Building a new decentralized domain name system based on blockchain technology is helping to solve problems,such as load imbalance and over-dependence on the trust of the central node.However,in the existing blockchai...Building a new decentralized domain name system based on blockchain technology is helping to solve problems,such as load imbalance and over-dependence on the trust of the central node.However,in the existing blockchain storage system,the storage overhead is very high due to its fullreplication data storage mechanism.The total storage consumption for each block is up to O(n)with n nodes.Erasure code applied to blockchains can significantly reduce the storage overhead,but also greatly lower the read performance.In this study,we propose a novel coding scheme for blockchain storage,Combination Locality based Erasure Code for Permissioned blockchain storage(CLEC).CLEC uses erasure code,parity locality,and topology locality in blockchain storage,greatly reducing reading latency and repair time.In CLEC,the storage consumption per block can be reduced to O(1),and the repair penalty can also be lowered to O(1).Experiments in an open-source permissioned blockchain Tendermint show that CLEC has a maximum repair speed of 6 times and a read speed of nearly 1.7 times with storage overhead of only 1.17 times compared to the current work,a great improvement in reading performance and repair performance with slightly increased storage overhead via implementation.展开更多
The mechanical properties of 316L stainless steel repaired with Fe314 under different temperatures and humidities without inert gas protection were studied. Results indicated favorable compatibility between Fe314 and ...The mechanical properties of 316L stainless steel repaired with Fe314 under different temperatures and humidities without inert gas protection were studied. Results indicated favorable compatibility between Fe314 and 316L stainless steel. The average yield strength, tensile strength, and sectional contraction percentage were higher in repaired samples than in 316L stainless steel, whereas the elongation rate was slightly lower. The different conditions of humiture environment on the repair sample exerted minimal influence on tensile and yield strengths. The Fe314 cladding layer was mainly composed of equiaxed grains and mixed with randomly oriented columnar crystal and tiny pores or impurities in the tissue. Results indicated that the hardness value of Fe314 cladding layer under different humiture environments ranged within 419-451.1 HVo.2. The field humimre environment also showed minimal impact on the average hardness of Fe314 cladding layers. Furthermore, 316L stainless steel can be repaired through laser cladding by using Fe314 powder without inert gas protection under different temperatures and humidity environments.展开更多
基金This work is supported by The National Key Research and Development Program of China(2019YFB1804502).
文摘Building a new decentralized domain name system based on blockchain technology is helping to solve problems,such as load imbalance and over-dependence on the trust of the central node.However,in the existing blockchain storage system,the storage overhead is very high due to its fullreplication data storage mechanism.The total storage consumption for each block is up to O(n)with n nodes.Erasure code applied to blockchains can significantly reduce the storage overhead,but also greatly lower the read performance.In this study,we propose a novel coding scheme for blockchain storage,Combination Locality based Erasure Code for Permissioned blockchain storage(CLEC).CLEC uses erasure code,parity locality,and topology locality in blockchain storage,greatly reducing reading latency and repair time.In CLEC,the storage consumption per block can be reduced to O(1),and the repair penalty can also be lowered to O(1).Experiments in an open-source permissioned blockchain Tendermint show that CLEC has a maximum repair speed of 6 times and a read speed of nearly 1.7 times with storage overhead of only 1.17 times compared to the current work,a great improvement in reading performance and repair performance with slightly increased storage overhead via implementation.
文摘The mechanical properties of 316L stainless steel repaired with Fe314 under different temperatures and humidities without inert gas protection were studied. Results indicated favorable compatibility between Fe314 and 316L stainless steel. The average yield strength, tensile strength, and sectional contraction percentage were higher in repaired samples than in 316L stainless steel, whereas the elongation rate was slightly lower. The different conditions of humiture environment on the repair sample exerted minimal influence on tensile and yield strengths. The Fe314 cladding layer was mainly composed of equiaxed grains and mixed with randomly oriented columnar crystal and tiny pores or impurities in the tissue. Results indicated that the hardness value of Fe314 cladding layer under different humiture environments ranged within 419-451.1 HVo.2. The field humimre environment also showed minimal impact on the average hardness of Fe314 cladding layers. Furthermore, 316L stainless steel can be repaired through laser cladding by using Fe314 powder without inert gas protection under different temperatures and humidity environments.
