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24 results on '"Liu, Zhongyao"'

9. Nondestructive measurement of an optical fiber refractive-index profile by a transmitted-light differential interference contact microscope

Author

Liu, Zhongyao, Dong, Xiaoman, Chen, Qianghua, Yin, Chunyong, Xu, Yuxian, and Zheng, Yingjun

Subjects
Optics -- Research, Astronomy, Physics
Abstract

A novel transmitted-light differential interference contrast (DIC) system is used for nondestructive measurement of the refractive-index profile (RIP) of an optical fiber. By means of this system the phase of a measured light beam can be modulated with an analyzer, and the phase distribution of a fiber is obtained by calculation of the various interference patterns. The measurement theory and structure and some typical applications of this system are demonstrated. The results of measuring RIPs in graded-index fiber are presented. Both the experimental results and theoretical analysis show that the system takes the advantage of high index resolution and of sufficient measurement accuracy for measuring the refractive index of the optical fiber. The system has strong ability to overcome environmental disturbance because of its common-path design. Moreover, one can use the system to measure the RIP along the fiber axis and acquire an image of the three-dimensional RIP of the fiber.

Published
2004

10. Step-height measurement by means of a dual-frequency interferometric confocal microscope

Author

Lin, Dejiao, Liu, Zhongyao, Zhang, Rui, Yan, Juqun, Yin, Chunyong, and Xu, Yi

Subjects
Optics -- Research, Astronomy, Physics
Abstract

A novel instrument, the dual-frequency interferometric confocal microscope (DICM), which facilitates the measurement of step features, is investigated. It combines the advantages of the high resolution (subnanometer) of heterodyne interferometry and the relatively large measurement range (~5 [micro]m) of confocal microscopy. The axial response curves of the confocal microscopy system are compared in experiments in which microscopic objects with various numerical apertures and magnifications are used. The results prove that the variation in light intensity is enough to permit discrimination of different orders of interference fringes. The DICM has been successfully utilized to measure the step height of a standard mask, and the experimental results agree well with those measured by scanning probe microscopes. The results also show that the system has good repeatability, with a maximum deviation of 5 nm.

Published
2004

13. Power Load Forecasting Model Based on Knowledge Discovery for Heilongjiang Province

Author

Dou Quansheng, Yang Bin, Shi Zhongzhi, and Liu Zhongyao

Subjects
Electric power system, Knowledge extraction, Computer science, Power load, Load modeling, Load forecasting, Data mining, Software system, Power grid, computer.software_genre, computer, Industrial engineering, Field (computer science)
Abstract

Load forecasting is a traditional research field of power system. This paper analyzed the meteorological and economic characteristics of Heilongjiang Province, and put forward the load forecasting model based on knowledge discovery. First of all, generate the preliminary prediction curve by traditional method, and extract related rules from the historical load and meteorological data, then update the preliminary prediction curve using these rules, and generate the final prediction curve. The model has been used in software system of load forecasting for Heilongjiang power grid Co, Ltd., and obtained desired results.

Published
2009

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