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基于Ghost-SE-Res2Net的多模型融合语音唤醒词检测方法 被引量:1
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作者 虞秋辰 周若华 袁庆升 《计算机工程》 CAS CSCD 北大核心 2024年第3期52-59,共8页
语音唤醒词检测(WWD)是语音交互中的关键技术,选择合适大小的检测窗对WWD性能的影响很大。提出一种新的多模型融合方法,通过融合小检测窗和大检测窗的检测结果来提高WWD性能。多模型融合方法包含两个分类模型,分别使用小检测窗和大检测... 语音唤醒词检测(WWD)是语音交互中的关键技术,选择合适大小的检测窗对WWD性能的影响很大。提出一种新的多模型融合方法,通过融合小检测窗和大检测窗的检测结果来提高WWD性能。多模型融合方法包含两个分类模型,分别使用小检测窗和大检测窗,均基于轻量化的挤压与激励残差网络(SE-Res2Net)模块,即GhostSE-Res2Net,SE-Res2Net结构的多尺度机制可显著提升WWD的能力。在Ghost-SE-Res2Net中,首先使用Ghost卷积替换SE-Res2Net中的普通卷积以降低模型参数量,然后使用注意力池化层替换SE-Res2Net中的全局平均池化层进一步提升WWD能力。在实际检测时融合连续3个小检测窗模型的检测结果的最大值和1个大检测窗模型的检测结果,来判断唤醒词是否被触发。在训练时引入困难样本挖掘算法,选择性地学习较难检测的唤醒词信息以提高分类模型的检测性能。在包含2个唤醒词的Mobvoi数据集上评估系统性能,实验结果表明,在每小时0.5次错误唤醒的情况下,该系统在2个唤醒词上的错误拒绝率分别为0.46%和0.43%,实现了与先进基线相似的性能,并且系统参数量比基线少31%。 展开更多
关键词 唤醒词检测 ghost模块 Res2Net结构 错误拒绝 多模型融合
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基于Ghost-YOLOv5s的SAR图像舰船目标检测
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作者 张慧敏 黄炜嘉 李锋 《火力与指挥控制》 CSCD 北大核心 2024年第4期24-30,共7页
基于星载合成孔径雷达(synthetic aperture radar,SAR)图像的舰船目标检测中,为了平衡模型大小与检测精度,提出了一种基于Ghost卷积的SAR图像舰船目标检测方法Ghost-YOLOv5s。在YOLOv5s的颈部引入Ghost卷积,以减少模型参数和压缩模型体... 基于星载合成孔径雷达(synthetic aperture radar,SAR)图像的舰船目标检测中,为了平衡模型大小与检测精度,提出了一种基于Ghost卷积的SAR图像舰船目标检测方法Ghost-YOLOv5s。在YOLOv5s的颈部引入Ghost卷积,以减少模型参数和压缩模型体积;将高效的通道注意力机制(efficient channel attention,ECA)融入到颈部的C3模块里,以突出重要特征,从而保持较高的检测性能;使用SIoU损失函数替换原来的CIoU损失函数,以减少预测框和真实框之间的偏差,提高检测算法精度。实验结果表明,在SSDD遥感数据集上,改进模型与YOLOv5s相比,模型参数量减少了6.28%,模型体积减小了6.21%,检测精度达到了98.21%,实现了模型大小与检测精度的平衡。 展开更多
关键词 合成孔径雷达 深度学习 ghost卷积 注意力机制
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基于Ghost模块的农资图像文本检测算法及其应用
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作者 殷昌山 杨林楠 罗爽 《湖北农业科学》 2024年第8期61-65,共5页
针对农资图像中文本的检测速度慢并且缺乏移动端的应用等问题,基于农资图像数据集,提出了一种基于Ghost模块的农资图像文本检测算法,该算法对DB网络进行改进,使用MobileNetv2网络来提取基础特征,引入多尺度特征融合模块来获得多层之间... 针对农资图像中文本的检测速度慢并且缺乏移动端的应用等问题,基于农资图像数据集,提出了一种基于Ghost模块的农资图像文本检测算法,该算法对DB网络进行改进,使用MobileNetv2网络来提取基础特征,引入多尺度特征融合模块来获得多层之间的特征融合,并采用可微分二值化后处理算法预测文本,使其能够快速地检测农资图像中的文本。该算法在农资图像数据集上的准确率基本达到了主流算法的标准,检测速度达18.6 img/s,参数量为2.99 M,具备轻量级的特征,将此算法部署到移动端设备上并成功运行。 展开更多
关键词 农资图像 文本检测 文本识别 ghost模块
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GHOSTS AND GORE A closer look at depiction of women in Thai horror movies
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作者 Tian Lin 《China Report ASEAN》 2023年第10期56-59,共4页
The 1999 Thai horror movie Nang Nak was the turning point for the“new wave”of Thai movies,and it became a model for the horror genre in Thailand.Even today,vengeance from female ghosts remains a central theme of Tha... The 1999 Thai horror movie Nang Nak was the turning point for the“new wave”of Thai movies,and it became a model for the horror genre in Thailand.Even today,vengeance from female ghosts remains a central theme of Thai horror movies. 展开更多
关键词 CLOSER ghost TURNING
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Joint Authentication Public Network Cryptographic Key Distribution Protocol Based on Single Exposure Compressive Ghost Imaging
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作者 俞文凯 王硕飞 商克谦 《Chinese Physics Letters》 SCIE EI CAS CSCD 2024年第2期47-56,共10页
