光驱和刻录机共用数据线导致的故障

笔者的一位朋友最近在用N e r o刻光盘的时候发现,只要刻录机在刻录,CD-ROM光驱(明基52×)就无法读取。直至产生Buffer Under Run错误使刻录机停止刻录,CD-ROM光驱才恢复读盘。同样,当CD-ROM光驱在读盘时,刻录机就不能刻录。根据笔者的观察,这是因为两台光驱同时使用同一条IDE线来传递数据,阻塞了IDE通道,这样,当一台光驱读盘时,另一台光驱就会暂停工作。解决的方法就是改变一下安装光驱的方式,把这两台光驱分接到两个不同的IDE通道上。可考虑把CD-ROM光驱连至与硬盘同一条IDE通道上(即同时用一条IDE排线),而让刻录机独自使…     

基于双信道的Ad Hoc网络的路由框架模型

针对Adhoc网络提出了一种双通道控制策略模型(DCRF)。在该模型中通过一条通道用来传输网络所有节点状态信息,而另一条通道通过前者的状态信息来传输数据信息。这样可以提高获得最有效路由的概率,同时降低了控制分组的开销且避免了控制分组对信道带宽的损耗,改善了网络性能。仿真验证了方法的有效性。     

基于2D-Mesh的容错路由算法

提出一种基于2D-Mesh只使用2条虚通道的容错路由算法,少于需要4条虚通道的Boppana算法,以及需要3条虚通道的Duan算法。算法基于块故障模型,故障块可以是f-ring,也可以是f-chain。无故障时算法用最短路径路由消息,当消息被故障块阻塞时使用绕道策略进行路由。在不重叠和重叠故障区情况下分别给出算法无死锁性的证明过程。     

SSL VPN的五大亮点

SSL VPN可以通过特殊的加密通讯协议,在Internet一端的出差员工和另一端的公司总部之间建立一条专有的通讯通道,就好比架设了一条专线。与传统VPN解决方案相比较,SSL VPN使用维护简单,不用更改现有网络结构,移动性强,无需安装客户端程序,具有强有力的访问控制能力,可以使移动用     

双发并收的高可靠性SDH传输方式

本文提出了一种双发并收的高可靠性SDH传输方式。该方式通过对电力生产实时信号的双发并收,使信号在多条独立的2M通道上并行传输。当部分通道出现误码越限或中断时,信号仍可通过余下的通道传输,而不需要在SDH设备进行通道倒换。双发并收消除了通道倒换的影响,降低了传输的误码率,提高了信号的传输可靠性。     

“蜂窝”走向第三代 诺基亚和爱立信支持宽带码分多址技术

6月23日获悉:诺基亚和爱立信公司联合宣布支持用于第三代宽带蜂窝系统的宽带码分多址技术(简称WCDMA)。 WCDMA系统可使用户只用一个终端享受到多种服务。对于使用GSM技术的公司来说,WCDMA提供了又一条向第三代无线技术过渡的通道,不间断地支持漫游和便携功能。据估计,到2001年,当第一     

攻略 末日星河实战篇

第一章 群星灿烂 当地球人发现了Rigel Kentaurius附近的行星Congita,并在那里建立了殖民地以后,每个人都知道找到另一个这样的行星只是时间早晚的问题。我们很清楚我们应该做什么,而地球就像细心呵护孩子的父母一样注视着他们的孩于离开家园。”地球总部:“戴维,这里是巴西2号,请注意在打开传送通道前先清理太空。”任务:摧毁或采集该区域内的所有小行星。 第二章 今夜星空将落 当小行星被清除干净后,安格拉斯向戴维报告在火星附近发现一颗慧星,经过计算它正向地球撞去。在向人类从未见过的外     

基于卷积神经网络的短文本情感分类

近年来,卷积神经网络模型常常被用于文本情感分类的研究中,但多数研究都会忽略文本特征词本身所携带的情感信息和中文文本分词时被错分的情况.针对此问题,提出一种融合情感特征的双通道卷积神经网络情感分类模型(Dual-channel Convolutional Neural Network sentiment classification model fused with Sentiment Feature,SFD-CNN).该模型在构造输入时以一条通道构造融合情感特征的语义向量矩阵以获取到更多的情感类型信息,以另一条通道构造文本字向量矩阵以降低分词错误的影响.实验结果表明,SFD-CNN模型准确率高达92.94％,要优于未改进的模型.     

