Multiple Description Coding of Discrete Ergodic Sources

We investigate the problem of Multiple Description (MD) coding of discrete ergodic processes. We introduce the notion of MD stationary coding, and characterize its relationship to the conventional block MD coding. In stationary coding, in addition to the two rate constraints normally considered in the MD problem, we consider another rate constraint which reflects the conditional entropy of the process generated by the third decoder given the reconstructions of the two other decoders. The relationship that we establish between stationary and block MD coding enables us to devise a universal algorithm for MD coding of discrete ergodic sources, based on simulated annealing ideas that were recently proven useful for the standard rate distortion problem.Comment: 6 pages, 3 figures, presented at 2009 Allerton Conference on Communication, Control and Computin

From compression to compressed sensing

Can compression algorithms be employed for recovering signals from their underdetermined set of linear measurements? Addressing this question is the first step towards applying compression algorithms for compressed sensing (CS). In this paper, we consider a family of compression algorithms $\mathcal{C}_r$, parametrized by rate $r$, for a compact class of signals \mathcal{Q} \subset \mathds{R}^n. The set of natural images and JPEG at different rates are examples of $\mathcal{Q}$ and $\mathcal{C}_r$, respectively. We establish a connection between the rate-distortion performance of $\mathcal{C}_r$, and the number of linear measurements required for successful recovery in CS. We then propose compressible signal pursuit (CSP) algorithm and prove that, with high probability, it accurately and robustly recovers signals from an underdetermined set of linear measurements. We also explore the performance of CSP in the recovery of infinite dimensional signals

On the Separation of Lossy Source-Network Coding and Channel Coding in Wireline Networks

This paper proves the separation between source-network coding and channel coding in networks of noisy, discrete, memoryless channels. We show that the set of achievable distortion matrices in delivering a family of dependent sources across such a network equals the set of achievable distortion matrices for delivering the same sources across a distinct network which is built by replacing each channel by a noiseless, point-to-point bit-pipe of the corresponding capacity. Thus a code that applies source-network coding across links that are made almost lossless through the application of independent channel coding across each link asymptotically achieves the optimal performance across the network as a whole.Comment: 5 pages, to appear in the proceedings of 2010 IEEE International Symposium on Information Theory (ISIT

Optical Companding

We introduce a new nonlinear analog optical computing concept that compresses the signal's dynamic range and realizes non-uniform quantization that reshapes and improves the signal-to-noise ratio in the digital domain

Enabling initiation of a lean management system in SMEs: a case study of a high performance plastics manufacturer

This paper investigates the challenges in developing a Lean Management System in a typical Small to Medium Size Enterprise (SME’s) in the UK. Through a series of pilot projects measured and implemented by action research this case study reflects on the changes in mind-set and behaviours that are required on the part of the researcher in order to implement a Lean Manufacturing System. The implementation and suggestions by the researcher to adopt the observational methods such as visual data management and Hoshin Kanri were part of the action research. The data gathered influenced management strategy and planning to incorporate lean practices in the organisation. The actions and results were achieved by the workforce commitment to ensure embedding and sustainability for the future. Benefits realised included a 21% increase in on time delivery performance and cross functional problem solving actions resulted in a lead time reduction of 8 to 4 weeks