数字图像远程监控系统的组网方式

本文阐述了数字图像远程监控系统在不同的传输介质中的组网方式,并详尽讨论了工程实现等问题。     

远程数字图像监控系统

主要介绍远程数字图像监控系统的组成、系统设备及指标、专网传输方案、IP传输方案及网络组成等内容。     

视频远程监控系统的组网方法

视频监控系统在国民经济、社会生活和航天发射等许多领域得到了广泛应用,已经成为现代管理、监测和控制的重要手段之一。视频监控系统能实时、形象、真实地反映被监控对像,长时间获取被监控对象的信息,极大地提高管理效率和自动化水平。尤其在一些危险性大、人不可直接观察或者不易直接观察的特殊场合,视频监控系统作为一种有效的观测手段发挥了不可替代的作用。例如,在进行航天发射试验时,距离发射架１５００ｍ的危险范围内,不允许人扛摄像机对飞行目标进行监控,这时远程视频监控就发挥着关键性的作用。如果要对发射进行现场直播,…     

数字图像远程集中监控系统设计

随着网络技术、通信技术以及视频点插技术的发展与成熟，数字图像远程集中监控系统将是继Internet之后的亲一轮信息高速公路的应用主流。本主要介绍了数字图像远程集中监控系统的组成、工作原理以及应用前景。     

朗讯DACS II和华为BITS本地远程集中监控系统的开发

首先简单介绍了朗讯DACSII和华为BITS本地远程集中监控系统的原理,然后分析了组网方式和设备型号的选择,在此基础上详细地介绍了具体的实现方式.     

数字图像远程集中监控系统设计

数字图像远程集中监控系统是一各全新的交互式多媒体监控系统,是结合先进的计算机网络技术、多媒体技术、通信技术、适应电信、电力、银行、交通、水利以及公安等行业用户多样化需求的数字科像监控系统的建设方案。随着网络技术、通信技术以及视频点播技术的发展与成熟。将得到广泛应用。     

朗讯DACSⅡ和华为BITS本地远程集中监控系统的开发

首先简单介绍了朗讯DACSⅡ和华为BITS本地远程集中监控系统的原理，然后分析了组网方式和设备型号的选择，在此基础上详细地介绍了具体的实现方式。     

广播电视发射台远程监控系统设计

随着技术的进步,特别是远程监控技术的不断发展,对广播电视发射台实施远程监控已成为提高运维效率、确保传输质量的重要手段。设计一套远程监控系统,以提升广播电视发射台的管理效率和服务质量。阐述系统的总体结构设计,深入分析系统的软件结构和数据库设计,旨在为广播电视发射台的远程监控系统设计提供理论和实践指导,为类似领域的系统设计提供参考。     

分布式数字图像监控系统

阐述分布式多点静态实体防护数字图像监视系统的概念模型和相关实现技术     

安徽水利远程视频监控系统组网方案

安徽水利远程视频监控系统采用硬件编码器和TCP／IP协议组网，依靠已建的防汛抗旱通信骨干网并利用多业务交换平台对电路带宽按需分配的特性，实现高清晰、实时图像的远程传输和控制，取得了良好的组网效果。本工程组网方案可作为类似工程建设的参考。[编者按]     

高速网络互连技术探析

主要讨论了几种高速网络互连技术的特点、发展情况、概述，并对未来网络互连的发展方向做了深入的分析。     

基于数字图像处理算法的皮肤测试仪

详细介绍了基于数字图像处理算法的皮肤测试仪的设计过程.该皮肤测试仪以台湾义统公司的ET44M210作为MCU实现对整个系统的控制;以台湾义统公司的ET21X130B模块作为影像传感器,实现肤质图像数据的实时采集;通过PC中数字图像处理算法软件对肤质的重要参数进行分析比对.实践表明,该皮肤测试仪十分适合家庭及爱美人士作为便携式皮肤测试仪使用.     

Ku-band satellite digital transmission systems

A nation-wide data communications service is being placed in service by a major telecommunications carrier. This service will rely on a satellite network being provided and installed by Harris Satellite Communications Corporation. The network supports information data rates from 56 kb/s to 2·048 Mb/s. This data communications network has been architectured to include a number of innovative monitor and control functions, up-link power control, modular equipment shelter design and a modular antenna/feed subsystem. This paper will detail this application.     

