In this paper,a class of fractional order Schrödinger-Poisson systems with singular terms and double critical exponents is considered.The problem that the singular term causes the functional to be nondifferentiable at zero is solved by a perturbation method,and the ex-istence of two positive solutions of the system is obtained by using the critical point theory of non-smooth generalized functions and mountain lemma.
Basic characteristics of high-speed railway pantograph system,it is required to en-sure the stability and safety of pantograph contact during the operation of electric locomotive,the characteristic is that the current transmission the pantograph is stable,real-time monito-ring and storage of parameters,the mechanical vibration error of the pantograph is small and the operation curve adjustment is fast.Firstly,this paper analyzes the design indicators and curve characteristics of the operating parameters of the high-speed pantograph system,propo-ses the structural characteristics of mechanical vibration of pantograph.Secondly,this paper analyzes the principle of mechanical vibration of the pantograph,as well as the parameter pre-diction models of DMC,establishes a flowchart based on open-loop predictive control algo-rithm.DMC(Dynamic Matrix Control)is an open-loop control for clustering optimization curves.The mechanism is to use the dynamic parameters of the pantograph system as the ref-erence input,the main optimization strategy is to detect the mechanical vibration online and adjust the curve.The quantitative relationship between algorithm and system performance guides the debugging of design parameters in application.Finally,through the field instru-ment detection and analysis of four groups of bow net experiments,theoretical simulation comparison,it is concluded that the DMC open-loop control method is superior to GPC(gen-eralized predictive control)closed-loop feedback control effect has the best solution.
为了使用计算机辅助语言学习系统(Computer Aided Language Learning,CALL)帮助藏族学生在学习普通话时及时发现和纠正错误发音,构建了一个适用于藏族学生普通话发音评估的语料库.从声母、韵母及声调的概念来比较分析藏语学生的普通话语音特征,归纳出藏族学生易混淆的声、韵、调,并进行文本语料的设计和语音语料的录制.对录制的音频文件用国际通用标注软件PRAAT进行分层标注,对标注好的语料进行分类编号.实验结果证明,该语料库可以及时纠正藏族学生学习普通话时的错误发音.
作为应用型本科院校,在教学中以培养适应性强、学习能力高、竞争能力强和协作能力好的技能型人才为目标,实现高校课堂改革.结合教学实践,探讨了积极教学法在高校课堂中的实践过程,通过构建良好的学习环境,以及在课堂实施过程中采用有导向性提问、分组活动、基于学习任务单的自主学习和改良版头脑风暴等教学方法,使学生从传统教学的被动接受变为积极参与到形式多样的教学活动中进行高效学习,真正做到"以学生为主体,以教师为主导".采用多元化课程评价体系,注重过程考核,充分调动了学生学习的积极性和参与度.相比传统授课模式,积极教学法使学生学习的主动性有了明显提高,尤其是学习能力方面有了显著增强,整体教学质量得到了极大提升.
目标用户近邻的计算选择与评分预测是决定协同过滤推荐算法推荐质量与准确度的关键步骤.传统的目标近邻选择与评分预测方法未考虑用户的个人评价尺度或评价习惯,导致近邻选择不准确,影响最终的推荐结果.为了提高目标用户近邻准确度量选取的问题,本文提出基于聚类与差异协调的协同过滤推荐算法,采用结合时间权重与聚类的方式筛选出目标的近邻用户,通过评价差异因子协调评价差异完成最终预测推荐.实验结果表明,该算法能够提高推荐系统的推荐质量和准确度.
