检索结果-南通市图书馆

Journal of Rock Mechanics and Geotechnical Engineering 2023年第7期15卷 1797-1809页

作者： Yao Xiao Jia Yu Guoxin Xu Dawei Tong Jiahao Yu tuocheng zeng State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin300072China Hanjiang to Weihe River Valley Water Diversion Project Construction Co. Ltd.Xi’an710024China

Estimation of construction parameters is crucial for optimizing tunnel construction *** to the influence of routine activities and occasional risk events,these parameters are usually correlated and *** solve this issue,an improved bidirectional generative adversarial network(BiGAN)model with a joint discriminator structure and zero-centered gradient penalty(0-GP)is *** this model,in order to improve the capability of original BiGAN in learning imbalanced parameters,the joint discriminator separately discriminates the routine activities and risk event durations to balance their influence ***,the self-attention mechanism is embedded so that the discriminator can pay more attention to the imbalanced ***,the 0-GP is adapted for the loss of the discrimi-nator to improve its convergence and stability.A case study of a tunnel in China shows that the improved BiGAN can obtain parameter estimates consistent with the classical Gauss mixture model,without the need of tedious and complex correlation *** proposed joint discriminator can increase the ability of BiGAN in estimating imbalanced construction parameters,and the 0-GP can ensure the stability and convergence of the model.

关键词： Multivariate parameters estimation Correlated and imbalanced parameters Bidirectional generative adversarial network(BiGAN) Joint discriminator Zero-centered gradient penalty(0-GP)

基于大场景视频监控的坝面施工机械潜在碰撞风险预警方法

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

水利学报 2024年第7期55卷 780-790,801页

作者：曾拓程王佳俊钟登华张雨诺康栋天津大学水利工程智能建设与运维全国重点实验室天津300350 中国农业大学水利与土木工程学院北京100083 雅砻江流域水电开发有限公司四川成都610051

基于大场景视频监控实现坝面施工机械潜在碰撞风险预警对保证大坝施工安全具有重要意义。然而,目前坝面施工机械潜在碰撞风险检测主要依赖人工经验判断,易出现漏判和误判等问题。因此,本研究提出一种基于大场景视频监控的坝面施工机械... 详细信息

基于大场景视频监控实现坝面施工机械潜在碰撞风险预警对保证大坝施工安全具有重要意义。然而,目前坝面施工机械潜在碰撞风险检测主要依赖人工经验判断,易出现漏判和误判等问题。因此,本研究提出一种基于大场景视频监控的坝面施工机械潜在碰撞风险预警方法。首先,基于Trajectron++轨迹预测算法,通过迁移学习,实现对坝面大场景视频监控中数量众多、类型多样的施工机械在未来一段时间内的轨迹预测。其次,提出将行驶接近时间和机械最大拥挤度作为坝面施工机械潜在碰撞风险的量化指标,并基于模糊规则,建立不同行驶速度条件下两个指标与潜在碰撞风险分级预警的模糊隶属度函数。最后,采用证据理论对两个指标的预警结果进行融合,计算最终的预警等级。以两河口大坝施工现场的大场景视频监控为例进行实验验证,结果表明坝面施工机械未来6 s的轨迹预测平均位移误差和最终位移误差分别为1.17和2.36 m,且基于模糊-证据融合的施工机械潜在碰撞风险分级预警结果可为坝面施工安全提供自动化、智能化分析方法。

关键词：施工机械安全大场景视频监控轨迹预测模糊-证据融合分级预警

大场景视频监控下大坝运输车改进多目标多视觉卸料识别模型研究

维普期刊数据库

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

水利学报 2023年第5期54卷 519-529,540页

作者：曾拓程王佳俊王晓玲张雨诺康栋天津大学水利工程仿真与安全国家重点实验室天津300350 雅砻江流域水电开发有限公司四川成都610051

运输车卸料识别对保障大坝施工安全、优化运输配置具有重要意义。然而,大坝施工中多采用全球导航卫星系统(Global Navigation Satellite System,GNSS)进行运输车活动状态分析,存在设备成本高、识别精度低等缺点。目前,通过布设高清摄像... 详细信息

