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1.
Nowadays the network of high-speed and broadband is required in the application of multimedia technology and information community. Many methods, such as network layering design, address design and routing are introduced to design Enterprise Backbone Network VPN's interrelation protocol is disposed and VPN tunnel is cut to establish virtual private network. Server and run plane design, bowels IP address distribution and network security advisement to design Intelligent Residential Area Network are given. It is pointed out that the method of modern network designs satisfies high-speed, intelligent and broadband for the developments of network technology.  相似文献   

2.
Based on the network planning model developed by the author for an overhaul project of a rolling mill production line in a heavy steel plant, an new multiobjective network planning model is proposed in this paper. The formulations of network time parameters are derived. The optimization problem of multiobjective network planning is also discussed. And it has been found out that the fractional single-objctive network is only one of the cases in this model.  相似文献   

3.
利用神经网络提取棉花叶片数字图像氮素含量的初步研究   总被引:9,自引:0,他引:9  
选取6种输入向量组合,利用线性网络、BP网络以及径向基网络等3种神经网络模型进行比较研究,筛选最适宜网络模型和最佳输入组合,建立叶片数字图像彩色信息和叶片氮含量的关系模型,探索利用神经网络技术获取叶片数字图像信息的方法。结果表明,径向基网络在利用数字图像(B,H,G-R,G/R)指标作为网络输入向量时,能够实现获取棉花叶片数字图像氮含量的目标。径向基网络训练的180组样本的训练精度均达到极显著水平(r = 0.9022**),30组测试样本的预测值与实测值也达到极显著相关(r = 0.8674**),径向基网络和(B,H,G-R,G/R)向量是一种适合本研究的数学模型。对利用神经网络提取棉花叶片数字图像氮含量技术的初步探索,拓展了神经网络和数字图像技术在农业生产中的应用。  相似文献   

4.
There are a large number of malicious attack nodes and collusion groups in P2P(peer to peer) network, and the existing trust models improve the P2P network environment to some extent, but the emphasis of the models are different, which are unable to fully solve large-scale malicious attacks and deception. Therefore, a P2P trust model based on equilibrium theory is presented. The model consists of the construction of the trust structure, the malicious node detection and trust speculation. It constructs trust network according to the equilibrium theory, uses the equilibrium theory to define nodes balance factor, detects balance malicious nodes by calculating the impact of malicious behavior on the network, and adopts trust inference algorithm to estimate trust nodes to prevent distrust network nodes being added. Experimental results show that the model is reliable, and the algorithm is efficient and robust.  相似文献   

5.
针对工程性基础设施网络拓扑结构不合理导致的全局性破坏问题,将社会网络分析(SNA)方法的密度、凝聚子群、K-核、Lambda集合、切点和中心度等计算概念引入基础设施网络拓扑结构评价,提出了由网络完备度、层级边关联度、局部稳定成份比例、节点脆弱性、荷载运行均衡度等指标构成的评价体系。通过对重庆长寿城区的电力基础设施实例研究发现,社会网络分析方法能够对设施网络拓扑结构与电网运行过程中的稳定性进行客观评价,能够找出电网过载点、对设施网络拓扑结构的紧凑程度和完整程度进行评价以及对网络整体的性能做出评价。  相似文献   

6.
为了快速、简便、准确地测定小麦蛋白质的含量,本文提出了应用近红外光谱分析技术结合遗传算法(GA)的BP神经网络的建模方法。采用SPXY算法对光谱数据进行了合理划分,并运用连续投影算法(SPA)将预处理过的数据压缩,对光谱数据提取最佳敏感波点作为GA-BP神经网络的输入,建立小麦蛋白质含量的校正模型。模型的预测均方根误差和预测相关系数为1.3379和0.979,并与BP神经网络所建立的校正模型进行了比较。结果表明:GA-BP神经网络所建模型收敛速度快、训练时间短、准确度也较高,能够实现对小麦蛋白质含量快速高效的检测。  相似文献   

7.
With development of broadband network application, the accessing technology of broadband network becomes an active area. Some accessing technologies, such as ADSL and HFC, have been used. But these methods do not be used widely due to their high costs. The authors discuss the widely used Ethernet technology and show how it can be deployed in broadband access network, addressing some problems need to face. Several solutions will be given, and conclusions are drawn.  相似文献   

8.
How to make use of computer network in teaching becomes the focus of concern for the computer engineers and teachers.The remote video consultation classroom can be used in teaching by using internet and NGN server to improve the instruction and stimulate the students' interest in study.As the IP network is widely used in campus,connection could be set up for student dormitory,office or even the teacher's home.On the computer network teacher and student can discuss face to face online and make best use of their time.This paper discusses the problem about how to construct a network-video class room based on computer network including VOIP and NGN(new generation network) switch server.  相似文献   

9.
In this paper, a Hopfield model for complex water quality evaluation is presented using the artificial neural network for water quality evaluation. The model is examined with the practical data of water quality from Fengzui River located at Nanchuan city in Chongqing. The results show that Hopfield network is fit for water quality evaluation.  相似文献   

10.
Based on the reactive surplus of Chongqing 220 kV main electric power network under low water and low load, and on state of higher system voltage, a thorough research is done on voltage and reactive power of the system power network by means of calculation,analysis and experiments. A main network calculating equivalence model of power network in Chongqing is constructed. And reactive power optimizing calculation is figured out on the Chongqing power network on condition that the loss minimum of the active power network is object function. Several optimizing compensatory schemes are put forward. Based on the calculation result and the analysis of all schemes, the most reasonable and feasible optimizing scheme could be achieved. Meanwhile, the feasibility that the system voltage could be adjusted when generator operating under excitation was demonstrated. According to the experience of under-excitation operation of the same type units , it decreases the system voltage, improves Chongqing power network running performance, and strengthens the coordination and stabilization of system.  相似文献   

