While mixed integer linear programming (MILP) solvers are routinely used to solve a wide range of important science and engineering problems, it remains challenging task for end users write correct efficient MILP constraints, especially problems specified using the inherently non-linear Boolean logic operations. To overcome this challenge, we propose syntax guided synthesis (SyGuS) method capab...

This study investigates the progress made in lp and milp solver performance during last two decades by comparing software from beginning of millennium with codes available today. On average, we found out that for solving lp/milp, computer hardware got about 20 times faster, algorithms improved a factor nine around 50 milp, which gives total speed-up 180 1,000 times, respectively. However, these...

A railway timetable is typically planned one year in advance, but may be revised several times prior to the time of operation in order to accommodate on-demand slot requests for inserting additional trains and network maintenance. Revising timetables is a computationally demanding task, given the many dependencies and details to consider. In this paper, we focus on the potential of using optimi...

design of a logistics network in proper way provides a proper platform for efficient and effective supply chain management. this paper studies a multi-period, multi echelon and multi-product integrated forward-reverse logistics network under uncertainty. first, an efficient complex mixed-integer linear programming (milp) model by considering some real-world assumptions is developed for the inte...

A standard approach to solve Mixed Integer Linear Programs is to perform a global branch and bound search through all possible combinations. Due to the hardness of the problem, this search must be closely controlled by a constraint solver which uses constraints to prune the search space in an a priori way. In this paper, we deene a new domain reduction solver which uses in a cooperative way a s...

Long-Reach Passive Optical Network (LR-PON) using hybrid TDM/WDM techniques is one of the candidates for the future optical access that can solve the expected increase in terms of traffic demand and area coverage. One of its advantages is the possibility to share the capacity of any wavelength among more than one user, through TDM/WDM hybrid multiplexing. However, it is still an open issue whic...

SYMPHONY is a customizable, open-source library for solving mixed-integer linear programs (MILP) by branch, cut, and price. With its large assortment of parameter settings, user callback functions, and compile-time options, SYMPHONY can be configured as a generic MILP solver or an engine for solving difficult MILPs by means of a fully customized algorithm. SYMPHONY can run on a variety of archi...

Amethod for Ž nding fuel-optimal trajectories for spacecraft subjected to avoidance requirements is introduced. These include avoidance of collisions with obstacles or other vehicles and prevention of thruster plumes from one spacecraft impinging on another spacecraft. The necessary logical constraints for avoidance are appended to a fuel-optimizing linear programby including binary variables i...