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LIU Gang GOU Dingyong WU Shiqi 《中国电子科技》2003,1(1)
A new handover strategy named minimal-hops handover(MHH) strategy for the lowearth orbit(LEO) satellite constellations networks equipped with inter-satellite links(ISLs) is proposed.MHH strategy,which is based on the hops of the end-to-end connection paths and makes good use of theregularity of the constellation network topology,can appropriately combine the handover procedure withrouting and efficiently solve the inter-satellite handover issue.Moreover,MHH strategy can providequality of services(QoS) guarantees to some extent.The system performances of the MHH strategy,suchas time propagation delay and handover frequency,are evaluated and compared with that of otherprevious strategies.The simulation results show that MHH strategy performs better than other previoushandover strategies. 相似文献
24.
蒋盘林 《电子信息对抗技术》2009,24(5):40-46
面对当今世界军事变革、部队转型的新形势,我们必须深刻思考军事战略重心转移所引发的需求变化以及新的武器装备采办政策、技术发展路线图等等问题。从电子信息对抗在未来战争中的作用和地位出发,分析其主体作战对象的发展特点,并根据未来电子信息对抗核心作战能力建设的军事需求,探讨能够确保全谱战斗空间信息优势和决策优势的对抗体系及其发展战略。 相似文献
25.
在分析LEO卫星星座移动通信系统空间段网络功能和特点的基础上,进行了星座网络路由和交换技术体制的分析和论证,提出了以支持话音业务为主的LEO卫星移动通信系统星座网络路由和交换技术方案。星座网络采用定长信元格式交换体制,采用动态拓扑离散化的拓扑快照静态路由策略。这种静态路由离线计算方式和定长信元交换相结合,提高了网络交换的效率和转发速率。 相似文献
26.
A spectrally‐efficient scheme is proposed for orthogonal decode‐and‐forward relaying. By utilizing constellation rotation, the scheme can achieve twice the spectral efficiency as that of the conventional one, with low implementation complexity. It can offer a full diversity order as well, whereas the loss in coding gain is less than 1 dB for practical environments. 相似文献
27.
We systematically investigate the motion of slowly moving
matter--wave gap solitons in a nonlinear potential, produced by the
weak random spatial variation of the atomic scattering length. With
the weak randomness, we construct an effective-particle theory to
study the motion of gap solitons. Based on the effective-particle
theory, the effect of the randomness on gap solitons is obtained, and
the motion of gap solitons is finally solved. Moreover, the analytic
results for the general behaviours of gap soliton motion, such as the
ensemble-average speed and the reflection probability depending on
the weak randomness are obtained. We find that with the increase of
the random strength the ensemble-average speed of gap solitons
decreases slowly where the reduction is proportional to the variance
of the weak randomness, and the reflection probability becomes
larger. The theoretical results are in good agreement with the
numerical simulations based on the Gross--Pitaevskii equation. 相似文献
28.
加热炉炉管的红外热像监测方法研究 总被引:1,自引:1,他引:0
文中所介绍的乃是获奖项目“高温炉管的红外在线监测诊断及评估系统研究”科研成
果的一部分。试验研究结果表明,在进口的如PM350 类焦平面红外热像仪的基础上,合理地选装高温火焰滤片、广角镜头以及红外隔热罩,便可实现通过看火孔对加热炉炉管进行红外热像的在线监测。而通过试验研究所得到的误差修正方法,可以使炉管的红外热像监测结果与接触式的热电偶测试结果相差小于2 %。现场工业试验的结果表明,该方法完全满足了生产装置监测的需要。 相似文献
29.
巧用Word绘制有线电视图纸 总被引:1,自引:0,他引:1
给Word的工具栏中添加“有线电视”专用绘图工具栏,充分开发Word的图文编辑功能,实现有线电视设备或其他元器件单元图形的即点即输,可非常方便地编辑出图文并茂的有线电视专业文稿。 相似文献
30.
This is the second of two papers in which we study real and virtual photon-proton scattering in a nonperturbative framework. In the first paper we have identified the leading contributions to this process at high energies and have derived expressions for them which take into account the renormalisation of the photon-quark-antiquark vertex. In the present paper we investigate the approximations and assumptions that are necessary to obtain the dipole model of high energy scattering from the results derived in the first paper. We discuss the gauge invariance of different contributions to the scattering amplitude and point out some subtleties related to gauge invariance in the correct definition of a perturbative photon wave function. As a phenomenological consequence of the dipole picture we derive a bound on the ratio of the cross sections for longitudinally and transversely polarised photons. This bound is independent of any particular model for the dipole-proton cross section and allows one to test the validity of the assumptions leading to the dipole picture in particular at low photon virtualities. We conclude that the naive dipole model formula should be supplemented by two additional terms which can potentially become large at small photon virtualities. 相似文献