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POTENTIAL: A Highly Adaptive Core of Parallel Database System
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作者 文继荣 陈红 王珊 《Journal of Computer Science & Technology》 SCIE EI CSCD 2000年第6期527-541,共15页
POTENTIAL is a virtual database machine based on general computing platforms, especially parallel computing platforms. It provides a complete solution to high-performance database systems by a 'virtual processor ... POTENTIAL is a virtual database machine based on general computing platforms, especially parallel computing platforms. It provides a complete solution to high-performance database systems by a 'virtual processor + virtual data bus + virtual memory' architecture. Virtual processors manage all CPU resources in the system, on which various operations are running. Virtual data bus is responsible for the management of data transmission between associated operations, which forms the hinges of the entire system. Virtual memory provides efficient data storage and buffering mechanisms that conform to data reference behaviors in database systems. The architecture of POTENTIAL is very clear and has many good features, including high efficiency, high scalability, high extensibility, high portability, etc. 展开更多
关键词 virtual database machine virtual data bus virtual processor virtual memory parallel database
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PORLES:A Parallel Object Relational Database System
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作者 Sun Yong\|qiang, Xu Shu\|ting, Zhu Feng\|hua, Lai Shu\|huaDepartment of Computer Science and Engineering, Shanghai Jiaotong University, Shanghai 200030,China 《Wuhan University Journal of Natural Sciences》 CAS 2001年第Z1期100-109,共10页
We developed a parallel object relational DBMS named PORLES. It uses BSP model as its parallel computing model, and monoid calculus as its basis of data model. In this paper, we introduce its data model, parallel que... We developed a parallel object relational DBMS named PORLES. It uses BSP model as its parallel computing model, and monoid calculus as its basis of data model. In this paper, we introduce its data model, parallel query optimization, transaction processing system and parallel access method in detail. 展开更多
关键词 parallel object relational database BSP model data model query optimization
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An Improved Hilbert Curve for Parallel Spatial Data Partitioning 被引量:7
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作者 MENG Lingkui HUANG Changqing ZHAO Chunyu LIN Zhiyong 《Geo-Spatial Information Science》 2007年第4期282-286,共5页
A novel Hilbert-curve is introduced for parallel spatial data partitioning, with consideration of the huge-amount property of spatial information and the variable-length characteristic of vector data items. Based on t... A novel Hilbert-curve is introduced for parallel spatial data partitioning, with consideration of the huge-amount property of spatial information and the variable-length characteristic of vector data items. Based on the improved Hilbert curve, the algorithm can be designed to achieve almost-uniform spatial data partitioning among multiple disks in parallel spatial databases. Thus, the phenomenon of data imbalance can be significantly avoided and search and query efficiency can be enhanced. 展开更多
关键词 parallel spatial database spatial data partitioning data imbalance Hilbert curve
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Attenuate Class Imbalance Problem for Pneumonia Diagnosis Using Ensemble Parallel Stacked Pre-Trained Models
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作者 Aswathy Ravikumar Harini Sriraman 《Computers, Materials & Continua》 SCIE EI 2023年第4期891-909,共19页
