A family of array codes with a maximum distance separable(MDS) property, named L codes, is proposed. The greatest strength of L codes is that the number of rows(columns) in a disk array does not be restricted by t...A family of array codes with a maximum distance separable(MDS) property, named L codes, is proposed. The greatest strength of L codes is that the number of rows(columns) in a disk array does not be restricted by the prime number, and more disks can be dynamically appended in a running storage system. L codes can tolerate at least two disk erasures and some sector loss simultaneously, and can tolerate multiple disk erasures(greater than or equal to three) under a certain condition. Because only XOR operations are needed in the process of encoding and decoding, L codes have very high computing efficiency which is roughly equivalent to X codes. Analysis shows that L codes are particularly suitable for large-scale storage systems.展开更多
The basic conditions of Urban rail transit line test operation are mainly based on Basic condition for trial operation of urban rail transit (GB/T30013-2013) the basic conditions of the relevant provisions, but the ...The basic conditions of Urban rail transit line test operation are mainly based on Basic condition for trial operation of urban rail transit (GB/T30013-2013) the basic conditions of the relevant provisions, but the status and standard of trial operation of the basic conditions for assessment of the operating departments are still inadequate, during the three mouth of trial running operations, the specific work of trial operation and exercise are not clear about what this study focuses. This study emphasizes on the methods of operation assessment, through the Analysis Hierarchy Process (AHP) to make the commissioning work carry out smoothly and effectively, making the running exercise Rally, and the emergency and safety follow-up operation process can be quickly handled properly, and it is also helpful to the sustainable development of urban raft transit.展开更多
基金supported by the National Natural Science Foundation of China under Grant No.61202250
文摘A family of array codes with a maximum distance separable(MDS) property, named L codes, is proposed. The greatest strength of L codes is that the number of rows(columns) in a disk array does not be restricted by the prime number, and more disks can be dynamically appended in a running storage system. L codes can tolerate at least two disk erasures and some sector loss simultaneously, and can tolerate multiple disk erasures(greater than or equal to three) under a certain condition. Because only XOR operations are needed in the process of encoding and decoding, L codes have very high computing efficiency which is roughly equivalent to X codes. Analysis shows that L codes are particularly suitable for large-scale storage systems.
文摘The basic conditions of Urban rail transit line test operation are mainly based on Basic condition for trial operation of urban rail transit (GB/T30013-2013) the basic conditions of the relevant provisions, but the status and standard of trial operation of the basic conditions for assessment of the operating departments are still inadequate, during the three mouth of trial running operations, the specific work of trial operation and exercise are not clear about what this study focuses. This study emphasizes on the methods of operation assessment, through the Analysis Hierarchy Process (AHP) to make the commissioning work carry out smoothly and effectively, making the running exercise Rally, and the emergency and safety follow-up operation process can be quickly handled properly, and it is also helpful to the sustainable development of urban raft transit.