In the existing ghost-imaging-based cryptographic key distribution(GCKD)protocols,the cryptographic keys need to be encoded by using many modulated patterns,which undoubtedly incurs long measurement time and huge memo... In the existing ghost-imaging-based cryptographic key distribution(GCKD)protocols,the cryptographic keys need to be encoded by using many modulated patterns,which undoubtedly incurs long measurement time and huge memory consumption.Given this,based on snapshot compressive ghost imaging,a public network cryptographic key distribution protocol is proposed,where the cryptographic keys and joint authentication information are encrypted into several color block diagrams to guarantee security.It transforms the previous single-pixel sequential multiple measurements into multi-pixel single exposure measurements,significantly reducing sampling time and memory storage.Both simulation and experimental results demonstrate the feasibility of this protocol and its ability to detect illegal attacks.Therefore,it takes GCKD a big step closer to practical applications. 展开更多
关键词 ghost ghost AUTHENTICATION
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High-visibility ghost imaging with phase-controlled discrete classical light sources
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作者 仵雪滢 赵岳 李利明 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第7期328-334,共7页
We take phase modulation to create discrete phase-controlled sources and realize the super-bunching effect by a phasecorrelated method. From theoretical and numerical simulations, we find the space translation invaria... We take phase modulation to create discrete phase-controlled sources and realize the super-bunching effect by a phasecorrelated method. From theoretical and numerical simulations, we find the space translation invariance of the bunching effect is a key point for the ghost imaging realization. Experimentally, we create the orderly phase-correlated discrete sources which can realize high-visibility second-order ghost imaging than the result with chaotic sources. Moreover, some factors affecting the visibility of ghost image are discussed in detail. 展开更多
关键词 ghost imaging high visibility space translation invariance
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基于Ghost卷积的高级别浆液性卵巢癌复发预测方法
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作者 唐艺菠 崔少国 +2 位作者 万皓明 王锐 刘丽丽 《计算机与现代化》 2024年第4期43-47,98,共6页
高级别浆液性卵巢癌是一种恶性肿瘤疾病,进行术前复发预测能帮助临床医生为患者提供个性化治疗方案,降低病人的死亡率。因该疾病的医学数据较少且难以获取,导致其深度学习模型难以得到充分的训练,复发预测准确率有待提高。针对此问题,... 高级别浆液性卵巢癌是一种恶性肿瘤疾病,进行术前复发预测能帮助临床医生为患者提供个性化治疗方案,降低病人的死亡率。因该疾病的医学数据较少且难以获取,导致其深度学习模型难以得到充分的训练,复发预测准确率有待提高。针对此问题,本文设计了一种改进的低参数残差网络TGE-ResNet34,以ResNet34为主干网络,将传统卷积模块用Ghost卷积代替,完成病灶区特征的提取,降低模型的参数量,在2个Ghost卷积之间融入ECA(Efficient Channel Attention)注意力机制,抑制无用特征提取的干扰,最后通过5折交叉验证模型,避免数据随机划分的偶然性。实验结果表明,改进设计的TGE-ResNet34网络准确率为96.01%,相比原基线网络准确率提高4.52个百分点,参数量减少15.98 M。 展开更多
关键词 高级别浆液性卵巢癌 残差网络 ghost卷积 注意力
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Petrographic and Geochemical Characteristics of the Granitoids in the South of Godé (North of the Square Degree of Léo-Burkina Faso, West Africa)
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作者 Adama Ouédraogo Yaméogo Hubert Gounwendmanaghré Zongo +4 位作者 Pascal Ouiya Omar Akonyiré Abraham Seydoux Traoré Saga Sawadogo Séta Naba 《International Journal of Geosciences》 CAS 2024年第2期106-118,共13页
South of Godé, in the central-western region of Burkina Faso, granitoids of Paleoproterozoic age are similar to those of the Man/Leo shield. This study focused on the petrographic and geochemical characteristics ... South of Godé, in the central-western region of Burkina Faso, granitoids of Paleoproterozoic age are similar to those of the Man/Leo shield. This study focused on the petrographic and geochemical characteristics of these granitoids, with the following results: 1) The tonalite that outcrops in the south-west of the study area belongs to the TTG group or first generation granitoids. They are most often ribboned at outcrop and have a geochemical signature close to that of Archean TTGs. Tonalite has a metaluminous character and the REE spectrum indicates that it may be derived from partial melting of basic magmatic rocks. 