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一种基于改进Refinedet的管道数字射线成像缺陷图像检测方法

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科学技术与工程 2024年第6期24卷 2444-2452页

作者：时亚南马聪张婷陈迎春刘兆英范效礼苗锐新疆维吾尔自治区特种设备检验研究院乌鲁木齐830011 新疆特种设备检测技术研究重点实验室乌鲁木齐830011 北京工业大学信息学部北京100124 北京工业大学城市建设学部北京100124

为提高管道缺陷图像检测的准确率,提出了一种基于改进Refinedet的管道数字射线成像(digital radiography, dr)缺陷图像检测模型。该模型针对管道dr缺陷图像数据少、目标少等特点,从以下三个方面进行改进。首先,在骨干网络设计方面,使用S... 详细信息

为提高管道缺陷图像检测的准确率,提出了一种基于改进Refinedet的管道数字射线成像(digital radiography, dr)缺陷图像检测模型。该模型针对管道dr缺陷图像数据少、目标少等特点,从以下三个方面进行改进。首先,在骨干网络设计方面,使用Swin transformer代替VGG16作为主干网络,在提高特征提取能力的同时减少主干网络参数量。其次,针对管道dr缺陷图像目标数量较少而易受背景干扰问题,通过在主干网络与特征融合阶段之间加入全局注意力模块来强化模型对重要特征的关注,从而提高检测性能。最后,在后处理阶段,针对传统的非最大值抑制算法直接去除非最好预测框问题,使用软非最大值抑制算法以更合理的方式去除非最优预测框。结果表明:该方法能够有效实现管道dr缺陷图像的检测,并且相比于其他4种常用的目标检测模型,提出的模型可以有效提升管道dr缺陷图像检测的准确率,研究结果可为dr缺陷图像检测提供技术支撑。

关键词：目标检测管道数字射线成像缺陷图像 Swin transformer 注意力机制后处理

ON THE CONVERGENCE OF ASYNCHRONOUS NESTEDmaTRIX MULTISPLITTING METHODS FOR LINEARSYSTEMS

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Journal of Computational mathematics 1999年第6期17卷 575-588页

作者： Bai, ZZ Wang, dr Evans, DJ Acad Sinica State Key Lab Sci Engn Comp Inst Computat Math & Sci Engn Comp Beijing 100080 Peoples R China Shanghai Univ Dept Math Shanghai 201800 Peoples R China Loughborough Univ Technol Parallel Algorithms Res Ctr Loughborough LE11 3TU Leics England

A class of asynchronous nested matrix multisplitting methods for solving large-scale systems of linear equations are proposed, and their convergence characterizations are studied in detail when the coefficient matrice... 详细信息

关键词： solution of linear systems asynchronous parallel iteration matrix multisplitting relaxation method convergence

Dynamic compression behavior of TiZrNbV refractory high-entropy alloys upon ultrahigh strain rate loading

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Journal of materials Science & Technology 2023年第30期161卷 201-219页

作者： Kerong Ren Hongyang Liu Rong ma Sen Chen Siyuan Zhang Ruixin Wang Rong Chen Yu Tang Shun Li Fangyun Lu College of Sciences National University of Defense TechnologyChangsha 410008China Aviation maintenance NCO Academy Air Force Engineering UniversityXinyang 464001China The Peac Institute of Multiscale Sciences Chengdu 610031China College of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410008China

In this study,the dynamic compressive response behavior of a body-centered cubic(BCC)single-phase TiZrNbV refractory high-entropy alloy(RHEA)was investigated under impact at speeds of 313-1584 m s^(-1)using two-stage,gas-gun-driven,high-speed plate-impact experiments;recovery sample analysis;and theoretical *** strain rate and pressure were approximately 10^(7) s^(−1) and 5.07-29.37 GPa,*** results showed that the TiZrNbV RHEA had a Hugoniot elastic limit of 4.12-5.86 GPa and a spall strength of 1.84-2.03 *** initial yield strength of the alloy showed a strong strain-rate dependence and could be described by the modified Zerilli-Armstrong model,while the phonon-damping effect was the main reason for its high strain-rate *** analysis showed that the dynamic deformation of the TiZrNbV RHEA was controlled by the dislocation slip,dislocation proliferation,intersection of the deformation bands,and grain *** analysis also showed that the intergranular,transgranular,and mixed-type cracks dominated the spall failure of the *** dynamic Hall-Petch effect and pinning from the lattice distortion led to high dynamic yield *** critical strain rate for the phonon drag effect was positively related to the relative atomic mass and local strain field of the *** the experimental loading range,the RHEA showed good structural stability,and simultaneously,the theoretical calculation method for the equation of state based on a cold-energy mixture could accurately predict its shock-response *** valence-electron concentration(VEC)had a direct effect on the shock-compression properties of the HEAs;higher VEC implied more difficulty in compressing the *** findings of this study provide insights into understanding the mechanical response characteristics of RHEAs under extreme conditions such as high-speed impact and ultrahigh strain-rate loading.

