Optimization Final Exam Flashcards
Any specifcation of the decision variables that satisfies all of the model’s constraints.
Feasible Region
Any point in the feasible region.
Feasible Point
A line on which all points have the same z-value in a max problem.
Isoprofit Line
A line on which all points have the same z-value in a min problem.
Isocost Line
If the LHS and RHS of a constraint are equal when the optimal values of the decision variables are substituted into the constraint.
Binding Constraint
If the LHS and RHS of a constraint are unequal when the optimal values of the decision variables are substituted into the constraint.
Nonbinding Constraint
If the line segment joining any pair of points in S is wholly contained in S.
Convex Set
If each line segment that lies completely in S and contains the point P has P as an endpoint of the line segment.
Extreme Point
There are points in the feasible region with arbitrarily large z - values.
Unbounded LP
The feasible region contains no points.
Infeasible LP
Two or more extreme points are optimal, and the LP will have an infinite number of optimal solutions.
Multiple Optimal Solutions
A variable that appear with a coefficient of 1 in a single equation and a coefficient of 0 in all other equations.
Basic Variable
Any solution to the system Ax=b in which all variables are nonnegative.
Basic Feasible Solution
For any LP with m constraints, if its set of basic variables have m-1 basic variables in common.
Adjacent Basic Solutions
If there is no nonbasic variables with a zero coefficient in row 0 of the optimal tableau.
Unique Solution
In an optimal tableau, there exists a NBV with coefficient zero in row 0, and continuing the Simplex algorithm will obtain another optimal tableau with a different solution.
Alternative Optimal Solution
When a variable with a negative coefficient in row 0 has a nonpositive coefficient in each constraint.
Unbounded LP
If an LP has at least one BFS in which a basic variable is equal to zero.
Degenerate LP
The artificial variable remains positive in the final tableau.
Infeasible LP
Let x = [x1, x2, … xn] be any feasible solution to the primal and y = [y1, y2, … yn] be any feasible solution to the dual. Then (z-value for x) <= (w-value for y).
Weak Duality
If the primal LP has an optimal solution, then its dual also has an optimal solution, and the optimal values of their objective functions are equal.
Strong Duality
Unbounded Primal
Dual Infeasible
Unbounded Dual
Primal Infeasible
If the primal has an optimal solution, then the dual has an optimal solution. Also z = w.
The Dual Theorem
The amount by which the optimal z-value is improved if we increase bi by 1.
Shadow Price
What’s true about shadow price?
The shadow price of the ith constraint of a max problem = the optimal value of the ith dual variable.
Ensures that the total quality produced does not exceed plant capacity.
Supply Constraint
Ensures that a location receives its demand.
Demand Constraint
The LP obtained by omitting all integer or 0-1 constraints on variables.
LP Relaxation