2) Biotite granites have no outcrop structure. They are weakly metaluminous to peraluminous and potassic to highly potassic. Their rare earth spectra indicate that they may be derived from the partial melting of TTG granitoids. 3) Geotectonic diagrams show that the granitoids studied to the south of Godé were emplaced in an active tectonic context similar to that of present-day subduction zones. 展开更多
关键词 Burkina Faso godé Man/Leo Shield PETROGRAPHY Geochemistry Partial Melting Geotectonic Setting
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项目的PPP模式适用性GOD分析——以智慧城市建设项目为例 被引量:1
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作者 叶苏东 杨家琴 《北京交通大学学报(社会科学版)》 北大核心 2023年第2期117-124,共8页
政府和社会资本合作模式的应用越来越广。然而,并不是所有的项目都适合采用PPP模式,出现了PPP模式的滥用。为了判断项目的 PPP模式适用性,本文提出GOD(Goods-Operation-Delivery)分析方法,把PPP模式适用性问题简化为三个步骤及三项判断... 政府和社会资本合作模式的应用越来越广。然而,并不是所有的项目都适合采用PPP模式,出现了PPP模式的滥用。为了判断项目的 PPP模式适用性,本文提出GOD(Goods-Operation-Delivery)分析方法,把PPP模式适用性问题简化为三个步骤及三项判断准则:首先,以公共产品理论为基础,根据项目产出的属性识别出无需采用PPP模式的项目;其次,以公共权力理论为基础,根据项目运行的属性识别出不能采用PPP模式的项目;最后,基于比较优势理念,根据项目交付模式的效率确定是否优先采用PPP模式。为了演示GOD分析的应用,本文对智慧城市建设项目的 PPP模式适用性进行了演示性分析,结果表明GOD分析可以较好地分析项目的 PPP适用性。 展开更多
关键词 PPP模式 适用性 god分析 智慧城市
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基于Ghost模块的改进YOLOv5目标检测算法 被引量:4
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作者 李宇翔 王帅 +2 位作者 陈伟 田子建 侯麟朔 《现代电子技术》 2023年第3期29-34,共6页
现有以YOLOv5为代表的目标检测技术,存在骨干网络对特征提取不充分以及颈部层未高效融合浅层位置信息和深层高级语义信息等问题,这会导致检测精度较低,小目标误检、漏检。针对此问题,从兼顾实时性与检测精度出发,对YOLOv5进行改进,提出... 现有以YOLOv5为代表的目标检测技术,存在骨干网络对特征提取不充分以及颈部层未高效融合浅层位置信息和深层高级语义信息等问题,这会导致检测精度较低,小目标误检、漏检。针对此问题,从兼顾实时性与检测精度出发,对YOLOv5进行改进,提出一种改进网络YOLOv5-CBGhost。首先在骨干网络中引入Ghost模块对模型进行轻量化处理,引入CA模块来更好地获得全局感受野,提高模型获取目标位置的准确度;然后借鉴双向加权特征金字塔网络,对原PAN结构进行改进,有效减少了特征冗余以及参数量,并通过跨层加权连接融合更多特征,提高了模型的目标检测精度;最后,增加多检测头以获取图片更丰富的高层语义信息,有效增加了检测精度。通过在PASCAL VOC2007+2012数据集上实验,YOLOv5-CBGhost的目标精度达到81.8%,相较于YOLOv5s,提高了3.0%,计算量减少42.5%,模型大小减少3.5%。 展开更多
关键词 目标检测 YOLOv5改进 ghost模块 模型处理 PAN结构改进 特征融合
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On the Stringy Ghosts Which We Call the Missing Dark Energy of the Cosmos 被引量:1
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作者 Mohamed S. El Naschie 《Journal of Applied Mathematics and Physics》 2016年第6期979-987,共9页
Dark energy is explained using familiar notions and concepts used in quantum field theory, string theory and the exact mathematical theory of spacetime. The main result of the present work is first a new mathematical ... Dark energy is explained using familiar notions and concepts used in quantum field theory, string theory and the exact mathematical theory of spacetime. The main result of the present work is first a new mathematical definition of pre-quantum spacetime (QST) as a multiset made of infinitely many empty Cantor sets connected to pre-quantum wave empty set (QW) and the pre-quantum particle (QP) zero set via the cobordism equation &#8706(QW) = (QP)U(QST). Second, and in turn, this new path of reasoning is used to validate the quantum splitting of Einstein’s E = mc<sup>2</sup> into the sum of the ordinary energy E = mc<sup>2</sup>/22 of the quantum particle and the dark energy E = mc<sup>2</sup>(21/22) of the quantum wave, used predominantly to explain the observed accelerated expansion of the universe. 展开更多
关键词 Quantum Spacetime Quantum ghost States Dark Energy Spacetime Cobordism E-Infinity Theory Fractal-Cantorian Spacetime Noncommutative Geometry ‘t Hooft-Susskind Holography
