排序方式: 共有52条查询结果,搜索用时 31 毫秒
21.
针对枢纽内多个客运站能力利用评价问题,以枢纽内设施能力利用匹配度指标、列车作业组织协调度指标、城市交通接驳适应度指标的耦合计算值定义多个客运站能力利用协调度指标,根据耦合度理论构建基于改进优劣解距离法的枢纽内多个客运站能力利用协调度计算模型,并结合熵权法求解枢纽内多个客运站能力利用协调度。以沈阳铁路枢纽2018年、2019年运行图为例对给出的评价方法进行验证,结果表明:提出的基于改进优劣解距离法的能力利用协调度评价模型可以有效解决枢纽内多个客运站能力利用评价和优化问题,提升运力资源配置效率、减少资源闲置、满足旅客高品质出行体验,为方案比选及预先研判提供技术支持。 相似文献
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在分析IPO盈余管理动机的基础上,研究了IPO公司进行盈余管理的手段及其影响。以2008年在深圳证券交易所上市的71家公司为对象,通过研究其2006-2010五年的经济数据,运用改进后的Jones模型,得出两个结论:上市公司的业绩在IPO前后存在明显的差异,并且上市前两年的业绩高于IPO当年及IPO后两年;上市公司通过调整应计利润进行盈余的操纵。最后针对分析结果提出相应对策,以期对加强证券市场监管,完善公司治理结构,帮助投资者进行投资决策做出贡献。 相似文献
23.
《Food Policy》2017
We analyse the impact of improved chickpea adoption on welfare in Ethiopia using three rounds of panel data. First, we estimate the determinants of improved chickpea adoption using a double hurdle model. We apply a control function approach with correlated random effects to control for possible endogeneity resulting from access to improved seed and technology transfer activities. To instrument for these variables we develop novel distance weighted measures of a household’s neighbours’ access to improved seed and technology transfer activities. Second, we estimate the impact of area under improved chickpea cultivation on household income and poverty. We apply a fixed effects instrumental variables approach where we use the predicted area under cultivation from the double hurdle model as an instrument for observed area under cultivation. We find that improved chickpea adoption significantly increases household income while also reducing household poverty. Finally, we disaggregate results by landholding to explore whether the impact of adoption has heterogeneous effects. Adoption favoured all but the largest landholders, for who the new technology did not have a significant impact on income. Overall, increasing access to improved chickpea appears a promising pathway for rural development in Ethiopia’s chickpea growing regions. 相似文献
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汽车零部件供应商选择方法应用研究 总被引:1,自引:0,他引:1
零部件采购是汽车制造企业供应链管理的重要环节,而供应商的选择是供应链管理的基础。文中将多属性决策理论中的改进TOPSIS法和熵值法的评价优势相结合,引入到汽车零部件供应商选择中来,并以具体的案例说明基于熵值法的改进TOPSIS法是一个可靠、有效且可以持续改善的汽车零部件供应商评价模型,为企业进行供应商选择、管理、监督、改善等活动提供更为有力的依据。 相似文献
25.
The information content of stock splits 总被引:1,自引:0,他引:1
This study examines whether stock splits contain information content about future operating performance or whether splits are undertaken by firms to realign their share prices and to improve trading liquidity. In the four years following split announcements, splitting firms do not experience improved operating performance relative to non-splitting firms. Furthermore, stock split signals are not related to future profitability. The positive announcement effect can be explained by lower share prices and improved market liquidity following stock splits but not by split signals and post-split operating performance. Our results show very little evidence that stock splits signal improvement in long-run operating performance and are more consistent with the trading range/liquidity hypothesis. 相似文献
26.
D.T. Vere 《Agricultural Economics》1998,18(1):63-74
The productivity of improved pastures in Australia's southeastern grazing regions is now believed to be in a state of long-term decline. As yet, there is little economic evidence to support this perception. The analysis reported in this paper seeks to examine improved pasture Productivity change from an economic standpoint in a major Australian grazing area. The analysis rests on the central proposition that the Productivity of the livestock enterprises is a direct reflection of pasture productivity. Using both index number and econometric methods, the results indicate that while the annual growth in livestock and hence, improved pasture productivity has been positive over the period, there has been a significant decline in legume pasture productivity. Because these pastures comprise the bulk of improved pastures, the livestock Productivity of all improved pastures has declined in recent years. In contrast, the growth in livestock productivity from the perennial grass pastures continues to be high. The main reasons for legume pasture livestock productivity decline appear to be various important biological Problems and the long-term decline farmers' terms-of-trade. 相似文献
27.
我国基础专利之改进技术的实施面临诸多障碍,阻碍了改进技术的推广应用,美国司法实践中由法官创设的反向等同原则对于我国解决这一困境具有借鉴意义。对反向等同原则的制度功能与理论基础进行规范分析,并辅以比较法视角,研究发现:反向等同原则不仅可以限制专利字面侵权,平衡专利权人与改进者之间的利益,还可以作为专利政策杠杆,对专利法保护的不同行业技术进行微观调控。确立反向等同原则符合专利契约理论对公平的要求,亦与知识产权工具论的主张相契合。最后,提出建议:以反向等同原则的确立为切入点,使落入专利权利要求字面含义范围内、与专利技术不相等同的全新改进技术免于专利侵权,同时严格把握反向等同原则的适用条件,兼顾基础专利保护与全新改进技术激励。 相似文献
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在1阶段Becker-Grossman模型的基础上,引入日平均降雨量、人均总产出和地域虚拟变量,分析水旱灾害、温度、经济增长和地域差别因素对我国居民能源消费的影响。采用2004年~2011年30个省域数据建立面板模型,研究发现:(1)各省居民基础生活能源消费存在的明显的个体差异,欠发达地区和高海拔地区的生活能源消费基数较高;(2)我国居民能源消费形式已不同于上世纪90年代之前的灾害驱动型,而达到了与发达国家相似的温度驱动型时期,能源消费量与温度关系曲线呈U型,且温度调节的成本差异导致曲线左右不对称;(3)经济增长效应大于温度驱动效应,是近年来我国居民生活能源增加的主要原因,收入能源消费弹性系数仅为0.39,未来能源消费还会进一步增加。最后本文对模型进行了6种形式的扩展,发现模型具有良好的稳健性。 相似文献
30.
针对枢纽内多个客运站能力利用评价问题,以枢纽内设施能力利用匹配度指标、列车作业组织协调度指标、城市交通接驳适应度指标的耦合计算值定义多个客运站能力利用协调度指标,根据耦合度理论构建基于改进优劣解距离法的枢纽内多个客运站能力利用协调度计算模型,并结合熵权法求解枢纽内多个客运站能力利用协调度。以沈阳铁路枢纽2018年、2019年运行图为例对给出的评价方法进行验证,结果表明:提出的基于改进优劣解距离法的能力利用协调度评价模型可以有效解决枢纽内多个客运站能力利用评价和优化问题,提升运力资源配置效率、减少资源闲置、满足旅客高品质出行体验,为方案比选及预先研判提供技术支持。 相似文献