关于Bellman問題

本文首先研究了常时滞线性方程与变时滞线性方程解之间的一致性问题,然后作为特殊情况,解决了Bellman于1965年提出的一个问题。     

怎样評价一个专家系统

本文首先介绍了专家系统,然后着重介绍了国外评价专家系统的准则。它包括基本特性的估计、开发环境、学习和使用性、成本以及怎样得到支持等,最后将举例说明怎样用这些准则来评价一个实际的专家系统。     

塑料注射机节能问题的研究与探讨

本文针对 XS—ZY—125型塑料注射成型机,分析了现行通用的双联泵供油液压系统耗能大的原因。介绍了压力流量补偿负荷传感液压系统在注射机上应用的基本原理。通过应用上述两种液压系统分别驱动同一台注射机的生产运行对比试验和能耗测试分析,证明压力流量补偿负荷传感液压系统具有十分显著的节能效果。通过经济效益估算分析,指出进一步开发压力流量补偿负荷传感液压系统在注射机上的应用,不仅具有十分显著的经济效益,而且具有很大的社会效益。     

离心式叶轮机任意旋成面栅后区长度处理

文章揭示了叶轮栅后区长度L_3太长时,会使栅后区出气角β_2无法选择而造成无解的事实;表明在β_2变化的适当范围内,叶型后缘两侧速度差△Λ与β_2之间呈线性关系,而且该线性变化范围随L_3的增长而缩小;获得了随L_3作线性变化的规律。文章最后提出了离心式叶轮机任意旋成面叶栅流场的简单求解方法。     

一种实用自适应PID控制器

本文介绍了一种实用自适应PID控制器,它是以MCS-51系列单片微机为核心,采用PID控制规律结合参数辨识的控制算法,实现了PID参数完全在线自动整定。该控制器适用于被控制对象未知或慢时变的场合,既可替代常规PID控制器,也可作为分布式系统的低级智能控制器。     

回旋管及回旋潘尼管的动力学理论

本文发展了目前回旋管的动力学理论。用动力学方法,描述了回旋潘尼管的不稳定性机理,求解了偶极电流。这样,本文提出的理论,不仅可以更为精确地描写回旋管,而且可以描写新近出现的回旋潘尼管。     

巨灾风险对非寿险总产出核算影响的研究

 随着中国保险业的迅猛发展,保险核算在一国经济中变得越来越重要。越来越频繁发生的自然灾害、恐怖袭击等造成的巨大损失对联合国国民账户体系(93SNA)推荐的非寿险服务产出核算产生重大冲击,严格按照93SNA算法计算保险服务价值会导致荒谬的结果。首先本文介绍了国际上几种主要的改进方法,对每种方法的优缺点进行了深入分析。这些方法对我国改善保险核算,尤其是非寿险服务产出核算具有重要的启示意义。其次运用广东省（不含深圳）保险业的数据和期望法对06、07年的总产出进行计算,构建预测模型,并比较分析计算的结果。最后,本文提出对改进我国保险核算的建议。     

青岛一套表的实践与经验

 企业统计一套表一直是统计制度方法改革和实践中的焦点问题。本文通过对青岛市统计局企业一套表制度实施情况的案例分析,系统界定了企业一套表的概念和内涵,全面展现了企业一套表的运作过程,客观分析了制约企业一套表实施的主要原因,并提出了在现阶段实施企业统计一套表的条件和要求。     

A Bayesian discovery procedure

Summary.  We discuss a Bayesian discovery procedure for multiple-comparison problems. We show that, under a coherent decision theoretic framework, a loss function combining true positive and false positive counts leads to a decision rule that is based on a threshold of the posterior probability of the alternative. Under a semiparametric model for the data, we show that the Bayes rule can be approximated by the optimal discovery procedure, which was recently introduced by Storey. Improving the approximation leads us to a Bayesian discovery procedure, which exploits the multiple shrinkage in clusters that are implied by the assumed non-parametric model. We compare the Bayesian discovery procedure and the optimal discovery procedure estimates in a simple simulation study and in an assessment of differential gene expression based on microarray data from tumour samples. We extend the setting of the optimal discovery procedure by discussing modifications of the loss function that lead to different single-thresholding statistics. Finally, we provide an application of the previous arguments to dependent (spatial) data.     

Accelerated hazards mixture cure model

We propose a new cure model for survival data with a surviving or cure fraction. The new model is a mixture cure model where the covariate effects on the proportion of cure and the distribution of the failure time of uncured patients are separately modeled. Unlike the existing mixture cure models, the new model allows covariate effects on the failure time distribution of uncured patients to be negligible at time zero and to increase as time goes by. Such a model is particularly useful in some cancer treatments when the treat effect increases gradually from zero, and the existing models usually cannot handle this situation properly. We develop a rank based semiparametric estimation method to obtain the maximum likelihood estimates of the parameters in the model. We compare it with existing models and methods via a simulation study, and apply the model to a breast cancer data set. The numerical studies show that the new model provides a useful addition to the cure model literature.