11.
In wireless sensor network, routing protocols which based on clustering have the advantages of energy consumption, topology management and data fusion. The HEED protocol, which generates cluster heads based on distributed algorithm, drives up the rate of clustering and creates well distributed cluster heads. However, it does not consider the mobility of nodes in the network. When the distance between neighbor nodes has changed, the AMRP method which decides the node belongs to different cluster heads would cause problems such as high energy consumption, short lifetime of network and so on. Responding to these problems, the paper proposes the S HEED, a clustering algorithm based on stability, which chooses the stability as a parameter of nodes when choosing a cluster head. With S HEED algorithm, the high energy consumption problem among cluster nodes and cluster heads caused by the mobility is tackled. The simulation experiment demonstrates that the S HEED algorithm lower the energy consumption of cluster heads and prolongs the network lifetime.  相似文献   

12.
为了开展地表温度预报业务,提高逐日地表温度预报准确率,利用2007—2012年的ECMWF和T213数值预报产品资料及抚顺市的逐日地表温度资料,采用逐步回归分析方法和BP神经网络模型分别构建抚顺市地表温度预报模型,并对模型的精度进行检验。结果表明,地表温度与ECMWF的高度场、海平面气压场、温度场和T213的散度场、高度场、海平面气压场、地面气压场、海平面K指数、水汽通量、相对湿度、温度场、地面气温和场涡度场均呈显著相关。对预报模型进行精度检验显示,地表平均温度和地表最低温度的预报效果较好,≤3℃预报准确率均达到79%以上。2种模型对比显示,BP神经网络预报模型总体上优于逐步回归预报模型;逐步回归预报模型较BP神经网络预报模型稳定。  相似文献   

13.
农民创业活动已成为推动农村经济发展和农村城镇化进程的重要动力源泉,创业资源的获取是制约农民创业者的关键因素,而社会网络影响着农民创业过程中社会资源的配置,因此探讨农民获取创业资源的社会网络途径和机制有着重要的意义。运用问卷调查和统计分析的办法,就社会网络对农民创业者获取创业资源的影响作了分析,将农民创业者的社会网络按其关系密度进行了分类,深入分析了该社会网络的规模、密度、动态性和差异性,研究发现不同类型的社会网络在农民创业者获取资源过程中作用各有不同。  相似文献   

14.
A connecting platform between the field model and network model has been constructed, based on a multi functional building model. The field model is used to simulate the fire smoke in certain special compartments (the fire room and specific large space rooms), while the network model is used to simulate the uniform compartments. When combining the simulation results of the field model and network model as the interface boundary conditions for the each other, a hybrid field and network model is presented. The hybrid field network model can provide more detailed physical information of the fire smoke properties under a specific fire scenario for the specially confined compartments. In addition, the hybrid model can predict the fire smoke flow properties in the building accurately.  相似文献   

15.
16.
在分析地震条件下管线功能函数及极限状态方程基础上,对城市供水管单元体进行震害预测。以供水管网系统作为边权的有向网络图,通过基于神经网络的Monte Carlo方法,模拟各管线运行状态及其破坏状态。结合图论理论,分析供水管网的管线连通可靠性。  相似文献   

17.
The distribution system planning is performed with a loop configuration constraint from scratch.With Evolutionary Algorithm,a sample distribution network is designed with a loop configuration,in which the system is operated as radial configuration.It firstly introduces the mathematical model for distribution network planning,then the application of Evolutionary Algorithm for the planning of distribution network.By using the theory mentioned above, Visual C++ is applied to develop the distribution network optimization software.Finally with the optimization process of 17 nodes system being showed,the presented algorithm's utility and validity is verified.  相似文献   

18.
In order to find the most appropriate connection mode of 10 kV distribution network, a new approach is put forward ,in which the comprehensive weight method is applied to power system planning. At first, the main kinds of connection mode of 10 kV distribution network are introduced,then,basing on the information of subjective weights and objective weights, the performing process of the new approach is presented. It can choose the most appropriate connection mode of 10 kV distribution network sufficiently and can be calculated easily. At last, the validity and practicability of this new approach is testified with a sample.  相似文献   

19.
拟南芥APETALA1基因在花发育中的网络调控及其生物学功能   总被引:1,自引:0,他引:1  
为了阐明拟南芥花分生组织特征基因--APETALA1(AP1)基因在开花调控网络的中心位置,笔者重点综述了AP1在花发育中的网络调控及其生物学功能,探讨了花发育机制的研究重点。AP1既是花分生组织决定基因,也是花器官发育特征基因,处于成花调控网络的关键位置。AP1基因需要通过与其他调控基因的相互作用,决定花分生组织的形成、花芽的起始及花器官的发育。  相似文献   

20.
基于 SPA-RBF神经网络的小麦蛋白质含量无损检测   总被引:2,自引:2,他引:0  
传统半微量凯氏法测量小麦蛋白质含量繁琐费时,应用近红外光谱分析技术结合SPA-RBF神经网络对小麦蛋白质含量进行快速、无损检测.采用SPXY算法划分校正集和预测集样本,运用连续投影算法(SPA)对一阶微分和SNV预处理后的光谱数据提取敏感波点作为RBF神经网络的输入,建立小麦蛋白质含量的SPA-RBF神经网络校正模型.模型的预测均方根误差和预测相关系数可达到0.26576和0.975,预测效果较好,基本上可以完成粮食储备和食品加工行业对小麦及其制品品质的划分以及育种上的前期世代筛选.研究表明:近红外光谱技术结合SPA-RBF神经网络可实现对小麦蛋白质含量的检测,满足现代农业发展对小麦无损、实时、大量检测的需要.  相似文献   

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