搜索到146340篇“ SEQUENCES“的相关文章
弹性网络正则化的高维序列因果关联识别研究
2025年
弹性网络正则化方法兼顾了L1正则化与L2正则化的优点,能够解决高维时间序列因果关系分析中共线性、过度拟合与信息冗余等问题,有效发掘高维序列之间的主要关联关系。首先,基于VAR模型与长期格兰杰因果关联网络,阐述高维序列因果关联识别的方法;其次,讨论了弹性网络正则化如何解决高维序列因果关系建模的弊端,融合L1与L2正则化的主要特点;最后,结合多维大宗商品期货价格日度波动率序列,探索了弹性网络正则化在高维序列因果关联识别的应用,并与其他正则化方法进行比较。结果表明,弹性网络正则化方法避免了信息冗余与“过度稀疏化”的问题,识别与提炼商品价格波动因果关联网络中的主要影响节点与传导关系,挖掘序列关系网络中的主要因果关联。
张居营安风楼
关键词:正则化
DTI联合3D-TOF及3D-SSFP序列对高血压伴三叉神经痛诊断价值的研究
2025年
目的研究扩散张量成像(DTI)技术联合三维时间飞跃(3D-TOF)序列及三维稳态自由进动序列技术(3D SSFP)对原发性高血压伴三叉神经痛(PH-TN)的诊断价值。方法搜集64例PH-TN患者作为实验组及64例原发性三叉神经痛(TN)患者作为对照组,分别行DTI联合3D-TOF及3D-SSFP序列扫描,记录责任血管、血管神经受压程度分级及测量两组患侧和健侧的血管神经受压处的各向异性分数(FA)和表观扩散系数(ADC)值。结果PH-TN组和TN组患侧小脑上动脉压迫神经较多,占位分别为67.9%、67.3%;PH-TN组和TN组患侧血管神经压迫较健侧多,且PH-TN组患侧血管神经压迫分级Ⅱ级、Ⅲ级较TN组患侧多,差异有统计学意义(P<0.05);PH-TN组患侧FA值(0.296±0.119)小于健侧FA值(0.346±0.125)、PH-TN组患侧ADC值(2.27±0.43)×10-3大于健侧ADC值(2.03±0.4)×10-3,FA及ADC值差异具有统计学意义(P<0.05);TN组患侧FA值(0.290±0.107)小于健侧FA值(0.393±0.142),TN组患侧ADC值(2.35±0.32)×10-3大于健侧ADC值(1.99±0.41)×10-3,FA及ADC值差异具有统计学意义(P<0.05)。结论通过DTI联合3D-TOF及3D-SSFP扫描,得出PH-TN组患侧II级、III级血管神经压迫者较TN组患侧多,且三者联合扫描可以从直观及微观层面对TN的病因诊断做出有价值的影像学参考。
徐天天李立韩彦舟蒋新新商飞翔钱伟军
关键词:三叉神经高血压DTI3D-TOF
等价数列的性质及应用
2024年
将集合论中的等价关系引入到数学分析中,给出了等价数列的概念及若干性质,并举例说明了等价数列在数学分析、线性代数和泛函分析中的应用.
徐贝宁许绍元
关键词:等价关系巴拿赫空间数列收敛
基于参考的基因序列压缩算法综述
2024年
【背景】在过去的二十年里,DNA测序技术持续发展,海量生物序列数据的产生给数据存储、管理和传输带来了严峻的挑战。【目的】本文主要总结近十五年基于参考的基因序列压缩算法,以寻求加速生物数据共享和降低存储成本的方法。【方法】本文从算法的发展角度出发,按照不同算法所使用的关键技术和针对压缩优化的方案进行分类。通过实验验证当前主流算法的性能,揭示当前基于参考的压缩算法所存在的问题。提出一些值得探讨的研究方向,并对未来的研究方向进行了展望。【结果】本文分析了已有基于参考的基因序列压缩算法使用的技术,包括基于单核苷酸多态性、检测最大精确匹配、分段/分块处理和基于LZ77等技术。并对几种较著名的算法进行了复现,发现这些算法倾向于在基准数据集上表现出高压缩比,但在普通数据集上的压缩比普遍不高。【结论】目前已有的基于参考的基因序列压缩算法在理论上可以加速数据传输效率、节约存储成本,但是实用性存疑。须继续改进公共子序列匹配方式以提升对普通数据集的支持,增加预处理参考序列步骤以降低匹配时间开销。
蔡佳威胡川王华进沈志宏
关键词:DNA序列
Enhancing whole yeast genome rearrangements through multiple LoxPsym sequences
2024年
Genomic rearrangements play a significant role in disease,evolution,and tumorigenesis(Mani and Chinnaiyan,2010).While single nucleotide polymorphisms(SNPs)and small insertions/deletions contribute substantially to genetic variation,discerning the independent impact of structural variations poses a challenge.
