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Has Okun's Law Become Invalid in China?——Estimation of Potential GDP Growth Rates and Natural Rates of Unemployment Based on Dual Structure
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作者 邹沛江 《China Economist》 2014年第1期53-67,共15页
This paper calculates the potential GDP growth rates and the natural rates of unemployment in China using the dual decomposition of the simple Ohm's law.The results show that every 1%increase in China's urban ... This paper calculates the potential GDP growth rates and the natural rates of unemployment in China using the dual decomposition of the simple Ohm's law.The results show that every 1%increase in China's urban registered unemployment rate leads to a 1.98%drop of GDP,the potential growth rate of GDP of China is about 10%,and the average natural rate of unemployment is about 3.2%in China in the past three decades.The paper finds that Okun's law is still valid in China in the long run,but the Okun coefficient is about-3.79,overestimating the impact of the registered unemployment rate on GDP growth,and needs to be corrected based on China's dual economic structure. 展开更多
关键词 GDP增长率 失业率 中国 定律 自然 二元结构 国内生产总值 失效
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基于多尺度Laws纹理能量和低秩分解的织物疵点检测算法
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作者 王振华 张周强 +1 位作者 昝杰 刘江浩 《纺织学报》 EI CAS CSCD 北大核心 2024年第4期96-104,共9页
为提高织物疵点检测算法对简单纹理织物、模式纹理织物及条纹纹理织物检测时的普适性和准确性,提出了一种基于多尺度Laws纹理能量和低秩分解的织物疵点检测算法。首先,对织物图像进行直方图均衡化并将处理后的图像均匀划分为子图像块;其... 为提高织物疵点检测算法对简单纹理织物、模式纹理织物及条纹纹理织物检测时的普适性和准确性,提出了一种基于多尺度Laws纹理能量和低秩分解的织物疵点检测算法。首先,对织物图像进行直方图均衡化并将处理后的图像均匀划分为子图像块;其次,对每个子图像块提取28个纹理能量特征(利用7个Laws滤波模板在4个尺度上提取),计算所有子图像块提取到的特征均值并组成特征矩阵;然后,利用特征矩阵构建低秩分解模型,通过方向交替方法(ADM)优化求解,得到低秩部分和稀疏部分;最后,由稀疏部分生成疵点显著图,采用迭代阈值分割法对其进行分割,得到织物疵点检测结果。为验证该算法的有效性,在织物图像数据集选取了包含错纬、断经、跳花、破洞等常见疵点的织物图像,并将实验结果与已有3种算法进行了对比。实验结果表明,该算法在简单纹理织物、模式纹理织物及条纹纹理织物检测上具有更好的普适性和准确性,且检测效率具有一定优势。 展开更多
关键词 织物疵点 疵点检测 laws纹理 纹理能量 特征提取 矩阵低秩分解
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Nonuniform Dependence on the Initial Data for Solutions of Conservation Laws
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作者 John M.Holmes Barbara Lee Keyfitz 《Communications on Applied Mathematics and Computation》 EI 2024年第1期489-500,共12页
In this paper,we study systems of conservation laws in one space dimension.We prove that for classical solutions in Sobolev spaces H^(s),with s>3/2,the data-to-solution map is not uniformly continuous.Our results a... In this paper,we study systems of conservation laws in one space dimension.We prove that for classical solutions in Sobolev spaces H^(s),with s>3/2,the data-to-solution map is not uniformly continuous.Our results apply to all nonlinear scalar conservation laws and to nonlinear hyperbolic systems of two equations. 展开更多
关键词 Conservation laws Data-to-solution map Nonuniform dependence
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Triple reverse order law for the Drazin inverse
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作者 WANG Hua ZHONG Cheng-cheng 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2024年第1期55-68,共14页
In this paper,we investigate the reverse order law for Drazin inverse of three bound-ed linear operators under some commutation relations.Moreover,the Drazin invertibility of sum is also obtained for two bounded linea... In this paper,we investigate the reverse order law for Drazin inverse of three bound-ed linear operators under some commutation relations.Moreover,the Drazin invertibility of sum is also obtained for two bounded linear operators and its expression is presented. 展开更多
关键词 Drazin inverse reverse order law space decomposition
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Literature overview of basic characteristics and flotation laws of flocs
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作者 Wanzhong Yin Yu Xie Zhanglei Zhu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第5期943-958,共16页
