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   676篇
  免费   27篇
财政金融   234篇
工业经济   40篇
计划管理   162篇
经济学   61篇
综合类   10篇
运输经济   2篇
旅游经济   12篇
贸易经济   161篇
农业经济   7篇
经济概况   14篇
  2023年   6篇
  2022年   3篇
  2021年   9篇
  2020年   24篇
  2019年   20篇
  2018年   41篇
  2017年   31篇
  2016年   26篇
  2015年   16篇
  2014年   33篇
  2013年   129篇
  2012年   15篇
  2011年   40篇
  2010年   24篇
  2009年   38篇
  2008年   35篇
  2007年   24篇
  2006年   21篇
  2005年   24篇
  2004年   20篇
  2003年   21篇
  2002年   13篇
  2001年   14篇
  2000年   13篇
  1999年   9篇
  1998年   5篇
  1997年   19篇
  1996年   8篇
  1995年   6篇
  1994年   1篇
  1993年   5篇
  1992年   2篇
  1991年   2篇
  1990年   1篇
  1986年   1篇
  1985年   1篇
  1982年   1篇
  1981年   1篇
  1979年   1篇
排序方式: 共有703条查询结果,搜索用时 109 毫秒
111.
本文将组织中的非核心业务流程划分为关键型、支持型、通用型三种类型,制定了包含资质、能力、合作三个维度的外包供应商评价体系,并说明了不同类型的非核心业务流程在决策时可选用的指标。  相似文献   
112.
Inspired by some works of Kirkby, J. L. [2015. Efficient option pricing by frame duality with the fast Fourier transform. SIAM Journal on Financial Mathematics 6(1), 713–747; 2016. An efficient transform method for Asian option pricing. SIAM Journal on Financial Mathematics 7(1), 845–892], we present a systematic study on effectively computing the Gerber–Shiu function in the Lévy risk model, where the frame duality projection is used for approximation. By introducing an auxiliary function, we provide a smooth extension of the Gerber–Shiu function, which has closed-form Fourier transform and is differentiable over the whole real line under some conditions. The objective function is approximated by its frame duality projection onto a Riesz basis, and the projection coefficients are readily computed by the fast Fourier transform algorithm. Error analysis is made and the effectiveness of our results will be further illustrated in the numerical experiments.  相似文献   
113.
This study assesses the nature of networking between youth and agricultural policy-makers – given youth disillustionment with agricultural livelihoods. Using the Malawi case, a mixed-methods approach shows, first, that local government departments which are mandated to work on youth issues are the main hubs of information for youth in agriculture. The Ministry of Agriculture plays a secondary role. Second, the study shows that youth in agriculture have little or no direct interactions with each other. Therefore, youth remain on the periphery of agricultural policy-making and their role in shaping agricultural policy dialogue is negligible. This is attributable to both lack of a deliberate government policy to include the youth and lack of a unified youth platform. The onus is therefore on the youth to ensure that they are effectively engaged in agricultural policy dialogue. The study concludes with policy recommendations relevant for countries with a ‘youth/agriculture’ problem like Malawi.  相似文献   
114.
The goal of this paper is to illustrate the potential usefulness of econometrics as a tool to assist private policy makers. We provide a case study and detailed econometric analysis of the automobile replacement policy adopted by a large car rental company. Unlike public policy making–where the benefits from using econometric models and “science-based” approaches to policy making are hard to quantify because the outcomes of interest are typically subjective quantities such as “social welfare”–in the case of firms there is an objective, easily quantifiable criterion for judging whether policy A is better than policy B: profits. We introduce and estimate an econometric model of the rental histories of individual cars in the company’s fleet. Via stochastic simulations, we show that the model provides a good approximation to the company’s actual operations. In particular, the econometric model is able to reproduce the extraordinarily high rates of return that the company obtains on its rental cars, with average internal rates of return between purchase and sale of approximately 50%. However, the econometric model can simulate outcomes under a range of counterfactual vehicle replacement policies. We use the econometric model to simulate the profitability of an alternative replacement policy under pessimistic assumptions about the rate maintenance costs would increase and rental rates would have to be decreased if the company were to keep its rental cars longer than it does under the status quo. Depending on the vehicle type, we find that the company’s expected discounted profits would be between 6% to over 140% higher under the suggested alternative operating strategy where vehicles are kept longer and rental rates of older vehicles are discounted to induce customers to rent them. The company found this analysis to be sufficiently convincing that it undertook an experiment to verify the predictions of the econometric model.  相似文献   
115.
