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BP网络微观与宏观弊病的研究 被引量:1
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作者 李桢 徐凌宇 《计算机工程与设计》 CSCD 北大核心 2006年第20期3779-3782,共4页
BP网络理论基础坚实,通用性强,是前向网络学习的主要模型,但是BP网络也存在一些公认的缺陷,这些缺陷一方面阻碍了BP网络的应用,另一方面也为研究BP网络指明了方向。实验发现这些缺陷产生于两个根本原因——微观的神经元病态和宏观的学... BP网络理论基础坚实,通用性强,是前向网络学习的主要模型,但是BP网络也存在一些公认的缺陷,这些缺陷一方面阻碍了BP网络的应用,另一方面也为研究BP网络指明了方向。实验发现这些缺陷产生于两个根本原因——微观的神经元病态和宏观的学习盲目性。经改进的BP网络划分学习阶段,在每个学习阶段结束后的阶段评估中检查和校正病态神经元,评估和调整BP网络的学习模式。实验表明改进的BP网络克服了部分缺陷,提高了性能。 展开更多
关键词 BP网络 神经元病态 学习盲目性 学习阶段 学习模式
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Analysis of clinicopathological and immunohistochemical features of 15 cases with olfactory neuroblastoma
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作者 Xianglan Ying Jun Lin Youping Yang 《The Chinese-German Journal of Clinical Oncology》 CAS 2009年第7期381-383,共3页
Objective:We studied the clinicopathological and immunohistochemical features of olfactory neuroblastoma(ONB).Methods:The clinic pathological data and immunohistochemical features of 15 cases with ONB were analyzed re... Objective:We studied the clinicopathological and immunohistochemical features of olfactory neuroblastoma(ONB).Methods:The clinic pathological data and immunohistochemical features of 15 cases with ONB were analyzed retrospectively,and the related literatures were reviewed.Results:The tumors were all located in the nasal cavity in 15 cases.According to Kadish's staging system,7 cases were in stage A,5 cases in stage B,and 3 cases in stage C.The morphological features showed small round or ovoid tumor cells divided into pieces or trabeculae by connective tissues which were rich in capillaries.The tumor cells had round or oval nuclei and fine chromatins and lack of cytoplasma.Flexner rosette and Homer-Wright rosette were found in some cases.Acidophilic fibrins were composed of cytoplasmic projection among tumor cells.All cases were positive for NSE,Syn,CgA,1 case was positive for Vimentin,2 cases were positive for S-100,while CKpan,LCA and HMB45 were all negative.Conclusion:ONB is a type of very rare malignant tumors,which could be diagnosed by pathology,and immunohistochemistry is helpful in the diagnosis and differential diagnosis. 展开更多
关键词 olfactory neuroblastoma (ONB) PATHOLOGY CLINIC IMMUNOHISTOCHEMISTRY
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