运输车卸料识别对保障大坝施工安全、优化运输配置具有重要意义。然而,大坝施工中多采用全球导航卫星系统(Global Navigation Satellite System,GNSS)进行运输车活动状态分析,存在设备成本高、识别精度低等缺点。目前,通过布设高清摄像头进行坝面大场景施工监控成为趋势,但尚未见基于机器视觉的运输车卸料识别研究。针对上述问题,提出大场景视频监控下大坝施工运输车卸料识别改进多目标多视觉任务模型。首先,采用ByteTrack实现大场景监控视频中多辆运输车目标检测与追踪,记录其行驶轨迹;其次,High Resolution Net(HRNet)被用于运输车头部和尾部的关键点检测,进而结合行驶轨迹判断运输车前进、停止和后退等行进状态;再者,通过Destruction and Construction Learning(DCL)细粒度分类方法判断运输车料斗的抬升状态;最后,结合ByteTrack、HRNet和DCL的多目标多视觉任务的分析结果判定运输车卸料状态。以两河口施工视频监控为例进行验证,提出的卸料识别模型在34帧时卸料状态识别平均准确率为87.3%,卸料时间判断精度为90.3%,验证了本模型的可行性和有效性。

关键词：卸料识别大场景视频监控多目标跟踪关键点检测细粒度分类

维普期刊数据库博看期刊

贝叶斯框架下大坝渗流参数反演组合代理模型研究

在线全文

学校读者我要写书评

暂无评论

水利学报 2022年第3期53卷 306-315,324页

作者：余红玲王晓玲王成曾拓程余佳盖世聪天津大学水利工程仿真与安全国家重点实验室天津300072 天津市政工程设计研究总院有限公司天津300051

渗流参数贝叶斯反演的关键在于解决对渗流正演模型大量调用而导致的计算耗时问题。现有提高贝叶斯反演计算效率的研究大多采用基于单一机器学习算法的代理模型,计算精度较低。针对上述问题,本文提出一种贝叶斯框架下大坝渗流参数反演组... 详细信息

渗流参数贝叶斯反演的关键在于解决对渗流正演模型大量调用而导致的计算耗时问题。现有提高贝叶斯反演计算效率的研究大多采用基于单一机器学习算法的代理模型,计算精度较低。针对上述问题,本文提出一种贝叶斯框架下大坝渗流参数反演组合代理模型。该方法在贝叶斯框架下集成支持向量回归(SVR)、Kriging和多元自适应回归样条(MARS)三种机器学习算法。其中,利用差分进化自适应Metropolis(DREAMZS)算法并行采样的优势计算权重系数的随机分布函数,在考虑不确定性的条件下获得模型权重系数。案例分析表明,相比于运行一次至少需要耗费4 h的渗流数值模型,本文所提组合代理模型运行一次仅需几秒钟,显著提高了贝叶斯反演的计算效率;此外,本文所提反演方法相比于基于SVR、Kriging和MARS的贝叶斯反演方法能够获得更准确的反演结果,其平均精度分别提高了13.78%、19.34%和12.27%,为大坝渗流参数反演提供了一种新思路。

关键词：渗流参数贝叶斯反演组合代理模型 DREAMZS算法 SVR Kriging MARS

维普期刊数据库博看期刊

Advances in genotypic antimicrobialresistance testing: a comprehensive review

在线全文

学校读者我要写书评

暂无评论

Science China Life Sciences 2025年第1期68卷 130-143页

作者： Boheng Duan Xianjun zeng Junping Peng Huan Kui College of Nanchang University Department of Imaging The Second Affiliated Hospital of Nanchang University NHC Key Laboratory of Systems Biology of Pathogens National Institute of Pathogen BiologyChinese Academy of Medical Sciences & Peking Union Medical College Key Laboratory of Respiratory Disease Pathogenomics Chinese Academy of Medical Sciences & Peking Union Medical College Key Laboratory of Pathogen Infection Prevention and Control (Ministry of Education) State Key Laboratory of Respiratory Health and MultimorbidityNational Institute of Pathogen BiologyChinese Academy of Medical Sciences & Peking Union Medical College

Antimicrobial resistance(AMR) represents a substantial threat to global public health, complicating the treatment of common infections and leading to prolonged illness and escalated healthcare expenses. To effectively combat AMR, timely and accurate detection is crucial for AMR surveillance and individual-based therapy. Phenotypic antibiotic resistance testing(AST) has long been considered the gold standard in clinical applications, serving as the foundation for clinical AMR diagnosis and optimized therapy. It has significantly contributed to ensuring patients′ health and the development of novel antimicrobials. Despite advancements in automated culture-based AST technologies,inherent limitations impede the widespread use of phenotypic AST in AMR surveillance. Genotypic AST technologies offer a promising alternative option, exhibiting advantages of rapidity, high sensitivity, and specificity. With the continuous advancement and expanding applications of genotypic AST technologies, such as microfluidics, mass spectrometry, and high-resolution melting curve analysis, new vigor has been injected into the development and clinical implementation of genotypic AST technologies. In this narrative review, we discuss the principles, applications, and advancements of emerging genotypic AST methods in clinical settings. The comprehensive review aims to highlight the significant scientific potential of emerging genotypic AST technologies in clinical AMR diagnosis, providing insights to enhance existing methods and explore novel approaches.

