共查询到19条相似文献,搜索用时 109 毫秒
1.
P2P文件共享系统防止重复下载的方法研究 总被引:2,自引:1,他引:1
在P2P文件共享系统中,文件名的差异经常会导致文件被同一节点重复下载,为了降低P2P文件共享系统中摘要算法对文件进行整体和分块处理,下载前先比较文件MD5散列值的方资源重复下载率高的问题,文章提出采用MD5报文法来确定是否需要下载文件,从而有效地防止共享文件被同一节点重复下载.通过分析和利用MATLAB软件进行模拟试验,证明该方法能提高文件的下载效率. 相似文献
2.
首先通过对带通采样定理的分析,提出了正交相移键控(QPSK)高速解调器的实现方案,着重对带通采样解调算法中时钟的选取、并行匹配滤波算法、载波恢复算法和定时估计算法进行了详细描述,并用硬件编程语言编写了整个算法的代码,最后在硬件平台上下载了代码文件,验证了解调性能,测试结果表明,采用该算法实现的高速解调器在性能上有了很大的提高。 相似文献
3.
4.
P2P系统具有开放性和匿名性,这就使得恶意节点能够轻易地在网络中传播虚假的甚至有害的文件,从而损害了整个P2P系统的鲁棒性.针对该问题,文中提出了一种基于信任传递关系建立可信对等网络的算法,能够动态调整信任路径,隔离恶意节点和恶意节点集.实验表明即使在大量恶意节点相互合作的情况下,算法仍能有效地降低网络中虚假文件的下载数量. 相似文献
5.
王厚勇 《电子产品维修与制作》2009,(7):116-116
在公司或企业中,日常办公对于网络带宽有着强烈的要求。有的时候我们会同时下载很多文件,并同时浏览网页。但有的文件急需快速下载下来,如何调整带宽的优先级呢?我们可以利用NetLimiter2Pro工具来调整当前进程所使用的带宽流量,让重要的进程分的带宽多一些,不重要的则先让让路。 相似文献
6.
通过Internet,在使用AJAX方式下载文件的代码中调整存储路径,会导致在文件下载进程中,存在隐蔽存储通道的问题,隐蔽通道的存在会给信息安全带来隐患。为提高下载信息的安全性和可靠性,通过分析隐蔽通道处理技术,对隐蔽通道的存在进行改进,并设计了一种安全模型,对下载的数据信息进行隐蔽存储通道的消除和过滤,通过MD5值验证下载信息的完整,为网络下载中确保信息数据的安全性和可信性提供保障。 相似文献
7.
8.
9.
rsync算法是一种快速有效的文件同步算法,ARsync(AdvancedRemote sync)算法是对rsync的改进,在文件的同步过程中采用对同步过程分步并行化,并在计算步骤中采用流水线方法,充分利用现代计算机的多核处理机架构.在同步校验码计算方面,ARsync针对文件类型和文件结构特点,使用多粒度文件分块的方法,减小校验码总大小.ARsync将整个文件夹作为同步工作单元,采取打包压缩校验码信息的方式,使用一次完整连接来完成对整个文件夹的同步. 相似文献
10.
针对HEVC帧内预测Planar和DC模式算法的特点,提出实现这两种模式的并行化方法.该方法是通过分析推导Planar和DC模式算法之间的可并行性,以西安邮电大学自主设计的一款面向图形、图像应用的阵列处理器PAAG(Polymorphic Array Architecture for Graphics and Image Processing)平台为基础,采用最优的数据分配方式,合理地设计了多处理单元并行工作的算法程序.实验结果表明Planar预测模式和DC预测模式在多处理单元上的并行实现,相比于单核的串行运算速度分别提高了84%和81%,串/并行加速比分别达到6.34和5.44.该并行化算法减少了视频的编解码时间,其数据分配方案对于帧内预测算法在多核结构上的并行化研究也有一定的参考价值. 相似文献
11.
