CONTROL OF BUILDING VIBRATIONS WITH ACTIVE/PASSIVE DEVICES

Two linear optimal control laws and a non-linear control strategy are critically evaluated. They are implemented in a ten-story frame structure. For the linear control laws, both an active bracing system and a hybrid mass damper are considered as control devices, while the non-linear control law can be implemented with either an active or semi-active bracing system. The active and semi-active systems are compared to a passive bracing system with linear viscous dampers and to a hybrid system consisting of a passive bracing and a hybrid mass damper. Dimensionless indices based on the reduction of the maximum story drift and on the maximum control force required are introduced to compare the efficiencies of different control strategies. While the linear optimal control laws exhibit an excellent performance, the non-linear control law, in addition to its simplicity and robustness, appears to be more efficient when the allowable control force is within a certain limit. Furthermore, one attractive feature of the latter is that it can be implemented with semi-active devices to minimize the power requirement.     

武昌台JCZ-1地震计LP通道的信号分析

对武汉地震基准台JCZ-1超宽频地震计加速度信号通道的记录数据进行了分析,并对其中垂直分量记录的信息进行了潮汐计算。结果表明：JCZ-1超宽频地震计LP加速度通道记录的观测信号以固体潮汐信息为主,其中垂直分量记录的主要是重力固体潮,其观测基本达到传统固体潮仪器的精度水平。给出了经典的Venedikov调和分析结果。     

GIS组件的农产品安全管理信息系统的设计与应用

利用Visual Basic6．0(VB 6．0)和美国ESRI的组件-MapObjects 2．0(MO)集成开发了浙江省主要农产品安全管理信息系统(ZJCSMIS),通过全省1:25万空间数据库和重点县市1:5万遥感影像空间数据库,结合农产品采样点属性数据库和农产品安全标准数据库,实现对全省和重点县市不同尺度的样点分布图的分类显示、缩放、漫游、属性标识、农产品安全行业标准咨询、空间定位查询及统计分析等功能,对土壤和作物样品的属性及测试结果进行专题显示,并可实现农产品安全信息数据的更新,为浙江省主要农产品安全信息的管理提供一个合理高效的平台。     

ArcGeophysics 1.0:GIS环境下综合处理、解释地球物理与地质、地球化学、遥感等资料的组件(COM)包与应用实例

地球物理资料综合处理与解释在油气、煤田、矿物勘探\[5\]、水文分析、水文工程与环境评价中有重要应用.然而,目前的(位场)地球物理处理与解释可视化程度低,无法利用其它资料有效的约束、关联分析与综合快速解释.虽然地理信息系统(GIS)是目前综合多种资料,进行空间处理、分析,提供决策支持的强有力工具,但是,GIS是为一般地理问题分析定制的,缺少综合地球物理处理解释的工具.本文给出了解决上述问题的,用组件对象模型(COM)实现的软件包－ArcGeophysics. 在ArcGeophysics中,实现了勘探数据的有效管理,空间统计分析,地球物理（正演、反演）,地球化学与遥感处理、分析、解释与可视化,信息集成与勘探靶区预测等功能.特别需要指出的是：(1) ArcGeophysics 无缝地结合了ArcObject (ArcGIS, ESRI),也就继承了当前国际上占主导地位的GIS软件包中所有的GIS功能;(2) ArcGeophysics是建立在COM基础之上,任何支持COM的应用环境(如MS Office),编程环境(如MS Visual Studio (.Net), Borland Delphi等都可以调用这些功能(相当于通用开发工具包); (3)ArcGeophysics对地球物理资料的处理解释结合了非线性系统、多尺度分析与多维分形理论.本文不仅给出了各向异性奇异性的应用实例,而且还给出了位场在Fourier空间处理分数维导数,以及在余弦变换空间多维分形模型(C-SA).本文应用加拿大Nova Scotia省南半部的地球物理、地球化学、地质与成矿资料进行了试算,得到了理想的结果,文中图２～图５均直接出之ArcGeophysics的输出.     

Review of methods for the detection and estimation of trends with emphasis on water quality applications

Methods for the detection and estimation of trends which are suitable for the type of data sets available from water quality and atmospheric deposition monitoring programmes are considered. Parametric and non-parametric methods which are based on the assumption of monotonic trend and which account for seasonality through blocking on season are described. The topics included are heterogeneity of trend, missing data, covariates, censored data, serial dependence and multivariate extensions. The basis for the non-parametric methods being the method of choice for current large data sets of short to moderate length is reviewed. A more general definition of trend as the component of gradual change over time is consistent with another group of methods and some examples are given. Spatial temporal data sets and longer temporal records are also briefly considered. A broad overview of the topic of trend analysis is given, with technicalities left to the references cited. The necessity of defining what is meant by trend in the context of the design and objectives of the programme is emphasized, as is the need to model the variability in the data more generally.     