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融合注意力机制与GhostUNet的路面裂缝检测方法
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作者 赵志宏 郝子晔 何朋 《电子测量技术》 北大核心 2023年第24期164-171,共8页
路面裂缝是道路最为常见的缺陷,随着深度学习技术的发展,利用深度学习的方法对路面图像中的裂缝信息提取的方法愈来愈多。针对现有深度学习路面裂缝检测方法提取裂缝特征不完整导致精度低以及实时性不足的问题,提出一种融合注意力机制与... 路面裂缝是道路最为常见的缺陷,随着深度学习技术的发展,利用深度学习的方法对路面图像中的裂缝信息提取的方法愈来愈多。针对现有深度学习路面裂缝检测方法提取裂缝特征不完整导致精度低以及实时性不足的问题,提出一种融合注意力机制与GhostUNet的路面裂缝检测方法。本方法由编码器和解码器组成,将U-Net中的常规卷积改进为Ghost卷积,减少模型参数量;在编码和解码部分,为了提高对裂缝特征的提取能力,引入ECA注意力机制和残差连接,ECA注意力模块可以过滤不相关的特征信息,利用残差连接可以避免网络退化现象。为评估本方法在裂缝检测方面的有效性,使用两个公开裂缝数据集,并进行消融实验和对比实验,实验结果F1_score、P和R分别比U-Net平均提高了14.48%、14.35%和14.45%;该模型相比U-Net参数量下降了14.2 MB。该模型与同类模型比较,分割的准确率更高,参数量更少。 展开更多
关键词 裂缝检测 ghost U-Net ECA 残差连接
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Optimization method of Hadamard coding plate inγ‑ray computational ghost imaging 被引量:3
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作者 Zhi Zhou San‑Gang Li +5 位作者 Qing‑Shan Tan Li Yang Ming‑Zhe Liu Ming Wang Lei Wang Yi Cheng 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第1期146-156,共11页
Owing to the constraints on the fabrication ofγ-ray coding plates with many pixels,few studies have been carried out onγ-ray computational ghost imaging.Thus,the development of coding plates with fewer pixels is ess... Owing to the constraints on the fabrication ofγ-ray coding plates with many pixels,few studies have been carried out onγ-ray computational ghost imaging.Thus,the development of coding plates with fewer pixels is essential to achieveγ-ray computational ghost imaging.Based on the regional similarity between Hadamard subcoding plates,this study presents an optimization method to reduce the number of pixels of Hadamard coding plates.First,a moving distance matrix was obtained to describe the regional similarity quantitatively.Second,based on the matrix,we used two ant colony optimization arrangement algorithms to maximize the reuse of pixels in the regional similarity area and obtain new compressed coding plates.With full sampling,these two algorithms improved the pixel utilization of the coding plate,and the compression ratio values were 54.2%and 58.9%,respectively.In addition,three undersampled sequences(the Harr,Russian dolls,and cake-cutting sequences)with different sampling rates were tested and discussed.With different sampling rates,our method reduced the number of pixels of all three sequences,especially for the Russian dolls and cake-cutting sequences.Therefore,our method can reduce the number of pixels,manufacturing cost,and difficulty of the coding plate,which is beneficial for the implementation and application ofγ-ray computational ghost imaging. 展开更多
关键词 γ-ray computational ghost imaging Regional similarity Hadamard coding plate
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Study on Genetic Inactivation Bacterial Ghosts of Pasteurella multocida based PhiX174 Gene E Lysis Cassette Mediated
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作者 ZHU Bi-feng YANG Xu-fu LIU Dong-sheng 《Animal Husbandry and Feed Science》 CAS 2012年第4期172-175,共4页
