684 research outputs found

    SEER-MCache: A Prefetchable Memory Object Caching System for IoT Real-Time Data Processing

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    Memory object caching systems, such as Memcached and Redis, have been proved to be a simple and high-efficient middleware for improving the performance of Internet of Things (IoT) devices querying the database in cloud. However, its performance guarantee is built on the fact that the target data, queried by the IoT device, will be accessed many times and hit in the caching system. Therefore, when database system is handling the unrepeated IoT queries, it usually presents the suboptimal performance, which greatly impairs the efficiency of real-time data processing on IoT devices. To improve this issue, we propose Seer-MCache, the memory object caching system with a smart prefetching (read-ahead) function, to fill up the caching system with the desired data before the intensive IoT queries arriving. Seer-MCache includes a set of rules to launch the specific behaviors of read-head. These rules are able to be customized according to the workload characteristics and system load. We implement a prototype system in Redis (caching layer) and MySQL server (database system). Extensive experiments are conducted to verify the effectiveness of Seer-MCache, the results show that Seer-MCache can improve the performance of read-intensive workload up to 61% (39.5% in average). Meanwhile, the cost of the read-ahead behavior is moderate and controllable

    Explaining the rise of 'human rights' in analyses of Sino-African relations

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    Popular perceptions of China and its global role are often shaped by two words: 'made in'. Yet this vision of China that focuses primarily on Beijing as a coming economic superpower is relatively new, and it is not that long ago that two other words tended to dominate debates on and discourses of China: 'human rights'. To be sure, real interest in human rights in China was never the only issue in other states' relations with China, nor consistently pursued throughout the years (Nathan, 1994). Nor did human rights totally subsequently disappear from the political agenda.1 Nevertheless, the rhetorical importance of human rights - perhaps best epitomised by the narrow defeat of resolutions condemning Chinese policy in 1995 at the Human Rights Council in Geneva - stands in stark contrast to the relative silence thereafter as the bottom line of most states' relations with Beijing took on ever greater economic dimensions

    A Bound-Independent Pruning Technique to Speeding up Tree-Based Complete Search Algorithms for Distributed Constraint Optimization Problems

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    Complete search algorithms are important methods for solving Distributed Constraint Optimization Problems (DCOPs), which generally utilize bounds to prune the search space. However, obtaining high-quality lower bounds is quite expensive since it requires each agent to collect more information aside from its local knowledge, which would cause tremendous traffic overheads. Instead of bothering for bounds, we propose a Bound-Independent Pruning (BIP) technique for existing tree-based complete search algorithms, which can independently reduce the search space only by exploiting local knowledge. Specifically, BIP enables each agent to determine a subspace containing the optimal solution only from its local constraints along with running contexts, which can be further exploited by any search strategies. Furthermore, we present an acceptability testing mechanism to tailor existing tree-based complete search algorithms to search the remaining space returned by BIP when they hold inconsistent contexts. Finally, we prove the correctness of our technique and the experimental results show that BIP can significantly speed up state-of-the-art tree-based complete search algorithms on various standard benchmarks
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