首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   320篇
  免费   12篇
管理学   45篇
民族学   3篇
人口学   23篇
理论方法论   16篇
社会学   158篇
统计学   87篇
  2023年   2篇
  2022年   2篇
  2021年   9篇
  2020年   14篇
  2019年   20篇
  2018年   19篇
  2017年   18篇
  2016年   21篇
  2015年   10篇
  2014年   13篇
  2013年   39篇
  2012年   67篇
  2011年   19篇
  2010年   18篇
  2009年   6篇
  2008年   8篇
  2007年   5篇
  2006年   4篇
  2005年   5篇
  2004年   1篇
  2003年   1篇
  2002年   3篇
  2001年   3篇
  2000年   2篇
  1999年   4篇
  1997年   1篇
  1996年   2篇
  1995年   1篇
  1994年   1篇
  1993年   2篇
  1992年   1篇
  1991年   4篇
  1990年   1篇
  1988年   1篇
  1987年   2篇
  1986年   1篇
  1985年   1篇
  1982年   1篇
排序方式: 共有332条查询结果,搜索用时 15 毫秒
221.
In this paper, we introduce the class of beta seasonal autoregressive moving average (βSARMA) models for modelling and forecasting time series data that assume values in the standard unit interval. It generalizes the class of beta autoregressive moving average models [Rocha AV and Cribari-Neto F. Beta autoregressive moving average models. Test. 2009;18(3):529–545] by incorporating seasonal dynamics to the model dynamic structure. Besides introducing the new class of models, we develop parameter estimation, hypothesis testing inference, and diagnostic analysis tools. We also discuss out-of-sample forecasting. In particular, we provide closed-form expressions for the conditional score vector and for the conditional Fisher information matrix. We also evaluate the finite sample performances of conditional maximum likelihood estimators and white noise tests using Monte Carlo simulations. An empirical application is presented and discussed.  相似文献   
222.
Reverse logistics problems arising in municipal waste management are both wide-ranging and varied. The usual collection system in UE countries is composed of two phases. First, citizens leave their refuse at special collection areas where different types of waste (glass, paper, plastic, organic material) are stored in special refuse bins. Subsequently, each type of waste is collected separately and moved to its final destination (a recycling plant or refuse dump). The present study focuses on the problem of locating these collection areas. We establish the relationship between the problem, the set covering problem and the MAX-SAT problem and then go on to develop a genetic algorithm and a GRASP heuristic to, respectively, solve each formulation. Finally, the quality of the algorithms is tested in a computational experience with real instances from the metropolitan area of Barcelona, as well as a reduced set of set covering instances from the literature.  相似文献   
223.
The purpose of the present study was to evaluate whether near wins can prolong gambling activity on a video lottery terminal. In a three-reel game, near wins were operationally defined as two identical symbols followed by a third different symbol. Players in an experimental condition were exposed to 27% near wins in a series of continuous losses, whereas players in a control group were exposed to none. Participants played as long as they wished, and received real money for their wins. The results showed that players in the near win condition played 33% more games than did the control group. The results of this study suggest that near wins can be added to the list of factors that may motivate people to gamble despite the probability of monetary loss.  相似文献   
224.
Hospital admissions for psychiatric disorders in the City of Calgary were reviewed during a six-month period. Rates of hospitalization for the city's 77 census tract areas were calculated and correlated with data collected in the 1976 Canada Census. The study identified areas in the city with high rates of pathology requiring hospitalization. The correlational analysis reveals a significant association between differential admission rates and demographic and ecological attributes such as age, marital status, population stability, housing tenure, crowding, social disintegration and isolation and unemployment. Of these correlates, the proportion of persons aged 65 years and over and the number of families in each of the census tract areas were shown to be the most important factors influencing rates of psychiatric hospitalization.  相似文献   
225.
