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基于改进YOLOv5的水下废弃物红外检测算法

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红外技术 2024年第9期46卷 994-1005页

作者：高永奇袁志祥安徽工业大学计算机科学与技术学院安徽马鞍山243032

针对水下废弃物红外目标检测中出现的检测目标边界细节模糊、图像质量低和存在各种不规则形状或损坏的覆盖物等问题,本文提出了一种基于YOLOv5的改进目标检测方法(EFDCD-YOLO)。在主干网络中选择InceptionNeXt网络,以增强模型的表达能... 详细信息

针对水下废弃物红外目标检测中出现的检测目标边界细节模糊、图像质量低和存在各种不规则形状或损坏的覆盖物等问题,本文提出了一种基于YOLOv5的改进目标检测方法(EFDCD-YOLO)。在主干网络中选择InceptionNeXt网络,以增强模型的表达能力和特征提取能力。其次,在特征融合层中通过加入EffectiveSE注意力机制,自适应地学习特征通道的重要性,并进行选择性加权。采用可变形卷积替代原模型中的C3模块,使模型能够更好地感知目标的形状和细节信息。此外,将CARAFE算子替代上采样模块,增强对细粒度特征的表现能力,避免信息丢失。在损失函数方面,采用Focal-EIOU损失函数,以提高模型对目标定位和边界框回归的准确性。最后,引入DyHead替换YOLOv5中的头部,通过动态感受野机制和多尺度的特征融合方式,提升模型的准确性。将改进后的EFDCDYOLO模型应用于水下废弃物红外目标检测,相比于YOLOv5模型,改进后的模型在准确率(P)、召回率(R)和平均精度(mAP)方面分别提升了21.4%、9.7%和13.6%。实验结果表明,EFDCD-YOLO能够有效地提升水下废弃物红外目标检测场景的性能,更好地满足水下废弃物红外目标检测的需求。

关键词：水下废弃物红外目标检测注意力机制可变形卷积动态感受野

基于改进SBAS-InSAR技术的西南山区铁路沿线地表形变监测方法研究

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铁道标准设计 2024年第8期68卷 58-64,85页

作者：高永琪胡亚中铁(广州)投资发展有限公司广州510335 西南交通大学地球科学与工程学院成都611756

合成孔径雷达干涉测量技术(Interferometric Synthetic Aperture Radar, InSAR)是一种新兴的对地观测手段,因其不受昼夜、云雨限制,被广泛应用于地表形变监测等领域。然而,受大气误差与失相干影响,InSAR技术仍然存在一些局限,尤其在植... 详细信息

合成孔径雷达干涉测量技术(Interferometric Synthetic Aperture Radar, InSAR)是一种新兴的对地观测手段,因其不受昼夜、云雨限制,被广泛应用于地表形变监测等领域。然而,受大气误差与失相干影响,InSAR技术仍然存在一些局限,尤其在植被茂密的西南山区,以SBAS-InSAR为代表的时间序列InSAR方法存在观测点不足的问题,难以开展山区变形监测。针对以上问题,考虑西南山区气候特征,设计改进的SBAS-InSAR时间序列处理方法,对干涉相位进行优化。丽香铁路是我国云南省境内一条连接丽江市与迪庆藏族自治州香格里拉的电气化铁路,是西部铁路网中滇藏铁路的重要组成部分。为保障丽香铁路安全稳定,同时验证上述方法的可用性,以丽香铁路段沿线的某段为研究区,利用星载SAR卫星存档影像数据对其周边地表开展历史形变探测,计算研究区近6.5年(2015年05月16日至2021年12月10日)的历史形变时间序列,并分析其影响范围、形变因素、变化规律等信息。最后将提出的改进后的SBAS-InSAR方法与常规InSAR方法比较,充分证明了所提出方法的优越性。

关键词：山区铁路地表形变监测 SBAS-InSAR 雷达差分干涉测量相位估计优化变形分析

The Relationship between Melt Season Sea Ice over the Bering Sea and Summer Precipitation over Mid-Latitude East Asia

