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A digital twins enabled underwater intelligent internet vehicle path planning system via reinforcement learning and edge computing

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Digital Communications and Networks 2024年第2期10卷 282-291页

作者： Jiachen Yang Meng Xi Jiabao Wen Yang Li Houbing Herbert Song School of Electrical and Information Engineering Tianjin UniversityTianjin300072China Security and Optimization for Networked globe Laboratory(SONG Lab) Embry-Riddle Aeronautical UniversityDaytona BeachFL32114USA

The Autonomous Underwater Glider(AUG)is a kind of prevailing underwater intelligent internet vehicle and occupies a dominant position in industrial applications,in which path planning is an essential problem.Due to the complexity and variability of the ocean,accurate environment modeling and flexible path planning algorithms are pivotal challenges.The traditional models mainly utilize mathematical functions,which are not complete and reliable.Most existing path planning algorithms depend on the environment and lack flexibility.To overcome these challenges,we propose a path planning system for underwater intelligent internet vehicles.It applies digital twins and sensor data to map the real ocean environment to a virtual digital space,which provides a comprehensive and reliable environment for path simulation.We design a value-based reinforcement learning path planning algorithm and explore the optimal network structure parameters.The path simulation is controlled by a closed-loop model integrated into the terminal vehicle through edge computing.The integration of state input enriches the learning of neural networks and helps to improve generalization and flexibility.The task-related reward function promotes the rapid convergence of the training.The experimental results prove that our reinforcement learning based path planning algorithm has great flexibility and can effectively adapt to a variety of different ocean conditions.

关键词： Digital twins Reinforcement learning Edge computing Underwater intelligent internet vehicle Path planning

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A neural branch-and-price for truck scheduling in cross-docks

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Science China Mathematics 2024年第6期67卷 1341-1358页

作者： Rahimeh Neamatian Monemi Shahin Gelareh Nelson Maculan Wei-Kun Chen Sharkey Predictim globe Villeneuve d’Ascq59650France Département R&T IUT de BéthuneUniversitéd’ArtoisBéthuneF-62000France Federal University of Rio de Janeiro COPPE-PESCRio de JaneiroRJ 21941-972Brazil School of Mathematics and Statistics Beijing Institute of TechnologyBeijing100081China

In this paper,we address the complex problem of dock-door assignment and truck scheduling within cross-docking operations.This is a problem that requires frequent resolution throughout the operational day,as disruptions often invalidate the optimal plan.Given the problem's highly combinatorial nature,finding an optimal solution demands significant computational time and resources.However,the distribution of data across problem instances over a lengthy planning horizon remains consistently stable,with minimal concern regarding distribution shift.These factors collectively establish the problem as an ideal candidate for a learn-to-optimize solution strategy.We propose a Dantzig-Wolfe reformulation,solving it via both a conventional branch-and-price approach and a neural branch-and-price approach,the latter of which employs imitation learning.Additionally,we introduce some classes of valid inequalities to enhance and refine the pricing problem through a branch-and-cut scheme.Our computational experiments demonstrate that this methodology is not only feasible but also presents a viable alternative to the traditional branch-and-price algorithms typically utilized for such challenges.

关键词： cross-docking MILP modeling Dantzig-Wolfe decomposition graph convolutional network

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Will the globe Encounter the Warmest Winter after the Hottest Summer in 2023?

