Client cache is an important technology for the optimization of distributed and centralized storage systems. As a representative client cache system, the performance of CacheFiles is limited by transition faults. Furt...Client cache is an important technology for the optimization of distributed and centralized storage systems. As a representative client cache system, the performance of CacheFiles is limited by transition faults. Furthermore, CacheFiles just supports a simple LRU policy with a tightly-coupled design. To overcome these limitations, we propose to employ Stable Set Model （SSM） to improve CacheFiles and design an enhanced CacheFiles, SAC. SSM assumes that data access can be decomposed to access on some stable sets, in which elements are always repeatedly accessed or not accessed together. Using SSM methods can improve the cache management and reduce the effect of transition faults. We also adopt loosely- coupled methods to design prefetch and replacement policies. We implement our scheme on Linux 2.6.32 and measure the execution time of the scheme with various file I/O benchmarks. Experiments show that SAC can significantly improve I/O performance and reduce execution time up to 84%0, compared with the existing CacheFiles.展开更多
For any C;diffeomorphism on a smooth compact Riemannian manifold that admits an ergodic measure with positive entropy,a lower bound of the Hausdorff dimension for the local stable and unstable sets is given in terms o...For any C;diffeomorphism on a smooth compact Riemannian manifold that admits an ergodic measure with positive entropy,a lower bound of the Hausdorff dimension for the local stable and unstable sets is given in terms of the measure-theoretic entropy and the maximal Lyapunov exponent.The main line of our approach to this result is under the setting of topological dynamical systems,which is also applicable to infinite-dimensional C;dynamical systems.展开更多
X. Deng et al. proved Chvātal＇s conjecture on maximal stable sets and maximal cliques in graphs. G. Ding made a conjecture to generalize Chvátal＇s conjecture. The purpose of this paper is to prove this conject...X. Deng et al. proved Chvātal＇s conjecture on maximal stable sets and maximal cliques in graphs. G. Ding made a conjecture to generalize Chvátal＇s conjecture. The purpose of this paper is to prove this conjecture in planar graphs and the complement of planar graphs.展开更多
Agriculture is an important foundation of China’s socio-economic development. To secure the sound development of modern agriculture in the 21st century, the supply of fertilizers such as potassium is a key factor. Ow...Agriculture is an important foundation of China’s socio-economic development. To secure the sound development of modern agriculture in the 21st century, the supply of fertilizers such as potassium is a key factor. Owing to the limited arable land in China, a vital measure to feed the country’s increasing population is the augmentation of fertilizers so as to gain higher per unit area grain yields. At present, for a fairly long time to come, additional fertilizer resources will mainly come from nitrogen, phosphorus and potassium fertilizers. But there is a severe application disproportion between nitroge-展开更多
The present paper investigates the problem of incentive compatibility of voting mechanism and shows that the mechanism of approval voting is incentive-compatible,i.e. its mechanism gives voters incentive for voting si...The present paper investigates the problem of incentive compatibility of voting mechanism and shows that the mechanism of approval voting is incentive-compatible,i.e. its mechanism gives voters incentive for voting sincerely.展开更多
基金supported by the National Basic Research 973 Program of China under Grant No.2011CB302304the National HighTechnology Research and Development 863 Program of China under Grant Nos.2011AA01A102,2013AA013201 and 2013AA013205+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences under Grant No.XDA06010401the Chinese Academyof Sciences Key Deployment project under Grant No.KGZD-EW-103-5(7)
文摘Client cache is an important technology for the optimization of distributed and centralized storage systems. As a representative client cache system, the performance of CacheFiles is limited by transition faults. Furthermore, CacheFiles just supports a simple LRU policy with a tightly-coupled design. To overcome these limitations, we propose to employ Stable Set Model （SSM） to improve CacheFiles and design an enhanced CacheFiles, SAC. SSM assumes that data access can be decomposed to access on some stable sets, in which elements are always repeatedly accessed or not accessed together. Using SSM methods can improve the cache management and reduce the effect of transition faults. We also adopt loosely- coupled methods to design prefetch and replacement policies. We implement our scheme on Linux 2.6.32 and measure the execution time of the scheme with various file I/O benchmarks. Experiments show that SAC can significantly improve I/O performance and reduce execution time up to 84%0, compared with the existing CacheFiles.
基金supported by National Natural Science Foundation of China(Grant No.11701394)supported by National Natural Science Foundation of China(Grant Nos.11971455 and 11731003)supported by National Natural Science Foundation of China(Grant Nos.11671279 and 11541003)。
文摘For any C;diffeomorphism on a smooth compact Riemannian manifold that admits an ergodic measure with positive entropy,a lower bound of the Hausdorff dimension for the local stable and unstable sets is given in terms of the measure-theoretic entropy and the maximal Lyapunov exponent.The main line of our approach to this result is under the setting of topological dynamical systems,which is also applicable to infinite-dimensional C;dynamical systems.
基金Supported by the National Natural Science Foundation of China (No. 10671081)self-determined research funds of CCNU09Y01005 and CCNU09Y01018 from the colleges’ basic research and operation of MOE
文摘X. Deng et al. proved Chvātal＇s conjecture on maximal stable sets and maximal cliques in graphs. G. Ding made a conjecture to generalize Chvátal＇s conjecture. The purpose of this paper is to prove this conjecture in planar graphs and the complement of planar graphs.
文摘Agriculture is an important foundation of China’s socio-economic development. To secure the sound development of modern agriculture in the 21st century, the supply of fertilizers such as potassium is a key factor. Owing to the limited arable land in China, a vital measure to feed the country’s increasing population is the augmentation of fertilizers so as to gain higher per unit area grain yields. At present, for a fairly long time to come, additional fertilizer resources will mainly come from nitrogen, phosphorus and potassium fertilizers. But there is a severe application disproportion between nitroge-
文摘The present paper investigates the problem of incentive compatibility of voting mechanism and shows that the mechanism of approval voting is incentive-compatible,i.e. its mechanism gives voters incentive for voting sincerely.
