In data envelopment analysis, methods for constructing sections of the frontier have been recently proposed to visualize the production possibility set. The aim of this paper is to develop, prove and test the methods for the visualization of production possibility sets using distributed computations. In this article a general scheme of the algorithm for constructing sections (visualization) of ...

Clouds are a concept for uncertainty mediating between the concept of a fuzzy set and that of a probability distribution. A cloud is to a random variable more or less what an interval is to a number. We discuss the basic theoretical and numerical properties of clouds, and relate them to histograms, cumulative distribution functions, and likelihood ratios. We show how to compute nonlinear transf...

The paper starts from the standard relational view linking objects and properties in formal concept analysis, here augmented with four modal-style operators (known as sufficiency, dual sufficiency, necessity and possibility operators). Formal concept analysis is mainly based on the first operator, while the others come from qualitative data analysis and can be also related to rough set theory. ...

The indicator of groundwater contamination developed and used in agriculture is calculated from data available in the field or data estimated by an expert. The modeling of this indicator generally requires a large number of parameters whose measure is imprecise. Several information sources provide information about the same imprecise quantities which have to be combined for defining what is cal...

Efficient handling of inexact (grey) information is an important issue for the new emerging database technology. Inexact or imprecise information has been represented and manipulated by using different techniques, including fuzzy set theory, possibility theory, IVF (Interval Valued Fuzzy) Sets, Time Petri Nets, Fuzzy Clouds, etc. In this paper, different approaches dealing with uncertainty have...

In this contribution a representation of imperfect spatial information is proposed based on linguistic qualifiers within fuzzy set theory and possibility theory. By adopting a Fuzzy Object Oriented Database approach new data types for representing geographic entities characterized by either unsharp boundaries or indeterminate boundaries and relationships are defined. Finally, the evaluation mec...

in this paper, weak defining hyperplanes and the anchor points in dea, as an important subset of the set of extreme efficient points of the production possibility set (pps), are used to construct unobserved dmus and in the long run to improve the envelopment of all observed dmus. there has been a surge of articles on improving envelopment in recent years. what has been done first is in constant...

  Data envelopment analysis (DEA) is a non-parametric method for assessing relative efficiency of decision-making units (DMUs). Every single decision-maker with the use of inputs produces outputs. These decision-making units will be defined by the production possibility set. Resource allocation to DMUs is one of the concerns of managers since managers can employ the results of this process to a...

Uncertain input parameters may result from "fuzziness", "randomness" or "fuzzy randomness". With the use of fuzzy set theory, uncertain input parameters may be described mathematically as fuzzy variables or fuzzy random variables and may be integrated into safety assessment analysis. With the aid of -discretization involving the multiple solution of special optimization problems, fuzzy input pa...