排序方式： 共有25条查询结果，搜索用时 156 毫秒
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分布式哈希表(Distributed Hash Tabl,DHT)是一种前景广阔的对等网络拓扑模型.基于DHT的P2P系统中各种因素,例如结点异构性和不同的文件访问率等,都可能会影响DHT系统的效率.本文针对P2P的DHT算法进行了研究,并提出对其进行优化的详细策略. 相似文献
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在结构化P2P网络中,DHT搜索是一种流行的资源定位方法,它采用分布式哈希表在结点之间进行查询的"接力"。本文首先概述了DHT搜索方法的原理,然后分析了在JXTA平台上DHT搜索策略的实现。 相似文献
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马安良 《杨凌职业技术学院学报》2021,(1)
本系统以STC89C52单片机为核心,DHT11作为温湿度传感器,采集大棚农作物生长环境的温湿度参数,单片机按照预设的参数完成大棚温湿度自动控制,LCD1602显示模块显示当前的时间和温湿度参数,同时通过U盘完成环境参数实时记录,从而实现温湿度的采集→控制→实时记录。 相似文献
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Peer-to-peer (P2P) systems are now very popular. Current P2P systems are broadly of two kinds, structured and unstructured. The tree structured P2P systems used technologies such as distributed hash tables (DHT) and hierarchical clustering can search the required target quickly, however, in a tree, the internal node has a higher load and its leave or crash often causes a large population of its offspring's problems, so that in the highly dynamic Internet environment the tree structure may still suffer frequent breaks. On the other hand, most widely used unstructured P2P networks rely on central directory servers or massive message flooding, clearly not scalable. So, we consider both of the above systems' advantages and disadvantages and realize that in the P2P systems one node may fail easily, but that when a number of nodes organized as a set, which we call "super node", the set is robust. Super nodes can be created and updated aware of topology-aware, and used with simple protocol such as flooding or "servers" to exchange information. Furthermore the entire robust super node can be organized into exquisite tree structure. By using this overlay network architecture, P2P systems are robust, efficient, scalable and secure. The simulation results demonstrated that our architecture greatly reduces the alteration time of the structure while decreasing the average delay time, compared to the common tree structure. 相似文献
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The maintaining overheads of Distributed Hash Table (DHT) topology have recently received considerable attention.This paper presents a novel SHT (Session Heterogeneity Topology) model, in which DHT is reconstructed with session heterogeneity. SHT clusters nodes by means of session heterogeneity among nodes and selects the stable nodes as the participants of DHT. With an evolving process, this model gradually makes DHT stable and reliable. Therefore the high maintaining overheads for DHT are effectively controlled. Simulation with real traces of session distribution showed that the maintaining overheads are reduced dramatically and that the data availability is greatly improved. 相似文献
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王向玲 《实验室研究与探索》2020,(1):120-124
针对单片机课程实践环节薄弱的现状,以单片机典型案例"温室温湿度控制系统"为例,引入Proteus仿真软件作为课堂实践教学模式,设计了由AT89C52单片机、DHT11温湿度传感器、LCD1602、报警模块及控制模块组成的温湿度控制系统。温湿度上下限可人工设置,当超过阈值时对应的LED灯点亮、蜂鸣器报警,同时启动控制模块调节温湿度。通过Proteus仿真与课堂教学同步进行,克服了理论知识抽象的弊端,实现了理论与实践的高度融合,有利于学生创新性思维与动手能力的培养,为提高学生的学习积极性提供了便利条件。 相似文献
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基于内容的非结构化P2P搜索系统中直接影响查询效果和搜索成本的两个主要问题是,高维语义空间所引起的文本相似度计算复杂以及广播算法带来的大量冗余消息. 本文提出利用集合差异度实现基于内容聚类的P2P搜索模型提高查询效率和减少冗余消息。该模型利用集合差异度定义文本相似度,将文本相似性的计算复杂度控制在线性时间内而有效地减少了查询时间;利用节点之间的集合差异度实现基于内容的聚类,既降低了查询时间,又减少了冗余消息.模拟实验表明,利用集合差异度构建的基于内容的搜索模型不仅具有较高的召回率,而且将搜索成本和查询时间分别降低到了Gnutella系统的40%和30%左右. 相似文献
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本仓库温湿系统检测以STC89C52为控制核心,通过DHT11数字温湿度传感器,实时采集仓库环境的温度、湿度,并利用LCD液晶显示屏1602显示数据,达到实时监控温湿度的目的。 相似文献
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金敏 《贵阳学院学报(自然科学版)》2012,7(2)
结合一体化温湿度传感器与单片机的特点,设计完成了一套多通道温湿度监控系统。实现了温湿度测量与监控系统的软硬件开发。 相似文献