Enabling Complexity-Performance Trade-Offs for Successive Cancellation Decoding of Polar Codes

Polar codes are one of the most recent advancements in coding theory and they have attracted significant interest. While they are provably capacity achieving over various channels, they have seen limited practical applications. Unfortunately, the successive nature of successive cancellation based decoders hinders fine-grained adaptation of the decoding complexity to design constraints and operating conditions. In this paper, we propose a systematic method for enabling complexity-performance trade-offs by constructing polar codes based on an optimization problem which minimizes the complexity under a suitably defined mutual information based performance constraint. Moreover, a low-complexity greedy algorithm is proposed in order to solve the optimization problem efficiently for very large code lengths.

Design methodology to trade off power, output quality and error resiliency: Application to color interpolation filtering

Power dissipation and tolerance to process variations pose conflicting design requirements. Scaling of voltage is associated with larger variations, while Vdd upscaling or transistor up-sizing for process tolerance can be detrimental for power dissipation. However, for certain signal processing systems such as those used in color image processing, we noted that effective trade-offs can be achieved between Vdd scaling, process tolerance and "output quality". In this paper we demonstrate how these tradeoffs can be effectively utilized in the development of novel low-power variation tolerant architectures for color interpolation. The proposed architecture supports a graceful degradation in the PSNR (Peak Signal to Noise Ratio) under aggressive voltage scaling as well as extreme process variations in. sub-70nm technologies. This is achieved by exploiting the fact that some computations are more important and contribute more to the PSNR improvement compared to the others. The computations are mapped to the hardware in such a way that only the less important computations are affected by Vdd-scaling and process variations. Simulation results show that even at a scaled voltage of 60% of nominal Vdd value, our design provides reasonable image PSNR with 69% power savings.

Autonomous collective agreements as a regulatory device in European labour law:How to read Article 139 EC

This article discusses whether European social partners can derive the competence to autonomously devise European collective labour agreements from Article 139 EC (equals Article III-212 Constitution of Europe). Placing the question in the context of discussions of EU governance and private lawmaking in general, the author starts with a comparative overview of legal conceptions for collective labour agreements in Europe, focusing on three Member States' orders where their effects are not or only partly regulated by state legislation. Based on this comparison, she analyses Article 139(2) and offers a new interpretation of its provisions concerning autonomous implementation of European social partner agreements. She concludes that European social partners do have the competence to agree on a basic agreement stating the rules for European collective bargaining autonomously.

Employers, trade unions and concession bargaining in the Irish recession

The issue of concession bargaining between employers and unions during the Great Recession has received little attention in the research literature. This article presents a systematic analysis of the conduct of concession bargaining during the recession in Ireland in the context of three forms of concession bargaining identified in the international literature: integrative concession bargaining, distributive concession bargaining and ultra concession bargaining – each with different but overlapping sets of institutional foundations and implications for employers and trade unions. Drawing on focus groups of managers and union officials and a representative survey of employers, the article shows that distributive concession bargaining has been the predominant form in the Irish recession. This form of concession bargaining is likely to have few lasting direct effects on employer or union roles in collective bargaining but nevertheless appears to have significant indirect implications for the silent marginalization of unions in workplaces.