Measuring and comparing the efficiency of water utility companies: A data envelopment analysis approach

This study provides an analysis of Italian water utilities to determine the effects on their efficiency of certain relevant variables that have been broadly discussed in the existing literature. We reviewed the annual financial statements of 43 Italian water utility companies and obtained other technical data from Co.n.vi.r.i., the Italian national authority for water. Using data envelopment analysis we assessed their cost efficiencies and, using non-parametric statistic methods, we discuss the significant differences among clusters.We found that ownership structure, size and geographical location had an impact on the performance of water utilities, although with different degrees of significance.     

Structural and operational management of Turkish airports: a bootstrap data envelopment analysis of efficiency

This paper explores the structural and operational dimensions of the efficiencies of airports. The two-stage procedure is suggested to assess the efficiencies of airports in this study. In the first-stage, Classification and Regression Tree, which is one of the machine-learning approaches used to divide the airports into homogeneous and thus comparable sub-groups. In the second stage, the bootstrap data envelopment analysis approach obtains more precise structural and operational efficiency scores. To illustrate the proposed framework use, we applied it to a real case associated with Turkish airports. The results demonstrate that this framework presents a more comprehensive assessment of airport performance rather than conventional data envelopment analysis models. Moreover, it provides to show the deficiencies of the structural and operational management of airports. The findings can help anywhere airport authorities as well as Turkish airport authorities.     

Benchmarking the energy efficiency of government buildings with data envelopment analysis

Constructing an indicator to measure the effectiveness of energy management is important for energy agencies and authorities. This paper uses multiple linear regression method and data envelopment analysis to examine the effectiveness of energy management. First, the regression method using environmental factors is used to calculate the predicted energy usage intensity of each evaluated building. Data envelopment analysis is then employed to calculate overall energy efficiency, using the predicted energy usage intensity as output and the observed energy usage intensity as input. Data envelopment analysis can be further applied to measure the overall energy efficiency in details by examining environmental factors and management factors. Finally, the energy consumption of buildings can be measured to evaluate the effectiveness of energy management. Buildings examined as a case study in this paper are government office buildings in Taiwan. The results show that most of the buildings evaluated to report a higher predicted energy usage intensity have successfully used efficient energy management methods in energy saving.     

数据包络分析模型在形成性评价中的应用研究

以南通大学土木工程专业学生的课程学习为例,文章运用数据包络分析模型对学生的学科基础课程学习情况进行形成性评价分析。结果表明,将数据包络分析模型运用到课程学习的形成性评价中,可以帮助学生查找影响自身学习的关键因素,调整学习策略,提高学习效率;还可以帮助教师分析教学过程中存在的问题,探索教学方式方法改革,提升教学水平。     

Performance assessment of the Chilean water sector: A network data envelopment analysis approach

This study applies a two-stage network structure model to evaluate water service providers cost and operational performance embracing service quality variables. An empirical analysis of the Chilean water and wastewater industries over the 2010–2018 period is presented. Moreover, in the second stage of analysis, we analyzed the impact of a set of exogenous variables on the performance of water companies. Results revealed that the Chilean water companies had notable room to reduce costs and improve operational performance. Moreover, it was found that the public water provider performed better than fully private and concessionary water providers.     

Measuring Spanish airport performance: A bootstrap data envelopment analysis of efficiency

This work studies the efficiency of Spanish airports for the year 2018. In the first stage, efficiency is calculated by applying the Data Envelopment Analysis (DEA) method. As inputs, variables have been selected representing the airports' physical aspects, such as the number of boarding gates or the runway area. As outputs, the number of passengers, tons of cargo and the number of operations are included. By means of bootstrapping, it is empirically demonstrated that the airports operated under variable returns to scale. In the second stage, a truncated regression is carried out to determine which variables influence the efficiency of the airports. Previously a bootstrapping with 2000 iterations is applied to correct the possible bias of the DEA results. Airport apron and opening hours are relevant factors to explain the efficiency of airports as well as being a tourist airport.     

基于层次分析法的工程机械管理效率评价

基于层次分析的理论与方法，在工程机械管理效率评价指标体系的基础上，综合考虑评价过程中的定性指标及定量指标，建立合理的综合评价模型，为正确评价与决策提供了科学的方法及手段。     

An integrated approach to analysing the cost efficiency of postal networks

An integrated approach to measure the cost efficiency of the postal network of Universal Service Provider is proposed. An integrated approach enables the measurement of cost efficiency for delivery and non-delivery postal network units. The proposed approach is verified and tested on the postal network of the selected provider and the results were derived by using Data Envelopment Analysis (DEA). The results show that the main sources of inefficiency are inadequate allocation of resources relative to the network units. In addition, the study indicates that economies of scale have a positive impact on the efficiency of postal network units.     

