OBS中支持QoS的增强型自适应偏置时间算法

在基于恰量时间(Just-Enough-Time,JET )信令的无光缓存光突发交换(OBS)网络中,根据网络负载和服务质量(QoS)要求灵活进行偏置时间(Offset Time,OT)设置的问题,文章提出了一种使用增强型学习机制计算OT的算法,使得OT能够随着网络载荷的变化进行自适应调整,并能支持QoS,从而能较好地适应网络状态的变化.仿真结果表明,该算法可以在不同的网络状态下有效地降低端到端的延迟和阻塞率,并能很好地提供QoS服务.     

一款模数转换器件的初始化设计方法

本文主要介绍了如何采用模拟I2C总线技术,通过使用类似AT89C2051这类没有I2C接口的系列单片机实现AD9883的初始化设计.并且介绍了模拟I2C总线应用程序设计的方法,对程序进行仿真给出仿真结果.     

CCP协议介绍及基于Matlab的CCP MCD实现

CCP协议是车载电子系统比较通用的一类匹配标定协议。文章介绍了该协议的基本原理和具体实现中的技术特征,重点讨论了CCP协议中采用数据采集模式进行匹配标定的机理和特点。结合协议介绍,文中还介绍了基于Matlab平台的CCP MCD设备的实现。实践证明,Matlab具有较好的开放性,并且可以方便地通过Simulink和Stateflow完成CCP协议中必须要求的时序机制。因此基于Matlab平台的CCP MCD设备具有一定的技术先进性和实用性。     

Novel design for small-size coplanar waveguide frequency tripler

This letter presents a novel design for a small-size coplanar waveguide frequency tripler. In this study, a new BPF has been replaced the conventional stub lines in the output termination of the multiplier. Not only enhance the performance of the tripler, but also reduce the whole circuit size. to 2.125/spl times/2.275 cm/sup 2/ in the frequency 0.8/2.4 GHz, The spurious suppressions are 37.48, 33.38, and 32.08 dBc for the 1st, 2nd, and 4th harmonics, respectively. It reveals the best output power of -1.92 dBm for a 0 dBm input signal and maximum conversion gain of -1.92 dB. It is very useful for applications in the wireless communication and radar systems.     

A Safe Proactive Routing Protocol SDSDV for Ad Hoc Network

In mobile Ad Hoc network, nodes move freely, this can lead to frequent changes of network topology. Routing protocol algorithm is the strategy to establish communication links for network nodes, and its performance influences the availability of Ad Hoc network directly. By using wireless channel to transmit data in Ad Hoc network, the invaded malicious nodes will cause various attacks, aim to steal the transmission data or destroy the network. Based on the traditional proactive routing protocol for Ad Hoc network, an improved safe routing strategy SDSDV is put forward to resist attacks against routing protocols. The safe proactive routing protocol includes route request and route response two stages. When the network initialization is complete, after successful identity authentication by each other, secure communication paths are established between nodes and the encrypted data will be transmission through the path. The protocol integrates distributed authentication, encryption algorithm, hash check, and other security policy together. SDSDV protocol reduces the risk of malicious manipulation of routing information and ensures the safe and reliable routing between the source and destination nodes.     

Speech authentication and content recovery scheme for security communication and storage

With the rapid development of Internet, it brings a lot of conveniences. However, the data transmission and storage are faced with some security issues that seem to be obstacles to overcome, such as privacy protection and integrity authentication. In this paper, an efficient speech watermarking algorithm is proposed for content authentication and recovery in encrypted domain. The proposed system consists of speech encryption, watermark generation and embedding, content authentication and recovery. In the encryption process, chaotic and block cipher are combined to eliminate the positional correlation and conceal the statistical feature. In the watermark embedding process, approximation coefficients of integer wavelet transform are used to generate watermark and the detail coefficients are reserved to carry watermark. Theoretical analysis and simulation results show that the proposed scheme has high security and excellent inaudibility. Compared with previous works, the proposed scheme has strong ability to detect de-synchronization attacks and locate the corresponding tampered area without using synchronization codes. Meanwhile, the selective encryption will not influence the selective watermarking operation. Similarly, the operation of watermarking will not affect the decryption of the encrypted speech. Additionally, the tampered samples can be recovered without any auxiliary watermark information.     

一种新的大规模网络主动预警方法

网络的全球化发展决定网络安全向整体性和动态性发展,互联网的分散管理机制使得监控管理域外的网络安全状态变得非常困难.本文基于网络透视技术,提出一种新的大规模网络主动预警方法,可以对无控制权的网络进行实时监控和主动预警.当网络发生异常行为时,能够准确检测异常来源,缩小异常定位范围,对于大规模网络异常行为的检测和预防具有重要现实意义.以中国教育网拓扑结构为背景的仿真实验表明,该方法有效,对网络安全具有重要的研究意义和实用价值.     

数字家庭网络发展分析

随着宽带接入业务、智能家电等电子产品的普及以及用户对家庭电子产品的监控和资源共享需求的上升,数字家庭网络的概念和应用受到电信运营业和IT、家电产业的关注.本文介绍了不同行业对数字家庭网络概念的理解,对数字家庭网络相关的关键技术发展现状进行了分析,并总结了目前国际上数字家庭网络的市场发展现状.     

基于车间式的“冲压工艺与模具设计”课程改革实践

本项目打破传统的虚拟"车间式教学"模式,将我校模具设计与制造技术的专业核心课——《冲压工艺与模具设计》的教育基地定在长春市一汽模具制造有限公司,进行现地现物教学。根据岗位职业能力需求,与企业共同制定课程标准。将专业课程与企业的生产任务深入融合,形成产教融合,工学结合的教学模式。     

一种带故障报警的漏电保护器电路设计

传统的小型漏电保护期没有故障自检功能,即使产品出现问题也没有告警。在这种情况下,如果真的有了漏电故障,就可能造成人身伤害,设备故障或者火灾。本设计利用常用的逻辑器件实现自动检测产品出现的故障功能,并给出故障报警。故障检测包括脱扣线圈检测,机械故障检测和内部的直流电源电路检测。