the performance of a decision making unit (dmu) can be evaluated in either across-sectional or a time-series manner, and data envelopment analysis (dea) is a useful method for both types of evaluation. the malmquist productivity index (mpi) evaluates the change in efficiency of a dmu between two time periods. it is defined as the product of the catch-up and frontier-shift terms. in this paper, ...

In this paper, a new technique has been designed to capture the outline of 2D shapes using cubic B´ezier curves. The proposed technique avoids the traditional method of optimizing the global squared fitting error and emphasizes the local control of data points. A maximum error has been determined to preserve the absolute fitting error less than a criterion and it administers the process of curv...

A method to decompose a 3D object into simple parts starting from its curve skeleton is described. Branches of the curve skeleton are classified as meaningful and non-meaningful by using the notion of zone of influence of the points where skeleton branches meet. Meaningful branches are associated to subsets of the object, which are obtained by subtracting from the input object suitably expanded...