检索结果-南通市图书馆

Embedding Tensors on 3-Hom-Lie Algebras

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

Journal of Mathematical Research with Applications 2024年第2期44卷 187-198页

作者： Wen TENg Jiulin jin Yu ZHANg school of Mathematics and statistics Guizhou University of Finance and Economics school of Science Guiyang University

In this paper, we introduce the notion of embedding tensors on 3-Hom-Lie algebras and show that embedding tensors induce naturally 3-Hom-Leibniz algebras. Moreover, the cohomology theory of embedding tensors on 3-Hom-Lie algebras is defined. As an application,we show that if two linear deformations of an embedding tensor on a 3-Hom-Lie algebra are equivalent, then their infinitesimals belong to the same cohomology class in the first cohomology group.

关键词： 3-Hom-Lie algebra embedding tensor representation cohomology deformation

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Rssler混沌系统的追踪控制与同步

物理学报 2002年第4期51卷 749-752页

作者：陈士华谢进陆君安刘杰武汉大学数学统计学院武汉430072

对R ssler混沌系统进行控制 ,使之追踪任意参考信号 ,讨论了该控制系统的自同步以及与Lorenz混沌系统的异结构混沌同步问题 ,并利用Lyapunov方法证明了该控制系统指数收敛到参考信号 .

关键词： Roessler混沌系统 Lorenz混沌系统追踪控制同步混沌控制

Quadrature Formula of Singular Integral Based on Rational Interpolation

在线全文

学校读者我要写书评

暂无评论

Wuhan university Journal of Natural Sciences 2002年第3期7卷 253-260页

作者： Du jin-yuan Zhang Meng Wuhan university School of Mathematics and Statistics Wuhan Hubei China (GRID:grid.49470.3e) (ISNI:***)

We construct a quadrature formula of the singular integral with the Chebyshev weight of the second kind by using Lagrange interpolation based on the rational system {1/(x?a 1), 1/(x?a 2), …}, and both the remainder a... 详细信息

关键词： rational system generalized chebyshev polynomial lagrange interpolation singular quadrature formula

基于EEg的警觉度客观检测与通道筛选技术研究

在线全文

学校读者我要写书评

暂无评论

载人航天 2024年第4期30卷 434-442页

作者：孙子恒代艳莹焦学军姜劲綦宏志余辉周鹏天津大学医学工程与转化医学研究院天津300072 天津大学精密仪器与光电子工程学院天津300072 中国航天员科研训练中心人因工程重点实验室北京100094 天津市智能中医诊疗技术与装备重点实验室天津300072

在航天领域,警觉度的降低会影响航天员的工效,还可能引发重大安全事故。针对航天领域的警觉度客观检测技术进行研究,设计了多轮次PVT和3⁃back任务结合的警觉度建模实验,并全程采集EEg信号和行为学数据,该实验范式成功诱导了37名志愿者... 详细信息

在航天领域,警觉度的降低会影响航天员的工效,还可能引发重大安全事故。针对航天领域的警觉度客观检测技术进行研究,设计了多轮次PVT和3⁃back任务结合的警觉度建模实验,并全程采集EEg信号和行为学数据,该实验范式成功诱导了37名志愿者警觉度下降,并伴随着大脑快波成分减少,慢波成分增加,复杂度降低等现象,在额叶、颞叶和枕叶区域变化明显。使用方差分析(ANOVA)结合支持向量机(SVM)对单个特征建模的方法筛选出了6个警觉度敏感特征,在此基础上使用SVM⁃RFECV方法筛选出了12个警觉度敏感导联,最后使用SVM进行警觉度客观检测模型的构建。结果显示:特征筛选前的平均分类正确率为83.10%,在导联筛选后为87.16%,提升了约4%。特征筛选和导联筛选工作有效地提高了模型的综合性能,同时简化了脑电采集流程,减少了后续数据处理的工作量和时间成本。

