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311.
Singh et al. ([13]) pointed out that the Randomized response (RR) technique proposed by Moors ([9]) is not desirable because
it fails to protect the confidentiality of the respondents and they provided two alternative strategies free from the above
drawback but limited to SRSWOR sampling only. In this paper, generalization of one of the strategies is provided for complex
survey designs, wider class of estimators and for quantitative characteristics. Relative efficiency of the modified strategy
is tested through empirical investigations.
An erratum to this article is available at . 相似文献
312.
313.
In many situations the applied researcher wishes to combine different data sources without knowing
the exact link and merging rule. This paper considers different cartographic interpolation methods for
interpolating attributes from German employment office districts to German counties and vice versa. In
particular, we apply dasymetric weighting as an alternative to simple area weighting, both of which are
based on estimated intersection areas. We also present conditions under which the choice of interpolation
method does not matter and confirm the theoretical results with a simulation study. Our application to
German administrative data suggests robustness of estimation results of interpolated attributes with respect
to the choice of interpolation method. We provide weighting matrices for regional data sources of the two
largest German data producers. 相似文献
314.
The main problem in applying the mean-variance portfolio selection consists of the fact that the first
two moments of the asset returns are unknown. In practice the optimal portfolio weights have to be estimated.
This is usually done by replacing the moments by the classical unbiased sample estimators. We provide a comparison
of the exact and the asymptotic distributions of the estimated portfolio weights as well as a sensitivity
analysis to shifts in the moments of the asset returns. Furthermore we consider several types of shrinkage
estimators for the moments. The corresponding estimators of the portfolio weights are compared with each
other and with the portfolio weights based on the sample estimators of the moments. We show how the uncertainty
about the portfolio weights can be introduced into the performance measurement of trading strategies. The
methodology explains the bad out-of-sample performance of the classical Markowitz procedures. 相似文献
315.
A data-driven approach for modeling volatility dynamics and co-movements in financial markets
is introduced. Special emphasis is given to multivariate conditionally heteroscedastic factor models in
which the volatilities of the latent factors depend on their past values, and the parameters are driven
by regime switching in a latent state variable. We propose an innovative indirect estimation method
based on the generalized EM algorithm principle combined with a structured variational approach that
can handle models with large cross-sectional dimensions. Extensive Monte Carlo simulations and preliminary
experiments with financial data show promising results. 相似文献
316.
The article presents the results of a survey on statistical consulting at German universities, where
the survey focused on obtaining information on when, where and to whom statistical consulting is provided.
We investigate the financial frame of the activity and question the advantages and disadvantages from a consultant’s
point of view. 相似文献
317.
Martin Becker Ralph Friedmann Stefan Klößner Walter Sanddorf-Köhle 《AStA Advances in Statistical Analysis》2007,91(1):3-21
New tests are proposed for the specification of the intraday price process of a risky asset,
based on open, high, low, and close prices. Under the null of a Brownian process we derive two stochastically
independent, unbiased volatility estimators. For a Hausman specification test we prove its equivalence
with an F-test, consider its robustness against variation in drift and volatility, and analyze the power
against an Ornstein–Uhlenbeck process, as well as a random walk with alternative distributions. 相似文献
318.
The paper and the special issue focus on the activity of statistical consulting and its varieties.
This includes academic consulting, consulting to and in industry as well as statistics in public media. 相似文献
319.
The hypothesis testing and confidence region are considered for the common mean vector of several multivariate normal populations when the covariance matrices are unknown and possibly unequal. A generalized confidence region is derived using the concepts of generalized method based on the generalized p-value. The generalized confidence region is illustrated with two numerical examples. The merits of the proposed method are numerically compared with those of existing methods with respect to their expected area or expected d-dimensional volumes and coverage probabilities under different scenarios. 相似文献
320.
中国基础设施投资对经济增长波动的冲击效应分析 总被引:1,自引:1,他引:1
基础设施是经济发展的重要影响因素,而“基础设施投资促进经济发展”这一主流观点已得到广泛共识,但人们对经济增长与基础设施的探讨仅局限于总量的分析框架,并未对基础设施的类型加以区分,更没发现经济发展的不同阶段对基础设施的需求结构也是不同的。而以“基础设施投资促进经济发展”为出发点,将基础设施投资细分为生产性、生活性、社会性基础设施投资,并分别讨论其对经济的影响。通过邹检验发现:自1994年以来,基础设施投资冲击改变了中国经济增长的特征。其结论是生产性、生活性基础设施对经济增长的影响是明确的、同步的,但社会性基础设施对经济增长的作用是不确定的。因此,加强社会性基础设施投资是一个渐进地逐步推进的过程。 相似文献