Pneumonia is an acute lung infection that has caused many fatalitiesglobally. Radiologists often employ chest X-rays to identify pneumoniasince they are presently the most effective imaging method for this purpose.Com... Pneumonia is an acute lung infection that has caused many fatalitiesglobally. Radiologists often employ chest X-rays to identify pneumoniasince they are presently the most effective imaging method for this purpose.Computer-aided diagnosis of pneumonia using deep learning techniques iswidely used due to its effectiveness and performance. In the proposed method,the Synthetic Minority Oversampling Technique (SMOTE) approach is usedto eliminate the class imbalance in the X-ray dataset. To compensate forthe paucity of accessible data, pre-trained transfer learning is used, and anensemble Convolutional Neural Network (CNN) model is developed. Theensemble model consists of all possible combinations of the MobileNetv2,Visual Geometry Group (VGG16), and DenseNet169 models. MobileNetV2and DenseNet169 performed well in the Single classifier model, with anaccuracy of 94%, while the ensemble model (MobileNetV2+DenseNet169)achieved an accuracy of 96.9%. Using the data synchronous parallel modelin Distributed Tensorflow, the training process accelerated performance by98.6% and outperformed other conventional approaches. 展开更多
关键词 Pneumonia prediction distributed deep learning data parallel model ensemble deep learning class imbalance skewed data
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A Granularity-Aware Parallel Aggregation Method for Data Streams
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作者 WANG Yong-li XU Hong-bing XU Li-zhen QIAN Jiang-bo LIU Xue-jun 《Wuhan University Journal of Natural Sciences》 EI CAS 2006年第1期133-137,共5页
This paper focuses on the parallel aggregation processing of data streams based on the shared-nothing architecture. A novel granularity-aware parallel aggregating model is proposed. It employs parallel sampling and li... This paper focuses on the parallel aggregation processing of data streams based on the shared-nothing architecture. A novel granularity-aware parallel aggregating model is proposed. It employs parallel sampling and linear regression to describe the characteristics of the data quantity in the query window in order to determine the partition granularity of tuples, and utilizes equal depth histogram to implement partitio ning. This method can avoid data skew and reduce communi cation cost. The experiment results on both synthetic data and actual data prove that the proposed method is efficient, practical and suitable for time-varying data streams processing. 展开更多
关键词 data streams parallel processing linear regression AGGREGATION data skew
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Storage and Parallel Loading System Based on Mode Network for Multimode Medical Image Data
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作者 Xiao Zhai Haiwei Pan +2 位作者 Xiaoqin Xie Zhiqiang Zhang Qilong Han 《国际计算机前沿大会会议论文集》 2016年第2期61-62,共2页
Since Multimode data is composed of many modes and their complex relationships,it cannot be retrieved or mined effectively by utilizing traditional analysis and processing techniques for single mode data.To address th... Since Multimode data is composed of many modes and their complex relationships,it cannot be retrieved or mined effectively by utilizing traditional analysis and processing techniques for single mode data.To address the challenges,we design and implement a graph-based storage and parallel loading system aimed at multimode medical image data.The system is a framework designed to flexibly store and rapidly load these multimode data.Specifically,the system utilizes the Mode Network to model the modes and their relationships in multimode medical image data and the graph database to store the data with a parallel loading technique. 展开更多
关键词 MULTIMODE MEDICAL image data MODE NETWORK GRAPH database parallel loading
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Design and Implementation of a Heterogeneous Database System over the Intranet
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作者 姚领众 邢艳辉 +3 位作者 宋瀚涛 杨楠 郭贵锁 孙丹 《Journal of Beijing Institute of Technology》 EI CAS 1998年第1期92-99,共8页
