Modal and damage identification based on ambient excitation can greatly improve the efficiency of high-speed railway bridge vibration detection.This paper first describes the basic principles of stochastic subspace id...Modal and damage identification based on ambient excitation can greatly improve the efficiency of high-speed railway bridge vibration detection.This paper first describes the basic principles of stochastic subspace identification,peak-picking,and frequency domain decomposition method in modal analysis based on ambient excitation,and the effectiveness of these three methods is verified through finite element calculation and numerical simulation,Then the damage element is added to the finite element model to simulate the crack,and the curvature mode difference and the curvature mode area difference square ratio are calculated by using the stochastic subspace identification results to verify their ability of damage identification and location.Finally,the above modal and damage identification techniques are integrated to develop a bridge modal and damage identification software platform.The final results show that all three modal identification methods can accurately identify the vibration frequency and mode shape,both damage identification methods can accurately identify and locate the damage,and the developed software platform is simple and efficient.展开更多
The software industries in developing countries are facing enormous challenges in order to grow amid fierce competition of import from the software makers in developed countries. Open source software (OSS) movement, w...The software industries in developing countries are facing enormous challenges in order to grow amid fierce competition of import from the software makers in developed countries. Open source software (OSS) movement, which is a particular phenomenon in the software industries, seems to be a challenging opportunity for the developing countries that wants to move their own software industries up the value chain. This paper, using China as an example, identifies the issues that need to be addressed for the software industry, as well as the special characteristics of software products that need to be dealt with carefully. It proposes promoting OSS as a strategy the Chinese government should adopt to grow the software industry and the specific actions that should be taken.展开更多
随着社会经济的快速发展,智慧城市为人民的生活带来了更多的好处。为了解智慧城市国内外研究现状及发展趋势,应用CiteSpace软件对中国知网和Web of science两个数据库中从2013年—2023年的1000篇文献进行发文量、作者、关键词以及发展...随着社会经济的快速发展,智慧城市为人民的生活带来了更多的好处。为了解智慧城市国内外研究现状及发展趋势,应用CiteSpace软件对中国知网和Web of science两个数据库中从2013年—2023年的1000篇文献进行发文量、作者、关键词以及发展趋势的可视化分析。结果表明:1)从发文数量分析,关于“智慧城市”的发文量总体稳步上升;2)从作者分析,不同的研究人员与机构之间的合作不够紧密,在未来关于“智慧城市”文献的发展还需多加联系;3)从关键词分析,“智慧城市”相关领域研究的关键词与大数据具有关联性,在一定程度上表明了关于“智慧城市”的研究具有创新性;中国学者善于从多个角度进行研究探讨,探讨具有创新性,相反国外学者更具有现实性,从民生服务角度进行研究;4)从未来发展趋势分析,需注重数据、信息技术的发展,以及智慧城市的建设与民生的关系。本文研究成果可为该领域学者提供基础和研究思路,并为政府制定智慧城市建设相关政策提供参考。展开更多
文摘Modal and damage identification based on ambient excitation can greatly improve the efficiency of high-speed railway bridge vibration detection.This paper first describes the basic principles of stochastic subspace identification,peak-picking,and frequency domain decomposition method in modal analysis based on ambient excitation,and the effectiveness of these three methods is verified through finite element calculation and numerical simulation,Then the damage element is added to the finite element model to simulate the crack,and the curvature mode difference and the curvature mode area difference square ratio are calculated by using the stochastic subspace identification results to verify their ability of damage identification and location.Finally,the above modal and damage identification techniques are integrated to develop a bridge modal and damage identification software platform.The final results show that all three modal identification methods can accurately identify the vibration frequency and mode shape,both damage identification methods can accurately identify and locate the damage,and the developed software platform is simple and efficient.
文摘The software industries in developing countries are facing enormous challenges in order to grow amid fierce competition of import from the software makers in developed countries. Open source software (OSS) movement, which is a particular phenomenon in the software industries, seems to be a challenging opportunity for the developing countries that wants to move their own software industries up the value chain. This paper, using China as an example, identifies the issues that need to be addressed for the software industry, as well as the special characteristics of software products that need to be dealt with carefully. It proposes promoting OSS as a strategy the Chinese government should adopt to grow the software industry and the specific actions that should be taken.
文摘随着社会经济的快速发展,智慧城市为人民的生活带来了更多的好处。为了解智慧城市国内外研究现状及发展趋势,应用CiteSpace软件对中国知网和Web of science两个数据库中从2013年—2023年的1000篇文献进行发文量、作者、关键词以及发展趋势的可视化分析。结果表明:1)从发文数量分析,关于“智慧城市”的发文量总体稳步上升;2)从作者分析,不同的研究人员与机构之间的合作不够紧密,在未来关于“智慧城市”文献的发展还需多加联系;3)从关键词分析,“智慧城市”相关领域研究的关键词与大数据具有关联性,在一定程度上表明了关于“智慧城市”的研究具有创新性;中国学者善于从多个角度进行研究探讨,探讨具有创新性,相反国外学者更具有现实性,从民生服务角度进行研究;4)从未来发展趋势分析,需注重数据、信息技术的发展,以及智慧城市的建设与民生的关系。本文研究成果可为该领域学者提供基础和研究思路,并为政府制定智慧城市建设相关政策提供参考。
