《文献计量学指数增长规律.ppt》由会员分享,可在线阅读,更多相关《文献计量学指数增长规律.ppt(8页珍藏版)》请在金锄头文库上搜索。
1、年代t(年)20002001200220032004200520062007200820092010论文量n(篇)69162021252531347069求相应的逐年分布及累积分布函数检索主题:信息检索策略(一)逐年分布函数因为逐年分布公式对其取对数则有:根据最小二乘法,求直线方程已知公式年代t(年)2000200120022003200420052006200720082009论文量n(篇)691620212525313470123456789101.792.202.7733.043.223.223.433.534.251.794.398.321.9815.2219.3122.5327.47
2、31.7442.28149162536496481100(1+2+3+4+5+6+7+8+9+10)=5.5=(6+9+16+20+21+25+25+31+34+70)=3.04则,=0.21830.2516.723.04-0.218*5.5=1.841则,=9.01那么,逐年分布函数则为:年代t19992000200120022003200420052006200720082009论文量n9691620212525313470论文积累量N41475672921131381631942282980123456789103.854.034.284.524.734.935.095.275.435.73.858.0512.8318.0923.6429.5635.6642.1448.8656.97149162536496481100则,=41.33则,逐年累积分布函数为: