共查询到20条相似文献,搜索用时 0 毫秒
1.
2.
高速公路监控员的主观因素往往导致交通事件现场救援组织标准的不一致,进而降低了交通事故应急响应的效率。文中提出了一种基于贝叶斯分类的交通事件分类方法。该方法使用贝叶斯算法对交通事件数据进行分类并得到每个分类的概率,通过引入条件概率,改进传统的人为判断得出救援方案的分类方法,在一定程度上降低了人为主观判断对交通事件现场救援效率的影响。实验结果表明,该方法对交通事件的分类与实际情况相符。 相似文献
3.
Accurate and real-time classification of network traffic is significant to network operation and management such as QoS differentiation, traffic shaping and security surveillance. However, with many newly emerged P2P applications using dynamic port numbers, masquerading techniques, and payload encryption to avoid detection, traditional classification approaches turn to be ineffective. In this paper, we present a layered hybrid system to classify current Internet traffic, motivated by variety of network activities and their requirements of traffic classification. The proposed method could achieve fast and accurate traffic classification with low overheads and robustness to accommodate both known and unknown/encrypted applications. Furthermore, it is feasible to be used in the context of real-time traffic classification. Our experimental results show the distinct advantages of the proposed classification system, compared with the one-step Machine Learning (ML) approach. 相似文献
4.
Accurate and real-time classification of network traffic is significant to network operation and management such as QoS differentiation, traffic shaping and security surveillance. However, with many newly emerged P2P applications using dynamic port numbers, masquerading techniques, and payload encryption to avoid detection, traditional classification approaches turn to be ineffective. In this paper, we present a layered hybrid system to classify current Internet traffic, motivated by variety of network activities and their requirements of traffic classification. The proposed method could achieve fast and accurate traffic classification with low overheads and robustness to accommodate both known and unknown/encrypted applications. Furthermore, it is feasible to be used in the context of real-time traffic classification. Our experimental results show the distinct advantages of the proposed classification system, compared with the one-step Machine Learning (ML) approach. Communication author: Li Jun, born in 1971, female, Ph.D. candidate, Associate Professor. Nanjing University of Posts and Telecommunications, Nanjing 210003, China. 相似文献
5.
该文详细地阐述音频激励信号的产生、信号电平测量、失真度测量的实现方法。重点论述了激励信号的产生、电平测量方案的选择以及失真度测量设计等。 相似文献
6.
7.
The accurate and efficient classification of Internet traffic is the first and key step to accurate traffic management, network security and traffic analysis. The classic ways to identify flows is either inaccu-rate or inefficient, which are not suitable to be applied to real-time online classification. In this paper, we originally presented an early recognition method named Early Recognition Based on Deep Packet Inspec-tion (ERBDPI) based on deep packet inspection, after analyzing the distribution of payload signature be-tween packets of a flow in detail. The basic concept of ERBDPI is classifying flows based on the payload signature of their first some packets, so that we can identify traffic at the beginning of a flow connection. We compared the performance of ERBDPI with that of traditional sampling methods both synthetically and using real-world traffic traces. The result shows that ERBDPI can get a higher classification accuracy with a lower packet sampling rate, which makes it suitable to be applied to accurate real-time classification in high-speed links. 相似文献
8.
针对机器学习分类算法的概念漂移现象,该文提出了一种基于用户连接图的(Host Connection Graph, HCG)流量分类机制。算法将{IP Address, Port}作为用户唯一标识,构建了用户连接图,提出了用户相似度的概念;应用图挖掘理论将用户连接图划分为互不相交的行为子簇,使得用户之间的相互通信抽象为一种社会团体;通过定义基于信息熵的用户行为模式(UBM),分析了各个行为子簇背后表现出的业务特征,并使用UBM+Port对用户行为子簇进行了业务标签映射,实现了流量分类的目的。仿真实验表明:在不牺牲识别准确率的前提下,算法不仅能克服概念漂移问题,还能有效降低算法的计算复杂度。 相似文献
9.
为了准确估计高速公路多个路段的交通状态,该文通过分析高速公路的路段宏观模型,提出了一种新的多路段误差状态方程。在该模型中,考虑了各路段交通密度、平均速度估计误差的传播。通过该模型,可以采用推广Kalman滤波方法进行多路段的交通状态估计。为了克服多路段状态方程的维数灾、提高计算效率并增强数值稳定性,根据系统矩阵分块的特点,该文采用了平方根滤波方法。仿真计算和实际应用表明,该文方法不仅避免了估计误差的积累效应,而且大大提高了多路段交通状态估计的计算效率。 相似文献
10.
天线的研究、设计和生产者都希望有一个理想的天线测试场.本文提出一种新的天线测试场设计方案,并在VHF频段进行了设计与实验.分析与实验结果都表明方案是成功的. 相似文献
11.