Aim To develop a heterogeneous database united system(HDBUS)that combines the local database of Oracle, Sybase and SQL server distributed on different server into a global database,and supports the global transaction... Aim To develop a heterogeneous database united system(HDBUS)that combines the local database of Oracle, Sybase and SQL server distributed on different server into a global database,and supports the global transaction management and parallel query over the Intranet Methods In the designing and implementation of HDBUS two important concepts heterogeneous tables join. Results and Conclu- tion The first concept can be used to process the parallel query of multiple database server, the second one is the key technology of heterogeneous is the key technology of heterogeneous distribute database. 展开更多
关键词 INTRANET heterogeneous database parallel bridge heterogeneous tables join
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A parallel memory architecture for video coding
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作者 Jian-ying PENG Xiao-lang YAN +1 位作者 De-xian LI Li-zhong CHEN 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2008年第12期1644-1655,共12页
To efficiently exploit the performance of single instruction multiple data (SIMD) architectures for video coding, a parallel memory architecture with power-of-two memory modules is proposed. It employs two novel ske... To efficiently exploit the performance of single instruction multiple data (SIMD) architectures for video coding, a parallel memory architecture with power-of-two memory modules is proposed. It employs two novel skewing schemes to provide conflict-free access to adjacent elements (8-bit and 16-bit data types) or with power-of-two intervals in both horizontal and vertical directions, which were not possible in previous parallel memory architectures. Area consumptions and delay estimations are given respectively with 4, 8 and 16 memory modules. Under a 0.18-pm CMOS technology, the synthesis results show that the proposed system can achieve 230 MHz clock frequency with 16 memory modules at the cost of 19k gates when read and write latencies are 3 and 2 clock cycles, respectively. We implement the proposed parallel memory architecture on a video signal processor (VSP). The results show that VSP enhanced with the proposed architecture achieves 1.28× speedups for H.264 real-time decoding. 展开更多
关键词 Single instruction multiple data (SIMD) Video coding parallel memory skewing scheme
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面向分布式数据库的算子并行优化策略
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作者 刘文洁 吕靖超 《西北工业大学学报》 EI CAS CSCD 北大核心 2024年第3期453-459,共7页
随着网络技术的不断发展,数据规模呈现爆发式增长,使得传统的单机数据库逐步被分布式数据库所取代。分布式数据库采用节点协同工作方式解决了大规模数据存储问题,但由于增加了节点间通信开销,查询效率却不如单机数据库。分布式架构下,... 随着网络技术的不断发展,数据规模呈现爆发式增长,使得传统的单机数据库逐步被分布式数据库所取代。分布式数据库采用节点协同工作方式解决了大规模数据存储问题,但由于增加了节点间通信开销,查询效率却不如单机数据库。分布式架构下,存储节点的数据仅用作多备份的冗余,为系统故障时提供数据恢复,并未被利用起来改善查询效率。针对上述问题,提出了一种面向分布式数据库的算子并行优化策略,通过对关键物理算子进行拆分,将拆分后的子请求均匀分配到存储层多个节点,由多个节点并行处理,从而减少查询响应时间。上述策略已经在分布式数据库CBase上进行了应用,实验表明,提出的并行优化策略可显著缩短SQL请求查询时间,并提高系统资源利用率。 展开更多
关键词 分布式数据库 并行查询 查询优化 负载均衡 数据分区
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并行数据库的改进Hash划分方法及并行Join算法 被引量:4
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作者 陆丽娜 孟虹 +1 位作者 魏恒义 杨麦顺 《计算机研究与发展》 EI CSCD 北大核心 2000年第2期159-163,共5页
文中提出了Hash 划分的改进方法——IH 划分. IH划分为结点扩充时数据的重新划分提供了方便.在论述IH 划分的基础上,给出了基于该数据划分方法的并行Join 算法.利用已有的数据分布,文中提出的并行Join 算法提高... 文中提出了Hash 划分的改进方法——IH 划分. IH划分为结点扩充时数据的重新划分提供了方便.在论述IH 划分的基础上,给出了基于该数据划分方法的并行Join 算法.利用已有的数据分布,文中提出的并行Join 算法提高了算法的效率.最后,从理论上对以上并行算法的计算复杂性进行了分析. 展开更多
关键词 数据 并行数据库 数据划分 join算法
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并行数据库上的并行CMD-Join算法 被引量:5
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作者 李建中 都薇 《软件学报》 EI CSCD 北大核心 1998年第4期256-262,共7页
并行数据库在多处理机之间的分布方法(简称数据分布方法)对并行数据操作算法的性能影响很大.如果在设计并行数据操作算法时充分利用数据分布方法的特点,可以得到十分有效的并行算法.本文研究如何充分利用数据分布方法的特点,设计... 并行数据库在多处理机之间的分布方法(简称数据分布方法)对并行数据操作算法的性能影响很大.如果在设计并行数据操作算法时充分利用数据分布方法的特点,可以得到十分有效的并行算法.本文研究如何充分利用数据分布方法的特点,设计并行数据操作算法的问题,提出了基于CMD多维数据分布方法的并行CMD-Join算法.理论分析和实验结果表明。 展开更多
关键词 并行数据库 并行join算法 CMD-join算法