关键词： Refractory high-entropy alloys Shock compression Spall Dynamic yield Equation of state Ultrahigh strain rate

Hepatic angiomyolipoma-misdiagnosis as hepatocellular carcinoma:A report of 14 cases

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World Journal of Gastroenterology 2000年第4期6卷 608-612页

作者： Zhong dr Ji XL Gen Hosp PLA Dept Pathol Beijing 100853 Peoples R China

INTRODUCTIONAngiomyolipoma(AML)is a rare benign mesenchymaltumor of the liver,composed of a varying heterogeneousmixture of three tissue components:blood vessels。

关键词： angiomyolipoma liver neoplasms/diagnosis immunohistochemistry microscopy electron carcinoma hepatocellular/pathology case-control studies

Tips for maintaining a Healthy Thyroid

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城市漫步（GBA版） 2023年第7期 38-39页

作者： dr.Neil 不详

The incidence and prevalence of thyroiddiseases have been increasing in *** people are diagnosed with thyroid nodules orthyroid dysfunction.

关键词： diseases prevalence Healthy

Focal-type,but not Diffuse-type,Amyloid Beta Plaques are Correlated with Alzheimer’s Neuropathology,Cognitive Dysfunction,and Neuroinflammation in the Human Hippocampus

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Neuroscience Bulletin 2022年第10期38卷 1125-1138页

作者： Fan Liu Jianru Sun Xue Wang Sixuan Jin Fengrun Sun Tao Wang Bo Yuan Wenying Qiu Chao ma National Human Brain Bank for development and Function School of Basic Medicine Peking Union Medical CollegeInstitute of Basic Medical Sciences Chinese Academy of Medical SciencesBeijing 100005China department of Human Anatomy Histology and EmbryologyNeuroscience CenterSchool of Basic Medicine Peking Union Medical CollegeInstitute of Basic Medical Sciences Chinese Academy of Medical SciencesBeijing 100005China Chinese Institute for Brain Research Beijing 102206China

Amyloid beta(Aβ)plaques are one of the hallmarks of Alzheimer’s disease(AD).However,currently available anti-amyloid therapies fail to show effectiveness in the treatment of AD in *** has been found that there are different types of Aβplaque(diffuse and focal types)in the postmortem human *** this study,we aimed to investigate the correlations among different types of Aβplaque and AD-related neuropathological and cognitive changes based on a postmortem human brain bank in *** results indicated that focal plaques,but not diffuse plaques,significantly increased with age in the human *** also found that the number of focal plaques was positively correlated with the severity of AD-related neuropathological changes(measured by the“ABC”scoring system)and cognitive decline(measured by the Everyday Cognitive Insider Questionnaire).Furthermore,most of the focal plaques were co-localized with neuritic plaques(identified by Bielschowsky silver staining)and accompanied by microglial and other inflammatory *** findings suggest the potential of using focal-type but not general Aβplaques as biomarkers for the neuropathological evaluation of AD.

