控制性深孔地震输入界面位置的确定方法和影响研究     

洪海春  许汉刚  陶小三  邵斌  薛莹莹 《震灾防御技术》2013,8(1):52-61

探讨了在工程场地地震安全性评价的地震反应分析模型中,江苏省盐城地区部分工程场地内深度超过100m时剪切波速仍小于500m/s的控制性深孔,采用近似估算方法弥补所缺波速值和确定地震输入界面后,进行波速值和地震输入界面位置的不确定性对工程场地地震反应的影响研究,包括地表地震动峰值加速度和反应谱特征周期等,为其他地区控制性深孔的地震输入界面位置的确定方法和影响研究提供参考。  相似文献   

基于边缘指导的双通道卷积神经网络单图像超分辨率算法     

李春平  周登文  贾慧秒 《南京气象学院学报》2017,9(6):669-674

当前基于卷积神经网络（CNN）的超分辨率（SR）重建算法,虽然取得了很大的成功,但是重建图像高频纹理的效果仍然不能令人满意,其高分辨率（HR）图像局部边缘存在明显的震荡.本文提出一种结合形态学成分分析（MCA）分解的边缘指导双通道CNNSR算法：待处理的低分辨率（LR）图像通过MCA分解为纹理部分和平滑结构部分;纹理部分和原LR图像共同组成双通道,输入到改进的网络结构中重建HR纹理部分;结合HR纹理输出与LR平滑结构部分重建HR图像.训练过程采用最小化纹理损失与原图像损失之和最优化网络模型参数.后处理包括：执行网络输出与LR输入图像的直方图匹配使色调保持一致,提升感官效果;应用迭代的反向映射使HR重建与LR输入保持退化算子一致性提高PSNR值.实验结果显示：该方法能够很好地恢复HR图像的纹理细节,对纹理细节丰富的图像恢复效果更好.  相似文献   

辅助模型辨识方法(5):最小二乘辨识     

丁锋 《南京气象学院学报》2016,8(5):385-403

借助于辅助模型辨识思想,针对白噪声干扰的输入非线性有限脉冲响应系统,研究了辅助模型最小二乘辨识方法、辅助模型多新息最小二乘辨识方法、变递推间隔辅助模型最小二乘辨识方法、变递推间隔辅助模型多新息最小二乘辨识方法、等递推间隔辅助模型多新息最小二乘辨识方法,以及有限数据窗最小二乘辨识方法,包括引入加权因子（加权矩阵）、遗忘因子得到的一些相应辨识方法.  相似文献   

Origin of crude oils from oilfields in the Zagros Fold Belt,southern Iraq: Relation to organic matter input and paleoenvironmental conditions     

《Marine and Petroleum Geology》2016

Crude oil samples from Cretaceous and Tertiary reservoir sections in the Zagros Fold Belt oil fields, southern Iraq were investigated using non-biomarker and biomarker parameters. The results of this study have been used to assess source of organic matter, and the genetic link between oils and their potential source rocks in the basin. The oils are characterized by high sulphur and trace metal (Ni, V) contents and relatively low API gravity values (17.4–22.7° API). This indicates that these oils are heavy and generated from a marine source rock containing Type II-S kerogen. This is supported by their biomarker distributions of normal alkanes, regular isoprenoids, terpanes and steranes and the bulk carbon isotope compositions of their saturated and aromatic hydrocarbons. The oils are characterized by low Pr/Ph ratios (<1), high values of the C₃₅ homohopane index and C₃₁-22R/C₃₀ hopane ratios, relatively high C₂₇ sterane concentrations, and the predominance of C₂₉-norhopane. These biomarkers suggest that the oils were generated predominantly from a marine carbonate source rock, deposited under reducing conditions and containing plankton/algal and microorganisms source input. The presence of gammacerane also suggests water column stratification during source rock deposition.The biomarker characteristics of the oils are consistent with those of the Middle Jurassic Sargelu carbonate as the effective source rock in the basin. Biomarker maturity data indicate that the oils were generated from early maturity source rocks.  相似文献   

The effect of industrialization and globalization on domestic land-use: A global resource footprint perspective     

《Global Environmental Change》2021

Land-use activities are increasingly globalized and industrialized. While this contributes to a reduction of pressure on domestic ecosystems in some regions, spillover effects from these processes represent potential obstacles for global sustainable land-use. This contribution scrutinizes the complex global resource nexus of national land-use intensity, international trade of biomass goods, and resource footprints in land-use systems. Via a systematic account of the global human appropriation of net primary production (HANPP) and input–output modelling, we demonstrate that with growing income countries reduce their reliance on local renewable resources, while simultaneously consuming more biomass goods produced in other countries requiring higher energy and material inputs. The characteristic 'outsourcing' country appropriates 43% of its domestic net primary production, but net-imports a similar amount (64 gigajoules per capita and year) from other countries and requires energy (11 GJ/cap/yr) and material (~400 kg/cap/yr) inputs four to five times higher as the majority of the global population to sustain domestic land-use intensification. This growing societal disconnect from domestic ecological productivity enables a domestic conservation of ecosystems while satisfying growing demand. However, it does not imply a global decoupling of biomass consumption from resource and land requirements.  相似文献   

