为解决第三代音视频编码标准(audio video coding standard 3,AVS3)帧内预测的耗时问题,提出一种基于最小编码单元(coding unit,CU)代价的帧内预测并行算法。首先,将图像划分为最小CU。然后,利用原始像素作为参考,并行计算所有最小CU的...为解决第三代音视频编码标准(audio video coding standard 3,AVS3)帧内预测的耗时问题,提出一种基于最小编码单元(coding unit,CU)代价的帧内预测并行算法。首先,将图像划分为最小CU。然后,利用原始像素作为参考,并行计算所有最小CU的帧内模式代价。最后,用代价组合的方式快速计算出其他CU的帧内模式优先级,选择最优的15个模式进入粗略模式决策(rough mode decision,RMD)阶段。此外,为减少方法引入的误差,提出了3种优化策略。在预测前对原始像素进行预处理,使其更贴合重构像素;修改帧内预测的代价函数,以更准确地估计每种模式的优先级;大尺寸CU使用顶层的CU代价作为参考,减少CU组合累积的误差。实验结果表明,在码率仅下降0.35%的情况下,整体编码的计算时间减少了27%,有效地减少了帧内预测的耗时并保证了编码质量。展开更多
提出一种基于样本迭代的远距离帧内预测方法,通过迭代预测引入非相邻的像素来作为参考样本,提供更多的空间信息,以改进帧内预测性能。同时,考虑到编码块的纹理复杂度和预测方向之间的联系,根据当前块的纹理差异自适应地调整迭代权值,使...提出一种基于样本迭代的远距离帧内预测方法,通过迭代预测引入非相邻的像素来作为参考样本,提供更多的空间信息,以改进帧内预测性能。同时,考虑到编码块的纹理复杂度和预测方向之间的联系,根据当前块的纹理差异自适应地调整迭代权值,使得预测精度较为准确。实验结果表明,所提的方法与AVS浅压缩标准算法相比,BDBR(Bjøntegaard Delta Bit Rate)可以节省1.99%,但是时间复杂度仅增加2%。展开更多
针对提高4K超高清电视广播视频压缩效率,减少存储空间和网络带宽这一需求,提出应用音视频编码标准3(Audio Video Coding Standard 3,AVS3)视频编解码技术,利用AVS3编解码标准的高效性,提升4K超高清视频内容的编码质量和传输效率。首先,...针对提高4K超高清电视广播视频压缩效率,减少存储空间和网络带宽这一需求,提出应用音视频编码标准3(Audio Video Coding Standard 3,AVS3)视频编解码技术,利用AVS3编解码标准的高效性,提升4K超高清视频内容的编码质量和传输效率。首先,从节目制播环节入手,通过扩展帧内角度预测和信源动态编码,在保持图像质量的同时降低编码比特率,优化编码过程,节省传输带宽;其次,通过视频分层并行解码和音频解码还放声音技术,提升接收解码及呈现的速度和质量;最后,通过应用实验验证AVS3视频编解码技术在4K超高清电视广播领域的实际效果。展开更多
Background:With growing interest in space exploration,understanding microgravity’s impact on human health is essential.This study aims to investigate gene expression changes and migration and invasion potential infive...Background:With growing interest in space exploration,understanding microgravity’s impact on human health is essential.This study aims to investigate gene expression changes and migration and invasion potential infive thyroid-related cell lines cultured under simulated microgravity.Methods:Five thyroid-related cell lines—normal thyrocytes(Nthy-ori 3-1),papillary thyroid cancer(PTC)cells(SNU-790,TPC-1),poorly differentiated thyroid cancer cell(BCPAP),and anaplastic thyroid cancer cell(SNU-80)—were cultured under simulated microgravity(10-3 g)using a clinostat.Differentially expressed genes(DEGs)were analyzed using cDNA microarray,followed by functional annotation and assessment of aggressiveness via Transwell migration and invasion assays.Results:DEG analysis under simulated microgravity revealed distinct gene expression profiles by gravity condition,with 2980 DEGs in SNU-790,1033 in BCPAP,562 in TPC-1,477 in Nthy-ori 3-1,and 246 in SNU-80,as confirmed by hierarchical clustering.In PTC cell lines(SNU-790,TPC-1),G2–M phase–related genes were upregulated.In non-PTC cell lines(BCPAP,SNU-80),genes associated with innate immune response,Toll-like receptor signaling,were upregulated,whereas Hypoxia-Inducible Factor 1-alpha(HIF-1α)signaling-related genes were downregulated.Additionally,under simulated microgravity,significant migration was observed in SNU-790(3×104 cells)and BCPAP(2×104 and 3×104),while significant invasion occurred in SNU-790,Nthy-ori 3-1,and BCPAP at a seeding density of 2×104.Other conditions showed no significant differences.Conclusion:This study comprehensively evaluates the effects of simulated microgravity using a diverse panel of thyroid-related cell lines.Thesefindings provide valuable insight into how microgravity could influence cancer biology,emphasizing the importance of further research on cancer behavior in space environments and its implications for human health during long-term space missions.展开更多
Coconut(Cocos nucifera L.),a major oil and fruit crop of the Arecaceae family,is extensively cultivated across the Asia—Pacific region.Despite its agricultural importance,genome assembly in coconut remains challengin...Coconut(Cocos nucifera L.),a major oil and fruit crop of the Arecaceae family,is extensively cultivated across the Asia—Pacific region.Despite its agricultural importance,genome assembly in coconut remains challenging due to its large genome size and high proportion of repetitive sequences.Allele-specific expression(ASE)plays a key role in regulating plant development and evolution,yet research on ASE in coconut is limited(Shao et al.,2019;Li et al.,2021;Zhang et al.,2021;Hu et al.,2022).Among phenotypic traits,fruit color is especially important as an indicator of maturity,guiding harvest timing and post-harvest processes(Kapoor et al.,2022).While prior studies have explored various coconut traits such as salt tolerance,fiber content,and plant height(Wang et al.,2021;Yang et al.,2021),investigations into ASE and fruit color remain scarce.展开更多