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Advances in Atmospheric Sciences 2021年第6期38卷 918-930页

作者： Yurun TIAN yongqi gao Dong GUO Nansen-Zhu International Research Centre Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China Nansen Environmental and Remote Sensing Centre/Bjerknes Centre for Climate Research Bergen N-5006Norway Climate Change Research Centre Chinese Academy of SciencesBeijing100029China

Independent datasets consistently indicate a significant correlation between the sea ice variability in the Bering Sea during melt season and the summer rainfall variability in the Lake Baikal area and Northeastern *** this study,four sea ice datasets(HadISST1,HadISST2.2,ERA-Interim and NOAA/NSIDC)and two global precipitation datasets(CRU V4.01 and GPCP V2.3)are used to investigate co-variations between melt season(March−April−May−June,MAMJ)Bering Sea ice cover(BSIC)and summer(June−July−August,JJA)East Asian *** datasets demonstrate a significant correlation between the MAMJ BSIC and the JJA rainfall in Lake Baikal−Northeastern China(Baikal−NEC).Based on the reanalysis datasets and the numerical sensitivity experiments performed in this study using Community Atmospheric Model version 5(CAM5),a mechanism to understand how the MAMJ BSIC influences the JJA Baikal−NEC rainfall is *** MAMJ BSIC triggers a wave train and causes a positive sea level pressure(SLP)anomaly over the North Atlantic during *** high SLP anomaly,associated with an anti-cyclonic wind stress circulation anomaly,favors the appearance of sea surface temperature(SST)anomalies in a zonal dipole-pattern in the North Atlantic during *** dipole SST anomaly drives a zonally orientated wave train,which causes a high anomaly geopotential height at 500 hPa over the Sea of *** a result,the mean East Asian trough moves westward and a low geopotential height anomaly occurs over Baikal−*** prevailing regional low pressure anomaly together with enhanced moisture transport from the western North Pacific and convergence over Baikal−NEC,positively influences the increased rainfall in summer.

关键词： Bering Sea ice North Atlantic SST East Asian summer precipitation wave train

Stratospheric Precursor of Non-Uniform Variation in Early Spring Surface Temperature over Eurasia

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Journal of Meteorological Research 2017年第2期31卷 389-396页

作者： Fei LI Huijun WANG yongqi gao Nansen-Zhu International Research Centre Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Climate Change Research Center Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science & Technology Nanjing 210044 China Nansen Environmental and-Remote Sensing Centre and Bjerknes CentrejCor Climate Research Bergen N-5006 Norway

The stratospheric influences on the non-uniform variation in early spring（March–April,MA）surface temperature over Eurasia is investigated based on the ERA-Interim,NCEP-1,and NCEP-2 reanalysis data for the period1980–2016.A lead–lag correlation is found between preceding winter（December–February,DJF）stratospheric polar vortex displacements（SPVD）and the MA west–east seesaw pattern in surface temperature over *** analysis reveals that the East Asian jet stream may act as a bridge linking DJF SPVD and MA surface temperature over Eurasia.A positive change in SPVD is associated with a decelerated polar jet stream and an accelerated East Asian jet stream in the troposphere in *** East Asian jet stream signal can persist into *** a result,anomalous southerly/northerly winds prevail over western/eastern Eurasia,accounting for the west–east surface temperature seesaw over Eurasia.

关键词： stratospheric polar vortex displacement Eurasian surface temperature East Asian jet stream

The Response of the East Asian Summer Monsoon to Strong Tropical Volcanic Eruptions

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Advances in Atmospheric Sciences 2014年第6期31卷 1245-1255页

作者： CUI Xuedong gao yongqi SUN Jianqi Nansen-Zhu International Research Centre Institute of Atmospheric PhysicsChinese Academy of Sciences University of Chinese Academy of Sciences Nansen Environmental and Remote Sensing Center Bergen Bjerknes Center for Climate Research University of Bergen

