This research aimed to overcome challenges such as high costs,lengthy optimization time,and low efficiency in resolving issues related to wheel-rail contact,rail wear,and vehicle dynamics.Based on the wheel-rail conta...This research aimed to overcome challenges such as high costs,lengthy optimization time,and low efficiency in resolving issues related to wheel-rail contact,rail wear,and vehicle dynamics.Based on the wheel-rail contact parameters,an optimal design method for rail grinding target profile is proposed from wear profile measurement to grinding profile design according to the actual railway track and vehicle operating conditions.We utilized Isight to create a simulation test and developed an RBF proxy model that incorporated both mechanical and geometric aspects of wheel-rail contact.By integrating rail modeling,wheel-rail contact analysis,and multi-objective optimization,we established a rail grinding optimization model that was solved using the NSGA-II algorithm.After optimization,the study achieved a 31.863%reduction in average contact stress,a 70.5%reduction in matching wear work,and a 100.391%increase in the difference in rolling radius between the wheel and rail.展开更多
Ruby on Rails(简称ROR)是一个Web应用程序框架,以其能快速开发而备受敏捷开发实践者的推崇,它包含的重要概念有MVC模式、DSL、习惯约定优于配置、生成器、低重复等.以一个实际课题"中医药数据库共享平台"为例,研究如何应用RO...Ruby on Rails(简称ROR)是一个Web应用程序框架,以其能快速开发而备受敏捷开发实践者的推崇,它包含的重要概念有MVC模式、DSL、习惯约定优于配置、生成器、低重复等.以一个实际课题"中医药数据库共享平台"为例,研究如何应用ROR技术来满足一个实际需求的项目,涉及的技术有MVC模式、RESTful SOA、AJAX、Lighttpd&FCGI等.展开更多
This study explores the feasibility of electromagnetic acoustic transducers(EMATs)for ultrasonic rail inspection,focusing on bulk wave generation from the rail head and on defect detection at the central part of the r...This study explores the feasibility of electromagnetic acoustic transducers(EMATs)for ultrasonic rail inspection,focusing on bulk wave generation from the rail head and on defect detection at the central part of the rail foot.As a contactless method,EMATs could overcome some known limitations of conventional ultrasonic techniques,but require further validation.Differ-ent campaigns of experimental tests were performed,evaluating,by means of a probability of detection approach,the response of the technique to several artificial semi-elliptical flaws of increasing size and by considering two sensors characterized by different working frequencies.In contact,static tests allowed to assess the basic feasibility of the inspection technique and showed a linear response to defect size,saturating when defect width exceeded the rail web thickness.Dynamic tests allowed to introduce the effects of lift-off on signal responses.During all tests,the higher-frequency sensor outperformed the lower-frequency one.Finally,full-scale bogie tests on an indoor permanent track installation,comprehensive of defec-tive rails,confirmed the higher flaw detection rates of the higher-frequency sensor,with minimal detection failures despite occasional false alarms.EMATs showed encouraging results for in-motion rail inspection:with further technical development and optimization,this technique could enhance ultrasonic rail inspection by diagnostic trains.展开更多
