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局部区域描绘子和SOM聚类算法在LED管芯计数中的应用 被引量:1
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作者 唐亮 刘烨 陈雁秋 《计算机应用与软件》 CSCD 北大核心 2012年第10期11-13,21,共4页
传统的图像处理算法往往受到光照干扰、角度变化、噪声等因素的影响,无法得到准确快速的识别结果。提出一种新颖的局部区域描绘子刻画目标点群的灰度值特征,并结合自组织映射SOM聚类,对发光二极管(LED)芯片中的管芯区域进行高效识别和... 传统的图像处理算法往往受到光照干扰、角度变化、噪声等因素的影响,无法得到准确快速的识别结果。提出一种新颖的局部区域描绘子刻画目标点群的灰度值特征,并结合自组织映射SOM聚类,对发光二极管(LED)芯片中的管芯区域进行高效识别和准确计数。实验结果表明,该方法能够对LED管芯进行有效的识别计数,准确度高、鲁棒性好。 展开更多
关键词 局部区域描绘 SOM聚类 LED管芯计数 过检测策略
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基于非局部区域关联和概率建模的虹膜识别方法 被引量:1
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作者 李培华 吴国龙 马宏伟 《电子学报》 EI CAS CSCD 北大核心 2014年第12期2379-2385,共7页
传统的虹膜识别方法主要提取和匹配局部区域特征,忽略了距离较远区域(即非局部区域)特征之间的相关性.基于序特征的方法通过高斯低通滤波器提取区域的平均灰度值并对不同区域进行大小比较,但是这种方法并不适用于用概率密度描述区域统... 传统的虹膜识别方法主要提取和匹配局部区域特征,忽略了距离较远区域(即非局部区域)特征之间的相关性.基于序特征的方法通过高斯低通滤波器提取区域的平均灰度值并对不同区域进行大小比较,但是这种方法并不适用于用概率密度描述区域统计特性的情况.本文提出一种新颖的虹膜识别方法解决传统方法的不足.该方法在用空间-相位联合分布表示局部区域纹理特征的基础上,通过将位于距离较远图像区域的特征进行连接得到非局部区域关联描述子表达区域之间的关联特性.论文着重研究了两区域和三区域关联对虹膜识别性能的影响.在虹膜匹配时,考虑非局部区域关联描述子的有效性以排除遮挡、高亮和噪声等干扰因素的影响,允许非局部区域关联描述子进行整体微小平移以建模虹膜纹理的非刚性形变,最后用一种鲁棒的扩散直方图距离比较关联描述子之间的差异.论文在三个公开的虹膜数据库中进行了虹膜验证和虹膜识别实验,结果表明所提出的方法在性能上优于同类方法. 展开更多
关键词 虹膜验证和识别 空间-相位联合分布 局部区域关联描述
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CT影像识别的卷积神经网络模型 被引量:14
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作者 管姝 张骞予 +2 位作者 谢红薇 强彦 程臻 《计算机辅助设计与图形学学报》 EI CSCD 北大核心 2018年第8期1530-1535,共6页
针对传统分类方法分割精度低、特征提取耗时等问题,构建一个适用于CT肺结节良恶性分类的卷积神经网络模型.首先确定网络深度、卷积核数目和卷积核大小等参数,构建卷积神经网络初始模型;然后选择激活函数类型、学习率和学习率衰减策略等... 针对传统分类方法分割精度低、特征提取耗时等问题,构建一个适用于CT肺结节良恶性分类的卷积神经网络模型.首先确定网络深度、卷积核数目和卷积核大小等参数,构建卷积神经网络初始模型;然后选择激活函数类型、学习率和学习率衰减策略等训练参数;最后提出对感兴趣区域划分局部子区域的方式增强样本进行训练.在LIDC-IDRI数据集上进行实验的结果表明,准确率、特异性、敏感性及AUC值分别达到92.50%,0.91,0.94和0.93;对恶性结节的识别能力明显优于其他网络模型. 展开更多
关键词 卷积神经网络 肺部CT 图像分类 局部子区域
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Colorectal cancer and 18FDG-PET/CT:What about adding the T to the N parameter in loco-regional staging? 被引量:5
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作者 Pier Paolo Mainenti Delfina Iodice +5 位作者 Sabrina Segreto Giovanni Storto Mario Magliulo Giovanni Domenico De Palma Marco Salvatore Leonardo Pace 《World Journal of Gastroenterology》 SCIE CAS CSCD 2011年第11期1427-1433,共7页
AIM:To evaluate whether FDG-positron emission tomography(PET)/computed tomography(CT)may be an accurate technique in the assessment of the T stage in patients with colorectal cancer.METHODS:Thirty four consecutive pat... AIM:To evaluate whether FDG-positron emission tomography(PET)/computed tomography(CT)may be an accurate technique in the assessment of the T stage in patients with colorectal cancer.METHODS:Thirty four consecutive patients(20 men and 14 women;mean age:63 years)with a histologically proven diagnosis of colorectal adenocarcinoma and scheduled for surgery in our hospital were enrolled in this study.All patients underwent FDG-PET/CT preoperatively.The primary tumor site and extent were evaluated on PET/CT images.Colorectal wall invasion was analysed according to a modified T classification that considers only three stages(≤T2,T3,T4).Assessment of accuracy was carried out using 95%confidence intervals for T.RESULTS:Thirty five/37(94.6%)adenocarcinomas were identified and correctly located on PET/CT images.PET/CT correctly staged the T of 33/35 lesions identified showing an accuracy of 94.3%(95%CI:87%-100%).All T1,T3 and T4 lesions were correctly staged,while two T2 neoplasms were overstated as T3.CONCLUSION:Our data suggest that FDG-PET/CT may be an accurate modality for identifying primary tumor and defining its local extent in patients with colorectal cancer. 展开更多
关键词 Cancer COLORECTAL Positron emission tomography/computed tomography STAGING
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Emergence of target waves in neuronal networks due to diverse forcing currents 被引量:4
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作者 MA Jun WANG ChunNi +2 位作者 YING HePing WU Ying CHU RunTong 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2013年第6期1126-1138,共13页
The electric activities of neurons could be changed when ion channel block occurs in the neurons.External forcing currents with diversity are imposed on the regular network of Hodgkin-Huxley(HH) neuron,and target wave... The electric activities of neurons could be changed when ion channel block occurs in the neurons.External forcing currents with diversity are imposed on the regular network of Hodgkin-Huxley(HH) neuron,and target waves are induced to occupy the network.The forcing current I1 is imposed on neurons in a local region with m 0 ×m 0 nodes in the network,neurons in other nodes are imposed with another forcing current I2.Target wave could be developed to occupy the network when the gradient forcing current(I1-I2) exceeds certain threshold,and the formation of target wave is independent of the selection of boundary condition.It is also found that the developed target wave can decrease the negative effect of ion channel block and suppress the spiral wave,and thus channel noise is also considered.The potential mechanism of formation of target wave could be that the gradient forcing current(I1-I2) generates quasi-periodical signal in local area,and the propagation of quasi-periodical signal induces target-like wave due to mutual coupling among neurons in the network. 展开更多
关键词 target wave network of neuron channel block HODGKIN-HUXLEY
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