Nonsymmetrical loading protocols for shear links in eccentrically braced frames     

Musab Aied Qissab Al-Janabi  Cem Topkaya 《地震工程与结构动力学》2020,49(1):74-94

The AISC Seismic Provisions for Structural Steel Buildings (AISC 341-16) provide a testing protocol for qualification of link-to-column connections in eccentrically braced frames (EBFs). This symmetrical testing protocol was developed by conducting nonlinear time history analysis on representative EBFs designed according to the International Building Code. Although the testing protocol is intended for qualification of link-to-column connections, many research programs have employed this recommended protocol for testing of shear links. Recent numerical investigations on constructed EBFs and archetype models showed that links can be subjected to one-sided loadings with significantly higher link rotation angles than the codified limits. A numerical study has been undertaken to develop nonsymmetrical loading protocols for shear links in EBFs. Pursuant to this goal, 20 EBF archetypes were designed according to the ASCE7-16 standard. The main parameters investigated were the link length to bay width ratio (e/L), number of stories, type of EBF, and the ground motion level. The archetypes were subjected to maximum considered earthquake and collapse level earthquake as recommended by FEMA P695. The results showed that the history of link rotation is single sided and depends strongly on e/L and the level of ground motion. Nonsymmetrical loading protocols that depend on the aforementioned variables were developed and are presented herein.  相似文献   

基于互联网的震后虚假信息入侵实时检测系统设计          下载免费PDF全文

彭懋磊  刘可  李垠  吕筱 《地震工程学报》2020,42(1):270-275

虚假震后信息入侵严重干扰抗震救灾与灾后重建进程,为防止虚假震后信息在互联网中大肆传播,需对震后虚假信息进行精准识别,设计基于互联网的震后虚假信息入侵实时检测系统。互联网以Web服务器为载体传播信息,数据包捕获模块采用WinPcap技术,并从中获取有效数据包,在协议解析模块中完成数据包TCP/IP协议、CMP协议、UDP协议解码工作,解码后的数据输入到基于SVM的震后虚假信息检测模型中。SVM模型寻求最优超平面将震后信息分为虚假与真实两个类别,根据该结果完成震后虚假信息入侵实时检测。由实验结果可知该系统检测震后虚假信息入侵误报率低于3%,相比同类型系统具有接收数据能力强、效率高的优势,对精准检测震后虚假信息具有重要意义。  相似文献   

Use of genetic algorithm in new approach to modeling of flood routing     

EL ALAOUI EL FELS Abdelhafid  ALAA Noureddine  BACHNOU Ali 《海洋湖沼学报（英文）》2019,(1):72-78

The hydrological models and simpli?ed methods of Saint-venant equations are used extensively in hydrological modeling, in particular for the simulation of the ?ood routing. These models require speci?c and extensive data that usually makes the study of ?ood propagation an arduous practice. We present in this work a new model, based on a transfer function, this function is a function of parametric probability density, having a physical meaning with respect to the propagation of a hydrological signal. The inversion of the model is carried out by an optimization technique called Genetic Algorithm. It consists of evolving a population of parameters based primarily on genetic recombination operators and natural selection to?nd the minimum of an objective function that measures the distance between observed and simulated data. The precision of the simulations of the proposed model is compared with the response of the Hayami model and the applicability of the model is tested on a real case, the N'Fis basin river, located in the High Atlas Occidental, which presents elements that appear favorable to the study of the propagation. The results obtained are very satisfactory and the simulation of the proposed model is very close to the response of the Hayami model.  相似文献   

Changing of the guards: Detrital zircon provenance tracking sedimentological reorganization of a post-Gondwanan rift margin     