A 600-year integration performed with the Bergen Climate Model and National Centers for Environmental Prediction/National Center for Atmospheric Research （NCEP/NCAR） reanalysis data were used to investigate the impact of strong tropical volcanic eruptions on the East Asian summer monsoon （EASM） and EASM *** the simulation and NCEP/NCAR reanalysis data show a weakening of the EASM in strong eruption *** model simulation suggests that North and South China experience droughts and the Yangtze-Huaihe River Valley experiences floods during eruption *** response to strong tropical volcanic eruptions,the meridional air temperature gradient in the upper troposphere is enhanced,which leads to a southward shift and an increase of the East Asian subtropical westerly jet stream （EASWJ）.At the same time,the land-sea thermal contrast between the Asian land mass and Northwest Pacific Ocean is *** southward shift and increase of the EASWJ and reduction of the land-sea thermal contrast all contribute to a weakening of the EASM and EASM rainfall anomaly.

关键词： East Asian summer monsoon volcanic eruption East Asian subtropical westerly jet stream land-sea thermal contrast

A Sensitivity Study of Arctic Ice-Ocean Heat Exchange to the Three-Equation Boundary Condition Parametrization in CICE6

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Advances in Atmospheric Sciences 2022年第9期39卷 1398-1416页

作者： Lei YU Jiping LIU yongqi gao Qi SHU Climate Changes Research Center Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Department of Atmospheric and Environmental Sciences University at AlbanyState University of New YorkAlbanyNew York 12222USA Nansen Environmental and Remote Sensing Center/Bjerknes Center for Climate Research Bergen N-5007Norway Nansen-Zhu International Research Centre Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China First Institute of Oceanography Ministry of Natural ResourcesQingdao 266061China

In this study,we perform a stand-alone sensitivity study using the Los Alamos Sea ice model version 6(CICE6)to investigate the model sensitivity to two Ice-Ocean(IO)boundary condition *** is the two-equation approach that treats the freezing temperature as a function of the ocean mixed layer(ML)salinity,using two equations to parametrize the IO heat *** approach uses the salinity of the IO interface to define the actual freezing temperature,so an equation describing the salt flux at the IO interface is added to the two-equation approach,forming the so-called three-equation *** focus on the impact of the three-equation boundary condition on the IO heat exchange and associated basal melt/growth of the sea ice in the Arctic *** with the two-equation simulation,our three-equation simulation shows a reduced oceanic turbulent heat flux,weakened basal melt,increased ice thickness,and reduced sea surface temperature(SST)in the *** impacts occur mainly at the ice edge regions and manifest themselves in ***,in August,we observed a downward turbulent heat flux from the ice to the ocean ML in two of our three-equation sensitivity runs with a constant heat transfer coefficient(0.006),which caused heat divergence and congelation at the ice ***,the influence of different combinations of heat/salt transfer coefficients and thermal conductivity in the three-equation approach on the model simulated results is *** results presented in this study can provide insight into sea ice model sensitivity to the three-equation IO boundary condition for coupling the CICE6 to climate models.

关键词： Arctic ice-ocean heat exchange three-equation boundary condition reduced oceanic turbulent heat flux CICE6

Precipitation Pattern of the Mid-Holocene Simulated by a High-Resolution Regional Climate Model

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Advances in Atmospheric Sciences 2014年第4期31卷 962-971页

作者： YU Entao WANG Tao gao yongqi XIANG Weiling Nansen-Zhu International Research Centre Institute of Atmospheric Physics Chinese Academy of Sciences Climate Change Research Center Chinese Academy of Sciences Nansen Environmental and Remote Sensing Center State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric Physics Chinese Academy of Sciences

Early proxy-based studies suggested that there potentially occurred a ＂southern drought/northern flood＂（SDNF） over East China in the mid-Holocene （from roughly 7000 to 5000 years before present）.In this study,we used both global and regional atmospheric circulation models to demonstrate that the SDNF-namely,the precipitation increases over North China and decreases over the the lower reaches of the Yangtze River Valley--could have taken place in the *** found that the SDNF in the mid-Holocene was likely caused by the lower SST in the *** lowered SST and the higher air temperature over China's Mainland increased the land-sea thermal contrast and,as a result,strengthened the East Asian summer monsoon and enhanced the precipitation over North China.

