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   25篇
  免费   0篇
计划管理   11篇
经济学   4篇
贸易经济   7篇
经济概况   3篇
  2023年   1篇
  2022年   1篇
  2021年   2篇
  2020年   2篇
  2019年   2篇
  2018年   2篇
  2017年   1篇
  2016年   1篇
  2015年   1篇
  2013年   2篇
  2011年   1篇
  2010年   1篇
  2009年   1篇
  2007年   2篇
  2006年   1篇
  2005年   1篇
  1996年   2篇
  1988年   1篇
排序方式: 共有25条查询结果,搜索用时 704 毫秒
21.
Alcidi  Cinzia  Baiocco  Sara  Corti  Francesco 《Intereconomics》2021,56(3):138-144
Intereconomics - The impact of the COVID-19 pandemic has not been equal across economic sectors, age groups, education levels and employment status.  相似文献   
22.
The paper is a preliminary research report and presents a method for generating new records using an evolutionary algorithm (close to but different from a genetic algorithm). This method, called Pseudo-Inverse Function (in short P-I Function), was designed and implemented at Semeion Research Centre (Rome). P-I Function is a method to generate new (virtual) data from a small set of observed data. P-I Function can be of aid when budget constraints limit the number of interviewees, or in case of a population that shows some sociologically interesting trait, but whose small size can seriously affect the reliability of estimates, or in case of secondary analysis on small samples. The applicative ground is given by research design with one or more dependent and a set of independent variables. The estimation of new cases takes place according to the maximization of a fitness function and outcomes a number as large as needed of ‘virtual’ cases, which reproduce the statistical traits of the original population. The algorithm used by P-I Function is known as Genetic Doping Algorithm (GenD), designed and implemented by Semeion Research Centre; among its features there is an innovative crossover procedure, which tends to select individuals with average fitness values, rather than those who show best values at each ‘generation’. A particularly thorough research design has been put on: (1) the observed sample is half-split to obtain a training and a testing set, which are analysed by means of a back propagation neural network; (2) testing is performed to find out how good the parameter estimates are; (3) a 10% sample is randomly extracted from the training set and used as a reduced training set; (4) on this narrow basis, GenD calculates the pseudo-inverse of the estimated parameter matrix; (5) ‘virtual’ data are tested against the testing data set (which has never been used for training). The algorithm has been proved on a particularly difficult ground, since the data set used as a basis for generating ‘virtual’ cases counts only 44 respondents, randomly sampled from a broader data set taken from the General Social Survey 2002. The major result is that networks trained on the ‘virtual’ resample show a model fit as good as the one of the observed data, though ‘virtual’ and observed data differ on some features. It can be seen that GenD ‘refills’ the joint distribution of the independent variables, conditioned by the dependent one. This paper is the result of deep collaboration among all authors. Cinzia Meraviglia wrote § 1, 3, 4, 6, 7 and 8; Giulia Massini wrote §5; Daria Croce performed some elaborations with neural networks and linear regression; Massimo Buscema wrote §2.  相似文献   
23.
The classic argument for a euro area “fiscal capacity”, understood in this contribution as a centralised fiscal stabiliser, revolves around the need to dampen the effects of asymmetric shocks. According to those preaching this conventional wisdom, a common fiscal stabiliser designed along the lines of the US federal fiscal system would have stabilised incomes in member states hit the hardest, thereby avoiding the divergence that has unfolded in the aftermath of the financial crisis between the South, led by Italy and Greece, and the North, led by Germany and the Benelux countries.  相似文献   
24.
Directional Distance Functions (DDFs) are becoming a popular way of measuring efficiency as they encompass the Shephard output and input distance functions as special cases. However, the most critical and still unsolved issue related to DDF remains the selection of the direction along which to measure the distance from the efficient frontier. In this article, we propose some empirical tools which allow to quantify the sensitivity of the efficiency measurement to the selection of the direction. The proposed tools are applied on a dataset on the Italian agricultural sector.  相似文献   
25.
Quality & Quantity - This work explores the relationship between multinational R&D and innovation productivity among top corporate knowledge and R&D producers by adopting a...  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