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波涌灌溉设备 被引量:2
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作者 谢崇宝 《农业机械》 2000年第10期24-26,共3页
波涌(涌流或间歇)灌溉技术于20世纪70年代末起源于美国,并在其西部地区得到较快的推广应用。该技术自80年代初引入我国后,已先后在波涌灌水技术的节水机理、地表水流特性和田面土壤入渗特性等基础理论研究上取得了较大进展。近年来,在... 波涌(涌流或间歇)灌溉技术于20世纪70年代末起源于美国,并在其西部地区得到较快的推广应用。该技术自80年代初引入我国后,已先后在波涌灌水技术的节水机理、地表水流特性和田面土壤入渗特性等基础理论研究上取得了较大进展。近年来,在田间应用研究方面,特别是波涌灌溉设备的研制取得了重大突破,为波涌灌水技术在我国的应用提供了设备支撑条件。 展开更多
关键词 波涌灌溉设备 性能指标使用 美国 中国
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Region Pair Grey Difference Classifier for Face Detection 被引量:1
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作者 欧凡 刘冲 欧宗瑛 《Transactions of Tianjin University》 EI CAS 2010年第2期118-122,共5页
A new kind of region pair grey difference classifier was proposed. The regions in pairs associated to form a feature were not necessarily directly-connected, but were selected dedicatedly to the grey transition betwee... A new kind of region pair grey difference classifier was proposed. The regions in pairs associated to form a feature were not necessarily directly-connected, but were selected dedicatedly to the grey transition between regions coinciding with the face pattern structure. Fifteen brighter and darker region pairs were chosen to form the region pair grey difference features with high discriminant capabilities. Instead of using both false acceptance rate and false rejection rate, the mutual information was used as a unified metric for evaluating the classifying performance. The parameters of specified positions, areas and grey difference bias for each single region pair feature were selected by an optimization processing aiming at maximizing the mutual information between the region pair feature and classifying distribution, respectively. An additional region-based feature depicting the correlation between global region grey intensity patterns was also proposed. Compared with the result of Viola-like approach using over 2 000 features, the proposed approach can achieve similar error rates with only 16 features and 1/6 implementation time on controlled illumination images. 展开更多
关键词 face detection region pair grey feature region grey pattern correlation machine learning
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