Fast-response storage-type solar cooker

All the solar powered cookers presently available in the world market are of the so-called “Reflector Box” type. Despite the fact that they have been presented, for a good few years, to the market and are very simple and low cost they have not managed to establish any meaningful and noticeable presence in a viable commercial sense. This fact is even more in evidence in those markets they are primarily designed for. The reasons to the lack of commercial success for the reflector box type cookers are analysed in some details. The assessment of general features and performance of the reflector box type cooker led to the design of the Fast Response Storage Type Cooker presented in this paper.The new cooker is the result of combination of non-tracking compound parabolic reflector, fast response heat pipes, high-quality and low-cost thermal insulator, low-loss thermal storage battery, glass to metal seals, vacuum technology and bimetal automatic switches. It is capable of storing the solar energy during the day to facilitate cooking during the evenings and nights. A prototype is made and the performance of the elements of the system are presented. It shows how the “waste-energy” of the cooker can be used for other applications.     

基于线阵的多波束比幅法圆锥误差分析

在一维线阵条件下,利用多波束比幅法测量方位角时,随着入射信号仰角变大,方位角测量误差会变大。分析了不同仰角下的波束偏离,提出了利用“修正角度”减小圆锥误差的方法,并比较修正前后测量误差统计值,说明达到了提高方位角测量精度的效果。     

LED显示屏质量提升的探讨

近年来LED显示屏被广泛应用于室内外显示领域。文章主要依据信息产业部标准SJ/T11141-2003《LED显示屏通用规范》和SJ/T11281-2007《发光二极管（LED）显示屏测试方法》,针对LED显示屏的一些重要考核指标如亮度、均匀性、视角和安全等,探讨如何提升LED显示屏的质量。     

半导体激光器远场发散角的近似计算

从半导体激光器的单模工作条件出发,提出一个远场发散角的近似公式。比较用此近似公式计算结果与数值计算、二阶矩近似计算的结果发现,在半导体实际应用中的波导层范围,该公式能减少计算难度,同时能够满足精度要求。     

无刷双馈电机的稳态转矩-角特性

简述了从无刷双馈电机的电机变量的方程推导无刷双馈电机的双轴数学模型,在双轴模型的基础上,仿真研究了稳态运行时ｄ－ｑ模型下功率绕组与控制绕组间电压相角差与电机电磁转矩的关系,揭示了无刷双馈电机稳态运行时具有同步电机特性,并为该电机运行状态的控制提供了依据。     

具有控制约束的最速驾驶仪设计

为了解决导弹控制系统设计过程中采用试凑法进行参数设计周期太长以及执行机构饱和约束不易加入的问题．提出一种建模思想。将控制系统设计问题变为有约束优化问题。把系统的性能指标和执行机构饱和约束转化为约束条件。上升时间作为目标函数．采用逐次逼近法来进行迭代，直到得到满足约束的控制器参数。此方法能够直观地引入各种约束。并能够有效缩短导弹控制系统设计周期。     

抛光型SLAM系统灵敏度研究

以片式电子材料元器件作为无损检测分析对象,以提高激光扫描声学显微镜(SLAM)系统灵敏度为目标,详细分析了入射声波在抛光型分层介质中的传播规律,建立了抛光型样品自由界面动态波纹振幅数学模型。经综合分析获得了提高系统响应的方法,为进一步改进SLAM提供了理论依据。     

A joint TDOA and FDOA estimation algorithm based on second-order cone programming

ABSTRACT

Considering the low estimation accuracy of the traditional interpolation method, this paper, on the basis of second-order cone programming (SOCP), proposes a novel joint time difference of arrival (TDOA) and frequency difference of arrival (FDOA) estimation interpolation method, which can attain the sub-sample precision. The proposed method uses several discrete samples produced by cross ambiguity function (CAF) to structure the convex optimization models with regard to the interpolation surface. Then, the SOCP is utilized to obtain the interpolation surface which matches the discrete surface of CAF well. Finally, the method achieves the precision superior to the traditional TDOA and FDOA estimation directly through the search for the maximum of the continuous approximate surface. This method decreases the computational load without loss of precision and can efficiently reduce the limitation of finite sampling interval and sampling time in estimation precision. Numerical simulations show that the method in this paper is efficient and outperforms existing interpolation algorithms about estimation precision.     

一种激光导引头角跟踪回路的建模与仿真

讨论考虑激光探测非线性和脉冲重复频率等因素时,激光导引头角跟踪回路的数学模型,并在MATLAB下对该模型进行仿真。以满足导引头的性能指标为前提,优选系统结构参数,分析系统特性。     

TD-LTE双频网结构规划研究

本文分析了TD-LTE系统F/D双频组网的必要性;分析了TD-LTE系统F/D双频组网的难点;分析了网络结构的调整对双频组网带来的影响;结合实际网络测试结果提出了合理的网络结构规划方案。