2 resultados para SOFT-START POLYMERIZATION
em WestminsterResearch - UK
Resumo:
The provision of children's content should be a key constituent of the public service brand, but has often been viewed as a programme category at risk. Certainly in many countries children's television has moved from the 'scarcity' associated with terrestrial provision, to the 'plenty' of digital (see Ellis 2000). However in spite of a range of dedicated public service children's channels in Europe (CBeebies, Kika, Z@ppelin), domestically produced children's television in Europe is notoriously under-resourced if not marginalised. There is a pronounced reliance on imports (particularly on commercial television) notwithstanding the launch by US-owned multinationals (Disney, Nickelodeon, Cartoon Network) of localised versions of their children's television channels in many European countries. Within the broader context of global developments in children's media, this paper starts by outlining the recent and rapid crisis in British children's television and the factors that caused it. This was a crisis, which caught broadcasters and producers by surprise in the middle of 2006, but reflects many of the challenges faced by the children's television sector in other countries. It clearly demonstrated how a combination of the lack of regulatory protection, a change in commercial priorities among broadcasters, advertising restrictions, budgetary pressures and the competitive environment at home and abroad all combined to reinforce the trend towards a contraction of domestic production. The crisis also served to underline the dominance of the BBC - both as a representative of public service principles, and as the dominant producer and commissioner in the market. With the reasons underpinning the crisis explained, the paper will then analyse how the children's television community responded to the crisis and with what effect. Based on interviews, contemporary accounts and documentary evidence the paper will chart the converging and diverging views of broadcasters, producers, regulatory authority Ofcom, and a range of advocacy groups which represent children's interests and the industry. What arguments were elaborated in favour of protecting children's television as an integral part of the public service media brand? Can lessons be learned about how best to ensure the origination of children's media within a public service environment? Can developments in the UK be used to provide insight into how children's media might develop further?
Resumo:
Turbo codes experience a significant decoding delay because of the iterative nature of the decoding algorithms, the high number of metric computations and the complexity added by the (de)interleaver. The extrinsic information is exchanged sequentially between two Soft-Input Soft-Output (SISO) decoders. Instead of this sequential process, a received frame can be divided into smaller windows to be processed in parallel. In this paper, a novel parallel processing methodology is proposed based on the previous parallel decoding techniques. A novel Contention-Free (CF) interleaver is proposed as part of the decoding architecture which allows using extrinsic Log-Likelihood Ratios (LLRs) immediately as a-priori LLRs to start the second half of the iterative turbo decoding. The simulation case studies performed in this paper show that our parallel decoding method can provide %80 time saving compared to the standard decoding and %30 time saving compared to the previous parallel decoding methods at the expense of 0.3 dB Bit Error Rate (BER) performance degradation.