DEA model selection is problematic. The estimated efficiency for any DMU depends on the inputs and outputs included in the model. It also depends on the number of outputs plus inputs. It is clearly important to select parsimonious specifications and to avoid as far as possible models that assign full high efficiency ratings to DMUs that operate in unusual ways (mavericks). A new method for mode...

Data envelopment analysis (DEA) is a powerful technique for performance evaluation of decision making units (DMUs). One of the main objectives that is followed in performance evaluation is discriminating among efficient DMUs to provide a complete ranking of DMUs. DEA successfully divides them into two categories: efficient DMUs and inefficient DMUs. The DMUs in the efficient category have ident...

Data envelopment analysis (DEA) is a methodology for measuring the relative efficiencies of a set of decision making units (DMUs) that use multiple inputs to produce multiple outputs. In the conventional DEA, all the data assume the form of specific numerical values. However, the observed values of the input and output data in real-life problems are sometimes imprecise or vague. Previous method...

* Correspondence: mathwy@hit. edu.cn Department of Mathematics, Harbin Institute of Technology, Harbin 150001, People’s Republic of China Abstract In this paper, we introduce the obstacle problem about the nonhomogeneous A-harmonic equation. Then, we prove the existence and uniqueness of solutions to the nonhomogeneous A-harmonic equation and the obstacle problem.

Under various weaker conditions, we establish various results on the existence and nonexistence of positive solutions for singular third-order nonhomogeneous boundary value problems with nonlocal boundary conditions. The arguments are based upon the fixed point theorem of cone expansion and compression. Finally, we give two examples to demonstrate our results. Key–Words: Positive solutions, Fix...

Recently, the concept lattices working with the heterogeneous structures have been fruitfully applied in a fuzzy formal concept analysis. We present a situation under nonhomogeneous formal contexts and explore the bonds in a such nonhomogeneous case. This issue requires to formulate the alternative definition of a bond and to investigate the relationships between bonds and the particular formal...

One way to rank DMUs in DEA is the cross efficiency method. In this method, the efficiencyof each DMU is calculated by other DMUs optimum weights, which makes the ranking moreacceptable for managers. Existing alternative optimum weights in cross efficiency methodlead to several ranks for DMUs. Several secondary goals have introduced to avoid thisproblem, till now. In this paper, a new model is ...

The existence of alternate optima for the DEA weights may reduce the usefulness of the cross-efficiency evaluation, since the ranking provided depends on the choice of weights that the different DMUs make. In this paper, we develop a procedure to carry out the cross-efficiency evaluation without the need to make any specific choice of DEA weights. The proposed procedure takes into consideration...