语义客观报文生成方法及干扰效果评估系统

分析了在通信对抗试验训练中,基于语义的客观报文与传统报文之间的区别,给出了语义客观报文的优越性;介绍了语义客观报文的生成原理及其方法,提出了基于语义的客观报文干扰效果评估系统的构建方法.     

Minimum-energy broadcast and multicast in wireless networks: An integer programming approach and improved heuristic algorithms

Both integer programming models and heuristic algorithms have been proposed for finding minimum-energy broadcast and multicast trees in wireless ad hoc networks. Among heuristic algorithms, the broadcast/multicast incremental power (BIP/MIP) algorithm is most known. The theoretical performance of BIP/MIP has been quantified in several studies. To assess the empirical performance of BIP/MIP and other heuristic algorithms, it is necessary to compute an optimal tree or a very good lower bound of the optimum. In this paper, we present an integer programming approach as well as improved heuristic algorithms. Our integer programming approach comprises a novel integer model and a relaxation scheme. Unlike previously proposed models, the continuous relaxation of our model leads to a very sharp lower bound of the optimum. Our relaxation scheme allows for performance evaluation of heuristics without having to compute optimal trees. Our contributions to heuristic algorithms consist of the power-improving algorithm successive power adjustment (SPA), and improved time complexity of some previously suggested algorithms. We report extensive numerical experiments. Algorithm SPA finds better solutions in comparison to a host of other algorithms. Moreover, the integer programming approach shows that trees found by algorithm SPA are optimal or near-optimal.     

交互性纹理合成

扩充了Efros与Freeman的图片缝合算法,添加了图形用户界面,从而可以动态地改交参数,并对算法做了一些改进,增强了用户对纹理合成的可控性并丰富了合成纹理的多样性.     

Ad hoc路由协议性能评价

在继承传统路由协议性能评价的基础上,提出了较为清晰合理的Adhoc网络路由协议性能评价标准,并对Adhoc两种较为典型的路由协议DSDV、AODV进行仿真及性能分析.仿真结果表明AODV的稳定性要好于DSDV,但在网络拓扑变化缓慢的环境中,DSDV的分组时延较短.     

自整定模糊—PID在逆变电源系统中的应用

逆变电源系统结构特殊且具有较强的非线性和参数时变性,尤其在非线性负载下采用常规控制难以获得理想的控制效果。文章提出了自整定模糊—PID控制方案,该方案将模糊控制与PID控制的优势相结合,实时对PID参数进行在线调整。通过Matlab/Simulink对系统进行了仿真和验证,并与常规PID控制结果进行了对比和分析。     

10kV配电变压器状态评估模型研究

本文针对10kV配电变压器状态评估模型进行了介绍,叙述了变压器状态评级、评估指标体系的建立、评估模型的建立和实例计算等思路和方法。鉴于检修体制是否合理完善直接影响配电变压器可靠性水平,通过基于风险度计算的状态评估模型,对配电变压器进行状态评价,对变压器的合理使用和维修、故障预测以及配电管理等有着极为重要的意义。     

基于GPS和TTS的自动报站器方案设计

针对国内公交车报站器的应用现状,提出了一种基于GPS和TTS的全自动公交语音报站器的设计方案.分析了该报站器的特点并提出了其整体构架以及具体的终端设计,采用以ARM Cortex-M3为核心的stm32f103vet6处理器,通过GPS和GPRS相结合的方式实现车辆位置信息的读取、车辆与控制中心的无线通信,同时采用语音合成技术真正实现全自动准确地播报站名及服务提示信息.     

基于改进加权引导滤波的红外图像增强算法

针对红外图像对比度低、细节不清晰等问题,提出一种基于改进加权引导滤波的红外图像增强算法.首先将原图与梯度图叠加构建引导图像;其次利用canny算子修正边缘权重因子实现保边滤波;然后依据模糊理论设计模糊集增强算法增强图像细节信息;最后应用BM3 D去除图像噪声,得到最终增强图像.经对比实验验证,该算法可以有效地提升图像对...     

LiAl_(0.03)Mn_(1.97)O_4的流变相辅助微波合成及电化学性能

采用流变相辅助微波合成法,制备了结晶度好、纯度高的尖晶石相的锂离子电池正极材料LiAl0.03Mn1.97O4。对其进行了XRD分析和SEM研究,并与传统固相法制备的LiMn2O4和LiAl0.03Mn1.97O4进行了比较。结果表明,该合成法制备的LiAl0.03Mn1.97O4具有优良的电化学性能,用这种材料制造的电池具有比较高的首次放电容量(115 mAh/g)以及良好的可逆性和循环性能,25次循环后比容量几乎不变,保持在115 mAh/g左右。     

Solution-Chemical Syntheses of Nano-Structured Bi<Subscript>2</Subscript>Te<Subscript>3</Subscript> and PbTe Thermoelectric Materials

In this work, nano-structured Bi₂Te₃ and PbTe thermoelectric materials were synthesized separately via solvothermal, hydrothermal and low-temperature aqueous chemical routes. X-ray diffraction (XRD), field-emission scanning-electron microscopy (FESEM), transmission electron microscopy (TEM), and energy dispersive spectroscopy (EDS) were used to analyze the powder products. Results showed that the as-prepared Bi₂Te₃ samples were all single-phased and consisted of irregular spherical granules with diameters of ∼30 nm whereas the PbTe samples were mainly composed of well-crystallized cubic crystals with average size of approximately 100 nm. Some nanotubes and nanorods were found in Bi₂Te₃ and PbTe samples, respectively; these were identified as Bi₂Te₃ nanotubes and PbTe nanorods by EDS analysis. Possible reaction mechanisms for these syntheses are discussed in detail herein.