Flocculation flotation is the most efficient method for recovering fine-grained minerals,and its essence lies in flotation and recovery of flocs.Fundamental physical characteristics of flocs are mainly determined by t... Flocculation flotation is the most efficient method for recovering fine-grained minerals,and its essence lies in flotation and recovery of flocs.Fundamental physical characteristics of flocs are mainly determined by their apparent particle size and structure(density and morphology).Substantial researches have been conducted regarding the effect of floc characteristics on particle settling and water treatment.However,the influence of floc characteristics on flotation has not been widely studied.Based on the floc formation and flocculation flotation,this study reviews the fundamental physical characteristics of flocs from the perspectives of floc particle size and structure,summarizing the interaction between floc particle size and structure.Moreover,it thoroughly discusses the effect of floc particle size and structure on floc floatability,further revealing the influence of floc characteristics on bubble collision and adhesion and elucidating the mechanisms of interaction between flocs and bubbles.Thus,it is observed that floc particle size is not the only factor influencing flocculation flotation.Within the appropriate apparent particle size range,flocs with a compact structure exhibit higher efficiency in bubble collision and adhesion during flotation,thereby resulting in enhanced flotation performance.This study aims to provide a reference for flocculation flotation,targeting the development of more efficient and refined flocculation flotation processes in the future. 展开更多
关键词 FLOCS basic characteristics particle size and structure flotation laws BUBBLES
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Dimension by Dimension Finite Volume HWENO Method for Hyperbolic Conservation Laws
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作者 Feng Zheng Jianxian Qiu 《Communications on Applied Mathematics and Computation》 EI 2024年第1期605-624,共20页
In this paper,we propose a finite volume Hermite weighted essentially non-oscillatory(HWENO)method based on the dimension by dimension framework to solve hyperbolic conservation laws.It can maintain the high accuracy ... In this paper,we propose a finite volume Hermite weighted essentially non-oscillatory(HWENO)method based on the dimension by dimension framework to solve hyperbolic conservation laws.It can maintain the high accuracy in the smooth region and obtain the high resolution solution when the discontinuity appears,and it is compact which will be good for giving the numerical boundary conditions.Furthermore,it avoids complicated least square procedure when we implement the genuine two dimensional(2D)finite volume HWENO reconstruction,and it can be regarded as a generalization of the one dimensional(1D)HWENO method.Extensive numerical tests are performed to verify the high resolution and high accuracy of the scheme. 展开更多
关键词 Finite volume Dimension by dimension HWENO Hyperbolic conservation laws
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Distribution law and susceptibility of geohazards across a gradient belt of the Western Sichuan Plateau
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作者 LI Tianbin WANG Jianfeng +4 位作者 HE Chaoyang MENG Lubo LI Chaofei MA Junjie WEI Daqiang 《Journal of Mountain Science》 SCIE CSCD 2024年第6期1849-1867,共19页
Across a gradient belt of the Western Sichuan Plateau,geohazards have seriously limited economic and social development.According to incomplete statistics,15,673 geohazards have been recorded in the study area.In orde... Across a gradient belt of the Western Sichuan Plateau,geohazards have seriously limited economic and social development.According to incomplete statistics,15,673 geohazards have been recorded in the study area.In order to mitigate the threat of geohazards to human engineering activities in the region,an overall understanding of the distribution pattern of geohazards and susceptibility assessment are necessary.In this paper,a gradient belt of the Western Sichuan Plateau and its zoning criteria were defined.Subsequently,on the basis of relief amplitude,distance to faults,rainfall,and human activities,three indicators of endogenic process were introduced:Bouguer gravity anomaly gradient,vertical deformation gradient,and horizontal deformation gradient.Thereafter,the distribution patterns of geohazards were investigated through mathematical statistics and ArcGIS software.By randomly selecting 10,449 hazards,a geohazard susceptibility map was generated using the Information Value(IV)model.Finally,the IV model was validated against 5224 hazards using the Area Under Curve(AUC)method.The results show that 47.6%of the geohazards were distributed in the zone of steep slope.Geohazards showed strong responses to