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   96篇
  免费   3篇
管理学   17篇
人口学   6篇
理论方法论   4篇
综合类   2篇
社会学   57篇
统计学   13篇
  2023年   1篇
  2022年   3篇
  2021年   1篇
  2020年   4篇
  2019年   3篇
  2018年   3篇
  2017年   3篇
  2016年   2篇
  2015年   3篇
  2014年   4篇
  2013年   14篇
  2012年   23篇
  2011年   4篇
  2010年   1篇
  2009年   6篇
  2008年   1篇
  2007年   3篇
  2006年   3篇
  2005年   3篇
  2004年   4篇
  2003年   2篇
  2002年   3篇
  1998年   1篇
  1997年   1篇
  1995年   1篇
  1992年   2篇
排序方式: 共有99条查询结果,搜索用时 15 毫秒
31.
The cold environment is an indispensable for slaughtering and processing in the poultry industry In field studies it was observed that a large percentage of workers of this sector have hand contact with the cold chicken and / or frozen, have high complaints prevalence of pain and discomfort, mostly in the hands. The contact of human skin with a cold surface may cause pain, numbness and risk of skin damage. Currently, although the use of infrared thermal imaging has been useful in identifying normal and abnormal patterns of heat distribution on the surface of the body. However your use for work tasks and to assess the potential development of injuries related to it has been limited. Based on the physiological responses can be objectively evaluate the effects of the task demands of work and thus contribute to the development of effective strategies for ergonomic intervention. The methodology will be used to evaluate the subjective thermal sensation with analogue scale of ASHRAE and the infrared thermography in the dorsal and palmar hands. Thus the objective of this research is to propose reference values for thermographic hands within limits of comfort.  相似文献   
32.
Although extensive research has found a strong relationship between poor family functioning and depression, previous research has not examined this relationship among low-income Latinos. In this study, we examined how family functioning may be associated with depression in a sample of low-income Latino couples. In addition, we examined how acculturative stress moderates the relationship between family functioning and depression. Our results indicate that the relationship between family functioning and depression is stronger in women and that acculturative stress moderates this relationship in women. Probing this interaction indicates that women who reported high acculturative stress coupled with poor family functioning experienced more depression. Clinical implications are discussed.  相似文献   
33.
Statistical methods of dimension reduction and classification are used to obtain homogeneous local-area clustering with regard to the most relevant demographic parameters. The dimension reduction is conducted in two stages using Principal Component Analysis and a modified k-mean procedure is proposed to determine the final clusters. This clustering will be useful in future demographic studies at a local level, in particular to obtain forecasts of demographic rates and population projections. The region of Castile and León in Spain is used to illustrate the method. A Poisson model is used to explore the advantages of the new clustering over the more conventional classification based on provinces.  相似文献   
34.
Social Indicators Research - United Nations Development Program presented the Human Development Index for ranking the countries with regard to three dimensions, namely being knowledgeable, a long...  相似文献   
35.
In the present paper we study the framework of additive utility theory, obtaining new results derived from a concurrence of algebraic and topological techniques. Such techniques lean on the concept of a connected topological totally ordered semigroup. We achieve a general result concerning the existence of continuous and additive utility functions on completely preordered sets endowed with a binary operation ``+', not necessarily being commutative or associative. In the final part of the paper we get some applications to expected utility theory, and a representation theorem for a class of complete preorders on a quite general family of real mixture spaces.  相似文献   
36.
Occupational cold exposure is an important risk factor that increases stress at work and can induce many health effects like diseases and symptoms related to cold, including work-related musculoskeletal disorders. The methodological procedures were performed to measure these environmental variables as recommended by the ISO 7726/85. For the analysis of repetitiveness was used the OCRA checklist and evaluation of musculoskeletal morbidity conducted by the Nordic Musculoskeletal Questionnaire. So the objective of this study was to investigate the correlation between cold environmental variables and prevalence of musculoskeletal morbidity in the repetitive work. Was found association between work in cutting and boning sector (occupational cold and repetitive work) and the presence of musculoskeletal morbidity, with a significance of 99%.  相似文献   
37.
38.
Web Survey Design: Paging versus Scrolling   总被引:1,自引:0,他引:1  
A key choice in the design of Web surveys is whether to placethe survey questions in a multitude of short pages or in longscrollable pages. There are advantages and disadvantages ofeach approach, but little empirical evidence to guide the choice.In 2003 we conducted a survey of over 21,000 undergraduate students.Ten percent of the 10,000 respondents were directed to the scrollableversion of the survey, containing a single form for each ofthe major sections. The balance was assigned to the paging version,in which questions were presented to be visible without scrolling.The instrument contained a maximum of 268 possible questions,including topics that varied in sensitivity and desirability.The survey also permitted comparison of the effect of skip patternsby implementing skip instructions and hyperlinks in the scrollabledesign, and also recorded time at the end of each of the fivetopical sections. Differences between designs are evaluatedin terms of various forms of nonresponse, univariate and bivariatemeasurement properties, and proxies for respondent burden.  相似文献   
39.
This study evaluates the role of imperfect competition in determining the agri-food policies impact assessment outcomes. In most impact studies, the supply chain between agricultural production and final consumption is modelled in a perfectly competitive framework. However, there is a growing attention of stakeholders for the presence of imperfectly competitive markets, with the retail sector often being under investigation. This issue is empirically analysed with an application to the dairy industry. First, the degree of market power is estimated using a multi-output demand and price transmission equation system. Then, this model is used for policy simulation with the perfect competition outcome taken as a benchmark to evaluate the impact of imperfect competition. Results show a significant degree of market power in the dairy industry with implications on the projected policy scenarios. Moreover, the imperfect competition model alters the price transmission mechanisms, generating more flexible price trends.  相似文献   
40.
Combining data of several tests or markers for the classification of patients according to their health status for assigning better treatments is a major issue in the study of diseases such as cancer. In order to tackle this problem, several approaches have been proposed in the literature. In this paper, a step-by-step algorithm for estimating the parameters of a linear classifier that combines several measures is considered. The optimization criterion is to maximize the area under the receiver operating characteristic curve. The algorithm is applied to different simulated data sets and its performance is evaluated. Finally, the method is illustrated with a prostate cancer staging database.  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