首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1245篇
  免费   30篇
  国内免费   2篇
财政金融   187篇
工业经济   37篇
计划管理   533篇
经济学   248篇
综合类   36篇
运输经济   27篇
旅游经济   48篇
贸易经济   75篇
农业经济   25篇
经济概况   61篇
  2024年   6篇
  2023年   60篇
  2022年   51篇
  2021年   64篇
  2020年   85篇
  2019年   85篇
  2018年   50篇
  2017年   50篇
  2016年   37篇
  2015年   26篇
  2014年   84篇
  2013年   123篇
  2012年   68篇
  2011年   95篇
  2010年   39篇
  2009年   49篇
  2008年   46篇
  2007年   41篇
  2006年   29篇
  2005年   28篇
  2004年   20篇
  2003年   33篇
  2002年   14篇
  2001年   10篇
  2000年   8篇
  1999年   4篇
  1998年   8篇
  1997年   7篇
  1996年   8篇
  1995年   3篇
  1993年   3篇
  1992年   3篇
  1991年   1篇
  1990年   2篇
  1988年   3篇
  1987年   3篇
  1986年   3篇
  1985年   9篇
  1984年   9篇
  1983年   4篇
  1982年   5篇
  1981年   1篇
排序方式: 共有1277条查询结果,搜索用时 15 毫秒
51.
Imad A. Moosa 《Applied economics》2016,48(44):4201-4209
Some economists suggest that the failure of exchange-rate models to outperform the random walk in exchange rate forecasting out of sample can be attributed to failure to take into account cointegration when it is present. We attempt to find out if cointegration matters for forecasting accuracy by examining the relation between the stationarity and size of the forecasting error. Results based on three macroeconomic models of exchange rates do not provide strong support for the proposition that cointegration matters for forecasting accuracy. The simulation results show that while stationary errors tend to be smaller than non-stationary errors, this is not a universal rule. Irrespective of the presence or absence of cointegration, none of the three models can outperform the random walk in out-of-sample forecasting, which means that cointegration cannot solve the Meese–Rogoff puzzle.  相似文献   
52.
53.
In this paper, we establish a generalized two-regime Markov-switching GARCH model which enables us to specify complex (symmetric and asymmetric) GARCH equations that may differ considerably in their functional forms across the two Markov regimes. We show how previously proposed collapsing procedures for the Markov-switching GARCH model can be extended to estimate our general specification by means of classical maximum-likelihood methods. We estimate several variants of the generalized Markov-switching GARCH model using daily excess returns of the German stock market index DAX sampled during the last decade. Our empirical study has two major findings. First, our generalized model outperforms all nested specifications in terms of (a) statistical fit (when model selection is based on likelihood ratio tests) and (b) out-of-sample volatility forecasting performance. Second, we find significant Markov-switching structures in German stock market data, with substantially differing volatility equations across the regimes.  相似文献   
54.
This article looks into the ‘fine print’ of boosting for economic forecasting. By using German industrial production for the period from 1996 to 2014 and a data set consisting of 175 monthly indicators, we evaluate which indicators get selected by the boosting algorithm over time and four different forecasting horizons. It turns out that a number of hard indicators like turnovers, as well as a small number of survey results, get selected frequently by the algorithm and are therefore important to forecasting the performance of the German economy. However, there are indicators such as money supply that never get chosen by the boosting approach at all.  相似文献   
55.
Air transport demand forecasting is receiving increasing attention, especially because of intrinsic difficulties and practical applications. Total passengers are used as a proxy for air transport demand. However, the air passenger time series usually has a complex behavior due to their irregularity, high volatility and seasonality. This paper proposes a new hybrid approach, combining singular spectrum analysis (SSA), adaptive-network-based fuzzy inference system (ANFIS) and improved particle swarm optimization (IPSO), for short-term air passenger traffic prediction. The SSA is used for identifying and extracting the trend and seasonality of air transport demand and the artificial intelligence technologies, including ANFIS and IPSO, are utilized to deal with the irregularity and volatility of the demand. The HK air passenger data are collected to establish and validate the forecasting model. Empirical results clearly points to the enormous potential that the proposed approach possesses in air transport demand forecasting and can be considered as a viable alternative.  相似文献   
56.
Summary

Because of pressures on the countryside by private housing development, the Government and the planners have become increasingly involved in planning policy issues and in forecasting land requirements. The forecasting techniques used are examined, and their translation into local allocations through structure and local plans and land availability studies are looked at. The demand for more land releases is attributed more to structural changes in the housebuilding industry and local land shortages in the south‐east than to real shortfalls in housing provision. There is a need for improved monitoring systems for land resource management, particularly in balancing ‘green‐field’ releases against development/redevelopment in existing urban areas.  相似文献   
57.
运用GARCH类模型对沪深300指数序列的波动性、收益率进行了实证研究,并且对序列做了拟合与预测,获得了不错的效果。除此,还证实了中国股市存在着显著的非对称效应。  相似文献   
58.
文章介绍了红水河岩滩水电站水文预报的方案、内容及作业方法。  相似文献   
59.
We investigate the relative impact of internal Delphi process factors - including panelists' degree of confidence, expertise, majority/minority positioning - and an external factor, richness of feedback - on opinion change and subsequent accuracy of judgmental forecasts. We found that panelists who had low confidence in their judgmental forecast and/or who were in a minority were more likely to change their opinion than those who were more confident and/or in a majority. The addition of rationales, or reasons, to the numeric feedback had little impact upon panelists' final forecasts, despite the quality of panelists' rationales being significantly positively correlated with accurate forecasts and thus of potential use to aid forecast improvement over Delphi rounds. Rather, the effect of rationales was similar to that of confidence: to pull panelists towards the majority opinion regardless of its correctness. We conclude that majority opinion is the strongest influence on panelists' opinion change in both the ‘standard’ Delphi, and Delphi-with-reasons. We make some suggestions for improved variants of the Delphi-with-reasons technique that should help reduce majority influence and thereby permit reasoned arguments to exert their proper pull on opinion change, resulting in forecast accuracy improvements over Delphi rounds.  相似文献   
60.
Technology has been the driving force of development for knowledge-based economies. As competition in technology innovation among nations becomes more intense, there is a growing need for improved judgment, evaluation and prediction of scientific technology capacity in order to enhance national competitiveness. Until now, a country's technology level has been evaluated on a relative basis by comparing it with that of the country with the world's best technology. However, this kind of static methodology makes the interpretation of results unclear and makes time series analysis difficult. One of the most important limitations of this methodology is that it cannot be used to establish a strategy to improve the technology level. This paper examines the methodological problems of technology level evaluation and develops a dynamic methodology by applying the technology growth curve model. We also analyze the real technology level by using a new model application and review the relevance of this method. Finally, we discuss how to use the results in order to create a dynamic technology strategy.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号