Estimation of Metabolic Rate Constants in PBPK‐Models from Liver Slice Experiments: What Are the Experimental Needs?

A mechanistic model is presented describing the clearance of a compound in a precision-cut liver slice that is incubated in a culture medium. The problem of estimating metabolic rate constants in PBPK models from liver slice experiments is discussed using identifiability analysis. From the identifiability problem analysis, it appears that in addition to the clearance, the compound's free fraction in the slice and the diffusion rate of the exchange of the compound between culture medium and liver slice should be identified. In addition, knowledge of the culture medium volume, the slice volume, the compound's free fraction, and octanol-water-based partition between medium and slice is presupposed. The formal solution for identification is discussed from the perspective of experimental practice. A formally necessary condition for identification is the sampling of parent compound in liver slice or culture medium. However, due to experimental limitations and errors, sampling the parent compound in the slice together with additional sampling of metabolite pooled from the medium and the slice is required for identification in practice. Moreover, it appears that identification results are unreliable when the value of the intrinsic clearance exceeds the value of the diffusion coefficient, a condition to be verified a posteriori.     

MAS环境下实现Agent交互协作的关键技术

讨论了MAS环境下实现Agent交互协作的关键性问题。在分析Agent协同设计目标的基础上,将遗传算法应用于子任务的调度,提高了Agent协同工作的效率。应用Agent的通信语言建立了一个基于知识查询与操纵语言的Agent通信模型,通过引入Agent位置追踪和Agent消息缓存机制解决了Agent移动过程中遇到的位置追踪和通信失效问题。     

简论知识经济时代创新人才的继续教育培训模式

随着以科技创新为主要特征的知识经济时代的来临 ,继续教育要适应现代社会发展的需要 ,培养具有创新意识、创新能力的高素质人才 ,必须在教育观念、培养目标、教学内容、教学方法、教学手段、师资队伍等方面进行改革和创新 ,探索出适应知识经济时代需要的创新人才继续教育培训模式。     

顾客价值创新:战略分析的基点

传统的战略分析是以竞争为基点的。其目的是如何比竞争对手做得更好。在这种思维指导下 ,企业经营往往产生竞争激烈、市场不敏感、反应性行为、缺乏创新等后果。在复杂多变的环境中 ,战略分析应转移到顾客价值创新上来。顾客价值创新战略通过为顾客提供完全新型或得到重大改进的价值而使企业经营与竞争无关。顾客价值创新战略与竞争基点战略在战略导向、对竞争的认知及态度、企业本身实力的认识等具有明显不同的特征 ;进行顾客价值创新可以按照顾客价值创新循环机制进行 ,这一循环机制以顾客消费流程分析为起点 ,由创新机会认别、资源需求分析及价值创新实施等环节构成。     

一般Gauss－Markov模型下一般可估函数的线性充分性和线性完全性

发展了Ｂａｋｓａｌａｒｙ和Ｄｒｙｇａｓ提出的一般Ｇａｕｓｓ－Ｍａｒｋｏｖ模型中线性充分性、最小充分性和完全性的概念，用Ｒａｏ的最小二乘统一理论，给出了这些概念的刻划定理。     

基于Briefcase模型的MIS系统的设计与实现

介绍了ADO下Briefcase软件模型的原理 ,并在Delphi 5 .5中利用其ADOExpress组件进行设计和实现了Briefcase软件模型的分布式MIS系统的应用 ,该模型的应用为分布式数据库软件的稳定性和强健性提供了有力保障     

Robust confidence interval for a residual standard deviation

The residual standard deviation of a general linear model provides information about predictive accuracy that is not revealed by the multiple correlation or regression coefficients. The classic confidence interval for a residual standard deviation is hypersensitive to minor violations of the normality assumption and its robustness does not improve with increasing sample size. An approximate confidence interval for the residual standard deviation is proposed and shown to be robust to moderate violations of the normality assumption with robustness to extreme non-normality that improves with increasing sample size.     

Uncertainty Analysis for Computer Model Projections of Hurricane Losses

Projecting losses associated with hurricanes is a complex and difficult undertaking that is wrought with uncertainties. Hurricane Charley, which struck southwest Florida on August 13, 2004, illustrates the uncertainty of forecasting damages from these storms. Due to shifts in the track and the rapid intensification of the storm, real-time estimates grew from 2 to 3 billion dollars in losses late on August 12 to a peak of 50 billion dollars for a brief time as the storm appeared to be headed for the Tampa Bay area. The storm hit the resort areas of Charlotte Harbor near Punta Gorda and then went on to Orlando in the central part of the state, with early poststorm estimates converging on a damage estimate in the 28 to 31 billion dollars range. Comparable damage to central Florida had not been seen since Hurricane Donna in 1960. The Florida Commission on Hurricane Loss Projection Methodology (FCHLPM) has recognized the role of computer models in projecting losses from hurricanes. The FCHLPM established a professional team to perform onsite (confidential) audits of computer models developed by several different companies in the United States that seek to have their models approved for use in insurance rate filings in Florida. The team's members represent the fields of actuarial science, computer science, meteorology, statistics, and wind and structural engineering. An important part of the auditing process requires uncertainty and sensitivity analyses to be performed with the applicant's proprietary model. To influence future such analyses, an uncertainty and sensitivity analysis has been completed for loss projections arising from use of a Holland B parameter hurricane wind field model. Uncertainty analysis quantifies the expected percentage reduction in the uncertainty of wind speed and loss that is attributable to each of the input variables.     

论政治语言的结构

分析和研究政治语言的系统结构及结构要素之间的相互关系 ,是研究政治语言的重要内容 ,有利于更好地认识和把握政治语言。政治语言结构是一种特殊的层级系统 ,其要素包括符号、符号系统、符码、文本、语境和话语。政治语言结构的要素之间相互作用、相互关联 ,共同构成了政治语言的系统 ,并以其特有的方式表达政治意义 ,服务于政治活动     

两相交流伺服电机动态性能的研究

对于两相交流电机的速度伺服系统,分析在幅值控制时系统的机械特性与调节特性,提出了影响两相交流伺服电机动态性能的因素是系统的机械时间常数及增益系数的变化。为了防止因机械时间常数及增益系数的变化而引起的动态特性变差,采用一种简易跟随模型参考自适应控制方法,通过模型与自适应机构的调节作用,改善两相交流伺服电机系统的动态特性和控制精度。计算机仿真结果表明,电机的动态持性良好。