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A Composite Transformer-Based Multi-Stage Defect Detection Architecture for Sewer Pipes

Computers, Materials & Continua 2024年第1期78卷 435-451页

作者： zifeng yu Xianfeng Li Lianpeng Sun Jinjun Zhu Jianxin Lin School of Computer Science and Engineering Macao University of Science and TechnologyMacao999078China School of Environmental Science and Engineering Sun Yat-sen UniversityGuangzhou510275China Guangdong AIKE Environmental Science and Technology Co. Ltd.Zhongshan528400China

Urban sewer pipes are a vital infrastructure in modern cities,and their defects must be detected in time to prevent potential *** recent years,to relieve the manual efforts by human experts,models based on deep learning have been introduced to automatically identify potential ***,these models are insufficient in terms of dataset complexity,model versatility and *** work addresses these issues with amulti-stage defect detection architecture using a composite backbone Swin *** based on this architecture is trained using a more comprehensive dataset containingmore classes of *** ablation studies on the modules of combined backbone Swin Transformer,multi-stage detector,test-time data augmentation and model fusion,it is revealed that they all contribute to the improvement of detection accuracy from different *** model incorporating all these modules achieves the mean Average Precision(mAP)of 78.6% at an Intersection over Union(IoU)threshold of *** represents an improvement of 14.1% over the ResNet50 Faster Region-based Convolutional Neural Network(R-CNN)model and a 6.7% improvement over You Only Look Once version 6(YOLOv6)-large,the highest in the YOLO *** addition,for other defect detection models for sewer pipes,although direct comparison with themis infeasible due to the unavailability of their private datasets,our results are obtained from a more comprehensive dataset and have superior generalization capabilities.

关键词： Sewer pipe defect detection deep learning model optimization composite transformer

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Recent advances in landfalling tropical cyclone asymmetric rainfall mechanism and forecast verification over China

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TROPICAL CYCLONE RESEARCH AND REVIEW 2024年第1期13卷 33-40页

作者： yu, zifeng Chen, Peiyan Ren, Fumin Tang, Lichun Wang, Weiwei yu, Hui Zhao, Kun China Meteorol Adm Shanghai Typhoon Inst Shanghai Peoples R China Typhoon Collaborat Res Ctr Shanghai Peoples R China Chinese Acad Meteorol Sci Beijing Peoples R China Nanjing Univ Informat Sci & Technol Nanjing Peoples R China Nanjing Univ Nanjing Peoples R China

Held every four years, the International Workshop on Tropical Cyclone (IWTC) organized by the World Meteorological Organization has been a global leading conference in the field of tropical cyclone. In preparation for the 10th IWTC (IWTC-10) in December 2022, a summary of research advances of landfalling tropical cyclone (LTC) rainfall during past four years of 2019-2022 has been prepared. Some of the latest research advances has been summarized in Lamers et al. (2023), which reviewed the latest forecast and disaster prevention methods related to TC precipitation. As a supplement, this article mainly focuses on the recent advances in LTC asymmetric rainfall evolution mechanisms and forecast verification results over China. Some new findings have been made in the LTC inner-core size relationship with the asymmetric rainfall distribution. Some major advances focused on asymmetric microphysical characteristics in the TC rainbands. Current simulation and forecast performances of LTC precipitation have been analyzed, and different forecast error sources for rainfall during different landfall stages of TC were compared. To estimate the risk of TC rainfall hazards in China, a parameterized Tropical Cyclone Precipitation Model was reviewed as well in this article. (c) 2024 The Shanghai Typhoon Institute of China Meteorological Administration. Publishing services by Elsevier B.V. on behalf of KeAi Communication Co. Ltd. This is an open access article under the CC BY license (http://***/licenses/by/4.0/).

关键词： Tropical cyclone Landfall Rainfall Precipitation forecast verification PRECIPITATION

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Tropical cyclone activities in the Western North Paci fi c in 2022

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TROPICAL CYCLONE RESEARCH AND REVIEW 2024年第2期13卷 125-135页

作者： Huang, Xin Bai, Lina yu, zifeng Chan, Johnny C. L. yu, Hui Tang, Jie Guo, Rong Wan, Rijin China Meteorol Adm Shanghai Typhoon Inst Shanghai 200030 Peoples R China Asia Pacific Typhoon Collaborat Res Ctr Shanghai Peoples R China City Univ Hong Kong Sch Energy & Environm Hong Kong Peoples R China

