佳木斯大学学报（自然科学版）
佳木斯大學學報（自然科學版）
가목사대학학보（자연과학판）
JOURNAL OF JIAMUSI UNIVERSITY (NATURAL SCIENCE EDITION)
2014年
5期
766-770
,共5页
不确定性数据%Top-k%E-score%PPE-score
不確定性數據%Top-k%E-score%PPE-score
불학정성수거%Top-k%E-score%PPE-score
uncertain data%Top-k query%E-score%PPE-score
E-Score查询算法返回元组期望最大的k个结果，常常不能适应更高级客户的查询需求，语义需要改进使得更加合理。本文把位置概率引入进E-score语义，定义了一个新的Top-k查询语义---带有位置概率的期望得分排序（ PPE-Score ），并基于位置概率对算法进行修枝剪枝形成相应算法。最后用实验验证新剪枝算法的有效性。
E-Score查詢算法返迴元組期望最大的k箇結果，常常不能適應更高級客戶的查詢需求，語義需要改進使得更加閤理。本文把位置概率引入進E-score語義，定義瞭一箇新的Top-k查詢語義---帶有位置概率的期望得分排序（ PPE-Score ），併基于位置概率對算法進行脩枝剪枝形成相應算法。最後用實驗驗證新剪枝算法的有效性。
E-Score사순산법반회원조기망최대적k개결과，상상불능괄응경고급객호적사순수구，어의수요개진사득경가합리。본문파위치개솔인입진E-score어의，정의료일개신적Top-k사순어의---대유위치개솔적기망득분배서（ PPE-Score ），병기우위치개솔대산법진행수지전지형성상응산법。최후용실험험증신전지산법적유효성。
The existed E-Score query algorithm is to return the k tuples with the largest expected values . It is often unable to meet the demand of customers , and its semantic is also unreasonable .In this paper , the po-sition probability was introduced into E -score, and a new semantic of Top -k query was redefined called PPE-Score .Then tuples of each locations were pruned based on the positional probabilities to make the algorithm better .Finally , it was verified using experiments .
