共查询到20条相似文献，搜索用时 31 毫秒
1.
一种新地震定位方法研究 总被引：2，自引：0，他引：2
提高地震定位精度一直是地震学应用研究的重要课题之一,目前已经发展了多种方法用于台网定位。这些方法的共同弱点是应对复杂情况的能力差、震后处理时间过长、不能根据地震信息的增加自动修改速度模型而提高下一次地震定位的精度。开发地震台网资源,使之实现地震预警的功能,必须解决地震快速定位问题。为此,本文提出了一种基于地震台网资料的网格化地震定位方法。震前建立每个区间网格到台站的理论走时数据库,震时仅通过优化搜索,以每两个台站的到时差与理论走时差之间的方差最小的网格位置为震源,并得到发震时刻。通过在黑龙江省地震台网的实际应用说明方法可靠,精度较高。 相似文献
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The Newmark sliding block displacement function, the curve showing the relation between the sliding response and the critical acceleration ratio, is important because its applications have been widespread in seismic designs of earth structures. The aims of this article are twofold: (a) to give a new point of view on the related abscissa parameter, and (b) to provide a new methodology for better understanding the displacement functions. Regarding the new methodology, the study of the properties of the displacement functions is divided into two parts: one is the property of the amplitude at a specific abscissa, and the other is the shape property. After derivations, validations and calibrations, the authors have obtained a simple expression for the characteristic slippage. Simple expressions have also been obtained for the shapes of the displacement functions using observations and derivations. The authors compare their results for the characteristic slippage predictions and for the shapes of displacement functions with related previous studies. Finally, empirical attenuation relationships of the characteristic slippage for different ground types are developed. 相似文献
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P. S. Martyshko E. N. Akimova V. E. Misilov 《Izvestiya Physics of the Solid Earth》2016,52(5):704-708
New methods for solving the three-dimensional inverse gravity problem in the class of contact surfaces are described. Based on the approach previously suggested by the authors, new algorithms are developed. Application of these algorithms significantly reduces the number of the iterations and computing time compared to the previous ones. The algorithms have been numerically implemented on the multicore processor. The example of solving the structural inverse gravity problem for a model of four-layer medium (with the use of gravity field measurements) is constructed. 相似文献
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考虑上部结构的刚度和阻尼,使用神经网络控制算法计算基底摩擦力的大小,研究了滑移隔震结构的半主动控制。对计算实例的分析表明,通过半主动控制的滑移隔震结构不但具有较好的隔震效果,且能有效地减小基底的最大滑移量及残余位移。为对比各种控制方法的控制效果,文中还利用Bang-Bang控制和瞬时最优控制算法对滑移隔震结构进行了半主动控制。对比分析表明,基于神经网络控制算法的控制效果优于其它控制算法,具有反馈量少,稳健性强等特点。 相似文献
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非平稳空间相关多点地震动合成方法研究 总被引：1，自引：0，他引：1
根据地震波的传播特点,在现有的非平稳空间相关多点地震动合成方法的基础上进行了改进。通过修正随机相位角,使生成的多点地震动在局部场地上具有收敛性。给出了未知和已知相位差谱统计规律2种情况下非平稳多点地震动的合成方法。进一步提出了基于实际地震纪录的空间相关多点地震动合成方法。这些方法可用于大尺度结构的多点输入分析。 相似文献
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西藏中部及其与青海邻近地区强震活动特征与玛尼7.5级地震预测研究 总被引：2，自引：0，他引：2
依据西藏中部强震活动特征及１９８５年以来中国大陆强震活动新格局,于１９９６年将藏北玛尼一唐古拉山口一带列为未来几年７１／４级地震危险区。这旬刚发生的１９９７．１１．８玛尼７．５级地震有较好的对应。再次表明采用活构造与强震研究相结合、震源区个性和地震带（区）共性相结合,追踪大震发展过程及研究不同必质的强震活动图象等分析方法是有研究前景的。 相似文献
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论述了孟连７．３级地震的中、短、临三个阶段较成功预报的过程及所取得的减灾效益，同时较详细介绍了地球整体观的预报思路，提出孕震系统是一个开放的复杂巨系统，应将源、场及地球环境视为一个整体，各子系统内部和它们之间存在非线性的相互约束和反馈的观点。在预报研究进展方面阐述了建立多维预报指标、预报新方法的应用，孕震系统宏观层次上的单元体应力水平群体涨落模型等有关内容 相似文献
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《水文研究》2003,17(1):187-188
Comments by, and interviews with, authors, editors, and others responsible for carefully and dutifully shepherding intellecutal thoughts into published text will soon appear in this section. Dr. Jeff J. McDonnell, editor of HPToday, has approved the inclusion of this new feature. The rational in this decision to forgo a critical second opinion on the value of the book stems from our observation that books received by HPToday have often been reviewed by other respectable press (e.g., NY Times Book Review, Science Book Review, etc.), and a more unique angle might interest Hydrological Processes readers. The first group of authors has responded favourably to the notion of explaining their inspirations and frustrations and intentions in creating a published work. Please keep coming back to read more about the hydrological field! Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
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《水文研究》2002,16(16):3307-3308
