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煤矿井下小灵通无线通讯系统优化 总被引:1,自引:0,他引:1
介绍了煤矿井下小灵通无线通讯系统网络结构和空中接口原理.针对小灵通在煤矿井下使用中存在掉话、切拱等问题,结合公网小灵通系统优化经验,提出适合煤矿井下环境的优化方法,这些优化方法从根本上解决了影响现场使用效果的问题,可综合运用于煤矿井下小灵通系统优化过程. 相似文献
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GNSS(Global Navigation Satellite System)欺骗干扰装备,是"导航战"重要组成,对其效能的有效评估决定了目标任务的成功.但目前存在影响因素的模糊性和不确定性大、因素间影响关系的传递性弱、评估方法适用性差、评估效率低等难点问题.针对这些问题,本文提出一种基于灰色关联分析和模糊综合评判的评估方法.在指标体系搭建完成的基础上,利用层次分析法确定指标权重,并通过纵向计算灰色关联度,得到最优方案;再通过模糊综合评判,得到最优方案的评估结果;最后通过横向计算灰色关联度,来选取与评估结果关联度高的指标.实验证明,本文提出的方法解决了评估存在的难点问题,达到有效评估的目的. 相似文献
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上海贝尔阿尔卡特传输网络事业部 《电信建设》2002,(4):41-41
城域综合业务传送网已成为当前各大运营商通信建设的重点领域.它的主要特点为:(1)提高网络带宽利用率和安全性;(2)提供开放、兼容和灵活的业务接口;(3)快速、低成本业务部署及增强综合管理能力.这些特点也正是现今城域综合业务传送网所要解决的核心问题. 相似文献
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叙述了公共广播声压级自动调节的工作原理,详细介绍了声压级自动调节的一些实现方法.这些方法有时需要综合运用才能取得较好的效果. 相似文献
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针对复杂电子设备整机级的结构有限元分析中出现的单元数量巨大,导致计算量大,模态分析和功率谱密度(PSD)分析难以完成的问题,采用子结构方法中的模态综合法简化有限元模型。该方法可以把大模型分为几个小模型来计算,使一般性能的计算机也可以分析较大规模的有限元模型;通过在某复杂电子设备的有限元分析过程中的应用,结果表明该方法计算结果准确,计算效率高,为复杂电子设备的结构有限元分析提供了一种有效解决方案。 相似文献
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樊德森 《电子科学学刊(英文版)》1992,9(3):253-260
A general analysis approach to multi-object(M-object)scattering systems of ar-bitrary structure is presented.Through the system scattering equation(SSE),the M-objectproblems are first transformed into a series of single-object(S-object)problems and then arethey solved,one-object by one-object,to determine the unknown coefficients of SSE.Finally theSSE is solved to yield the global solutions of original M-object problems.As to the solution ofS-object problems concerned,we use the global numerical boundary condition(GNBC)basedfinite element method(FEM)for complex scatterers,or the moment method(MM)for conduct-ing scatterers.For clarity we will confine ourself in two-dimensional(2-D)cases,and show somecalculation examples of M-object scattering systems for demonstration. 相似文献
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Bergamaschi R.A. Kuehlmann A. 《Very Large Scale Integration (VLSI) Systems, IEEE Transactions on》1993,1(3):233-243
High-level synthesis has been an active research field since the early eighties. However, apart from a few exceptions the technology has so far failed to make a smooth transition into the industrial environment. The main reasons are related more to the lack of an integrated methodology, including design entry, simulation, and synthesis, than to the quality of the synthesis algorithms. Experiences in applying the HIS system (High-level IBM Synthesis System) to real designs led to the development of a system and methodology which integrate language modeling, simulation, high-level, and logic synthesis. This paper presents the main concepts behind this system, namely, its modeling, synthesis, and simulation capabilities. Moreover, it addresses some of the problems encountered when transferring high-level synthesis to a production environment 相似文献
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S. E. Mishchenko 《Radioelectronics and Communications Systems》2007,50(9):516-523
The problem definition of general random geometry continuous and discontinuous antenna vector synthesis is discussed. Conditions are formulated which allow presenting the initial antenna vector synthesis problem in the form of array of some scalar synthesis problems while locating the antenna in the free space and near the surface. On plane, cylinder and sphere examples antenna synthesis problems division possibilities of scalar problems are examined. 相似文献
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在利用数值方法分析非均匀介质问题时,容易生成大型系数矩阵,从而在求解时常常造成计算机内存不足或者计算时间过长。该文利用区域分解方法对三维非均匀介质成像问题进行分析,通过将求解区域划分为几个子区域,在子区域上以迭代求解子问题的方式解决以上问题。文中给出的迭代收敛速度曲线证明区域分解算法的收敛速度很快。该文对一些复杂的非均匀介质问题给出了模拟测量成像的结果。 相似文献
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天基综合信息网是卫星通信与传统网络技术融合的必然发展趋势。文中首先介绍了天基综合信息网的组成和特点,然后分析了组建天基综合信息网存在的部分技术问题及天基网的安全问题,并给出了初步解决建议,最后对全文进行了总结。 相似文献
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本文提出一种多体散射系统的普遍化的分析方法,原则上能处理任意形式的多体散射系统。利用系统散射方程把多体问题归结为一组单体问题,然后用有限元法对各个单体问题逐个进行分析。本文着重讨论二维多体系统,并给出由介质涂敷导体往构成的三体散射系统的计算实例。 相似文献
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On the constrained synthesis of array patterns with applications to circular and arc arrays 总被引:1,自引:0,他引:1
Synthesis of array patterns involving optimization with linear and nonlinear constraints is considered. The general solution for the composite weight vector can be decomposed into a part which satisfies the linear constraints and another lying orthogonal to it. This decomposition is shown to yield simple solutions to several beam optimization problems including some with nonlinear constraints. A geometrical derivation of this result is presented which also provides new insights into the mechanism of null-steering via linear constraints. Application of this approach in conjunction with some search algorithms to the synthesis of optimum array patterns with prescribed narrow or broad nulls is shown to yield interesting and useful solutions. The results are illustrated by considering the design of "circular" and "arc" arrays. 相似文献