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   308篇
  免费   11篇
管理学   54篇
民族学   3篇
人口学   23篇
丛书文集   1篇
理论方法论   58篇
综合类   12篇
社会学   136篇
统计学   32篇
  2021年   1篇
  2020年   6篇
  2019年   11篇
  2018年   6篇
  2017年   17篇
  2016年   13篇
  2015年   15篇
  2014年   11篇
  2013年   36篇
  2012年   19篇
  2011年   14篇
  2010年   5篇
  2009年   11篇
  2008年   13篇
  2007年   8篇
  2006年   7篇
  2005年   8篇
  2004年   9篇
  2003年   17篇
  2002年   5篇
  2001年   6篇
  2000年   7篇
  1999年   2篇
  1998年   7篇
  1996年   8篇
  1995年   3篇
  1994年   6篇
  1993年   7篇
  1992年   5篇
  1991年   4篇
  1990年   1篇
  1989年   2篇
  1987年   3篇
  1986年   2篇
  1985年   3篇
  1982年   2篇
  1981年   2篇
  1980年   1篇
  1979年   1篇
  1978年   4篇
  1976年   1篇
  1974年   3篇
  1973年   1篇
  1971年   3篇
  1970年   2篇
  1967年   1篇
排序方式: 共有319条查询结果,搜索用时 15 毫秒
121.
Feature costing is a topic of recent discussion related to cost management systems (CMSs) aimed at understanding how product features influence production process costs. It raises as a key issue in mass customisation environments where a single product model can present hundreds of menu options. In this study, we explore the concept of feature costing beyond the use of activity-based costing (ABC). We propose a CMS based on features and common elements as costing objects instead of products. In our model, we use the unit of production effort method to organise the direct manufacturing costs, ABC method to address the indirect cost and the standard methods to compute raw materials costs. We illustrate the method in the production of bus seats in a Brazilian manufacturing company. This study gives different perspectives to the international academic community on the use of a different CMS used by many Brazilian companies.  相似文献   
122.
We propose a Bayesian approach for inference in a dynamic disequilibrium model. To circumvent the difficulties raised by the Maddala and Nelson (1974 Maddala , G. , Nelson , F. ( 1974 ). Maximum likelihood methods for models of markets in disequilibrium . Econometrica 42 ( 6 ): 10131030 .[Crossref], [Web of Science ®] [Google Scholar]) specification in the dynamic case, we analyze a dynamic extended version of the disequilibrium model of Ginsburgh et al. (1980 Ginsburgh , V. , Tishler , A. , Zang , I. ( 1980 ). Alternative estimation methods for two regime models . European Economic Review 13 : 207228 .[Crossref], [Web of Science ®] [Google Scholar]). We develop a Gibbs sampler based on the simulation of the missing observations. The feasibility of the approach is illustrated by an empirical analysis of the Polish credit market, for which we conduct a specification search using the posterior deviance criterion of Spiegelhalter et al. (2002 Spiegelhalter , D. J. , Best , N. G. , Carlin , B. P. , Van Der Linde , A. ( 2002 ). Bayesian measures of complexity and fit . Journal of the Royal Statistical Society, Ser. B 64 : 583639 .[Crossref] [Google Scholar]).  相似文献   
123.
Asymptotic normality of frequency polygons for random fields   总被引:1,自引:0,他引:1  
The purpose of this paper is to investigate asymptotic normality of the frequency polygon estimator of a stationary mixing random field indexed by multidimensional lattice points space ZNZN. Appropriate choices of the bandwidths are found.  相似文献   
124.
