检索结果-南通市图书馆

Compressed Data Separation via ℓ_(q)-Split Analysis with ℓ_(∞)-Constraint

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2024年第7期40卷 1655-1673页

作者： Ming yang gu Song Li Jun Hong Lin School of Mathematical Science Zhejiang UniversityHangzhou310027P.R.China Center for Data Science Zhejiang UniversityHangzhou310027P.R.China

In this paper,we study compressed data separation(CDS)problem,i.e.,sparse data separation from a few linear random *** propose the nonconvex ℓ_(q)-split analysis with ℓ_(∞)-constraint and 0 详细信息

In this paper,we study compressed data separation(CDS)problem,i.e.,sparse data separation from a few linear random *** propose the nonconvex ℓ_(q)-split analysis with ℓ_(∞)-constraint and 0

关键词： Data separation ℓ_(q)-split analysis Dantzig selector frames restricted isometry property compressed sensing

Extracting Integrated Features of Electronic Medical Records Big Data for Mortality and Phenotype Prediction

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2024年第3期33卷 776-792页

作者： Fei LI Yiqiang CHEN yang gu Yaowei WANG Institute of Computing Technology University of Chinese Academy of Sciences Pengcheng Laboratory

The key to synthesizing the features of electronic medical records(EMR) big data and using them for specific medical purposes,such as mortality and phenotype prediction,is to integrate the individual medical event and the overall multivariate time series feature extraction automatically,as well as to alleviate data imbalance *** paper provides a general feature extraction method to reduce manual intervention and automatically process large-scale *** processing uses two variational auto-encoders(VAEs) to automatically extract individual and global *** avoids the well-known posterior collapse problem of Transformer VAE through a uniquely designed "proportional and stabilizing" mechanism and forms a unique means to alleviate the data imbalance *** conducted experiments using ICU-STAY patients' data from the MIMIC-Ⅲ database and compared them with the mainstream EMR time series processing *** results show that the method extracts visible and comprehensive features,alleviates data imbalance problems and improves the accuracy in specific predicting tasks.

关键词： Databases Time series analysis MIMICs Manuals Big Data Feature extraction Transformers

Hybrid tri-memristor hyperchaotic map and application in Wasserstein Generative Adversarial Nets

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2024年第6期67卷 1855-1865页

作者： gu yang BAO Han YU XiHong HUA ZhongYun BAO BoCheng XU Quan School of Microelectronics and Control Engineering Changzhou UniversityChangzhou213159China School of Computer Science and Technology Harbin Institute of TechnologyShenzhen518055China

Inspired by basic circuit connection methods,memristors can also be utilized in the construction of complex discrete chaotic *** investigate the dynamical effects of hybrid memristors,we propose two hybrid tri-memristor hyperchaotic(HTMH)mapping structures based on the hybrid parallel/cascade and cascade/parallel operations,*** the HTMH mapping structure with hybrid parallel/cascade operation as an example,this map possesses a spatial invariant set whose stability is closely related to the initial states of the *** distributions and bifurcation behaviours dependent on the control parameters are explored with numerical ***,the memristor initial offset-boosting mechanism is theoretically demonstrated,and memristor initial offset-boosting behaviours are numerically *** results clarify that the HTMH map can exhibit hyperchaotic behaviours and extreme multistability with homogeneous coexisting infinite *** addition,an FPGA hardware platform is fabricated to implement the HTMH map and generate pseudorandom numbers(PRNs)with high ***,the generated PRNs can be applied in Wasserstein generative adversarial nets(WGANs)to enhance training stability and generation capability.

