Concrete is one of the most consumable construction materials on the earth.The concrete constitutes cement,sand,gravel,water and/or additives in definite proportions.The proportions of raw materials of concrete are de...Concrete is one of the most consumable construction materials on the earth.The concrete constitutes cement,sand,gravel,water and/or additives in definite proportions.The proportions of raw materials of concrete are decided by the concrete mix design.The mix design depends on the various factors.For mix design,most of the countries have their own specifications.In the present study,standard guidelines of India,Britain and America for the concrete mix design have been discussed.The concrete grades of M25,M35 and M45 were designed and compared.Indian Standards were also compared.It was concluded that a new revised version of Indian Standard code has the lowest value of water/cement ratio and highest quantity of cement as compared to other standards.展开更多
Based on the Berlekamp-Massy （BM） algorithm for Reed-Solomon（RS） decoding, an improved version is proposed, which focuses on how to find the error locator polynomial using least iterative operations. The condition...Based on the Berlekamp-Massy （BM） algorithm for Reed-Solomon（RS） decoding, an improved version is proposed, which focuses on how to find the error locator polynomial using least iterative operations. The conditions to end the iterative operations is derived. As a special case, criterion of only one error symbol in one received codeword is derived as well. Steps are listed concerning the implementation of the improved iterative decoding algorithm, which is carried out as software on the platform of TI＇s C6416 DSP. Decoding performance and decoding-delay of both improved and original algorithms under different （n,k） conditions are simulated. The results of simulations demonstrate that the improved algorithm has less computational complexity when the number of errors in a received codeword is relatively small. Therefore, in channels with low noise power spectrum density, the improved algorithm results in less decoding-delay than BM algorithm.展开更多
文摘Concrete is one of the most consumable construction materials on the earth.The concrete constitutes cement,sand,gravel,water and/or additives in definite proportions.The proportions of raw materials of concrete are decided by the concrete mix design.The mix design depends on the various factors.For mix design,most of the countries have their own specifications.In the present study,standard guidelines of India,Britain and America for the concrete mix design have been discussed.The concrete grades of M25,M35 and M45 were designed and compared.Indian Standards were also compared.It was concluded that a new revised version of Indian Standard code has the lowest value of water/cement ratio and highest quantity of cement as compared to other standards.
基金Sponsored by the National High Technology Research and Development Program of China ("863"Program) (2007AA01Z293)
文摘Based on the Berlekamp-Massy （BM） algorithm for Reed-Solomon（RS） decoding, an improved version is proposed, which focuses on how to find the error locator polynomial using least iterative operations. The conditions to end the iterative operations is derived. As a special case, criterion of only one error symbol in one received codeword is derived as well. Steps are listed concerning the implementation of the improved iterative decoding algorithm, which is carried out as software on the platform of TI＇s C6416 DSP. Decoding performance and decoding-delay of both improved and original algorithms under different （n,k） conditions are simulated. The results of simulations demonstrate that the improved algorithm has less computational complexity when the number of errors in a received codeword is relatively small. Therefore, in channels with low noise power spectrum density, the improved algorithm results in less decoding-delay than BM algorithm.
