密度分布非均匀的反馈控制Logistic单种群模型平衡态的稳定性

本文对种群密度在非均匀分布情形下,考虑了具反馈控制的滞后 Logistic 生态模型平衡位置的稳定性;分别给出了在常时滞和弱连续时滞以及强连续时滞情况下的稳定性条件;其结果是对 Gopalsamy 在密度均匀分布情形下相应结果的推广.     

经济系统混沌研究方法论

根据混沌研究的一般方法 ,结合经济系统实际 ,提出经济系统混沌研究所应遵循的一般步骤。所提出的理论、方法有广泛的实际应用价值。     

Semi-parametric estimation of ROC curves based on binomial regression modelling

This paper presents a method of estimating a receiver operating characteristic (ROC) curve when the underlying diagnostic variable X is continuous and fully observed. The new method is based on modelling the probability of response given X , rather than the distribution of X given response. The method offers advantages in modelling flexibility and computational simplicity. The resulting ROC curve estimates are semi-parametric and can, in principle, take an infinite variety of shapes. Moreover, model selection can be based on standard methods within the binomial regression framework. Statistical accuracy of the curve estimate is provided by a simply implemented bootstrap approach.     

信息产业对经济增长贡献的计量分析

文章试图对信息产业对经济增长的贡献作一定量分析。为此,首先将国内部门分为信息产业与非信息产业两大部门,并以这两部门的生产函数为基础,推导出最终的计量模型,然后根据湖北省的有关数据对模型进行回归分析。分析的结果表明,信息产业对经济增长的综合的边际产出贡献很高,从而说明对信息产业应继续加大投入,引导和扶持信息产业的发展,以促进整个湖北省经济持续、高速、稳定增长。     

中国经济法经济学基础的反思与前瞻

中国经济法经济学基础有两种潮流,其主流经过了三个阶段两次变化。“主流”将市场失败理论作为支点,把市场缺陷作为问题而遮蔽了真正的“中国问题”。试图摆脱困境的“支流”却进一步误导人们要不断向西方学习和创新。执着地寻求西方经济学为理论支援且对中国现实问题不太关注乃是因为学者们受着“现代化框架”的支配。确立坚实的中国经济法经济学理论基础,只能以“当下中国问题”为依据,以古今中外经济理论为资源并实现其与中国现实的契合。     

转型期实现内外均衡的政策搭配研究

中国在入世后的10年左右 ,正处于转型经济中。应该通过调节社会总需求、社会总供给等政策工具 ,实现合理搭配 ,以达到中国宏观经济的内外均衡     

On the asymptotic normality of the L1- and L2-errors in histogram density estimation

The L₁ and L₂-errors of the histogram estimate of a density f from a sample X₁,X₂,…,Xn using a cubic partition are shown to be asymptotically normal without any unnecessary conditions imposed on the density f. The asymptotic variances are shown to depend on f only through the corresponding norm of f. From this follows the asymptotic null distribution of a goodness-of-fit test based on the total variation distance, introduced by Györfi and van der Meulen (1991). This note uses the idea of partial inversion for obtaining characteristic functions of conditional distributions, which goes back at least to Bartlett (1938).     

近代河南集市研究再思考

近代集市的发展不仅表现为数量方面的增加,也有集市数量不变而集市承载量增加的情况;考察集市分布密度以耕地面积为基础更有可比性,而且开市率的高低主要是人们传统习惯、人口规模、集市密度、商品化程度、经济发展状况等因素综合作用的结果,其中传统习惯对开市率的影响较大。     

经济发展、资源功能与中国的配置绩效

经济发展理论高度重视各种资源等劳动对象的开发利用。西方经济学的信仰者由于自身存在的认识论缺陷，难以科学认识劳动对象与经济发展的内在关系，进而也难以科学论述资源在发展理论及其模型中的作用和地位。因此，必须遵循马克思的方法论，从理论为实际的反映入手，建立科学的分析模型，以此指导中国经济发展方式的转变，建立生态与经济相协调的可持续发展的资源及能源支撑体系，调整、优化资源及能源的供给与需求结构。     

Data skeletons: simultaneous estimation of multiple quantiles for massive streaming datasets with applications to density estimation

We consider the problem of density estimation when the data is in the form of a continuous stream with no fixed length. In this setting, implementations of the usual methods of density estimation such as kernel density estimation are problematic. We propose a method of density estimation for massive datasets that is based upon taking the derivative of a smooth curve that has been fit through a set of quantile estimates. To achieve this, a low-storage, single-pass, sequential method is proposed for simultaneous estimation of multiple quantiles for massive datasets that form the basis of this method of density estimation. For comparison, we also consider a sequential kernel density estimator. The proposed methods are shown through simulation study to perform well and to have several distinct advantages over existing methods.