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TWGC-1型驼峰工频测长器调整与维护经验
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作者 王冀饶 廖永庆 《铁道通信信号》 北大核心 2001年第6期33-33,共1页
关键词 TWGC-1型驼峰 工频 设备 调整 维护 测长指标 精度
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Height centile curve for child and adolescents in Shaanxi province
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作者 尚磊 徐勇勇 +2 位作者 江逊 陈长生 侯茹兰 《Journal of Medical Colleges of PLA(China)》 CAS 2003年第2期129-133,共5页
Objective: It has been recommended that age-related centile curves of anthropometric indexes(such as height, weight) be used rountinly to evaluate the growth and development statues in children. Presented here is the ... Objective: It has been recommended that age-related centile curves of anthropometric indexes(such as height, weight) be used rountinly to evaluate the growth and development statues in children. Presented here is the age-related height centile curves for children aged 0-18 years in Shaanxi, China,1995. Methods: Data of the Shaanxi population were retrieved from The Third Nationwide Growth Survey to construct the age-related height centile curves. The LMS method was used for curve fitting; all analyses were carried out on the basis of different sexes through a special program for LMS(λ-median-coefficient) method which was devised by Cole TJ. Results: Centile curves for boys and girls, showing similar age-related features but girls'puberty coming two years earlier than boys'. The period of puberty growth increment was about 2 years longer for boys. At age 18, boys were taller than girls for about 14 cm. Compared with height standard of NCHS(national center of health statistics), Shaanxi children were taller than American children before 14 years for boys, 12 years for girls, but after 15 years for boys and 13 years for girls, Shaanxi children were shorter than American ones. At age 18, Shaanxi children was 5.6 cm for boys and 4.9 cm for girls shorter than NCHS. Shaanxi children's height increase range from 1958 to 1995 at the same age was 4.9-15.1 cm ,with the mean of 9.59 cm for boys, and 3.7-12.5 cm, with the mean of 8.38 cm for girls. Between 1958-1995, the increasing velocity every ten years were 2.57 cm for boys and 2.26 cm for girls, which indicated that the children have reached the optimum. Conclusion: By means of LMS method, we constructed age-related height centile curves for Shaanxi children aged 0-18 years, these height centile curves are the first one for the Chinese children. It can be used as a reference for assessing growth and development status of Shaanxi children aged 0-18 years. 展开更多
关键词 HEIGHT growth reference LMS method
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An efficient equivariant adaptive separation via independence algorithm for acoustical source separation and identification 被引量:2
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作者 CHENG Wei LU Jian Tao +1 位作者 GAO Lin ZHANG Jie 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2016年第12期1825-1836,共12页
To balance the convergence rate and steadystate error of blind source separation(BSS) algorithms, an efficient equivariant adaptive separation via independence(Efficient EASI) algorithm is proposed based on separating... To balance the convergence rate and steadystate error of blind source separation(BSS) algorithms, an efficient equivariant adaptive separation via independence(Efficient EASI) algorithm is proposed based on separating indicator, which was derived from the convergence condition of EASI, and can be used to evaluate the separation degree of separated signals. Furthermore, a nonlinear monotone increasing function between suitable step sizes and separating indicator is constructed to adaptively adjust step sizes, and forgetting factor is employed to weaken effects of data at the initial stage. Numerical case studies and experimental studies on a test bed with shell structures are provided to validate the efficiency improvement of the proposed method. This study can benefit for vibration & acoustic monitoring and control, and machinery condition monitoring and fault diagnosis. 展开更多
关键词 equivariant adaptive separation via independence adaptive step size separation indicator forgetting factor acoustical source separation and identification
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