全文获取类型
收费全文 | 401篇 |
免费 | 6篇 |
国内免费 | 10篇 |
专业分类
管理学 | 85篇 |
民族学 | 3篇 |
人口学 | 20篇 |
丛书文集 | 13篇 |
理论方法论 | 13篇 |
综合类 | 225篇 |
社会学 | 1篇 |
统计学 | 57篇 |
出版年
2024年 | 2篇 |
2023年 | 1篇 |
2022年 | 6篇 |
2021年 | 4篇 |
2020年 | 9篇 |
2019年 | 7篇 |
2018年 | 11篇 |
2017年 | 18篇 |
2016年 | 14篇 |
2015年 | 9篇 |
2014年 | 15篇 |
2013年 | 32篇 |
2012年 | 27篇 |
2011年 | 30篇 |
2010年 | 21篇 |
2009年 | 28篇 |
2008年 | 27篇 |
2007年 | 39篇 |
2006年 | 28篇 |
2005年 | 17篇 |
2004年 | 17篇 |
2003年 | 12篇 |
2002年 | 10篇 |
2001年 | 9篇 |
2000年 | 10篇 |
1999年 | 5篇 |
1998年 | 3篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1992年 | 1篇 |
排序方式: 共有417条查询结果,搜索用时 15 毫秒
411.
412.
Xiaojie Xu 《Journal of applied statistics》2017,44(14):2593-2620
Using daily prices from 496 corn cash markets for July 2006–February 2011, this study investigates short-run forecast performance of 31 individual and 10 composite models for each market at horizons of 5, 10, and 30 days. Over the performance evaluation period September 2010–February 2011, two composite models are optimal across horizons for different markets based on the mean-squared error. For around half of the markets at the horizon of 5 days and most of them at 10 and 30 days, the mean-squared error of a market's optimal model is significantly different from those of at least other 23 models evaluated for it. Root-mean-squared error reductions through switching from non-optimal models to the optimal are generally around 0.40%, 0.55%, and 0.87% at horizons of 5, 10, and 30 days. 相似文献
413.
A new method for forming composite turning-point (or other qualitative) forecasts is proposed. Rather than forming composite forecasts by the standard Bayesian approach with weights proportional to each model's posterior odds, weights are assigned to the individual models in proportion to the probability of each model's having the correct turning-point prediction. These probabilities are generated by logit models estimated with data on the models' past turning-point forecasts. An empirical application to gross national product/gross domestic product forecasting of 18 Organization for Economic Cooperation and Development countries demonstrates the potential benefits of the procedure 相似文献
414.
《Journal of Statistical Computation and Simulation》2012,82(1-2):39-45
A composite forecast combines two or more individual forecasts into a single estimate by way of a number of different averaging schemes. The easiest way to combine forecasts is through using a simple average. In this paper, the authors show that in many instances the simple average of individual forecasts approximates the optimal combining scheme. Results are expressed in terms of the probability that a composite forecast will improve upon an individual forecast. 相似文献
415.
根据国际煤炭市场价格的特性,建立了国际煤炭市场价格预测的随机序列线性模型,应用实际数据回归出预测方程并检验了模型。 相似文献
416.
针对企业收益额预测,提出了一种嵌入知识的综合集成预测方法。首先,基于系统思想,提出了嵌入知识的人-机交互式综合集成预测方法框架;进而重点介绍了集成预测方法中的信息预处理、预测模型选择、效果检验等关键子模块;最后,以某公司的收益额预测为例,验证了其有效性。 相似文献
417.
Halbert White 《Econometrica : journal of the Econometric Society》2000,68(5):1097-1126
Data snooping occurs when a given set of data is used more than once for purposes of inference or model selection. When such data reuse occurs, there is always the possibility that any satisfactory results obtained may simply be due to chance rather than to any merit inherent in the method yielding the results. This problem is practically unavoidable in the analysis of time‐series data, as typically only a single history measuring a given phenomenon of interest is available for analysis. It is widely acknowledged by empirical researchers that data snooping is a dangerous practice to be avoided, but in fact it is endemic. The main problem has been a lack of sufficiently simple practical methods capable of assessing the potential dangers of data snooping in a given situation. Our purpose here is to provide such methods by specifying a straightforward procedure for testing the null hypothesis that the best model encountered in a specification search has no predictive superiority over a given benchmark model. This permits data snooping to be undertaken with some degree of confidence that one will not mistake results that could have been generated by chance for genuinely good results. 相似文献