期刊文献+
共找到4篇文章
< 1 >
每页显示 20 50 100
Unraveling Temporal Shifts in Drivers and Ecosystem Services in a Large Lake Ecosystem
1
作者 Tibor Erős András Specziár 《Ecosystem Health and Sustainability》 CSCD 2024年第4期57-72,共16页
Freshwaters provide essential ecosystem services(ESS)to humanity.However,most studies on freshwater ESS focus on a few services and ignore temporal changes in driver–ESS relationships.Using graph-based visualization,... Freshwaters provide essential ecosystem services(ESS)to humanity.However,most studies on freshwater ESS focus on a few services and ignore temporal changes in driver–ESS relationships.Using graph-based visualization,we examine co-occurrence patterns among drivers and among ESS across characteristic sociopolitical eras in the history of the largest shallow lake in Central and Eastern Europe(Lake Balaton,Hungary).We also evaluate driver–ESS relationships to characterize whether there are distinct clusters in these relationships,which can help to better understand how the different types of drivers influence provisioning,regulating,and cultural ESS and basic ecological functions of the lake.The analyses revealed that Lake Balaton suffers from several alteration effects,which are frequently cited as top threatening drivers in the decline of the ecological integrity and ESS of lake ecosystems.Of these,eutrophication,the spread of invasive species,fishery,urbanization processes,and,recently,the effects of climate change were the most important.Despite these threats,the lake still maintains diverse ESS,which are in complex relationship with each other and their drivers.We highlight that major past environmental changes substantially influence present and forecasted future patterns of driver–ESS relationships.Based on these results,we discuss the possibilities of management to ensure the sustainability of ESS Lake Balaton provides to society.Overall,this study underscores the complex influence of various drivers on freshwater ESS and emphasizes the importance of understanding temporal changes in human-modified lakes,considering societal,ecological,and economic factors comprehensively. 展开更多
关键词 Lake Balaton ecosystem services co occurrence patterns temporal shifts graph based visualization EUTROPHICATION DRIVERS driver ess relationships
原文传递
基于改进TSM的船舶驾驶员行为识别方法
2
作者 陈晨 魏月楠 +2 位作者 马枫 胡松涛 王腾飞 《交通信息与安全》 北大核心 2025年第1期120-129,140,共11页
船舶驾驶员不规范操作是诱发水上交通事故重要因素,设计1种实时船舶驾驶员行为检测方法意义重大。相比汽车驾驶、安防监控等,船舶驾驶舱环境更为复杂,存在无法兼顾多个船员、效率低下和准确率不高等问题。针对这种情况,研究了1种多目标... 船舶驾驶员不规范操作是诱发水上交通事故重要因素,设计1种实时船舶驾驶员行为检测方法意义重大。相比汽车驾驶、安防监控等,船舶驾驶舱环境更为复杂,存在无法兼顾多个船员、效率低下和准确率不高等问题。针对这种情况,研究了1种多目标跟踪和行为识别相结合的“两步式”多人行为识别方法。利用YoloV7与ByteTracker建立多目标跟踪器,形成单人的连续特征图。在单目标行为识别算法时间偏移模块(temporal shift module,TSM)的基础上,借助超采样、跨帧拼接等手段处理连续特征图,同时通过EfficientNet-B3与坐标注意力(coordinate attention,CA)模块输出高准确率的识别结果。研究建立了船舶驾驶舱行为数据集“SC-Action”,数据来自不同的船舶驾驶舱监控录像,包含常规行为以及违规行为共计2000例行为样本。在该数据集上对本文提出的模型进行迁移学习和消融实验,实验结果表明:提出的方法可实现3名驾驶员24帧/s的实时行为识别,识别速度和准确率均优于主流算法。在针对单人行为识别的测试中,方法在应用图像增强模块之后,相比基准TSM模型准确率提升了1.3%;结合注意力机制后,准确率进一步提升1.78%,达到了82.1%,而运算量仅增加0.1%。在多目标测试中,方法的实际推理速度和效果,也超越了该领域的主流方法如SlowFast,验证了其有效性。 展开更多
关键词 航行安全 行为识别 目标跟踪 注意力机制 temporal shift module
在线阅读 下载PDF
The phase shift analysis of the colliding dissipative KdV solitons
3
作者 Wedad Albalawi S.A.El-Tantawy Sadah A.Alkhateeb 《Journal of Ocean Engineering and Science》 SCIE 2022年第6期521-527,共7页
In this work,the head-on collisions of the non-stationary dissipative soliton in ultracold neutral plasmas(UNPs)are investigated.The extended Poincare-Lighthill-Kuo(PLK)approach is adopted for reducing the fluid equat... In this work,the head-on collisions of the non-stationary dissipative soliton in ultracold neutral plasmas(UNPs)are investigated.The extended Poincare-Lighthill-Kuo(PLK)approach is adopted for reducing the fluid equations of the UNPs to two-counterpropagating damped Korteweg-de Vries(dKdV)equations.The dKdV equation is not an integrable Hamiltonian system,i.e.,does not have an exact solution.Thus,one of the main goal of this paper is to find a new general approximate analytical solution to the dKdV equation for investigating the mechanism of the propagation and interaction of the non-stationary dissipative solitons.The residual error is estimated for checking the accuracy of the new obtained solution.The approximate analytical soliton solutions are adopted for deriving the temporal phase shifts after the collision.The impact of physical parameters on the nonstationary dissipative soliton profile and the temporal phase shifts is discussed.The obtained results will contribute to understand the mechanism of propagation and interaction of many nonlinear phenomena in different nonlinear mediums such as ocean,sea,optical fiber,plasma physics,etc. 展开更多
