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61.
Although it has been determined that gambling is a popular activity amongst the young, there seems to be a lack of studies examining developmental differences in children's gambling behavior. This study examines developmental differences in children's blackjack gambling behavior. One hundred and four students (51 males; 53 females) from grades 4, 6, and 8 completed a questionnaire examining their gambling behavior in general and individually played a computerized blackjack game with the following data being recorded: percentage of accuracy, amounts of money bet, gross winnings, percentage of wins, number of hands played, and end balance. Findings revealed few developmental differences in prevalence and frequency of gambling behavior and performance on a blackjack task. Males were found to wager greater amounts of money and have larger gross winnings than females on the blackjack task. Furthermore, males were more likely to view gambling as involving both large amounts of skill and luck, thus suggesting an illusion of control for gambling activities. The results are discussed from a cognitive developmental perspective.This research was partially supported by a grant from the McGill University Social Science Computer Committee. The authors would like to thank the administration, staff, and students in T.H. Bowes, Prince Charles, Souvenir, Gerald McShane, Our Lady of Pompei, Pierrefond Comprehensive High School, and Western Laval High School, for their participation and cooperation in this study.This is a revision of a paper presented at the Ninth International Conference on Gambling and Risk-Taking, Las Vegas, 1994.  相似文献   
62.
Salary line forecasting assumes a relevant role in manpower and in pension funds Previously, the authors presented a generalized Bernoulli process, useful for forecasting the evolution of salary lines, taking into account the salary costs, the number of workers at each rank and the probability transitions between the ranks. The problem with applying this model is constructing the probability of transition between the grades. In this article, we will present a model that allows obtaining these probabilities by means of the solution of the evolution equation of a generalization of continuous time non-homogeneous semi-Markov processes.  相似文献   
63.
Analysis of scientific debate on the determinants of procreational choice leads the author to identify four main decisional logics: primary adaptation, economic rationality, norm internalization and identity reinforcement. Revisiting the classics supports the hypothesis of a bipolarity of strategical principles governing fluctuating reproductive behaviour. In particular, dialectics between the two endogenous strategies — economic rationality and identity rationality — suggests the use of the Volterra-Kostitsin predator-prey model as a metaphor to account for fertility waves.  相似文献   
64.
In this paper the class of Bilinear GARCH (BL-GARCH) models is proposed. BL-GARCH models allow to capture asymmetries in the conditional variance of financial and economic time series by means of interactions between past shocks and volatilities. The availability of likelihood based inference is an attractive feature of BL-GARCH models. Under the assumption of conditional normality, the log-likelihood function can be maximized by means of an EM type algorithm. The main reason for using the EM algorithm is that it allows to obtain parameter estimates which naturally guarantee the positive definiteness of the conditional variance with no need for additional parameter constraints. We also derive a robust LM test statistic which can be used for model identification. Finally, the effectiveness of BL-GARCH models in capturing asymmetric volatility patterns in financial time series is assessed by means of an application to a time series of daily returns on the NASDAQ Composite stock market index.  相似文献   
65.
We investigate the behavior of the well-known Hylleberg, Engle, Granger and Yoo (HEGY) regression-based seasonal unit root tests in cases where the driving shocks can display periodic nonstationary volatility and conditional heteroskedasticity. Our set up allows for periodic heteroskedasticity, nonstationary volatility and (seasonal) generalized autoregressive-conditional heteroskedasticity as special cases. We show that the limiting null distributions of the HEGY tests depend, in general, on nuisance parameters which derive from the underlying volatility process. Monte Carlo simulations show that the standard HEGY tests can be substantially oversized in the presence of such effects. As a consequence, we propose wild bootstrap implementations of the HEGY tests. Two possible wild bootstrap resampling schemes are discussed, both of which are shown to deliver asymptotically pivotal inference under our general conditions on the shocks. Simulation evidence is presented which suggests that our proposed bootstrap tests perform well in practice, largely correcting the size problems seen with the standard HEGY tests even under extreme patterns of heteroskedasticity, yet not losing finite sample relative to the standard HEGY tests.  相似文献   
66.
The article presents the results of a qualitative study investigating the experiences of a sample of Italian adolescents during the COVID-19 pandemic. Data were analysed in the light of the two social representations (adolescents as criminals and as victims) that permeated the Italian public debate throughout the outbreak. The findings showed the ability of boys and girls in dealing with the relationships altered by the pandemic constraints and in adapting to different regulations. This demonstrated their competence as social actors, neither criminals nor victims, who were also able to cope with the coronavirus risk in safeguarding their significant others.  相似文献   
67.
68.
In this study, we present a generalization of spatial power indexes able to overcome their main limitations, namely (i) the excessive concentration of power measures; (ii) the too high sensitivity to players’ location in the ideological space. Voters’ propensity to support an issue is modeled via a random utility function with two additive terms: the deterministic term accounts for voters’ preference-driven/predictable behavior; the random one is a catch-all term that accounts for all the idiosyncratic/unpredictable factors. The relative strength of the two terms gives rise to a continuum of cases ranging from the Shapley value, where all aggregation patterns are equally probable, to a standard spatial value, like the Owen–Shapley index, where instead the conditional order is fully deterministic. As an illustrative application, we analyze the distribution of power in the Council of Ministers under three different scenarios: (i) EU15 Pre-Nice; (ii) EU27 Nice Treaty; (iii) EU27 Lisbon Treaty.  相似文献   
69.
Purpose: To investigate a possible relation between penile Doppler ultrasound examination (PDUE) parameters and efficacy of chronic therapy with tadalafil (TAD) combined with a protocol of aerobic physical activity (PA) in patients with late onset hypogonadism (LOH). Methods: The study evaluated 30 patients consecutively enrolled with LOH and erectile dysfunction which present contraindication to hormonal replacement therapy for concomitant prostate disease. These patients were subjected to a combined protocol with phosphodiesterase V selective inhibitors (TAD 5?mg daily) and aerobic PA.

Results: After three months, we observed significant improvements in erectile function [IIEF-5, median (IQR)?=?13.0 (7.0–18.0) versus 6.0 (5.0–6.75); p?p?Conclusion: PA in association with phosphodiesterase V inhibitors could compensate the effects of hypogonadism on erectile function and facilitate the clinical response to these drugs even in the absence of adequate serum concentrations of total testosterone.  相似文献   
70.
The paper provides a general framework for investigating the effects of permanent changes in the variance of the errors of an autoregressive process on unit root tests. Such a framework - which is based on a novel asymptotic theory for integrated and near integrated processes with heteroskedastic errors - allows to evaluate how the variance dynamics affect the size and the power function of unit root tests. Contrary to previous studies, it is shown that non-constant variances can both inflate and deflate the rejection frequency of the commonly used unit root tests, both under the null and under the alternative, with early negative and late positive variance changes having the strongest impact on size and power. It is also shown that shifts smoothed across the sample have smaller impacts than shifts occurring as a single abrupt jump, while periodic variances have a negligible effect even when a small number of cycles take place over a given sample. Finally, it is proved that the locally best invariant (LBI) test of a unit root against level stationarity is robust to heteroskedasticity of any form under the null hypothesis.  相似文献   
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