全文获取类型
收费全文 | 818篇 |
免费 | 72篇 |
国内免费 | 16篇 |
专业分类
财政金融 | 132篇 |
工业经济 | 64篇 |
计划管理 | 283篇 |
经济学 | 89篇 |
综合类 | 59篇 |
运输经济 | 17篇 |
旅游经济 | 12篇 |
贸易经济 | 88篇 |
农业经济 | 64篇 |
经济概况 | 98篇 |
出版年
2024年 | 1篇 |
2023年 | 19篇 |
2022年 | 39篇 |
2021年 | 34篇 |
2020年 | 45篇 |
2019年 | 26篇 |
2018年 | 14篇 |
2017年 | 27篇 |
2016年 | 31篇 |
2015年 | 43篇 |
2014年 | 88篇 |
2013年 | 61篇 |
2012年 | 69篇 |
2011年 | 71篇 |
2010年 | 59篇 |
2009年 | 31篇 |
2008年 | 37篇 |
2007年 | 43篇 |
2006年 | 25篇 |
2005年 | 32篇 |
2004年 | 27篇 |
2003年 | 16篇 |
2002年 | 9篇 |
2001年 | 16篇 |
2000年 | 8篇 |
1999年 | 6篇 |
1998年 | 7篇 |
1997年 | 1篇 |
1996年 | 5篇 |
1995年 | 3篇 |
1994年 | 5篇 |
1992年 | 3篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1985年 | 1篇 |
排序方式: 共有906条查询结果,搜索用时 15 毫秒
21.
Salim Lahmiri Stelios Bekiros Anastasia Giakoumelou Frank Bezzina 《International Journal of Intelligent Systems in Accounting, Finance & Management》2020,27(1):3-9
Financial data classification plays an important role in investment and banking industry with the purpose to control default risk, improve cash and select the best customers. Ensemble learning and classification systems are becoming gradually more applied to classify financial data where outputs from different classification systems are combined. The objective of this research is to assess the relative performance of existing state‐of‐the‐art ensemble learning and classification systems with applications to corporate bankruptcy prediction and credit scoring. The considered ensemble systems include AdaBoost, LogitBoost, RUSBoost, subspace, and bagging ensemble system. The experimental results from three datasets: one is composed of quantitative attributes, one encompasses qualitative data, and another one combines both quantitative and qualitative attributes. By using ten‐fold cross‐validation method, the experimental results show that AdaBoost is effective in terms of low classification error, limited complexity, and short time processing of the data. In addition, the experimental results show that ensemble classification systems outperform existing models that were recently validated on the same databases. Therefore, ensemble classification system can be employed to increase the reliability and consistency of financial data classification task. 相似文献
22.
Accurate aircraft trajectory predictions are necessary to compute exact traffic demand figures, which are crucial for an efficient and effective air traffic flow and capacity management. At present, the uncertainty of the take-off time is one of the major contributions to the loss of trajectory predictability. In the EUROCONTROL Maastricht Upper Area Control Centre, the predicted take-off time for each individual flight relies on the information received from the Enhanced Traffic Flow Management System. However, aircraft do not always take-off at the times reported by this system due to several factors, which effects and interactions are too complex to be expressed with hard-coded rules. Previous work proposed a machine learning model that, based on historical data, was able to predict the take-off time of individual flights from a set of input features that effectively captures some of these elements. The model demonstrated to reduce by 30% the take-off time prediction errors of the current system one hour before the time that flight is scheduled to depart from the parking position. This paper presents an extension of the model, which overcomes this look-ahead time constraint and allows to improve take-off time predictions as early as the initial flight plan is received. In addition, a subset of the original set of input features has been meticulously selected to facilitate the implementation of the solution in an operational air traffic flow and capacity management system, while minimising the loss of predictive power. Finally, the importance and interactions of the input features are thoroughly analysed with additive feature attribution methods. 相似文献
23.
本文主要根据2001-2011年江苏省用电量样本数据,建立了江苏省电力负荷与人均GDP、工业化以及人口数之间的多元回归预测方程,并预测了江苏省2014-2020年总用电量数据,在此基础上提出了相应的建议。 相似文献
24.
25.
