期刊文献+
共找到2,509篇文章
< 1 2 126 >
每页显示 20 50 100
Halton-type sequences from global function fields 被引量:1
1
作者 NIED ERREITER Harald YEO Anderson SiangJing 《Science China Mathematics》 SCIE 2013年第7期1467-1476,共10页
For any prime power q and any dimension s≥1, a new construction of (t, s)-sequences in base q using global function fields is presented. The construction yields an analog of Halton sequences for global function field... For any prime power q and any dimension s≥1, a new construction of (t, s)-sequences in base q using global function fields is presented. The construction yields an analog of Halton sequences for global function fields. It is the first general construction of (t, s)-sequences that is not directly based on the digital method. The construction can also be put into the framework of the theory of (u, e, s)-sequences that was recently introduced by Tezuka and leads in this way to better discrepancy bounds for the constructed sequences. 展开更多
关键词 low-discrepancy sequence (t s)-sequence Halton sequence global function field
原文传递
A Parameter-Free Filled Function for Unconstrained Global Optimization 被引量:9
2
作者 安澜 张连生 +2 位作者 陈美霖 Chen mei-lin 《Journal of Shanghai University(English Edition)》 CAS 2004年第2期117-123,共7页
The filled function method is an approach for finding a global minimum of multi-dimensional functions. With more and more relevant research, it becomes a promising way used in unconstrained global optimization. Some f... The filled function method is an approach for finding a global minimum of multi-dimensional functions. With more and more relevant research, it becomes a promising way used in unconstrained global optimization. Some filled functions with one or two parameters have already been suggested. However, there is no certain criterion to choose a parameter appropriately. In this paper, a parameter-free filled function was proposed. The definition of the original filled function and assumptions of the objective function given by Ge were improved according to the presented parameter-free filled function. The algorithm and numerical results of test functions were reported. Conclusions were drawn in the end. Key words global optimization - filled function method - local minimizer MSC 2000 90C30 展开更多
关键词 global optimization filled function method local minimizer
在线阅读 下载PDF
A New Filled Function with One Parameter to Solve Global Optimization 被引量:6
3
作者 Hongwei Lin Huirong Li 《Open Journal of Optimization》 2015年第1期10-20,共11页
In this paper, a new filled function with only one parameter is proposed. The main advantages of the new filled function are that it not only can be analyzed easily, but also can be approximated uniformly by a continu... In this paper, a new filled function with only one parameter is proposed. The main advantages of the new filled function are that it not only can be analyzed easily, but also can be approximated uniformly by a continuously differentiable function. Thus, a minimizer of the proposed filled function can be obtained easily by using a local optimization algorithm. The obtained minimizer is taken as the initial point to minimize the objective function and a better minimizer will be found. By repeating the above processes, we will find a global minimizer at last. The results of numerical experiments show that the new proposed filled function method is effective. 展开更多
关键词 global Optimization FILLED function Method SMOOTHING Technique global Minimize Local MINIMIZER
在线阅读 下载PDF
The Global Stability of Predator-Prey System of Gause-Type with Holling Ⅲ Functional Response 被引量:1
4
作者 Feng Jian\|wen, Zen Xian\|wu College of Mathematics and Computer Sicence, Wuhan University, Wuhan 430072,China 《Wuhan University Journal of Natural Sciences》 CAS 2000年第3期271-277,共7页
This paper deals with the questio n of global stability of the positive locally asymptotically stable equilibrium in a class of predator\|prey system of Gause\|typ e with Holling Ⅲ functional response. The Dulac'... This paper deals with the questio n of global stability of the positive locally asymptotically stable equilibrium in a class of predator\|prey system of Gause\|typ e with Holling Ⅲ functional response. The Dulac's criterion is applied and lia punov functions are constructed to establish the global stability. 展开更多
关键词 global stability functional response predtor\|prey system limit cycle
在线阅读 下载PDF
FILLED FUNCTIONS FOR UNCONSTRAINED GLOBAL OPTIMIZATION 被引量:1
5
作者 XuZheng XuChengxian 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2000年第3期307-318,共12页
The paper is concerned with the filled functions for global optimization of a continuous function of several variables.More general forms of filled functions are presented for smooth and nonsmooth optimizations.These ... The paper is concerned with the filled functions for global optimization of a continuous function of several variables.More general forms of filled functions are presented for smooth and nonsmooth optimizations.These functions have either two adjustable parameters or one adjustable parameter.Conditions on functions and on the values of parameters are given so that the constructed functions are desired filled functions. 展开更多
关键词 global optimization filled function nonsmooth optimization basin.
