粒子加速器冷却储存环三维测量控制网中高程基准面的选择

介绍了冷却储存环（CSRm： Cooling Storage Main Ring）工程控制网的建立和测量概况,通过Leica高精度电子水准仪建立高程控制网,并引入到激光跟踪仪的控制网测量中,通过SA（Spa tial Ana lyzer）软件的数据处理和分析,解决了API Tracker3激光跟踪仪“精确找平”和水准测量精度低的难题。     

Application of Active Contour Model in Tracking Sequential Nearshore Waves

In the present study,a generalized active contour model of gradient vector flow is combined with the video techniques of Argus system to delineate and track sequential nearshore wave crest profdes in the shoaling process,up to their breaking on the shorehne.Previous applications of active contour models to water wave problems are limited to controllable wave tank experiments.By contrast,our application in this study is in a nearshore field environment where oblique images obtained under natural and varying condition of ambient light are employed.Existing Argus techniques produce plane image data or time series data from a selected small subset of discrete pixels.By contrast,the active contour model produces line image data along continuous visible curves such as wave crest profdes.The combination of these two existing techniques,the active contour model and Argus methodologies,facilitates the estimates of the direction wave field and phase speeds within the whole area covered by camera.These estimates are useful for the purpose of inverse calculation of the water depth.Applications of the present techniques to Hsi-tzu bay where a beach restoration program is currently undertaken are illustrated.This extension of Argus video techniques provides new application of optical remote sensing to study the hydrodynamics and morphology of a nearshore environment.     

速度传感反馈地震计的环路噪声输出传递特性分析

反馈地震计自身的噪声输出决定了它的动态范围下限.反馈地震计的噪声主要由反馈环内有源器件产生.速度传感反馈地震计的环路参数和滤波类型将会影响环内不同位置的噪声输出传递函数.本文分析了4种一阶环路滤波器和零阶环路滤波器对环内噪声传递函数的影响,开环阻尼D1较小的一阶极点高通、一阶零点高通和双一阶环路滤波在抑制前向通道噪声输出方面具有潜力;一阶极点高通在抑制反向通道低端带外噪声输出方面有较好的性能.     

RSDA-1型24位水库地震数据采集器的标定系统

RSDA-1型24位水库地震数据采集器中标定系统是测定地震计和参数的关键工具,是评判台站每天工作状态是否正常的评判手段,是标定系统特性的必须环节.根据地震计和台站不同需要,需在采集器中设计4种标定信号,即脉冲标定、正弦标定、伪随机信号和高阶脉冲信号.本文主要介绍标定系统及4种标定信号在24位地震数据采集器中的设计和实现.     

Application of clan member signal method in structural damage detection

It is well known that in most cases, a reference is necessary for structural health diagnosis, and it is very difficult to obtain such a reference for a given structure. In this paper, a clan member signal method (CMSM) is proposed for use in structures consisting of groups (or clans) that have the same geometry, i.e., the same cross section and length, and identical boundary conditions. It is expected that signals measured on any undamaged member in a clan after an event could be used as a reference for any other members in the clan. To verify the applicability of the proposed method, a steel truss model is tested and the results show that the CMSM is very effective in detecting local damage in structures composed of identical slender members.     

Characteristics of response spectra for long-periods of main-shock recordings of the Chi-Chi earthquake

Current practice uses predictive models to extrapolate long-period response spectra based on far-field recordings in moderate and weak earthquakes. However, the spectra are not long enough and the data are often not reliable, which means that the seismic design code cannot accurately define seismic design requirements for long-period structures. The near-field recordings in the main-shock of the Chi-Chi earthquake have a large signal-to-noise ratio (SNR), which makes them suitable for studying the long-period acceleration response spectrum up to 20 sec. The acceleration response spectra from 246 stations within 120 km of the causative fault are statistically analyzed in this paper. The influence of distance and site conditions on long-period response spectrum is discussed, and the shapes of the amplification spectra are compared with the standard spectra specified in the seismic design code of China. Finally, suggestions for future revisions to the code are proposed.     

基于Choi-Williams时频分布的阵列声波测井信号时频分析

对多极子阵列声波测井信号,提出了一种基于信号时、频局域相关能量的新的时-频信号分析方法,Choi-Williams能量分布,它有着较明确的物理意义.该分析方法对于不同岩性的构造的响应具有很好的区分和识别能力,其声波全波列的Choi-Williams能量分布对由不同岩性组成的构造破碎带具有明显不同的表现特征.利用相应的模式识别方法,可以对这些岩性构造进行有效的区分和识别.     

从CSAMT信号中提取IP信息探讨

CSAMT信号数据进行反演时,认为电阻率是一个与频率无关的实数,而实际上因为激电效应,地下可极化体的电阻率是一个与频率有关的复数.从CSAMT信号中提取激电信息可以加大激电法的使用范围,并可以提高CSAMT法勘探的精度.本文总结了国内外在这方面研究现状,介绍了从CSAMT法信号中提取激电信息的基本原理,并提出了未来值得深入研究的几个方面.     

优化栅格细化算法的线状地物提取

栅格细化算法是处理栅格矢量数据相互转换的常用算法。本文对该算法进行了优化处理,实现了栅格矢量化半自动跟踪和面状地物中心线提取。两种功能的实现都采用人机交互的策略,可以实时、有选择性地提取结果。在栅格转矢量过程中对栅格底图的颜色和质量要求不高,转换速度快、精度高、实用性强,不受内存等硬件限制,可用于GIS数据处理软件,便于推广。     

基于方向信息约束的遥感平台强跟踪定位算法

为了提高机载遥感平台在应对气流抖动和外界强干扰时的定位性能,在加速度自适应截断正态分布的基础上,通过Lagrange乘子法将速度方向信息约束到强跟踪滤波中,得到了基于方向信息约束的强跟踪定位算法。仿真表明:该算法通过在线控制使输出残差强制近似正交,充分利用了方向约束信息。与一般的强跟踪算法相比较,在提高定位精度的同时可及时响应空中机动,较好地解决了机载遥感平台在强机动干扰条件下的跟踪定位问题。