2333MHz!金士顿骇客神条性能再创新高——全球最快的通过Intel认证的三通道内存

全球第一大独立内存模组制造商——金士顿6月1日隆重宣布,推出通过Intel认证的全球最快的DDR3三通道骇客神条（HyperXo可在2333MHz超高频率下稳定工作,金士顿DDR3三通道骇客神条（料号：KHX2333C9D3T1FK3／6GX）于Corei7平台上获得IntelXMP认证。     

远程可视化辅助决策支持系统的建立及在生产中的应用研究建设

远程可视化辅助决策支持系统的建立紧密贴近生产实际,为解决生产实际问题开通了一条便捷、高效的信息通道。该系统将公司现有专用系统及专业系统进行整合,建立了内容管理平台、沟通协作平台、系统集成平台、应用统计分析平台,实现公司对资产管理上的远程应急响应及技术决策支持。     

On the reliability function for a BSC with noisy feedback

A binary symmetric channel is used for information transmission. There is also another noisy binary symmetric channel (feedback channel), and the transmitter observes without delay all outputs of the forward channel via the feedback channel. Transmission of an exponential number of messages is considered (i.e., the transmission rate is positive). The achievable decoding error exponent for this combination of channels is studied. It is shown that if the crossover probability of the feedback channel is less than a certain positive value, then the achievable error exponent is better than the decoding error exponent of a channel without feedback.     

On the zero-rate error exponent for a BSC with noisy feedback

For information transmission, a binary symmetric channel is used. There is also another noisy binary symmetric channel (feedback channel), and the transmitter observes (without delay) all outputs of the forward channel via the feedback channel. Transmission of non-exponentially many messages is considered (i.e., the transmission rate is zero). The achievable decoding error exponent for this combination of channels is investigated. It is shown that if the crossover probability of the feedback channel is less than a certain positive value, then the achievable error exponent is better than the similar error exponent of the no-feedback channel. The described transmission method and the corresponding lower bound for the error exponent can be improved, as well as extended to positive transmission rates.     

移动Ad Hoc网络中基于ID的信道预约多址接入协议

为了在移动ad hoc网络中有效利用无线信道资源,提出一种基于ID的信道预约(ID-based channel reservation,简称IDBCR)多址接入协议.该协议在公共信道上发送Request-To-Send/Clear-To-Send(RTS/CTS)分组实现握手,采用基于节点ID的信道选择方案选择无冲突的业务信道传输数据分组,目的节点成功接收完数据分组后在另一个公共信道上回复acknowledgment(ACK)分组,有效避免了暴露终端问题.最后,仿真实现了IDBCR协议,并与CAM-MAC(cooperative asynchronous multi-channel MAC)多信道协议比较.结果表明,在总信道利用率、平均信道利用率和平均分组延迟性能上,IDBCR多址接入协议明显优于CAM-MAC协议.     

Analysis of models of the integral cellular communication network with different schemes of channel partitioning

Two schemes of partitioning the shared channel pool between the calls of speech and data in the integral cellular communication networks were proposed. One uses the isolated partitioning procedure, the other, the virtual partitioning. The isolated partitioning forbids channel reassignment from one zone to another, whereas the virtual partitioning relies exactly on this procedure. In both schemes, the voice calls first occupy the free channels in their zone, and only if the channels of this zone are occupied, then a free channel is sought in another zone only for the handover voice call. In this case, the maximal number of handover speech calls in the zone of channels for data calls is limited. A scheme constraining the access of such calls depending on the total number of data calls in the cell is used to establish a rule for access of new data calls to the channels. Methods were developed to calculate the indices of service performance with the proposed access strategies. The results of numerical experiments were presented, and for different access strategies the indices were compared.     

