In order to avoid the redundant and inconsistent information in distributed data streams, a sampling method based on min-wise hash functions is designed and the practical semantics of the union of distributed data str...In order to avoid the redundant and inconsistent information in distributed data streams, a sampling method based on min-wise hash functions is designed and the practical semantics of the union of distributed data streams is defined. First, for each family of min-wise hash functions, the data with the minimum hash value are selected as local samples and the biased effect caused by frequent updates in a single data stream is filtered out. Secondly, for the same hash function, the sample with the minimum hash value is selected as the global sample and the local samples are combined at the center node to filter out the biased effect of duplicated updates. Finally, based on the obtained uniform samples, several aggregations on the defined semantics of the union of data streams are precisely estimated. The results of comparison tests on synthetic and real-life data streams demonstrate the effectiveness of this method.展开更多
The Great Gatsby has been one of the most discussed topics,researchers has explored it from various aspects.In the researches,Nick Carraway was mainly seen as a narrator,and the research are mostly focus on the shift ...The Great Gatsby has been one of the most discussed topics,researchers has explored it from various aspects.In the researches,Nick Carraway was mainly seen as a narrator,and the research are mostly focus on the shift of his narrative prospective.Few people noticed that he was totally fit into the definition of the " wise old man".This paper tries to put an eye on the archetype of the hero Nick Carraway,whose figure is thought as in the archetype of the " wise old man".展开更多
基金The National Natural Science Foundation of China(No60973023,60603040)the Natural Science Foundation of Southeast University(NoKJ2009362)
文摘In order to avoid the redundant and inconsistent information in distributed data streams, a sampling method based on min-wise hash functions is designed and the practical semantics of the union of distributed data streams is defined. First, for each family of min-wise hash functions, the data with the minimum hash value are selected as local samples and the biased effect caused by frequent updates in a single data stream is filtered out. Secondly, for the same hash function, the sample with the minimum hash value is selected as the global sample and the local samples are combined at the center node to filter out the biased effect of duplicated updates. Finally, based on the obtained uniform samples, several aggregations on the defined semantics of the union of data streams are precisely estimated. The results of comparison tests on synthetic and real-life data streams demonstrate the effectiveness of this method.
文摘The Great Gatsby has been one of the most discussed topics,researchers has explored it from various aspects.In the researches,Nick Carraway was mainly seen as a narrator,and the research are mostly focus on the shift of his narrative prospective.Few people noticed that he was totally fit into the definition of the " wise old man".This paper tries to put an eye on the archetype of the hero Nick Carraway,whose figure is thought as in the archetype of the " wise old man".