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一个基于Semijoin的并行join算法SBABJ 被引量:3
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作者 陈佩佩 蒋蜀 谢立 《计算机研究与发展》 EI CSCD 北大核心 1995年第5期46-51,共6页
本文在并行join算法ABJ+的基础上提出了一个基于Semijoin的改进算法SBABJ+。我们在多台Sun工作站上实现了该算法,并对ABJ十和SBABJ十进行了性能测试。算法分析和实验结果表明了并行join算法SB... 本文在并行join算法ABJ+的基础上提出了一个基于Semijoin的改进算法SBABJ+。我们在多台Sun工作站上实现了该算法,并对ABJ十和SBABJ十进行了性能测试。算法分析和实验结果表明了并行join算法SBABJ+优于ABJ+算法。 展开更多
关键词 并行数据库 并行join算法 并行处理 数据库
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基于并行B^+-树的并行Join算法的设计、分析与实现 被引量:2
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作者 孙文隽 李建中 常红 《计算机学报》 EI CSCD 北大核心 1998年第1期10-17,共8页
B+-树是一种有效的数据库存储结构,被普遍应用于各种关系数据库系统.把B+-树并行化,使之用于并行数据库系统显然是一项很有意义的重要工作.本文研究了适用于并行数据库的并行B+-树存储结构,提出两类基于并行B+-树的并行Join算... B+-树是一种有效的数据库存储结构,被普遍应用于各种关系数据库系统.把B+-树并行化,使之用于并行数据库系统显然是一项很有意义的重要工作.本文研究了适用于并行数据库的并行B+-树存储结构,提出两类基于并行B+-树的并行Join算法.理论和实验结果表明,这些算法效率高于其它并行Join算法. 展开更多
关键词 并行数据库 并行B^+-树 并行join算法 数据库
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Hash Hash^(-1)并行Join算法
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作者 金志权 葛芝宾 +1 位作者 陈佩佩 谢立 《计算机研究与发展》 EI CSCD 北大核心 1997年第S1期76-80,共5页
多处理机系统的迅速发展和商品化,促进了并行数据库系统的研制.Client/Server系统的广泛使用和大型数据库的不断增长,进一步推动了并行数据库的深入研究.文中给出了有效处理数据分布很不均匀的并行Join算法——H... 多处理机系统的迅速发展和商品化,促进了并行数据库系统的研制.Client/Server系统的广泛使用和大型数据库的不断增长,进一步推动了并行数据库的深入研究.文中给出了有效处理数据分布很不均匀的并行Join算法——HashHash-1. 展开更多
关键词 并行数据库 并行join 数据扭曲
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基于负载平衡的并行JOIN关系划分粒度研究
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作者 葛芝宾 谢立 +1 位作者 陈军 金志权 《计算机科学》 CSCD 北大核心 1995年第1期75-77,共3页
Based on the analysis of the task sizes and the load, this paper discussps the granularity ofrelation spliting in the spliting phase taking acount of task load being less than average load,andprobes into the relations... Based on the analysis of the task sizes and the load, this paper discussps the granularity ofrelation spliting in the spliting phase taking acount of task load being less than average load,andprobes into the relationship between the granularity and load balancing. The minimum number ofbuckets is determined on the basis of relation spliting granularity,and the maximum number ofproduct tuples of each node is induced under the prerequisite for ensuring load balance in paralleljoin. 展开更多
关键词 join 并行数据库 负载平衡 关系划分 粒度
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基于HRR划分的并行RDB^n树Join算法
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作者 许向阳 高东升 张勇 《计算机工程与应用》 CSCD 北大核心 2002年第8期189-191,共3页
文章首先介绍了PDBMS采用的Hash-Round-Robin(HRR)数据划分方法以及基于该划分方法的并行RDBn树,最后着重、详细地给出了基于该树的并行Join算法,分析了该算法的效率。
关键词 并行数据库 HRR数据划分 并行RDB^n树 并行连接算法 join算法
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并行JOIN算法的优化子集合调整方法
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作者 孙文隽 李建中 李金宝 《黑龙江大学自然科学学报》 CAS 1997年第3期39-46,54,共9页
子集合调整是克服数据偏斜影响的并行HASH-JOIN算法的关键组成部分,现有的克服数据偏斜影响的HASH-JOIN算法都没有很好地解决这个问题。作者深入地研究了子集合调整问题,提出了四种子集合调整算法。理论分析和实验... 子集合调整是克服数据偏斜影响的并行HASH-JOIN算法的关键组成部分,现有的克服数据偏斜影响的HASH-JOIN算法都没有很好地解决这个问题。作者深入地研究了子集合调整问题,提出了四种子集合调整算法。理论分析和实验结果都证明,这四种算法都能够很好地解决子集合调整问题,特别是启发式优化算法OP-ADJUST在多数情况下都能给出优化解。 展开更多
关键词 数据库 子集合调整 join操作 并行join算法
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解决并行JOIN中数据偏斜的一种方法
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作者 洪晓光 董继润 《计算机科学》 CSCD 北大核心 1995年第5期38-41,共4页
1.引言 最近的研究表明,数据库系统也可以利用并行处理来提高更大、更复杂查询的效,因为关系操作是面向集合的操作,本身就具有一定的可并行特性,这为查询优化在选择并行取路径时提供了很大的灵活性。
关键词 数据库 join 数据偏斜 查询优化
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一种改进的并行连接算法Diag-Join及其性能分析
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作者 庄毅 徐海力 《计算机工程》 CAS CSCD 北大核心 2004年第2期119-120,147,共3页
介绍了一种改进的并行连接算法:Diag-Join算法,并将它运用到并行环境中。实验表明,Diag-Join算法在内存足够时可以取得最好的性能,即使在内存较小的情况下,仍能得到令人满意的效果。
关键词 关系数据库 并行数据库 连接算法 索引 查询优化
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计算机机群并行环境下的并行非等值JOIN算法
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作者 郭龙江 李建中 《黑龙江大学自然科学学报》 CAS 1997年第4期36-39,47,共5页
研究在计算机机群环境下并行非等值JOIN算法的设计与实现问题,提出了两个相关的算法和实现的具体技术,实验结果表明,这些算法都是实用和有效的。
关键词 并行数据库 并行计算 计算机群 并行join算法
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