富水岩溶隧道Ⅳ级围岩段涌水及注浆加固圈研究

隧道涌水量预测是确保安全施工的重要环节。文章以某隧道Ⅳ级围岩段为例,展开了富水岩隧道Ⅳ级围岩段涌水预测及注浆加固圈研究。     

Forecasting performances of three automated modelling techniques during the economic crisis 2007–2009

In this work we consider the forecasting of macroeconomic variables during an economic crisis. The focus is on a specific class of models, the so-called single hidden-layer feed-forward autoregressive neural network models. What makes these models interesting in the present context is the fact that they form a class of universal approximators and may be expected to work well during exceptional periods such as major economic crises. Neural network models are often difficult to estimate, and we follow the idea of White (2006) of transforming the specification and nonlinear estimation problem into a linear model selection and estimation problem. To this end, we employ three automatic modelling devices. One of them is White’s QuickNet, but we also consider Autometrics, which is well known to time series econometricians, and the Marginal Bridge Estimator, which is better known to statisticians. The performances of these three model selectors are compared by looking at the accuracy of the forecasts of the estimated neural network models. We apply the neural network model and the three modelling techniques to monthly industrial production and unemployment series from the G7 countries and the four Scandinavian ones, and focus on forecasting during the economic crisis 2007–2009. The forecast accuracy is measured using the root mean square forecast error. Hypothesis testing is also used to compare the performances of the different techniques.     

Forecasting commodity price indexes using macroeconomic and financial predictors

Using a long sample of commodity spot price indexes over the period 1947–2010, we examine the out-of-sample predictability of commodity prices by means of macroeconomic and financial variables. Commodity currencies are found to have some predictive power at short (monthly and quarterly) forecast horizons, while growth in industrial production and the investment–capital ratio have some predictive power at longer (yearly) horizons. Commodity price predictability is strongest when based on multivariate approaches that account for parameter estimation error. Commodity price predictability varies substantially across economic states, being strongest during economic recessions.     

中国纺织助剂市场的现状及预测

介绍了中国纺织助剂市场的现状,介绍了未来几年对中国纺织助剂市场影响较大的各种因素.预测了中国纺织助剂市场未来5年的产销额和发展趋势.     

科技投入与科技产出的关联分析及趋势预测

本文基于2002—2007年的年度数据,采用灰色系统理论方法,对我国科技产出与科技投入及其关联关系进行分析和预测。结果显示:目前我国科技成果登记数的发展主要由科技活动人员投入推动,属于低层次的劳动密集型科技发展模式,预计2008—2012年这种状况将得到一定程度的改善;技术市场成交额和发明专利产出数受科技活动经费的影响最大。     

中国能源需求向量自回归模型的建立与分析

随着我国经济的快速发展,对能源需求日益增加,在未来一段时期内,如何科学地预测我国能源需求量,对于保证经济的可持续发展、小康社会目标的实现与和谐社会的构建具有重要的现实意义。向量自回归模型是基于数据的统计性质建立模型,把系统中每一个内生变量作为系统中所有内生变量的滞后值的函数来构造模型,是处理多个相关经济指标的分析和预测最容易操作的模型之一,常用于预测相互联系的时间序列系统。能源需求量是由煤炭、石油、天然气等一次能源的消费量组成,他们之间存在着密切的联系,基于此,应用VAR模型对我国中长期的能源需求总量、煤炭、石油、天然气的消费量进行预测,为科学地制定能源发展战略提供理论指导。     

安徽省道路旅游客运车辆需求量预测分析

本文分别采用指数函数曲线预测模型、灰色简单预测模型和多元线性回归的一般模型预测安徽旅游人数,依据三种方法预测结果的加权平均数,预测了安徽道路旅游客运车辆需求量,为道路旅游客运体系的建立,能够提供科学的决策依据。     

信息不对称、董事会特征与管理层盈余预告披露选择——基于我国A股上市公司2004-2007年数据的实证检验

利用2004年1季度-2007年4季度我国A股上市公司样本数据.本文检验了信息不对称程度、董事会特征与管理层盈余预告选择的关系.结果发现:(1)管理层盈余预告值表达方式精确程度及及时性均随着董事会规模增大及董事会会议频率提高而降低;随着独立董事比例提高,管理层盈余预告值表达方式越精确.(2)在考虑信息不对称程度交互作用后,董事会会议频率与管理层盈余预告值表达方式的精确程度之间负相关程度,以及独立董事比例与管理层盈余预告值表达方式的精确程度的正相关程度,均随着信息不对称程度提高而提高;董事会规模对管理层盈余预告偏差的作用程度,以及独立董事比例对管理层盈余预告偏差的作用程度,都会因信息不对称程度变化而不同.     

基于多维动态模型的中国股指相关性预测研究

运用时间序列的ADCC(Asymmetric Dynamic Conditional Correlation)多维GARCH模型和CCC(Constant Conditional Correlation)多维GARCH模型对中国主要股指之间的相关性进行预测,并对预测结果进行评价和比较,结果表明ADCC多维GARCH模型拟合和预测中国股指相关性较好,这为投资组合管理和风险管理提供了理论支持。     

TSP—把握水产品消费动态的重要方法

本文运用MICRO TSP－计量经济分析软件包,利用18个变量,预测了2000－2001年全国城乡居民家庭水产品消费增长水平。