在线阅读 下载PDF
Evaluation of Right Ventricular Global Longitudinal Function in Patients with Tetralogy of Fallot by Two-dimensional Ultrasound Speckle Tracking Imaging 被引量:2
6
作者 李玉曼 谢明星 +7 位作者 王新房 吕清 卢晓芳 杨亚利 马红 方凌云 张静 李卫芹 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2010年第1期126-131,共6页
Quantification of right ventricular(RV)volume and function remains a challenge because of RV complex geometry by conventional echocardiography.The purpose of this study was to assess RV global longitudinal function in... Quantification of right ventricular(RV)volume and function remains a challenge because of RV complex geometry by conventional echocardiography.The purpose of this study was to assess RV global longitudinal function in patients with tetralogy of Fallot(TOF)by 2-dimensional ultrasound speckle tracking imaging(STI).Thirty-eight patients with TOF were enrolled in this study and divided into child group(n=25)and adult group(n=13)according to age.Thirty-eight age-and sex-matched normal subjects were selected as c... 展开更多
关键词 ECHOCARDIOGRAPHY tetralogy of Fallot ventricular function global RIGHT 2-dimensional speckle tracking
暂未订购
Green’s Function Technique and Global Optimization in Reconstruction of Elliptic Objects in the Regular Triangle
7
作者 Antonio Scalia Mezhlum A. Sumbatyan 《Applied Mathematics》 2011年第3期294-302,共9页
The reconstruction problem for elliptic voids located in the regular (equilateral) triangle is studied. A known point source is applied to the boundary of the domain, and it is assumed that the input data is obtained ... The reconstruction problem for elliptic voids located in the regular (equilateral) triangle is studied. A known point source is applied to the boundary of the domain, and it is assumed that the input data is obtained from the free-surface input data over a certain finite-length interval of the outer boundary. In the case when the boundary contour of the internal object is unknown, we propose a new algorithm to reconstruct its position and size on the basis of the input data. The key specific character of the proposed method is the construction of a special explicit-form Green's function satisfying the boundary condition over the outer boundary of the triangular domain. Some numerical examples demonstrate good stability of the proposed algorithm. 展开更多
关键词 RECONSTRUCTION global Optimization Green's function TRIANGULAR Domain Boundary Integral
在线阅读 下载PDF
Global Avalanche Characteristics of Boolean Functions by Concatenation
8
作者 Zepeng Zhuo Jinfeng Chong +1 位作者 Ruirui Yu Mingsheng Ren 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2016年第3期91-96,共6页
In order to measure the correlation propeties of two Boolean functions,the global avalanche characteristics of Boolean functions constructed by concatenation are discussed,i.e.,f_1‖f_2and f_1‖f_2‖f_3‖f_4.Firstly,f... In order to measure the correlation propeties of two Boolean functions,the global avalanche characteristics of Boolean functions constructed by concatenation are discussed,i.e.,f_1‖f_2and f_1‖f_2‖f_3‖f_4.Firstly,for the function f = f_1‖f_2,the cross-correlation function of f_1,f_2 in the special condition are studied.In this case,f,f_1,f_2 must be in desired form.By computing their sum-of-squares indicators,the crosscorrelation function between f_1,f_2 is obtained.Secondly,for the function g = f_1‖f_2‖f_3‖f_4,by analyzing the relation among their auto-correlation functions,their sum-of-squares indicators are investigated.Based on them,the sum-of-squares indicators of functions obtained by Canteaut et al.are investigated.The results show that the correlation property of g is good when the correlation properties of Boolean functions f_1,f_2,f_3,f_4 are good. 展开更多
关键词 BOOLEAN function CROSS-CORRELATION function global AVALANCHE characteristics sum-of-squaresindicator
在线阅读 下载PDF
Integral Global Minimization of Constrained Problems with Discontinuous Penalty Functions 被引量:1
9
作者 吴斌 崔洪泉 郑权 《Journal of Shanghai University(English Edition)》 CAS 2005年第5期385-390,共6页
A class of discontinuous penalty functions was proposed to solve constrained minimization problems with the integral approach to global optimization, m-mean value and v-variance optimality conditions of a constrained ... A class of discontinuous penalty functions was proposed to solve constrained minimization problems with the integral approach to global optimization, m-mean value and v-variance optimality conditions of a constrained and penalized minimization problem were investigated. A nonsequential algorithm was proposed. Numerical examples were given to illustrate the effectiveness of the algorithm. 展开更多
