通信市场又遇新军 诺达公司登陆中国

德国诺达卫星通信公司在京设立中国代表处 欧洲领先的卫星通信网络和地面站系统提供商德国诺达卫星通信公司(ND SatCom)于2003年3月20日在京宣布设立中国代表处。 德国诺达卫星通信公司中国首席代表舒华先生介绍:自1997年在新加坡(Singapore)设立办事处以来,NI)SatCom 开始进入亚洲市场,至今已在新加坡、新德里(New Delhi)、雅加达(Jakarta)与北京开设了四个销售和服     

德国诺达:用户长期的伙伴和永远的朋友--访诺达公司首席执行官格拉森博士一行

德国诺达卫星通信公司虽然在2003年才在北京正式设立了代表处，但实际上早在三年前就已经进入中国市场，并小有成效，开拓出了一方明亮的天空。在诺达公司为庆祝代表处正式成立而举办的酒会前一小时，记者在嘉里中心“炫酷吧”一间不大的房间里，对诺达公司首席执行官格拉森博士一行进行了简短的采访。     

德国诺达卫星通信植根中国

2006年1月20日下午,德国诺达卫星通信公司(ND SatCom AG)在北京举行了其中国公司成立新闻发布会。诺达公司总裁兼首席执行官卡尔·克拉森博士(Dr．Karl Classen)、公司副总裁兼中国区董事总经理叶朋博士以及公司北京代表处首席代表舒华先生出席了发布会。     

国外海军卫星通信的发展

本文主要分析介绍国外海军卫星通信技术的应用和发展。在概述基本情况的基础上，分别介绍了国外海军卫星通信的空间部分－通信卫星和舰载卫星通信终端；并阐述了国外舰船卫星通信的主要技术政策。     

ND5机车故障励磁系统数据采集模块的抗干扰设计

介绍了ND5内燃机车在强电磁干扰的环境下,通过采取多种电路抗干扰措施,如接地合理安排和光耦合器隔离技术,有效地抑制EMI（电磁干扰）对数据采集模块的干扰。机车的励磁系统根据数据采集模块提供的准确、可靠的数据,给出控制和保护信号。在此基础上,全程记录机车数据,为技术人员事后分析故障、消除励磁系统存在的隐患提供了技术依据。经过近2年的运行,大大地改善了ND5机车原系统存在的缺陷,从而保证机车励磁系统正常可靠地工作,更好地充分发挥ND5机车的工作效率。     

A tensor decomposition approach to data compression and approximation of ND systems

The method of Proper Orthogonal Decompositions (POD) is a data-based method that is suitable for the reduction of large-scale distributed systems. In this paper we propose a generalization of the POD method so as to take the ND nature of a distributed model into account. This results in a novel procedure for model reduction of systems with multiple independent variables. Data in multiple independent variables is associated with the mathematical structure of a tensor. We show how orthonormal decompositions of this tensor can be used to derive suitable projection spaces. These projection spaces prove useful for determining reduced order models by performing Galerkin projections on equation residuals. We demonstrate how prior knowledge about the structure of the model reduction problem can be used to improve the quality of approximations. The tensor decomposition techniques are demonstrated on an application in data compression. The proposed model reduction procedure is illustrated on a heat diffusion problem.     

New explanation of ND?1 dependence of specific contact resistance for n-GaAs

A new model of the ohmic contact to n-GaAs is proposed. It assumes that the contact resistance is due to the n+/n-barrier between the contact region (n+) and the semiconductor bulk (n = ND) as long as the bulk concentration is smaller than the effective density of states. Then the contact resistance is inversely proportional to the dopant concentration.     

Pulse compression inside an actively AM mode-locked ND:YAG laser using a liquid Kerr cell

A mode-locked Nd:YAG laser capable of generating pulses substantially shorter than the present limit of 30-50 ps, while retaining the stability of active mode locking, would be a useful development. We present here a simplified theoretical analysis and a preliminary experimental verification of the use of an optical Kerr cell as a passive lossless pulse compressor inside aQ-switched and actively mode-locked YAG laser. The theoretical model indicates possible compression to as short as ∼5 ps in a typical low-power Nd:YAG laser. The preliminary experimental results show substantial pulse compression via the predicted mechanism, though still not below ∼30 ps. The technique appears capable, however, of pulse compression to substantially shorter values without the instabilities, statistical fluctuations, or energy losses associated with saturable-absorber mode locking.     

ND:YAG light source and external modulator for a VSB-AM video transmitter: A performance evaluation

A miniature Nd:YAG laser and an intensity modulator based VSB-AM video signal transmitter are described. With a light source having RIN level below -170 dB/Hz, the system allows a relatively low modulation index to be used. For a 40 channel system using a standard MZ, a CTB = 60 dB corresponds to m_i = 1 per cent. With a 75 mW Nd:YAG laser source, a system with a power budget of 5.5 dB and 50 dB CNR is realizable. Several promising techniques of modulator linearization are also given.     

ND++ – an extended IPv6 Neighbor Discovery protocol for enhanced stateless address autoconfiguration in MANETs

Recent trends in information and communications technologies are oriented toward the design of the Future Internet and the Internet of Things. While IPv6‐based mobile ad hoc networks (MANETs) are emerging as an important building block of these new technologies, it is necessary to come up with adequate self‐configuration capabilities allowing for seamless and automated configuration of addresses in mobile environment. The mechanisms of stateless address autoconfiguration proposed for IPv6 networks are supposed to automate some configuration steps; however, they would need to be aligned with the requirements imposed by MANET networks. Therefore, in this article, we present Neighbor Discovery ++ – an extended IPv6 Neighbor Discovery protocol for enhanced duplicate address detection in MANETs, which provides increased coverage of network nodes, while minimizing protocol overhead. It exploits efficient flooding mechanism on the basis of the multipoint relay concept, which makes it an interesting approach also for large‐scale networks. Trials performed on the designated real‐world testbed platform indicate that ND++ is a promising solution to support efficient address autoconfiguration in MANETs. Copyright © 2012 John Wiley & Sons, Ltd.     

Electrical and reliability characteristics of an ultrathin TaO/sub x/N/sub y/ gate dielectric prepared by ND/sub 3/ annealing of Ta/sub 2/O/sub 5/

This letter describes a unique process for the preparation of high quality tantalum oxynitride (TaO/sub x/N/sub y/) via the ND/sub 3/ annealing of Ta/sub 2/O/sub 5/, for use in gate dielectric applications. Compared with tantalum oxide (Ta/sub 2/O/sub 5/), a significant improvement in the dielectric constant was obtained by the ammonia treatment followed by light reoxidation in a wet ambient. We were able to confirm nitrogen incorporation in the tantalum oxynitride (TaO/sub x/N/sub y/) by Auger electron spectroscopy. Compared with NH/sub 3/ nitridation, tantalum oxynitride prepared by nitridation in ND/sub 3/ shows less charge trapping and larger charge-to-breakdown characteristics.