The contributions of the paper are threefold: i) compare with mathematical rigour the Charnes, Cooper, and Rhodes DEA model and the Farrell model exhibiting constant returns to scale, ii) reinterpret the contribution of Farrell and Fieldhouse that extended the analysis to variables returns to...

The contributions of the paper are threefold: i) compare with mathematical rigour the Charnes, Cooper, and Rhodes DEA model and the Farrell model exhibiting constant returns to scale, ii) reinterpret the contribution of Farrell and Fieldhouse that extended the analysis to variables returns to...

We have developed a creativity collaboration support system, called GUNGEN, which supports the KJ method. The KJ method is one of the popular idea generation methods in Japan, like brainstorming. This method consists of four steps: entering ideas, grouping ideas, structuring groups, and writing...