We present a simple algorithm for the Level Ancestor Problem. A Level Ancestor Query LA(v; d) requests the depth d ancestor of node v. The Level Ancestor Problem is to preprocess a given rooted tree T to support level ancestor queries. While optimal solutions to this problem already exist, our new optimal solution is simple enough to be taught and implemented. c © 2003 Elsevier B.V. All rights ...

Some recent works in machine learning and computer vision involve the solution of a bilevel optimization problem. Here the solution of a parameterized lower-level problem binds variables that appear in the objective of an upper-level problem. The lower-level problem typically appears as an argmin or argmax optimization problem. Many techniques have been proposed to solve bi-level optimization p...

Computing the exact ideal and nadir criterion values is a very ‎important subject in ‎multi-‎objective linear programming (MOLP) ‎problems‎‎. In fact‎, ‎these values define the ideal and nadir points as lower and ‎upper bounds on the nondominated points‎. ‎Whereas determining the ‎ideal point is an easy work‎, ‎because it is equivalent to optimize a ‎convex function (linear function) over a con...

In this paper, we formulate the elevator dispatching problem as a stochastic bilevel optimization problem, where a group of elevators serves a set of transportation requests. In the upper level, the requests are assigned to the elevators. In the lower level, the route for each elevator is solved separately. The lower level problem predicts the optimal system state for a finite planning horizon ...