Summary Operation Research Techniques 1

A snapshot of the summary - Operation Research Techniques 1

• 1 Mathematically modelling

• Give the definition of solution of an optimization problem

  A solution to an optimization problem is a collection of values of the decision variables.
• Give the definition of feasible region of an optimization problem

  The feasible region of an optimization problem is the set of feasible solutions to the problem.
• Give the definition of unbounded problem of an optimization problem

  An optimization problem is unbouded if for any feasible solution x, there exists another feasible solution y whose value is better than the value of x. It has no finite optimal solution.
• Give the definition of infeasible problem of an optimization problem

  A mathematical program is infeasible if there are no feasible solutions. No solution that satisfies all constraints and bounds.
• What is the proportionality assumption of linear programming?

  The assumption that when it takes 3 eggs to make 1 chocolate cake. It takes 9 eggs to make 3 chocolate cakes.
  
  This assumption has to hold to be able to apply linear programming.
• What is meant with the divisibility assumption?

  A variable can be infinitely divisible and still have meaning.
• When are problems called discrete or combinatorial optimization problems?

  When all the variables are binary.
• What is meant with a static and a dynamic model?

  In a static model the decision variables do not involve a sequence of decisions over multiple periods. In a dynamic model the decision variables do involve sequences of decisions over multiple periods.
• What is meant with deterministic and stochastic models?

  In a deterministic problem the value of the objective function and whether or not the constraints are satisfied is known with certainty. Otherwise stochastic.
• What is the isocost line?

  The line on which you can find an optimal solution considering a minimization problem.