Overall Efficiency and its Decomposition in a Two-Stage Network DEA Model

This paper aims to propose a new approach to decompose an overall data envelopment analysis model into equivalent two-stage models.In this approach,we use a minimax reference point method to set the weights and reliabilities of the two stage models so that the combined efficiency of the two stages is equal to the overall efficiency.The equivalent multi-stage models are useful to support planning for performance improvement.An illustrative example is first explored to compare the results from the new approach with those of four other existing approaches.The main finding from the comparisons is that the new decomposition approach of this paper satisfies the proposed assumptions.A case study is then conducted on a two-stage process of steel manufacturing to illustrate the validity and applicability of the proposed approach.

Dual-radiation-chamber coordinated overall energy efficiency scheduling solution for ethylene cracking process regarding multi-parameter setting and multi-flow allocation

Ethylene cracking process is the core production process in ethylene industry,and is paid more attention to reduce high energy consumption.Because of the interdependent relationships between multi-flow allocation and multi-parameter setting in cracking process,it is difficult to find the overall energy efficiency scheduling for the purpose of saving energy.The traditional scheduling solutions with optimal economic benefit are not applicable for energy efficiency scheduling issue due to the neglecting of recycle and lost energy,as well as critical operation parameters as coil outlet pressure(COP)and dilution ratio.In addition,the scheduling solutions mostly regard each cracking furnace as an elementary unit,regardless of the coordinated operation of internal dual radiation chambers(DRC).Therefore,to improve energy utilization and production operation,a novel energy efficiency scheduling solution for ethylene cracking process is proposed in this paper.Specifically,steam heat recycle and exhaust heat loss are considered in cracking process based on 6 types of extreme learning machine(ELM)based cracking models incorporating DRC operation and three operation parameters as coil outlet temperature(COT),COP,and dilution ratio according to semi-mechanism analysis.Then to provide long-term decision-making basis for energy efficiency scheduling,overall energy efficiency indexes,including overall output per unit net energy input(OONE),output-input ratio per unit net energy input(ORNE),exhaust gas heat loss ratio(EGHL),are designed based on input-output analysis in terms of material and energy flows.Finally,a multiobjective evolutionary algorithm based on decomposition(MOEA/D)is employed to solve the formulated multi-objective mixed-integer nonlinear programming(MOMINLP)model.The validities of the proposed scheduling solution are illustrated through a case study.The scheduling results demonstrate that an optimal balance between multi-flow allocation,multi-parameter setting,and DRC coordinated operation is reached,which achieves 3.37%and 2.63%decreases in net energy input for same product output and conversion ratio,as well as the 1.56%decrease in energy loss ratio.

Land and Water Use in Rice-upland Crop Rotation Areas in Lower Ili River Basin, Kazakhstan

The lower Ili River Basin is located in semi-arid area, and the annual rainfall is 177mm. Therefore, the irrigation is inevitable for agriculture. Large-scale irrigated agriculture had been developed since 1960＇s in the lower parts of the river and the total irrigated area is about 32 000 hm2. In the project area, the paddy rice-upland crop rotation has been practiced. Due to the domestic water use for hydropower and agriculture as well as water use among riparian countries, the deficit of water for agriculture in the lower part has been concerned. The authors, therefore, conducted the field survey and water balance analysis of the Akdara irrigation project in the lower Ill River Basin in order to assess the land and water uses. Moreover, the impact of the water use on water environment to the basin was analyzed. The following results were obtained as following （1） the groundwater level in the irrigated district varied from 1.5 m to 3.5 m through year. （2） 1970＇s groundwater level was drastically raised from 8 m to 3 m and the groundwater had been recharged in this period. （3） Water use efficiency of agriculture, which is the ratio of total evapotranspiration to the total water withdrawal was as low as 0.23.

Modelling overall transmitted efficiency at 1550 nm for polymer grating Silicon-on-insulator structure with defect

The overall transmitted efficiency at 1550 nm for Nylon-Teflon/Teflon-Nylon （N-T/T-N） grating Silicon- on-insulator （SOI） structure with defect in even and odd position was investigated in this paper. Different types of losses, such as absorption, reflection and diffraction, were considered to find out the overall transmitted efficiency. The absorption loss of both Nylon-Teflon （N-T） and Teflon-Nylon （T-N） structure is zero at the wavelength of 1550 nm. Reflectance of these structures was analyzed by using plane wave expansion （PWE） method. Simulation result showed that reflectance as well as transmittance was varied linearly with respect to defect at odd and even positions. Simulation is also done for the diffraction efficiency at 1550nm with respect to detuning from Bragg＇s angle, which was ranged from -0.4 rad to ＋ 0.4 rad. Finally, it was found that overall transmitted efficiency increased as even defect position varied from 2nd to 10th for both N-T/T-N grating SOI structure. Similarly, the overall transmitted efficiency decreased as odd defect position changed from 3rd to l lth for both N-T/T-N grating SOI structure.