关键词 integral global minimization constrained minimization problems discontinuous penalty functions.
在线阅读 下载PDF
Global Exponential Periodicity of a Class of Recurrent Neural Networks with Non-Monotone Activation Functions and Time-Varying Delays
10
作者 LI Biwen 《Wuhan University Journal of Natural Sciences》 CAS 2009年第6期475-480,共6页
The stability of a periodic oscillation and the global exponential class of recurrent neural networks with non-monotone activation functions and time-varying delays are analyzed. For two sets of activation functions, ... The stability of a periodic oscillation and the global exponential class of recurrent neural networks with non-monotone activation functions and time-varying delays are analyzed. For two sets of activation functions, some algebraic criteria for ascertaining global exponential periodicity and global exponential stability of the class of recurrent neural networks are derived by using the comparison principle and the theory of monotone operator. These conditions are easy to check in terms of system parameters. In addition, we provide a new and efficacious method for the qualitative analysis of various neural networks. 展开更多
关键词 recurrent neural networks non-monotone activation functions global exponential stability comparison principle monotone operator
原文传递
A Global Minimization Algorithm for Empirical Contact Potential Functions
11
作者 WANG Yu-hong LI Wei 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2006年第2期248-250,共3页
Global minimization algorithm is indispensable for solving protein folding problems based on thermodynamic hypothesis. A contact difference (CD) based on pseudo potential function, for simulating empirical contact p... Global minimization algorithm is indispensable for solving protein folding problems based on thermodynamic hypothesis. A contact difference (CD) based on pseudo potential function, for simulating empirical contact potential functions and testing global minimization algorithm was proposed. The present article describes a conformational sampiing and global minimization algorithm, which is called WL, based on Monte Carlo simulation and simulated annealing. It can be used to locate CD's globe minimum and refold extended protein structures, as small as 0. 03 nm, from the native structures, back to ones with root mean square distance(RMSD). These results demonstrate that the global minimization problems for empirical contact potential functions may be solvable. 展开更多
关键词 global minimization Contact potential function Simulated annealing Monte Carlo simulation
在线阅读 下载PDF
A Global Minimization Algorithm for Empirical Contact Potential Functions
12
作者 WANGYu-hong LIWei 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2004年第5期572-574,共3页
Global minimization algorithm is indispensable to solving the protein folding problem based upon thermodynamic hypothesis. Here we propose a pseudo potential function, contact difference(CD), for simulating empirical ... Global minimization algorithm is indispensable to solving the protein folding problem based upon thermodynamic hypothesis. Here we propose a pseudo potential function, contact difference(CD), for simulating empirical contact potential functions and testing global minimization algorithm. The present paper covers conformational sampling and global minimization algorithm called BML03, based upon Monte Carlo and simulated annealing, which is able to locate CD′s global minimum and refold extended protein structures into ones with root mean square distance(RMSD) as small as 0.03 nm from the native structures. For empirical contact potential functions, these results demonstrate that their global minimization problems may be solvable. 展开更多
关键词 global minimization Contact potential function Simulated annealing Monte Carlo simulation
在线阅读 下载PDF
Effect of Weight Function in Nonlinear Part on Global Solvability of Cauchy Problem for Semi-Linear Hyperbolic Equations
13
作者 Akbar B. Aliev Anar A. Kazimov 《International Journal of Modern Nonlinear Theory and Application》 2013年第1期102-106,共5页
In this paper, we investigate the effect of weight function in the nonlinear part on global solvability of the Cauchy problem for a class of semi-linear hyperbolic equations with damping.