随着Web服务的快速发展,基于REST(Representational State Transfer)风格的Web Service越来越受到业界的关注。在实现RESTful Web Service的众多框架中,Rails完整实现了MVC并对RESTful Web Service的开发作了极大的封装和简化,使得开发...随着Web服务的快速发展,基于REST(Representational State Transfer)风格的Web Service越来越受到业界的关注。在实现RESTful Web Service的众多框架中,Rails完整实现了MVC并对RESTful Web Service的开发作了极大的封装和简化,使得开发人员用Rails实现RESTful Web Service变得容易。对RESTful Web Service特征和Rails框架结构进行了概述,分析了Rails实现RESTfulWeb Service的原理,在此基础上结合实例给出了基于Rails的RESTful Web Service以及RESTful Web Service客户端的开发步骤和方法,并且利用Ruby进行了实现。展开更多
运用目前两种炙手可热的Web开发技术:AJAX和Ruby on Rails为WebGIS提供一个新的解决方案,AJAX技术作为一种新兴的网络技术比传统页面刷新模式具有更好的性能和友好的用户体验,不过在建立大量的Javascript的代码基础上的,本文通过对AJAX ...运用目前两种炙手可热的Web开发技术:AJAX和Ruby on Rails为WebGIS提供一个新的解决方案,AJAX技术作为一种新兴的网络技术比传统页面刷新模式具有更好的性能和友好的用户体验,不过在建立大量的Javascript的代码基础上的,本文通过对AJAX on Rails原理进行分析,运用Ruby on Rails的动态性和敏捷性使AJAX模式带来的程序量大、首页加载时间长的缺陷得到改善,进一步提高程序性能。在实现环节上,在该平台上结合使用Google Maps API,以GXmlHttp在Rails上实现了AJAX的WebGIS关键应用。展开更多
Ruby on Rails是一个基于Ruby语言构建的全新Web应用程序架构,为Web应用程序开发提供了一种极其快捷的途径,正在和已经引起业界相当的兴趣.在给出了Ruby on Rails与轻量级J2EE架构Struts+Hibernate关键特性的基础上,从前端控制器、动作...Ruby on Rails是一个基于Ruby语言构建的全新Web应用程序架构,为Web应用程序开发提供了一种极其快捷的途径,正在和已经引起业界相当的兴趣.在给出了Ruby on Rails与轻量级J2EE架构Struts+Hibernate关键特性的基础上,从前端控制器、动作和模型,持久性框架三个方面对两种架构进行了比较.展开更多
以SNS、BLOG等为代表的web2.0应用中,经常需要上传图片,而且要对图片进行缩放处理,得到缩略图。使用ruby on rails开发框架,通过attachment_Fu插件可以方便地实现所有这些功能。这大大提高了web应用的开发效率,符合用户对web2.0应用持...以SNS、BLOG等为代表的web2.0应用中,经常需要上传图片,而且要对图片进行缩放处理,得到缩略图。使用ruby on rails开发框架,通过attachment_Fu插件可以方便地实现所有这些功能。这大大提高了web应用的开发效率,符合用户对web2.0应用持续开发、持续改进、持续创新的要求。展开更多
新Web开发框架Ruby on Rails的迅速兴起引起了开发社区的关注,它大大提高了开发者开发可信赖的干净的应用程序的效率。本文分析了Web应用与开发领域的发展状况,将Rails的核心观念与传统框架进行对比,探讨其迅速流行与成功的原因及未来...新Web开发框架Ruby on Rails的迅速兴起引起了开发社区的关注,它大大提高了开发者开发可信赖的干净的应用程序的效率。本文分析了Web应用与开发领域的发展状况,将Rails的核心观念与传统框架进行对比,探讨其迅速流行与成功的原因及未来的前景。展开更多
为大幅度缩短针对新的教学需求的计算机辅助教学系统的开发周期,同时高效的维护系统,研究了当前流行的Ruby On Rails框架技术。基于模型-视图-控制器（model-view-controller,MVC）设计模式进行系统开发,该系统可实现注册登录、作业提...为大幅度缩短针对新的教学需求的计算机辅助教学系统的开发周期,同时高效的维护系统,研究了当前流行的Ruby On Rails框架技术。基于模型-视图-控制器（model-view-controller,MVC）设计模式进行系统开发,该系统可实现注册登录、作业提交、上机管理、上机测验、发送邮件、信息查询、作业检查、密码提醒等功能。测试结果表明了该软件的实用性。展开更多
基金Supported by Fundamental Research Funds for the Central Universities(Grant No.2019JBM050).
文摘This research aimed to overcome challenges such as high costs,lengthy optimization time,and low efficiency in resolving issues related to wheel-rail contact,rail wear,and vehicle dynamics.Based on the wheel-rail contact parameters,an optimal design method for rail grinding target profile is proposed from wear profile measurement to grinding profile design according to the actual railway track and vehicle operating conditions.We utilized Isight to create a simulation test and developed an RBF proxy model that incorporated both mechanical and geometric aspects of wheel-rail contact.By integrating rail modeling,wheel-rail contact analysis,and multi-objective optimization,we established a rail grinding optimization model that was solved using the NSGA-II algorithm.After optimization,the study achieved a 31.863%reduction in average contact stress,a 70.5%reduction in matching wear work,and a 100.391%increase in the difference in rolling radius between the wheel and rail.
