双参数Bézier曲线的升二次扩展

本文以二次Bernstein基函数为例,首次提出了含双参数基函数的新扩展——αβQ—Bern-stein基函数,此类基函数具有新的特点,即基函数的扩展次数一次性升高两次,且包含了二次多项式和带一个参数的三次多项式基函数的所有性质。基于这组基函数定义了αβQ—Bézier曲线,该曲线也含有参数,具有形状可调性,当α与β取某些值时曲线能达到C4连续或在某个端点处C0连续。最后与含两个参数的升一次Bézier曲线进行比较,该曲线具有调节范围广、灵活性更强的优势。     

Motivational bases of the public goods problem.

Compared 2 motivational bases for not contributing to a public good, desire to "free ride" (or greed) and fear of being a "sucker," among 110 Japanese undergraduates. It was hypothesized that these 2 types of motivation would be activated under different situations. When a public good was provided conjunctively, fear would have a strong effect but greed would not; when a public good was disjunctively provided, greed would have a strong effect but fear would not. In addition, it was predicted that the greater mutual trust existing among friends would make them contribute more than strangers would in the conjunctive condition but would make no difference in the disjunctive condition. Three types of production rules, in which a public good was conjunctively, disjunctively, or additively produced on the basis of members' contributions, were experimentally created. Half of the groups in each condition consisted of total strangers, and the other half consisted of friends. The hypotheses were supported when the size of the public good (bonus points) was relatively large. Also, Ss responded similarly in the conjunctive condition and in the additive condition. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

不确定离散系统的鲁棒Gl2滤波器设计

对于凸多面体不确定离散系统,研究了满足误差估计系统鲁棒稳定且满足一定Gl₂性能指标的线性全阶稳定滤波器设计方法.分别给出了确定性和不确定性离散系统具有Gl₂性能的线性矩阵不等式（linear matrix inequality, LMI)充要条件和充分条件.在此基础上,通过使用滤波器参数化方法,分别推导出了以LMI描述的确定性和不确定性系统的Gl₂滤波器存在的充要条件和充分条件,进而可以使用LMI凸优化程序求解滤波器.通过对算例的计算,结果表明,在噪声信号为独立范数有界情况下,鲁棒Gl₂滤波比H_∞滤波具有更少的保守性.     

基于PCC-RBF网络的风电功率短期预测方法

风电功率预测对风电场安全平稳运行、电网调度具有重要意义。针对风电功率短期预测指标选择不合理、预测精确度偏低的问题,提出一种基于皮尔逊相关系数(PCC)和径向基函数(RBF)神经网络的风电功率短期预测方法。该方法利用PCC筛选出与风电功率密切相关的3个指标,即电流、温度、风速,然后以这3个指标作为预测模型的输入对风电功率进行RBF样本训练与短期预测。试验结果表明,所提的预测模型预测误差更小,预测精度更高,能够满足风电功率短期预测的要求,具有广泛的应用前景。     

西宁特钢连铸机技术改造

对西钢新建生产线五机五流小方坯连铸机改造进行了综述.连铸机优良的装备为整条生产线向品种化、规模化、高效化方向快速发展奠定了基础.     

矢功率谱与RBF网络结合在旋转机械故障诊断中的应用

与传统功率谱相比,矢功率谱融合了多通道的能量信息,反映的信息更全面.径向基函数网络具有良好的推广能力和分类能力.基于此,本文结合矢功率谱和径向基函数网络,提出了一种新的故障识别方法,该方法以矢功率谱为特征向量,径向基函数网络为分类器.并以转子裂纹、转子不对中、油膜涡动为例进行实验研究,实验结果表明,该方法是有效的.     

钢铁酸洗时氢致裂开危险性检测新技术的研究

研究了一种新型的原子氢渗透速率测量传感器在酸洗液中的测量信号与A3钢在相应体系中的强度/脆性之间的对应关系,为发展钢铁酸洗除锈除垢时在线检测氢致腐蚀裂开危险性的智能化新技术,提供了软件设计的部分关键参数与判据。     

50年来辽宁省不同等级舒适日数演变及空间区划分析

根据1964—2015年辽宁省23个气象站点的逐日平均气温、相对湿度及平均风速资料,采用人体舒适度指数法计算人体舒适度指数,在季尺度上分析辽宁省不同等级舒适日数演变情况及典型旅游城市最佳旅游期;运用旋转经验正交函数分解法(REOF),分析人体舒适度指数季尺度空间变化特征,并应用ArcGIS软件进行舒适区域划分。结果表明:①辽宁省多年平均冷不舒适日数呈降低趋势,舒适日数呈增加趋势,热不舒适日数也呈微弱增加趋势;舒适程度夏季＞秋季＞春季＞冬季;②除冬季外5座典型旅游城市均适宜旅游,夏季为最佳旅游期;其中,沈阳、本溪更适宜春季旅游,大连更适宜秋季旅游。③辽宁省四季舒适度变化情况可大致划分为辽西、辽中、辽东三个区域,具体划分情况随季节有相应变化,总体舒适度由辽宁东部向西部逐渐递减。     

A new approach to the epsilon expansion of generalized hypergeometric functions

Assuming that the parameters of a generalized hypergeometric function depend linearly on a small variable ε$\epsilon$, the successive derivatives of the function with respect to that small variable are evaluated at ε=0$\epsilon =0$ to obtain the coefficients of the ε$\epsilon$-expansion of the function. The procedure, which is quite naive, benefits from simple explicit expressions of the derivatives, to any order, of the Pochhammer and reciprocal Pochhammer symbols with respect to their argument. The algorithm may be used algebraically, irrespective of the values of the parameters. It reproduces the exact results obtained by other authors in cases of especially simple parameters. Implemented numerically, the procedure improves considerably, for higher orders in ε$\epsilon$, the numerical expansions given by other methods.