合成氨系统优化的一类新方法

本文介绍一类新的优化方法及其在合成氨系统上应用的例子。该大系统分解-协调方法可方便地处理高阶系统。由计算机仿真对给定值进行调整,经实验验证,结果满意。文中并对在线计算机控制方案进行了探讨。     

论三峡地区板楯蛮的赋税缴纳与社会动荡

板楯蛮原是三峡地区一个古老的土著民族，其族名有三：或板楯蛮、或蜜、或白虎复夷。该民族因多种原因或迁徙北方、或南移湘西、或滞留三峡地区。在先秦至西汉时期，板楯蛮因屡建战功，朝廷对之轻徭薄赋；秦惠王时，因“白虎为害”事件，导致巴人内部的分裂；东汉至魏晋六朝，因朝廷加重赋税，又导致板楯蛮无数次“反叛”朝廷，最终使板楯蛮地区社会动荡，生产停滞，经济萧条，人民流徙甚至死亡。     

Forecasting European GNP data through common factor models and other procedures

In this paper we present an extensive study of annual GNP data for five European countries. We look for intercountry dependence and analyse how the different economies interact, using several univariate ARIMA and unobserved components models and a multivariate model for the GNP incorporating all the common information among the variables. We use a dynamic factor model to take account of the common dynamic structure of the variables. This common dynamic structure can be non‐stationary (i.e. common trends) or stationary (i.e. common cycles). Comparisons of the models are made in terms of the root mean square error (RMSE) for one‐step‐ahead forecasts. For this particular group of European countries, the factor model outperforms the remaining ones. Copyright © 2002 John Wiley & Sons, Ltd.     

机电系统全寿命模拟研究

重大机电产品可靠性研究具有广阔的工程背景和较高的经济效益，但其可靠性试验常造成资源浪费和环境污染，为使此类系统可靠性研究可持续发展，文章中介绍了以小子样系统为理论框架的数值模拟可采用的有效方法以及工程实例验证。     

平面铰链四杆机构的数学模型

本文提出采用一种基本数学模型，辅以若干变换数学模型，再考虑两种可能模式 之间的相互转变的方法，比较简单而系统地解决了众多类型的平面铰链四杆机构位置 分析的通用数学模型问题，为其动态运动过程仿真应用软件的编制提供了合理的理论 依据。     

非线性系统基于T-S模型的H∞控制

将非线性系统用 T-S模糊动态模型描述 ,并将全局模糊系统模型表示成不确定系统形式 .采用鲁棒 H∞ 控制策略 ,设计出使全局模糊系统模型渐近稳定的控制器 ,并以一级倒立摆的模糊控制器设计实例 ,证明了方案的简洁有效     

水面舰艇综合反潜仿真系统设计研究

水面舰艇综合反潜仿真系统可实现在攻防对抗条件下反潜作战过程的仿真,用于研究反潜作战方法,验证新型武器系统的作战性能,论证各种反潜武器装备的作战需求。本文分析了水面舰艇综合反潜仿真系统的功能、组成和特点,并探讨了系统基于HLA的体系结构、仿真模型及有关的关键技术。     

Volatility forecasting for risk management

Recent research has suggested that forecast evaluation on the basis of standard statistical loss functions could prefer models which are sub‐optimal when used in a practical setting. This paper explores a number of statistical models for predicting the daily volatility of several key UK financial time series. The out‐of‐sample forecasting performance of various linear and GARCH‐type models of volatility are compared with forecasts derived from a multivariate approach. The forecasts are evaluated using traditional metrics, such as mean squared error, and also by how adequately they perform in a modern risk management setting. We find that the relative accuracies of the various methods are highly sensitive to the measure used to evaluate them. Such results have implications for any econometric time series forecasts which are subsequently employed in financial decision making. Copyright © 2002 John Wiley & Sons, Ltd.     

坡面土壤水蚀建模方法比较

首先阐述了坡面土壤水蚀建模的必要性.考虑到原有水蚀模型类型的不足,对当前水蚀模型按解题方法重新归为形式逻辑计算模型及辩证逻辑计算模型两类.其中,形式逻辑计算模型又分为经验模型、半概念半经验模型、半过程半经验模型以及理论模型4类.结合实例阐述这几类模型的主要特性及相关关系.