jgg     2012 32 (1):  127-131    ISSN: 0412-1961  CN: 21-1139/TG RESEARCH ON ALGORITH OF WAVELET NEURAL NETWORK FOR FORECASTING LENGTH OF DAY Wang Yupu ;and Lü Zhiping Institute of Surveying and Mapping, Information Engineering University, Zhengzhou 450052 Received: 1900-01-01  Revised: 1900-01-01  Online: null Supporting info null