distance to faults,human activities,and annual rainfall.The distribution of geohazards in the gradient belt of the Western Sichuan Plateau is more sensitive to vertical internal dynamics factors(such as vertical deformation gradient and Bouguer gravity anomaly gradient)without any apparent sensitivity to horizontal internal dynamics factors.The areas of high and very-high risk account for up to 32.22%,mainly distributed in the Longmenshan and Anning River faults.According to the AUC plot,the success rate of the IV model for generating the susceptibility map is 76%.This susceptibility map and geohazard distribution pattern can provide a reference for geological disaster monitoring,preparation of post-disaster emergency measures,and town planning. 展开更多
关键词 Gradient belt GEOHAZARDS Distribution law Bouguer Gravity anomaly gradient Vertical deformation gradient SUSCEPTIBILITY
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Nuclear magnetic resonance experiments on the time-varying law of oil viscosity and wettability in high-multiple waterflooding sandstone cores
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作者 JIA Hu ZHANG Rui +2 位作者 LUO Xianbo ZHOU Zili YANG Lu 《Petroleum Exploration and Development》 SCIE 2024年第2期394-402,共9页
A simulated oil viscosity prediction model is established according to the relationship between simulated oil viscosity and geometric mean value of T2spectrum,and the time-varying law of simulated oil viscosity in por... A simulated oil viscosity prediction model is established according to the relationship between simulated oil viscosity and geometric mean value of T2spectrum,and the time-varying law of simulated oil viscosity in porous media is quantitatively characterized by nuclear magnetic resonance(NMR)experiments of high multiple waterflooding.A new NMR wettability index formula is derived based on NMR relaxation theory to quantitatively characterize the time-varying law of rock wettability during waterflooding combined with high-multiple waterflooding experiment in sandstone cores.The remaining oil viscosity in the core is positively correlated with the displacing water multiple.The remaining oil viscosity increases rapidly when the displacing water multiple is low,and increases slowly when the displacing water multiple is high.The variation of remaining oil viscosity is related to the reservoir heterogeneity.The stronger the reservoir homogeneity,the higher the content of heavy components in the remaining oil and the higher the viscosity.The reservoir wettability changes after water injection:the oil-wet reservoir changes into water-wet reservoir,while the water-wet reservoir becomes more hydrophilic;the degree of change enhances with the increase of displacing water multiple.There is a high correlation between the time-varying oil viscosity and the time-varying wettability,and the change of oil viscosity cannot be ignored.The NMR wettability index calculated by considering the change of oil viscosity is more consistent with the tested Amott(spontaneous imbibition)wettability index,which agrees more with the time-varying law of reservoir wettability. 展开更多
关键词 SANDSTONE high-multiple waterflooding nuclear magnetic resonance oil viscosity rock wettability time-varying law
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Weber Law Based Approach for Multi-Class Image Forgery Detection
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作者 Arslan Akram Javed Rashid +3 位作者 Arfan Jaffar Fahima Hajjej Waseem Iqbal Nadeem Sarwar 《Computers, Materials & Continua》 SCIE EI 2024年第1期145-166,共22页
Today’s forensic science introduces a new research area for digital image analysis formultimedia security.So,Image authentication issues have been raised due to the wide use of image manipulation software to obtain a... Today’s forensic science introduces a new research area for digital image analysis formultimedia security.So,Image authentication issues have been raised due to the wide use of image manipulation software to obtain an illegitimate benefit or createmisleading publicity by using tempered images.Exiting forgery detectionmethods can classify only one of the most widely used Copy-Move and splicing forgeries.However,an image can contain one or more types of forgeries.This study has proposed a hybridmethod for classifying Copy-Move and splicing images using texture information of images in the spatial domain.Firstly,images are divided into equal blocks to get scale-invariant features.Weber law has been used for getting texture features,and finally,XGBOOST is used to classify both Copy-Move and splicing forgery.The proposed method classified three types of forgeries,i.e.,splicing,Copy-Move,and healthy.Benchmarked(CASIA 2.0,MICCF200)and RCMFD datasets are used for training and testing.On average,the proposed method achieved 97.3% accuracy on benchmarked datasets and 98.3% on RCMFD datasets by applying 10-fold cross-validation,which is far better than existing methods. 展开更多
