Various index structures have recently been proposed to facilitate high-dimensional KNN queries, among which the techniques of approximate vector presentation and one-dimensional (1D) transformation can break the curs...Various index structures have recently been proposed to facilitate high-dimensional KNN queries, among which the techniques of approximate vector presentation and one-dimensional (1D) transformation can break the curse of dimensionality. Based on the two techniques above, a novel high-dimensional index is proposed, called Bit-code and Distance based index (BD). BD is based on a special partitioning strategy which is optimized for high-dimensional data. By the definitions of bit code and transformation function, a high-dimensional vector can be first approximately represented and then transformed into a 1D vector, the key managed by a B+-tree. A new KNN search algorithm is also proposed that exploits the bit code and distance to prune the search space more effectively. Results of extensive experiments using both synthetic and real data demonstrated that BD out- performs the existing index structures for KNN search in high-dimensional spaces.展开更多
纸使这个问题担心怎么购买再保险以便做保险公司和再保险公司“在期望的价值原则下面最少的 s 总数风险。当保险公司和再保险同伴采取任意的风险措施时，为再保险合同的 optimality 的足够的条件在可被考虑的合同的限制的班以内被给。...纸使这个问题担心怎么购买再保险以便做保险公司和再保险公司“在期望的价值原则下面最少的 s 总数风险。当保险公司和再保险同伴采取任意的风险措施时，为再保险合同的 optimality 的足够的条件在可被考虑的合同的限制的班以内被给。进一步，最佳的再保险的明确的形式下面收缩风险措施被给的几个专辑，和方法到也决定参数。展开更多
基金Project (No. [2005]555) supported by the Hi-Tech Research and De-velopment Program (863) of China
文摘Various index structures have recently been proposed to facilitate high-dimensional KNN queries, among which the techniques of approximate vector presentation and one-dimensional (1D) transformation can break the curse of dimensionality. Based on the two techniques above, a novel high-dimensional index is proposed, called Bit-code and Distance based index (BD). BD is based on a special partitioning strategy which is optimized for high-dimensional data. By the definitions of bit code and transformation function, a high-dimensional vector can be first approximately represented and then transformed into a 1D vector, the key managed by a B+-tree. A new KNN search algorithm is also proposed that exploits the bit code and distance to prune the search space more effectively. Results of extensive experiments using both synthetic and real data demonstrated that BD out- performs the existing index structures for KNN search in high-dimensional spaces.
文摘纸使这个问题担心怎么购买再保险以便做保险公司和再保险公司“在期望的价值原则下面最少的 s 总数风险。当保险公司和再保险同伴采取任意的风险措施时，为再保险合同的 optimality 的足够的条件在可被考虑的合同的限制的班以内被给。进一步，最佳的再保险的明确的形式下面收缩风险措施被给的几个专辑，和方法到也决定参数。
基金This work is supported in part by the National Natural Science Foundation of China （No. 60472062） and the Natural Science Foundation of Hubei Province （No. 2004ABA038）.