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Advances in Atmospheric Sciences 2024年第4期41卷 581-586页

作者： Fei ZHENG Shuai HU Jiehua MA Lin WANG Kexin LI Bo WU Qing BAO Jingbei PENG Chaofan LI Haifeng ZONG Yao YAO Baoqiang TIAN Hong CHEN Xianmei LANG Fangxing FAN Xiao DONG Yanling ZHAN Tao ZHU Tianjun ZHOU Jiang ZHU International Center for Climate and Environment Science(ICCES) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics(LASG) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Nansen-Zhu International Research Centre(NZC) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Center for Monsoon System Research(CMSR) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China CAS Key Lab of Regional Climate-Environment for Temperate East Asia(RCE-TEA) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China

In the boreal summer and autumn of 2023,the globe experienced an extremely hot period across both oceans and continents.The consecutive record-breaking mean surface temperature has caused many to speculate upon how the global temperature will evolve in the coming 2023/24 boreal winter.In this report,as shown in the multi-model ensemble mean(MME)prediction released by the institute of Atmospheric Physics at the Chinese Academy of Sciences,a medium-to-strong eastern Pacific El Niño event will reach its mature phase in the following 2−3 months,which tends to excite an anomalous anticyclone over the western North Pacific and the Pacific-North American teleconnection,thus serving to modulate the winter climate in East Asia and North America.Despite some uncertainty due to unpredictable internal atmospheric variability,the global mean surface temperature(GMST)in the 2023/24 winter will likely be the warmest in recorded history as a consequence of both the El Niño event and the long-term global warming trend.Specifically,the middle and low latitudes of Eurasia are expected to experience an anomalously warm winter,and the surface air temperature anomaly in China will likely exceed 2.4 standard deviations above climatology and subsequently be recorded as the warmest winter since 1991.Moreover,the necessary early warnings are still reliable in the timely updated mediumterm numerical weather forecasts and sub-seasonal-to-seasonal prediction.

关键词： winter climate El Niño seasonal forecast GMST

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DNA metabarcoding reveals seasonal changes in diet composition across four arthropod-eating lizard species(Phrynosomatidae:Sceloporus)

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Integrative Zoology 2024年第3期19卷 480-495页

作者： Mauricio HERNÁNDEZ Stephanie HEREIRA-PACHECO Antton ALBERDI Aníbal H.DÍAZ DE LA VEGA-PÉREZ Arturo ESTRADA-TORRES Sergio ANCONA Yendi E.NAVARRO-NOYA Doctorado en Ciencias Biológicas Centro Tlaxcala de Biología de la ConductaUniversidad Autónoma de TlaxcalaTlaxcalaMexico Estación Científica La Malinche Centro Tlaxcala de Biología de la ConductaUniversidad Autónoma de TlaxcalaTlaxcalaMexico Center for Evolutionary Hologenomics The Globe InstituteUniversity of CopenhagenCopenhagenDenmark Consejo Nacional de Ciencia y Tecnología-Centro Tlaxcala de Biología de la Conducta Universidad Autónoma de TlaxcalaTlaxcalaMexico Departamento de Ecología Evolutiva Instituto de EcologíaUniversidad Nacional Autónoma de MéxicoMexico CityMexico Laboratorio de Interacciones Bióticas Centro de Investigación en Ciencias BiológicasUniversidad Autónoma de TlaxcalaSan Felipe IxtacuixtlaTlaxcalaMexico

Diet composition and its ecological drivers are rarely investigated in coexisting closely related species.We used a molecular approach to characterize the seasonal variation in diet composition in four spiny lizard species inhabiting a mountainous ecosystem.DNA metabarcoding revealed that the lizards Sceloporus aeneus,S.bicanthalis,S.grammicus,and S.spinosus mostly consumed arthropods of the orders Hemiptera,Araneae,Hymenoptera,and Coleoptera.The terrestrial lizards S.aeneus and S.bicanthalis mostly predated ants and spiders,whereas the arboreal–saxicolous S.grammicus and saxicolous S.spinosus largely consumed grasshoppers and leafhoppers.The taxonomic and phylogenetic diversity of the prey was higher during the dry season than the rainy season,likely because reduced prey availability in the dry season forced lizards to diversify their diets to meet their nutritional demands.Dietary and phylogenetic composition varied seasonally depending on the species,but only dietary composition varied with altitude.Seasonal dietary turnover was greater in S.spinosus than in S.bicanthalis,suggesting site-specific seasonal variability in prey availability;no other differences among species were observed.S.bicanthalis,which lives at the highest altitude in our study site,displayed interseasonal variation in diet breadth.Dietary differences were correlated with the species’feeding strategies and elevational distribution,which likely contributed to the coexistence of these lizard species in the studied geographic area and beyond.

