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
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
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。
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.
