Toward a More Accurate Web Service Selection Using Modified Interval DEA Models with Undesirable Outputs

With the growing number of Web services on the internet,there is a challenge to select the best Web service which can offer more quality-of-service(QoS)values at the lowest price.Another challenge is the uncertainty of QoS values over time due to the unpredictable nature of the internet.In this paper,we modify the interval data envelopment analysis(DEA)models[Wang,Greatbanks and Yang(2005)]for QoS-aware Web service selection considering the uncertainty of QoS attributes in the presence of desirable and undesirable factors.We conduct a set of experiments using a synthesized dataset to show the capabilities of the proposed models.The experimental results show that the correlation between the proposed models and the interval DEA models is significant.Also,the proposed models provide almost robust results and represent more stable behavior than the interval DEA models against QoS variations.Finally,we demonstrate the usefulness of the proposed models for QoS-aware Web service composition.Experimental results indicate that the proposed models significantly improve the fitness of the resultant compositions when they filter out unsatisfactory candidate services for each abstract service in the preprocessing phase.These models help users to select the best possible cloud service considering the dynamic internet environment and they help service providers to improve their Web services in the market.

A Range Adjusted Measure of Super-Efficiency in Integer-Valued Data Envelopment Analysis with Undesirable Outputs

DEA(data envelopment analysis) models can be divided into two groups: Radial DEA and non-radial DEA, and the latter has higher discriminatory power than the former. The range adjusted measure(RAM) is an effective and widely used non-radial DEA approach. However, to the best of our knowledge, there is no literature on the integer-valued super-efficiency RAM-DEA model,especially when undesirable outputs are included. We first propose an integer-valued RAM-DEA mode with undesirable outputs and then extend this model to an integer-valued super-efficiency RAM-DEA model with undesirable outputs. Compared with other DEA models, the two novel models have many advantages: 1) They are non-oriented and non-radial DEA models, which enable decision makers to simultaneously and non-proportionally improve inputs and outputs;2) They can handle integer-valued variables and undesirable outputs, so the results obtained are more reliable;3) The results can be easily obtained as it is based on linear programming;4) The integer-valued super-efficiency RAM-DEA model with undesirable outputs can be used to accurately rank efficient DMUs. The proposed models are applied to evaluate the efficiency of China’s regional transportation systems(RTSs) considering the number of transport accidents(an undesirable output). The results help decision makers improve the performance of inefficient RTSs and analyze the strengths of efficient RTSs.

Measuring Environmental Performance of Provincial Thermal Power Plants in China:A Malmquist DEA Approach with Fixed-Sum Undesirable Outputs

With the development of China’s economy,environmental pollution has become cumulatively serious.The primary source of environmental pollution is thermal power generation,which has attracted the attention of governments and academia in recent years.To effectively reduce environmental pollution,research should study how to constrain the undesirable output of thermal power plants,that is,to limit the total undesirable output of the plants to a certain fixed sum.However,few studies have suggested that these undesirable outputs should be fixed-sum outputs.Moreover,no previous research publication about thermal power plants has analyzed their environmental performance changes.To address these gaps,a novel Malmquist-DEA approach is proposed for evaluate the environmental performance of thermal power plants in this paper.This approach generalizes the equilibrium efficient frontier DEA model with fixed-sum undesirable outputs and incorporates the model into the Malmquist productivity index(MPI).The authors apply this approach to the analysis of provincial thermal power plant environmental performance in China and analyze such plants’trends based on panel data from2011 to 2014.The empirical research shows that the environmental performance of regional thermal power plants was positively affected by efficiency change and negatively affected by technical change.Finally,the authors provide policy suggestions based on our findings.