关键词 CAUCHY Problem Wave EQUATION global SOLVABILITY Weight function SEMI-LINEAR Hyperbolic EQUATION
在线阅读 下载PDF
Global innovators to feature in Intertextile Shanghai's Functional Lab
14
作者 Flora 《China Textile》 2016年第8期32-33,共2页
Heading into the second half of the year,the global apparel fabrics and accessories industry’s attention has begun to focus on the 2016 Autumn Edition of Intertextile Shanghai Apparel Fabrics which will be held from... Heading into the second half of the year,the global apparel fabrics and accessories industry’s attention has begun to focus on the 2016 Autumn Edition of Intertextile Shanghai Apparel Fabrics which will be held from 11–13 October.Over 5,000 exhibitors from more than 25 countries and regions will take part and showcase an all-encompassing range of products across 260,000 sqm.of exhibition space at the Nation Exhibition and Convention Center(Shanghai).To 展开更多
关键词 In WILL global innovators to feature in Intertextile Shanghai’s functional Lab
在线阅读 下载PDF
Measuring Global Warming: Global and Hemisphere Mean Temperature Anomalies Predictions Using Sliced Functional Time Series (SFTS) Model
15
作者 Farah Yasmeen 《Open Journal of Applied Sciences》 2019年第5期316-334,共19页
In this study, the sliced functional time series (SFTS) model is applied to the Global, Northern and Southern temperature anomalies. We obtained the combined land-surface air and sea-surface water temperature from God... In this study, the sliced functional time series (SFTS) model is applied to the Global, Northern and Southern temperature anomalies. We obtained the combined land-surface air and sea-surface water temperature from Goddard Institute for Space Studies (GISS), NASA. The data are available for Global mean, Northern Hemisphere mean and Southern Hemisphere means (monthly, quarterly and annual) since 1880 to present (updated through March 2019). We analyze the global surface temperature change, compare alternative analyses, and address the questions about the reality of global warming. We detected the outliers during the last century not only in global temperature series but also in northern and southern hemisphere series. The forecasts for the next twenty years are obtained using SFTS models. These forecasts are compared with ARIMA, Random Walk with drift and Exponential Smoothing State Space (ETS) models. The comparison is made on the basis of root mean square error (RMSE), mean absolute percentage error (MAPE) and the length of prediction intervals. 展开更多