Efficiency measurement of the maintenance of paved lanes using data envelopment analysis

While the road maintenance performance measurement systems that are currently in use investigate maintenance level of service (i.e. effectiveness of the road maintenance), the fundamental relationship between the maintenance level of service and the budget requirements (i.e. the efficiency of road maintenance) has not received as much attention. Given that not knowing how ‘efficient’ transportation agencies are in being ‘effective’ can lead to excessive and unrealistic maintenance budget expectations, there is a need for a performance measurement system that can assess the overall efficiency of road maintenance operations. To address this need, a framework was developed and implemented to assess the relative cost efficiency of eight counties in Virginia, USA in maintaining the paved lanes of the Interstate roads. Such framework is developed using a methodology known as data envelopment analysis which is based on the production theory and principles of linear programming. The results indicate that the Rockbridge County is the most efficient and the Roanoke County is the least efficient in maintaining the paved lanes. The findings of this research are intended to be used as guides for benchmarking as well as managerial actions and policy making for decision making with respect to road maintenance.     

Efficient resource utilization of the electricity distribution sector using nonparametric data envelopment analysis and influential factors

This study aims to investigate the efficient resource utilization of the electricity distribution sector in Pakistan and identifies the influential factors affecting it. In Pakistan, there is excess production capacity and under-utilized power plants, which pose a challenge to the economy due to their burden on the exchequer account and the high power costs. The present study employs the most recent 11 distribution firms panel data from Pakistan for the period 2016–2020 to evaluate the performance ranking of distribution utilities. The study employs standard frontiers, composite indexes, and a novel DEA-windows analysis to measure the efficiency of the distribution utilities. The results of the analysis show that electricity sales, consumer density, and industrial consumers have a positive impact, while distribution losses have a negative association with the efficiency of the distribution utilities. These findings provide valuable insights for policymakers and industry stakeholders in improving the resource utilization and overall performance of the electricity distribution sector. The study highlights the implications of the results in terms of reducing greenhouse gas emissions, which are one of the main contributors to global warming. In conclusion, this study provides an essential contribution to the literature on efficient resource utilization in the electricity distribution sector in Pakistan.     

基于江苏省建筑业效率分析的大学生择业策略研究

运用DEA-SBM模型法,研究江苏省建筑业效率特征,为大学生精准择业提供依据,结果表明：江苏省建筑业综合效率偏低,苏州和南通建筑业生产达到有效;江苏省建筑业无效率主要由产出无效率决定,整体无效现状为大学生发挥专业优势、学以致用提供条件;各地级市建筑业效率水平受纯技术效率或规模效率影响各异,为大学生就业方向提供了多样选择。基于上述研究结果,为满足江苏省建筑业生产效率提高和大学生科学合理择业需求提出对策建议。     

Design of a construction management data visualization environment: A top-down approach

Explored in this paper is the topic of designing a construction management (CM) data visualization environment with emphasis on its use for supporting the time management function during the planning and execution phases of construction projects which are characterized by sizeable volumes of data of different types. A brief overview of recent construction data visualization work is first provided. Then, as part of a top-down design approach, we introduce concepts and useful terminology related to a structured way of thinking about analytical reasoning and visual analytics, and their relationship with construction management functions. The focus of the latter then shifts to how a construction data visualization environment can support project participant analytical reasoning needs for the management of time, specifically planning/predicting and monitoring/diagnosing/controlling construction conditions and time performance. A case study of aspects of an actual project examined using the construction data visualization environment developed to date is then presented. Purposes served include demonstrating the breadth of support that can be offered for reasoning by such an environment, and providing a test case for demonstrating the kind of evaluation process one should engage in to assess how well an environment conforms to the requirements set out for it. Time management functions treated for this case study include assessing quality of a baseline schedule, assessing actual vs. planned construction conditions and time performance, and assessing reasons for deviations. An evaluation of the current environment is then made to assess conformance/non-conformance with the requirements established for it and to identify worthwhile extensions to it. The paper concludes with a discussion of lessons learned from work performed to date, and their application to create a more comprehensive visualization environment that supports multiple CM functions.     

