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61.
Generally, the semiclosed-form option pricing formula for complex financial models depends on unobservable factors such as stochastic volatility and jump intensity. A popular practice is to use an estimate of these latent factors to compute the option price. However, in many situations this plug-and-play approximation does not yield the appropriate price. This article examines this bias and quantifies its impacts. We decompose the bias into terms that are related to the bias on the unobservable factors and to the precision of their point estimators. The approximated price is found to be highly biased when only the history of the stock price is used to recover the latent states. This bias is corrected when option prices are added to the sample used to recover the states' best estimate. We also show numerically that such a bias is propagated on calibrated parameters, leading to erroneous values. The Canadian Journal of Statistics 48: 8–35; 2020 © 2019 Statistical Society of Canada  相似文献   
62.
A common approach taken in high‐dimensional regression analysis is sliced inverse regression, which separates the range of the response variable into non‐overlapping regions, called ‘slices’. Asymptotic results are usually shown assuming that the slices are fixed, while in practice, estimators are computed with random slices containing the same number of observations. Based on empirical process theory, we present a unified theoretical framework to study these techniques, and revisit popular inverse regression estimators. Furthermore, we introduce a bootstrap methodology that reproduces the laws of Cramér–von Mises test statistics of interest to model dimension, effects of specified covariates and whether or not a sliced inverse regression estimator is appropriate. Finally, we investigate the accuracy of different bootstrap procedures by means of simulations.  相似文献   
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The situation of families undergoing separation in a context of co‐occurrence of intimate partner violence (IPV) and child maltreatment raises certain issues related to child custody. The results presented in this paper were collected and analysed within the framework of a qualitative study aiming to identify the principal points of agreement and the main controversies amongst practitioners in several different types of organizations. Focus groups were held with a total of 43 practitioners from six different settings concerned with child custody in cases of co‐occurrence of IPV and child maltreatment. Although they agreed on the importance of ensuring the safety of victims of violence, their views diverged on three points: (1) the importance of preserving the father–child relationship; (2) collaboration between voluntary organizations and semi‐voluntary or legal agencies; and (3) consideration of cultural differences.  相似文献   
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This paper investigates how individuals evaluate delayed outcomes with risky realization times. Under the discounted expected utility (DEU) model, such evaluations depend only on intertemporal preferences. We obtain several testable hypotheses using the DEU model as a benchmark and test these hypotheses in three experiments. In general, our results show that the DEU model is a poor predictor of intertemporal choice behavior under timing risk. We found that individuals are averse to timing risk and that they evaluate timing lotteries in a rank-dependent fashion. The main driver of timing risk aversion is nothing but probabilistic risk aversion that stems from the nonlinear treatment of probabilities.  相似文献   
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This article analyzes the effects of debt management and its consequence for the control of base money in a small open economy (Belgium). The study compares the effects obtained from a small theoretical model with the results of a larger empirical model.The theoretical model focuses on the financing of government by money operation, on the bond rate, and on the international reserve of the Central Bank.The empirical model is a medium-term one, including the demand and the supply sectors of the economy and permitting simultaneous analysis of real and financial variables.The effects of an endogeneous or exogenous debt management have been studied by numerical simulation of modification in the public expenditure, the world trade, and the discount rate.  相似文献   
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Hall MF  Reinke WA 《Demography》1969,6(3):335-346
The technique of multi-sort analysis was used to compare the relative duration of use of oral and intrauterine contraception among low socio-economic groups in Baltimore City. The clinical records of over 12,000 women who had received contraception through the Baltimore public services were analyzed. The type of method a woman used was found to be the most important factor affecting her probability of continuing contraception. Her age, race, and how long she had been using the method also influenced this probability. The strictness of the criteria used for the definition of continuation rates and the fact that experience was incomplete for many intrauterine contraceptors probably in part explain the somewhat low continuation rates obtained for both methods. It is suggested that the intrinsic characteristics of each method may lead to a clinical impression favoring the oral even when statistical evidence, as presented here, favors the intrauterine method.  相似文献   
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It is unclear whether long-term aerobic (AT) or resistance (RT) training can improve insulin sensitivity (IS) beyond the residual effect of the last training bout in older women (54-78 years). Therefore, a group of nonobese, healthy older women underwent 6 months of AT (n = 8) or RT (n = 10), and the authors measured IS 4 days after the last training bouts using the hyperinsulinemic-euglycemic clamp technique. Women trained 3 days/week. AT consisted of 25- to 60-min sessions of walking/jogging at 60-95% of maximal heart rate. RT consisted of three sets of nine exercises repeated 10 times at 80% of 1 repetition maximum. AT decreased fat mass, whereas both AT and RT increased fat-free mass. Neither training program, however, improved absolute or relative rates of glucose disposal. The authors therefore concluded that nonobese, healthy older women should perform AT or RT on a daily basis in order to improve IS and maintain the improvement.  相似文献   
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