关键词： memristor hybrid tri-memristor map spatial invariant set hyperchaos extreme multistability generative adversarial nets

Semiannual oscillation,annual oscillation,quasibiennial oscillation,and solar cycle variation of the OH airglow emission in the mesopause region

在线全文

学校读者我要写书评

暂无评论

Earth and Planetary Physics 2024年第3期8卷 479-496页

作者： Sheng-yang gu Dong Wang YuSong Qin Liang Tang YaFei Wei XianKang Dou Electronic Information School Wuhan UniversityWuhan 430072China School of Optoelectronic Engineering Chongqing University of Posts and TelecommunicationsChongqing 400065China

The vertically integrated emission rate,centroid altitude,peak emission rate,and peak height of the hydroxyl(OH)airglow were calculated from Thermosphere Ionosphere Mesosphere Energetics and Dynamics(TIMED)/Sounding of the Atmosphere using Broadband Emission Radiometry(SABER)observations to study the seasonal and interannual variations in the intensity and location of the OH *** emission rate is inversely proportional to the height of the emission,with the semiannual oscillation dominating at low latitudes and the annual oscillation dominating at higher *** OH emission is modulated by the quasibiennial oscillation at the equator,and the quasibiennial oscillation signal is weak at other *** represented the vertical transport of atomic oxygen by using atomic oxygen concentrations obtained from a global atmospheric model,the Specified Dynamics Whole Atmosphere Community Climate Model with thermosphere and ionosphere eXtension *** with the amplitudes of the migrating diurnal tide(DW1)calculated from temperature data observed by TIMED/SABER,we found that both the vertical transport of atomic oxygen and DW1 amplitudes in the equatorial region exhibit semiannual oscillation and quasibiennial oscillation,which have a strong correlation with the variations in the amplitude and phase of semiannual oscillation and quasibiennial oscillation in OH *** is likely that the DW1 affects the vertical transport of atomic oxygen that is involved in the reaction to produce O3,thus affecting the OH *** analyzed the relationship between OH emission and solar activity by using the solar radio flux at 10.7 cm as a proxy for solar *** results showed that the OH emission is well correlated with solar activity,and the modulation of OH emission by solar activity has a significant latitudinal *** small correlation between emission height and solar activity indicates that solar activity modulates OH emission mainly thr

关键词： OH airglow semiannual oscillation quasibiennial oscillation solar activity diurnal tide

中国三大城市群PM_(2.5)浓度非线性变化分析

在线全文

学校读者我要写书评

暂无评论

环境科学 2024年第2期45卷 709-720页

作者：吴舒祺顾杨旸张天岳赵文吉首都师范大学资源环境与旅游学院北京100048

以三大城市群为研究区,基于PM_(2.5)浓度数据,利用ITA和Beast方法定量分析PM_(2.5)时间序列的非线性变化过程.结果表明:①三大城市群PM_(2.5)污染程度下降明显,高浓度区域明显缩小;PM_(2.5)浓度空间极化程度降低,空间差异缩小.大多数地... 详细信息

以三大城市群为研究区,基于PM_(2.5)浓度数据,利用ITA和Beast方法定量分析PM_(2.5)时间序列的非线性变化过程.结果表明:①三大城市群PM_(2.5)污染程度下降明显,高浓度区域明显缩小;PM_(2.5)浓度空间极化程度降低,空间差异缩小.大多数地区的PM_(2.5)浓度都具有下降的趋势,但变化程度并不相同.京津冀PM_(2.5)浓度相较于长三角和珠三角,仍处于较高水平.②三大城市群PM_(2.5)浓度具有冬春季高、夏秋季低的季节变化特征.冬季与夏季PM_(2.5)浓度差异明显,PM_(2.5)浓度在夏季的收敛性大于冬季.PM_(2.5)浓度高的区域下降趋势明显,但珠三角的PM_(2.5)浓度下降趋势相较于长三角和京津冀不明显.③三大城市群PM_(2.5)浓度时间序列均具有显著下降趋势,且京津冀>长三角>珠三角;PM_(2.5)浓度在冬季下降趋势最大.PM_(2.5)污染等级越高,下降趋势越明显.④京津冀PM_(2.5)浓度时间序列趋势分量具有两个突变点,季节分量中具有一个突变点;长三角PM_(2.5)浓度时间序列的趋势分量和季节分量均无突变点;珠三角PM_(2.5)浓度时间序列的季节分量无突变点,趋势分量具有一个突变点.结果可为区域空气污染治理相关工作的开展提供科学的参考.