Next‐generation sequencing (NGS) data present an untapped potential to improve microbial risk assessment (MRA) through increased specificity and redefinition of the hazard. Most of the MRA models do not account for differences in survivability and virulence among strains. The potential of machine learning algorithms for predicting the risk/health burden at the population level while inputting large and complex NGS data was explored with Listeria monocytogenes as a case study. Listeria data consisted of a percentage similarity matrix from genome assemblies of 38 and 207 strains of clinical and food origin, respectively. Basic Local Alignment (BLAST) was used to align the assemblies against a database of 136 virulence and stress resistance genes. The outcome variable was frequency of illness, which is the percentage of reported cases associated with each strain. These frequency data were discretized into seven ordinal outcome categories and used for supervised machine learning and model selection from five ensemble algorithms. There was no significant difference in accuracy between the models, and support vector machine with linear kernel was chosen for further inference (accuracy of 89% [95% CI: 68%, 97%]). The virulence genes FAM002725, FAM002728, FAM002729, InlF, InlJ, Inlk, IisY, IisD, IisX, IisH, IisB, lmo2026, and FAM003296 were important predictors of higher frequency of illness. InlF was uniquely truncated in the sequence type 121 strains. Most important risk predictor genes occurred at highest prevalence among strains from ready‐to‐eat, dairy, and composite foods. We foresee that the findings and approaches described offer the potential for rethinking the current approaches in MRA.  相似文献   
125.
Understanding donor profiles is crucial for donor relationship management. Whereas previous research has focused on profiling blood, money, or time donor segments separately, we define seven donor profiles based on their former donation behavior for blood, money, and time donation and compare them to non‐donors. Relying on representative data from the German Socio Economic Panel, we use an extensive set of characteristics that include sociodemographic, psychographic, health‐related, and geographical measures and simultaneously investigate profiles of donors for single and multiple donation forms and non‐donors by means of a multinomial logistic model. Our results reveal valuable insights for donor acquisition and retention strategies of nonprofit organizations along the identified profiling characteristics of donor segments. By this, our findings help nonprofit organization managers to better target single and multiple donors across three donation forms.  相似文献   
126.
127.
The paper focuses upon the impact of changing relations between farmers and spouses in the context of the restructuring of the rural economy and increasing female participation in labour markets. It is based upon a study of the connections between the succession process in agriculture and family relationships [Blanc, M. and Perrier-Cornet, P. (1989) Renouvellement des forces de travail et formes de production familiales en agriculture (les installations d'agriculteurs au cours de la decennie soixante-dix). Montpellier, INRA, Departement d'Economie et de Sociologie Rurales, Montpellier]. It argues that for farmer's wives, off-farm work, participation in other farm-based enterprises and occupational status result from a negotiation of power relations within the farm operating couple. Such changes are bringing about a distinct form of pluriactivity among farm families, with an emerging trend towards husbands being occupied full-time on-farm and wives off-farm.The paper deals with the future of family farming in connection with these changes. The role played by the ideology of family farming in sustaining these emerging forms of production is examined. The individuation of aspirations, especially for women, is considered an important factor in terms of labour market involvement. However, it is argued that the resolution of the impact of such changes on the domestic sphere and the farm is dependent upon a process of negotiation between the farmer and spouse.  相似文献   
128.
129.
We compare EM, SEM, and MCMC algorithms to estimate the parameters of the Gaussian mixture model. We focus on problems in estimation arising from the likelihood function having a sharp ridge or saddle points. We use both synthetic and empirical data with those features. The comparison includes Bayesian approaches with different prior specifications and various procedures to deal with label switching. Although the solutions provided by these stochastic algorithms are more often degenerate, we conclude that SEM and MCMC may display faster convergence and improve the ability to locate the global maximum of the likelihood function.  相似文献   
130.
Adult judges were presented with videotape segments showing an infant displaying facial configurations hypothesized to express discomfort/pain, anger, or sadness according to differential emotions theory (Izard, Dougherty, & Hembree, 1983). The segments also included the infant's nonfacial behavior and aspects of the situational context. Judges rated the segments using a set of emotion terms or a set of activity terms. Results showed that judges perceived the discomfort/pain and anger segments as involving one or more negative emotions not predicted by differential emotions theory. The sadness segments were perceived as involving relatively little emotion overall. Body activity accompanying the discomfort/pain and anger configurations was judged to be more jerky and active than body activity accompanying the sadness configurations. The sadness segments were accompanied by relatively little body movement overall. The results thus fail to conform to the predictions of differential emotions theory but provide information that may contribute to the development of a theory of infant expressive behavior.This article is based on the second author's master's thesis. The authors thank Dennis Ross for his expert assistance in the data analyses.  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