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51.
Essential graphs and largest chain graphs are well-established graphical representations of equivalence classes of directed acyclic graphs and chain graphs respectively, especially useful in the context of model selection. Recently, the notion of a labelled block ordering of vertices was introduced as a flexible tool for specifying subfamilies of chain graphs. In particular, both the family of directed acyclic graphs and the family of “unconstrained” chain graphs can be specified in this way, for the appropriate choice of . The family of chain graphs identified by a labelled block ordering of vertices is partitioned into equivalence classes each represented by means of a -essential graph. In this paper, we introduce a topological ordering of meta-arrows and use this concept to devise an efficient procedure for the construction of -essential graphs. In this way we also provide an efficient procedure for the construction of both largest chain graphs and essential graphs. The key feature of the proposed procedure is that every meta-arrow needs to be processed only once.  相似文献   
52.
We use data on announced and actual exchange rate arrangements to ask which countries follow de facto regimes different from their de iure ones, that is, do not do what they say. Our results suggest that countries with poor institutional quality have difficulty in maintaining pegging and abandon it often. In contrast, many countries with relatively good institutions display fear of floating, that is, they manage more than announced, perhaps to signal their differences from those countries incapable of maintaining promises of monetary stability. (JEL: F3, O1)  相似文献   
53.
The strategy and innovation literatures argue that organizational competitiveness is contingent upon firms simultaneously pursuing both process and product innovations. A firm’s control system plays a fundamental role in this regard by managing, motivating, and coordinating employees’ behaviors for the development of its innovative capabilities. Research suggests that in order to develop successful innovation, management must use controls that align employees’ interests with those of the organization while simultaneously allowing employee autonomy to encourage creativity. These disparate functions lead to the control–autonomy dilemma. We argue that managers can address this dilemma by recognizing that the effect of controls on innovation outcomes depends, in part, on the controls’ enabling features and the type of commitment they inspire. Our findings show that employee development, which is the focus of input controls, has a direct effect on process innovation-related behaviors while specified goals, the emphasis of output controls, have a direct effect on product innovation-related behaviors. It is only through employees’ perceptions of managerial support that input controls increase product innovation-related behaviors and output controls increase process innovation-related behaviors.  相似文献   
54.
55.
The Information, Education and Communication Division of the Family Planning Organization of the Philippines launched a Happy Family Coupon Campaign, a project to test the feasibility and the potential of a scheme whereby materials were distributed in response to individuals' expressed needs and interest. The project aims were: 1) to reach specific target groups, represented by readers of commercially printed materials; 2) to explore the potential of the mail system as a medium for the distribution of family planning materials; 3) to test the effectiveness of commercial publications as a vehicle for creating demand for family planning information; and 4) to secure feedback regarding preferences for the various family planning materials. The campaign had 2 major components: 1) advertising as a means of informing readers about the availability of certain family planning information materils, and 2) mail service as a channel for delivering requested materials to the respondents. 12 types of informational materials were distributed, each written in English, Filipino, and the Ilocano, Cebuano, and Ilongo dialects. These pamphlets and leaflets are described. The campaign drew a total of 24,226 respondents from August 1974 to December 1975. 58.7% of the respondents had 1-4 children, 26.4% had 5 or more children, and the remaining 14.9% gave no information concerning the number of children. It appears that the project has already achieved a measure of success as indicated by: 1) specific target groups were reached, 2) the potential of the mail system as a channel for the distribution of family planning was not confined to the buyers of the publications, 3) the potential of commercial publications as vehicles for creating demand for family planning information was tested, and 4) feedback regarding preferences of various groups for different family planning materials was obtained.  相似文献   
56.
Models for the assessment of the risk of complex engineering systems are affected by uncertainties due to the randomness of several phenomena involved and the incomplete knowledge about some of the characteristics of the system. The objective of this article is to provide operative guidelines to handle some conceptual and technical issues related to the treatment of uncertainty in risk assessment for engineering practice. In particular, the following issues are addressed: (1) quantitative modeling and representation of uncertainty coherently with the information available on the system of interest; (2) propagation of the uncertainty from the input(s) to the output(s) of the system model; (3) (Bayesian) updating as new information on the system becomes available; and (4) modeling and representation of dependences among the input variables and parameters of the system model. Different approaches and methods are recommended for efficiently tackling each of issues (1)?(4) above; the tools considered are derived from both classical probability theory as well as alternative, nonfully probabilistic uncertainty representation frameworks (e.g., possibility theory). The recommendations drawn are supported by the results obtained in illustrative applications of literature.  相似文献   
57.
Priors are introduced into goodness‐of‐fit tests, both for unknown parameters in the tested distribution and on the alternative density. Neyman–Pearson theory leads to the test with the highest expected power. To make the test practical, we seek priors that make it likely a priori that the power will be larger than the level of the test but not too close to one. As a result, priors are sample size dependent. We explore this procedure in particular for priors that are defined via a Gaussian process approximation for the logarithm of the alternative density. In the case of testing for the uniform distribution, we show that the optimal test is of the U‐statistic type and establish limiting distributions for the optimal test statistic, both under the null hypothesis and averaged over the alternative hypotheses. The optimal test statistic is shown to be of the Cramér–von Mises type for specific choices of the Gaussian process involved. The methodology when parameters in the tested distribution are unknown is discussed and illustrated in the case of testing for the von Mises distribution. The Canadian Journal of Statistics 47: 560–579; 2019 © 2019 Statistical Society of Canada  相似文献   
58.
This paper presents an analytical framework for effective management of projects with uncertain iterations. The framework is based upon: (1) the combination of two complementary techniques, one focused on improving iterative process architectures, the Design Structure Matrix, and one focused on predicting project performance, the Graphical Evaluation Review Technique; and (2) the introduction of an activity set-based criticality measure. The intent of the framework is to help project managers and researchers identify and evaluate alternative process architectures, in order to help them determine the alternative which best balances risk and other project performance parameters, as illustrated through an example application.  相似文献   
59.
This article presents a universal quantile-quantile (QQ) plot that may be used to assess the fit of a family of absolutely continuous distribution functions in a possibly non-homogeneous population. This plot is more general than probability plotting papers because it may be used for distributions having more than two parameters. It is also more general than standard quantile-quantile plots because it may be used for families of not-necessarily identical distributions. In particular, the universal QQ plot may be used in the context of non-homogeneous Poisson processes, generalized linear models, and other general models.  相似文献   
60.
In this article, after having identified the main clusters of food-insecure households worldwide, and summarily analyzed their livelihood profiles, we discuss the interaction and relevance of the most relevant key economic and social factors causing child malnutrition and mortality. On the basis of an essential but consistent World Bank database, covering all developing and transition countries, we also carry out a cross-country econometric analysis on relations of income and non-income factors with child malnutrition and mortality. Our main findings are threefold. First, among income factors, each country's overall level of economic development is paramount, but income distribution also plays an important role. Second, taking into account that public provision of basic services tends to increase with economic growth, each country's relative propensity to spend on basic services is significantly and negatively correlated with child malnutrition and mortality. Third, gender-related cultural factors also play a large role.  相似文献   
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