关键词：脑电警觉度支持向量机特征筛选导联筛选

THE LIMITINg PROFILE OF SOLUTIONS FOR SEMILINEAR ELLIPTIC SYSTEMS WITH A SHRINKINg SELF-FOCUSINg CORE

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2024年第2期44卷 583-608页

作者：金可石影谢华飞 Zhejiang College Shanghai University of Finance and EconomicsJinhua321013China school of Mathematical Sciences Zhejiang Normal UniversityJinhua321004China school of Mathematics and statistics Nanyang Normal UniversityNanyang473061China

In this paper,we consider the semilinear elliptic equation systems{△u+u=αQ_(n)(x)|u|^(α-2)|v|^(β)u in R^(N),-△v+v=βQ(x)|u|^(α)|v|^(β-2)v in R^(N),where N≥3,α,β>1,α+β2^(*),2^(*)=2N/N-2 and Q_(n) are bounded given functions whose self-focusing cores{x∈R^(N)|Q_(n)(x)>0} shrink to a set with finitely many points as n→∞.Motivated by the work of Fang and Wang[13],we use variational methods to study the limiting profile of ground state solutions which are concentrated at one point of the set with finitely many points,and we build the localized concentrated bound state solutions for the above equation systems.

关键词： Schrödinger system ground states solutions bound state solutions

在线全文

学校读者我要写书评

暂无评论

概率原则下基于投资者偏好的组合投资选择

系统工程学报 2005年第5期20卷 544-548页

作者：徐金红徐维军李引生西安交通大学管理学院西安交通大学机械学院陕西西安710049

基于理性投资者的基本行为特征,从投资者真实的投资心理出发,给出了概率原则下基于投资者偏好的组合投资选择模型.在该模型中,收益与风险权重大小可以根据投资者对收益与风险的不同偏好程度来确定.对于证券收益率服从任意分布的情形,运... 详细信息

基于理性投资者的基本行为特征,从投资者真实的投资心理出发,给出了概率原则下基于投资者偏好的组合投资选择模型.在该模型中,收益与风险权重大小可以根据投资者对收益与风险的不同偏好程度来确定.对于证券收益率服从任意分布的情形,运用遗传算法的思想设计出了该模型的有效求解算法,并通过Mat-lab语言实现,从而得出投资组合选择.最后,对不同风险偏好下的解进行了数值比较分析.

关键词：概率原则组合投资投资者偏好遗传算法 Matlab语言

Epidemiological feature analysis of SVEIR model with control strategy and variant evolution

在线全文

学校读者我要写书评

暂无评论

Infectious Disease Modelling 2024年第3期9卷 689-700页

作者： Kaijing Chen Fengying Wei Xinyan Zhang Hao jin Zuwen Wang Yue Zuo Kai Fan school of Mathematics and statistics Fuzhou UniversityFuzhou350116FujianChina Key Laboratory of Operations Research and Control of Universities in Fujian Fuzhou UniversityFuzhou350116FujianChina Center for Applied Mathematics of Fujian Province Fuzhou UniversityFuzhou350116FujianChina jinzhou Center for Disease Control and Prevention Jinzhou121000LiaoningChina

The complex interactions were performed among non-pharmaceutical interventions,vaccinations,and hosts for all epidemics in china's Mainland during the spread of ***,the small-scale epidemic in the city described by SVEIR model was less found in the current *** SVEIR model with control was established to analyze the dynamical and epidemiological features of two epidemics in jinzhou City led by Omicron variants before and after Twenty *** this study,the total population(N)of jinzhou City was divided into five compartments:the susceptible(S),the vaccinated(V),the exposed(E),the infected(I),and the recovered(R).By surveillance data and the SVEIR model,three methods(maximum likelihood method,exponential growth rate method,next generation matrix method)were governed to estimate basic reproduction number,and the results showed that an increasing tendency of basic reproduction number from Omicron BA.5.2 to Omicron ***,the effective reproduction number for two epidemics were investigated by surveillance data,and the results showed that jinzhou wave 1 reached the peak on November 1 and was controlled 7 days later,and that jinzhou wave 2 reached the peak on November 28 and was controlled 5 days ***,the impacts of non-pharmaceutical interventions(awareness delay,peak delay,control intensity)were discussed extensively,the variations of infection scales for Omicron variant and Eg.5 variant were also ***,the investigations on peaks and infection scales for two epidemics in dynamic zero-COVID policy were operated by the SVEIR model with *** investigations on public medical requirements of jinzhou City and Liaoning Province were analyzed by using SVEIR model without control,which provided a possible perspective on variant evolution in the future.

