Abstract: A method and an apparatus for buffering and obtaining resources as well as a resource buffering system are disclosed. The method includes: obtaining an access popularity value of a resource from a database at intervals of a first preset time, and obtaining load values of cache servers from the database if determining that the access popularity value reaches a preset first threshold; and determining a duplication cache server for duplicating the resource according to the access popularity value and the load values, and notifying the duplication cache server to duplicate the resource from a cache server that stores the resource and buffer the resource. The method overcome the problems in the prior, namely, the same resource is buffered in only one cache server and the relatively idle cache servers are unable to share loads with busy cache servers. The method improves extensibility and working efficiency of the buffering system.

Abstract: Message-wise unequal error protection is provided using codeword flipping to separate special and ordinary codewords without discarding any codewords. Special messages are encoded to ensure the codeword weight is less than a certain threshold weight. Ordinary messages are encoded to ensure the codeword weight is greater than the threshold weight. The bits of the codeword are flipped to enforce the weight criterion. Ordinary and special messages are encoded using different encodings to provide different levels of error protection. Upon receipt, codewords are separated into special and ordinary codewords for appropriate decoding. If a codeword is of indeterminate type, it is iteratively processed as both a special codeword and an ordinary codeword. The decoding result of each process is periodically checked to determine which decoding result satisfies decoding criteria.

Abstract: A method for low-density parity-check hard decision decoding includes computing, for every decoding iteration, a discrepancy of extrinsic messages responsive to channel inputs of a receiver, performing a flipping of the channel inputs responsive to a comparison of the discrepancy of extrinsic messages to a flipping threshold, the flipping threshold for each decoding iteration being determined based on a threshold computation responsive to a channel error probability estimation in a first iteration of a decoding of the channel inputs, and check node decoding responsive to the flipping of channel inputs

Abstract: The present invention provides a method for preparation of 2?-deoxy-2?,2?-difluoro-?-cytidine or pharmaceutically acceptable salt thereof, comprising starting from 1,6-anhydro-?-D-glucose as raw material, oxidizing, and fluorinating to obtain 2-deoxy-2,2-difluoro-D-ribofuranose as intermediate. The 2?-deoxy-2?,2?-difluoro-?-cytidine was finally prepared from the intermediate of 2-deoxy-2,2-difluoro-D-ribofuranose. The method is simple in operation and has a high yield. The method can effectively be used in large-scale production.

Abstract: The present invention provides a method for preparation of 2?-deoxy-2?,2?-difluoro-?-cytidine or pharmaceutically acceptable salt thereof, comprising starting from 1,6-anhydro-?-D-glucose as raw material, oxidizing, and fluorinating to obtain 2-deoxy-2,2-difluoro-D-ribofuranose as intermediate. The 2?-deoxy-2?,2?-difluoro-?-cytidine was finally prepared from the intermediate of 2-deoxy-2,2-difluoro-D-ribofuranose. The method is simple in operation and has a high yield. The method can effectively be used in large-scale production.