CPM信号相干解调的神经网络方法研究

本文研究连续相位调制信号相干解调的神经网络方法，提出了基于判决反馈预处理和变换域特征提取的射基函数网络解调方案。通过判决反馈预处理可以有效地减少网络输入信号样本个数，使其具有更好的可分性。利用高采样率下ＣＰＭ信号的相关性，引入变换域的处理方法可以大幅度地降低网络输入信号和样本空间维数。采用射基函数网络作为判决分类器，不仅可以逼近最大似然解调性能，而且无需加噪训练。模拟结果表明：本文提出的方案在降低训练及实现复杂度的同时具有接近最优的误比特性能     

Bidirectional NDVI and atmospherically resistant BRDF inversion for vegetation canopy

The normalized difference vegetation index (NDVI) has been widely applied in optical remote sensing. However, it has been demonstrated that NDVI is still partially affected by atmospheric path scattering and bidirectional (illumination and viewing geometry) effects. In this paper we present the benefit of using a bidirectional NDVI, and we discuss the problems in using the maximum NDVI composite method. Based on the assumption that a clear day has a larger NDVI value and a cloudy day has a smaller NDVI value (smaller reflectance in the near-infrared band and larger reflectance in red band due to atmospheric path scattering), the ratio of squared observed NDVI values and calculated NDVI values is used as a weight in our inversion method. The calculated NDVI values are derived from previously inverted bidirectional reflectance distribution functions (BRDFs). The inversion process will loop until all weights converge. Our research on the early Terra/MODIS data using a semiempirical kernel-driven BRDF model (the RossThick-LiTransit model) shows that this new method can improve inversion results whenever some cloudy pixels are not filtered out. As cloud detection and subpixel cloudiness are always a problem, this technique should still be very useful in improving the quality of BRDF inversion.     

Turbo乘积码在Rayleigh信道下的性能研究

Turbo乘积码（TPC）自从被提出以来表现出了优异的性能。研究了利用扩展汉明码作为其子码的TPC在Rayleigh信道下的性能．给出了不同的子码以及不同的迭代次数下的性能曲线,仿真结果表明了TPC在Rayleigh信道中同样有较强的纠错能力。     

系统级封装技术及其应用

本文介绍了系统级封装技术及其兴起背景,对比了与SoC的异同。通过分析系统级封装的技术特点,阐述了其优势;分析了系统级封装的成本构成和特点。本文从集成电路产业链整合的观点,分析了国内系统级封装的机遇与挑战;以长电科技为例,介绍了系统级封装在设计、制造上的关键技术与当前的能力,并分析了未来的趋势和挑战。本丈还对当前的系统级封装产品与应用领域做了详细介绍。     

A Model Reduction Perspective on Thermal Models for Induction Machine Overload Relays

Full-order thermal models are often used by machine designers to analyze the induction machine thermal behavior. The real-time implementation of such models for the purpose of motor thermal protection is difficult because an extensive knowledge on motors and sufficient computational resource are required. This paper demonstrates that full-order thermal models can be systematically reduced via pole-zero cancellation or Hankel singular-values-based model reduction techniques without additional physical assumptions. As a result, a system of a substantially lower dimension, which has nearly the same response characteristics in the frequency band of interest, is obtained. Both the estimated rotor cage temperature, which is extracted from the voltage and current measurements by a sensorless rotor temperature estimator, and the measured stator winding temperature are used to evaluate the performance of low-order thermal models. Given a certain tolerance for the modeling error, a reduced low-order thermal model can be used to characterize the thermal dynamics of a small- to medium-sized line-connected induction machine and to provide proper protection against motor overheating.     

改善经编复合灯箱布横向模量的研究

分析了导致经编复合灯箱布的衬纬纱屈曲的原因,通过改变骨架织物结构和与ＰＶＣ热粘合过程提高灯箱布的横向模量,从而改善国产灯箱布的使用质量。     

Bi2SiO5 Doping Concentration Effects on the Electrical Properties of SrBi2Ta2O9 Films

In this paper, we investigated the microstructure and electrical properties of Bi₂SiO₅ (BSO) doped SrBi₂Ta₂O₉ (SBT) films deposited by chemical solution deposition. X-ray diffraction observation indicated that the crystalline structures of all the BSO-doped SBT films are nearly the same as those of a pure SBT film. Through BSO doping, the 2Pr and 2Ec values of SBT films were changed from 15.3 μC/cm² and 138 kV/cm of pure SBT to 1.45 μC/cm² and 74 kV/cm of 10 wt.% BSO-doped SBT. The dielectric constant at 1 MHz for SBT varied from 199 of pure SBT to 96 of 10 wt.% BSO-doped SBT. The doped SBT films exhibited higher leakage current than that of non-doped SBT films. Nevertheless, all the doped SBT films still had small dielectric loss and low leakage current. Our present work will provide useful insights into the BSO doping effects to the SBT films, and it will be helpful for the material design in the future nonvolatile ferroelectric memories.     

二滩水电站地下厂房洞室的施工特点

国际承包商在二滩工程中的许多施工布置和方法，施工技术和工艺、施工设备和措施很具有特色，扩展了我们的视野、丰富的我们的思路。总结其经验，可作为国内类似工程的参考。     

高压变电站无线测温预警系统的设计

在高压变电站中,由于设备老化以及输变线路的接头温度过高,常常会引发火灾或者爆炸等事故。传统的人工温度测量不仅劳动强度大,而且容易出现漏测、误报等现象,无法实现对高压变电站的有效保护。因此,本文将无线通讯技术引入到高压变电站的温度测量当中,重点对无线测温预警系统进行分析,试图为之提供行之有效的可行性建议。     

大、中型地下车库智能寻车系统

为了提高停车场的服务水平,停车场智能管理系统是必不可少的.它已经在大部分停车场发挥着重要作用,在为人们停车带来方便的同时也具有良好的社会效益和经济效益.在大、中型地下车库中,车主返回停车场时,由于停车场太大或者地形不熟,车主容易找不到车,故提出了智能反向寻车系统.该系统可以帮助车主尽快找到车辆停放的区域,提高车主的满意...