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11.
China's transport sector has been attracting great attention for its excessive energy consumption and ever-increasing pollution emissions. Thus, reducing energy intensity is one of the top priorities of China's ongoing transport upgrade. In this paper, by establishing a panel data regression model derived from the Cobb–Douglas cost function, we focus on investigating the impacts of energy price and transport productivity on transport energy intensity at the national and regional levels. The study uses the provincial panel data for 2005–2016 to perform regression analysis. The results show that: (1) energy price has a significantly negative effect on transport energy intensity in the whole China and the eastern region, whereas it has no significant impacts in the central and western China. (2) Improvements in transport productivity can effectively decrease transport energy intensity in the whole China and the three major regions. (3) Applying an extended data envelopment analysis (DEA) approach, we decompose transport productivity into four components (i.e., technical change, technology gap change, scale efficiency change, and pure efficiency change) and further differentiate their impacts in different regions. The results indicate that these four components have substantially different impacts in each region. These results provide some valuable insights for policymakers and enterprise entities aiming to adopt measures to reduce energy intensity and achieve sustainable development in China's transport sector.  相似文献   
12.
We estimate the determinants of capital intensity in Japan and the US, characterized by striking different paths. We augment an otherwise standard Constant Elasticity of Substitution (CES) model with demand-side considerations, which we find especially relevant in the US. In this augmented setting, the elasticity of substitution between capital and labor is placed between 0.74 and 0.90 in Japan, and around 0.30 in the US. We also find evidence of biased technical change, which is capital-saving in Japan but labor-saving in the US. These differences help us explain the diverse experience in the capital deepening process of these economies, and lead us to conclude that demand-side drivers, quite relevant in the US, may also be relevant to account for different growth experiences. A close look at the nature of technological change is also needed before designing one-size-fits-all industrial, economic growth, and/or labor market policies.  相似文献   
13.
从航班计划优化的不同时间阶段分析,可以将航班计划优化分为航班计划静态编排优化、基于航班延误预测的航班计划动态反馈优化和基于机场协同决策(A-CDM)的航班计划动态调整角度三类;进而从航班时刻、机型指派、航班频率等编制环节分析了航班计划静态编排优化;随后利用延误波及预测与数据挖掘预测的优化方法分析了基于航班延误预测的航班计划动态反馈优化的相关研究。最后,根据航班计划优化复杂性分析,给出了航班计划优化的发展趋势和未来研究方向。  相似文献   
14.
To mitigate air traffic demand-capacity imbalances, large European airports implement strategic flight schedules, where flights are assigned arrival/departure slots several months prior to execution. We propose a generic assessment of such strategic schedules using predictions about arrival/departure flight delays and cancellations. We demonstrate our approach for strategic flight schedules in the period 2013–2018 at London Heathrow Airport. Together with the development of dedicated strategic flight schedule optimization models, our proposed approach supports an integrated strategic flight schedule assessment, where schedules are evaluated with respect to flight delays and cancellations.  相似文献   
15.
研究目的:基于2007—2016年26省农业生产数据,测算"面源污染"和"碳排放"两类非期望产出下的农业环境效率,构建"耕地流转—利用规模—利用方式与利用强度—农业环境效率"的传导路径并进行计量检验。研究方法:超效率SBM模型,中介效应模型。研究结果:(1)耕地流转并未显著提高农业环境效率,但耕地利用规模对农业环境效率的影响呈倒U型;(2)耕地流转有助于扩大耕地利用规模,进而在样本中对农业环境效率呈现负向影响。与此同时,耕地流转对农业环境效率也存在正向的直接效应,正负效应基本抵消;(3)耕地利用规模主要通过改变化肥和机械投入强度进而负向影响农业环境效率。研究结论:农业环境效率受耕地流转、利用规模、利用方式和强度等多重因素影响,呈现明显的传导路径,因此,为了提高农业环境效率,在积极推行土地流转和规模化经营政策时,要注意结合地区农业生产力和地理环境,避免盲目扩大经营规模,同时鼓励规模经营主体引进农业绿色环保技术,注重农业生产资料的合理利用。  相似文献   
16.
In many cases, a deficient strategic planning in new companies has led entrepreneurs to take inadequate initial decisions that, in the long term, reflect consequences in the failure of many new businesses. The objective of this article is to propose an executive flight simulator, which will help to identify and evaluate the different development strategies for resources of a new manufacturing company, under the four perspectives of the balanced scorecard, educating the user on the impact that these would have in the main performance indicators. The simulator is designed utilizing the focus of system dynamics to be used didactically in master's degree programs in administration, by entrepreneurs or in executive development programs.  相似文献   
17.
18.
In this paper we consider a reduced-form intensity-based credit risk model with a hidden Markov state process. A filtering method is proposed for extracting the underlying state given the observation processes. The method can be applied to a wide range of problems. Based on this model, we derive the joint distribution of multiple default times without imposing stringent assumptions on the form of default intensities. Closed-form formulas for the distribution of default times are obtained which are then applied to solve a number of practical problems such as hedging and pricing credit derivatives. The method and numerical algorithms presented can be applicable to various forms of default intensities.  相似文献   
19.
于安琪  刘冠坤  杨超 《技术经济》2022,41(4):176-187
基于工业企业数据以及环境统计数据,构建1998-2007年面板数据实证分析出口对企业二氧化硫排放强度的影响。回归结果显示:相较于非出口企业,出口企业二氧化硫排放强度较低;企业出口强度越高时二氧化硫排放强度越低。异质性分析发现:企业所属行业以及企业所在地区差异均会对二氧化硫排放强度产生影响。具体表现为,污染密集型制造业行业中,出口企业比非出口企业更为清洁;相较于其他地区而言,东部地区企业出口对二氧化硫排放强度的降低幅度更为显著。在排除两控区环境规制因素对回归结果的影响,并且通过IV(2SLS)以及PSM-DID等方法处理内生性问题后,本文的回归结果依然稳健。机制分析表明:出口企业一方面通过提高新产品产值——R D,另一方面通过提高全要素生产率,降低了企业的二氧化硫排放强度。此外,通过对企业出口状态的改变(广延边际)和企业出口强度的改变(集约边际)的比较发现,出口企业二氧化硫排放强度低的主要驱动因素在于广延边际而非集约边际。  相似文献   
20.
传统观点认为,股票回购与现金股利存在替代关系,同时在资金约束以及管理层短视情形下,二者对企业中长期研发投资支出产生负向冲击。而“边分红,边研发”却是目前我国上市公司的普遍现象。基于此背景,利用2014-2017年我国A股上市公司样本数据,在迎合渠道下分析股票回购与现金分红行为对研发投资的影响及差异。研究发现:两种分配行为并非具有完全替代性,虽然二者均会通过迎合渠道对研发投资产生正向影响,但迎合渠道又存在差异。其中,现金股利多通过股权融资渠道发挥作用,而股票回购多通过理性迎合渠道发挥作用。  相似文献   
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