[Objective] To study on genetic inactivation bacterial ghosts of Pasteurella multocida based PhiX174 gene E lysis cassette mediated. [ Method ] Recombinant pPBA1100-e was constructed by which the gene E of bacteriopha... [Objective] To study on genetic inactivation bacterial ghosts of Pasteurella multocida based PhiX174 gene E lysis cassette mediated. [ Method ] Recombinant pPBA1100-e was constructed by which the gene E of bacteriophage Phix174 and temperature sensitivity expressing control system hybridized with plasmid pPBA1100 by genetic engineering method. Recombinant was transformed to Pasteurella multocida and lysis gene E expressed by temperature induction. Recombinant was detected by restriction endonuclease. Cell morphology of bacterial ghost of Pasteurella mul- tocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysis. I Result~ The results indicated that the recombination plasmid presented three bands by restriction endonuclease and agarose electrophoresis and that molecular weight of every band ac- corded with theoretical value. The result of SEM observing showed that recombination plasmid expressed successfully in P. multocida and produced bacterial ghost. The result of CFU detecting demonstrated that inactivation ratio of P. multocida reached 99 per cent. ~Conclusion~ This study pro- vided technical bases for the preparation of antigen vaccine of natural bacterial outer membrane protein. 展开更多
关键词 lysis gene E P. multocida Bacterial ghost Plasmid construction
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Ghost-Retina Net:Fast Shadow Detection Method for Photovoltaic Panels Based on Improved Retina Net 被引量:1
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作者 Jun Wu Penghui Fan +1 位作者 Yingxin Sun Weifeng Gui 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第2期1305-1321,共17页
Based on the artificial intelligence algorithm of RetinaNet,we propose the Ghost-RetinaNet in this paper,a fast shadow detection method for photovoltaic panels,to solve the problems of extreme target density,large ove... Based on the artificial intelligence algorithm of RetinaNet,we propose the Ghost-RetinaNet in this paper,a fast shadow detection method for photovoltaic panels,to solve the problems of extreme target density,large overlap,high cost and poor real-time performance in photovoltaic panel shadow detection.Firstly,the Ghost CSP module based on Cross Stage Partial(CSP)is adopted in feature extraction network to improve the accuracy and detection speed.Based on extracted features,recursive feature fusion structure ismentioned to enhance the feature information of all objects.We introduce the SiLU activation function and CIoU Loss to increase the learning and generalization ability of the network and improve the positioning accuracy of the bounding box regression,respectively.Finally,in order to achieve fast detection,the Ghost strategy is chosen to lighten the size of the algorithm.The results of the experiment show that the average detection accuracy(mAP)of the algorithm can reach up to 97.17%,the model size is only 8.75 MB and the detection speed is highly up to 50.8 Frame per second(FPS),which can meet the requirements of real-time detection speed and accuracy of photovoltaic panels in the practical environment.The realization of the algorithm also provides new research methods and ideas for fault detection in the photovoltaic power generation system. 展开更多
关键词 Deep learning intensive object detection photovoltaic panel shadow ghost module retinanet
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To Appreciate and Comprehend the Ghosts Elements in A Christmas Carol
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作者 张静 《科技信息》 2010年第10期I0154-I0155,共2页
