具有两类修复设备可修系统解的最优控制问题

用Banach空间理论,以泛数指标函数作为衡量系统可控的标准,讨论了可修复系统最优控制问题．     

大豆害虫的研究概况

根据近年来国内外对大豆害虫的研究现状，从大豆害虫种类、主要害虫的生物学及生态学特征、预测预报、种群结构变化及综合防治5个方面，对大豆害虫的研究概况进行综述，并对未来的发展趋势加以展望。     

The MAP test for multimodality

We introduce a test for detecting multimodality in distributions based on minimal constrained spanning trees. We define a Minimal Ascending Path Spanning Tree (MAPST) on a set of points as a spanning tree that has the minimal possible sum of lengths of links with the constraint that starting from any link, the lengths of the links are non-increasing towards a root node. We define similarly MAPSTs with more than one root. We present some algorithms for finding such trees. Based on these trees, we devise a test for multimodality, called the MAP Test (for Minimal Ascending Path). Using simulations, we estimate percentage points of the MAP statistic and assess the power of the test. Finally, we illustrate the use of MAPSTs for determining the number of modes in a distribution of positions of galaxies on photographic plates from a rich galaxy cluster.     

Optimal selection of forecasts

Many studies have shown that, in general, a combination of forecasts often outperforms the forecasts of a single model or expert. In this paper we postulate that obtaining forecasts is costly, and provide models for optimally selecting them. Based on normality assumptions, we derive a dynamic programming procedure for maximizing precision net of cost. We examine the solution for cases where the forecasters are independent, correlated and biased. We provide illustrative examples for each case.     

The maximum and minimum of primary forecasts

The purpose of this paper is to suggest that the maximum (or minimum) of a number of primary forecasts may make a valuable addition to the forecasting accuracy of a combination of forecasts. Such forecasts are readily computable. Theoretical results are presented for two unbiased forecasts with correlated normally distributed errors, showing that the maximum (minimum) of two forecasts can have a smaller error variance than either of the primary forecasts and the forecast error can have low correlation with the primary errors. Empirical results are obtained for two different sets of forecasts available in the literature, and it is observed that a combination forecast including the maximum and/or minimum has attractive forecasting properties.     

基于目标函数梯度向量的相邻方向共轭法

从共轭梯度法的基本思想出发,在前一寻优方向起点和终点的负梯度向量平移所决定的平面内确定共轭方向,并提出二维和三维优化问题的共轭方向计算公式。根据向量的几何关系和矢量加减运算的几何意义,推导由任一寻优方向起点和终点的梯度所确定的共轭方向。此方法可用于多维优化问题的求解。提出新算法的寻优步骤,并与众多经典共轭方向计算公式相比。该算法不仅具有理论严密性,而且寻优有效,具有二次终止性。     

基于NNI注视指数的塔台管制员情景意识研究

为研究塔台管制员在任务不同阶段的注视模式与情景意识（Situation Awareness,SA）的关系,搭建模拟塔台管制的眼动试验平台,设计3组不同难度的试验,用NASA-TLX量表评估被试的任务负荷,利用方差分析方法验证试验难度设计的合理性;利用3D-SART量表评估被试的SA水平,利用NNI算法分别计算和识别试验前期和后期被试的注视模式,并结合操作绩效,分析不同任务难度下管制员前期和后期的NNI注视指数与SA的关系。结果表明,被试在试验后期的NNI注视指数受试验难度的影响更为显著,且试验后期NNI注视模式呈离散型分布的被试具有更高的SA水平和操作绩效。     

电力生产预测计划软件设计

根据电力系统生产的特点，本文给出了电力系统生产指标的定量预测和计划编制算法，介绍了软件系统设计的思路和特点。     

张量空间中可合元素图的基本结构

应用诱导生成子图的方法,研究了可合张量的图论性质。通过讨论一个顶点和它的两个相邻顶点的诱导生成子图的结构,指出三角形和平形四边形结构是可合张量的图的基本结构,得到了由图论语言表达的可合张量的充分必要条件。     

基于神经网络的河南省经济增长模型

经济增长是一个多变量因素影响,具有复杂的非解析函数关系的系统。本文将人工神经网络用于经济增长的建模与预测之中,采用滚动优化技术把样本数据按时间序列化,使网络在训练过程中不断学习新的信息,提高网络的预测精度。经对河南省经济增长的模拟与预测,验证了该方法的可行性。