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Improved caching policies and hybrid strategy for query result cache

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High Technology Letters 2015年第3期21卷 339-346页

作者：钱立兵 ji zhenzhou Bai Jun School of Computer Science and Technology Harbin Institute of Technology

To improve efficiency of search engines, the query result cache has drawn much attention re- cently. According to the query processing and user＇s query logs locality, a new hybrid result cache strategy which associates with caching heat and worth is proposed to compute cache score in accord- ance with cost-aware strategies. Exactly, query repeated distance and query length factor are utilized to improve the static result policy, and the dynamic policy is adjusted by the caching worth. The hy- brid result cache is implemented in term of the document content and document ids （docIds） se- quence. Based on a score format and the new hybrid structure, an initial algorithm and a new rou- ting algorithm are designed for result cache. Experiments＇ results show that the improved caching policies decrease the average response time effectively, and increase the system throughput signifi- cantly. By choosing comfortable combination of page cache and docIds cache, the new hybrid cac- hing strategy almost reduces more than 20% of the only cache and docId-only cache. average query time compared with the basic page-

关键词： query result cache hybrid caching query repeated distance caching policy

A FUNCTION NODE-BASED MULTIPLE PAIRWISE KEYS MANAGEMENT PROTOCOL FOR WIRELESS SENSOR NETWORKS AND ENERGY CONSUMPTION ANALYSIS

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Journal of Electronics(China) 2009年第5期26卷 692-698页

作者： Bi jiana Wang Hui Sun Yandong Liu Yanzhao ji zhenzhou School of Computer Science and Technology Harbin Institute of Technology Harbin 150001 China

In this letter, a Function node-based Multiple Pairwise Keys Management (MPKMF) protocol for Wireless Sensor Networks (WSNs) is firstly designed, in which ordinary nodes and cluster head nodes are responsible for data collection and transmission, and function nodes are responsible for key management. There are more than one function nodes in the cluster consulting the key generation and other security decision-making. The function nodes are the second-class security center because of the characteristics of the distributed WSNs. Secondly, It is also described that the formation of function nodes and cluster heads under the control of the former, and five kinds of keys, i.e., individual key, pairwise keys, cluster key, management key, and group key. Finally, performance analysis and experiments show that, the protocol is superior in communication and energy consumption. The delay of establishing the cluster key meets the requirements, and a multiple pairwise key which adopts the coordinated security authentication scheme is provided.

关键词： Wireless Sensor Networks (WSNs) Function nodes Key management Energy consumption

Exploration on MOOC Teaching Pilot College Construction Planning

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计算机教育 2021年第12期 81-88页

作者： Ce Zhang Dianhui Chu zhenzhou ji Songlin Gu Academic Affairs Office Harbin Institute of Technology(Weihai)Weihai264209China the School of Computer Science and Technology Harbin Institute of Technology(Weihai)Weihai264209China

The spread and innovative application of MOOC in China has rapidly triggered a profound revolution in the curriculum construction and teaching reform of universities,promoting significant results in teaching and talent *** on the practice of“MOOC teaching pilot colleges”carried out by the China University Computer Education MOOC Consortium in some universities in China,this paper proposes the overall plan of MOOC teaching pilot colleges construction through the analysis of typical cases,pointing out the purpose and significance of the reform of the pilot college and giving the relevant concepts and *** thesis focuses on the reform of teaching methods,assessment methods,grade calculation and credit recognition,and stress assessment,emphasizing the need for a three-dimensional process management of teachers,students,and college teaching administrators,and the need to focus on institutional development to provide *** teaching pilot colleges should reform and innovate in practice,and they should keep solving the problems they encounter and deepen the reform,so as to provide useful experiences and reference practices for the landing and high-quality development of MOOC teaching in more universities.

关键词： MOOC pilot college construction planning teaching reform institutional protection

An Approach of Branch Multithreading Switch Mechanism

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通讯和计算机（中英文版） 2006年第5期3卷 14-16,39页

作者： Lan Dong zhenzhou ji Mingzeng Hu Xinmin Tang Computer Science and Technology Department Harbin Institute of Technology Harbin 150001 China

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基于硬件签名的循环式内存竞争记录算法

计算机研究与发展 2014年第5期51卷 1149-1157页

作者：朱素霞季振洲李东张浩哈尔滨理工大学计算机科学与技术学院哈尔滨150080 哈尔滨工业大学计算机科学与技术学院哈尔滨150001 中国科学院计算技术研究所北京100190

多核程序的执行存在不确定性,内存竞争记录是实现多核程序确定性重演的关键技术.针对现有内存竞争记录机制记录日志较大、重演速度受限等问题,提出了一种新型的循环式点到点内存竞争记录算法.该算法用当前发生序表示内存冲突,用硬件签... 详细信息

多核程序的执行存在不确定性,内存竞争记录是实现多核程序确定性重演的关键技术.针对现有内存竞争记录机制记录日志较大、重演速度受限等问题,提出了一种新型的循环式点到点内存竞争记录算法.该算法用当前发生序表示内存冲突,用硬件签名实现冲突检测,无需修改原有的cache结构;引入冲突方向检测机制,约减连续同向的当前发生序,记录循环发生序到内存竞争日志.该算法中,内存竞争日志中所记录的任意两线程间的内存竞争呈循环状,大大减少了冗余,并用增量计数器优化循环发生序,更大程度上减小了内存竞争日志.仿真结果表明该算法能够在引入较少硬件资源的前提下有效地减小内存竞争日志.同时,内存竞争日志也具有较好的可扩展性.

