交通信息条件下道路和停车选择SUE模型及算法

考虑交通信息系统(advanced traveler information system,ATIS)对出行者道路和停车选择行为的影响,并将出行者分成两类:一类出行者使用ATIS,另一类不使用ATIS.在此基础上,构造了一个基于概率的随机用户均衡模型来描述ATIS条件下的道路和停车选择问题,并给出了相应的求解算法.最后,通过一个算例分析了模型及算法的使用效果.     

多个不确定性因素下跨国公司投资策略

利用实物期权方法,在汇率、国内外生产成本和产品价格均不确定的情况下,把跨国企业迁移生产和销售的空间决策柔性(spatial decision flexibility)模型为交换期权,分别给出了迁移生产的最优下界和迁移销售的最优上界、及其迁移决策规则,并讨论了关键参数对迁移决策规则的影响。最后,给出应用迁移生产和销售决策规则的数值模拟算例,体现了本文给出的决策规则在实际应用中具有可操作性。     

Adapting by calibration the sample size of a phase III trial on the basis of phase II data

The problem of estimating the sample size for a phase III trial on the basis of existing phase II data is considered, where data from phase II cannot be combined with those of the new phase III trial. Focus is on the test for comparing the means of two independent samples. A launching criterion is adopted in order to evaluate the relevance of phase II results: phase III is run if the effect size estimate is higher than a threshold of clinical importance. The variability in sample size estimation is taken into consideration. Then, the frequentist conservative strategies with a fixed amount of conservativeness and Bayesian strategies are compared. A new conservative strategy is introduced and is based on the calibration of the optimal amount of conservativeness – calibrated optimal strategy (COS). To evaluate the results we compute the Overall Power (OP) of the different strategies, as well as the mean and the MSE of sample size estimators. Bayesian strategies have poor characteristics since they show a very high mean and/or MSE of sample size estimators. COS clearly performs better than the other conservative strategies. Indeed, the OP of COS is, on average, the closest to the desired level; it is also the highest. COS sample size is also the closest to the ideal phase III sample size M_I, showing averages and MSEs lower than those of the other strategies. Costs and experimental times are therefore considerably reduced and standardized. However, if the ideal sample size M_I is to be estimated the phase II sample size n should be around the ideal phase III sample size, i.e. n?2M_I/3. Copyright © 2010 John Wiley & Sons, Ltd.     

Constructing optimal designs for fitting pharmacokinetic models

We consider some computational issues that arise when searching for optimal designs for pharmacokinetic (PK) studies. Special factors that distinguish these are (i) repeated observations are taken from each subject and the observations are usually described by a nonlinear mixed model (NLMM), (ii) design criteria depend on the model fitting procedure, (iii) in addition to providing efficient parameter estimates, the design must also permit model checking, (iv) in practice there are several design constraints, (v) the design criteria are computationally expensive to evaluate and often numerical integration is needed and finally (vi) local optimisation procedures may fail to converge or get trapped at local optima.We review current optimal design algorithms and explore the possibility of using global optimisation procedures. We use these latter procedures to find some optimal designs.For multi-purpose designs we suggest two surrogate design criteria for model checking and illustrate their use.     

地方工科院校环境艺术设计专业课程体系的优化研究

根据社会的需求及环境艺术设计学科的特点，利用地方工科院校的优势，研究适合地方工科院校环境艺术设计专业方向人才培养的课程体系，优化教学内容及实践教学手段，通过实践探索，完善并总结出切实可行的人才培养方案。     

A Comparison of Three-level Orthogonal Arrays in the Presence of a Possible Correlation in Observations

When we want to compare two designs we usually assume the standard linear model with uncorrelated observations. In this paper we use the comparison method proposed by Ghosh & Shen (2006) to compare three level orthogonal arrays with 18, 27 and 36 runs under a possible presence of correlation in observations.     

多市场非均衡模型的调控规律研究

联系经济运行的现实不难发现，较之均衡状态，非均衡状态的出现在时间上更经常，在空间上更广泛，因此，要对非均衡程度予以重视，并加以调控。本文以供求相等作为理想状态，运用无约束最优控制理论推导出用一般函数形式表示的微观及宏观多市场的非均衡调控律，同时提出多种调控手段综合运用的一般原则。     

碳限额与交易政策下供应链低碳技术投资时机研究

在碳排放权限额与交易政策环境下, 碳排放权交易价格的不确定性对供应链企业选择低碳技术投资时机具有重要的影响。利用实物期权理论评估碳交易价格不确定情况下供应链低碳技术投资具有的期权价值, 建立供应链低碳技术投资时机决策的基本模型, 在此基础上, 构建考虑供应链内部合作的低碳技术投资博弈模型, 重点讨论供应链上下游企业在对投资时机与转移支付比例进行决策的均衡策略。基于上述模型, 通过数值算例进一步分析低碳技术投资时机的影响因素。研究结果表明:碳减排率水平、碳价波动率、企业间转移支付比例等因素会对低碳投资门槛产生影响, 供应链企业应综合评价碳价波动下低碳技术投资的期权价值, 合理选择投资时机与转移支付比例的最佳平衡点, 实现经济效益和低碳减排的双重目标, 并保障供应链协调与投资优化。     

关联理论与广告效果

广告作为一种应用语言 ,不仅具有很高的商业价值和欣赏价值 ,同时它的语言研究价值也日益受到人们的重视。从认知语用学的角度出发 ,依据关联理论 ,对广告的认知推理过程加以分折 ,并结合语境效果和最佳关联的产生条件 ,探讨信息关联对广告效果的影响     

营造一个理想的人居环境

2 1世纪是优化人类居住环境的时代 ,世界各发达国家和地区都十分重视营造最佳人居环境。社会主义中国如何营造最佳人居环境 ?本文提出应用“山水城市”的理论 ,指导城市设计。以国际花园城市杭州为例 ,有得天独厚的自然、历史条件 ,可以营造最佳人居“新天堂”。