关键词： PM_(2.5) 创新趋势分析(ITA) 季节和趋势突变的贝叶斯估计(Beast) 非线性变化趋势突变

在线全文

学校读者我要写书评

暂无评论

基于优先采样模型的离线强化学习

自动化学报 2024年第1期50卷 143-153页

作者：顾扬程玉虎王雪松中国矿业大学信息与控制工程学院徐州221116

离线强化学习通过减小分布偏移实现了习得策略向行为策略的逼近,但离线经验缓存的数据分布往往会直接影响习得策略的质量.通过优化采样模型来改善强化学习智能体的训练效果,提出两种离线优先采样模型:基于时序差分误差的采样模型和基于... 详细信息

离线强化学习通过减小分布偏移实现了习得策略向行为策略的逼近,但离线经验缓存的数据分布往往会直接影响习得策略的质量.通过优化采样模型来改善强化学习智能体的训练效果,提出两种离线优先采样模型:基于时序差分误差的采样模型和基于鞅的采样模型.基于时序差分误差的采样模型可以使智能体更多地学习值估计不准确的经验数据,通过估计更准确的值函数来应对可能出现的分布外状态.基于鞅的采样模型可以使智能体更多地学习对策略优化有利的正样本,减少负样本对值函数迭代的影响.进一步,将所提离线优先采样模型分别与批约束深度Q学习(Batch-constrained deep Q-learning,BCQ)相结合,提出基于时序差分误差的优先BCQ和基于鞅的优先BCQ.D4RL和Torcs数据集上的实验结果表明:所提离线优先采样模型可以有针对性地选择有利于值函数估计或策略优化的经验数据,获得更高的回报.

关键词：离线强化学习优先采样模型时序差分误差鞅批约束深度Q学习

维普期刊数据库博看期刊

6-Phosphogluconate dehydrogenase 2 bridges the OPP and shikimate pathways to enhance aromatic amino acid production in plants

在线全文

学校读者我要写书评

暂无评论

Science China Life Sciences 2024年

作者： Qian Tang Yuxin Huang Zhuanglin Shen Linhui Sun yang gu Huiqing He Yanhong Chen Jiahai Zhou Limin Zhang Cuihuan Zhao Shisong Ma Yunhai Li Jie Wu Qiao Zhao Shenzhen Key Laboratory of Synthetic Genomics Guangdong Provincial Key Laboratory of Synthetic Genomics Key Laboratory of Quantitative Synthetic Biology Shenzhen Institute of Synthetic BiologyShenzhen Institute of Advanced Technology Chinese Academy of Sciences University of Chinese Academy of Sciences CAS Key Laboratory for Quantitative Engineering Biology Shenzhen Institute of Synthetic Biology Shenzhen Institute of Advanced Technology Chinese Academy of Sciences Key Laboratory of Quantitative Synthetic Biology Shenzhen Institute of Synthetic Biology Shenzhen Institute of Advanced Technology Chinese Academy of Sciences Key Laboratory of Agricultural Microbiology of Heilongjiang Province Northeast Agricultural University Center for Plant Biology School of Life Sciences Tsinghua University State Key Laboratory of Plant Cell and Chromosome Engineering CAS Centre for Excellence in Molecular Plant Biology Institute of Genetics and Developmental Biology The Innovative Academy of Seed Design Chinese Academy of Sciences MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics School of Life Sciences University of Science and Technology of China Innovation Academy for Seed Design Chinese Academy of Sciences