Comments by, and interviews with, authors, editors, and others responsible for carefully and dutifully shepherding intellecutal thoughts into published text will soon appear in this section. Dr. Jeff J. McDonnell, editor of HPToday, has approved the inclusion of this new feature. The rational in this decision to forgo a critical second opinion on the value of the book stems from our observation that books received by HPToday have often been reviewed by other respectable press (e.g., NY Times Book Review, Science Book Review, etc.), and a more unique angle might interest Hydrological Processes readers. The first group of authors has responded favourably to the notion of explaining their inspirations and frustrations and intentions in creating a published work. Please keep coming back to read more about the hydrological field! Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
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《水文研究》2002,16(17):3517-3518
Comments by, and interviews with, authors, editors, and others responsible for carefully and dutifully shepherding intellecutal thoughts into published text will soon appear in this section. Dr. Jeff J. McDonnell, editor of HPToday, has approved the inclusion of this new feature. The rational in this decision to forgo a critical second opinion on the value of the book stems from our observation that books received by HPToday have often been reviewed by other respectable press (e.g., NY Times Book Review, Science Book Review, etc.), and a more unique angle might interest Hydrological Processes readers. The first group of authors has responded favourably to the notion of explaining their inspirations and frustrations and intentions in creating a published work. Please keep coming back to read more about the hydrological field! Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
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《水文研究》2003,17(4):879-880
Comments by, and interviews with, authors, editors, and others responsible for carefully and dutifully shepherding intellecutal thoughts into published text will soon appear in this section. Dr. Jeff J. McDonnell, editor of HPToday, has approved the inclusion of this new feature. The rational in this decision to forgo a critical second opinion on the value of the book stems from our observation that books received by HPToday have often been reviewed by other respectable press (e.g., NY Times Book Review, Science Book Review, etc.), and a more unique angle might interest Hydrological Processes readers. The first group of authors has responded favourably to the notion of explaining their inspirations and frustrations and intentions in creating a published work. Please keep coming back to read more about the hydrological field! Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
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《水文研究》2003,17(3):691-692
Comments by, and interviews with, authors, editors, and others responsible for carefully and dutifully shepherding intellecutal thoughts into published text will soon appear in this section. Dr. Jeff J. McDonnell, editor of HPToday, has approved the inclusion of this new feature. The rational in this decision to forgo a critical second opinion on the value of the book stems from our observation that books received by HPToday have often been reviewed by other respectable press (e.g., NY Times Book Review, Science Book Review, etc.), and a more unique angle might interest Hydrological Processes readers. The first group of authors has responded favourably to the notion of explaining their inspirations and frustrations and intentions in creating a published work. Please keep coming back to read more about the hydrological field! Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
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This contribution is aimed at a comparison of two different methods of how to deal with the solid inner core in geodynamo models. The first method, based on a direct application of the non-slip boundary conditions, was frequently used in the past. The second one, developed by the authors of the present paper, is based on an advanced analytical solution within the boundary layers and consequent formulation of new boundary conditions on the flow in the volume of the outer core. As an example we have used the results obtained by Hollerbach (1997) in the study of the influence of an imposed axial magnetic field on the fluid flow in a differentially rotating spherical shell. In the case of a weak imposed magnetic field, our solutions are very similar to those of Hollerbach. This non-trivial correspondence confirms the correctness of both methods, which are different not only in the formulation of boundary conditions, but also in the numerical methods: whereas Hollerbach used spectral methods, our computer code is based on finite differences. The influence of the conductivity of the inner core on the fluid flow was also studied. 相似文献
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三维锥束扫描CT成像图像重建新进展 总被引：1，自引：0，他引：1