This paper explores the message hidden in the ghost characters in Dickens'A Christmas Carol. There are an immense number of books about ghost both in Chinese and British literature. Ghost is an imaginary afterlife... This paper explores the message hidden in the ghost characters in Dickens'A Christmas Carol. There are an immense number of books about ghost both in Chinese and British literature. Ghost is an imaginary afterlife of human being; similarly novel is also a kind of fiction based on the real life. Therefore,when novels are used to shape the ghost images,there will be a powerful and unstrained space produced by the double-tier imagination. The ghost novels can also serve as a mirror of human society and speak of some problems in human life. So a better understanding of the ghost characters in literature can give us a deep insight into the society at the time when the story took place,as well as providing us a good chance of literature appreciation.Considering the role that the ghosts play in this novel,it should be called memory figures,developing Scrooge from a character wishing to shut out his past to one living in the past,the present,and the future. The first indication of his character can be derived from the remark that he takes "his melancholy dinner in his usual melancholy tavern" and then returns to his "gloomy suite of rooms ". The adjectives tell us that Scrooge should have a talent for remem?brance or rather a good memory. His humoral constitution predisposes him for it. The three ghosts,whose visitation Marley announced,each take Scrooge to places,to towns and buildings,the most traditional type of image in artificial memory. It is typical of these visits that Scrooge,like Vergil in Dante's Divine Comedy,becomes an invisible visitor,who enters the world of his past evoked by the memorial places. This immediate contact appears as a precondition for the reformative influence of the past on Scrooge. If we look back to an earlier Christmas story,which also preaches the change of heart,Dickens' new and specific frame of reference shows up even more clearly. (Cerny,257) 展开更多
关键词 外语教学 教学方法 研究 方法
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GOLD AND SILVER WINGED GODS FROM THE TUBO PERIOD 被引量:1
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作者 Huo Wei 《China's Tibet》 2018年第1期54-57,共4页
Ethnic people living on the Tibetan Plateau during the Tubo period have been well-known as not only strong and brave on horses,but they were also an ethnic group enriched with powerful creativity and rich imagination.... Ethnic people living on the Tibetan Plateau during the Tubo period have been well-known as not only strong and brave on horses,but they were also an ethnic group enriched with powerful creativity and rich imagination.From Tubo’s cultural art,we can observe a large amount of extremely fine artifacts.For instance,among 展开更多
关键词 GOLD AND SILVER WINGED gods FROM THE TUBO PERIOD
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Ghosts in the shell:identification of microglia in the human central nervous system by P2Y12 receptor
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作者 alexander mildner 《Neural Regeneration Research》 SCIE CAS CSCD 2017年第4期570-571,共2页
Microglia are the tissue resident macrophages of the brain and represent the sole immune population located in the parenchyma of the central nervous system (CNS). These cells are hidden be-tween neurons, astrocytes ... Microglia are the tissue resident macrophages of the brain and represent the sole immune population located in the parenchyma of the central nervous system (CNS). These cells are hidden be-tween neurons, astrocytes as well as oligodendrocytes and account for only 5-10% of CNS cells. Even though microglia were already identified in 1913 by the Spanish neuroanatomist Ramon y Cajal and further seminally investigated by his student Pio del Rio Hortega, 展开更多