关键词 Copy-Move and splicing non-overlapping block division texture features weber law spatial domain xgboost
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Development and Application of a Power Law Constitutive Model for Eddy Current Dampers
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作者 Longteng Liang Zhouquan Feng +2 位作者 Hongyi Zhang Zhengqing Chen Changzhao Qian 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第3期2403-2419,共17页
Eddy current dampers (ECDs) have emerged as highly desirable solutions for vibration control due to theirexceptional damping performance and durability. However, the existing constitutive models present challenges tot... Eddy current dampers (ECDs) have emerged as highly desirable solutions for vibration control due to theirexceptional damping performance and durability. However, the existing constitutive models present challenges tothe widespread implementation of ECD technology, and there is limited availability of finite element analysis (FEA)software capable of accurately modeling the behavior of ECDs. This study addresses these issues by developing anewconstitutivemodel that is both easily understandable and user-friendly for FEAsoftware. By utilizing numericalresults obtained from electromagnetic FEA, a novel power law constitutive model is proposed to capture thenonlinear behavior of ECDs. The effectiveness of the power law constitutive model is validated throughmechanicalproperty tests and numerical seismic analysis. Furthermore, a detailed description of the application process ofthe power law constitutive model in ANSYS FEA software is provided. To facilitate the preliminary design ofECDs, an analytical derivation of energy dissipation and parameter optimization for ECDs under harmonicmotionis performed. The results demonstrate that the power law constitutive model serves as a viable alternative forconducting dynamic analysis using FEA and optimizing parameters for ECDs. 展开更多
关键词 Eddy current damper constitutive model finite element analysis vibration control power law constitutive model
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The Rule of Law is the Most Important Means of Human Rights Protection
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作者 马怀德 CHEN Feng 《The Journal of Human Rights》 2024年第1期80-82,共3页
Today,we are here to commemorate the 75^(th) anniversary of the adoption of the Universal Declaration of Human Rights.In this Declaration,which consists of only30 articles,seven articles are related to the constitutio... Today,we are here to commemorate the 75^(th) anniversary of the adoption of the Universal Declaration of Human Rights.In this Declaration,which consists of only30 articles,seven articles are related to the constitution,law,court,and the rule of law,making it a declaration filled with the rule of law.Coincidentally,today is also the 10^(th) National Constitution Day of China.Nineteen years ago,“the state respects and protects human rights”was enshrined in the Constitution,becoming a constitutional principle.Since then,human rights protection in China has been based on fundamental law. 展开更多
关键词 ANNIVERSARY law HUMAN
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A Spectral Convolutional Neural Network Model Based on Adaptive Fick’s Law for Hyperspectral Image Classification
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作者 Tsu-Yang Wu Haonan Li +1 位作者 Saru Kumari Chien-Ming Chen 《Computers, Materials & Continua》 SCIE EI 2024年第4期19-46,共28页