Keqin Li 《Telecommunication Systems》2017,64(4):719-734
It is well known that the method of parallel downloading can be used to reduce file download times in a peer-to-peer (P2P) network. There has been little investigation on parallel download and chunk allocation for source peers with random service capacities. The main contribution of this paper is to address the problem of efficient parallel file download in P2P networks with random service capacities. A precise analysis of the expected download time is given when the service capacity of a source peer is a random variable. A general framework is developed for analyzing the expected download time of a parallel download and chunk allocation algorithm, and is applied to the analysis of several algorithms. Two chunk allocation algorithms for parallel download are proposed. It is observed that the performance of parallel download can be significantly improved by using the method of probing high-capacity peers. One such algorithm is proposed and its expected parallel download time is analyzed. The performance of these parallel file download algorithms in P2P networks with random service capacities are compared. The above parallel download algorithms are extended to multiple file download by dividing source peers into clusters. It is noticed that there is an important issue of optimal parallelism which minimizes the combined effect of intracluster and intercluster overhead of parallel download and load imbalance. 相似文献
12.
基于Java的多线程下载工具研究与实现 总被引:1,自引:0,他引:1
随着人们对计算机网络资源的依赖性越来越大,获取网络信息资源已经成为使用计算机的主要目的,而资源下载是获取资源的重要途径和手段。在此针对可靠性高,质量高的Java并行多任务特点,从程序设计的角度,根据用户选择的线程数来对下载的资源进行分块等方法展开论述,分析了基于Java技术进行多线程下载的原理。从状态、块对象、资源大小计算、上下文对象等方面分析了资源对象的创建方法,讨论了文件下载过程中下载、暂停、继续、保存等模块实现方法,给出了一个基于Java技术的多线程下载工具设计流程。经过测试,文件的下载速度得到了改善。 相似文献
13.
14.
This paper proposes a cache replacement scheme named group replica caching for optical grid networks. In optical grid networks, data files for job execution are replicated at multiple servers in order to distribute loads. Clients download these files via lightpaths and store them as necessary. File downloading is blocked when the corresponding lightpath cannot be established. The blocking probability of file downloading depends on location of files. The case where a file is stored in a client is ideal because blocking of lightpath establishments does not occur. However, the storage size of the client is limited. In order to efficiently use storage resources of clients, our proposed scheme focuses on the fact that clients can download files stored in surrounding servers with low blocking probability. The proposed scheme regards a group of storages of a client and its surrounding servers as one storage. In particular, they preferentially store different files. By doing so, the probability that a file is stored at the client or its surrounding servers increases. Through simulation experiments, we show that the proposed scheme improves the blocking probability of file downloading efficiently. 相似文献
15.
In optical grid networks, data files for job execution are replicated at multiple sites in order to distribute loads and achieve
high performance computing. Those replicas are downloaded in parallel in order to reduce downloading time. Furthermore, each
replica is downloaded with multiple wavelengths. Although parallel and multi-wavelength downloading reduce downloading time,
they raise blocking probability of file downloading. This is because they use a lot of wavelength resources and thus often
generate bottleneck links. To resolve this problem, this paper proposes a parallel and multi-wavelength downloading scheme
for optical grid networks. The proposed scheme provides replica selection, route selection, and wavelength selection for parallel
and multi-wavelength downloading. In the proposed scheme, clients dynamically select combinations of a replica, a route, and
a wavelength in such a way that they suppress the generation of bottleneck links. Through simulation experiments, we show
that the proposed scheme efficiently improves blocking probability of parallel and multi-wavelength downloading. 相似文献
16.
17.
介绍了以Xilinx公司Airtex-7系列FPGA为主控芯片的文件存储系统的实现。系统实现了即插即用、工作模式自动识别的文件存储系统。可进行文件存储、下载、删除,以及格式化操作;本系统可以作为任何数据采集系统的后端文件存储/下载实现方案,具有广泛的通用性 相似文献
18.