September 28, 2017 by Tim Johannessen
Some Impressions from the OR2017 Berlin Conferences Germany


August 31, 2017 by Tim Johannessen
GAMS at OR2017 Berlin Conferences Germany

We are very much looking forward to the OR2017 International Conference on Operations Research which is taking place on September 06-08 in Berlin, Germany.


August 14, 2017 by Tim Johannessen
Scaling Excerpts from Bruce McCarl's Newsletter scaling

Sometimes models do odd things like reporting problems as infeasible, stuck or falsely optimal when scaling is the real issue. To avoid this or correct such issues it is often desirable to check scaling and in turn rescale the model or ask the...


July 27, 2017 by Tim Johannessen
Misbehaving Model – Infeasible Excerpts from Bruce McCarl's Newsletter infeasible artificial variables

Infeasibility is always a possible outcome when solving models. Simplex based linear programming solvers handle infeasibility through a two or three step solution approach. First,there may be some presolution calculations which may determine a model...


September 6, 2016 by Tim Johannessen
GAMS at the OR2016 in Hamburg, Germany Conferences Germany

The German city of Hamburg has a long history in trading and as a port city, and today has the second largest port in Europe. It combines the activity and vibe of a major city, but also has many green and relaxation areas, and in 2016 ranked 10th...