文摘为解决第三代音视频编码标准(audio video coding standard 3,AVS3)帧内预测的耗时问题,提出一种基于最小编码单元(coding unit,CU)代价的帧内预测并行算法。首先,将图像划分为最小CU。然后,利用原始像素作为参考,并行计算所有最小CU的帧内模式代价。最后,用代价组合的方式快速计算出其他CU的帧内模式优先级,选择最优的15个模式进入粗略模式决策(rough mode decision,RMD)阶段。此外,为减少方法引入的误差,提出了3种优化策略。在预测前对原始像素进行预处理,使其更贴合重构像素;修改帧内预测的代价函数,以更准确地估计每种模式的优先级;大尺寸CU使用顶层的CU代价作为参考,减少CU组合累积的误差。实验结果表明,在码率仅下降0.35%的情况下,整体编码的计算时间减少了27%,有效地减少了帧内预测的耗时并保证了编码质量。
文摘提出一种基于样本迭代的远距离帧内预测方法,通过迭代预测引入非相邻的像素来作为参考样本,提供更多的空间信息,以改进帧内预测性能。同时,考虑到编码块的纹理复杂度和预测方向之间的联系,根据当前块的纹理差异自适应地调整迭代权值,使得预测精度较为准确。实验结果表明,所提的方法与AVS浅压缩标准算法相比,BDBR(Bjøntegaard Delta Bit Rate)可以节省1.99%,但是时间复杂度仅增加2%。
文摘针对提高4K超高清电视广播视频压缩效率,减少存储空间和网络带宽这一需求,提出应用音视频编码标准3(Audio Video Coding Standard 3,AVS3)视频编解码技术,利用AVS3编解码标准的高效性,提升4K超高清视频内容的编码质量和传输效率。首先,从节目制播环节入手,通过扩展帧内角度预测和信源动态编码,在保持图像质量的同时降低编码比特率,优化编码过程,节省传输带宽;其次,通过视频分层并行解码和音频解码还放声音技术,提升接收解码及呈现的速度和质量;最后,通过应用实验验证AVS3视频编解码技术在4K超高清电视广播领域的实际效果。
文摘Background:With growing interest in space exploration,understanding microgravity’s impact on human health is essential.This study aims to investigate gene expression changes and migration and invasion potential infive thyroid-related cell lines cultured under simulated microgravity.Methods:Five thyroid-related cell lines—normal thyrocytes(Nthy-ori 3-1),papillary thyroid cancer(PTC)cells(SNU-790,TPC-1),poorly differentiated thyroid cancer cell(BCPAP),and anaplastic thyroid cancer cell(SNU-80)—were cultured under simulated microgravity(10-3 g)using a clinostat.Differentially expressed genes(DEGs)were analyzed using cDNA microarray,followed by functional annotation and assessment of aggressiveness via Transwell migration and invasion assays.Results:DEG analysis under simulated microgravity revealed distinct gene expression profiles by gravity condition,with 2980 DEGs in SNU-790,1033 in BCPAP,562 in TPC-1,477 in Nthy-ori 3-1,and 246 in SNU-80,as confirmed by hierarchical clustering.In PTC cell lines(SNU-790,TPC-1),G2–M phase–related genes were upregulated.In non-PTC cell lines(BCPAP,SNU-80),genes associated with innate immune response,Toll-like receptor signaling,were upregulated,whereas Hypoxia-Inducible Factor 1-alpha(HIF-1α)signaling-related genes were downregulated.Additionally,under simulated microgravity,significant migration was observed in SNU-790(3×104 cells)and BCPAP(2×104 and 3×104),while significant invasion occurred in SNU-790,Nthy-ori 3-1,and BCPAP at a seeding density of 2×104.Other conditions showed no significant differences.Conclusion:This study comprehensively evaluates the effects of simulated microgravity using a diverse panel of thyroid-related cell lines.Thesefindings provide valuable insight into how microgravity could influence cancer biology,emphasizing the importance of further research on cancer behavior in space environments and its implications for human health during long-term space missions.
基金supported by Central Public-interest Scientific Institution Basal Research Fund(CATAS-Nos.1630152023007,1630152023011,1630152023012,1630152023013)the National Natural Science Foundation of China(Grant No.32071805).
文摘Coconut(Cocos nucifera L.),a major oil and fruit crop of the Arecaceae family,is extensively cultivated across the Asia—Pacific region.Despite its agricultural importance,genome assembly in coconut remains challenging due to its large genome size and high proportion of repetitive sequences.Allele-specific expression(ASE)plays a key role in regulating plant development and evolution,yet research on ASE in coconut is limited(Shao et al.,2019;Li et al.,2021;Zhang et al.,2021;Hu et al.,2022).Among phenotypic traits,fruit color is especially important as an indicator of maturity,guiding harvest timing and post-harvest processes(Kapoor et al.,2022).While prior studies have explored various coconut traits such as salt tolerance,fiber content,and plant height(Wang et al.,2021;Yang et al.,2021),investigations into ASE and fruit color remain scarce.
