特别声明

从技术进步的角度出发对增长极理论模型化进行了探索,给出了运用增长极模式的一个必要条件——增长极的选择规模限度,说明了新增投资比例与采用增长极模式的预期开发效果(扩散效应)、增长极的极化效应强度以及极化效应完成的时间长短之间的关系,并实证探讨了增长极理论在西部开发中应用的可行性。     

Manufacturing's Roel in Innovation Diffusion and Technological Substitution

Successful innovation management depends upon both, the intrinsic attributes of the new product to be marketed and the firm's internal performance like cost management, timely delivery and quality assurance. The impact of these latter aspects is frequently neglected in the design of models for supporting decision making in innovative firms.A model is outlined to study the market response of different manufacturing policies for innovative goods. It allows e.g. the evaluation of an aggressive strategy with large production capacities from the outset, or a more tentative behavior to. avoid the pressures stemming from high fixed cost and the risks of eventually idle capacity.     

含时滞的单种群反馈控制扩散模型解的渐近行为

本文通过构造 Liapunov 泛函并结合 Smoller 不变区域理论和不等式估计方法,对含时滞的单种群反馈控制扩散模型解的渐近行为进行了讨论,获得了解的整体存在性、有界性及解的一致收敛性的若干充分条件.     

Some aspects of modern population mathematics

The purpose of this paper is to survey a number of the technical tools and models that have found use in the study of human and other populations, and to indicate some problems of current interest. These tools and models are varied: integral equations, nonlinear oscillations, differential geometry, dynamical systems, nonlinear operations, bifurcation theory, semigroup theory, martingale theory, Markov processes, diffusion processes, branching processes, ergodic theory, prediction theory and state-space models. A fairly extensive bibliography is provided. Also an Appendix has been added describing the analysis of a classical entomological data set.     

Geostochastic calculus

A stochastic calculus for a family of continuous measure-valued Markov processes is developed. Such processes arise naturally in the construction of stochastic models of spatially distributed populations. The stochastic calculus is a tool whereby a class of density-dependent models can be studied in terms of the multiplicative measure diffusion process. In this paper the stochastic integral is introduced in the space-time setting and a Cameron-Martin-Girsanov theorem is established.     

区域创新系统中知识扩散国外研究进展及未来展望

从区域创新系统知识扩散的影响因素、扩散途径、扩散特点入手,对1992年至2013年间国外区域创新系统有关知识扩散的研究进行了文献回顾,探讨了区域创新网络建设、区域创新系统政策研究等对知识扩散的作用,指出创新网络对知识扩散、政策工具运用对区域创新系统建设方面是西方学者关注重点,同时根据相关研究,提出区域创新系统中关于知识扩散方面未来的研究侧重点。     

索尔仁尼琴及其《古拉格群岛》的创作风格

作为20世纪引人注目的俄侨作家,索尔仁尼琴的作品以及传奇的一生越来越受到俄罗斯人民和世界各图文学家的关注,作家本人和他的作品因其复杂的经历而被赋予了神话般的色彩.这位富有人道主义精神的唯灵主义作家,对道德和真理的探求体现出俄罗斯文学的悠久传统,并将这种传统应用于小说<古拉格群岛>的创作中.作家在作品中以"写真实"的写作手法,以发散性的风格为读者展示出了一个鲜为人知的世界.     

产业共性技术扩散中政府作用最优力度分析——基于变换的Bass模型

基于一定理论假设将Bass模型中技术扩散的内部影响因素和外部影响因素分别与市场作用和政府作用对应起来,并着眼于政府作用对市场作用的“挤出”效应建立起政府作用与市场作用之间的函数关系,以此来对Bass模型进行变换,使其能刻画政府作用对产业共性技术扩散速度和时间路径的影响。基于变换的Bass模型,以最大化技术扩散速度为目标构建最优化问题以求得政府作用最优力度,由最优化问题可知政府作用对市场作用的“挤出”效应越大,最优政府作用力度就应该越小。还基于相关数据进行了数值模拟分析,并且验证了模型的有效性。研究认为:由于存在政府干预对市场作用的“挤出”效应,在促进产业共性技术扩散中需要把握最优的干预力度即政府作用最优力度,在量化政府作用和市场作用的基础上,求解出来的政府作用最优力度系数可为政府有效和适当干预技术扩散提供理论上的一个尺量。     

Locking the Wiener Process to its Level-Crossing Time

We consider the specific transformation of a Wiener process {X(t), t ≥ 0} in the presence of an absorbing barrier a that results when this process is “time-locked” with respect to its first passage time T _a through a criterion level a, and the evolution of X(t) is considered backwards (retrospectively) from T _a . Formally, we study the random variables defined by Y(t) ≡ X(T _a  ? t) and derive explicit results for their density and mean, and also for their asymptotic forms. We discuss how our results can aid interpretations of time series “response-locked” to their times of crossing a criterion level.     

Seroadaptive Strategies of Vancouver Gay and Bisexual Men in a Treatment as Prevention Environment

British Columbia’s treatment as prevention policy has provided free access to highly active antiretroviral therapy (HAART) to all HIV-positive provincial residents since 1996. One outcome is an increase in HIV-positive gay and bisexual men (GBM) with suppressed viral loads. Previous cross-sectional analyses indicated that some Vancouver GBM now recognize condomless anal sex with men on HAART who report a suppressed viral load as a seroadaptive strategy. To test the hypothesis that this new strategy, termed viral load sorting (VLS), is recognized and used among by GBM in the Momentum Health Study, we analyzed longitudinal data for HIV-negative/unknown (n = 556) and HIV-positive (n = 218) serostatus participants. Analyses indicated that both groups reported VLS, and that serostatus and Treatment Optimism Scale scores were significant determinants in frequency and use. Results exemplify the medicalization of sex and Rogers’ Diffusion Of Preventative Innovations Model, and they have important implications for HIV research and GBM sexual decision-making.