关键词：片上多核处理器多核程序确定性重演内存竞争记录冲突检测硬件签名

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一种改进的分布式搜索引擎模型

哈尔滨工业大学学报 2014年第7期46卷 8-13页

作者：钱立兵季振洲吴昊哈尔滨工业大学计算机科学与技术学院哈尔滨150001

为了解决传统分布式搜索引擎存在的搜索性能问题,从索引结构、查询算法方面改进了传统模型.提出了一种非集中的高并行化搜索模型,该模型按照文档主题对索引分类,对较长的倒排记录表采用位图结构,利用多线程技术对索引节点实现并行搜索算... 详细信息

为了解决传统分布式搜索引擎存在的搜索性能问题,从索引结构、查询算法方面改进了传统模型.提出了一种非集中的高并行化搜索模型,该模型按照文档主题对索引分类,对较长的倒排记录表采用位图结构,利用多线程技术对索引节点实现并行搜索算法(multi max score heap,MMSH).实验结果表明:改进模型中的索引分类方法与倒排表结构的位图策略,能够增强Merge层查询的针对性,降低Merge层节点的CPU和内存开销;在倒排表不能完全存入内存情况下,MMSH算法能够实现高度并行化查询,其查询效率高于经典的term-at-a-time算法,缩短了平均查找时间,提高了系统吞吐量.索引分类、位图结构以及并行查询算法能够避免查询的盲目性,改善了分布式搜索引擎的性能.

关键词：分布式引擎索引分类倒排结构并行搜索

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真实感天空的实时渲染

高技术通讯 2012年第8期22卷 791-796页

作者：王纲季振洲张泽旭哈尔滨工业大学计算机科学与技术学院哈尔滨150001 哈尔滨工业大学深空探测基础研究中心哈尔滨150008

提出一种实现真实感天空实时渲染的高效方法。首先利用基于分析的天空模型实现天空的光照计算，该模型充分考虑了天空的昼夜变化，并对夜空中特有的各类光源如月球、星体、黄道光和气辉等进行分析；其次通过色调重现实现天空的真实感渲... 详细信息

提出一种实现真实感天空实时渲染的高效方法。首先利用基于分析的天空模型实现天空的光照计算，该模型充分考虑了天空的昼夜变化，并对夜空中特有的各类光源如月球、星体、黄道光和气辉等进行分析；其次通过色调重现实现天空的真实感渲染，通过对暗视效果的模拟进一步提高夜空渲染的真实感；最后给出基于观察窗口的天空几何模型和银河系、星体的渲染方法，并通过图形处理器（GPU）实现上述算法的实时渲染。该方法适用于室外场景的渲染，并已成功应用于某直升机飞行模拟器中。

关键词：天空模型色调重现几何模型实时渲染

Study on Cache Configuration of A Muitithreaded Approach

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通讯和计算机（中英文版） 2006年第7期3卷 13-15页

作者： Lan Dong Xinmin Tang zhenzhou ji Mingzeng Hu Guangzuo Cui Department of Computer Science and Engineering Harbin Institution of Technology Harbin 15000 China Modern Education Center Beijing University Beijing 100086 China

基于硬件实现的用于定长匹配的PATRICIA算法

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计算机研究与发展 2005年第6期42卷 951-957页

作者：李鑫胡铭曾季振洲哈尔滨工业大学计算机科学与工程系哈尔滨150001

PATRICIA算法是一种经典的信息检索算法,但是插入性能差、硬件实现困难.研究发现,PATRICIA算法在用于定长匹配时如果不保持NBT值的有序性,可以有效地降低硬件设计复杂度,提高插入性能.提出了一种易于硬件实现的定长匹配PATRICIA算法,证... 详细信息

PATRICIA算法是一种经典的信息检索算法,但是插入性能差、硬件实现困难.研究发现,PATRICIA算法在用于定长匹配时如果不保持NBT值的有序性,可以有效地降低硬件设计复杂度,提高插入性能.提出了一种易于硬件实现的定长匹配PATRICIA算法,证明了该算法是时间性能最优的二叉trie算法.针对状态检测技术中的状态表操作,设计了专用硬件结构实现该算法.理论和实验结果表明,该算法易于硬件实现,能够有效地对千兆网络环境的状态表进行操作.

关键词：状态表定长匹配硬件设计复杂度 PATRICIA