关键词： antimicrobial resistance (AMR) genotypic antibiotic resistance testing (AST) AST technologies review

Copper-catalyzed C–H bond functionalization enabled by programmed alternating current

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2025年第1期68卷 10-11页

作者： Zhoumei Tan Kun Xu Chengchu zeng Beijing Key Laboratory of Environmental and Viral Oncology College of Chemistry and Life Science Beijing University of Technology

Synthetic electrochemistry has been selected as one of the Top Ten Emerging Technologies in Chemistry in 2023 by International Union of Pure and Applied Chemistry (IUPAC)[1]. It has emerged as a sustainable platform for organic synthesis and has exhibited a wide range of applications from academia to industry [2]. However, electrosynthesis has been predominantly performed by using direct current (DC).

关键词：

高心墙堆石坝大场景视频监控网络覆盖NCHHO优化

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

水力发电学报 2022年第7期41卷 47-60页

作者：康栋张君王佳俊王晓玲赵豪曾拓程瞿晓峰天津大学水利工程仿真与安全国家重点实验室天津300072

覆盖率和成本是衡量高心墙堆石坝视频监控网络部署优劣的重要指标。然而,现有研究缺乏对建设成本的综合考虑,且常用的视频监控网络覆盖优化求解方法存在收敛速度慢、易陷入局部最优等不足。针对上述问题,本文提出一种高心墙堆石坝大场... 详细信息

覆盖率和成本是衡量高心墙堆石坝视频监控网络部署优劣的重要指标。然而,现有研究缺乏对建设成本的综合考虑,且常用的视频监控网络覆盖优化求解方法存在收敛速度慢、易陷入局部最优等不足。针对上述问题,本文提出一种高心墙堆石坝大场景视频监控网络覆盖改进哈里斯鹰优化模型——非线性混沌哈里斯鹰优化(nonlinear chaotic Harris hawks optimization,NCHHO)模型。首先,提出表征视频网络部署成本的单位摄像头重复采样率指标,并基于集合覆盖理论构建以覆盖率和单位摄像头重复采样率最大为目标的视频监控网络覆盖优化模型。其次,利用混沌序列和非线性能量更新策略改进哈里斯鹰算法的种群初始化和搜索过程,提高算法的收敛速度、避免陷入早熟,并利用其求解视频监控网络覆盖优化模型。实例验证了改进哈里斯鹰算法在视频监控网络部署优化中的有效性和优越性,本研究得到的优化方案覆盖率和重复采样点比例分别为99.98%和60.3%,相比经验方案提高了13.8%和23.2%,显著优化了视频监控效果。

关键词：高心墙堆石坝视频监控网络覆盖改进哈里斯鹰优化算法集合覆盖单位摄像头重复采样率

维普期刊数据库

Experimental Study on Geometry Characteristics of Turbulent Premixed Flames for Natural Gas/Air Mixtures

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2025年第1期34卷 268-282页

作者： ZHENG Weilin WANG Qijiao XIAO Huahua CHEN Xiaoxiao XIE Fan zeng Wen Liaoning Key Lab of Advanced Test Technology for Aerospace Propulsion System Shenyang Aerospace University State Key Laboratory of Fire Science University of science and Technology of China AVIC Shenyang Aircraft Design and Research Institute