智能船舶自动舵系统自适应模糊输出反馈控制     

朱丽燕  李铁山 《南京气象学院学报》2021,13(1):22-28

针对智能船舶自动舵系统,考虑输入饱和、回转角速度未知和指定性能,提出一种自适应模糊控制算法.本文自适应模糊输出反馈算法采用状态观测器、辅助系统和误差转换系统,模糊逻辑系统用于估计未知非线性函数,状态观测器用于估计未知回转角速度状态,辅助系统和误差转换系统分别用于补偿不匹配控制信号和变换航向角追踪误差.基于Lyapunov方法证明了闭环系统内所有信号是有界的,仿真结果进一步验证了本文算法的有效性.  相似文献   

Development of a support‐vector‐machine‐based model for daily pan evaporation estimation     

Gwo‐Fong Lin  Hsuan‐Yu Lin  Ming‐Chang Wu 《水文研究》2013,27(22):3115-3127

Evaporation estimation is an important issue in water resources management. In this article, a four‐season model with optimal input combination is proposed to estimate the daily evaporation. First, the model based on support vector machine (SVM) coupled with an input determination process is used to determine the optimal combination of input variables. Second, a comparison of the SVM‐based model with the model based on back‐propagation network (BPN) is made to demonstrate the superiority of the SVM‐based model. In addition, season data are used to construct the SVM‐based four‐season model to further improve the daily evaporation estimation. An application is conducted to demonstrate the performance of the proposed model. Results show that the SVM‐based model can select the optimal input combination with physical mechanism. The SVM‐based model is more appropriate than the BPN‐based model because of its higher accuracy, robustness and efficiency. Moreover, the improvement due to the use of the four‐season model increases from 3.22% to 15.30% for RMSE and from 4.84% to 91.16% for CE, respectively. In conclusion, the SVM‐based model coupled with the proposed input determination process should be used to select input variables. The proposed four‐season SVM‐based model with optimal input combination is recommended as an alternative to the existing models. The proposed modelling technique is expected to be useful to improve the daily evaporation estimation. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

中国城镇建设用地投入的非协调性研究     

孙平军  丁四保  王颖 《世界地理研究》2012,(1):49-57

我国是一个人多地少、土地资源极度稀缺紧张、且正处在加速城市化发展阶段的发展中国家,如何落实城镇建设用地投入与地区社会经济、居民生活以及资金短缺之间的协调发展是当前城镇化发展过程中一个亟需解决的问题。城镇建设用地不仅是城镇人口城镇化、产业就业城镇化(经济城镇化)、社会城镇化(基础服务设施城镇化)的外在表征,更是一个国家(地区)资源使用效率、经济发展模式(集约抑或粗放)、社会公平公正(城镇基本服务设施的均等化)主要参考指标。故此,为了考查我国城镇建设用地投入的协调性,该文借用非协调性指数模型、分别评价城镇建设用地投入与城镇人口、GDP、地方财政税收、产业就业非农化以及社会非农化之间的非协调程度,并对其产生的原因进行了剖析。结果表明:我国城镇建设用地投入总体而言是比较协调的,从各单个省份(自治区、直辖市)来看,城镇建设用地投入至于各变量指标而言大体可以分为超前、滞后和相对协调三种类型,其中上海由于行政区划的调整以及当前户籍管理体制的作用而表现出相当程度的超前发展(粗放式发展)。最后就如何推进我国城镇建设用地投入的协调发展提供建议。  相似文献   

建立城镇地籍信息系统的关键技术研究     

谭红霞  李少华  王德峰  马培果  孙金龙 《测绘与空间地理信息》2012,35(9):136-139,144

介绍了对在城镇地籍信息管理技术中遇到的重点难点问题进行的研究和解决,主要讲述了针对空间数据的组织与优化配置管理,ArcGIS版本原理以及相关的工作流程,对历史库的设计实现历史回溯等关键技术。  相似文献   

多点输入条件下的土质边坡地震反应     

景鹏旭  杨清逸 《华北地震科学》2021,39(1):17-22

以二维土质边坡模型为例,地震输入方式分别采取单点输入和多点输入,考虑其土层地震反应、主应力极值等特征,分析单点、多点输入的差异;在此基础之上,探讨单点输入与多点输入下坡高、坡角的变化对土质边坡模型安全系数的影响。结果显示,在地震工程抗震设计时采用多点输入比单点输入更加安全、更符合实际情况。  相似文献