Performance analysis of CSMA and BTMA protocols in multihop networks (II). Multiple channel case

Busy tone multiple access protocols have been used in multihop networks to reduce the effect of the hidden terminal problem. This paper demonstrates another approach to reduce the effect of the hidden terminal problem namely the use of multiple channel schemes. A protocol that uses both the busy tone and the multiple channel techniques achieves the best performance. Using a Markov chain model and an approximation, the throughput performance of the multiple channel non-persistent CSMA protocol and the multiple channel conservative BTMA protocol in a large network is evaluated and compared. The results show that the multichannel CSMA and BTMA schemes exhibit a better performance over their single channel counterparts in a multihop network.     

有界闭域上的线性赋值循环终止性分析

对有界闭域上的线性赋值循环程序终止性问题进行研究.利用Jordan 标准型技术将原循环程序的终止性问题约减为终止性等价的具有简单结构的循环程序的终止性问题.证明了当线性迭代映射满足一定条件时,该类循环程序不可终止的充分必要条件是：迭代映射在有界闭域上有不动点或周期轨.     

Subscription-free Pay-TV over IPTV

We propose a novel short-interval charging model for pay-TV over IPTV. To realize this model we develop an approach that relies on the channel switching action of users to trigger the charging process. When a user switches to a paid channel a multicast rekeying procedure is triggered resulting in a new content key for all viewing users of that paid channel. At this time the charging interval for the user who switched to the paid channel is started. In contrast, when a user leaves a paid channel, another multicast rekeying procedure is triggered resulting in a new content key for all viewing users of that paid channel except for the leaving user. At this time the charging interval for the user who left the paid channel is stopped. Obviously, this approach poses tight real-time requirements on the system. We designed and implemented this system based on an in-depth requirement analysis. The system test has shown that the proposed short-interval charging model is feasible without considerable violation of reported requirements regarding channel switching times.     

环上线性有限自动机的可逆性的一些结果

本文证明了有单位元的有限交换环R上任何延迟t步(弱)可逆线性有限自动机皆有延迟t步线性(弱)逆的充分必要条件是环R满足条件: x(Ax=0→bx=0)→y(b=yA)我们还证明了对任何有单有限交换环R,R上输入、输出维数相同的延迟t步(弱)可逆线性有限自动机具有延迟t步线性(弱)逆.     

Streaming video over variable bit-rate wireless channels

We consider streaming of video sequences over both constant and variable bit-rate (VBR) channels. Our goal is to enable decoding of each video unit before exceeding its displaying deadline and, hence, to guarantee successful sequence presentation even if the media rate does not match the channel rate. In this work, we show that the separation between a delay jitter buffer and a decoder buffer is in general suboptimal for VBR video transmitted over VBR channels. We specify the minimum initial delay and the minimum required buffer for a given video stream and a deterministic VBR channel. In addition, we provide some probabilistic statements in case that we observe a random behavior of the channel bit rate. A specific example tailored to wireless video streaming is discussed in greater detail and bounds are derived which allow guaranteeing a certain quality-of-service even for random VBR channels in a wireless environment. Simulation results validate the findings.     

Linear quadratic gaussian optimization approach for signal-to-noise ratio constrained control over network

The research area of control over networks has attracted great interest in recent years. Inserted in this research area is the study of control feedback limitations imposed by the presence of a communication channel. In this paper we analyze the fundamental limitations in control feedback stabilizability imposed by a class of Signal-to-Noise Ratio (SNR) constrained communication channels. We solve the SNR constrained control over network problem as a linear quadratic Gaussian (LQG) optimization with loop transfer recovery (LTR). If the communication channel is located on the feedback path then the LTR is said to be performed at the output. Vice versa, if the communication channel is on the control path, then the recovery is said to be performed at the input. In the present paper we address both cases, namely the LQG optimization with LTR at the output and the LQG optimization with LTR at the input to solve an LTI SNR constrained problem. We then explore the link between these two solutions.