关键词 TEMPERATURE SERIES HEMISPHERIC TEMPERATURE TEMPERATURE Anomalies global Warming Weather Prediction Sliced functionAL Time SERIES Outliers
在线阅读 下载PDF
Global Solutions and Exponential Stability of Stochastic Functional Differential Equations with Infinite Delay
16
作者 徐勇 胡适耕 《Journal of Southwest Jiaotong University(English Edition)》 2010年第1期85-90,共6页
This paper proves that, under the local Lipschitz condition, the stochastic functional differential equations with infinite delay have global solutions without the linear growth condition. Furthermore, the pth moment ... This paper proves that, under the local Lipschitz condition, the stochastic functional differential equations with infinite delay have global solutions without the linear growth condition. Furthermore, the pth moment exponential stability conditions are given. Finally, one example is presented to illustrate our theory. 展开更多
关键词 Stochastic functional differential equation Infinite delay global solution Moment exponential stability
在线阅读 下载PDF
Global Asymptotic Stability and Hopf Bifurcation in a Homogeneous Diffusive Predator-Prey System with Holling Type II Functional Response 被引量:3
17
作者 Shuangte Wang Hengguo Yu +1 位作者 Chuanjun Dai Min Zhao 《Applied Mathematics》 2020年第5期389-406,共18页
In this paper, we considered a homogeneous reaction-diffusion predator-prey system with Holling type II functional response subject to Neumann boundary conditions. Some new sufficient conditions were analytically esta... In this paper, we considered a homogeneous reaction-diffusion predator-prey system with Holling type II functional response subject to Neumann boundary conditions. Some new sufficient conditions were analytically established to ensure that this system has globally asymptotically stable equilibria and Hopf bifurcation surrounding interior equilibrium. In the analysis of Hopf bifurcation, based on the phenomenon of Turing instability and well-done conditions, the system undergoes a Hopf bifurcation and an example incorporating with numerical simulations to support the existence of Hopf bifurcation is presented. We also derived a useful algorithm for determining direction of Hopf bifurcation and stability of bifurcating periodic solutions correspond to j &#8800;0 and j = 0, respectively. Finally, all these theoretical results are expected to be useful in the future study of dynamical complexity of ecological environment. 展开更多
关键词 HOLLING Type II functional Response REACTION-DIFFUSION PREDATOR-PREY System global Stability TURING Instability Hopf Bifurcation
在线阅读 下载PDF