Several studies that have investigated a few stocks have found that the spacing between consecutive financial transactions (referred to as trade duration) tend to exhibit long-range dependence, heavy tailedness, and clustering. In this study, we empirically investigate whether a larger sample of stocks exhibit those characteristics. We do so by comparing goodness of fit in modeling trade duration data for stable distribution and fractional stable noise based on a procedure applying bootstrap methods developed by the authors with several alternative distributional assumptions in modeling trade duration data. The empirical results suggest that the autoregressive conditional duration model with stable distribution fits better than other combinations, while fractional stable noise itself fits better for the time series of trade duration. Our result is consistent with the general findings in the literature that trade duration is informative and that short trade durations move prices more than long trade duration. In addition, our result confirms the advantage of fractal models in the study of roughness in trade duration and provides some evidence for duration dependence. S. Rachev’s research was supported by grants from the Division of Mathematical, Life and Physical Science, College of Letters and Science, University of California, Santa Barbara, and the Deutschen Forschungsgemeinschaft. W. Sun’s research was supported by grants from the Deutschen Forschungsgemeinschaft. P.S. Kalev’s research was supported with a NCG grant from the Faculty of Business and Economics, Monash University. Data are supplied by Securities Industry Research Center of Asia-Pacific (SIRCA) on behalf of Reuters. The first draft of this paper was presented at the International Conference on High Frequency Finance 2006; the authors would like to thank the conference participants for their valuable comments.  相似文献   
116.
The purpose of this paper is to describe the appropriate mathematical framework for the study of the duality principle in option pricing. We consider models where prices evolve as general exponential semimartingales and provide a complete characterization of the dual process under the dual measure. Particular cases of these models are the ones driven by Brownian motions and by Lévy processes, which have been considered in several papers. Generally speaking, the duality principle states that the calculation of the price of a call option for a model with price process S=e H (with respect to the measure P) is equivalent to the calculation of the price of a put option for a suitable dual model S′=e H (with respect to the dual measure P′). More sophisticated duality results are derived for a broad spectrum of exotic options. The second named author acknowledges the financial support from the Deutsche Forschungsgemeinschaft (DFG, Eb 66/9-2). This research was carried out while the third named author was supported by the Alexander von Humboldt foundation.  相似文献   
117.
Lévy driven term structure models have become an important subject in the mathematical finance literature. This paper provides a comprehensive analysis of the Lévy driven Heath–Jarrow–Morton type term structure equation. This includes a full proof of existence and uniqueness in particular, which seems to have been lacking in the finance literature so far.   相似文献   
118.
This paper suggests the study of professionalism and the professionalising processes within public sector organisations. Sociologists propose that professionalism is changing into a new variant developing under the premise of organisational management and control. This paper disputes the perspective that the use of management control leads to deprofessionalisation in terms of the routinisation of reflective professional tasks or weakened professional values. This paper proposes that, with client focus, professionals and accountants can cooperate and create coherence between management control system elements and professional values. This dynamic contributes to the retention of professional values and more reflective work procedures.  相似文献   
119.
We introduce and establish the main properties of QHawkes (‘Quadratic’ Hawkes) models. QHawkes models generalize the Hawkes price models introduced in Bacry and Muzy [Quant. Finance, 2014, 14(7), 1147–1166], by allowing feedback effects in the jump intensity that are linear and quadratic in past returns. Our model exhibits two main properties that we believe are crucial in the modelling and the understanding of the volatility process: first, the model is time-reversal asymmetric, similar to financial markets whose time evolution has a preferred direction. Second, it generates a multiplicative, fat-tailed volatility process, that we characterize in detail in the case of exponentially decaying kernels, and which is linked to Pearson diffusions in the continuous limit. Several other interesting properties of QHawkes processes are discussed, in particular the fact that they can generate long memory without necessarily being at the critical point. A non-parametric fit of the QHawkes model on NYSE stock data shows that the off-diagonal component of the quadratic kernel indeed has a structure that standard Hawkes models fail to reproduce. We provide numerical simulations of our calibrated QHawkes model which is indeed seen to reproduce, with only a small amount of quadratic non-linearity, the correct magnitude of fat-tails and time reversal asymmetry seen in empirical time series.  相似文献   
120.
In this paper we consider the problem of hedging an arithmetic Asian option with discrete monitoring in an exponential Lévy model by deriving backward recursive integrals for the price sensitivities of the option. The procedure is applied to the analysis of the performance of the delta and delta–gamma hedges in an incomplete market; particular attention is paid to the hedging error and the impact of model error on the quality of the chosen hedging strategy. The numerical analysis shows the impact of jump risk on the hedging error of the option position, and the importance of including traded options in the hedging portfolio for the reduction of this risk.  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