关键词： arthropod-eating lizards diet breadth environmental barcoding mountainous ecosystem seasonal dietary shifts

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Impacts of permafrost degradation on streamflow in the northern Himalayas

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Science China Earth Sciences 2024年第6期67卷 1990-2000页

作者： Linfeng FAN Fang JI Xingxing KUANG Zhilin GUO Rui ZHANG Chunmiao ZHENG State Key Laboratory of Mountain Hazards and Engineering Resilience Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610299China Yangtze institute for Conservation and Development Hohai UniversityNanjing 210024China School of Environmental Science and Engineering Southern University of Science and TechnologyShenzhen 518055China Eastern institute for Advanced Study Ningbo 315200China

The Himalayan water tower provides crucial water resources for Asia.Permafrost degradation is deemed to exert important impacts on streamflow in the Himalayan rivers.Yet,the magnitudes of such impacts remain poorly quantified.Here,we established a robust hydrological model that incorporated active layer deepening and ground ice melt for the drainage basin of the largest river in the northern Himalayas-the Yarlung Zangbo River(YZR).We estimated that permafrost degradation led to~0.65 km^(3)/yr decrease in surface runoff and~0.35 km^(3)/yr increase in baseflow and ground ice melt contributed~0.25% to the annual streamflow in the YZR for the period 2001-2022.The“fill-and-spill”mechanism helps explain the seeming contradiction of observed increasing versus decreasing baseflow in different permafrost regions worldwide.We propose that the dilution of riverine dissolved organic carbon(DOC)concentrations by baseflow may lead to the riverine DOC hysteresis patterns.This study not only lays solid scientific basis for water resources management in the Himalayas,but also yields new insights into how to interpret measured river discharge and nutrient flux in permafrost regions over the globe.

关键词： Permafrost degradation Hydrology Streamflow Surface runoff Groundwater Himalayas

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2023: Weather and Climate Extremes Hitting the globe with Emerging Features

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Advances in Atmospheric Sciences 2024年第6期41卷 1001-1016页

作者： Wenxia ZHANG Robin CLARK Tianjun ZHOU Laurent LI Chao LI Juan RIVERA Lixia ZHANG Kexin GUI Tingyu ZHANG Lan LI Rongyun PAN Yongjun CHEN Shijie TANG Xin HUANG Shuai HU State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Met Office Hadley Centre Exeter EX13PBUK University of Chinese Academy of Sciences Beijing 100049China Laboratoire de Météorologie Dynamique CNRSSorbonne UniversitéEcole Normale SupérieureEcole PolytechniqueParis 75230France Max Planck institute for Meteorology Hamburg 20146Germany Instituto Argentino de Nivología Glaciología Y Ciencias Ambientales(IANIGLA)CCT CONICETMendoza CP 5500Argentina Shanghai Typhoon institute China Meteorological AdministrationShanghai 200030China Asia-Pacific Typhoon Collaborative Research Center Shanghai 201306China

Globally,2023 was the warmest observed year on record since at least 1850 and,according to proxy evidence,possibly of the past 100000 years.As in recent years,the record warmth has again been accompanied with yet more extreme weather and climate events throughout the world.Here,we provide an overview of those of 2023,with details and key background causes to help build upon our understanding of the roles of internal climate variability and anthropogenic climate change.We also highlight emerging features associated with some of these extreme events.Hot extremes are occurring earlier in the year,and increasingly simultaneously in differing parts of the world(e.g.,the concurrent hot extremes in the Northern Hemisphere in July 2023).Intense cyclones are exacerbating precipitation extremes(e.g.,the North China flooding in July and the Libya flooding in September).Droughts in some regions(e.g.,California and the Horn of Africa)have transitioned into flood conditions.Climate extremes also show increasing interactions with ecosystems via wildfires(e.g.,those in Hawaii in August and in Canada from spring to autumn 2023)and sandstorms(e.g.,those in Mongolia in April 2023).Finally,we also consider the challenges to research that these emerging characteristics present for the strategy and practice of adaptation.