Based on the best-track dataset from the Shanghai Typhoon Institute/China Meteorological Administration, the paper provides a comprehensive summary and analysis of tropical cyclone (TC) activities in the Western North Pacific (WNP) and the South China Sea (SCS) for 2022. Using the historical climatology from 1951 to 2020, the anomalous conditions during 2022 in TC frequency, origin locations, tracks, intensity, and duration for the entire ocean basin as well as landfall events in China are examined. Results show that the overall TC frequency is slightly lower than normal, but the multiple TC events have a very high frequency of occurrence. Origin locations of TCs, which mark the starting points of their paths, show a large westward and northward deviation from climatology. Around 40% of the named TCs exhibit a shift in their direction of movement from westerly to easterly. Additionally, comparisons of the means, medians, upper and lower quartiles all indicate that the intensity of TCs in 2022 is generally lower than the climatology, with the duration of TCs at tropical storm intensity or above being shorter than usual. A notable observation is the fewer incidence of TC landfalls in China, but with a geographical concentration in Guangdong Province. These anomalous annual TC activities are influenced by related atmospheric and oceanic environmental conditions modulated by multi-scale climate variability. The findings provide useful information for enhancing disaster mitigation strategies in the Asia-Pacific region. (c) 2024 The Shanghai Typhoon Institute of China Meteorological Administration. Publishing services by Elsevier B.V. on behalf of KeAi Communication Co. Ltd. This is an open access article under the CC BY-NC-ND license (http://***/licenses/by-nc-nd/4.0/).

关键词： Tropical cyclone Western North Paci fi c Anomalous characteristics Annual report TYPHOON COMMITTEE REGION EL-NINO INTERANNUAL VARIABILITY INTERDECADAL VARIATIONS GENESIS FREQUENCY 3RD ASSESSMENT CLIMATE-CHANGE ENSO OSCILLATION INTENSITY

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Application of the frequency-matching method in the probability forecast of landfalling typhoon rainfall

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Frontiers of Earth Science 2022年第1期16卷 52-63页

作者： Rong GUO Hui yu zifeng yu Jie TANG Lina BAI Shanghai Typhoon Institute and Key Laboratory of Numerical Modeling for Tropical Cyclone of China Meteorological AdministrationShanghai 200030China

In this paper,a revised method for typhoon precipitation probability forecast,based on the frequencymatching method,is developed by combining the screening and the neighborhood *** frequency of the high-resolution precipitation forecasts is used as the reference frequency,and the frequency of the lowresolution ensemble forecasts is used as the forecast *** on frequency–matching method,the frequency of rainfall above the rainstorm magnitude *** forecast members are then selected by using the typhoon tracks of the short-term predictions,and the precipitation probability is calculated for each member using a combination of the neighbor and the traditional probability statistical ***,four landfalling typhoons(i.e.,STY Lekima and STS Bailu in 2019,and TY Hagupit and Higos in 2020)were chose to test the rainfall probability *** results show that the method performs well with respect to the forecast rainfall area and magnitude for the four *** Brier and Brier skill scores are almost entirely positive for the probability forecast of 0.1–250 mm rainfall during Bailu,Hagupit and Higos(except for 0.1mm of Hagupit),and for<100 mm rainfall(except for 25 mm)during Lekima.

关键词： frequency-matching method landfalling typhoon rainfall probability Brier score

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离心泵内不稳定流动及流致噪声特性研究

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舰船科学技术 2024年第17期46卷 27-33页

作者：李华李琛琦于子峰郭超古自强董亮国家石油天然气管网集团有限公司河北廊坊300457 江苏大学流体机械工程技术研究中心江苏镇江212013

为了提高船用离心泵性能和振动噪声控制目标,从而优化舰船隐蔽巡航能力,本文搭建离心泵试验台,对不同工况下泵的性能、压力脉动和流动噪声进行测量分析,通过对比试验和数值计算结果验证数值算法的准确性,结合CFD-FEM方法对船用泵内剪应... 详细信息

为了提高船用离心泵性能和振动噪声控制目标,从而优化舰船隐蔽巡航能力,本文搭建离心泵试验台,对不同工况下泵的性能、压力脉动和流动噪声进行测量分析,通过对比试验和数值计算结果验证数值算法的准确性,结合CFD-FEM方法对船用泵内剪应力、湍动能、压力脉动和流阻及流致噪声特性进行分析。结果表明,叶片出口处壁面剪应力和湍动能较大,在叶片出口处1/3区域内摩擦阻力更大,压力脉动在叶频及其倍频处有明显峰值,呈现出明显地离散特征。内场噪声在整个频率带内表现为宽频特征,并且当频率增加,声压降低。在1000 Hz以内频段声压级能量较高,在叶片频率(241.7 Hz)及其倍频处能观察到特征峰值。总声压级随着流量的增加而呈现出先减小后增加的趋势。

