全文获取类型
收费全文 | 441篇 |
免费 | 62篇 |
国内免费 | 1篇 |
专业分类
财政金融 | 45篇 |
工业经济 | 15篇 |
计划管理 | 62篇 |
经济学 | 113篇 |
综合类 | 37篇 |
运输经济 | 9篇 |
旅游经济 | 8篇 |
贸易经济 | 42篇 |
农业经济 | 122篇 |
经济概况 | 51篇 |
出版年
2025年 | 1篇 |
2024年 | 5篇 |
2023年 | 8篇 |
2022年 | 7篇 |
2021年 | 21篇 |
2020年 | 14篇 |
2019年 | 21篇 |
2018年 | 20篇 |
2017年 | 23篇 |
2016年 | 13篇 |
2015年 | 17篇 |
2014年 | 22篇 |
2013年 | 28篇 |
2012年 | 52篇 |
2011年 | 45篇 |
2010年 | 26篇 |
2009年 | 32篇 |
2008年 | 33篇 |
2007年 | 28篇 |
2006年 | 30篇 |
2005年 | 24篇 |
2004年 | 13篇 |
2003年 | 9篇 |
2002年 | 1篇 |
2001年 | 2篇 |
1999年 | 3篇 |
1997年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1986年 | 1篇 |
排序方式: 共有504条查询结果,搜索用时 15 毫秒
481.
482.
《Telecommunications Policy》2018,42(2):116-126
The purpose of this paper is to analyze the characteristics of diffusion process of mobile telephone service and the competitive relationships between mobile and fixed-line services in Guatemalan telecommunications market. We investigated the best-suited model to explain the diffusion process of mobile telephone in Guatemala by estimating diffusion curves using empirical data. Moreover, we explored affecting factors which characterize the diffusion pattern of mobile telephony in Guatemala through statistical analysis. Finally, in order to understand the effects of competition in the diffusion process of Guatemalan mobile phone service, we attempted to clarify the competitive relationship between mobile and fixed-line services using the Lotka-Volterra model. As a result, the logistic model was found to be the best model for describing the diffusion pattern. Moreover, investment in telecommunications, the subscribers of fixed-line services, and the number of operators in mobile market were found as significant determinants of mobile diffusion process. Results from the Lotka-Volterra model showed that the relationship between mobile and fixed-line services has changed from pure competition to amensalism. 相似文献
483.
In the current literature, numerous mortality projection models have been proposed and tested, but in general they have been designed for and applied to mainly ages below 90. As medical advances are being shifted to older ages over time and there is a rapid growth in the number of centenarians, there is a need to expand the modelling to older ages. We propose a logistic two-population mortality projection model for the death rates at ages 80 to 100+ for both sexes. We apply this model and its extensions to high quality old-age mortality data of Belgium, Sweden, Switzerland, and the UK and produce decent model performance in both mortality fitting and forecasting. The model structure also provides a reasonable way to close off the life table, which is supported by both theoretical arguments and empirical evidence. 相似文献
484.
结合股权激励结构这一非财务指标与财务指标构建财务危机预警模型,突破了以往相似研究中只关注财务指标的局限。股权激励是通过一套包括正式或非正式的、内部的或外部的制度或机制来协调公司与所有利害相关者之间的利益关系,以保证公司决策的科学化,从而最终维护公司各方面的利益。因此,本文将反映股权激励的相关研究变量引入财务危机预警模型中,从而全面反映公司状况,以期提高模型预测的全面性与准确性。 相似文献
485.
老年劳动者劳动供给行为的Logistic经验研究 总被引:3,自引:0,他引:3
本文运用青岛市抽样调查数据,通过logistic模型对影响老年劳动者劳动供给行为的因素进行了实证分析,重点研究了养老金对劳动力供给的影响。本文的结论是:第一,我国目前养老金覆盖率低的现状,导致有养老金的劳动者提供更多的劳动力供给,这与养老金同劳动力供给成反向变动的理论假设相违背;第二,实证结果表明,养老金、年龄、性别、技术证书、教育程度对老年劳动者劳动供给行为影响显著。 相似文献
486.
在后勤保障流程建模中。提出了一种将有色Petri网系统、广义随机Petri网系统与面向对象技术、约束理论相结合的流程建模方法,使得模型具有较好的模块性、扩展性。通过应用该方法对军队物资采购机构单元Petri网模型进行着色、赋时、对象化改造,详细说明了该方法的建模步骤。 相似文献
487.
488.
Segmentation of customers by likelihood of repeating business is a very important tool in marketing management. A number of
approaches have been developed to support this activity. This article reviews basic recency, frequency, and monetary (RFM)
methods on a set of data involving the sale of beef products. Variants of RFM are demonstrated. Classical data mining techniques
of logistic regression, decision trees, and neural networks are also demonstrated. Results indicate a spectrum of tradeoffs.
RFM methods are simpler, but less accurate. Considerations of balancing cell sizes as well as compressing data are examined.
Both balancing expected cell densities as well as compressing RFM variables into a value function were found to provide more
accurate models. Data mining algorithms were all found to provide a noticeable increase in predictive accuracy. Relative tradeoffs
among these data mining algorithms in the context of customer segmentation are discussed. 相似文献
489.
关于促进中国商业发展的战略性思考 总被引:6,自引:0,他引:6
随着中国分销领域的全面放开,如何构建一个较为完整的中国商业发展战略成为各界研究的重点。本文从国外商业发展的经验出发,结合中国的实际情况,并建议正确认识商业在国民经济发展中的战略性地位,加强商业统计信息系统的整体建设,强化行业规制和竞争政策的研究,客观评价和正确对待外资进入问题。 相似文献
490.
分析城市建设用地变化影响因素对于探究城市内在演化规律具有十分重要的意义。本文以深圳市为例,通过建立2002~2007年和2007~2012年两个阶段建设用地变化的Logistic回归模型,从空间角度分析了建设用地变化的规律及原因。研究结果表明,在第一阶段(2002~2007年),深圳市处于快速城市化时期,建设用地变化以新增建设用地为主,主要的解释变量是固定资产投资变化,第二产业产值变化,坡度和高程,而在第二阶段(2007~2012年),深圳市进入高度城市化阶段,建设用地变化表现为存量建设用地空间布局的变化,主要解释变量是固定资产投资变化,第二产业产值变化,人均GDP变化和人口密度变化。 相似文献