用力学原理进行工测三维测边网平差和精度评定

随着电磁波测距仪的普及使用和测距精度的提高,三维测边网在工程测量中会逐渐地得到应用。但对这种网的平差及精度评定等问题,目前研究得还很不够。本文根据结构力学最小势能原理和虚功原理,采用另外一种简便的平差手段——力学平差法来讨论以上问题,并编制了BASIC语言程序。通过算例验证了这种平差方法的优点和有效性。     

带网络攻击识别机制的传感器网络分布式滤波算法

研究了面向网络攻击的无线传感器网络的分布式目标估计问题.由于测量范围有限,网络中只有部分传感器能测量到目标,而且节点受到随机的攻击从而使得测量值被注入虚假信息.在此背景下,本文提出了基于攻击检测识别策略的改进分布式卡尔曼滤波算法.在该算法中,节点首先基于设计给出的攻击识别阈值来判断其是否受到攻击,生成识别因子;然后以估计误差协方差的迹最小为信息融合原则来设计一致性卡尔曼滤波算法,对处于监测域内的运动目标进行分布式状态估计.同时,分析了算法的收敛性,明确给出了网络估计误差均方有界的随机攻击概率的充分条件.最后用数值仿真验证了算法的有效性和优越性.     

Local Perceptions of the Livelihood and Conservation Benefits of Small-Scale Livelihood Projects in Rural Madagascar

Small-scale livelihood projects are widely used in forest conservation and Reducing Emissions from Deforestation and Degradation (REDD)+ initiatives; however, there is limited information on how effective these projects are at delivering livelihood and conservation benefits. We explored local perceptions of the effectiveness of small-scale livelihood projects in delivering livelihood and conservation benefits in eastern Madagascar. Our results suggest that small-scale livelihood projects vary greatly in their ability to deliver livelihood benefits, and that the type of livelihood project (e.g., agriculture, beekeeping, fish farming, or livestock production) has a significant impact on which livelihood benefits are delivered. Many small-scale livelihood projects, regardless of project type, are perceived to contribute to forest conservation efforts. Our study highlights that small-scale livelihood projects have the potential to contribute to both improved livelihoods and enhanced forest conservation, but also illustrates the need for more information on the factors that lead to project success.     

数字式雹雨分测仪的研制

重点介绍了数字式雹雨分测仪的工作原理:通过过滤的方式成功将冰雹和雨滴分离,再利用阿基米德定律测算出降雹量。该仪器充分利用了雨量测量、GPRS数据传输、太阳能供电等先进技术,具有全自动、数字化特点及良好的组网能力。经实际野外试验观测表明,该仪器性能稳定,使用便捷。通过野外试验观测数据分析,数字式雹雨分测仪观测的雨量与其他仪器观测的雨量相比,误差在可接受范围内。由于该仪器能够实时观测到降雹量,为冰雹的观测研究提供了仪器支持。     

ZQZ TF型风向传感器电路剖析及维修方法

地面观测场往往处于空旷地区,风传感器又安装在观测场10 m以上空中,容易遭受雷击而损坏。若受损的风向传感器就此弃之,造成极大浪费。我们根据实物绘制了风向传感器的电路原理图,结合原理图分析了风向传感器的工作原理,并设计了格雷码检测电路。通过7个发光二极管能方便、直观的判断7位格雷码中是哪位出现问题,从而结合电路查找故障点及有关元件,提出了在没有专业工具的情况下,如何拆卸及焊接贴片芯片的简便易行的方法。通过几例检修实例,进一步说明分析故障原因及检修方法。     

输出非线性方程误差类系统递推最小二乘辨识方法

随着控制技术的发展,控制对象的规模越来越大,使得辨识算法的计算量也越来越大.对于结构复杂的非线性系统,特别是包含未知参数乘积的非线性系统,使得过参数化辨识方法的参数数目大幅度增加,辨识算法的计算量也急剧增加,因此探索计算量小的参数估计方法势在必行.针对输出非线性方程误差类系统,讨论了基于过参数化模型的递推最小二乘类辨识方法;为减小过参数化辨识算法的计算量和提高辨识精度,分别利用分解技术和数据滤波技术,研究和提出了基于模型分解的递推最小二乘辨识方法和基于数据滤波的递推最小二乘辨识方法.最后给出了几个典型辨识算法的计算量、计算步骤、流程图.     

输出误差系统的多新息辨识方法

研究了输出误差(OE)系统和输出误差自回归滑动平均(OEARMA)系统(即Box-Jenkins系统)的辅助模型随机梯度算法、辅助模型多新息随机梯度算法、辅助模型递推最小二乘算法、辅助模型多新息最小二乘算法,输出误差系统的修正辅助模型随机梯度算法、遗忘因子辅助模型随机梯度算法、变递推间隔辅助模型随机梯度算法、变递推间隔辅助模型多新息随机梯度算法、变递推间隔辅助模型递推最小二乘算法等,以及输出误差自回归(OEAR)系统的基于滤波的辅助模型多新息广义随机梯度算法和基于滤波的辅助模型多新息广义最小二乘算法.     

Solidarity in transboundary flood risk management: A view from the Dutch North Rhine–Westphalian catchment area

Climate change is putting pressure on water systems, and its effects transcend man-made boundaries, making cooperation across territorial borders essential. The governance of transboundary flood risk management calls for solidarity among riparians, as climate change will make river basins more prone to flooding. ‘Solidarity’ means that individuals act to support members of a particular community to which they belong. Recently, the solidarity principle has become institutionalized due to its formalization in the EU Floods Directive. However, it is not clear what solidarity means in the upstream–downstream practices of transboundary flood risk management. Understanding the meaning of solidarity is important for the development of cross-border climate adaptation governance. This article discusses the conceptualization of the solidarity principle and explores its meaning for international cooperation in the Dutch North Rhine–Westphalian border region. Our critical case study reveals that although all actors understand the importance of solidarity, they interpret it differently, often based on self-interest related to their position in the catchment. The formal inclusion of the solidarity principle in the Floods Directive can best be seen as a step in the continuous development of transboundary flood risk governance, as no striking changes in practice have been identified after its formalization.

Policy relevance

As climate change increasingly puts pressure on river basins and other shared resources, cross-border cooperation and solidarity are seen as increasingly important. This article discusses the meaning of solidarity in practice and reveals how this normative principle may contribute to transboundary climate adaptation governance. Understanding its meaning is important for future cross-border climate adaptation governance.     

渝利线岩溶地区选线设计浅析

本文根据渝利线4座岩溶隧道的选线实践,分析和归纳了渝利线在岩溶地区建设隧道存在的各种风险,并找出了控制风险的方法。在选线总体设计中坚持地质选线、环保选线原则,尽量规避和减小各种风险,系统性地提出了在此类地区具体、可操作的选线设计指导性原则,并成功应用此原则指导线路选线,在源头上将风险进行了有效控制,将渝利线控制性风险的等级降低至中低度。     

基于无反射棱镜全站仪的建筑物倾斜测量

针对传统的建筑物倾斜测量方法存在的一些缺点,提出一种基于无反射棱镜全站仪的建筑物倾斜测量方法。文中介绍了该方法的原理,对测量精度进行了分析,并给出不同情况下最有利的观测条件,用实例验证该方法的可靠性。