12.
《Digital Communications & Networks》2019,5(4):245-255
Mobile apps are known to be rich sources for gathering privacy-sensitive information about smartphone users. Despite the presence of encryption, passive network adversaries who have access to the network infrastructure can eavesdrop on the traffic and therefore fingerprint a user’s app by means of packet-level traffic analysis. Since it is difficult to prevent the adversaries from accessing the network, providing secrecy in hostile environments becomes a serious concern.In this study, we propose AdaptiveMutate, a privacy-leak thwarting technique to defend against the statistical traffic analysis of apps. First, we present a method for the identification of mobile apps using traffic analysis. Further, we propose a confusion system in which we obfuscate packet lengths, and/or inter-arrival time information leaked by the mobile traffic to make it hard for intruders to differentiate between the altered app traffic and the actual one using statistical analysis. Our aim is to shape one class of app traffic to obscure its features with the minimum overhead. Our system strives to dynamically maximize its efficiency by matching each app with the corresponding most dissimilar app. Also, AdaptiveMutate has an adaptive capability that allows it to choose the most suitable feature to mutate, depending on the type of apps analyzed and the classifier used, if known.We evaluate the efficiency of our model by conducting a comprehensive simulation analysis that mutates different apps to each other using AdaptiveMutate. We conclude that our algorithm is most efficient when we mutate a feature of one app to its most dissimilar one in another app. When applying the identification technique, we achieve a classification accuracy of 91.1%. Then, using our obfuscation technique, we are able to reduce this accuracy to 7%. Also, we test our algorithm against a recently published approach for mobile apps classification and we are able to reduce its accuracy from 94.8% to 17.9%. Additionally, we analyze the tradeoff between the shaping cost and traffic privacy protection, specifically, the associated overhead and the feasibility for real-time implementation. 相似文献
13.
Optical channels are currently able to carry 10 Gbit/s and even 40 Gbit/s traffic flows. However, it is not usual to have
such amounts of traffic between any pair of client nodes. This article proposes using point-to-multipoint optical channels
for the allocation of point-to-point connections in transparent wavelength-routed optical networks. Specifically, when an
optical connection between a source-destination node pair has to be established, the optical signal is also sent to some adjacent
nodes by introducing passive optical splitters; in this way a light-tree is built. Then, the already established point-to-multipoint
optical channel can be used to groom further point-to-point connections between the same source node and each of the other
nodes composing the light-tree. The benefits of this strategy are 2-fold: first, the reduction of optical transmission equipments
allowing cost savings with respect to the traditional typical point-to-point approach and, second, the optimization of the
optical channels utilization meeting in such a way Traffic Engineering objectives. The merits of proposed approach are evaluated
by simulation. 相似文献
14.
15.
针对目前P2P应用的普及,对互联网带宽的占用情况越来越严重的问题,介绍了吉林联通利用P2P流量疏导与优化系统,运用先进的P4P技术和创新模式,有效缓释电信运营商迅猛增长的P2P应用流量压力问题,并最终使得运营商具备对P2P流量和业务进行有效监控、管理和运营的能力。 相似文献
16.
17.
P. England J. R. Hayes M. Helm J. P. Harbison L. T. Florez S. J. Allen Jr 《Solid-state electronics》1989,32(12):1219-1223
We have investigated the current/voltage characteristic of resonant tunneling structures with wide well regions (80nm). We observe 25 oscillations in the current-voltage characteristic associated with resonances in the quantum well as the structure is biased to 1.0V. With the application of modest transverse magnetic fields, we see a weakening and shift of these oscillations to higher energies. We will describe how the oscillations reveal extreme hot-electron effects in the quantum well with electron mean free paths in excess of 100nm at energies approaching 1eV, and describe a theory for the phase shift which gives information on the effective mass high in the conduction band. 相似文献
18.
RPS类流量调度算法由于具有理想的延时性能,在具有QoS要求的调度算法中该类算法被广泛应用。为了使该类算法同时具有较好的公平性,将该算法与流量成形机制相结合(SRPS),即可得到理想的Worst-case公平指数(WFI)。在现有文献中部认为SRPS算法具有与WF^2Q相同WFI,本文在分析RPS算法的基础上,重新给出了SRPSworst-case表达式,指出SRPS算法具有比RPS算法理想的公平性能,但还没有达到与WF^2Q相同的Worst-case公平指数。 相似文献
19.
20.
数据产业进入了高速增长期,实现海量的数据流量分析经营成为运营商需迫切解决的问题。借助大数据相关技术,基于Hadoop架构体系提出了一套流量分析平台设计方案,并提供了详细的软件功能方案和基础架构方案,以期指导运营商流量分析类平台的落地建设。 相似文献