Nonlinear mixed effects modelling for estimation of steady state attainment

Assessment of the time needed to attain steady state is a key pharmacokinetic objective during drug development. Traditional approaches for assessing steady state include ANOVA‐based methods for comparing mean plasma concentration values from each sampling day, with either a difference or equivalence test. However, hypothesis‐testing approaches are ill suited for assessment of steady state. This paper presents a nonlinear mixed effects modelling approach for estimation of steady state attainment, based on fitting a simple nonlinear mixed model to observed trough plasma concentrations. The simple nonlinear mixed model is developed and proposed for use under certain pharmacokinetic assumptions. The nonlinear mixed modelling estimation approach is described and illustrated by application to trough data from a multiple dose trial in healthy subjects. The performance of the nonlinear mixed modelling approach is compared to ANOVA‐based approaches by means of simulation techniques. Copyright © 2005 John Wiley & Sons, Ltd.     

一类具有扩散的互惠系统的存在性与全局渐近性

本应用上下解方法研究了其一具有饱和作用项的两种群互惠系统，得到了其正平衡态解和各类半平凡解存在和稳定的条件，同时也给出了有关动态解的某些渐近性结果。     

Cost‐efficient higher‐order crossover designs for two‐treatment clinical trials

Higher‐order crossover designs have drawn considerable attention in clinical trials, because of their ability to test direct treatment effects in the presence of carry‐over effects. The important question, when applying higher‐order crossover designs in practice, is how to choose a design with both statistical and cost efficiencies from various alternatives. In this paper, we propose a general cost function and compare five statistically optimal or near‐optimal designs with this cost function for a two‐treatment study under different carry‐over models. Based on our study, to achieve both statistical and cost efficiencies, a four‐period, four‐sequence crossover design is generally recommended under the simple carry‐over or no carry‐over models, and a three‐period, two‐sequence crossover design is generally recommended under the steady‐state carry‐over models. Copyright © 2005 John Wiley & Sons, Ltd.     

调控劳动工时 创建稳态社会

本文试图通过界定和分析“实现劳动供求均衡的劳动工时”这一概念,指出在工资水平完全由市场调节的情况下,政府的主要任务就是在法律的框架内加强对劳动工时的调控,从而在根本上解决失业以及由之而来的一系列社会问题,以期实现稳态社会。     

博弈—升值压力下的人民币汇率政策选择

自1997年金融危机爆发后,人民币汇率政策的制定经历了两个相对重要的时期:一个是亚洲金融危机时期;一个是自2002年底以来全球面临通货紧缩压力之时.这两次人民币汇率政策选择过程,也是中国货币当局与美国、日本等经济大国的国际博弈过程.本文通过对上述两个时期的博弈分析,建立了相应的数学抽象分析模型,探索人民币汇率制度的改革方向.     

我国内外部均衡关系初探

在经济开放的市场经济国家 ,内外部均衡之间既有相互协调的一面 ,又有互相冲突的一面。改革开放以后 ,我国内外部均衡之间的这种关系也开始逐步显现。同时 ,由于我国目前的市场经济建设还不成熟 ,经济体制的某些方面改革还没有到位 ,因而内外部均衡之间的关系又呈现出与一般市场经济国家不同的特征。我国内外部均衡的这种关系对我们制定内外部均衡政策有一定的启示     

桥面物理除冰雪加热功率与环境因素关系分析

为解决化学融雪剂腐蚀桥梁结构和污染环境的问题,提出桥面敷设加热电缆方式除冰雪技术方案,以30 m预应力混凝土T梁桥、沥青混凝土桥面为分析对象,进行了瞬态热分析和稳态热分析,系统研究了在桥面加热升温和稳态融雪节段加热功率与环境温度和环境风速的关系。经分析可知桥面加热过程可分为滞后、升温和稳态三个阶段,得出了一些有意义的结论,可为桥面敷设加热电缆除冰雪设计提供理论参考。     

论稳态语境与动态语境的关系

从语境因素的特点看，语境有稳态语境和动态语境的不同。动态语境和稳态语境是由语境因素的可变性和稳定性决定的。稳态语境和动态语境是辩证统一的关系：稳态语境可以通过动态语境得到展示；动态语境可以在稳态语境中得到聚焦。     

输气管道稳态计算公式改进研究

输气管道工艺计算稳态公式在管道设计和管理过程中起着十分重要的作用。针对目前我国有关规范中常用稳态计算公式忽略了流速变化所带来的影响，适用范围受到限制的实际，根据天然气     

农民流动的现实图景与前景展望——以M村农民流动为例

农民流动现象是三农问题的重要观测点,通过对个案的调查研究,探寻农民流动的历史和现实原因,描绘倒陀螺式流动模式及其冲蚀作用下的农村变迁,指出改变当前低质量的农民流动亟待制度改革突破传统利益格局,实现理想状态的农民流动。