Milo Barham  Christopher L. Kirkland 《Basin Research》2020,32(5):854-874

Understanding the development of sedimentary systems during continental rifting is important for tracking environmental change and lithospheric processes. Conceptual models have been developed for the sourcing, routing and facies architecture of sediments in rift-settings, driven in part by quantitative sediment tracking. Here, we present laser ablation split-stream detrital zircon U/Pb geochronology and Hf-isotopes for post-rift (Cretaceous-Paleogene) clastic sediments from Ocean Drilling Program (ODP) wells and Plio-Pleistocene palaeoshoreline material, from the southern margin of Australia. Provenance results are contextualized through comparison with well-characterized source regions and regional pre- and syn-rift sediment reservoirs to track changes associated with Australia-Antarctica separation during East Gondwana break-up. The provenance character of the post-rift sediments studied are distinct from pre-existing sediment reservoirs and demonstrate termination of previously stable sediment routing systems and a dominance of local basement of the Proterozoic Madura and Coompana provinces (~1.2 Ga and CHUR-like Hf-signatures; Moodini Supersuite) in offshore ODP wells. A composite post-rift Cretaceous?-Eocene sample in the easternmost well expresses characteristic Phanerozoic zircon age signatures associated with source regions in eastern Australia that are interpreted to reflect inversion in the Ceduna Sub-basin to the east. Detrital zircon signatures in Plio-Pleistocene palaeoshoreline sediment are also relatively distinct, indicating derivation from coastal erosion in the Leeuwin Complex (~0.5 and 0.7 Ga subchondritic grains) and Albany–Fraser Orogen (~1.2 Ga subchondritic grains) several hundred, to over a thousand kilometers to the west. Collectively, results highlight the fundamental geological processes associated with rifting that dramatically change the character of sediment provenance via (a) isolation of pre-existing primary and secondary sources of detritus, (b) development of new source regions in basin compartmentalized highs and localized fault scarps, and (c) establishment of marine and coastal currents that redefine clastic sediment transport.  相似文献   

基于SOAP的分布式通信策略研究与实现     

安俊秀 《成都信息工程学院学报》2009,24(3)

在研究SOAP通讯原理的基础上,分析了SOAP完成通信功能所需要的主要功能模块,研究了SOAP通信功能的执行效率,由此设计出相应模块以实现分布式通信策略,提高了软件的可复用性和可移植性.实现了异构网络环境下异构平台间的互操作,使分布式资源得到更广泛的利用.  相似文献   

城市暴雨积水模拟方法分析及研究   总被引：4，自引：0，他引：4  

杨弋  吴升 《测绘信息与工程》2009,34(1):35-37

在总结目前常用城市暴雨积水模拟方法的基础上,从水体由高到低的运动机理着手,将基于数字地形分析技术的路径算法引入城市暴雨积水模拟,并考虑到管网汇流及城市地形因素,给出数据修正与算法改进的具体方法。  相似文献   

Secure Socket Layer协议在电子政务系统安全建设中的应用     

孟昊晨 《国土资源信息化》2009,(5):13-18,28

针对目前日益突出的电子政务安全问题,在Secure Socket Layer协议的基础上,对我国电子政务的安全问题进行探讨,并针对目前政府机构信息化建设中的数据安全传输问题提出几点改进工作方案。  相似文献   

BGP协议在CERNET用户接入中的应用     

李鹏飞  郝辉 《中国海洋大学学报(自然科学版)》2008,(Z1)

通过对静态路由和动态路由的考察分析,并结合CERNET用户接入现状,提出将BGP协议应用到CERNET用户接入中,采用BGP协议和静态路由相结合的混合路由方式,是1种全新的CERNET用户接入路由模式。  相似文献   

IPv6协议分析系统的设计与实现     

陈俊  傅光轩 《中国海洋大学学报(自然科学版)》2008,(Z1)

对开发基于Libpcap、Libnet的IPv6协议分析系统进行深入分析设计,并阐述具体的实现方法,详细分析各函数模块的实现。针对IPv4协议分析作了对比研究。实验结果表明:该系统能很好的实现IPv6下的协议分析。  相似文献   

一种具有多维收敛能力的内容寻址网络     

彭宗锦  楚丁 《成都信息工程学院学报》2008,23(1):16-20

CAN（Content-Addressable Network）在d维的虚拟空间中利用分布式哈希表（Distributed Hash Table,DHT）来定位资源。CAN提供了一套比较有效的路由算法,但是节点能力的异构性并没有被考虑到算法中。这里提出了一种CAN路由的改进算法,通过扩展CAN邻居的定义和重构路由表等方式,使节点的异构性被考虑在路由算法中。同时该算法使得定位消息能从多维方向向着目标区域收敛,有效地提高了CAN路由消息的效率。  相似文献