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81.
This article analyzes the mechanisms and effects of innovative financial instruments that a central public administration (CPA) may adopt to minimize the flood risk in particularly exposed regions. The pattern we suggest assumes that in risky areas the CPA can issue two financial instruments, called project options and CAT‐bonds, producing a dynamic interaction among three types of agents: the CPA itself, the local public administrations, and private investors. We explore the possible scenarios of such interaction and the conditions under which the CPA's goal of maximal risk reduction is attained. This pattern is proposed for flood risk mitigation in the city of Florence, where the model dynamics are tested assuming parameters obtained from engineering studies.  相似文献   
82.
This study addresses the controversial issue of how non-financial performance affects the cost of debt capital and access to it. The relationship between corporate social performance and two measures of debt cost (accounting-based and market-based) and the measure of debt access are analysed by means of a multi-theoretical framework combining economics with social theories. By observing a sample of listed European non-financial firms over an 8-year period from 2005 to 2012, we find a negative relationship between corporate social performance and interest rate. Consistent with this result, we find a positive relationship between corporate social performance and debt rating. Thus, corporate social performance has a positive role in reducing the cost of debt capital. Moreover, firms with better corporate social performance are more attractive to lenders in terms of leverage allowance. Overall, our findings provide deeper insight into the reasons why companies should improve their corporate social performance.  相似文献   
83.
A new rank correlation index, which can be used to measure the extent of concordance or discordance between two rankings, is proposed. This index is based on Gini’s mean difference computed on the totals ranks corresponding to each unit and it turns out to be a special case of a more general measure of the agreement of m rankings. The proposed index can be used in a test for the independence of two criteria used to rank the units of a sample, against their concordance/discordance. It can then be regarded as a competitor of other classical methods, such as Kendall’s tau. The exact distribution of the proposed test-statistic under the null hypothesis of independence is studied and its expectation and variance are determined; moreover, the asymptotic distribution of the test-statistic is derived. Finally, the implementation of the proposed test and its performance are discussed. Both the authors contributed equally to this work; however, the actual writing of the paper was as follows: Sects. 2 and 3 are due to C. G. Borroni, Sects. 1 and 4 are due to M. Zenga.  相似文献   
84.
In this paper, we describe a new statistical method for images which contain discontinuities. The method tries to improve the quality of a 'measured' image, which is degraded by the presence of random distortions. This is achieved by using knowledge about the degradation process and a priori information about the main characteristics of the underlying ideal image. Specifically, the method uses information about the discontinuity patterns in small areas of the 'true' image. Some auxiliary labels 'explicitly' describe the location of discontinuities in the true image. A Bayesian model for the image grey levels and the discontinuity labels is built. The maximum a posteriori estimator is considered. The iterated conditional modes algorithm is used to find a (local) maximum of the posterior distribution. The proposed method has been successfully applied to both artificial and real magnetic resonance images. A comparison of the results with those obtained from three other known methods also has been performed. Finally, the connection between Bayesian 'explicity and 'implicit' models is studied. In implicit modelling, there is no use of any set of labels explicitly describing the location of discontinuities. For these models, we derive some constraints of the function by which the presence of the discontinuities is taken into account.  相似文献   
85.
ABSTRACT

While the climate-migration nexus raises crucial questions of mobility and climate justice, it is commonly understood through simplistic narratives that reify a complex set of relations. The spectre of environmentally-induced exodus is recurrent in media, policy and activist circles, in spite of numerous studies that reveal the empirical flaws and noxious normative implications of such narratives. This article explores this insistence and the desire(s) for there to be a reified relation between climate and migration such insistence reveals. The article proceeds in three movements. First, it situates discourses on climate migration in relation to the crisis of humanism the Anthropocene signifies. Second, it operates a symptomatic reading of climate migration discourses, drawing on two understandings of symptom elaborated by Lacan – as ‘return of the repressed’ and as ‘Sinthome’. Read as a symptom, the figure of the climate migrant/refugee appears as the return of fundamental contradictions that carve contemporary regimes of socioecological (re)production. Through the concept of ‘Sinthome’, discourses on climate migration can be read as (illusory) attempts to shore up for the waning consistence of modern forms of ‘being human’. Finally, the article proposes a symptomatic reading of the Anthropocene itself, and elaborates on what the dissolution of this symptom/ Sinthome would entail.  相似文献   
86.
