期刊文献+
共找到2篇文章
< 1 >
每页显示 20 50 100
浮动平底推杆-盘形凸轮组合机构的第Ⅰ类机构综合问题 被引量:3
1
作者 常勇 林荣富 李延平 《中国机械工程》 EI CAS CSCD 北大核心 2015年第12期1584-1595,共12页
提出"预设凸轮轴心O1+等距/网格/离散化+校核+取舍"的新型求解策略和路线,通过建立"固定、浮动坐标系"并引入"支撑函数法"、"瞬时区域套"、"经济搜索区域"及"等距/网格/离散化&... 提出"预设凸轮轴心O1+等距/网格/离散化+校核+取舍"的新型求解策略和路线,通过建立"固定、浮动坐标系"并引入"支撑函数法"、"瞬时区域套"、"经济搜索区域"及"等距/网格/离散化"等概念和方法,研究了满足ρ>0、α≤[α]∩α≤[α]r和ρ>0、α≤[α]∩α≤[α]r等单纯或组合条件下凸轮轴心O1的求解原理、解析表达、"位置区域Πρ、Π[α]和Πρ∩[α]"及其形态特征,提出了搜索求解的思路和方法,推导出了平底工作段及其长度、总长度的求解确定方法,揭示出"位置区域Π[α]和Πρ∩[α]"的"类等腰三角形"、"收缩聚敛性"、"脊点O*1/脊线{O*1}存在性"和"最优脊点O**1存在性"等规律特性,得到"凸轮轴心O1优选(非劣)解集"、"最优凸轮轴心O*1opt和O**opt"等重要的关键性结论,较圆满地解决了浮动平底推杆-盘形凸轮组合机构的第Ⅰ类机构综合问题。 展开更多
关键词 等距/网格/离散化 浮动坐标系 支撑函数 瞬时区域 经济搜索区域 脊点/脊线
下载PDF
Estimation of Demographic Statistics in the Cambodia Socio-Economic Survey (CSES) 2004-2012
2
《Journal of Mathematics and System Science》 2014年第2期111-115,共5页
Since 2007 the CSES is the only source that every year has provided estimates of Cambodian demographic statistics such as population and household sizes by geographical region, sex, marital status and ethnicity. This ... Since 2007 the CSES is the only source that every year has provided estimates of Cambodian demographic statistics such as population and household sizes by geographical region, sex, marital status and ethnicity. This "work" describes the methodology used to make the estimates consistent with Census projections taking into account change in household sizes. The methods are based on assumptions and they will adjust the weights of the survey. The assumptions need to be evaluated continuously and this presentation is the first documentation and evaluation. Using time series of some key statistics, the work also presents and discusses the demographic development in Cambodia. A future decision if the methodology in the CSES has to be completely changed or just updated must be made when the Inter-censual result from 2013 are available. 展开更多
关键词 CONSISTENCY census projections weighting method.
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部