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CLEAN:Frequent Pattern-Based Trajectory Compression and Computation on Road Networks 被引量:1
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作者 Peng Zhao Qinpei Zhao +3 位作者 Chenxi Zhang gong su Qi Zhang Weixiong Rao 《China Communications》 SCIE CSCD 2020年第5期119-136,共18页
The volume of trajectory data has become tremendously huge in recent years. How to effectively and efficiently maintain and compute such trajectory data has become a challenging task. In this paper, we propose a traje... The volume of trajectory data has become tremendously huge in recent years. How to effectively and efficiently maintain and compute such trajectory data has become a challenging task. In this paper, we propose a trajectory spatial and temporal compression framework, namely CLEAN. The key of spatial compression is to mine meaningful trajectory frequent patterns on road network. By treating the mined patterns as dictionary items, the long trajectories have the chance to be encoded by shorter paths, thus leading to smaller space cost. And an error-bounded temporal compression is carefully designed on top of the identified spatial patterns for much low space cost. Meanwhile, the patterns are also utilized to improve the performance of two trajectory applications, range query and clustering, without decompression overhead. Extensive experiments on real trajectory datasets validate that CLEAN significantly outperforms existing state-of-art approaches in terms of spatial-temporal compression and trajectory applications. 展开更多
关键词 trajectory compression pattern mining spatial-temporal compressions range query CLUSTERING
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基于COⅠ基因的储粮象甲害虫的分子检测技术研究
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作者 吴芳 龚殊 严晓平 《粮食与饲料工业》 CAS 2021年第4期15-20,共6页
米象、玉米象和谷象是粮食与饲料储藏期间容易发生的3种常见象甲类害虫,仅从形态上进行鉴别存在一定的缺陷,建立快速准确鉴定3种常见储粮象甲类害虫的分子方法,可以弥补形态鉴别存在的不足。以3种常见储粮象甲害虫共38个地理来源样本为... 米象、玉米象和谷象是粮食与饲料储藏期间容易发生的3种常见象甲类害虫,仅从形态上进行鉴别存在一定的缺陷,建立快速准确鉴定3种常见储粮象甲类害虫的分子方法,可以弥补形态鉴别存在的不足。以3种常见储粮象甲害虫共38个地理来源样本为研究对象,采用DNA条形码技术,通过对线粒体细胞色素C氧化酶亚基(COⅠ)基因的特定区段(约426 bp)的测序和比对,以MEGA软件的K2-P双参数模型计算种内及种间遗传距离,以邻接法(NJ)构建系统发育树。碱基含量组成符合昆虫线粒体基因碱基组成的基本特征;种内遗传距离为0.000~0.007,平均为0.0034;种间遗传距离为0.163~0.207,平均为0.1932。邻接法系统发育树显示,聚类分析与形态学鉴定结果一致,3种储粮象甲各自聚为同一小支,且分支自展值均为100%,置信度高(98%),该段序列能有效区分3种储粮象甲。说明DNA条形码可以作为3种储粮象甲种间鉴别的分子方法。 展开更多
关键词 象甲类储粮害虫 DNA条形码 线粒体COⅠ基因 物种鉴定
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