关键词：离心泵船用泵不稳定流动内场噪声

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基于FLAC3D的开采扰动下巷道稳定性研究

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金属矿山 2024年第8期 59-63页

作者：张武赵兴东于文龙秦绍龙胡学平于梓丰北方矿业有限责任公司北京100053 深部金属矿采动地压灾害防控国家矿山安全监察局重点实验室辽宁沈阳110819

近矿体巷道围岩稳定性与开采扰动密切相关,本文以大柴旦矿业有限公司青龙沟北矿段深部西矿体及3280北风井回风巷道为主要研究对象,基于现场地质调查和室内岩石力学试验,对岩体质量进行分级和岩体力学参数进行估算;依据矿山生产计划,建... 详细信息

近矿体巷道围岩稳定性与开采扰动密切相关,本文以大柴旦矿业有限公司青龙沟北矿段深部西矿体及3280北风井回风巷道为主要研究对象,基于现场地质调查和室内岩石力学试验,对岩体质量进行分级和岩体力学参数进行估算;依据矿山生产计划,建立数值计算模型,分析位移规律及采动应力演化过程。结果表明:随着深部西矿体开采工作的进行,巷道变形整体较小,并向采场方向倾斜移动;随着开采深度增加巷道右帮、拱肩应力集中区域与顶板应力较低区域呈顺时针转动,在开采完5个中段后后续矿体的开采对巷道周围应力分布影响较小;3280北风井回风巷道及左侧斜坡道、二者间联络道出现了应力集中现象,针对千枚岩岩体质量较差应在全面了解该区域岩体质量后进行支护优化设计。

关键词：稳定性分析数值模拟巷道变形采动应力

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Rainfall forecast errors in different landfall stages of Super Typhoon Lekima (2019)

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Frontiers of Earth Science 2022年第1期16卷 34-51页

作者： Bin HE zifeng yu Yan TAN Yan SHEN Yingjun CHEN Shanghai Typhoon Institute and Key Laboratory of Numerical Modeling for Tropical Cyclone of China Meteorological AdministrationShanghai 200030China Jiaxing Meteorological Bureau Jiaxing 314050China Fujian Key Laboratory of Severe Weather Fuzhou 350001China National Meteorological Information Center of China Meteorological Administration Beijing 100081China Bureau of Meteorology Melbourne 3008Australia

The rainfall forecast performance of the Tropical Cyclone(TC)version Model of Global and Regional Assimilation PrEdiction System(GRAPESTCM)of the China Meteorological Administration for landfalling Super Typhoon Lekima(2019)is studied by using the object-oriented verification method of contiguous rain area(CRA).The major error sources and possible reasons for the rainfall forecast uncertainties in different landfall stages(including near landfall and moving further inland)are *** show that different performance and errors of rainfall forecast exist in the different TC *** the near landfall stage the asymmetric rainfall distribution is hard to be simulated,which might be related to the too strong forecasted TC intensity and too weak vertical wind shear *** Lekima moves further inland,the rain pattern and volume errors gradually *** Equitable Threat Score of the 24 h forecasted rainfall over 100 mm declines quickly with the time-length over *** diagnostic analysis shows that there exists an interaction between the TC and the mid-latitude westerlies,but too weak frontogenesis is *** results of this research indicate that for the current numerical model,the forecast ability of persistent heavy rainfall is very limited,especially when the weakened landing TC moves further inland.

关键词： landing tropical cyclone rainfall forecast verification contiguous rain area Lekima

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油气管道安全仪表系统检验测试方法

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油气储运 2024年第8期43卷 944-951页

作者：刁宇李秋娟刘朝阳于子峰张冯银李东阳黄衫陶冶国家管网集团科学技术研究总院分公司国家石油天然气管网集团有限公司国家管网集团北方管道有限责任公司

【目的】智慧管网、无人值守站场的持续建设和快速发展对油气管道站场的安全性、可靠性等提出了更高的要求,安全仪表系统(Safety Instrumented System,SIS)是确保油气管道安全、可靠运行的重要环节。对SIS进行检验测试是确保安全仪表系... 详细信息