关键词： Focal Aβ plaques ECog score ABC score Alzheimer’s disease Neuroinflammation Clinicopathological correlation Human brain bank

Comparison of Different Generation Mechanisms of Free Convection between Two Stations on the Tibetan Plateau

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Advances in Atmospheric Sciences 2018年第9期35卷 1137-1144页

作者： Lang ZHANG Yaoming ma Weiqiang ma Binbin WANG Key Laboratory of Tibetan Environment Changes and Land Surface Processes Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China CAS Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of SciencesBeijing 100101China

Based on high-quality data from eddy covariance measurements at the Qomolangma Monitoring and Research Station for Atmosphere and Environment（QOMS） and the Southeast Tibet Monitoring and Research Station for Environment（SETS）,near-ground free convection conditions（FCCs） and their characteristics are investigated. At QOMS, strong thermal effects accompanied by lower wind speeds can easily trigger the occurrence of FCCs. The change of circulation from prevailing katabatic glacier winds to prevailing upslope winds and the oscillation of upslope winds due to cloud cover are the two main causes of decreases in wind speed at QOMS. The analysis of results from SETS shows that the most important trigger mechanism of FCCs is strong solar heating. Turbulence structural analysis using wavelet transform indicates that lowerfrequency turbulence near the ground emerges from the detected FCCs both at QOMS and at SETS. It should be noted that the heterogeneous underlying surface at SETS creates large-scale turbulence during periods without the occurrence of FCCs. Regarding datasets of all seasons, the distribution of FCCs presents different characteristics during monsoonal and non-monsoonal periods.

关键词： free convection conditions eddy covariance complex terrain Tibetan Plateau

METABOLIC AND TRANSCRIPTOME ANALYSIS REVEALS METABOLITE VARIATION AND FLAVONOID REGULATORY NETWORKS IN FRESH SHOOTS OF TEA(CAMELLIA SINENSIS)OVER THREE SEASONS

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Frontiers of Agricultural Science and Engineering 2021年第2期8卷 215-230页

作者： Chen-Kai JIANG de-Jiang NI Ming-Zhe YAO Jian-Qiang ma Liang CHEN Key Laboratory of Tea Biology and Resources Utilization Ministry of Agriculture and Rural AffairsTea Research Institute of the Chinese Academy of Agricultural SciencesHangzhou 310008China State Key Laboratory for Quality and Safety of Agro-products Zhejiang Academy of Agricultural SciencesHangzhou 310021China College of Horticulture and Forestry Science Huazhong Agricultural UniversityWuhan 430070China.

Metabolites,especially secondary metabolites,are very important in the adaption of tea plants and the quality of tea ***,we focus on the seasonal variation in metabolites of fresh tea shoots and their regulatory mechanism at the transcriptional *** metabolic profiles of fresh tea shoots of 10 tea accessions collected in spring,summer,and autumn were analyzed using ultra-performance liquid chromatography coupled with quadrupole-obitrap mass *** focused on the metabolites and key genes in the phenylpropanoid/flavonoid pathway integrated with transcriptome *** statistical analysis indicates that metabolites were distinctly different with seasonal ***,amino acids,organic acids and alkaloids were the predominant *** of most key genes and downstream compounds in the flavonoid pathway were lowest in spring but the catechin quality index was highest in *** regulatory pathway was explored by constructing a metabolite correlation network and a weighted gene co-expression network.

关键词： harvest season metabolites tea shoots profiled.Mulhvanale statistics transcriptomics untargeted metabolomics

decision tree and deep learning based probabilistic model for character recognition

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Journal of Central South University 2017年第12期24卷 2862-2876页

作者： A.K.Sampath dr.N.Gomathi Rizvi College of Engineering MumbaiMaharashtra 400050India Veltech dr.R.R&dr.S.R.Technical University Avadi Chennai-600 062India

One of the most important methods that finds usefulness in various applications, such as searching historical manuscripts, forensic search, bank check reading, mail sorting, book and handwritten notes transcription, is handwritten character recognition. The common issues in the character recognition are often due to different writing styles, orientation angle, size variation(regarding length and height), etc. This study presents a classification model using a hybrid classifier for the character recognition by combining holoentropy enabled decision tree(HDT) and deep neural network(DNN). In feature extraction, the local gradient features that include histogram oriented gabor feature and grid level feature, and grey level co-occurrence matrix(GLCM) features are extracted. Then, the extracted features are concatenated to encode shape, color, texture, local and statistical information, for the recognition of characters in the image by applying the extracted features to the hybrid classifier. In the experimental analysis, recognition accuracy of 96% is achieved. Thus, it can be suggested that the proposed model intends to provide more accurate character recognition rate compared to that of character recognition techniques used in the literature.

关键词： grey level co-occurrence matrix feature histogram oriented gabor gradient feature hybrid classifier holoentropy enabled decision tree classifier