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1.
According to the simulation results, the factors causing the forming of self-similarity in IP network is presented. Through analysis based on ON/OFF model, we show the influence of traffic source integration level on self-similarity degree. Using the above results, an IP network traffic generator is implemented. Tests in real environment show that the generator can better reflect the relationship of file sizes, protocol types, ON/OFF residence time, traffic source integration levels and self-similarity degrees.  相似文献   

2.
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   

3.
On the basis of analyzing connotation of congestion pricing,through the qualitative analysis of the main content and implementation effect of the congestion policy in cities such as Singapore,London and Stockholm,the basic conditions for urban congestion charges were summarized.Compared with Beijing’s urban development,traffic development status,urban transport infrastructure and social factors,the current policy of traffic congestion charging is still not available from the perspective of the current status of car ownership in Beijing,residents’ travel composition,and population density distribution.  相似文献   

4.
The prediction of network traffic flow is a problem of great significance in the research work of resource allocation and congestion control. Based on this accurate prediction, the scheme of resource allocation and control can easily adapt to dynamic variations of incoming traffic flow. So the goal of optimal network performance is achieved. There are many sorts of traffic flow of self-similarity characteristics in high-speed network, and some research work has showed this self-similarity keeps in close contact with the attractor of chaos system. A rate prediction of self-similar traffic sources in high-speed network is proposed as well as the maximum of predictable time by applying the technology of phase space reconstruction about chaotic time series. This method has a simple prediction mode, and the result of simulations indicates it also has highly accurate results.  相似文献   

5.
“生物工程设备”是生物工程专业的核心必修课程,是一门知识面广、实践和应用性强的课程。以工程教育认证为导向并结合多年的教学过程,对教学内容进行优化与改革、对教学手段与方法进行,以及对实践教学等方面进行了有益的探索与实践,获得了一些提高教学效果、培养学生工程实践能力的教学经验。  相似文献   

6.
基于综合能力培养的“食品工程原理”理论教学方法探讨   总被引:1,自引:0,他引:1  
“食品工程原理”是一门重要基础专业课,做好其理论教学是该课程其他教学环节顺利进行的前提。在新工科背景人才培养的背景下,以培养学生自主学习能力为出发点,从课前、课上、课后3个方面阐述了“食品工程原理”理论教学改革的具体措施,实现“食品工程原理”理论教学效果提高,促进学生独立解决问题和团结协作等综合能力的培养。  相似文献   

7.
中国西部地区生态农业工程的开发与建设   总被引:2,自引:0,他引:2  
徐峰  曹林奎 《中国农学通报》2005,21(11):347-347
生态农业既代表全球现代农业发展的新途径,又代表可持续农业发展的一种具体形式。加强中国西部地区生态农业的开发建设,必将有利于西部地区农业的全面开发,并推动该地区农村经济的发展。西部地区生态农业建设可重点开发以下四大工程:农田生态建设工程、林业建设工程、绿色食品开发工程和旅游农业开发工程。  相似文献   

8.
"食品工程原理"课程的理论教学难度大、实践教学的局限性造成本科生知识体系掌握不足和实践训练缺乏等问题,结合实际生产数据开发的切达干酪虚拟仿真操作平台,采用干酪加工作为载体的大案例贯穿全课程教学,衔接各个单元操作及章节内容,通过学生的虚拟仿真实验操作充分发挥其主观能动性,并结合学生反馈信息,将重点难点的理论知识进行针对性课堂讲解,以增强教学效果的一种教学方法。结果表明,教学班与对照班相比成绩极显著提高,对提高学生兴趣、发挥主动性、避免填鸭式教学的弊端等方面起到积极作用。  相似文献   

9.
With improvement of construction management and development of computer and network technologies, network technologies are being widely applied in building engineering. This paper discusses how to apply database technology and network technology to design and develop information network systems of building engineering and combine the advanced management methods with computer network technology to share the quality information in construction industry. The solution given by this paper is useful and can be extended to and used in other systems.  相似文献   

10.
通过对基质固相分散淋洗剂、样品填料比等处理条件的优化研究,建立了葡萄酒中9种有机磷农药残留检测的分析方法,即基质固相分散—气相色谱—质谱联用法。加标结果表明,9种有机磷的回收率为66.98%~105.91%,相对标准偏差小于7.5%,检出限为0.0066~0.027mg/kg,可用于葡萄酒样品中农药残留的测定。  相似文献   

11.
How to remove the background , to eliminate the misdetection caused by vehicle changes road or it covers the detection window of the road detected partly, is a big problem to be handled in vehicle detection system.This paper presents an improved frame-difference method based on Video,and describes how to detect and count vehicles in detecting zone dynamically.With this method, we can count the vehicles passing by accurately, collect the traffic flow of each roadway reliably.We provide real-time traffic parameters for the ITS.  相似文献   

