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1.
可重构造的网孔机器上的k-选择   总被引:2,自引:0,他引:2  
对于一个 m ×n(m ≤k)的列有序矩阵,文中在 n × n 可重构造的网孔机器上提出了一个并行 k选择算法,其时间复杂度为 O(log2m + logm log2 n+ log3 n),而对于一般的l元集,文中在相同的模型下提出了一个时间复杂度为 O log2 ln + log ln log2 n+ log3n+ ln log ln 的并行 k选择算法.当时 l≥ O(nlog3n/log logn,该时间复杂度为 O ln log ln .特别地,当l= O(n1+ ε)(ε> 0 为常数),则时间复杂度为 O ln logn .此时达到的加速比为 n/logn.  相似文献   

2.
一类扩展的Steiner树优化问题及其应用   总被引:1,自引:0,他引:1  
本文提出了一个计算机网络通信和分布式系统中的一类扩展的Steiner树问题.对此问题设计了两个求其最优解的算法.这两个算法的时间复杂性分别是O(3(k-1)·n+2(k-1)·n2)和O(2(n-k)·n2).其中,k是一棵Steiner树需支撑的给定顶点的个数.  相似文献   

3.
本文介绍了0-1背包问题的一种深度优先(DFS)算法,并用概率分析方法给出了算法的时间复杂度和空间复杂度,一般情况下,其时间复杂度在O(n)到O(1.5)之间。工程管理上的一类整数规划问题都可归结为0.1背包问题。  相似文献   

4.
文中用合并选择的思想及堆上的最佳算法,给出了求解选择问题的一个新算法及其相应的并行化。将串行合并选择算法的复杂度nLogk+O(n)降低到(nLogk)/2+(nLogLogk)/2+O(n),并保持了原并行算法的结构,在SIMD树型机器的并行计算模型上,并行运行  相似文献   

5.
Chent等研究了n-Star网络中的点到多点并行路由问题,对前人的工作做了很大的改进,给出了一个几乎最优的时间复杂度为O(n^2)的算法,由Chen的算法所给出的n-1条路P2,…,Pn满足│Pi│≤dist(v1,vi)+6,其中Pi是连续vi到v1的路,│Pi│表示路Pi的长度,dist(v1,vi)表示vi到v1的最短路的长度。  相似文献   

6.
连通分量和最小生成树是图论中的两个基本问题 ,在许多领域都有很多应用 .对于顶点数为 n的图和规模为 p× p的虫孔路由二维网孔机器 ,该文针对 p n和 n

相似文献   


7.
最小生成森林的边更新在网络路由等方面有着重要的应用价值 .给定 n个结点的无向加权单图 G,该文首先在 n× n的二维可重构造网孔机器上提出了在 O(1)时间内判断 n个结点的无向图的连通性和在 O(logn)时间内求 n个结点的内向树中任一结点到根的路径两个算法 ,并在 n× n× n的三维可重构造网孔机器上提出了 O(1)时间内求 n个结点内向树中任一结点到根的路径的算法 .然后在上述算法的基础上提出了两个 G的最小生成森林的边更新算法 ,一个运行在 n× n的二维可重构造网孔机器上 ,时间复杂度是 O(logn) ,另一个运行在 n× n× n的三维可重构造网孔机器上 ,时间复杂度是 O(1) .  相似文献   

8.
完全欧几里德距离变换的最优算法   总被引:12,自引:2,他引:12  
陈Leng 《计算机学报》1995,18(8):611-616
欧几里德距离变换(EDT)对由黑白素构成的二值图象中所有象素找出其到最近黑素的距离,应用于图象分析,计算机视觉,在本文之前,该问题的最好复杂度为O(n^2logn)。本文提出了一个复杂度为O(n^2)的算法,使复杂度达到最优,该算法可以并行化,在有r个处理单元的EREWPRAM计算模型上,若rlogr≤22/6n,则时间复杂度为O(n/r)否则为O(nlogr)。  相似文献   

9.
最长公共子充列问题的改进快速算法   总被引:1,自引:0,他引:1  
现在几个最常用的解决最长公共子序列(LCS)问题的算法的时间复杂度分别是O(pn),O(n(mp))。这里M、n为两个待比较字符串的长度,P是最长公共子串的长度。给出一种时间复杂度为O(p(mp)),空间复杂度为O(m+n)的算法。与以前的算法相比,不管在P〈〈m的情况下,还是在P接近M时,这种算法都有更快的速度。  相似文献   

10.
本文首先把迷宫排序问题推广为m×n迷宫(m>1,n>1)的排序问题,证明了m×n迷宫的任一初始状态能经过有限步移动转变成目标状态的充要条件,然后给出了一个m×n迷宫排序的算法,该算法的时间复杂度是O(mn(m+n)),空间复杂度是O(mn).最后还指出了它的时间复杂度的一个下界.这样,关于迷宫排序问题就基本上得到了圆满地解决.  相似文献   

11.
Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.  相似文献   

12.
European Community policy and the market   总被引:1,自引:0,他引:1  
Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.  相似文献   

13.
融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。  相似文献   

14.
Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.  相似文献   

15.
This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.  相似文献   

16.
Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008  相似文献   

17.
Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.  相似文献   

18.
This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)SM and Team Software Process (TSP){SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.  相似文献   

19.
基于复小波噪声方差显著修正的SAR图像去噪   总被引:4,自引:1,他引:3  
提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。  相似文献   

20.
Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.  相似文献   

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