Organizational scholars increasingly view institutionalization as a process through which actors adapt or translate seemingly successful practices in a field to create variations that are specific to their own organization. Yet little is known about how outsiders who seek to diffuse ‘best practice’ affect translation. We examined interactions between management consultants and their clients in two different consulting projects, which focused on embedding the practice of ‘lean’ in one and the practice of a quality improvement framework in the other. Our findings provide insights into the processes of translation through which promoters and adopters iterate at different stages to reach a compromise, illuminating how the evolution of an imported practice signals the outcome of a negotiation. Furthermore, we demonstrate that management practices are not translated in isolation but enveloped by peripheral practices that are adopted by association. We highlight how the peripheral practice of benchmarking, in both cases, was rarely contested or negotiated and thus proved more resistant to translation. Our analysis allows us to unpack the agency inherent within translation‐as‐negotiation and integrate research on diffusion and translation.  相似文献   
226.
A statistical method is presented to determine the optima design of air quality networks detecting warning and alert levels. A simulation model is used to describe temporal and spatial variations of atmospheric pollutants; air quality patterns serve as the database of the procedure to design the network. Only the sites exceeding warning and alert levels, at different meteorological scenarios, are considered as potential monitoring stations. For the selection of the optima set, spatial and temporal representativity criteria are introduced; accordingly, the optima set provides a complete representativity of the space and time considered. The method is applied to the Mestre urban area, in Venice district, for the carbon monoxide pollutant.  相似文献   
227.
Factor analysis is a flexible technique for assessment of multivariate dependence and codependence. Besides being an exploratory tool used to reduce the dimensionality of multivariate data, it allows estimation of common factors that often have an interesting theoretical interpretation in real problems. However, standard factor analysis is only applicable when the variables are scaled, which is often inappropriate, for example, in data obtained from questionnaires in the field of psychology, where the variables are often categorical. In this framework, we propose a factor model for the analysis of multivariate ordered and non-ordered polychotomous data. The inference procedure is done under the Bayesian approach via Markov chain Monte Carlo methods. Two Monte Carlo simulation studies are presented to investigate the performance of this approach in terms of estimation bias, precision and assessment of the number of factors. We also illustrate the proposed method to analyze participants'' responses to the Motivational State Questionnaire dataset, developed to study emotions in laboratory and field settings.  相似文献   
228.
The adequacy of facilities and the individual securities in their different age groups is importance to ensure greater functionality to them, allowing full development of daily activities. For this to occur more efficiently it is necessary the use of ergonomics which can ensure more comfort and safety for end users of products and spaces. The present study aimed to measure body dimensions of a representative sample of children aged 6 to 11 years old, children of graduate and pos graduate students, faculty and staff of the Federal University of Vicosa and also residents of the city of Vicosa, State of Minas Gerais, Brazil, coming from different municipalities of State of Minas Gerais, to organize a database that will provide the furniture industry, anthropometric variables more appropriate to design products for both the leisure activities, and for the school sector. To realize this research we used the methodology proposed by the authors Panero and Zelnik, based on samples distributed in six age groups, and providing a measurement of 10 variables. By applying the methodology to the field was possible to compare the observed data, with the tables of the aforementioned authors. The main results revealed a significant variation of the 10 variables analyzed, and it is believed that this variation could lead to possible flaws in the designs of products that use the data from these authors. The completion of the study provided data on Vicosa considered more appropriate for the design of products and environments for the population of the study, considering age and region, of Brazil (State of Minas Gerais) and it is believed that the future may expand to the Brazilian population, with the progress of study of this nature.  相似文献   
229.
This article intends to evaluate the lung function and capacity to exercise and correlate both of them in metal industry workers.  相似文献   
230.
The enforcement of accessibility today has faced several difficulties, such as intervention in historic buildings that now house public services and cultural activities, such as town halls, museums and theaters and should allow access, on equal terms to all people. The paper presents the application of a method for evaluating the spatial accessibility conditions and their results. For this, we sought to support the theoretical foundation about the main issue involved and legislation. From the method used--guided walks--it was possible to identify the main barriers to accessibility in historic buildings. From the identified barriers, possible solutions are presented according to the four components of accessibility: spatial orientation, displacement, use and communication. It is hoped also that the knowledge gained in this research contributes to an improvement of accessibility legislation in relation to the listed items.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号