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1.
近两年.IP电话又叫网络电话的发展受到全球的关注。随着宽带接入的发展,基于宽带接入提供的网络电话具有了更大的生命力。从宽带电话的经营模式出发,探究这类业务的出现时现有话音业务市场的影响,进而分析这类业务的发展前景。 相似文献
2.
本文全面介绍了我国跟踪智能网世界先进技术,研究开发自主产权的国产智能网情况,简述了国产主流产品CIN系列智能网产品产业化和应用情况,对国产智能网的发展应用和产业化提出了建议。 相似文献
3.
This paper presents the development of an optimization and a computer-simulation model to evaluate the process plans of a manufacturing center by analyzing the effect of tool failure on system performance. The GPSS/PC simulation program that is used in this study has been built with variables, functions and matrices so that many experiments could be conducted with the model. Sensitivity analysis is presented and the developed model has proven to be useful in determining optimum sequencing of parts for various operating policies. 相似文献
4.
Contributed by Ascom Timeplex Far East Ltd. 《世界电信》1994,7(2):21-24
亚洲电信业的市场正随着经济的蓬勃发展而迅速增大,然而大多数电信运营部门没能尽快更新设备以跟上商业需求增长的步伐。本文在分析用户业务需求的变化和对现有电信基础设施进行评估之后,提出应加强或采用叠加、并行的网络设施来为增长中的用户服务。同时认为通信资费应根据用户实际业务量的情况进行调整。这些做法将有助于电信经营部门处于更有竞争力的地位并从不断扩大的市场中赢得更多份额。 相似文献
5.
受中国电信委托、原邮电部经济技术发展研究中心在全国进行一次农村电信市场调查,以了解当前农村通信市场发展潜力,本文公布了此次调查的结果,从经济能力、资费和潜在市场等方面提出了发展农话的建议 。 相似文献
6.
A semi-Markov model is constructed that describes an arbitrarily structured multicomponent technological system and takes
into account its calendar maintenance. Using an aggregation algorithm, approximate values of stationary reliability characteristics
and an optimal term of maintenance work are determined for the system.
__________
Translated from Kibernetika i Sistemnyi Analiz, No. 2, pp. 69–86, March–April 2006. 相似文献
7.
Klaus G. Johannsen 《International Journal of Satellite Communications and Networking》1987,5(3):233-247
Several domestic satellite systems have been more than 10 years in operation. During this time, the world has experienced a dramatic growth in communication. While the demand for more telephony and data circuits and television channels is still on the rise, new methods of signal transmission and circuit compression have been developed which may balance or reduce the need for more satellite trunk capacity. And while whole national networks are converting to digital transmission, new transmission media like optical fibre, are finding application, and may take over some of the heavy traffic routes previously carried by satellite. On the other side, business data communication between roof-top terminals, thin route traffic to remote users, television distribution by direct satellite broadcasting are becoming more popular and satellite land mobile communication may soon be a reality. Thus the domestic satellite's role appears to be slowly changing towards thin route and mobile traffic and DBS-type distribution and perhaps even radio position determination. System planners are adapting to the new trends in satellite communication and are trying to accommodate the various service payloads on a single satellite. This article discusses some aspects of the emerging multi-purpose domestic satellite, which carries fixed and mobile services, TV direct broadcasting and radio position determination, in view of network digitalization, network expansion, circuit compression, synchronization. The discussion centres on transponder supply and demand, satellite replenishment, Ku-band vs. C-band for TV direct satellite broadcasting, choice of modulation/multiple access for mobile communication, and expected accuracy in radio position determination. 相似文献
8.
9.
The tendencies characterizing worsening of natural, mining and technical, as well as mining and geological conditions of deposit mining are analyzed for the last 100 years. The change in prices for mineral raw material is shown, and the influence exerted by scientific and technical progress in the sphere of mining and processing of copper-containing ores is established. An approach to the estimate of available mineral reserves and possibility of their involvement in mining is stated. 相似文献
10.
Rice husk generated as a by-product of rice processing is an important energy resource. The availability of this resource in India has been assessed and the technologies for exploitation of its energy potential in rice processing industry discussed. Nomographs have been developed for estimation of the husk required to meet the energy demand of parboiling, drying and milling operations. The unit cost of electricity using rice husk gasifier-based power generation systems has been calculated and its financial feasibility assessed in comparison with utility-supplied and diesel-generated electricity. With the cost and efficiency data assumed here, the unit cost of electricity produced by rice husk gasifier-dual fuel engine-generator system varies between Rs 2/kWh and Rs 7/kWh. (Note: 35 Rs approximates to $US 1.) 相似文献