关键词： mid-Holocene East China southern drought/northern flood

Influence of Low-frequency Solar Forcing on the East Asian Winter Monsoon Based on HadCM3 and Observations

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Advances in Atmospheric Sciences 2018年第9期35卷 1205-1215页

作者： Jiapeng MIAO Tao WANG Huijun WANG yongqi gao Nansen-Zhu International Research Centez Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and TechnologyNanjing 210044China Key Laboratory of Meteorological Disastez Nanjing University of lnformation Science and Technology Nanjing 210044China Climate Change Research Centez Chinese Academy of Sciences Beijing 100029China Nansen Environmental and Remote Sensing Center/Bjerknes Centre for Climate Research Bergen 5006Norway University of Chinese Academy of Sciences Beijing 100049China

In this study, we investigate the influence of low-frequency solar forcing on the East Asian winter monsoon（EAWM）by analyzing a four-member ensemble of 600-year simulations performed with Had CM3（Hadley Centre Coupled Model,version 3）. We find that the EAWM is strengthened when total solar irradiance（TSI） increases on the multidecadal time scale. The model results indicate that positive TSI anomalies can result in the weakening of Atlantic meridional overturning circulation, causing negative sea surface temperature（SST） anomalies in the North Atlantic. Especially for the subtropical North Atlantic, the negative SST anomalies can excite an anomalous Rossby wave train that moves from the subtropical North Atlantic to the Greenland Sea and finally to Siberia. In this process, the positive sea-ice feedback over the Greenland Sea further enhances the Rossby wave. The wave train can reach the Siberian region, and strengthen the Siberian high. As a result, low-level East Asian winter circulation is strengthened and the surface air temperature in East Asia decreases. Overall,when solar forcing is stronger on the multidecadal time scale, the EAWM is typically stronger than normal. Finally, a similar linkage can be observed between the EAWM and solar forcing during the period 1850–1970.

关键词： solar forcing East Asian winter monsoon Atlantic sea surface temperature Rossby wave train

Diagnosing Ocean Tracer Transport from Sellafield and Dounreay by Equivalent Diffusion and Age

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Advances in Atmospheric Sciences 2008年第5期25卷 805-814页

作者： Steinar ORRE yongqi gao Helge DRANGE Eric DELEERSNIJDER Nansen Environmental and Remote Sensing Center Bergen Norway Bjerknes Centre for Climate Research Bergen Norway Nansen-Zhu International Research Centre Institute of Atmospheric Physics （ IAP） Chinese Academy of Sciences （ CAS） Beijing 100029 Geophysical Institute University of Bergen Bergen Norway Centre for Systems Engineering and Applied Mechanics （CESAME） Louvain School of Engineering Universite catholique de Louvain Louvain-la-Neuve Belgium

A simple approach for estimating the equivalent diffusion for diagnosing tracer transport is proposed. Two different expressions are derived; one is based directly on an analytical solution of the two-dimensional advection-diffusion equation, the other uses the variance of the tracer distribution. To illustrate some features of the equivalent diffusion and possible applications thereof, idealized releases of passive tracers from the nuclear fuel reprocessing plants at Sellafield in the Irish Sea and Dounreay on the northern coast of Scotland have been simulated with a regional isopycnic co-ordinate Ocean General Circulation Model. Both continuous and pulse releases are considered; the former being representative of the actual historical discharges from the reprocessing plants, the latter resembling an accidental scenario. Age tracers are included to calculate the mean time elapsed since the tracers left their source regions. It is found that in the Nordic Seas the age of tracers from Dounreay is approximately 2 years younger than the age from Sellafield. Although tracers from both sources eventually end up along the same transport routes, significant qualitative differences regarding the dispersion properties are found. It is argued that one single parameter, the equivalent horizontal diffusion, which is estimated to be in the range of 20 56 m^2 s^-1 from Sellafield and 170-485 m^2 s^-1 from Dounreay, determines these differences.

关键词： equivalent diffusion passive tracers age tracers sellafield dounreay