Investigating Overall Technical Efficiency in China Commercial Banks： a DEA Approach

Based on the non-Archimedian infinite model C^2R of the Data Envelopment Analysis, combined with characteristics of Chinese mainland banks＇ inputs and outputs, the paper sets up an index system of inputs and outputs as well as an overall technical efficiency evaluation model for Chinese banks, which considers not only the profit ability, but also the control capacity of banks risk. The overall technical efficiency values of Chinese banks are given respectively based on the samples of state owned banks and 14 integrated samples both state owned banks and shareholding banks. The input redundancy of labor, net value fixed assets, operating expenses, owner＇s equity, branch number and output deficiency of operating income, total increase in deposits, total increase in loans, ROE, decrease in bad debts ratio, are also calculated. The pertinence policy suggestions of efficiency improvement of banks are put forward. The results show that the efficiencies of new shareholding banks are far higher than non-shareholding bank and the all four state owned banks are commonly lower in overall technical efficiency. The overall technical efficiency of Agriculture Bank of China is the lowest one in all banks, and Bank of Communications is the efficiency lowest in all shareholding banks. The contributions and characteristics of the paper are： 1） the bad debit ratio is used to reflect the quality of the outputs, which is an improvement to the current literature of neglecting the difference in loans quality. 2） The inefficiency reasons of banks are list out by quantity analysis, and the pertinent macro strategies and concrete measures on improving banks efficiency are given, which is another improvement to current research that tend to give the efficiency value, but not ignore giving improving strategy from quantities analysis. 3） Banks overall technical efficiency values under several portfolios of inputs and outputs are given respectively, which not only overcomes the restraints that the sample size is at least the 2 times of the number of inputs and outputs indexes, but also measures banks overall technical efficiency from several directions. 4） It makes the efficiency values estimation more comparable by extracting four state owned banks for another efficiency evaluation. Combining both state owned banks and shareholding banks as a whole group of efficiency evaluation shows the real overall technical efficiency distance between two different kinds of bank and provide realistic basis for the bank reform of China.

Assessing Textile Factory Performance

This paper provides a way of assessing performance in for-profit sectors, such as, textile factories of Nanjing Textiles Corporation, China. The methods are closely related to the Farreal efficiency measure or data envelopment analysis (DEA). The paper studies the following three problems: (1) whether factory is operating at the minimum point of the long-run average cost curve; (2) whether there exists costless reduction in input; and (3) whether factory happens input congestion. The results show that the economic efficiency of textile factories in 1989 was worse than that in 1988, and different economic systems, state ownership and collective ownership may lead to distinct performances.

Prognostication of energy indices of tractor-implement utilizing soft computing techniques

Energy indices(energy requirement for tillage implement(ERTI)and tractor overall energy efficiency(TOEE))of tractor-implement during tillage operations were aimed to be investigated in this study.To generate a new comprehensive model,the effects of forward speed at three levels(2,4 and 6 km/h)and plowing depth at three levels(10,20 and 30 cm)on energy indices were experimentally evaluated.Two soft computing techniques,artificial neural network(ANN)and adaptive neuro-fuzzy inference system(ANFIS),were employed to prognosticate energy indices.Comparison between the best developed structure of each soft computing technique demonstrated that one comprehensive ANN model was preferred than two individual ANFIS models.According to the ANN prognostication results,simultaneous increase of forward speed from 2 to 6 km/h along with plowing depth increment from 10 to 30 cm led to nonlinear increment of the ERTI and TOEE from 33.87 to 122.66 MJ/ha and 4.65 to 17.85%,respectively.Moreover,interaction of forward speed and plowing depth on energy indices was congruent.Development of comprehensive ANN model now makes it possible to answer fundamental questions in domain of the effect of plowing depth and forward speed on energy indices of tractor-implement that were previously intractable.Hence,to properly manage energy indices and reduce energy dissipation of tractor-implement,application of the new developed ANN model is strongly recommended.