生态文明先行示范区的设立能否提高农业绿色效率?--基于湖南省的经验数据

生态文明先行示范区的设立是生态文明建设过程中的一项重要政策。利用考虑非期望产出的Undesirable Output模型测算了湖南省2007-2016年80个县市的农业绿色效率,采用倾向得分匹配法(PSM)和双重差分法(DID)检验了首批生态文明先行示范区的设立对于农业绿色效率的净效应,研究结果表明:生态文明先行示范区的设立对于农业绿色效率存在显著的正向影响,可以使农业绿色效率增长6.7%,多种稳健性检验均证明了这一提升作用是真实存在的。但是该政策效应存在一段滞后期,且具有一定的持续性,在短期内,作用强度随着时间的推后而不断增强。影响机制检验发现生态文明先行示范区政策主要依靠人力资本来推动农业绿色效率的增长。

Performance Evaluation of Public Bus Transportation by Using DEA Models and Shannon’s Entropy:An Example From a Company in a Large City of China

The purpose of this paper is to assess the operational efficiency of a public bus transportation via a case study from a company in a large city of China by using data envelopment analysis(DEA)model and Shannon’s entropy.This company operates 37 main routes on the backbone roads.Thus,it plays a significant role in public transportation in the city.According to bus industry norms,an efficiency evaluation index system is constructed from the perspective of both company operations and passenger demands.For passenger satisfaction,passenger waiting time and passenger-crowding degree are considered,and they are undesirable indicators.To describe such indicators,a superefficient DEA model is constructed.With this model,by using actual data,efficiency is evaluated for each bus route.Results show that the DEA model with Shannon’s entropy being combined achieves more reasonable results.Also,sensitivity analysis is presented.Therefore,the results are meaningful for the company to improve its operations and management.

Efficiency Analysis of Industrial Water Treatment in China Based on Two-stage Undesirable Fixed-sum Output DEA Model

China is a country with the most water consumption, so it is lack of water resources.Industry has brought serious water pollution while driving economic development, which leads to the destruction of ecological environment. With the improvement of environmental awareness, many scholars have shifted their research direction to how to improve the ecological environment. Most studies consider the whole system as a "black box", regardless of its internal structure. Therefore, a method to identify inefficiency is necessary and some suggestions for optimization are given. In this paper,a two-stage undesirable fixed-sum output data envelopment analysis(DEA) model is proposed. The industrial chemical oxygen demand(COD) emission during 2011–2015 are adjusted, and the efficiency values are calculated by heuristic search algorithm. The efficiency of 30 provinces and cities is divided into eastern, central and western regions. The model can identify the inefficient stage in industrial system, and find the source of low efficiency in the system. The analysis shows that the efficiency of eastern region is the highest, while the overall efficiency is inclined to the pollutant treatment stage.Finally, the paper puts forward some suggestions for the low efficiency areas, which can save water while ensuring economic benefits, and provide new direction for water pollution reduction and improve the ecological environment.

Assessment of Local Public Finance Performance in China When Undesirable Fiscal Phenomena are Taken into Account

Making use of the data envelopment analysis （DEA） technique and taking undesirable fiscal phenomena into account, this paper comprehensively quantifies the public fnance performance of local governments in China during the course of fiscal decentralization reform. The introduction of undesirable fiscal outcomes into this assessment makes it possible to identify meaningful and informative characteristics of local public finance performance in China. When reforms are first implemented, local pubIic financial performance improves because undesirable fiscal phenomena have not yet become too serious. The tax sharing system reform did not work well in its early stages, and negatively impacted public expenditure e3ficiency. The reform started to play a substantial role between 2001 and 2005, when local governments experienced better public finance performance. Corresponding to the deterioration of the financial sector in recent years, local public financial performance worsened after 2007. Further reform of the current fiscal and taxation system is necessary in China, to ensure a brighter future for the nation.