关键词： COVID-19 SVEIR model Twenty measures Control strategy Variant evolution

Valuation and comparison of the actual and optimal control strategy in an emerging infectious disease:Implication from a COVID-19 transmission model

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

Infectious Disease Modelling 2024年第2期9卷 354-372页

作者： Lili Liu Xi Wang Ou Liu Yazhi Li Zhen jin Sanyi Tang Xia Wang Shanxi Key Laboratory of Mathematical Techniques and Big Data Analysis on Disease Control and Prevention Complex Systems Research CenterShanxi UniversityTaiyuan030006China school of Mathematical Sciences Shanxi UniversityTaiyuan030006China school of Mathematics and statistics Qiannan Normal University for NationalitiesGuizhouDuyun558000China school of Mathematics and statistics Shaanxi Normal UniversityXi'an710119China

To effectively combat emerging infectious diseases like COVID-19,it is crucial to adopt strict prevention and control measures promptly to effectively contain the spread of the *** this paper,we propose a transmission model to investigate the influence of two control strategies:reducing contact numbers and improving medical *** examine these strategies in terms of constant control and time-varying *** sensitivity analysis on two reproduction numbers of the model with constant control,we demonstrate that reducing contact numbers is more effective than improving medical ***,these two constant controls significantly influence the peak values and timing of ***,intensifying control measures can reduce peak values,albeit at the expense of delaying the peak *** the model with time-varying control,we initially explore the corresponding optimal control problem and derive the characteristic expression of optimal ***,we utilize real data from January 10th to April 12th,2020,in Wuhan city as a case study to perform parameter estimation by using our proposed improved *** findings illustrate that implementing optimal control measures can effectively reduce infections and deaths,and shorten the duration of the ***,we numerically explore that implementing control measures promptly and increasing intensity to reduce contact numbers can make actual control be more closer to optimized ***,we utilize the real data from October 31st to November 18th,2021,in Hebei province as a second case study to validate the feasibility of our proposed suggestions.

关键词： Emerging epidemic Transmission model Sensitivity analysis Actual control Optimal control

BP神经网络修剪算法筛选白血病预后危险因素

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

复旦学报（医学版） 2003年第2期30卷 154-157页

作者：邓伟金丕焕林果为复旦大学公共卫生学院卫生统计与社会医学教研室上海200032 复旦大学公共卫生学院附属华山医院血液科上海200040

目的　通过单层BP网络的修剪算法 ,进行白血病预后危险因素筛选 ,并讨论修剪算法在医学统计中的应用及其与逐步logistic回归的联系。方法　对上海市 1985 - 1995年间部分初发白血病病人的 6个月预后及可能的影响因素进行分析 ,分别用... 详细信息

目的　通过单层BP网络的修剪算法 ,进行白血病预后危险因素筛选 ,并讨论修剪算法在医学统计中的应用及其与逐步logistic回归的联系。方法　对上海市 1985 - 1995年间部分初发白血病病人的 6个月预后及可能的影响因素进行分析 ,分别用修剪算法和逐步logistic回归拟合不同的模型 ,利用ROC曲线下面积比较各个模型的判别和预测效果。结果　利用修剪算法 ,可得到与逐步logistic回归相同的BP模型结构 ;应用不同的修剪参数得到含不同连接的BP网络模型 ,最终稳定于含 10个连接的模型。所有修剪的BP网络对测试集的判别效果均好于逐步logistic回归。结论　修剪算法可以进行变量筛选 ,并可应用于弱影响因素的探索。修剪的单层BP网络的权重系数与逐步logistic回归的回归系数相同。

关键词：白血病预后危险因素 BP神经网络修剪算法