Bing-Zhi LiYing-Jin Yuan
关键词:INSERTIONSEQUENCES
序列:脚本与故事的界面--戴维·赫尔曼的序列研究
2024年
戴维·赫尔曼将脚本、序列与故事视为建构故事世界的叙事微观设计,探究了脚本如何通过激活序列接受者存储在大脑中的世界知识,提示序列接受者将序列阐释为故事,是一个脚本与故事的界面研究。赫尔曼不仅考察了脚本和叙事性的内在联系,还从历时和共时层面讨论了脚本对文学阐释的影响。赫尔曼的这项研究在一定程度上为后经典叙事学的建立奠定了基础,是他力图开创认知叙事学研究范式的一次成功尝试。
宋杰
关键词:脚本故事叙事性文学阐释
Pig pangenome graph reveals functional features of non‑reference sequences
2024年
Background The reliance on a solitary linear reference genome has imposed a significant constraint on our compre-hensive understanding of genetic variation in animals.This constraint is particularly pronounced for non-reference sequences(NRSs),which have not been extensively studied.Results In this study,we constructed a pig pangenome graph using 21 pig assemblies and identified 23,831 NRSs with a total length of 105 Mb.Our findings revealed that NRSs were more prevalent in breeds exhibiting greater genetic divergence from the reference genome.Furthermore,we observed that NRSs were rarely found within coding sequences,while NRS insertions were enriched in immune-related Gene Ontology terms.Notably,our investigation also unveiled a close association between novel genes and the immune capacity of pigs.We observed substantial differences in terms of frequencies of NRSs between Eastern and Western pigs,and the heat-resistant pigs exhibited a substantial number of NRS insertions in an 11.6 Mb interval on chromosome X.Additionally,we discovered a 665 bp insertion in the fourth intron of the TNFRSF19 gene that may be associated with the ability of heat tolerance in South-ern Chinese pigs.Conclusions Our findings demonstrate the potential of a graph genome approach to reveal important functional features of NRSs in pig populations.
Jian MiaoXingyu WeiCaiyun CaoJiabao SunYuejin XuZhe ZhangQishan WangYuchun PanZhen Wang
Phylogenetic, phylogeographic and divergence time analysis of Anopheles subpictus species complex using ITS2 and COI sequences
2024年
Objective:To address the phylogenetic and phylogeographic relationship between different lineages of Anopheles(An.)subpictus species complex in most parts of the Asian continent by maximum utilization of Internal Transcriber Spacer 2(ITS2)and cytochrome C oxidase I(COI)sequences deposited at the GenBank.Methods:Seventy-five ITS2,210 COI and 26 concatenated sequences available in the NCBI database were used.Phylogenetic analysis was performed using Bayesian likelihood trees,whereas median-joining haplotype networks and time-scale divergence trees were generated for phylogeographic analysis.Genetic diversity indices and genetic differentiation were also calculated.Results:Two genetically divergent molecular forms of An.subpictus species complex corresponding to sibling species A and B are established.Species A evolved around 37-82 million years ago in Sri Lanka,India,and the Netherlands,and species B evolved around 22-79 million years ago in Sri Lanka,India,and Myanmar.Vietnam,Thailand,and Cambodia have two molecular forms:one is phylogenetically similar to species B.Other forms differ from species A and B and evolved recently in the above mentioned countries,Indonesia and the Philippines.Genetic subdivision among Sri Lanka,India,and the Netherlands is almost absent.A substantial genetic differentiation was obtained for some populations due to isolation by large geographical distances.Genetic diversity indices reveal the presence of a long-established stable mosquito population,at mutation-drift equilibrium,regardless of population fluctuations.Conclusions:An.subpictus species complex consists of more than two genetically divergent molecular forms.Species A is highly divergent from the rest.Sri Lanka and India contain only species A and B.
Lihini Sandaleka MuthukumaranaMethsala Madurangi WedageSamanthika RathnayakeNissanka Kolitha De Silva
关键词:ITS2COIPHYLOGEOGRAPHY
LMR-CBT: learning modality-fused representations with CB-Transformer for multimodal emotion recognition from unaligned multimodal sequences被引量:1
2024年
Learning modality-fused representations and processing unaligned multimodal sequences are meaningful and challenging in multimodal emotion recognition.Existing approaches use directional pairwise attention or a message hub to fuse language,visual,and audio modalities.However,these fusion methods are often quadratic in complexity with respect to the modal sequence length,bring redundant information and are not efficient.In this paper,we propose an efficient neural network to learn modality-fused representations with CB-Transformer(LMR-CBT)for multimodal emotion recognition from unaligned multi-modal sequences.Specifically,we first perform feature extraction for the three modalities respectively to obtain the local structure of the sequences.Then,we design an innovative asymmetric transformer with cross-modal blocks(CB-Transformer)that enables complementary learning of different modalities,mainly divided into local temporal learning,cross-modal feature fusion and global self-attention representations.In addition,we splice the fused features with the original features to classify the emotions of the sequences.Finally,we conduct word-aligned and unaligned experiments on three challenging datasets,IEMOCAP,CMU-MOSI,and CMU-MOSEI.The experimental results show the superiority and efficiency of our proposed method in both settings.Compared with the mainstream methods,our approach reaches the state-of-the-art with a minimum number of parameters.
Ziwang FUFeng LIUQing XUXiangling FUJiayin QI
迭代数列收敛性
2024年
迭代数列的收敛性问题是数列极限中一类常见题型,也是其中的一个难点.整理了迭代数列收敛性问题中的一些常见解题方法和规律,并结合具体的题目给出了若干分析和思考.
康红梅顾怡
关键词:迭代数列不动点

相关作者

李德铢
作品数:216被引量:2,987H指数:23
供职机构:中国科学院昆明植物研究所
研究主题:英文 竹亚科 测序 果实 离体保存
张亚平
作品数:461被引量:3,639H指数:35
供职机构:云南大学
研究主题:线粒体DNA 引物 猪产仔数 MTDNA 性状
章璞
作品数:20被引量:11H指数:2
供职机构:上海交通大学理学院数学系
研究主题:倾斜代数 箭图 HOCHSCHILD上同调群 同调群 倾斜模
杨君兴
作品数:209被引量:822H指数:17
供职机构:中国科学院昆明动物研究所
研究主题:鱼类 滇池金线鲃 白鱼 催产剂 鱼苗饲养
马国龙
作品数:20被引量:83H指数:6
供职机构:扬州大学动物科学与技术学院
研究主题:细胞色素B基因 多态性研究 基因序列分析 大额牛 分子系统发生