关键词： weather and climate extremes temperature extremes extreme precipitation drought wildfires

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Changes in global land surface frozen ground and freeze-thaw processes during 1950-2020 based on ERA5-Land data

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Advances in Climate Change Research 2024年第2期15卷 265-274页

作者： Yong YANG Ren-Sheng CHEN Yong-Jian DING Hong-Yuan LI Zhang-Wen LIU Qilian Alpine Ecology and Hydrology Research Station Key Laboratory of Ecological Safety and Sustainable Development in Arid LandsNorthwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 73000China State Key Laboratory of Cryospheric Sciences Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 73000China Shandong Provincial Key Laboratory of Water and Soil Conservation and Environmental Protection College of Resources and EnvironmentLinyi UniversityLinyi 276000China

Frozen ground(FG)plays an important role in global and regional climates and environments through changes in land freeze-thaw processes,which have been conducted mainly in different regions.However,the changes in land surface freeze-thaw processes under climate change on a global scale are still unclear.Based on ERA5-Land hourly land skin temperature data,this study evaluated changes in the global FG area,global land surface first freeze date(FFD),last freeze date(LFD)and frost-free period(FFP)from 1950 to 2020.The results show that the current FG areas(1991-2020 mean)in the Northern Hemisphere(NH),Southern Hemisphere(SH),and globe are 68.50×10^(6),9.03×10^(6),and 77.53×10^(6)km^(2),which account for 72.4%,26.8%,and 60.4%of the exposed land(excluding glaciers,ice sheets,and water bodies)in the NH,SH and the globe,respectively;further,relative to 1951-1980,the FG area decreased by 1.9%,8.8%,and 2.8%,respectively.Seasonally FG at lower latitudes degrades to intermittently FG,and intermittently FG degrades to non-frozen ground,which caused the global FG boundary to retreat to higher latitudes from 1950 to 2020.The annual FG areas in the NH,SH,and globe all show significant decreasing trends(p<0.05)from 1950 to 2020 at-0.32×10^(6),-0.22×10^(6),and-0.54×10^(6)km^(2)per decade,respectively.The FFP prolongation in the NH is mainly influenced by LFD advance,while in the SH it is mainly controlled by FFD delay.The prolongation trend of FFP in the NH(1.34 d per decade)is larger than that in the SH(1.15 d per decade).

关键词： Frozen ground Freeze-thaw processes Frost-free period First freeze date Global warming

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Exploring the Reasons for Selfie-Taking and Selfie-Posting on Social Media with Its Effect on Psychological and Social Lives:A Study among Indian Youths

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International Journal of Mental Health Promotion 2024年第5期26卷 389-398页

作者： Divya P.Vijayan Tokani Ghuhato Eslavath Rajkumar Allen Joshua George Romate John John Abraham Department of Psychology Central University of KarnatakaKalaburagi585367India Department of Liberal Arts Indian Institute of Technology BhilaiChhattisgarh491002India Liberal Arts&Sciences Indian Institute of Management RanchiJharkhand834001India Department of Family Medicine/Geriatrics St.John’s National Academy of Health SciencesBangalore560034India

‘Selfie’taking was introduced to the common people by smartphones and has become a common practice across the globe in no time.With technological advancement and the popularity of smartphones,selfie-taking has grown rapidly within a short time.In light of the new trend set by the generation,this study aimed to explore reasons for selfie-taking and selfie-posting on social media and their effects on the social and psychological lives of young adults.A purposive sampling method was adopted to select 20 Indian citizens,between 18 and 24 years.The data were collected through semi-structured interviews and analysed using thematic analysis.Selfie-taking and posting on social media give positive feelings,and it acts as a mood modifier dependent mostly on the favourability and feedback about the post which in turn affects emotions and self-satisfaction.