Stewart Jones David Johnstone Roy Wilson 《Journal of Business Finance & Accounting》2017,44(1-2):3-34
Corporate bankruptcy prediction has attracted significant research attention from business academics, regulators and financial economists over the past five decades. However, much of this literature has relied on quite simplistic classifiers such as logistic regression and linear discriminant analysis (LDA). Based on a large sample of US corporate bankruptcies, we examine the predictive performance of 16 classifiers, ranging from the most restrictive classifiers (such as logit, probit and linear discriminant analysis) to more advanced techniques such as neural networks, support vector machines (SVMs) and “new age” statistical learning models including generalised boosting, AdaBoost and random forests. Consistent with the findings of Jones et al. ( 2015 ), we show that quite simple classifiers such as logit and LDA perform reasonably well in bankruptcy prediction. However, we recommend the use of “new age” classifiers in corporate bankruptcy modelling because: (1) they predict significantly better than all other classifiers on both the cross‐sectional and longitudinal test samples; (2) the models may have considerable practical appeal because they are relatively easy to estimate and implement (for instance, they require minimal researcher intervention for data preparation, variable selection and model architecture specification); and (3) while the underlying model structures can be very complex, we demonstrate that “new age” classifiers have a reasonably good level of interpretability through such metrics as relative variable importances (RVIs). 相似文献
26.
This study aimed to investigate land use planning around airports, by employing Remote Sensing (RS) and Geographic Information Systems (GIS), in conjunction with an optimization algorithm using an Integrated Noise Model (INM) software, to establish the potential effects of aircraft noise at Imam Khomeini International Airport (IKIA) in Tehran. We also checked for land use compatibility with the noise levels around IKIA and the residents' reaction to the noise. The research was carried out in three stages: a) the establishment of Strategic Noise Map (SNM) scenarios of the airport operation in the years 2011, 2020 and 2030 using the INM software; b) the assessment of the results with emphasis on the study area land uses and application of RS and GIS and the exposure of residents at different levels of environmental noise; and c) the assessment of the intensity of aircraft noise annoyance at various times of day and night. The results indicated that developing IKIA together with the residential development will increase airport noise. Hence proper management and control of noise at IKIA is essential. 相似文献
27.
本文通过全面剖析影响交通冲突的原因,以交通流量、道路几何设计和道路环境三方面的因素建立指标层次结构体系。提出基于模糊层次分析(FAHP)法优化BP神经网络(BPNN)的预测模型,应用于交通冲突预测。 相似文献
28.
29.
Daniel E. O'leary 《International Journal of Intelligent Systems in Accounting, Finance & Management》2011,18(2-3):121-144
This paper investigates the capabilities of social media, such as Facebook, Twitter, Delicious, Digg and others, for their current and potential impact on the supply chain. In particular, this paper examines the use of social media to capture the impact on supply‐chain events and develop a context for those events. This paper also analyses the use of social media in the supply chain to build relationships among supply‐chain participants. Further, this paper investigates the of use of user‐supplied tags as a basis of evaluating and extending an ontology for supply chains. In addition, using knowledge discovery from social media, a number of concepts related to the supply chain are examined, including supply‐chain reputation and influence within the supply chain. Prediction markets are analysed for their potential use in supply chains. Finally, this paper investigates the integration of traditional knowledge management along with knowledge generated from social media. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
30.
Abnormal Returns from Takeover Prediction Modelling: Challenges and Suggested Investment Strategies 下载免费PDF全文
Jo Danbolt Antonios Siganos Abongeh Tunyi 《Journal of Business Finance & Accounting》2016,43(1-2):66-97
While takeover targets earn significant abnormal returns, studies tend to find no abnormal returns from investing in predicted takeover targets. In this study, we show that the difficulty of correctly identifying targets ex ante does not fully explain the below‐expected returns to target portfolios. Target prediction models’ inability to optimally time impending takeovers, by taking account of pre‐bid target underperformance and the anticipation of potential targets by other market participants, diminishes but does not eliminate the potential profitability of investing in predicted targets. Importantly, we find that target portfolios are predisposed to underperform, as targets and distressed firms share common firm characteristics, resulting in the misclassification of a disproportionately high number of distressed firms as potential targets. We show that this problem can be mitigated, and significant risk‐adjusted returns can be earned, by screening firms in target portfolios for size, leverage and liquidity. 相似文献