Hyperspectral image classification stands as a pivotal task within the field of remote sensing,yet achieving highprecision classification remains a significant challenge.In response to this challenge,a Spectral Convol... Hyperspectral image classification stands as a pivotal task within the field of remote sensing,yet achieving highprecision classification remains a significant challenge.In response to this challenge,a Spectral Convolutional Neural Network model based on Adaptive Fick’s Law Algorithm(AFLA-SCNN)is proposed.The Adaptive Fick’s Law Algorithm(AFLA)constitutes a novel metaheuristic algorithm introduced herein,encompassing three new strategies:Adaptive weight factor,Gaussian mutation,and probability update policy.With adaptive weight factor,the algorithmcan adjust theweights according to the change in the number of iterations to improve the performance of the algorithm.Gaussianmutation helps the algorithm avoid falling into local optimal solutions and improves the searchability of the algorithm.The probability update strategy helps to improve the exploitability and adaptability of the algorithm.Within the AFLA-SCNN model,AFLA is employed to optimize two hyperparameters in the SCNN model,namely,“numEpochs”and“miniBatchSize”,to attain their optimal values.AFLA’s performance is initially validated across 28 functions in 10D,30D,and 50D for CEC2013 and 29 functions in 10D,30D,and 50D for CEC2017.Experimental results indicate AFLA’s marked performance superiority over nine other prominent optimization algorithms.Subsequently,the AFLA-SCNN model was compared with the Spectral Convolutional Neural Network model based on Fick’s Law Algorithm(FLA-SCNN),Spectral Convolutional Neural Network model based on Harris Hawks Optimization(HHO-SCNN),Spectral Convolutional Neural Network model based onDifferential Evolution(DE-SCNN),SpectralConvolutionalNeuralNetwork(SCNN)model,and SupportVector Machines(SVM)model using the Indian Pines dataset and PaviaUniversity dataset.The experimental results show that the AFLA-SCNN model outperforms other models in terms of Accuracy,Precision,Recall,and F1-score on Indian Pines and Pavia University.Among them,the Accuracy of the AFLA-SCNN model on Indian Pines reached 99.875%,and the Accuracy on PaviaUniversity reached 98.022%.In conclusion,our proposed AFLA-SCNN model is deemed to significantly enhance the precision of hyperspectral image classification. 展开更多
关键词 Adaptive Fick’s law algorithm spectral convolutional neural network metaheuristic algorithm intelligent optimization algorithm hyperspectral image classification
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Analysis of the Characterization of the Old Man in“The Law of Life”from the Narrative Perspective
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作者 ZHANG Jing-xi 《Journal of Literature and Art Studies》 2024年第4期273-278,共6页
“The Law of Life”is one of Jack London’s representative works,depicting the story of an elderly Native American abandoned by his family,alone and waiting for life to fade away.This paper,based on narrative theory,a... “The Law of Life”is one of Jack London’s representative works,depicting the story of an elderly Native American abandoned by his family,alone and waiting for life to fade away.This paper,based on narrative theory,aims to explore how the author employs narrative techniques to present the image of the old man in the short story.The narrative techniques of dual focalization and dual narrative timelines in the text demonstrate the abandonment of the old man’s homeland and his inescapable death under a naturalistic view of life and reflect a desolate life picture of resignation towards death under naturalistic determinism,depicting a grim elderly world under the naturalistic concept of“survival of the fittest.”Studying this short story helps us reflect on the living conditions of the elderly and provides insights into how to better care for the elderly population amid the global trend of aging. 展开更多
关键词 “The law of Life” focalization narrative time elderly image
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Malawi Opens Tourism Doors No visa’s needed for Chinese tourists and others,as Malawi makes visits more convenient
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作者 EDWIN NYIRONGO 《ChinAfrica》 2024年第5期42-43,共2页
When Malawian President Lazarus Chakwera delivered a State of the Nation Address at the 50th Parliamentary Session and Budget Meeting in February,tourism was top of mind.
关键词 law CONVENIENT Open
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基于Laws与Gabor滤波的田间西兰花花球识别技术 被引量:2
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作者 赵雄 徐港吉 +2 位作者 陈建能 俞高红 代丽 《农业机械学报》 EI CAS CSCD 北大核心 2023年第4期313-322,共10页
