Large and shallow lakes are widely influenced by multiple anthropogenic stressors,including eutrophication.Normally,diverse strategies of eutrophication management are needed to restore the lake ecosystems.Dianchi Lak...Large and shallow lakes are widely influenced by multiple anthropogenic stressors,including eutrophication.Normally,diverse strategies of eutrophication management are needed to restore the lake ecosystems.Dianchi Lake,a subtropical plateau lake in Yunnan Province,SW China,has long experienced the effects of eutrophication and cyanobacterial blooms.To mitigate the eutrophication of Dianchi Lake,various efforts have been implemented since 2000,including reducing nutrient inputs,reestablishing aquatic macrophytes in lakeside zones,manipulating fishes and so on.However,little is known about the changes in its ecosystem structure and function after long-term efforts of eutrophication management in the lake.Therefore,this study on such changes was conducted by comparing the field data-based Ecopath models between 2009 and 2019,a decade marked by a rapid implementation of eutrophication management policies.Results show that both top-down and bottom-up processes have influenced the ecosystem structure and function.First,over this decade,nutrient reduction significantly reduced phytoplankton biomass by 49.4%.Nutrient recycling and path length in food web began to decrease,as indicated by the decrease of Finn's cycling index and Finn's mean path length.Secondly,fishing management strategy has greatly changed the composition of fish assemblage,which was dominated by the small zooplantivorous fishes with ecological niche overlapping with shrimps.In general,the stability of the ecosystem has been decreasing,due to the dramatic decrease in zooplankton biomass(83.67%)and hence a collapse of the microbial loop in the food web.Therefore,we strongly advocate the persistent efforts to mitigate the risk of recurrent cyanobacteria blooms in Dianchi Lake,necessitating stricter regulation of nutrient levels and implementing effective fish population management techniques.展开更多
Algal blooms,the spread of algae on the surface of water bodies,have adverse effects not only on aquatic ecosystems but also on human life.The adverse effects of harmful algal blooms(HABs)necessitate a convenient solu...Algal blooms,the spread of algae on the surface of water bodies,have adverse effects not only on aquatic ecosystems but also on human life.The adverse effects of harmful algal blooms(HABs)necessitate a convenient solution for detection and monitoring.Unmanned aerial vehicles(UAVs)have recently emerged as a tool for algal bloom detection,efficiently providing on-demand images at high spatiotemporal resolutions.This study developed an image processing method for algal bloom area estimation from the aerial images(obtained from the internet)captured using UAVs.As a remote sensing method of HAB detection,analysis,and monitoring,a combination of histogram and texture analyses was used to efficiently estimate the area of HABs.Statistical features like entropy(using the Kullback-Leibler method)were emphasized with the aid of a gray-level co-occurrence matrix.The results showed that the orthogonal images demonstrated fewer errors,and the morphological filter best detected algal blooms in real time,with a precision of 80%.This study provided efficient image processing approaches using on-board UAVs for HAB monitoring.展开更多
计算机技术和通信技术的共同发展,使得数据呈现指数大爆炸式的增长。数据中蕴含的巨大价值是有目共睹的。但是对数据集的肆意收集与分析,使用户的隐私数据处在被泄露的风险中。为保护用户的敏感数据的同时实现对基数查询的有效响应,提...计算机技术和通信技术的共同发展,使得数据呈现指数大爆炸式的增长。数据中蕴含的巨大价值是有目共睹的。但是对数据集的肆意收集与分析,使用户的隐私数据处在被泄露的风险中。为保护用户的敏感数据的同时实现对基数查询的有效响应,提出一种基于差分隐私的隐私保护算法BFRRCE(Bloom Filter Random Response for Cardinality Estimation)。首先对用户的数据利用Bloom Filter数据结构进行数据预处理,然后利用本地差分隐私的扰动算法对数据进行扰动,达到保护用户敏感数据的目的。展开更多
Cyanobacteria blooms and their secondary hazards(cyanotoxins,taste and odor compounds)continue to harm the ecological environment of natural and semi-artificially regulated water bodies in the world,thus affecting the...Cyanobacteria blooms and their secondary hazards(cyanotoxins,taste and odor compounds)continue to harm the ecological environment of natural and semi-artificially regulated water bodies in the world,thus affecting the safety of water supply and aquatic product quality.The 8 th National Cyanobacteria Bloom Forum was successfully held on July 14-16,2023,in Tianjin,China.The forum established an academic exchange platform for nearly 300 water ecology experts,reservoir managers,and aquaculture technicians.展开更多
提出了一种基于双层Counter Bloom Filter的长流识别算法(algorithm based on double counter bloom filter for long flows identification,简称CCBF).该算法使用两层Counter Bloom Filter结构,将长流过滤和长流存在分开处理.分析了该...提出了一种基于双层Counter Bloom Filter的长流识别算法(algorithm based on double counter bloom filter for long flows identification,简称CCBF).该算法使用两层Counter Bloom Filter结构,将长流过滤和长流存在分开处理.分析了该算法的误判率,通过模拟数据分析了算法错误率和内存资源限制的关系,并在相同内存资源限制的条件下,将该算法与类似算法的准确性进行了比较.结果表明,在数据量较大的情况下,该算法具有比现有算法更小的平均错误率;对算法的时间效率分析表明,该算法可以达到1500kpps的处理速度.各项指标反映出,该算法可以应用于大规模主干网的长流监测.展开更多
