任务调度算法的研究一直是异构计算技术研究中的热点,充分挖掘异构处理平台的并行优势,可最大限度实现平台资源的高效利用。通过分析异构处理平台的执行特点,设计符合异构处理平台的任务调度策略,提出面向异构处理平台的最长路径列表调...任务调度算法的研究一直是异构计算技术研究中的热点,充分挖掘异构处理平台的并行优势,可最大限度实现平台资源的高效利用。通过分析异构处理平台的执行特点,设计符合异构处理平台的任务调度策略,提出面向异构处理平台的最长路径列表调度算法(Longest path list scheduling algorithm,LPLS)。算法在任务优先级阶段,基于最长路径列表计算优先级,最耗时路径上的任务被优先调度;在处理器选择阶段,遵循任务完成时间最小的原则,所选择的处理器可使下阶段任务的完成时间更短,异构平台整体处理时间更小。仿真实验结果表明,相比于经典的HEFT算法,LPLS算法是一种负载更加均衡的算法,具有调度长度更短、效率更高等优势。展开更多
One method for identifying noncoding regulatory regions of a genome is to quantify rates of divergence between related species, as functional sequence will generally diverge more slowly. Most approaches to identifying...One method for identifying noncoding regulatory regions of a genome is to quantify rates of divergence between related species, as functional sequence will generally diverge more slowly. Most approaches to identifying these conserved noncoding sequences （CNSs） based on alignment have had relatively large minimum sequence lengths （≥15 bp） compared with the average length of known transcription factor binding sites. To circumvent this constraint, STAG-CNS that can simultaneously integrate the data from the promoters of conserved orthologous genes in three or more species was developed. Using the data from up to six grass species made it possible to identify conserved sequences as short as 9 bp with false discovery rate ≤0.05. These CNSs exhibit greater overlap with open chromatin regions identified using DNase I hypersensitivity assays, and are enriched in the promoters of genes involved in transcriptional regulation. STAG-CNS was further employed to characterize loss of conserved noncoding sequences associated with retained duplicate genes from the ancient maize polyploidy. Genes with fewer retained CNSs show lower overall expression, although this bias is more apparent in samples of complex organ systems containing many cell types, suggesting that CNS loss may correspond to a reduced number of expression contexts rather than lower expression levels across the entire ancestral expression domain.展开更多
文摘任务调度算法的研究一直是异构计算技术研究中的热点,充分挖掘异构处理平台的并行优势,可最大限度实现平台资源的高效利用。通过分析异构处理平台的执行特点,设计符合异构处理平台的任务调度策略,提出面向异构处理平台的最长路径列表调度算法(Longest path list scheduling algorithm,LPLS)。算法在任务优先级阶段,基于最长路径列表计算优先级,最耗时路径上的任务被优先调度;在处理器选择阶段,遵循任务完成时间最小的原则,所选择的处理器可使下阶段任务的完成时间更短,异构平台整体处理时间更小。仿真实验结果表明,相比于经典的HEFT算法,LPLS算法是一种负载更加均衡的算法,具有调度长度更短、效率更高等优势。
文摘One method for identifying noncoding regulatory regions of a genome is to quantify rates of divergence between related species, as functional sequence will generally diverge more slowly. Most approaches to identifying these conserved noncoding sequences （CNSs） based on alignment have had relatively large minimum sequence lengths （≥15 bp） compared with the average length of known transcription factor binding sites. To circumvent this constraint, STAG-CNS that can simultaneously integrate the data from the promoters of conserved orthologous genes in three or more species was developed. Using the data from up to six grass species made it possible to identify conserved sequences as short as 9 bp with false discovery rate ≤0.05. These CNSs exhibit greater overlap with open chromatin regions identified using DNase I hypersensitivity assays, and are enriched in the promoters of genes involved in transcriptional regulation. STAG-CNS was further employed to characterize loss of conserved noncoding sequences associated with retained duplicate genes from the ancient maize polyploidy. Genes with fewer retained CNSs show lower overall expression, although this bias is more apparent in samples of complex organ systems containing many cell types, suggesting that CNS loss may correspond to a reduced number of expression contexts rather than lower expression levels across the entire ancestral expression domain.
