通过在U-tree中添加时间戳和速度矢量等时空因素,提出一种基于U-tree的高效率当前及未来不确定位置信息检索的索引结构TPU-tree,可以支持多维空间中不确定移动对象的索引,并提出了一种改进的基于p-bound的MP_BBRQ(modifiedp-bound based...通过在U-tree中添加时间戳和速度矢量等时空因素,提出一种基于U-tree的高效率当前及未来不确定位置信息检索的索引结构TPU-tree,可以支持多维空间中不确定移动对象的索引,并提出了一种改进的基于p-bound的MP_BBRQ(modifiedp-bound based range query)域查询处理算法,能够引入搜索区域进行预裁剪以减少查询精炼阶段所需代价偏高的积分计算.实验仿真表明,采用MP_BBRQ算法的TPU-tree概率查询性能极大地优于传统的TPR-tree索引,且更新性能与传统索引大致相当,具有良好的实用价值.展开更多
In this paper, it is supposed that the B&B algorithm finds the first optimal solution after h nodes have been expanded and m active nodes have been created in the state-space tree. Then the lower bound Ω(m+h log ...In this paper, it is supposed that the B&B algorithm finds the first optimal solution after h nodes have been expanded and m active nodes have been created in the state-space tree. Then the lower bound Ω(m+h log h) of the running time for the general sequential B&B algorithm and the lower bound Ω(m/p+h log p) for the general parallel best-first B&B algorithm in PRAM-CREW are proposed, where p is the number of processors available. Moreover, the lower bound Ω(M/p+H+(H/p) log (H/p)) is presented for the parallel algorithms on distributed memory system, where M and H represent total number of the active nodes and that of the expanded nodes processed by p processors, respectively. In addition, a nearly fastest general parallel best-first B&B algorithm is put forward. The parallel algorithm is the fastest one as p = max{hε, r}, where ε = 1/ rootlogh, and r is the largest branch number of the nodes in the state-space tree.展开更多
This paper presents a distributed game tree search algorithm called DDS. Based on communication overhead, st,orage requirement, speed up, and oiller factors, the performance of algorithm DDS* is analysed, and the numb...This paper presents a distributed game tree search algorithm called DDS. Based on communication overhead, st,orage requirement, speed up, and oiller factors, the performance of algorithm DDS* is analysed, and the number of nodes searched with SSS as well as a-b algorithm. The simulation test shows that. DDS* is an efficient and practical search algorithm.展开更多
Given a graph G, a subgraph C is called a clique of G if C is a complete subgraph of G maximal under inclusion and ｜C｜ ≥2. A clique-transversal set S of G is a set of vertices of G such that S meets all cliques of ...Given a graph G, a subgraph C is called a clique of G if C is a complete subgraph of G maximal under inclusion and ｜C｜ ≥2. A clique-transversal set S of G is a set of vertices of G such that S meets all cliques of G. The clique-transversal number, denoted as τC（G）, is the minimum cardinality of a clique-transversal set in G. The clique-graph of G, denoted as K（G）, is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques in G have nonempty intersection. Let F be a class of graphs G such that F = {G｜ K（G） is a tree}. In this paper the graphs in F having independent clique-transversal sets are shown and thus τC（G）/｜G｜ ≤ 1/2 for all G ∈F.展开更多
In this paper,we study the strong law of large numbers and Shannon-McMillan(S-M)theorem for Markov chains indexed by an infinite tree with uniformly bounded degree.The results generalize the analogous results on a hom...In this paper,we study the strong law of large numbers and Shannon-McMillan(S-M)theorem for Markov chains indexed by an infinite tree with uniformly bounded degree.The results generalize the analogous results on a homogeneous tree.展开更多
Let G be a graph on n vertices with bounded treewidth.We use fk(G)to denote the number of spanning forests of G with k components.Given a tree decomposition of width at most p of G,we present an algorithm to compute f...Let G be a graph on n vertices with bounded treewidth.We use fk(G)to denote the number of spanning forests of G with k components.Given a tree decomposition of width at most p of G,we present an algorithm to compute fk(G)for k=1,2,…,n.The running time of our algorithm is O((B(p+1))^(3)pn^(3)),where B(p+1)is the(p+1)-th Bell number.展开更多
