浅议如何提高天津台网地震速报的质量

为达到地震台网地震速报的相关要求,实现在最短时间内测定地震“三要素”和发送信息,文章结合天津地震台网所用MSDP软件的特点和首都圈地区的区域特征,就如何提高台网的地震速报质量,从提高地震速报的速度、准确度及专业人员的素质等方面提出改进的方法。     

基于自适应模糊神经网络预测金属——EDTA配合物稳定常数

采用自适应模糊神经网络的方法,以金属离子外层主量子数(n)、电荷(Z)、半径(r)、适配价轨道数因子(w)及价电子结构因子(S)等为参数,关联金属—EDTA配合物稳定常数。利用减法聚类算法确定模糊神经网络的结构,并结合模糊推理系统进行该网络参数的调整,网络仿真的结果是满意的。在此基础上,预测了13种金属—EDTA配合物稳定常数。     

ENVI遥感图像监督分类方法比较

鉴于遥感监督分类方法的普遍应用,本文介绍了五种常用的监督分类方法:平行六面体法、最小距离法、马氏距离法、最大似然法和人工神经网络分类法。就同一地区TM影像应用这五种方法进行了土地利用分类,对比分析了这五种方法的分类精度,发现人工神经网络对土地覆盖与利用的分类精度高于最大似然法,最大似然法分类精度优于平行六面体法、最小距离法和马氏距离法。所得结论对有关遥感图像分类工作具有指导和借鉴意义。     

《山东国土资源》网络采编系统应用分析

《山东国土资源》网络采编系统,实行在线投稿、审稿、稿件修改、进度查询等工作流程。实现了从收稿、审稿、编辑加工的计算机网络化管理和流程控制,完成了作者、审稿专家、编辑及读者之间的实时信息传递,缩短了工作环节的处理时间。分析了网络采编系统使用过程中的问题,提出合理化建议,规范了工作程序,提高了工作效率。     

The new accelerograph network for Santa Fe De Bogota, Colombia and implications for microzonation

The new accelerographic network of Santa Fe de Bogotá is composed of 29 three-component stations with sensors at the surface and three additional six-component borehole stations with three sensors at the surface and three at depth (115, 126 and 184 m). In total, 32 stations have been operative in the metropolitan area of Bogotá since 1999. During this period of time, a significant number of weak motion are recorded and used for a preliminary analysis of local site effects. Using the SH-wave response spectra we verify the behavior of the different seismic zones proposed by the previous microzonation study of the city. A comparison between normalized SH-wave response spectra and the normalized design spectra for each zone clearly depicts that parts of the design spectra should be revised, as well as the boundaries between different zones may require some changes. The spectral amplification levels reach up to a factor of 5. The predominant periods obtained by the amplification spectra in different stations in the city, show variability from 0.3 to 3.0 s. A comparison is also made between the predominant periods obtained using H/V spectral ratios of microtremors and those using weak motion. In general, microtremors tend to predict slightly lower values of dominant periods than those calculated by the weak motion spectra. However, there is a general correlation between the two data sets. Using the data recorded by one of the borehole station, an equivalent linear seismic response analysis was conducted. The modeled and recorded response spectra show similarities in period peaks, however, the modeled soil amplification is underestimated for periods less than 0.8 s. Since the available record is weak motion which represents mostly the linear response of the soils, further analysis is required.     

辽宁数字地震台网地震参数自动处理系统的研制

通过对数字地震观测台网记录的地震．P波和S波震相的振幅、周期、偏振等多种特征进行分析，利用这些特征进行地震震相自动识别，在此基础上进行自动定位。本文主要介绍了地震事件的自动判别、地震震相自动识别、地震的自动定位三个方面的内容。     

江苏省数字地震前兆观测资料的初步分析

在对江苏数字前兆观测资料分类的基础上,对其中的干扰及其特征和机理进行了初步描述,发现地电阻率观测值在远大震前的前驱波变化、自流热水井水位与地热同震效应的同步变化值得今后进一步深入研究;FHD磁力仪分量观测转向差的长期漂移,可避免今后应用该仪器观测资料时出现缪误。另外,苏16井井口脱气装置的改造对今后数字水化学观测改造有一定的借鉴作用。     

DSN Deep-Space Array-Based Network Beamformer

NASA is proposing a new receiving facility that needs to beamform broadband signals from hundreds of antennas. This is a similar problem to SKA beamforming with the added requirement that the processing should not add significant noise or distortion that would interfere with processing spacecraft telemetry data. The proposed solution is based on an FX correlator architecture and uses oversampling polyphase filterbanks to avoid aliasing. Each beamformer/correlator module processes a small part of the total bandwidth for all antennas, eliminating interconnection problems. Processing the summed frequency data with a synthesis polyphase filterbank reconstructs the time series. Choice of suitable oversampling ratio, and analysis and synthesis filters can keep aliasing below −39 dB while keeping the passband ripple low. This approach is readily integrated into the currently proposed SKA correlator architecture.