集团抽样检验方法

提出了对不合格率低的产品进行集团检验方法,提出了一次抽样、二次抽样的检验方法,并对样 本量和临界值的选取方法进行了分析.     

软件无线电在宽带数字仪器仪表中的应用

根据软件无线电的研究成果,采用抽取、内插等数字信号处理方法,将频域带通采样变换方法应用于宽带数字仪器仪表,从而可大大降低对A/D转换器的要求。     

基于分层抽样的垃圾减量分类效果研究

针对垃圾减量分类过程中基础数据分项及颗粒度是否足够等问题进行理论的探讨,综合利用了分层抽样、回归分析等方法,得出了深圳市垃圾减量分类活动的效果.参考台湾的垃圾减量分类措施,建立干预分析模型.通过预测未来深圳5年的人口变化以及城市生活垃圾人均日清运量得到深圳市垃圾减量分类后的最好结果与最坏结果.建议政府加强垃圾分类的推行力度并增加垃圾分类宣传推广的投入.     

延时叠加工频谐波消除系统设计与实验

针对全波核磁共振信号中的噪声,尤其是最接近拉莫尔频率的工频谐波噪声干扰,影响核磁共振信号的采集及测试结果。设计了延时采样、叠加抵消的消噪方法,理论计算了对同一位置的信号相差半个最接近拉莫尔频率的工频谐波信号周期的两组信号,分别提取并叠加,可以消除拉莫尔频率附近的工频谐波噪声的算法。仿真结果表明,采用设计的消噪方法,信噪比可以提高6.9 dB。采用实际电路测试信号,实测结果与仿真结果对比基本一致。结果表明,该设计可以消除最接近拉莫尔频率处的工频谐波噪声,从而有效的提取核磁共振信号,保证了反演解释的正确性和准确性。     

非线性回归方程 Y =aXb+ ε 参数的贝叶斯估计与应用

对于回归方程参数的估计,常采用经典统计方法。近年来,伴随着计算机技术的快速发展,贝叶斯统计获得了广泛应用。本文利用贝叶斯统计对非线性回归方程Y=aX^b＋ε进行参数估计,并进行了实例演示,验证了该方法的有效性。     

截面相似性零件的自适应测点规划研究

针对整个模型统一尺度规划和曲面间的衔接处理困难问题,提出“曲面模型-三角网格模型-截面线-点集-测点集”的规划策略,实现基于曲率特性的自适应测点规划。通过将数字化设计模型转换成统一粒度的密集三角网格模型,实现复杂型面的一致性描述;进而利用三角网格的拓扑信息,提取截面线;在截面线曲率估算的基础上,通过均分曲线质量进行测量点的自适应规划。结果表明,该研究能以较少的测点反映加工误差。     

Introducing the DYNAMICS framework of moment-to-moment development in achievement motivation

This article introduces a new theoretical and psychometric framework describing moment-to-moment development and inter-dependencies of achievement motivation in terms of the situated expectancy-value theory, by introducing dynamical systems concepts into this line of research. As a first empirical example of a study using this framework, we examined whether task values, costs, and success expectancies measured in a learning situation (time point t) predicted themselves and each other at the next situation (t + 1; 27 min later) within a weekly university lecture.Situational task values, expectancies, and costs were assessed using the experience sampling method in 155 university teacher training students during weekly lectures for one semester, with three surveys during each weekly lesson. Data were analyzed with multilevel cross-lagged structural equation models.There were significant auto-regressions from one learning situation to the next in success expectancies and effort costs, but not in intrinsic, utility, or attainment value nor emotional or opportunity costs. There were no significant cross-lagged effects from one situation to the next in any of the measured situated expectancy-value components.As a framework to integrate dynamical systems concepts into the research on situated learning motivation, we expect the proposed DYNAMICS framework to have a substantial impact on further theory development.