超效率SBM-Malmquist模型在燃气管道完整性管理效能评价中的应用

为解决燃气管道完整性管理效能评价时,无法准确对比各评价单元完整性管理水平的差异,以及无法动态测算同一评价单元完整性管理效能的问题,提出了一种基于超效率松弛值测算(Slacks-Based Measure, SBM)的模型和Malmquist模型相结合的方法,对管道完整性管理效能评价进行研究。首先,综合考虑完整性管理实施过程、效果与效益,并结合专家意见和相关规范标准,构建效能评价指标体系,该指标体系由3项一级指标和14项二级指标进行表征。其次,采用考虑非期望产出的超效率SBM模型解决各评价单元的比较与排序问题,再将Malmquist模型与超效率SBM模型相结合,测算各评价单元效能的动态变化趋势。最后,针对5家燃气公司在2019—2022年的完整性管理效能,采用所提出的效能评价模型开展评价。结果表明,超效率SBM模型和Malmquist模型相结合是实现管道完整性管理效能客观定量评价的有效方法,通过横向对比和动态测度发现短板并提出针对性的改进意见,其分析结果与实际工程相吻合,证明该方法能够有效评估完整性管理效能,为管道完整性管理提供了一种评价思路。

“一带一路”沿线航空运输集团生产效率测度及影响因素

基于2013—2019年“一带一路”沿线航空运输集团的运营面板数据,运用考虑非期望产出的SBM(基于松弛测度)模型和Malmquist-Lenberger指数对各集团生产效率及分解项进行测度,并使用Tobit模型探究生产效率的影响因素。结果表明:沿线生产效率水平偏低,生产效率改善由亚洲地区逐渐分散至各区域,生产效率增长主要来源于技术效率提升;运营更年轻的机队能有效改善生产效率;集团内航空运输子公司过多不利于提升生产效率;宽体机型占比对生产效率影响并不显著。最后,根据研究结果提出相关改进建议。

环境约束下中国与世界主要国家技术效率和生产率的测度与比较

运用含非期望产出的超效率SBM(slack based measure)模型和GML(global Malmquist-Luenberger)指数,对中国与世界主要国家1991—2016年的分别在考虑和不考虑环境约束下的技术效率和全要素生产率进行测度与比较。研究发现,不考虑环境约束的测度结果忽略了一国发展所造成的污染损失,导致技术效率与生产率被高估;中国的技术效率在考虑环境因素后显著下降,总效率排名从样本中的第16位下降至第40位。时间趋势上,中国的环境效率与技术效率的差距呈现先扩大后缩小,且近年来有逐渐趋同的态势;动态视角上,不考虑环境约束时中国的全要素生产率变化总体呈现增长趋势,但在考虑环境因素后中国的环境全要素生产率转变为下降趋势,这其中,技术进步的下降是影响环境全要素生产率变化的主要因素。

中国沿海港口分层效率研究

为对处在不同效率层次的港口制定针对性决策,运用2014—2018年港口群的100个样本数据构建分层SBM-BPNN模型,该模型是基于松弛变量的测量(slack-based measure,SBM)模型与反向传播神经网络(back propagation neural network,BPNN)模型的结合。用构建的模型对2019年的港口群进行效率分层和决策制定。结果表明:分层SBM-BPNN模型不仅可以基于全体决策单元信息对分层SBM模型起替代作用,还可以在信息无法在各港口实时共享时,依据单个港口的信息对港口进行效率层次定位和分层最优决策的制定。分层效率研究有利于港口根据实际资源配置情况制定可行性较高的分阶段决策。

考虑碳排放的长三角机场运营效率研究

传统的机场运营效率研究忽视了非期望产出对机场运营效率的影响,且对有效单元无法进一步排名,基于此,采用长江三角洲16个机场2015~2019年的面板数据,将碳排放量和旅客投诉数量作为非期望产出指标,通过模型对比分析非期望产出的必要性,利用GML(Global Malmquist-Luenberger)指数刻画出机场全要素生产率的时空特性.结果表明,考虑非期望产出后,机场的静态运营效率和动态全要素生产率均产生变化.2015~2019年,长三角机场运营效率呈现波动上升,小型机场受非期望产出影响较大;2015~2019年,长三角机场全要素生产率受技术效率和技术进步共同影响,非期望产出影响技术进步上升的机场数量较多,但是对机场的技术效率影响更大.

Spatiotemporal Differentiation and the Factors Influencing Eco-efficiency in China

Economic development,resource utilization,and environmental protection have always presented clear dilemmas for many countries at the national level.It is clear that the related concepts of eco-efficiency and the evaluation index can help in evaluating these associated issues.Thus,based on the use of undesirable output super Slacks-Based Measure models,this study evaluated the eco-efficiency of 30 Chinese provinces during the period between 2005 and 2016.This evaluation was conducted by analyzing the spatiotemporal dynamics and key factors influencing these changes using a panel regression model.The results of this analysis reveal that eco-efficiency gradually increased over the course of the study period,peaking at different levels among the regions.We used the conventional CV evolutionary method to show that inequalities in eco-efficiency gradually decreased at the national level.Indeed,our estimations of the factors affecting this variable suggest that industrial structure,degree of openness,urbanization,technical innovation,and environmental governance all exert significant positive influences,while energy consumption and traffic exert negative effects.The extent of the impacts of these factors on eco-efficiency varied between the different regions.

Evolution Characteristics of Urban Land Use Efficiency under Environmental Constraints in China

In the context of high-quality economic development and coordinated regional development,this paper measures the urban land use efficiency of 275 prefecture-level cities in China from 2003 to 2016,taking into account the unexpected output(environmental pollution),and explores the temporal and spatial evolution of urban land use efficiency through kernel density estimation and spatial autocorrelation analysis.The results show that:(1)From 2003 to 2016,China’s urban land use efficiency showed an overall fluctuating growth,but it remained at a low level.The mean value of urban land use efficiency has been gradually decreasing in east,west and central regions.(2)In the whole country and the eastern,central and western regions,the regional differences have been increasing,and the efficiency values of the whole country and the east have become polarized.(3)Urban land use efficiency shows a weak spatial positive correlation,but the degree of spatial agglomeration is increasing.High-high agglomeration areas are mostly distributed in the southeastern coastal areas,and extend into the central region,while most of the high-low polarized areas are the capital cities of the central and western regions.The low-high depressed areas are scattered around the high-value accumulation areas,some of which have turned into high-high agglomeration areas during the study period,while the low-low homogeneous areas are mainly distributed in the central,western and northeastern regions.Therefore,it is proposed that strengthening the utilization of urban stock land,strengthening the regional cooperation mechanism,and formulating policies which improve the efficiency of land use are effective ways to promote the intensive and economical use of urban land,as well as regional coordinated development.