基金Supported by the Yunnan-Kunming Major Science and Technology Project(No.202202AH210006)the Dianchi Lake Ecosystem Observation and Research Station of Yunnan Province Project(No.202305AM340008)+2 种基金the Yunnan-Kunming Liu Yongding Academician Workstation Funds(No.YSZJGZZ-2020018)the Yunnan Science and Technology Commission(Nos.202401AS070119,202103AC100001)the National Natural Science Foundation of China(No.52379081)。
文摘Large and shallow lakes are widely influenced by multiple anthropogenic stressors,including eutrophication.Normally,diverse strategies of eutrophication management are needed to restore the lake ecosystems.Dianchi Lake,a subtropical plateau lake in Yunnan Province,SW China,has long experienced the effects of eutrophication and cyanobacterial blooms.To mitigate the eutrophication of Dianchi Lake,various efforts have been implemented since 2000,including reducing nutrient inputs,reestablishing aquatic macrophytes in lakeside zones,manipulating fishes and so on.However,little is known about the changes in its ecosystem structure and function after long-term efforts of eutrophication management in the lake.Therefore,this study on such changes was conducted by comparing the field data-based Ecopath models between 2009 and 2019,a decade marked by a rapid implementation of eutrophication management policies.Results show that both top-down and bottom-up processes have influenced the ecosystem structure and function.First,over this decade,nutrient reduction significantly reduced phytoplankton biomass by 49.4%.Nutrient recycling and path length in food web began to decrease,as indicated by the decrease of Finn's cycling index and Finn's mean path length.Secondly,fishing management strategy has greatly changed the composition of fish assemblage,which was dominated by the small zooplantivorous fishes with ecological niche overlapping with shrimps.In general,the stability of the ecosystem has been decreasing,due to the dramatic decrease in zooplankton biomass(83.67%)and hence a collapse of the microbial loop in the food web.Therefore,we strongly advocate the persistent efforts to mitigate the risk of recurrent cyanobacteria blooms in Dianchi Lake,necessitating stricter regulation of nutrient levels and implementing effective fish population management techniques.
文摘Algal blooms,the spread of algae on the surface of water bodies,have adverse effects not only on aquatic ecosystems but also on human life.The adverse effects of harmful algal blooms(HABs)necessitate a convenient solution for detection and monitoring.Unmanned aerial vehicles(UAVs)have recently emerged as a tool for algal bloom detection,efficiently providing on-demand images at high spatiotemporal resolutions.This study developed an image processing method for algal bloom area estimation from the aerial images(obtained from the internet)captured using UAVs.As a remote sensing method of HAB detection,analysis,and monitoring,a combination of histogram and texture analyses was used to efficiently estimate the area of HABs.Statistical features like entropy(using the Kullback-Leibler method)were emphasized with the aid of a gray-level co-occurrence matrix.The results showed that the orthogonal images demonstrated fewer errors,and the morphological filter best detected algal blooms in real time,with a precision of 80%.This study provided efficient image processing approaches using on-board UAVs for HAB monitoring.
文摘计算机技术和通信技术的共同发展,使得数据呈现指数大爆炸式的增长。数据中蕴含的巨大价值是有目共睹的。但是对数据集的肆意收集与分析,使用户的隐私数据处在被泄露的风险中。为保护用户的敏感数据的同时实现对基数查询的有效响应,提出一种基于差分隐私的隐私保护算法BFRRCE(Bloom Filter Random Response for Cardinality Estimation)。首先对用户的数据利用Bloom Filter数据结构进行数据预处理,然后利用本地差分隐私的扰动算法对数据进行扰动,达到保护用户敏感数据的目的。
基金Supported by the National Natural Science Foundation of China(Nos.32172978,31772857)the Natural Science Foundation of Tianjin(No.22JCYBJC00430)。
文摘Cyanobacteria blooms and their secondary hazards(cyanotoxins,taste and odor compounds)continue to harm the ecological environment of natural and semi-artificially regulated water bodies in the world,thus affecting the safety of water supply and aquatic product quality.The 8 th National Cyanobacteria Bloom Forum was successfully held on July 14-16,2023,in Tianjin,China.The forum established an academic exchange platform for nearly 300 water ecology experts,reservoir managers,and aquaculture technicians.
文摘提出了一种基于双层Counter Bloom Filter的长流识别算法(algorithm based on double counter bloom filter for long flows identification,简称CCBF).该算法使用两层Counter Bloom Filter结构,将长流过滤和长流存在分开处理.分析了该算法的误判率,通过模拟数据分析了算法错误率和内存资源限制的关系,并在相同内存资源限制的条件下,将该算法与类似算法的准确性进行了比较.结果表明,在数据量较大的情况下,该算法具有比现有算法更小的平均错误率;对算法的时间效率分析表明,该算法可以达到1500kpps的处理速度.各项指标反映出,该算法可以应用于大规模主干网的长流监测.