Flexible regenerator for digital transmission systems

The concept of a flexible regenerator employing multiple frequency timing recovery is presented. Results are given for two possible types of multiple passband timing recovery filters?narrowband-narrowband and narrowband-wideband. In both cases, results show that the regenerator can be retimed using either passband without significant degradation due to the proximity and bandwidth of the redundant passband.     

便携式数字图像微波中继传输的设计

图像信息因其直观、生动、信息量大而获得了广泛应用,图像的处理与传输成为一个重要的研究课题。设计了一种适于野外使用的图像数字化微波再生中继传输系统,叙述了该系统的组成与工作原理,给出了试验结果和应用范围。     

Estimation of the reliability of digital systems implemented on programmable devices

In this paper, the authors propose to use the functional reliability parameters as a criterion for consistent choice of a project solution on the basis of the forecast reliability parameters. The authors take into account the failures as the main reason of incorrect performance of the designed digital systems, implemented on programmable devices. The electromagnetic parasitic noises arising in the microelectronics chip is one of the main reason of failure occurrences. Their influence on the reliability parameters of the designed project has been determined. Mathematical models (MM) of internal noises have been developed. On the basis of these MM and with the noise immunity margin as well, the developer is able to estimate the functional reliability parameters of logic gate at single switching. The received evaluations of the failure probabilities are accepted as the basic characteristics and are used hereinafter when evaluating the probability of correct functioning of a designed project.The obtained reliability parameters permit the developer to choose the optimal architecture of the designed project by comparing the alternative variants. For practical realization of the proposed approach, the software subsystem “FunNad-2” has been developed.     

Vectored transmission for digital subscriber line systems

This paper describes the "vectored" transmission technique for digital subscriber line (DSL) systems, which utilizes user coordination at the central office or optical network unit. This method exploits the colocation of the downstream transmitters and of the upstream receivers, in order to achieve far-end crosstalk (FEXT) cancellation and perform multiuser transmission optimization. The performance improvements are particularly pronounced in environments with strong FEXT such as in very high-speed DSL. Discrete multitone is employed for each user with additional constraints on the cyclic prefix length and with the assumption of block-synchronized transmission and reception for downstream and upstream transmission correspondingly. Within each tone, upstream crosstalk is removed by multiple-input-multiple-output decision feedback at the receiving side, while downstream crosstalk is eliminated by analogous preprocessing at the transmitting side. Additionally, the issue of transmission energy allocation in frequency and among users is addressed. Assuming frequency-division duplexing, the corresponding optimization problem is formulated and solved via convex programming both for a fixed upstream-downstream band plan and for a dynamically programmable band plan. The case of power backoff as a means to reduce the impact of crosstalk on alien systems is also treated. Interestingly, the performance of the proposed methods is shown to be very close to known information theory bounds     

Performance characterization of digital transmission systems withcochannel interference

This paper presents a general methodology for performance characterization of digital transmission systems in the presence of cochannel interference, as a function of the actual number of interferers (ranging from zero to infinity). The bit error probability in time-invariant channels and outage probability in time-varying quasi-stationary channels are discussed. More precisely, a general approach to an outage probability definition based on the concept of the outage domain is introduced. This allows the discussion of the relation to the other definitions which have appeared in the literature and the proposal of some new more accurate methods for the evaluation of outage probability. A suitable comparison between exact evaluation, the well-known Gaussian approximation, and the other new approaches proposed in this paper, is carried out to evaluate performance, bit error probability is suitably obtained for linearly modulated signals by adopting a semianalytical approach, and for nonlinear (e.g., continuous phase) modulation signals, by means of simulation. Finally, as an example, the different approaches to derive performance discussed in the paper have been applied to a linear microcellular scenario     

Synchronous digital transmission systems based on CCITT SDHstandard

The synchronous digital hierarchy (SDH) transmission systems developed by NTT are discussed. The advantages of SDH are detailed, stressing its simplified network structure and enhanced operations, administration, and maintenance functions. The layered architecture of the SDH systems is described. NTT's SDH fiber-optic transmission systems and digital radio transmission systems are presented     

Expressions for the analysis of digital transmission systems

It is shown that, if the sinusoidal roll-off response commonly used in the analysis of digital transmission systmes is replaced by a trapezoidal response, it is possible to derive algebraic expressions for the signal/noise ratio and error rate in cases of practical importance.