: Basic understanding of spectral domain representation of signals, DFT and IDFT.

Objectives: The objectives of the tutorial are to provide the audience an overview of multimedia embedding of information and leave them with an understanding of the basics of key-based audio signal modification for imperceptible and robust hiding of data with oblivious recovery.