关键词： Selfie social media social networking sites obsessive selfie-taking Indian youth

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Effect of weight-adjusted antimicrobial antibiotic prophylaxis on postoperative dosage and surgical site infection incidence in total joint arthroplasty

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World Journal of Orthopedics 2024年第4期15卷 318-320页

作者： Ashim Gupta Vijay Kumar Jain Department of Orthopaedics and Regenerative Medicine Future BiologicsLawrencevilleGA 30043United States Department of Orthopaedics South Texas Orthopaedic Research Institute(STORI Inc.)LaredoTX 78045United States Department of Regenerative Medicine BioIntegrateLawrencevilleGA 30043United States Department of Orthopaedics and Regenerative Medicine Regenerative OrthopaedicsNoida 201301India Department of Orthopaedics Atal Bihari Vajpayee Institute of Medical SciencesDr Ram Manohar Lohia HospitalNew Delhi 110001India

Surgical site infections(SSI)following total joint arthroplasty pose a significant concern for both providers and patients across the globe.Currently,administration of antimicrobial antibiotic prophylaxis is used throughout the world to reduce the incidence of SSI.However,the correct dosage and frequency of administration remains debatable.In this editorial,we emphasized the determination of the effect of administration of weight-adjusted antimicrobial antibiotic prophylaxis regime on the incidence of SSI and postoperative dosage reduction compared to the conventionally used regime during total joint arthroplasty.The results demonstrated similar efficacy between both regimes with respect to the incidence of SSI.In addition,weight-adjustment led to reduced postoperative dosage and has the potential to reduce chances of achieving lower therapeutic concentration,drug resistance,drug toxicity,and costs.

关键词： Antibiotics Antimicrobial prophylaxis Weight-adjusted Surgical site infections Total joint arthroplasty Knee arthroplasty Hip arthroplasty

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The Forecast Skills and Predictability Sources of Marine Heatwaves in the NUIST-CFS1.0 Hindcasts

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Advances in Atmospheric Sciences 2024年第8期41卷 1589-1600页

作者： Jing MA Haiming XU Changming DONG Jing-Jia LUO Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters/KLME/ILCEC/institute of Climate and Application Research (ICAR) Nanjing University of Information Science and Technology

Using monthly observations and ensemble hindcasts of the Nanjing University of Information Science and Technology Climate Forecast System(NUIST-CFS1.0) for the period 1983–2020, this study investigates the forecast skill of marine heatwaves(MHWs) over the globe and the predictability sources of the MHWs over the tropical oceans. The MHW forecasts are demonstrated to be skillful on seasonal-annual time scales, particularly in tropical oceans. The forecast skill of the MHWs over the tropical Pacific Ocean(TPO) remains high at lead times of 1–24 months, indicating a forecast better than random chance for up to two years. The forecast skill is subject to the spring predictability barrier of El Ni?o-Southern Oscillation(ENSO). The forecast skills for the MHWs over the tropical Indian Ocean(TIO), tropical Atlantic Ocean(TAO), and tropical Northwest Pacific(NWP) are lower than that in the TPO. A reliable forecast at lead times of up to two years is shown over the TIO, while a shorter reliable forecast window(less than 17 months) occurs for the TAO and NWP.Additionally, the forecast skills for the TIO, TAO, and NWP are seasonally dependent. Higher skills for the TIO and TAO appear in boreal spring, while a greater skill for the NWP emerges in late summer-early autumn. Further analyses suggest that ENSO serves as a critical source of predictability for MHWs over the TIO and TAO in spring and MHWs over the NWP in summer.

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