【目的】智慧管网、无人值守站场的持续建设和快速发展对油气管道站场的安全性、可靠性等提出了更高的要求,安全仪表系统(Safety Instrumented System,SIS)是确保油气管道安全、可靠运行的重要环节。对SIS进行检验测试是确保安全仪表系统满足设计安全完整性等级的关键,而当前中国尚无有效的技术手段支撑SIS开展检验测试。【方法】调研国内外SIS检验测试技术现状,梳理国内外SIS相关标准规范并结合现场工程实践,提出油气管道行业安全仪表系统检验测试方法,建立包括站场信息采集、故障模式识别、故障覆盖率评价、失效概率计算及安全完整性等级验证方面的SIS检验测试技术体系,明确了SIS检验测试的要求、内容及方法。【结果】通过开展现场SIS检验测试,能够有效识别SIS潜在的硬件故障、SIS错误配置与操作问题、SIS运行过程中存在的管理问题3大类功能安全风险项;提出检验测试覆盖率的简化计算方法,结合检验测试故障覆盖率、检验测试周期等参数可有效验证SIS的安全完整性等级是否满足设计要求,评估站场SIS能否持续提供足够的降险能力。【结论】油气管道现场SIS检验测试方法能够有效指导油气管道行业及其他行业开展SIS检验测试工作,可为提升油气站场SIS运行维护能力和管道企业的风险管控能力提供借鉴与支持。

关键词：安全仪表系统功能安全检验测试安全完整性

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An Embedded Consensus ADMM Distribution Algorithm Based on Outer Approximation for Improved Robust State Estimation of Networked

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Journal of Modern Power Systems and Clean Energy 2024年第4期12卷 1217-1226页

作者： zifeng Zhang yuntao Ju State Grid Information&Telecommunication Group Co. Ltd.Beijing BranchBejingChina School of Electrical and Control Engineering North China University of TechnologyBeijingChina

Networked microgrids(NMGs)are critical in theaccommodation of distributed renewable ***,theexisting centralized state estimation(SE)cannot meet the demandsof NMGs in distributed energy *** currentestimator is also not robust against bad *** study introducesthe concepts of relative error to construct an improvedrobust SE(IRSE)optimization model with mixed-integer nonlinearprogramming(MINLP)that overcomes the disadvantage ofinaccurate results derived from different measurements whenthe same tolerance range is considered in the robust SE(RSE).To improve the computation efficiency of the IRSE optimizationmodel,the number of binary variables is reduced based on theprojection statistics and normalized residual methods,which effectivelyavoid the problem of slow convergence or divergenceof the algorithm caused by too many integer ***,an embedded consensus alternating direction of multiplier method(ADMM)distribution algorithm based on outer approximation(OA)is proposed to solve the IRSE optimization *** algorithm can accurately detect bad data and obtain SE resultsthat communicate only the boundary coupling informationwith *** tests show that the proposed algorithmeffectively detects bad data,obtains more accurate SE results,and ensures the protection of private information in all microgrids.

关键词： Distributed optimization alternating direction of multiplier methods(ADMM) robust state estimation(RSE) mixed-integer nonlinear programming(MINLP) networked microgrid(NMG)

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浮选配位化学模型、溶液化学计算和扩展的DLVO理论在浮选机理研究中的应用进展

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有色金属工程 2024年第3期14卷 98-110页

作者：赵海平刘志伟刘敬智胡学平段文权高立强于梓丰贾炎阮仁满中关村科技园区西城园管理委员会博士后科研工作站北方矿业有限责任公司分站北京100053 北方矿业有限责任公司北京100053 中国科学院过程工程研究所绿色过程与工程重点实验室北京100190 中国科学院战略金属资源绿色循环利用国家工程研究中心北京100190

当把实验室的理论研究成果应用于生产实践时,经常发现两者间存在明显的差异,使得浮选研究,尤其是纯矿物研究的实用性大大降低,造成理论研究与实际应用结果存在差异的原因在于浮选过程的复杂性,研究中不仅要关注药剂在矿物表面吸附的化... 详细信息

当把实验室的理论研究成果应用于生产实践时,经常发现两者间存在明显的差异,使得浮选研究,尤其是纯矿物研究的实用性大大降低,造成理论研究与实际应用结果存在差异的原因在于浮选过程的复杂性,研究中不仅要关注药剂在矿物表面吸附的化学原理,还需要对浮选所处的化学环境(溶液条件、伴生矿物)进行综合的考虑分析。近年来,随着矿物浮选配位化学模型的提出和溶液化学理论的不断完善,给实现理论研究指导实际生产的目标提供了可能性。因此,收集总结了国内外关于矿物浮选配位化学模型、溶液化学计算和扩展的DLVO理论在矿物浮选机理研究中的应用实例,从理论内容、计算过程和应用实例等方面进行介绍并加以评论,以期对将来的浮选研究起到一定的参考作用。

关键词：浮选配位化学模型溶液化学扩展的DLVO理论浮选机理

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