Motion compensation approach for airborne bistatic SAR imaging

In airborne bistatic synthetic aperture radar (BiSAR) imaging, not only the motion error of the airborne platform, but also the inaccuracy of data acquisition geometry will introduce an additional phase error that seriously degrades the focusing quality of the final image. For one-stationary BiSAR imaging, the influence of the inaccurate geometry is analyzed in detail and an applicable motion compensation approach is proposed. By using Doppler rates estimation, the phase error both from the motion error and the inaccurate geometry is appropriately compensated so that the focusing quality of the final image is consequently improved. Analyses of acquired raw data are presented to verify the proposal.     

220 kV CVT不拆线试验时电容值误差分析与计算

现场通过对一组220 kV CVT不拆线进行预防性试验,对用常规法测量C2时电容值误差的原因进行分析,得出的结果是由于不拆线进行试验,电容C11,C1的接入,使得标准臂的参数发生了变化。因此,220 kV CVT按常规办法读取C2电容量后,必须乘以系数0.56才是电容C2的实际值。     

Mobility aided localization of wireless sensor networks with inaccurate range measurements

This paper studies the relationship between mobility, navigation and localization in the context of wireless sensor networks with mobile beacons. It is observed that mobility can aid in network node localization and that once localized, the network nodes can localize and track a mobile object and guide its navigation. A distributed kernel-based algorithm is proposed that enables the nodes to establish confident position estimates in the presence of ranging inaccuracies. The proposed approach features robustness with respect to range measurement inaccuracies, low complexity and distributed implementation, using only local information. Simulation validates our approach viable.     

轨道轮外形测量仪的研究

为了填补我国轨道轮踏面外形测量的空白,研制了一种便携式的轨道轮踏面外形测量仪.该装置由测量部分和手持PDA组成.测量机构测量过程中,编码器采集数据,并通过蓝牙发送给PDA进行数据处理及显示.无线传输,用手持PDA代替电脑处理数据.给出了测量原理,仿真了不同踏面对测量机构参数选择的影响,并对测量模型的原理误差进行了分析.     

影响实用化实时测温系统测温精度的几个因素

基于Kirchhoff定律,利用半导体激光器及钽酸锂热释电探测器设计了一种实用化的实时测温系统,从待测目标表面的红外辐射特性、待测表面周围的其它辐射体、大气的透射特性以及测温系统本身这四个方面出发,对影响该系统测温精度的因素进行了详尽分析,并提出了提高测温精度的相应措施．实验结果表明,在测温范围673～1473K内,温度测量的不确定度在0．3％以内,符合设计要求。     

数理统计方法在分析测试中的应用

八十年代初,为判明误差,应用数学、试验设计、数据分析等被广泛应用在分析测试中,因Excel能运算一些的数学公式,使数理统计方法在监测中的应用更为便捷,为查明监测误差,并把所有误差减少到允许的范围内,为保证监测质量做出了贡献。     

在数控机床上零件某特征中心坐标的找定法

介绍一种在数控机床上待加工零件中心线坐标的找定法,并对此方法的原理、操作步骤、特点和操作中的注意事项作了详细说明。     

商品房面积测量误差的原因与解决办法

文章分析了商品房面积测量误差产生的原因针对由开发商擅自改变设计和施工原因、不同行业测量规范之间的不一致,以及测量部门操作中的执行口径的不统一等不同层面造成的面积测量的误差,提出了加强开发过程管理、统一行业测量口径和规范、政策修订与旧的政策的建议。     

Outline of a Theory of Strongly Semantic Information

This paper outlines a quantitative theory of strongly semantic information (TSSI) based on truth-values rather than probability distributions. The main hypothesis supported in the paper is that the classic quantitative theory of weakly semantic information (TWSI), based on probability distributions, assumes that truth-values supervene on factual semantic information, yet this principle is too weak and generates a well-known semantic paradox, whereas TSSI, according to which factual semantic information encapsulates truth, can avoid the paradox and is more in line with the standard conception of what generally counts as semantic information. After a brief introduction, section two outlines the semantic paradox implied by TWSI, analysing it in terms of an initial conflict between two requisites of a quantitative theory of semantic information. In section three, three criteria of semantic information equivalence are used to provide a taxonomy of quantitative approaches to semantic information and introduce TSSI. In section four, some further desiderata that should be fulfilled by a quantitative TSSI are explained. From section five to section seven, TSSI is developed on the basis of a calculus of truth-values and semantic discrepancy with respect to a given situation. In section eight, it is shown how TSSI succeeds in solving the paradox. Section nine summarises the main results of the paper and indicates some future developments.     

基于鲁棒Restless Bandits模型的多水下自主航行器任务分配策略

针对水下监测网络中多自主航行器（AUV）协同信息采集任务分配问题进行了研究。首先，为了同时考虑系统中目标传感器的节点状态与声学信道状态对AUV任务分配问题的影响，构建了水声监测网络系统的综合模型；其次，针对水下存在的多未知干扰因素并考虑了模型产生不精确的情况，基于强化学习理论将多AUV任务分配系统建模为鲁棒无休止赌博机问题（RBP）。最后，提出鲁棒Whittle算法求解所建立的RBP，从而求解得出多AUV的任务分配策略。仿真结果表明，在干扰环境下与未考虑干扰因素的分配策略相比，在系统分别选择1、2、3个目标时，鲁棒AUV分配策略对应的系统累计回报值参数的性能分别提升了5.5%、12.3%和9.6%，验证了所提方法的有效性。