文摘Ruby on Rails(简称ROR)是一个Web应用程序框架,以其能快速开发而备受敏捷开发实践者的推崇,它包含的重要概念有MVC模式、DSL、习惯约定优于配置、生成器、低重复等.以一个实际课题"中医药数据库共享平台"为例,研究如何应用ROR技术来满足一个实际需求的项目,涉及的技术有MVC模式、RESTful SOA、AJAX、Lighttpd&FCGI等.
基金funded in the frame of the Joint Research Centre (JRC) Trasporti, established at Fondazione Politecnico di Milano, through contract C40/2019 “JRC Trasporti-Metodologie per l’ispezione delle rotaie nei riguardi della formazione di cricche”
文摘This study explores the feasibility of electromagnetic acoustic transducers(EMATs)for ultrasonic rail inspection,focusing on bulk wave generation from the rail head and on defect detection at the central part of the rail foot.As a contactless method,EMATs could overcome some known limitations of conventional ultrasonic techniques,but require further validation.Differ-ent campaigns of experimental tests were performed,evaluating,by means of a probability of detection approach,the response of the technique to several artificial semi-elliptical flaws of increasing size and by considering two sensors characterized by different working frequencies.In contact,static tests allowed to assess the basic feasibility of the inspection technique and showed a linear response to defect size,saturating when defect width exceeded the rail web thickness.Dynamic tests allowed to introduce the effects of lift-off on signal responses.During all tests,the higher-frequency sensor outperformed the lower-frequency one.Finally,full-scale bogie tests on an indoor permanent track installation,comprehensive of defec-tive rails,confirmed the higher flaw detection rates of the higher-frequency sensor,with minimal detection failures despite occasional false alarms.EMATs showed encouraging results for in-motion rail inspection:with further technical development and optimization,this technique could enhance ultrasonic rail inspection by diagnostic trains.
文摘随着Web服务的快速发展,基于REST(Representational State Transfer)风格的Web Service越来越受到业界的关注。在实现RESTful Web Service的众多框架中,Rails完整实现了MVC并对RESTful Web Service的开发作了极大的封装和简化,使得开发人员用Rails实现RESTful Web Service变得容易。对RESTful Web Service特征和Rails框架结构进行了概述,分析了Rails实现RESTfulWeb Service的原理,在此基础上结合实例给出了基于Rails的RESTful Web Service以及RESTful Web Service客户端的开发步骤和方法,并且利用Ruby进行了实现。
文摘运用目前两种炙手可热的Web开发技术:AJAX和Ruby on Rails为WebGIS提供一个新的解决方案,AJAX技术作为一种新兴的网络技术比传统页面刷新模式具有更好的性能和友好的用户体验,不过在建立大量的Javascript的代码基础上的,本文通过对AJAX on Rails原理进行分析,运用Ruby on Rails的动态性和敏捷性使AJAX模式带来的程序量大、首页加载时间长的缺陷得到改善,进一步提高程序性能。在实现环节上,在该平台上结合使用Google Maps API,以GXmlHttp在Rails上实现了AJAX的WebGIS关键应用。
文摘Ruby on Rails是一个基于Ruby语言构建的全新Web应用程序架构,为Web应用程序开发提供了一种极其快捷的途径,正在和已经引起业界相当的兴趣.在给出了Ruby on Rails与轻量级J2EE架构Struts+Hibernate关键特性的基础上,从前端控制器、动作和模型,持久性框架三个方面对两种架构进行了比较.
文摘以SNS、BLOG等为代表的web2.0应用中,经常需要上传图片,而且要对图片进行缩放处理,得到缩略图。使用ruby on rails开发框架,通过attachment_Fu插件可以方便地实现所有这些功能。这大大提高了web应用的开发效率,符合用户对web2.0应用持续开发、持续改进、持续创新的要求。
文摘为大幅度缩短针对新的教学需求的计算机辅助教学系统的开发周期,同时高效的维护系统,研究了当前流行的Ruby On Rails框架技术。基于模型-视图-控制器（model-view-controller,MVC）设计模式进行系统开发,该系统可实现注册登录、作业提交、上机管理、上机测验、发送邮件、信息查询、作业检查、密码提醒等功能。测试结果表明了该软件的实用性。