The oxidative pentose phosphate(OPP) pathway provides metabolic intermediates for the shikimate pathway and directs carbon flow to the biosynthesis of aromatic amino acids(AAAs), which serve as basic protein building blocks and precursors of numerous metabolites essential for plant growth. However, genetic evidence linking the two pathways is largely unclear. In this study, we identified 6-phosphogluconate dehydrogenase 2(PGD2), the rate-limiting enzyme of the cytosolic OPP pathway, through suppressor screening of arogenate dehydrogenase 2(adh2) in Arabidopsis. Our data indicated that a single amino acid substitution at position 63(glutamic acid to lysine) of PGD2 enhanced its enzyme activity by facilitating the dissociation of products from the active site of PGD2, thus increasing the accumulation of AAAs and partially restoring the defective phenotype of adh2. Phylogenetic analysis indicated that the point mutation occurred in a well-conserved amino acid residue. Plants with different amino acids at this conserved site of PGDs confer diverse catalytic activities, thus exhibiting distinct AAAs producing capability. These findings uncover the genetic link between the OPP pathway and AAAs biosynthesis through PGD2. The gain-of-function point mutation of PGD2 identified here could be considered as a potential engineering target to alter the metabolic flux for the production of AAAs and downstream compounds.

关键词：

历史文化街区保护与发展的平衡——对马尔罗法的内容解读和历史条件分析

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

自然与文化遗产研究 2024年第2期9卷 57-67页

作者：顾杨诺丁汉大学诺丁汉NG72RD

在我国的文化遗产学术研究中,法国的马尔罗法一直被认为是历史街区概念在世界层面的起源。但在国内现有的相关研究和理论中,只有极少的研究对马尔罗法进行了有限的讨论,还未有对法条进行完整翻译并详细地讲解马尔罗法的相关研究,这使研... 详细信息

在我国的文化遗产学术研究中,法国的马尔罗法一直被认为是历史街区概念在世界层面的起源。但在国内现有的相关研究和理论中,只有极少的研究对马尔罗法进行了有限的讨论,还未有对法条进行完整翻译并详细地讲解马尔罗法的相关研究,这使研究者们利用马尔罗法来阐释文化遗产保护历史中的意义时变得较为困难。文章通过对马尔罗法法律原文的翻译和解读,结合法国文化遗产保护体系的发展历史,以及马尔罗法创立所在时代的法国城市更新状况,尝试去明确解读马尔罗法内容,梳理马尔罗法颁布的相关历史条件,并阐释马尔罗法在文化遗产保护历史中意义,寻求历史文化街区的保护与发展的平衡。

关键词：马尔罗法法国文化遗产保护安德烈·马尔罗历史文化街区

新型基础设施对知识型服务贸易出口质量的影响研究——来自RCEP成员国的经验证据

在线全文

学校读者我要写书评

暂无评论

价格月刊 2024年第5期 21-30页

作者：张美云谷阳西北政法大学经济学院陕西西安710063 西北政法大学义乌研究院陕西西安710063

基于2008—2022年RCEP成员国的面板数据,实证分析新型基础设施对知识型服务出口质量的影响。结果表明:新型基础设施对知识型服务贸易出口质量的提升有显著推动作用。新型基础设施借助信息通信技术的发展,促进知识型服务贸易出口质量,并... 详细信息

基于2008—2022年RCEP成员国的面板数据,实证分析新型基础设施对知识型服务出口质量的影响。结果表明:新型基础设施对知识型服务贸易出口质量的提升有显著推动作用。新型基础设施借助信息通信技术的发展,促进知识型服务贸易出口质量,并且教育水平和研发能力在其中起到了显著的调节作用;与发达国家相比,发展中国家的新型基础设施对知识型服务贸易出口质量的促进作用更为明显;中国新型基础设施与知识型服务贸易发展较为迅速,网络用户量及教育研发投入力度具有明显或一定优势,新型基础设施核心技术及提供的相关服务具有明显或一定劣势。中国要加强新型基础设施建设,提升教育水平和研发能力,深化与RCEP成员国相关领域的合作。

关键词：新型基础设施知识型服务贸易出口质量中介效应调节效应

同方期刊数据库