In this study,focusing on the geometry characteristics of spherical expanding flame,the turbulent premixed flames of natural gas/air mixtures were investigated in a fan-stirred turbulent *** effects of initial temperature（T=300-400 K）,initial pressure（P=0.1-0.3 MPa）,turbulence intensity（u'=1.0-2.7 m/s）,oxygen volumetric percentage(φ（O2）=15%-21%) and carbon dioxide volumetric percentage(φ（CO2）=0-20%)were delved *** flame profile under the Cartesian coordinate system was derived from the schlieren images taken by the high-speed ***,from both macroscopic and microscopic perspectives,the influence of experimental conditions on the flame geometry characteristics was explored through flame front extraction,wavelet decomposition and network *** results demonstrate that for significant flame wrinkling,changes in species concentrations and turbulence intensity have more pronounced effects on the flame wrinkling *** wrinkling of the flame front maintains a certain degree of similarity,as evidenced by the locally concentrated distribution of the angles of the maximum fluctuation *** disturbance energy under large-scale（D6-D8） disturbances exhibits relatively high values with a similar trend,exerting a significant impact on the geometry characteristics of the flame *** peaks of correlation degree are scattered either with the decomposition scale or the development of flame radius,indicating no linear correlation between different detail ***,the probability distribution of node degrees in key wrinkled regions exhibits different trends with that of large-scale wrinkling and disturbance energy,especially with changes in initial *** occurs because the number of key wrinkles varies based on the perturbation's strength or the region's ***,an increase in the fluctuation frequency of the flame's local radius may not necessarily lead to an increase in the number of key folded regions.

关键词： fan-stirred turbulent combustor geometry characteristics large-scale wrinkling network topology wavelet decomposition

Inexact proximal gradient algorithm with random reshuffling for nonsmooth optimization

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2025年第1期68卷 219-237页

作者： Xia JIANG Yanyan FANG Xianlin zeng Jian SUN Jie CHEN National Key Lab of Autonomous Intelligent Unmanned Systems School of AutomationBeijing Institute of Technology Beijing Institute of Technology Chongqing Innovation Center School of Electronic and Information Engineering Tongji University

Proximal gradient algorithms are popularly implemented to achieve convex optimization with nonsmooth regularization. Obtaining the exact solution of the proximal operator for nonsmooth regularization is challenging because errors exist in the computation of the gradient; consequently, the design and application of inexact proximal gradient algorithms have attracted considerable attention from researchers. This paper proposes computationally efficient basic and inexact proximal gradient descent algorithms with random reshuffling. The proposed stochastic algorithms take randomly reshuffled data to perform successive gradient descents and implement only one proximal operator after all data pass through. We prove the convergence results of the proposed proximal gradient algorithms under the sampling-without-replacement reshuffling *** computational errors exist in gradients and proximal operations, the proposed inexact proximal gradient algorithms can converge to an optimal solution neighborhood. Finally, we apply the proposed algorithms to compressed sensing and compare their efficiency with some popular algorithms.

关键词： proximal operator random reshuffling inexact computation compressed sensing nonsmooth optimization

Brain region-specific roles of brain-derived neurotrophic factor in social stress-induced depressive-like behavior

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第1期20卷 159-173页

作者： Man Han Deyang zeng Wei Tan Xingxing Chen Shuyuan Bai Qiong Wu Yushan Chen Zhen Wei Yufei Mei Yan zeng Brain Science and Advanced Technology Institute Wuhan University of Science and TechnologyWuhanHubei ProvinceChina Geriatric Hospital Affiliated to Wuhan University of Science and Technology WuhanHubei ProvinceChina School of Public Health Wuhan University of Science and TechnologyWuhanHubei ProvinceChina

Brain-derived neurotrophic factor is a key factor in stress adaptation and avoidance of a social stress behavioral *** studies have shown that brain-derived neurotrophic factor expression in stressed mice is brain region–specific,particularly involving the corticolimbic system,including the ventral tegmental area,nucleus accumbens,prefrontal cortex,amygdala,and *** how brain-derived neurotrophic factor participates in stress processing in different brain regions will deepen our understanding of social stress *** this review,we discuss the expression and regulation of brain-derived neurotrophic factor in stress-sensitive brain regions closely related to the pathophysiology of *** focused on associated molecular pathways and neural circuits,with special attention to the brain-derived neurotrophic factor–tropomyosin receptor kinase B signaling pathway and the ventral tegmental area–nucleus accumbens dopamine *** determined that stress-induced alterations in brain-derived neurotrophic factor levels are likely related to the nature,severity,and duration of stress,especially in the above-mentioned brain regions of the corticolimbic ***,BDNF might be a biological indicator regulating stress-related processes in various brain regions.

关键词： amygdala chronic mild stress chronic social defeat stress corticolimbic system depression hippocampus medial prefrontal cortex nucleus accumbens social stress models ventral tegmental area

维普期刊数据库