12.
According to the need of engineering cost management reform and with the development of computer technology, application of Internet and establishment of national and local engineering cost information system, the construction company should have their engineering cost information system. Especially, there should be the dynamic information system for dynamic management of engineering cost to promote the reform of engineering cost management and satisfy the need of company development.  相似文献   

13.
This paper proposes a novel BP network model based on nonlinear iterative partial least-squares algorithm which can fit nonlinear data. The novel BP network model can reduce iterative step number and advance learning effieieney. This paper pretreats data by nonlinear iterative partial least-squares algorithms. The weights initialization of input floor and output floor are set by applying the loading weights of dependent variable and cause variable, the member of hidden nodes are set by applying factor numbers of nonlinear iterative partial leastsquares algorithm, the connection co- efficient is set by applying the connection matrix B. Performances of the BP, PLS, and PLS-BP are analyzed and compared. The results show that the PLS-BP has better fitting and forecasting than BP and PLS.  相似文献   

14.
With the development of the academic degrees and graduate education, evaluation is the important measure for guaranteeing the quality in the area. With increasing complication of the target of the evaluation of academic degrees and graduate education , it is necessary to introduce nonlinear method of the evaluation, which has great significance for the validity of the result of the evaluation. Neural networks have been developed greatly in recent years,they have the advantages of nonlinear mapping,parallelity ,adaption, etc. Therefore , they are good tools of nonlinear modeling. On the basis of setting up the model of the evaluation based on neural network ,this paper presets the practical value of the method.based them.  相似文献   

15.
采用基质固相分散萃取-气相色谱(MSPD-GC)技术,建立丹皮中有机氯和拟除虫菊酯农药多残留分析新方法。以回收率为指标,采用正交设计优化选择填料种类,样品与填料量的比例、淋洗液的极性。丹皮样品与中性氧化铝(m/m,1:2)充分研磨5 min后装入10 mL玻璃层析柱内,通过10 mL乙酸乙酯洗脱,11种农药在0.02、0.1、1 mg/kg 3个添加水平的平均回收率为77.69%~110.7%,相对标准偏差均低于11.6%,方法检出限在0.1~3.4 μg/kg范围。该方法可同时监测丹皮中有机氯、拟除虫菊酯类等农药的残留水平,方法简便。  相似文献   

16.
Both tenderees and tenderers attach much importance to contractor prequalification before bidding because it plays important roles for both and so far the Score Method has been widely used in our country. But the weights in the method are man-made, which may be affected by personality inevitably. In order to avoid this influence, this thesis will introduce another method based on artificial neural network. This thesis expatiates the principle of artificial neural network, and analyzes the characters of prequalification. Then, the author sets up the mathematics model. In the end, the author analyzes this method by an example.  相似文献   

17.
在构建“生物统计学”课程网络教学平台的基础上,对3个教学环节共77名本科生利用该平台进行的教学活动及教学改革实践进行了研究,旨在进一步提高该课程的教学水平和教学质量。结果表明:利用网络教学平台,有利于开展网上互动式教学活动;有利于强化教学实践环节;有利于同学们学以致用并扩大学科视野。SAS统计分析结果表明,代表学生网上学习能力的网上“阅读讲义次数”与学生的学习成绩密切相关,达极显著水平(R=0.6004**)。  相似文献   

18.
基于纹理特征和神经网络的图像识别   总被引:1,自引:0,他引:1  
徐硕  王洲 《中国农学通报》2007,23(9):590-594
图像特征是用来区分图像内部最基本属性或特征的,它包括了几何特征、形状特征、颜色特征、纹理特征等,在这些特征中纹理特征理解过于复杂,至今尚未有一个大家都认同的定义,从而也就使得纹理分析变得很困难。该文主要研究图像的分类识别,采用基于灰度共生矩阵的纹理特征的提取。以8位灰度图为研究对象,依次对图像进行4个方向(0°、45°、90°、135°)的扫描,并分别建立灰度共生矩阵,从而提取纹理特征参数,然后建立BP神经网络模型,用提取的纹理特征值,来训练BP神经网络模型,使网络模型能够识别图像的内容。此文提出了用纹理特征训练神经网络的方法来识别图像,研究结果表明,纹理是图像分析中一个非常重要的特征,所提取的图像特征是描述图像相当有效的参数。  相似文献   

19.
The governing system of hydraulic turbine generator plays an important role in power system. It is significant to find out the faults of governing system and remove them quickly. This paper sets up a new fault diagnosis model of the hydraulic turbine generator governing system with the advanced ANN (artificial neural net). This 17-in-13-out model consists of three layers. It is proved that this model can find the fault accurately.  相似文献   

20.
The worst and best-case coverage algorithm is presented based on probability mode of wireless sensor network. The main idea is that choose these lattice points possibly with lowest detection probability by nodes to form the most breach path and choose those lattice points possibly with maximal detection probability by nodes to form the most support path. Simulation experiment validates the algorithm.  相似文献   

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