关键词 ghosts in the shell identification of microglia in the human central nervous system by P2Y12 receptor
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Optical encryption scheme based on spread spectrum ghost imaging
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作者 刘进芬 董玥 +1 位作者 王乐 赵生妹 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第7期375-381,共7页
An optical encryption(OE) scheme based on the spread spectrum ghost imaging(SSGI), named as SSGI-OE, is proposed to obtain a high security with a smaller key. In the scheme, the randomly selected row number of a Hadam... An optical encryption(OE) scheme based on the spread spectrum ghost imaging(SSGI), named as SSGI-OE, is proposed to obtain a high security with a smaller key. In the scheme, the randomly selected row number of a Hadamard matrix of order N is used as the secure key, and shared with the authorized user, Bob, through a private channel. Each corresponding row vector of the order-N Hadamard matrix is then used as the direct sequence code to modulate a speckle pattern for the ghost imaging system, and an image is encrypted with the help of the SSGI. The measurement results from the bucket detector, named as ciphertext, are then transmitted to Bob through a public channel. The illuminating speckle patterns are also shared with Bob by the public channel. With the correct secure key, Bob could reconstruct the image with the aid of the SSGI system, whereas the unauthorized user, Eve, could not obtain any useful information of the encrypted image. The numerical simulations and experimental results show that the proposed scheme is feasible with a higher security and a smaller key. For the 32 × 32 pixels image, the number of bits sent from Alice to Bob by using SSGIOE(M = 1024, N = 2048) scheme is only 0.0107 times over a computational ghost imaging optical encryption scheme.When the eavesdropping ratio(ER) is less than 40%, the eavesdropper cannot acquire any information of the encrypted image. The extreme circumstance for the proposed SSGI-OE scheme is also discussed, where the eavesdropper begins to extract the information when ER is up to 15%. 展开更多
关键词 optical encryption ghost imaging spread spectrum correlated imaging
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Principle of subtraction ghost imaging in scattering medium
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作者 付芹 白艳锋 +3 位作者 谭威 黄贤伟 南苏琴 傅喜泉 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第6期250-254,共5页
Scattering medium in light path will cause distortion of the light field,resulting in poor signal-to-noise ratio(SNR)of ghost imaging.The disturbance is usually eliminated by the method of pre-compensation.We deduce t... Scattering medium in light path will cause distortion of the light field,resulting in poor signal-to-noise ratio(SNR)of ghost imaging.The disturbance is usually eliminated by the method of pre-compensation.We deduce the intensity fluctuation correlation function of the ghost imaging with the disturbance of the scattering medium,which proves that the ghost image consists of two correlated results:the image of scattering medium and the target object.The effect of the scattering medium can be eliminated by subtracting the correlated result between the light field after the scattering medium and the reference light from ghost image,which verifies the theoretical results.Our research may provide a new idea of ghost imaging in harsh environment. 展开更多
关键词 ghost imaging image reconstruction techniques scattering medium
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