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151.
152.
In this paper, we present a multivariate version of the skewed log-Birnbaum–Saunders regression model. This new family of distributions holds good properties such as marginal variables following univariate skewed log-Birnbaum–Saunders distributions, besides presenting the usual log-Birnbaum–Saunders distribution as a particular case. Furthermore, the model parameters are estimated through maximum-likelihood methods, a closed-form expression for the Fisher’s information matrix is presented, and testing hypothesis for model parameters is performed. Two real datasets are analyzed and results are discussed.  相似文献   
153.
We propose a measure for interaction for factorial designs that is formulated in terms of a probability similar to the effect size of the Mann–Whitney test. It is shown how asymptotic confidence intervals can be obtained for the effect size and how a statistical test can be constructed. We further show how the test is related to the test proposed by Bhapkar and Gore [Sankhya A, 36:261–272 (1974)]. The results of a simulation study indicate that the test has good power properties and illustrate when the asymptotic approximations are adequate. The effect size is demonstrated on an example dataset.  相似文献   
154.

Background

School shootings have approached epidemic levels in recent years. While mental illness is undoubtedly involved in nearly all cases of mass school violence, we sought to determine how environmental context may exacerbate preexisting personal factors. The present study investigated the associations between mass school shootings, school enrollment size, student–teacher ratios, and student transitions.

Method

Our sample consisted of twenty-two mass school shooting cases between January 1995 and June 2014. Information about school shootings was gathered using preexisting school shooting databases and news media reports. Using state and national databases, data regarding school size and student–teacher ratios of incident schools were collected. Information about schools where shooters previously attended, as well as state average school statistics, were also obtained.

Findings

Schools where mass shootings occurred had significantly higher enrollments than their state average counterparts. Additionally, students who committed a mass school shooting were significantly more likely to have previously attended a school with a smaller student body and/or a lower than state average student–teacher ratio.

Conclusion

Our findings are consistent with previous literature indicating that smaller schools are less likely to experience acts of mass violence. Additionally, our results suggest that transitioning from a smaller, more supportive school to a larger, more anonymous school may exacerbate preexisting mental health issues among potential school shooters. The results of this study have significant implications for educational policy reform.  相似文献   
155.
Parent involvement in the process of creating an Individualized Education Plan (IEP) is authorized under the Individuals with Disabilities Education Act, a federal law in the United States that ensures children with disabilities have the opportunity to receive a free appropriate public education alongside their peers without disabilities in the least restrictive environment. Yet much research has shown that parents often feel like outsiders during the process. To understand parent perspectives about how educators might help make the IEP process more collaborative and inclusive, this study collected qualitative data from 35 parents of students with disabilities who have worked to develop an IEP with a school team. Our findings provide insight into parent experiences and evidence that parents have many suggestions for how educators can improve the IEP process. In our discussion section, we provide educators with strategies to address parent suggestions.  相似文献   
156.
ABSTRACT

Researchers often approach employers to investigate employees’ work and family experiences. Organizational willingness to grant access to employees can vary, especially when the research topic is seen as controversial or contentious for the employer. This paper explores this methodological challenge using a research example from Manitoba, Canada, which explored the use of parental leave by male employees and the impact of managerial attitudes and corporate culture on usage. Sixty large employers were recruited with only seven of those organizations agreeing to participate. In this paper, the reasons organizations gave for declining to participate and the implications of their decisions for the research are examined. Although the final sample included 905 managers and employees, participating organizations tended to be employee-focused and family-friendly employers. Organizations declined participation for a variety of reasons: avoiding raising the issue with unions, awareness that their policies unfairly benefited female leave takers, and simply not seeing the relevance of a topic relating to men’s work–family experiences. A dialogue often absent from the literature, it is important to understand how employers can limit researchers’ access to employees on controversial topics. The existence of such barriers suggests alternative avenues to recruit participants directly when topics are contentious for employers.  相似文献   
157.
ABSTRACT

This paper outlines the notion of ‘algorithmic technique’ as a middle ground between concrete, implemented algorithms and the broader study and theorization of software. Algorithmic techniques specify principles and methods for doing things in the medium of software and they thus constitute units of knowledge and expertise in the domain of software making. I suggest that algorithmic techniques are a suitable object of study for the humanities and social science since they capture the central technical principles behind actual software, but can generally be described in accessible language. To make my case, I focus on the field of information ordering and, first, discuss the wider historical trajectory of formal or ‘mechanical’ reasoning applied to matters of commerce and government before, second, moving to the investigation of a particular algorithmic technique, the Bayes classifier. This technique is explicated through a reading of the original work of M. E. Maron in the early 1960 and presented as a means to subject empirical, ‘datafied’ reality to an interested reading that confers meaning to each variable in relation to an operational goal. After a discussion of the Bayes classifier in relation to the question of power, the paper concludes by coming back to its initial motive and argues for increased attention to algorithmic techniques in the study of software.  相似文献   
158.
In a recent article from the Annals of Applied Statistics, Cox discussed the main phases of applied statistical research ranging from clarifying study objectives to final data analysis and interpreting results. As an incidental remark to these main phases, we advocate that beyond cleaning and preprocessing the data, it is a good practice to audit the data to determine if they can be trusted at all. A case study based on Ghanaian Official Fishery Statistics is used to illustrate this need, with Benford's law being the tool used to carrying out the data audit. Supplementary materials for this article are available online.  相似文献   
159.
The Yule–Simon distribution has been out of the radar of the Bayesian community, so far. In this note, we propose an explicit Gibbs sampling scheme when a Gamma prior is chosen for the shape parameter. The performance of the algorithm is illustrated with simulation studies, including count data regression, and a real data application to text analysis. We compare our proposal to the frequentist counterparts showing better performance of our algorithm when a small sample size is considered.  相似文献   
160.
Case–control design to assess the accuracy of a binary diagnostic test (BDT) is very frequent in clinical practice. This design consists of applying the diagnostic test to all of the individuals in a sample of those who have the disease and in another sample of those who do not have the disease. The sensitivity of the diagnostic test is estimated from the case sample and the specificity is estimated from the control sample. Another parameter which is used to assess the performance of a BDT is the weighted kappa coefficient. The weighted kappa coefficient depends on the sensitivity and specificity of the diagnostic test, on the disease prevalence and on the weighting index. In this article, confidence intervals are studied for the weighted kappa coefficient subject to a case–control design and a method is proposed to calculate the sample sizes to estimate this parameter. The results obtained were applied to a real example.  相似文献   
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