Water resource utilization efficiency and spatial spillover effects in China

Based on provincial panel data of water footprint and grey water footprint, and with the help of data envelopment analysis model considering and without considering the unde- sirable output, this paper estimates the water resources utilization efficiency in China from 1997 to 2011. The spatial weighting matrix based on economy-spatial distance function is established to discuss spatial autocorrelation of water resources utilization efficiency. With the help of absolute/3-convergence model, this paper concludes that there exists/%convergence in the water resources utilization efficiency. Under the conditions of considering and without considering the undesirable output, it takes about 52.6 and 5.6 years respectively to achieve the extent of half of convergence. By mean of the spatial Durbin econometric model, this paper studies spatial spillover effects of the provincial water resources utilization efficiency in China. The results are as follows. 1） With considering and without considering the undesir- able output, there is significant spatial correlation in provincial water resource efficiency in China. 2） Under the two cases, the spatial autoregressive coefficients （p） are 0.278 and 0.507 respectively, at 1% significance level. There exist the spatial spillover effects of provin- cial water resources utilization efficiency. 3） With considering the undesirable output, these factors of the education funds, the transportation infrastructure, and the industrial and agri- cultural water consumption proportion have positive impacts. These factors of foreign direct investment, the industry value-added water consumption per ten thousand yuan, per capita water consumption, and the total precipitation have negative impacts. 4） Without considering the undesirable output, the factor of GDP per laborer has a greater positive significant influ- ence on the water resources utilization efficiency. However the facts of industry value-added water consumption in ten thousand yuan and the transportation infrastructure have no sig- nificant influence. 5） Regardless of undesirable output of water resources utilization efficiency the assessment of the present real water resources utilization in China will be distorted and policy-making will be misled. The water efficiency measure considering environmental factors （such as gray water footprint） is more reasonable.

Productivity Analysis for Banks' Merger and Acquisition Using Two-Stage DEA: Evidence from China

Mergers and acquisitions(M&A) are important parts of banking reform, which can increase the synergies and reduce the costs of the banks. To analyze the effect and importance of the M&A in the reform period, we measure the productivity change of China’s banks who completed M&A during 2004–2018, by using a two-stage data envelopment analysis(DEA) method. First, we incorporate the process of deposits producing and the process of profit earning as a two-stage structure of bank’s system. Then,we construct a slacks-based measure(SBM) model considering the weak disposability of undesirable outputs to measure the productivity of 14 M&A banks in China. Particularly, we adopt the global Malmquist index(GMI) to evaluate the productivity change of the banks, and analyze the efficiency change(EC) and technical change(TC) for the whole system and individual stages. Additionally, to facilitate making M&A plans, we classify the M&A banks to obtain the process they need to improve and the trend they could adopted:(i) We classify them into four categories by the productivity of two individual stages;(ii) We also classify them into four categories by EC and TC. Finally, the policy recommendations for M&A banks are given.

Regional eco-efficiency evaluation and spatial pattern analysis of the Yangtze River Economic Zone

The environmental ecology of the Yangtze River Economic Zone(YREZ)faces ecological function decline,deterioration and degradation under intense human activities,long-term development and utilization and its economy has developed rapidly over recent decades.Eco-efficiency is considered as a measure of coordinated development of economy,resources,environment and ecology,and is currently considered a very important issue.In this paper,based on the slack-based measure and data envelope analysis model,we take 129 prefecture-level cities of the YREZ as the study unit and measure the eco-efficiency of the YREZ in 2000,2005,2010 and 2015,which considers undesired output.The evaluation of the status quo of the regional eco-efficiency development was carried out at provincial,prefectural and city scales.The spatial autocorrelation test model and standard deviation ellipse were used to analyze the spatially distributed characteristics and the evolutionary regularity of eco-efficiency.Our study suggested that the eco-efficiency value varied significantly at different spatiotemporal scales and the overall distribution presented an"N-shaped"pattern,the value is the largest downstream and the smallest upstream.Regional eco-efficiency presented certain volatility in growth and a clear spatial positive agglomeration trend from 2000 to 2015.The spatial distribution of each agglomeration area was also significantly different,forming some high-high agglomeration areas at the center of the shaft with Shanghai and surrounding cities,and some low-low agglomeration areas at the center with middle reaches and upstream cities.The low-high over-aggregation and high-low polarization clusters were fewer.At the same time,with the change of the research period,the degree of positive agglomeration became increasingly pronounced and the eco-efficiency gap of the neighborhoodunit reduced.The regional eco-efficiency value of the YREZ presented a spatial distribution pattern in the northeast-southwest axis and the evolutionary pattern of the regional eco-efficiency similarly showed a northeast-southwest orientation.