环境约束下我国三大城市群全要素生产率的增长差异研究——基于Global Malmquist-Luenberger指数方法 被引量:15
18
作者 金春雨 王伟强 《上海经济研究》 CSSCI 北大核心 2016年第1期3-12,共10页
该文首先基于方向性距离函数和Global Malmquist-Luenberger指数对2003~2013年京津冀、长三角及珠三角城市群环境约束下的全要素生产率(TFP)变动情况进行了测算与分解,然后从增长源泉、影响因素及经济增长贡献三个方面对京津冀、长三... 该文首先基于方向性距离函数和Global Malmquist-Luenberger指数对2003~2013年京津冀、长三角及珠三角城市群环境约束下的全要素生产率(TFP)变动情况进行了测算与分解,然后从增长源泉、影响因素及经济增长贡献三个方面对京津冀、长三角及珠三角城市群环境TFP变化的差异性展开对比分析。结果表明:京津冀、长三角及珠三角城市群环境TFP总体都呈增长趋势,但京津冀、长三角和珠三角城市群环境TFP增速依次递减,并且技术进步是推动各城市群TFP增长的主要动力,技术效率低下是造成长三角和珠三角城市群TFP增速缓慢的根本原因。人均GRP和资本劳动比对京津冀、长三角以及珠三角城市群环境TFP增长都具有显著的正向影响,但FDI对环境TFP增长的影响系数都显著为负。京津冀和珠三角城市群环境TFP增长对城市经济增长的贡献率略高于长三角城市群,但均不足10%,各城市群的经济发展仍然具有典型的粗放型增长特征。 展开更多
关键词 方向性距离函数 global Malmquist-Luenberger指数 全要素生产率
原文传递
环境与资源约束下城市全要素生产率的测算与分解——基于方向性距离函数和Global Malmquist-Luenberger指数 被引量:1
19
作者 王凯风 《科技与经济》 2017年第6期16-20,共5页
为了在资源与环境约束下研究城市全要素生产率的结构与变化规律,对285个中国城市在2003—2014年间的绿色全要素生产率变化程度进行了测算、分解,其结果表明绿色全要素生产率以年均2.12%的速度增长,其中技术进步和技术效率提升的平均速... 为了在资源与环境约束下研究城市全要素生产率的结构与变化规律,对285个中国城市在2003—2014年间的绿色全要素生产率变化程度进行了测算、分解,其结果表明绿色全要素生产率以年均2.12%的速度增长,其中技术进步和技术效率提升的平均速度分别为1.74%与0.37%。绿色全要素生产率在累积增长率上小于传统全要素生产率,表明中国城市发展过程中的环境与资源代价过高;但也有部分城市能够实现经济增长与环境规制之间的有效协调。城市绿色全要素生产率的累积增长率存在中部>东部>西部的区域差异,技术进步在东部地区绿色全要素生产率增长过程中的贡献最高,而中、西部则相对较多地依赖技术效率改善。 展开更多
关键词 环境 资源 方向性距离函数 全要素生产率 global Malmquist-Luenberger指数
在线阅读 下载PDF
慢性阻塞性肺疾病患者炎症指标及免疫球蛋白与肺功能及肺通气功能障碍严重程度的关系
20
作者 张娇娇 伍亚 +3 位作者 王芳 张硕 张军 李超 《西部医学》 2026年第1期82-86,共5页
目的探讨慢性阻塞性肺疾病(COPD)患者炎症指标及免疫球蛋白与肺功能及肺通气功能障碍严重程度的关系。方法将2020年1月-2024年6月本院收治的107例COPD患者依据肺通气功能障碍严重程度分级分为轻度、中度组58例和中重度、重度、极重度组4... 目的探讨慢性阻塞性肺疾病(COPD)患者炎症指标及免疫球蛋白与肺功能及肺通气功能障碍严重程度的关系。方法将2020年1月-2024年6月本院收治的107例COPD患者依据肺通气功能障碍严重程度分级分为轻度、中度组58例和中重度、重度、极重度组49例,另选取同期于本院体检者102例作为对照组。所有研究对象均在入院后测定炎症指标[C反应蛋白(CRP)、降钙素原(PCT)、白介素-6(IL-6)]、免疫球蛋白(IgM、IgA、IgG)和肺功能指标[第1秒用力呼气容量(FEV1)、用力肺活量(FVC)、FEV1/FVC]。采用Pearson相关性分析CRP、PCT、IL-6、IgM、IgA、IgG与FEV1、FVC、FEV1/FVC的相关性,以Spearman相关性分析CRP、PCT、IL-6、IgM、IgA、IgG与肺通气功能障碍严重程度分级的关系。结果研究组的CRP、PCT、IL-6水平高于对照组,IgA、IgG、FEV1、FVC、FEV1/FVC低于对照组(P<0.05)。Pearson相关性分析显示,COPD患者CRP、PCT、IL-6水平与FEV1、FVC、FEV1/FVC呈负相关(r=-0.482,-0.476,-0.374;-0.468,-0.453,-0.363;-0.376,-0.364,-0.345,P<0.05);IgA、IgG与FEV1、FVC、FEV1/FVC呈正相关(r=0.403,0.412,0.373;0.345,0.327,0.308,P<0.05)。中重度、重度、极重度组患者的CRP、PCT、IL-6水平高于轻度、中度组,IgA、IgG低于轻度、中度组(P<0.05);不同肺通气功能障碍严重程度分级患者IgM间比较差异不明显(P>0.05)。Spearman相关性分析,CRP、PCT、IL-6水平与肺通气功能障碍严重程度分级呈正相关(r=0.518,0.513,0.496,P<0.05);IgA、IgG与肺通气功能障碍严重程度分级呈负相关(r=-0.293,-0.285,P<0.05)。结论COPD患者炎症指标及免疫球蛋白与肺功能及肺通气功能障碍严重程度分级密切相关,临床可通过早期测定炎症指标及免疫球蛋白水平为COPD患者肺功能及病情严重程度的评估提供一定的参考价值。 展开更多
关键词 慢性阻塞性肺疾病 炎症指标 免疫球蛋白 肺功能 COPD全球倡议分级 相关性
暂未订购
上一页 1 2 126 下一页 到第
使用帮助 返回顶部