Discussing the foundations of the minimax principle, Savage (1954) argued that it is utterly untenable for statistics because it is ultrapessimistic when applied to negative income, but claimed that such objection is not relevant when the principle is applied to regret. In this paper I rebut the latter claim. I first present an example where ultrapessimism, as Savage understood it, applies to minimax regret but not to minimax negative income. Then, for a sequential decision problems with two terminal acts and a finite number of states of nature, I give necessary and sufficient conditions for a decision rule to be ultrapessimistic, and show that for every payoff table with at least three states, be it in regret form or not, there exist an experiment such that the minimax rule is ultrapessimistic. I conclude with some more general remarks on information and the value of experimentation for a minimax agent.  相似文献   
87.
This paper uses a data base covering the universe of French firms for the period 1990–2007 to provide a forensic account of the role of individual firms in generating aggregate fluctuations. We set up a simple multisector model of heterogeneous firms selling to multiple markets to motivate a theoretically founded decomposition of firms' annual sales growth rate into different components. We find that the firm‐specific component contributes substantially to aggregate sales volatility, mattering about as much as the components capturing shocks that are common across firms within a sector or country. We then decompose the firm‐specific component to provide evidence on two mechanisms that generate aggregate fluctuations from microeconomic shocks highlighted in the recent literature: (i) when the firm size distribution is fat‐tailed, idiosyncratic shocks to large firms directly contribute to aggregate fluctuations, and (ii) aggregate fluctuations can arise from idiosyncratic shocks due to input–output linkages across the economy. Firm linkages are approximately three times as important as the direct effect of firm shocks in driving aggregate fluctuations.  相似文献   
88.
We examined the psychometric characteristics of the long and abbreviated versions of the Multidimensional Students’ Life Satisfaction Scale (MSLSS) in the Italian contexts. In study 1 we assessed the factorial validity and reliability of the long and abbreviated versions of the MSLSS among Italian adolescents, while in study 2 we assessed the convergent validity of the abbreviated Italian version of the MSLSS by examining the associations between life satisfaction and well-established measures of adjustment. Furthermore, we explored the effect of adolescent gender and age on life satisfaction. Participants in the study 1 were 996 adolescents (48 % males) from 14 to 18 years of age (M = 16.06; SD = 1.51). Participants in study 2 were 380 adolescents (52 % males) from 14 to 19 years of age (M = 15.76; SD = 1.65). Confirmatory factor analyses confirmed the hypothesized five-factor solution of the MSLSS, with a better goodness of fit for the abbreviated version of MSLSS. Moreover, indices of internal consistency revealed acceptable reliability coefficients across the five domains. Convergent validity was confirmed by the expected associations between the domains of the MSLSS and indexes of adjustment. Finally, results evidenced age differences, with oldest adolescents showing the highest levels of satisfaction on most of the domains.  相似文献   
89.
The Hotelling’s \(\textit{T}^{2 }\) control chart with variable parameters (VP \(T^{2})\) has been shown to have better statistical performance than other adaptive control schemes in detecting small to moderate process mean shifts. In this paper, we investigate the statistical performance of the VP \(T^{2}\) control chart coupled with run rules. We consider two well-known run rules schemes. Statistical performance is evaluated by using a Markov chain modeling the random shock mechanism of the monitored process. The in-control time interval of the process is assumed to follow an exponential distribution. A genetic algorithm has been designed to select the optimal chart design parameters. We provide an extensive numerical analysis indicating that the VP \(T^{2}\) control chart with run rules outperforms other charts for small sizes of the mean shift expressed through the Mahalanobis distance.  相似文献   
90.
This article develops a novel asymptotic theory for panel models with common shocks. We assume that contemporaneous correlation can be generated by both the presence of common regressors among units and weak spatial dependence among the error terms. Several characteristics of the panel are considered: cross-sectional and time-series dimensions can either be fixed or large; factors can either be observable or unobservable; the factor model can describe either a cointegration relationship or a spurious regression, and we also consider the stationary case. We derive the rate of convergence and the limit distributions for the ordinary least square (OLS) estimates of the model parameters under all the aforementioned cases.  相似文献   
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