基于LCCA的既有居住建筑节能改造成本效益分析

为了对既有居住建筑节能改造的成本效益问题进行分析,首先运用全寿命周期成本理论分析既有居住建筑节能改造的增量成本与增量效益构成;再运用建筑能耗基本公式推导节能改造增量经济效益测算模型,并通过数学推导证明热源热网节能改造的经济效益要远好于建筑围护结构节能改造的经济效益;最后,运用增量经济效益测算模型和项目经济评价理论对实际案例的成本效益进行分析,计算结果表明:仅进行建筑围护结构节能改造存在投资额大、收益率低的特点,而仅进行热源热网节能改造本身投资收益水平较好。由此可见,建筑围护结构节能改造本身无法吸引社会资金投资,需要政府给予更多的经济激励才能吸引社会资金;而热源热网节能改造在政府适当的经济激励下能够通过市场进行改造资金筹措。     

基于EXCEL的商品混凝土出厂检验的数据管理实践

利用EXCEL超大的电子表格和丰富的计算函数及卓越的数据、图形处理功能制作数据管理模板,从而准确、快速地对繁杂的商品混凝土出厂检验的检验数据进行计算、统计、分析,及时掌握混凝土的质量波动情况,为配合比的调整提供数据依据。该数据管理模板容易学习掌握,具有较强的实用性。     

Influence of available data on sewer inspection program efficiency

One key aspect of sewer inspection programs is the prediction of sewer condition. Despite the development of deterioration models, the influence of available data on models' predictive power has not been studied in depth. In this article, numerical experiments on a semi-virtual asset stock have been conducted to answer two main questions: how to establish a list of the most informative factors and whether it is better to have data imprecision instead of data incompleteness in a utility database. Two approaches for establishing a list of the most informative factors are compared. The results show a statistical analysis (a priori analysis) can predict the impact of available data on inspection program efficiency (a posteriori analysis). This can be used to plan data acquisition programs. Finally, we show that using the notion of “district” (data imprecision) can provide efficient results when the most informative factor “age” is not available (data incompleteness).     

Modelling profitability and effectiveness of Greek-listed construction firms: an integrated DEA and ratio analysis

Existing research on construction performance measurement is dominated by project level studies, and the firm stakeholders require the development of models that compare performance in terms of efficiency. A new framework that integrates data envelopment analysis (DEA) and ratio analysis using a two-step approach is described to evaluate performance in terms of profitability and effectiveness of a sample of construction firms listed on the Athens Exchange. In the first step, profitability and effectiveness are assessed by employing DEA and by using the profit margin (i.e. income-to-sales ratio), respectively. In the second step, a Tobit and an ordinary least squares model are used in order to identify the drivers of profitability efficiency and effectiveness, respectively. Results do point out positive links between profitability efficiency and effectiveness. Profitability inefficiency can be explained by the size and expenses-to-total revenue ratio, whereas effectiveness can be explained only by the latter explanatory variable. The research framework may benefit not only Greek construction firms, but also firms in other countries to quantify their performance and improve their competitive advantages.     

基于AutoCAD的产品数据管理方法研究与实践

提出了产品实体信息与其属性信息相互链接的智能化的产品数据管理方法 ,并利用Au toCAD所提供的ObjectARX2 0 0 0 ,用VisualC ++6 .0语言编程实现 .借助于开放数据库互连 (OD BC)以及MFC类库 ,建立了系统与数据库的通信 ,创建了良好的用户界面     

中国建筑产业效率测度研究:2004～2010

综合运用DEA-BCC和相似SFA方法对2004-2010年中国建筑产业运营效率进行测度。研究发现,中国建筑产业运营效率在此期间呈现稳步增长趋势,除少数省份外,都有不同程度的增长;同时研究验证:地区经济发展水平、建筑产品需求程度和研发投入力度是建筑业有利的外部运营环境因素。     

基于主成分-聚类分析法的建筑节能气候区划

通过分析影响建筑冷热耗量的气候指标,提出了以采暖度日数HDD18、空调度日数CDD26、最冷月平均温度、最热月平均温度、冬季太阳辐射热量、夏季太阳辐射热量、冬季含湿量和夏季含湿量8个气候指标作为建筑节能气候区划指标,采用主成分分析与聚类分析相结合的区划方法对我国270个城市进行了建筑节能气候区划,划分为严寒干热高辐区、严寒凉爽高辐区、严寒无夏区、寒冷微热区、温和炎热湿润区、温和凉爽区和阴冷湿热区,介绍了这7个气候区的主要气候特征和主要的地理范围,明确了各区的建筑节能重点和适宜的技术策略。