正确识别西兰花田间位置是实现西兰花自动化采收的基础,西兰花花球颜色与植株的叶片、茎秆相似,仅通过颜色特征无法对西兰花进行识别,本文以成熟期的田间西兰花为研究对象,提出了一种基于纹理特征与颜色特征的西兰花识别算法。首先通过... 正确识别西兰花田间位置是实现西兰花自动化采收的基础,西兰花花球颜色与植株的叶片、茎秆相似,仅通过颜色特征无法对西兰花进行识别,本文以成熟期的田间西兰花为研究对象,提出了一种基于纹理特征与颜色特征的西兰花识别算法。首先通过预处理以及Laws滤波对图像进行边界纹理强化,再通过Gabor滤波对图像进行纹理特征向量提取,并对提取后的纹理特征向量进行z⁃score标准化,随后对标准化后的纹理特征向量进行K⁃means聚类与开运算,获取花球潜在存在区域。同时对RGB图像进行HSV转换,通过对图像的H分量进行阈值分割达到滤除地面像素的效果。最终对纹理特征识别与颜色特征识别的结果进行融合,实现对田间西兰花的识别。算法通过结合纹理与颜色特征,对田间西兰花进行了识别,解决了西兰花的花球与茎叶等背景颜色相近难以识别的问题。本文共使用792幅图像进行试验,试验结果表明,本方法可以准确地对西兰花田间图像进行识别,其精确率为96.96%,召回率为94.41%,F1值为95.67%。通过对3组不同拍摄环境的数据集进行算法识别,3组数据集的F1值始终保持在94%以上,具有良好的拍摄环境适应性,为农业机器人进行西兰花自动化采收奠定了基础。 展开更多
关键词 图像识别 西兰花 纹理强化 laws滤波 GABOR滤波
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结合Cannikin’s Law的离线数据增广方法研究
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作者 邓雪 赵皓 +2 位作者 张静 梅菠萍 张华 《计算机工程与应用》 CSCD 北大核心 2023年第1期207-212,共6页
数据增广是提升深度学习模型性能的有效方法之一。针对多类别目标检测任务中检测性能不平衡问题,提出一种针对“短板类别”(检测性能远低于模型平均检测性能的类别)的离线数据增广方法。受Cannikin’s Law的启发,采用基于复制粘贴(copy-... 数据增广是提升深度学习模型性能的有效方法之一。针对多类别目标检测任务中检测性能不平衡问题,提出一种针对“短板类别”(检测性能远低于模型平均检测性能的类别)的离线数据增广方法。受Cannikin’s Law的启发,采用基于复制粘贴(copy-paste)机制的场景多样性增广方法。随机采集训练集中“短板类别”实例区域,通过相似性度量机制选取训练集中增广目标样本进行随机粘贴。为了降低随机粘贴导致的遮挡问题,采用基于自遮挡(cut-replace)机制的增广方法提升模型遮挡表达能力。通过截取样本自身区域,对特征表达最显著区域进行遮挡。实验表明,FCOS目标检测框架在PASCAL VOC数据上的平均检测精度(mean average precision,mAP)从79.10%提升到83.90%,其中短板类别更为显著,提升了20.8个百分点。在MS-COCO数据上平均检测精度提升了0.9个百分点。 展开更多
关键词 数据增广 Cannikin’s law 相似性度量机制 自遮挡 目标检测
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Shale oil enrichment evaluation and production law in Gulong Sag,Songliao Basin,NE China 被引量:1
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作者 SUN Longde CUI Baowen +9 位作者 ZHU Rukai WANG Rui FENG Zihui LI Binhui ZHANG Jingya GAO Bo WANG Qingzhen ZENG Huasen LIAO Yuanhui JIANG Hangl 《Petroleum Exploration and Development》 SCIE 2023年第3期505-519,共15页
Based on the results of drilling,tests and simulation experiments,the shales of the Cretaceous Qingshankou Formation in the Gulong Sag of the Songliao Basin are discussed with respect to hydrocarbon generation evoluti... Based on the results of drilling,tests and simulation experiments,the shales of the Cretaceous Qingshankou Formation in the Gulong Sag of the Songliao Basin are discussed with respect to hydrocarbon generation evolution,shale oil occurrence,and pore/fracture evolution mechanism.In conjunction with a substantial amount of oil testing and production data,the Gulong shale oil enrichment layers are evaluated and the production behaviors and decline law are analyzed.The results are drawn in four aspects.First,the Gulong shales are in the stage of extensive hydrocarbon expulsion when R_(0) is 1.0%-1.2%,with the peak hydrocarbon expulsion efficiency of 49.5%approximately.In the low-medium maturity stage,shale oil migrates from kerogen to rocks and organic pores/fractures.In the medium-high maturity stage,shale oil transforms from adsorbed state to free state.Second,the clay mineral intergranular pores/fractures,dissolution pores,and organic pores make up the majority of the pore structure.During the transformation,clay minerals undergo significant intergranular pore/fracture development between the minerals such as illite and illite/smectite mixed layer.A network of pores/fractures is formed by organic matter cracking.Third,free hydrocarbon content,effective porosity,total porosity,and brittle mineral content are the core indicators for the evaluation of shale oil enrichment layers.Class-I layers are defined as free hydrocarbon content equal or greater than 6.0 mg/g,effective porosity equal or greater than 3.5%,total porosity equal or greater than 8.0%,and brittle mineral content equal or greater than 50%.It is believed that the favourable oil layers are Q2-Q3 and Q8-Q9.Fourth,the horizontal wells in the core area of the light oil zone exhibit a high cumulative production in the first year,and present a hyperbolic production decline pattern,with the decline index of 0.85-0.95,the first-year decline rate of 14.5%-26.5%,and the single-well estimated ultimate recovery(EUR)greater than 2.0×10^(4)t.In practical exploration and production,more efforts will be devoted to the clarification of hydrocarbon generation and expulsion mechanisms,accurate testing of porosity and hydrocarbon content/phase of shale under formation conditions,precise delineation of the boundary of enrichment area,relationship between mechanical properties and stimulated reservoir volume,and enhanced oil recovery,in order to improve the EUR and achieve a large-scale,efficient development of shale oil. 展开更多
