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基于依存特征的汉语框架语义角色自动标注 被引量:8
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作者 王智强 李茹 +2 位作者 阴志洲 刘海静 李双红 《中文信息学报》 CSCD 北大核心 2013年第2期34-40,共7页
语义角色标注是浅层语义分析的一种实现方式。目前汉语框架语义角色自动标注一般被看作以词为基本标注单元的序列标注问题,而已有研究中仅在词、词性层面来选取特征,标注结果并不理想。该文利用树条件随机场模型,通过在词、词性层面特... 语义角色标注是浅层语义分析的一种实现方式。目前汉语框架语义角色自动标注一般被看作以词为基本标注单元的序列标注问题,而已有研究中仅在词、词性层面来选取特征,标注结果并不理想。该文利用树条件随机场模型,通过在词、词性层面特征的基础上依次加入不同类型的依存特征,研究依存特征对汉语框架语义角色标注的影响。实验设置了8类,共24种特征模板,结果显示,加入依序特征的最优模版使标注结果的F值提高近3%,特别是对较长框架语义角色的标注结果有较好的改善。 展开更多
关键词 框架语义角色 依存特征 T-CRF模型
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利用自适应图像块划分的图像噪声强度估计 被引量:5
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作者 傅鹏 孙权森 纪则轩 《计算机辅助设计与图形学学报》 EI CSCD 北大核心 2015年第8期1475-1482,共8页
传统的基于图像块划分的噪声强度估计方法通常先将图像划分为若干规则矩形图像块,并利用其中平滑的图像块进行噪声强度计算.然而当图像的结构信息比较丰富时,传统的方法往往会出现较大的偏差.为了解决该问题,提出一种基于自适应图像块... 传统的基于图像块划分的噪声强度估计方法通常先将图像划分为若干规则矩形图像块,并利用其中平滑的图像块进行噪声强度计算.然而当图像的结构信息比较丰富时,传统的方法往往会出现较大的偏差.为了解决该问题,提出一种基于自适应图像块划分的图像噪声强度估计方法.首先结合图像的空间邻域信息,将含噪图像划分为若干贴合图像局部边缘、纹理等结构信息的自适应图像块;然后根据所划分图像块的统计特性,通过散点图统计法选取出平滑的自适应图像块;最后利用平滑自适应图像块估计图像的噪声强度.实验结果表明,相比于已有的噪声估计方法,该方法在针对不同噪声强度、不同复杂程度的图像时更加准确和稳定. 展开更多
关键词 噪声估计 高斯噪声 自适应图像块 空间邻域信息 相似性度量
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龙虾胃肠神经系统的数值分析 被引量:4
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作者 刘深泉 L.Song 《生物物理学报》 CAS CSCD 北大核心 2004年第3期217-224,共8页
利用抑制神经系统的WinnerLessCompetition(WLC)模型,通过数值方法分析Mulloney型龙虾胃肠神经系统神经元的电位发放,得到胃研磨囊和幽门神经系统中各个神经元的电位发放和系统的节律变化。结果表明,胃研磨系统内神经元的发放规律显示... 利用抑制神经系统的WinnerLessCompetition(WLC)模型,通过数值方法分析Mulloney型龙虾胃肠神经系统神经元的电位发放,得到胃研磨囊和幽门神经系统中各个神经元的电位发放和系统的节律变化。结果表明,胃研磨系统内神经元的发放规律显示两侧牙齿和中间牙齿出现切断、挤压和研磨食物等状态,幽门系统内神经元的发放规律显示幽门节律出现依次发放的三个部分。两个神经系统的数值结果,不仅解释了龙虾胃肠神经系统中神经元电位发放与肌肉运动的关系,而且理论再现了龙虾胃肠神经系统的节律变化和实验结果。 展开更多
关键词 龙虾 胃研磨囊 幽门 神经元 电位 肌肉运动
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一种用于Marching-Graph图形绘制的快速收敛布局算法(英文) 被引量:3
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作者 全武 黄茂林 《软件学报》 EI CSCD 北大核心 2008年第8期1920-1932,共13页
Marching-Graph是一种将图形隐喻技术和空间隐喻技术集成为一体的新的可视化方法.它为用户提供了高度可交互性地图,使用户可访问那些具有地理属性的信息的逻辑结构.它通过有效的人图交互和跨空间浏览为用户提供了一种可视分析和挖掘未... Marching-Graph是一种将图形隐喻技术和空间隐喻技术集成为一体的新的可视化方法.它为用户提供了高度可交互性地图,使用户可访问那些具有地理属性的信息的逻辑结构.它通过有效的人图交互和跨空间浏览为用户提供了一种可视分析和挖掘未知信息的机制,而不是将已知的信息呈现在地图上.然而,传统的力导向布局算法在达到力量均衡配置方面非常慢.为使一个图形布局收敛,它们通常需花费几十秒的时间.因此。当用户快速行进于地理区间时,那些力导向布局算法就不能满足快速绘制一系列图形的要求.提出了一种快速收敛布局方法,当用户在Marching-Graph中通过力导向布局逐步探究一系列图形时,它可以加速交互时间.通过结合辐射树绘图技术和力导向图形绘制方法来取得能量最小化的快速收敛. 展开更多
关键词 图形和网络可视化 图形绘制 信息分析 信息可视化系统 可视设计
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The combined therapeutic effects of ^(131)iodinelabeled multifunctional copper sulfide-loaded microspheres in treating breast cancer 被引量:3
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作者 Qiufang Liu Yuyi Qian +10 位作者 Panli Li Sihang Zhang Zerong Wang Jianjun Liu Xiaoguang Sun Michael Fulham Dagan Feng Zhigang Chen Shaoli Song Wei Lu Gang Huang 《Acta Pharmaceutica Sinica B》 SCIE CAS CSCD 2018年第3期371-380,共10页
Compared to conventional cancer treatment, combination therapy based on well-designed nanoscale platforms may offer an opportunity to eliminate tumors and reduce recurrence and metastasis.In this study, we prepared mu... Compared to conventional cancer treatment, combination therapy based on well-designed nanoscale platforms may offer an opportunity to eliminate tumors and reduce recurrence and metastasis.In this study, we prepared multifunctional microspheres loading ^(131)I-labeled hollow copper sulfide nanoparticles and paclitaxel( ^(131)I-HCu SNPs-MS-PTX) for imaging and therapeutics of W256/B breast tumors in rats.18 F-fluordeoxyglucose(18 F-FDG) positron emission tomography/computed tomography(PET/CT) imaging detected that the expansion of the tumor volume was delayed(Po0.05) following intra-tumoral(i.t.) injection with ^(131)I-HCu SNPs-MS-PTX plus near-infrared(NIR) irradiation. The immunohistochemical analysis further confirmed the anti-tumor effect. The single photon emission computed tomography(SPECT)/photoacoustic imaging mediated by ^(131)I-HCu SNPs-MS-PTX demonstrated that microspheres were mainly distributed in the tumors with a relatively low distribution in other organs. Our results revealed that ^(131)I-HCu SNPs-MS-PTX offered combined photothermal, chemo-and radio-therapies, eliminating tumors at a relatively low dose, as well as allowing SPECT/CT and photoacoustic imaging monitoring of distribution of the injected agents non-invasively. The copper sulfide-loaded microspheres, ^(131)I-HCu SNPs-MS-PTX, can serve as a versatile theranostic agent in an orthotopic breast cancer model. 展开更多