介绍了作者在CT成像理论研究和工程应用实践中关于图像重建、图像处理和理解方面的成果,以及对未来的展望.主要的成果包括四个方面:一是研究三维CT重建常用算法的特点和固有误差,提出改进重建图像质量的新方法;二是从研究算法重建的优化准则出发,实现不同的重建方法;三是从应用任务出发对重建图像的性能进行理论和仿真研究;四是从应用实际问题出发,提出图像处理和理解的有效方案. 相似文献
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ABSTRACT The authors make a general survey of the methods of measuring soil permeability in the field, looking at them from the point of view of the hydrologist. In the first part they describe new equipment built by the ORSTOM Centre in Lome, Togo, to apply the Muntz method of vertical infiltration under constant head, equipment using a double cylinder and semi-automatic regulation of the discharge. In the second part, the authors make a mathematical analysis of the Porchet method of horizontal infiltration in a borehole full of water: they show that results may be interpreted even with heterogeneous (multi-layered) soils and that the calculations are simplified using a computer programme. In conclusion they deal with some results of measurements obtained by the two methods, and examine their accuracy and their correlation with the physical and hydrodynamics characteristics of the soils. 相似文献
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基于BP神经网络模型的多层砖房震害预测方法 总被引：8，自引：2，他引：8
针对传统的基于地震烈度的建筑物震害预测方法的不足,本文以地震动峰值加速度作为建筑物震害预测的地震动指标,结合几次大地震中多层砖房的震害实例,提出了一种基于BP神经网络模型的建筑物震害预测方法,模型的输入为反映结构抗震性能的各类物理参数,输出为给定地震动峰值加速度下建筑物破坏状态的概率。研究表明:基于BP网络模型的多层砖房的震害预测结果与震害实例的实际情况比较吻合,本文的思路和方法可推广于其他不同类型的建筑结构的震害预测。 相似文献
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We present MOD-AGE, a new system for chronology construction. MOD-AGE can be used for profiles that have been dated using other techniques. The system uses three basic measurements for input data: activities, the atomic ratio or age, and the depth measurement. Based on the measurement results (probability distributions), MOD-AGE estimates the confidence bands of the age-depth model and uses nonparametric methods to avoid the consequences of failure to meet assumptions. Using the normal distribution of the measured data (activities, atomic ratios, depths, etc.), we applied a Monte Carlo simulation to the model age and depth values. Several fitting models could be applied to estimate the relationships. Following multiple tests, we chose the locally weighted scatterplot smoothing (LOESS) method.The stratigraphic correction procedure applied in the MOD-AGE program uses a probability calculus, which assumes that all of the sample ages are correctly estimated. The probability age distribution from the samples was used to estimate the most probable sequence in accordance with the superposition rule.This study presents MOD-AGE as a tool for the chronology construction of speleothems that have been analyzed with the U-series method and compares MOD-AGE to the StalAge algorithm presented by Scholz and Hoffmann (2011).The MOD-AGE software was written in, made by Borland, RAD STUDIO 2007 and is available from the authors as freeware. 相似文献
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A low strain shear modulus plays a fundamental role in earthquake geotechnical engineering to estimate the ground response parameters for seismic microzonation. A large number of site response studies are being carried out using the standard penetration test (SPT) data, considering the existing correlation between SPT N values and shear modulus. The purpose of this paper is to review the available empirical correlations between shear modulus and SPT N values and to generate a new correlation by combining the new data obtained by the author and the old available data. The review shows that only few authors have used measured density and shear wave velocity to estimate shear modulus, which were related to the SPT N values. Others have assumed a constant density for all the shear wave velocities to estimate the shear modulus. Many authors used the SPT N values of less than 1 and more than 100 to generate the correlation by extrapolation or assumption, but practically these N values have limited applications, as measuring of the SPT N values of less than 1 is not possible and more than 100 is not carried out. Most of the existing correlations were developed based on the studies carried out in Japan, where N values are measured with a hammer energy of 78%, which may not be directly applicable for other regions because of the variation in SPT hammer energy. A new correlation has been generated using the measured values in Japan and in India by eliminating the assumed and extrapolated data. This correlation has higher regression coefficient and lower standard error. Finally modification factors are suggested for other regions, where the hammer energy is different from 78%. 相似文献