共查询到18条相似文献,搜索用时 109 毫秒
1.
《计算机工程与应用》1977,(Z3)
FORTRAN中下标变量表达式形式的数据引用被转换为包括地址运算和对主存地址的带下标引用的结果代码。因为该转换包括编译程序的所有阶段,在这里给出方法的概述。 考虑其元素长度是L的n维数组A,它的维数是D1,D2,D3,…,Dn。如果这样一个数组被分配主存开始在地址P11,那末元素A(J1,J2,J3,…,Jn)被分配在: 相似文献
2.
多维数组地址生成算法研究 总被引:3,自引:1,他引:2
高级综合系统对行为级描述中的数组元素通常用相应的存储器结构实现,行为级描述中通过数组下标对数组元素进行操作,而存储器的操作要通过存储单元地址为实现,因此需要将数组元素的下标转换成对应的存储单元的地址,该文提出一种基于普通逻辑运算的多维数组地址生成算法,该算法克服了传统的地址生成算法使用加法器和乘法器等算术运算导致的电路结构复杂、速度低等缺点,可有效地应用于支持存储器高级综合的系统中。 相似文献
3.
通过把数据立方体中的维分为划分维和非划分维,视图中的数据被分成两部分,分别存储在关系和多维数组中。针对这种混合存储结构,我们设计了一个数据立方体生成算法,它结合了流水线聚集方法和多维数组聚集方法的优点,大大减少了流水线的条数和所需要的存储空间,加快了计算速度。并用一个实际数据集进行了实验,结果表明该算法适用于计算高维的数据立方体。 相似文献
4.
C语言中,“指针与二维数组”一节是个难点,主要是二维数组的行地址与列地址容易混淆。本文把二维数组与一维数组加以对照,总结出二维数组行地址与列地址的几种表示方法。 相似文献
5.
6.
文章通过一个二维数组定义麻将的数据结构,并在此基础上设计了一种判断麻将是否胡牌的算法,该算法主要步骤的时间复杂度为O(n),且基本上处于"原地工作"。在经过算法判断运算后,该二维数组最终会恢复到最初的数据。 相似文献
7.
本文提出一个具有多种互连结构的阵列机系统,它以λ网络互连,通过PE和M之间采用流水重达技术以解决体内地址的产生问题,给出了数组乘积、FFT等基本问题的高速平行算法,系统能有效地处理各种数组向量运算。 相似文献
8.
9.
讨论了超高精度数在计算机数值运算中的算法,提出了通过利用计算机内部变量间的转换方式以及利用数组存储变量,实现超高精度数的输入、输出、存储和计算的方法。 相似文献
10.
数据立方体的预计算对于提高联机分析处理性能至关重要。在借鉴多路数组聚集完全立方体计算算法的基础上,提出了利用数据结果集驱动的完全立方体计算算法。算法在扫描完成一个方体的同时,完成方体沿各个维攀升形成的多个新方体的聚集值的计算,从而完成多路方体聚集。该算法支持大数据量立方体的计算。应用结果表明,算法可行,且易于实现。 相似文献
11.
12.
A scalable video server extracts data corresponding to the resolution requested by its client from the total data containing the information encoding a full resolution video. Depending on the requested resolution, the extracted data may not be contiguously placed on a disk or a disk array. For this reason, the traverse distance, which indicates the difference between the first read position and the last read position, can be much larger than the amount of the requested data. This causes additional rotational latency in a disk and thus degrades disk performance. Furthermore, scalable video data more seriously deteriorates the independency of disks in a disk array. That is, even a small read request can be split into multiple disk requests across disks of a disk array, because the requested data are scattered across multiple disks. To address these problems, we propose new data arrangement schemes for scalable video data. In these new schemes, we first deal with the arrangement of multi-dimensional scalable video data, which can be employed regardless of the number of scalability dimensions. Second, we improve disk performance by reducing average disk cost, which is based on both the traverse distance of each disk and the independency of disks. Third, we improve overall performance of disk devices through considering the entire request pattern, when large numbers of clients concurrently demand heterogeneous resolutions of videos from a server. We also propose fast arrangement algorithms to reduce the computation time required for searching an effective arrangement so that they can be easily applied to practical server system. 相似文献
13.
HUST—RAID磁盘阵列存储实验系统的设计与实现 总被引:3,自引:1,他引:2
磁盘阵列技术是解决计算机I/O瓶颈问题的有效手段之一。HUST-RAID系统首次把阵列技术运用于DOS环境中。本文介绍了该系统各模块的设计、功能及其工作的流程。 相似文献
14.
Bi-Ru Dai Cheng-Ru Lin Ming-Syan Chen 《The VLDB Journal The International Journal on Very Large Data Bases》2007,16(2):201-217
In order to import the domain knowledge or application-dependent parameters into the data mining systems, constraint-based
mining has attracted a lot of research attention recently. In this paper, the attributes employed to model the constraints
are called constraint attributes and those attributes involved in the objective function to be optimized are called optimization
attributes. The constrained clustering considered in this paper is conducted in such a way that the objective function of
optimization attributes is optimized subject to the condition that the imposed constraint is satisfied. Explicitly, we address
the problem of constrained clustering with numerical constraints, in which the constraint attribute values of any two data
items in the same cluster are required to be within the corresponding constraint range. This numerical constrained clustering
problem, however, cannot be dealt with by any conventional clustering algorithms. Consequently, we devise several effective
and efficient algorithms to solve such a clustering problem. It is noted that due to the intrinsic nature of the numerical
constrained clustering, there is an order dependency on the process of attaining the clustering, which in many cases degrades
the clustering results. In view of this, we devise a progressive constraint relaxation technique to remedy this drawback and improve the overall performance of clustering results. Explicitly, by using a smaller
(tighter) constraint range in earlier iterations of merge, we will have more room to relax the constraint and seek for better
solutions in subsequent iterations. It is empirically shown that the progressive constraint relaxation technique is able to
improve not only the execution efficiency but also the clustering quality. 相似文献
15.
一种提高磁盘阵列I/O性能的策略 总被引:7,自引:1,他引:6
通过资源重复途径构的磁盘阵列I/O系统,有效地提高了I/O系统的数传率和响应时间。但是、由于I/O负载大的使用环境,常规阵列控制策略不能较好地发挥阵列系统的性能。本文提出了一种适合于I/O负载变化大的改进阵列控制策略,并分析这种改进策略的I/O性能,阳后用QBENCH分别对常规策略和改进策略测试了I/O响应时间和数传率。 相似文献
16.
17.
基于索引数组与集合枚举树的最大频繁项集挖掘算法 总被引:2,自引:0,他引:2
由于其内在的计算复杂性,挖掘密集型数据集的全部频繁项集非常困难,解决方案之一是挖掘最大频繁项集。集合枚举树是最大频繁项集挖掘算法中常用的数据结构,最大频繁项集的挖掘过程也可以看作是集合枚举树的搜索过程。为缩小集合枚举树的搜索空间,采用宽度优先和深度优先相结合的混合搜索策略,提出了一种新的最大频繁项集的挖掘算法Index-MaxMiner。该算法首先设计了索引数组这种新的数据结构,并给出了一个基于二进制位图技术的索引数组的计算方法。通过为每个频繁项增加包含索引,Index-MaxMiner利用一次宽度优先搜索得到了候选最大频繁项集,使集合枚举树的第一层结点个数大幅度减少。然后在候选最大频繁项集中通过深度优先搜索,得到全部最大频繁项集,从而实现了集合枚举树的跳跃式搜索,大大缩小了搜索空间。实验结果表明,该算法可有效提高最大频繁项集的挖掘效率。 相似文献