ESTIMATING INFILTRATION PARAMETERS FROM BASIC SOIL PROPERTIES

Infiltration data were collected on two rectangular grids with 25 sampling points each. Both experimental grids were located in tropical rain forest (Guyana), the first in an Arenosol area and the second in a Ferralsol field. Four different infiltration models were evaluated based on their performance in describing the infiltration data. The model parameters were estimated using non-linear optimization techniques. The infiltration behaviour in the Ferralsol was equally well described by the equations of Philip, Green–Ampt, Kostiakov and Horton. For the Arenosol, the equations of Philip, Green–Ampt and Horton were significantly better than the Kostiakov model. Basic soil properties such as textural composition (percentage sand, silt and clay), organic carbon content, dry bulk density, porosity, initial soil water content and root content were also determined for each sampling point of the two grids. The fitted infiltration parameters were then estimated based on other soil properties using multiple regression. Prior to the regression analysis, all predictor variables were transformed to normality. The regression analysis was performed using two information levels. The first information level contained only three texture fractions for the Ferralsol (sand, silt and clay) and four fractions for the Arenosol (coarse, medium and fine sand, and silt and clay). At the first information level the regression models explained up to 60% of the variability of some of the infiltration parameters for the Ferralsol field plot. At the second information level the complete textural analysis was used (nine fractions for the Ferralsol and six for the Arenosol). At the second information level a principal components analysis (PCA) was performed prior to the regression analysis to overcome the problem of multicollinearity among the predictor variables. Regression analysis was then carried out using the orthogonally transformed soil properties as the independent variables. Results for the Ferralsol data show that the parameters of the Green–Ampt and Kostiakov model were estimated relatively accurately (maximum R² = 0.76). For the Arenosol, use of the second information level together with PCA produced regression models with an R² value ranging from 0.38 to 0.68. For the Ferralsol, most of the variance was explained by the root content and organic matter content. In the Arenosol plot, the fractions medium and fine sand explained most of the observed variance.     

非线性成矿预测理论:多重分形奇异性-广义自相似性-分形谱系模型与方法

介绍了“奇异性-广义自相似性-分形谱系”(“3S”: Singularity-generalized self-Similarity-fractal Spectrum)为核心的多重分形现代成矿预测理论与模型(Multifractal Mineralization Prediction Theory and Models)的基本内容和前沿研究方向.讨论了作为非线性、复杂性理论的重要领域之一, 多重分形理论所提供的“奇异性-广义自相似性-分形谱系”等概念和相关的模型.这些新概念和模型不仅能够合理地描述成矿系统、成矿过程、成矿富集规律、矿产资源时空分布, 还提供了定量模拟和识别成矿异常(地质、地球物理、地球化学、遥感异常)的有效模型和实用方法.将多重分形原理与成矿过程、矿产资源分布规律、矿产资源信息获取研究相结合, 可形成具有良好应用前景的现代成矿预测理论与模型.采用该多重分形矿产资源预测理论和在此基础上所开发的专用地学非线性空间信息GeoDASGIS技术, 对国内外多个金属成矿区带进行了矿产资源勘查与评价, 均取得了较理想的预测效果, 表明对开展矿产资源勘查和评价是有效和可行的.      

基于数字地磁资料的滤波幅相法初步应用研究

根据地磁垂直分量日变化畸变异常的周期特征, 应用FHD磁力仪分钟值观测资料, 通过富氏拟合滤出1~3 h的日变化,突出垂直分量日变化中的畸变变化, 直接获取了幅相法异常。 新方法只需单台的垂直分量分钟值观测资料, 克服了原有幅相法需要参考台资料的缺陷, 方便了异常提取, 拓展了数字地磁观测资料的应用范围。     

一种优化地震前兆观测点布设的方法

使用基于主成分分析的优化地震前兆观测点方法, 用1998年数据对上海地区的9个水氡观测台站进行优化。 结果表明, 可以撤消3个信息量较小的台站观测, 剩下的6个台所含信息量占全部9个台站信息量的比例为93.0%。 表明在地震前兆观测中, 如果局部地区的地震前兆观测台站数据具有一定的相关性, 那么即使大量增加前兆观测台站的数量, 也并不意味着所获取的信息量会同步增多。 文中所用的优化方法对于指导地震前兆观测台站的优化具有一定意义。     

基于MODIS的2006-2016年西藏生态质量综合评价及其时空变化

针对缺少基于遥感数据产品的西藏地区植被生态参数筛选及综合评价的研究现状,以2006年和2016年西藏地区MODIS卫星遥感产品反演得到的植被覆盖度、叶面积指数、植被总初级生产力、区域热度与改进的湿度5项指标为基础,提出了基于主成分分析法的西藏植被生态环境质量评价方法,并探索了其时空变化规律及机理。结果表明：① 西藏地区植被生态质量整体较为脆弱,且区域差异明显,呈现东南优、西北差的分布格局。② 2006-2016年间西藏地区植被生态质量总体呈现变好的趋势。在时间序列上,2006-2016年间改善、退化的区域占比分别为31.88%和4.13%;在空间分布上,变好的区域分布在西北、中部和东部,变差的区域集中在东南部。③ 水热状况改善特别是降水量的增加和人为保护政策使得研究区西部和中部地区生态质量有所提高。社会经济活动加强是研究区东南部生态质量变差的主要原因。