关键词 Songliao Basin Gulong shale oil Cretaceous Qingshankou Formation hydrocarbon generation and expulsion reservoir pore type pore/fracture formation mechanism enrichment layer evaluation production decline law
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Regularity of Fluxes in Nonlinear Hyperbolic Balance Laws
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作者 Matania Ben-Artzi Jiequan Li 《Communications on Applied Mathematics and Computation》 2023年第3期1289-1298,共10页
This paper addresses the issue of the formulation of weak solutions to systems of nonlinear hyperbolic conservation laws as integral balance laws.The basic idea is that the“meaningful objects”are the fluxes,evaluate... This paper addresses the issue of the formulation of weak solutions to systems of nonlinear hyperbolic conservation laws as integral balance laws.The basic idea is that the“meaningful objects”are the fluxes,evaluated across domain boundaries over time intervals.The fundamental result in this treatment is the regularity of the flux trace in the multi-dimensional setting.It implies that a weak solution indeed satisfies the balance law.In fact,it is shown that the flux is Lipschitz continuous with respect to suitable perturbations of the boundary.It should be emphasized that the weak solutions considered here need not be entropy solutions.Furthermore,the assumption imposed on the flux f(u)is quite minimal-just that it is locally bounded. 展开更多
关键词 Balance laws Hyperbolic conservation laws MULTI-DIMENSIONAL Discontinuous solutions Finite-volume schemes FLUX Trace on boundary
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Zipf’s Law, Benford’s Law, and Pareto Rule
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作者 Oded Kafri 《Advances in Pure Mathematics》 2023年第3期174-180,共7页
From a basic probabilistic argumentation, the Zipfian distribution and Benford’s law are derived. It is argued that Zipf’s law fits to calculate the rank probabilities of identical indistinguishable objects and that... From a basic probabilistic argumentation, the Zipfian distribution and Benford’s law are derived. It is argued that Zipf’s law fits to calculate the rank probabilities of identical indistinguishable objects and that Benford’s distribution fits to calculate the rank probabilities of distinguishable objects. i.e. in the distribution of words in long texts all the words in a given rank are identical, therefore, the rank distribution is Zipfian. In logarithmic tables, the objects with identical 1st digits are distinguishable as there are many different digits in the 2nd, 3rd… places, etc., and therefore the distribution is according to Benford’s law. Pareto 20 - 80 rule is shown to be an outcome of Benford’s distribution as when the number of ranks is about 10 the probability of 20% of the high probability ranks is equal to the probability of the rest of 80% low probability ranks. It is argued that all these distributions, including the central limit theorem, are outcomes of Planck’s law and are the result of the quantization of energy. This argumentation may be considered a physical origin of probability. 展开更多
关键词 Zipf’s law Benford’s law Pareto 20 - 80 Rule Planck’s law Max Entropy
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Aerodynamic shape and drag scaling law of a flexible fibre in a flowing medium
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作者 Bo-Hua Sun Xiao-Lin Guo 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2023年第3期159-163,共5页
The study of a flexible body immersed in a flowing medium is one of the best way to find its aerodynamic shape.This Letter revisited the problem that was first studied by Alben et al.(Nature 420,479–481,2002).To dete... The study of a flexible body immersed in a flowing medium is one of the best way to find its aerodynamic shape.This Letter revisited the problem that was first studied by Alben et al.(Nature 420,479–481,2002).To determine the aerodynamic shape of the fibre,a simpler approach is proposed.A universal drag scaling law is obtained and the universality of the Alben-Shelley-Zhang scaling law is confirmed by using dimensional analysis.A complete Maple code is provided for finding aerodynamic shape of the fibre in the flowing medium. 展开更多
关键词 Flexible fibre Flow medium Aerodynamic shape Drag Scaling law
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