关键词 MICROSPHERES THERANOSTICS Combination therapy Single photon emission computed tomography/computed tomography(SPECT/CT) Photoacoustic imaging
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Feature Representation in the Biclustering of Symptom-Herb Relationship in Chinese Medicine
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作者 Josiah Poon 罗哲 张润顺 《Chinese Journal of Integrative Medicine》 SCIE CAS 2011年第9期663-668,共6页
Objective:To find an appropriate feature representation in the biclustering of symptom-herb relationship in Chinese medicine(CM).Methods: Four different representation schemes were tested in identifying the comple... Objective:To find an appropriate feature representation in the biclustering of symptom-herb relationship in Chinese medicine(CM).Methods: Four different representation schemes were tested in identifying the complex relationship between symptoms and herbs using a biclustering algorithm on an insomnia data set.These representation schemes were effective count,binary value,relative success ratio,or modified relative success ratio.The comparison of the schemes was made on the number and size of biclusters with respect to different threshold values.Results and Conclusions:The modified relative success ratio scheme was the most appropriate feature representation among the four tested.Some of the biclusters selected from this representation scheme were known to follow the therapeutic principles of CM,while others may offer clues for further clinical investigations. 展开更多
关键词 feature representation BICLUSTERING Chinese medicine symptom-herb relationship
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Speaker adapted dynamic lexicons containing phonetic deviations of words
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作者 Bahram VAZIRNEZHAD Farshad ALMASGANJ +1 位作者 Seyed Mohammad AHADI Ari CHANEN 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2009年第10期1461-1475,共15页
Speaker variability is an important source of speech variations which makes continuous speech recognition a difficult task.Adapting automatic speech recognition(ASR) models to the speaker variations is a well-known st... Speaker variability is an important source of speech variations which makes continuous speech recognition a difficult task.Adapting automatic speech recognition(ASR) models to the speaker variations is a well-known strategy to cope with the challenge.Almost all such techniques focus on developing adaptation solutions within the acoustic models of the ASR systems.Although variations of the acoustic features constitute an important portion of the inter-speaker variations,they do not cover variations at the phonetic level.Phonetic variations are known to form an important part of variations which are influenced by both micro-segmental and suprasegmental factors.Inter-speaker phonetic variations are influenced by the structure and anatomy of a speaker's articulatory system and also his/her speaking style which is driven by many speaker background characteristics such as accent,gender,age,socioeconomic and educational class.The effect of inter-speaker variations in the feature space may cause explicit phone recognition errors.These errors can be compensated later by having appropriate pronunciation variants for the lexicon entries which consider likely phone misclassifications besides pronunciation.In this paper,we introduce speaker adaptive dynamic pronunciation models,which generate different lexicons for various speaker clusters and different ranges of speech rate.The models are hybrids of speaker adapted contextual rules and dynamic generalized decision trees,which take into account word phonological structures,rate of speech,unigram probabilities and stress to generate pronunciation variants of words.Employing the set of speaker adapted dynamic lexicons in a Farsi(Persian) continuous speech recognition task results in word error rate reductions of as much as 10.1% in a speaker-dependent scenario and 7.4% in a speaker-independent scenario. 展开更多
关键词 Pronunciation models Continuous speech recognition Lexicon adaptation
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