描述一个网络舆情监控系统IPSMS(Internet public sentiment monitoring system)。该系统试图将网络新闻及论坛、BBS上的帖子依关键词搜索,并依"事件"聚类,让管理者通过阅读事件可以了解正在发生或已经发生的事件,并提供自动...描述一个网络舆情监控系统IPSMS(Internet public sentiment monitoring system)。该系统试图将网络新闻及论坛、BBS上的帖子依关键词搜索,并依"事件"聚类,让管理者通过阅读事件可以了解正在发生或已经发生的事件,并提供自动持续追踪事件发展的功能,以协助管理者快速完整且全面地了解事件全貌。系统由网页抓取器、网页解析器及跟踪检测系统三部分组成。由于网络舆情的特点是数据量巨大,为了提高效率,系统采用了网页清理技术,并且在话题跟踪过程中使用了k-d tree方法。最后,对系统的未来工作进行了展望。展开更多
文摘通过在U-tree中添加时间戳和速度矢量等时空因素,提出一种基于U-tree的高效率当前及未来不确定位置信息检索的索引结构TPU-tree,可以支持多维空间中不确定移动对象的索引,并提出了一种改进的基于p-bound的MP_BBRQ(modifiedp-bound based range query)域查询处理算法,能够引入搜索区域进行预裁剪以减少查询精炼阶段所需代价偏高的积分计算.实验仿真表明,采用MP_BBRQ算法的TPU-tree概率查询性能极大地优于传统的TPR-tree索引,且更新性能与传统索引大致相当,具有良好的实用价值.
基金This paper was supported by Ph. D. Foundation of State Education Commission of China.
文摘In this paper, it is supposed that the B&B algorithm finds the first optimal solution after h nodes have been expanded and m active nodes have been created in the state-space tree. Then the lower bound Ω(m+h log h) of the running time for the general sequential B&B algorithm and the lower bound Ω(m/p+h log p) for the general parallel best-first B&B algorithm in PRAM-CREW are proposed, where p is the number of processors available. Moreover, the lower bound Ω(M/p+H+(H/p) log (H/p)) is presented for the parallel algorithms on distributed memory system, where M and H represent total number of the active nodes and that of the expanded nodes processed by p processors, respectively. In addition, a nearly fastest general parallel best-first B&B algorithm is put forward. The parallel algorithm is the fastest one as p = max{hε, r}, where ε = 1/ rootlogh, and r is the largest branch number of the nodes in the state-space tree.
文摘This paper presents a distributed game tree search algorithm called DDS. Based on communication overhead, st,orage requirement, speed up, and oiller factors, the performance of algorithm DDS* is analysed, and the number of nodes searched with SSS as well as a-b algorithm. The simulation test shows that. DDS* is an efficient and practical search algorithm.
基金Project supported by the National Natural Science Foundation of China （Grant No.10571117）, and the Development Foundation of Shanghai Municipal Commission of Education （Grant No.05AZ04）
文摘Given a graph G, a subgraph C is called a clique of G if C is a complete subgraph of G maximal under inclusion and ｜C｜ ≥2. A clique-transversal set S of G is a set of vertices of G such that S meets all cliques of G. The clique-transversal number, denoted as τC（G）, is the minimum cardinality of a clique-transversal set in G. The clique-graph of G, denoted as K（G）, is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques in G have nonempty intersection. Let F be a class of graphs G such that F = {G｜ K（G） is a tree}. In this paper the graphs in F having independent clique-transversal sets are shown and thus τC（G）/｜G｜ ≤ 1/2 for all G ∈F.
基金the National Natural Science Foundation of China(Grant No.10571076)
文摘In this paper,we study the strong law of large numbers and Shannon-McMillan(S-M)theorem for Markov chains indexed by an infinite tree with uniformly bounded degree.The results generalize the analogous results on a homogeneous tree.
基金This research was supported by the National Natural Science Foundation of China(Nos.11571135,11671320 and 11601430).
文摘Let G be a graph on n vertices with bounded treewidth.We use fk(G)to denote the number of spanning forests of G with k components.Given a tree decomposition of width at most p of G,we present an algorithm to compute fk(G)for k=1,2,…,n.The running time of our algorithm is O((B(p+1))^(3)pn^(3)),where B(p+1)is the(p+1)-th Bell number.
