Computer simulation of active suspension based on the full-vehicle model

The current method to solve the problem of active suspension control for a vehicle is often dealt with a quarter-car or half-car model.But it is not enough to use this kind of model for practical applications.In this paper,based on considering the influence of factors such as,seat and passengers a MDOF(multi-degree-of-freedom)model describing the vehicle motion is set up.The MODF model,which is 8DOF of four independent suspensions and four wheel tracks,is more applicable by comparison of its analysis result with some conventional vehicle models.Therefore,it is more suitable to use the 8DOF full-car model than a conventional 4DOF half-car model in the active control design for car vibration.Based on the derived 8DOF odel,a controller is designed by using LQ(linear quadratic)control theory,and the appropriate control scheme is selected by testing various performance indexes.Computer simulation 8is carried out for a passenger car running on a road with step disturbance and random road disturbance expressed by Power Spectral Density(PSD).Vibrations corresponding to ride comfort are derived under the foregoing road disturbances.The response results for uncontrolled and controlled system are compared.The response of vehicle vibration is greatly suppressed and quickly damped.which testifies the effect of the active suspenson.The results achieved for various controllers are compared to invesigate the influence of different control schemes on the control effect.     

主题关联性阅读模式的建构——兼论语境参数论与TEM-8语篇阅读

探讨了语篇生成之主题关联性机制,并从语境参数论出发,结合TEM-8阅读考试真题分析阐述了建立主题关联性阅读模式的可行性与重要性,强调语境参数对于语篇阅读理解的重要意义。这是提高英语语篇阅读效率与TEM-8阅读考试成绩的有效途径。     

叠加势V（r）=B8r^8＋B7r^7＋B6r^6＋B5r^5＋B4r^4＋B3r^3＋B2r^2＋B1r schrodinger方程的解析解

根据波函数的有限性和叠加势函数的渐近性质,通过待定波函数的设定,得到势函数表示为V（r）=B8r^8＋B7r^7＋B6r^6＋B5r^5＋B4r^4＋B3r^3＋B2r^2＋B1r的径向schrdinger方程的精确的能量本征值和本征波函数.     

The importance of adjusting for pupil background in school value-added models: A study of Progress 8 and school accountability in England

In the UK, USA and elsewhere, school accountability systems increasingly compare schools using value-added measures of school performance derived from pupil scores in high-stakes standardised tests. Rather than naïvely comparing school average scores, which largely reflect school intake differences in prior attainment, these measures attempt to compare the average progress or improvement pupils make during a year or phase of schooling. Schools, however, also differ in terms of their pupil demographic and socioeconomic characteristics and these factors also predict why some schools subsequently score higher than others. Many therefore argue that value-added measures unadjusted for pupil background are biased in favour of schools with more ‘educationally advantaged’ intakes. But others worry that adjusting for pupil background entrenches socioeconomic inequities and excuses low-performing schools. In this article we explore these theoretical arguments and their practical importance in the context of the ‘Progress 8’ secondary school accountability system in England, which has chosen to ignore pupil background. We reveal how the reported low or high performance of many schools changes dramatically once adjustments are made for pupil background, and these changes also affect the reported differential performances of regions and of different school types. We conclude that accountability systems which choose to ignore pupil background are likely to reward and punish the wrong schools and this will likely have detrimental effects on pupil learning. These findings, especially when coupled with more general concerns surrounding high-stakes testing and school value-added models, raise serious doubts about their use in school accountability systems.     

基于3G的高校数字教育资源系统的设计与实现

文章针对高校数字教育资源的共享与应用不足问题,设计出一种高安全性、高信息集成度的综合解决方案。通过对目前各大高校的数字教育资源系统的了解,设计并开发出通用接口式J2ME客户端和J2EE服务器端,实现了无线客户端与服务器端的动态分离,只需修改服务器端信息访问接口,便可实现系统跨校移植。     

华利烟花厂爆炸事故分析及安全措施研究

近年来,我国烟花爆竹爆炸事故频频发生,造成重大的人员伤亡和惨重的经济损失。究其原因,非法生产、经营烟花爆竹是发生爆炸事故的主要原因。为减少烟花爆竹安全事故的发生,研究分析烟花爆竹行业的有效监管办法,本文以黑龙江伊春烟花厂爆炸事故为例,分析事故原因,主要从政府监管的方面,针对管理上的漏洞、政令不通、监管不力、从业人员(主要是业主)安全意识淡薄等几个因素进行了探讨,着重讨论了烟花爆竹行业安全管理的可行途径。对烟花爆竹行业的安全管理提供一些有益的参考。     

基于ASP.NET的移动通讯渠道管理系统设计

以.NET为软件开发平台,以ASP.NET为软件开发框架,以ORACLE为数据库服务器,以windows自带的Internet Explorer浏览器作为客户端,以成熟的企业管理思想为指导,结合优秀的软件开发技术设计了一套移动通讯渠道管理系统,该系统的实现优化了移动通讯企业的管理流程,提高了移动通讯企业行业竞争力。     

PASSIM8K接装机滤嘴烟支切割鼓轮尘槽改进

通过对PASSIM接装机最后切割鼓轮尘槽进行改进,利用鼓轮体内部的负压吸风及时将切割尘末吸除,不但使成品滤嘴烟支切口光滑平整,保证了烟支的外观质量,而且也减少了打刀、同步齿形带断裂损坏等问题,减少了因频繁清理而停机的次数和维修时间,提高了设备的有效作业率.在维护和保养最后切割部件时也更加方便,节时省力.     

人机界面系统输入模块的控制方法

介绍了一种基于P89C51单片机的触摸式人机界面系统中作为系统输入的电阻触摸屏,介绍了8x15行列式电阻触摸屏的结构、工作方式及接口电路的设计,并详细介绍了控制方法。     

普通高校英语专业高年级学生写作困境探析

普通高校英语专业高年级学生仍然面临着种种写作困境,这是各种因素综合作用的结果。从客观层面来说,教师必须灵活调整教学策略。教师只有因材施教、对症下药,学生才能不断攻破他们在写作过程中的薄弱环节,从而使高年级阶段的TEM8写作测试单项成绩迈上一个新台阶。