关键词 Dissipative soliton collisions Damped Korteweg-de Vries equation The extended Poincare-Lighthill-Kuo method The temporal phase shifts
原文传递
Plant-associated fungal communities in the light of meta’omics 被引量:8
4
作者 Derek Peršoh 《Fungal Diversity》 SCIE 2015年第6期1-25,共25页
Approaches for the cultivation-independent analysis of microbial communities are summarized as meta’omics,which predominantly includes metagenomic,-transcriptomic,-proteomic and-metabolomic studies.These have shown t... Approaches for the cultivation-independent analysis of microbial communities are summarized as meta’omics,which predominantly includes metagenomic,-transcriptomic,-proteomic and-metabolomic studies.These have shown that endophytic,root-associated and soil fungal communities are strongly shaped by associated plant species.The impact of plant identity on the composition of its litterssociated fungal community remains to be disentangled from the impact of litter chemistry.The composition of the plant community also shapes the fungal community.Most strikingly,adjacent plant species may share mycorrhizal symbionts even if the plants usually have different types of mycorrhizal fungi associated with them(ectomycorrhizal,ericoid and arbuscular mycorrhizal fungi).Environmental parameters weakly explain fungal community composition globally,and their effect is inconsistent at local and regional scales.Decrease in similarity among communities with increasing distance(i.e.distance decay)has been reported from local to global scales.This pattern is only exceptionally caused by spatial dispersal limitation of fungal propagules,but mostly due to the inability of the fungi to establish at the particular locality(i.e.environmental filtering or competitive exclusion).Fungal communities usually undergo pronounced seasonal changes and also differ between consecutive years.This indicates that development of the communities is usually not solely cyclic.Meta’omic studies challenge the classical view of plant litter decomposition.They show that mycorrhizal and(previously)endophytic fungi may be involved in plant litter decomposition and only partly support the idea of a succession from an Ascomycota to a Basidiomycota-dominated community.Furthermore,vertical separation of saprotrophic and mycorrhizal species in soil and sequential degradation from easily accessible to‘recalcitrant’plant compounds,such as lignin,can probably not be generalized.The current models of litter decomposition may therefore have to be eventually refined for certain ecosystems and environmental conditions.To gain deeper insights into fungal ecology,a meta’omic study design is outlined which focuses on environmental processes,because fungal communities are usually taxonomically diverse,but functionally redundant.This approach would initially identify dynamics of chemical shifts in the host and/or substrate by metametabolomics.Detected shifts would be subsequently linked to microbial activity by correlation with metatranscriptomic and/or metaproteomic data.A holistic trait-based approach might finally identify factors shaping taxonomic composition in communities against the dynamics of the environmental process(es)they are involved in. 展开更多
关键词 Meta’omics Metaomics Fungal community Metagenomics METAPROTEOMICS METATRANSCRIPTOMICS Metametabolomics Phyllosphere fungi Endophytic fungi Litter decomposition Decomposer fungi Root-associated fungi Arbuscular mycorrhiza ECTOMYCORRHIZA Ericoid mycorrhiza Soil fungi Functional diversity Environmental processes Distance decay Environmental filtering Saisonality temporal shift Fungal traits
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部