智能模糊控制器

给出了一种智能模糊控制器的设计方法。这种控制器由专家系统形式的智能协调器、连续模糊控制器、模糊预估器及模糊前馈控制器几部分构成,在专家系统的协调下,通过开环与闭环相结合、位置与增量相结合的调节方式,给出了接近最优的控制策略.仿真结果也证实了这一点。     

Extraseasonal ensemble numerical predictions of winter climate over China

Using the nine-level Atmospheric General Circulation Model developed at the Institute of Atmospheric Physics (IAP9L-AGCM) under the Chinese Academy of Sciences, 30-year extraseasonal short-term ensemble hincast of winter climate is performed, with integrations starting from annual autumn during 1969—1998. Winter climate predictability over China is then evaluated for the first time. It follows that the predictability is higher in tropics than in extratropics. Also, it is higher over ocean compared with land, especially for surface air temperature. With height increasing in troposphere, the predictability of geopotential height slightly changes zonally, but for weakening of band-ship distribution and dropping near the date line. Of all analyzed variables, the prediction skill of air temperature and geopotential height (precipitation) is the highest (smallest). In addition, the predictability of winter climate over China and even East Asia enhances obviously during ENSO cycle, especially during La Nia phase. Simulation comparison against verifying analysis for surface temperature anomaly exhibits the model抯 skill in predicting surface temperature抯 interannual variation trend in winter.     

Directional news impact curve

The directional news impact curve (DNIC) is a relationship between returns and the probability of next period's return exceeding a certain threshold—zero in particular. Using long series of S&P500 index returns and a number of parametric models suggested in the literature, as well and flexible semiparametric models, we investigate the shape of the DNIC and forecasting abilities of these models. The semiparametric approach reveals that the DNIC has complicated shapes characterized by nonsymmetry with respect to past returns and their signs, heterogeneity across the thresholds, and changes over time. Simple parametric models often miss some important features of the DNIC, but some nevertheless exhibit superior out‐of‐sample performance.     

应用逻辑信息法对某超基性岩带含矿性的预测

本区研究程度较低,区内已知岩体16个,其中仅一个岩体具工业价值镍矿。作者借用国内其它地质条件可对应的少数含矿岩体作为模型,用所需模型较少的逻辑信息法进行统计,研究时引进了含矿度(H),求得了储量与含矿度间的回归方程,并用此方程预测得15个岩体的镍资源量。     

A comparison of temperature density forecasts from GARCH and atmospheric models

Density forecasts for weather variables are useful for the many industries exposed to weather risk. Weather ensemble predictions are generated from atmospheric models and consist of multiple future scenarios for a weather variable. The distribution of the scenarios can be used as a density forecast, which is needed for pricing weather derivatives. We consider one to 10‐day‐ahead density forecasts provided by temperature ensemble predictions. More specifically, we evaluate forecasts of the mean and quantiles of the density. The mean of the ensemble scenarios is the most accurate forecast for the mean of the density. We use quantile regression to debias the quantiles of the distribution of the ensemble scenarios. The resultant quantile forecasts compare favourably with those from a GARCH model. These results indicate the strong potential for the use of ensemble prediction in temperature density forecasting. Copyright © 2004 John Wiley & Sons, Ltd.     

定量特尔斐预测的经验贝叶斯估计法

本文主要探讨利用贝叶斯估计法改进特尔斐预测精确度的可能性。作为示例,着重讨论了时间域和空间域两种典型的预测类型,并通过设想的例子阐明了这种方法的具体应用。     

灰色GM(1,1)模型参数估计的目标规划法

在灰色G（1，1）预测模型中，参数的估计是非常重要的。本文是在考虑考虑离散后的方程两端偏差的绝对值之和达到最小确定参数，参数的估计的被转化为目标规划问题。     

煤矿井下瓦斯涌出量的动态预测

本文用灰色系统理论的GM(1,1)模型,对于铜川矿务局陈家山矿的瓦斯涌出量进行了动态预测。     

纤维端头裂纹对复合材料有效性能的影响

利用自洽有限元法研究了在纤维端点界面脱粘的短纤维复合材料的有弹弹性性能问题，计算了含有纤维端头裂纹的单向短纤维复合材料的有效纵向拉伸模量和纵向剪切模量，并分析了体分比，刚度比，长径比等物理，几何因素的影响，通过与现有结果的比较，证实了本文结果的合理性，研究表明，纤维端头裂纹对效纵向拉伸模量和剪切模量均有明显的影响。