74 citations · 140 across the 17 of their papers we have counts for
18 papers
Optimal Trajectory Planning for Space Object Tracking with Collision-Avoidance Constraints
Saif R. Kazi, Harsha Nagarajan, Hassan Hijazi +1
A control optimization approach is presented for a chaser spacecraft tasked with maintaining proximity to a target space object while avoiding collisions. The target object traject…
Bound Tightening using Rolling-Horizon Decomposition for Neural Network Verification
Haoruo Zhao, Hassan Hijazi, Haydn Jones +3
Neural network verification aims at providing formal guarantees on the output of trained neural networks, to ensure their robustness against adversarial examples and enable their d…
Benchmarking Large-Scale ACOPF Solutions and Optimality Bounds
Smitha Gopinath, Hassan L. Hijazi
We present the results of a comprehensive benchmarking effort aimed at evaluating and comparing state-of-the-art open-source tools for solving the Alternating-Current Optimal Power…
Globally Optimal Boresight Alignment of UAV-LiDAR Systems
Smitha Gopinath, Hassan L. Hijazi, Adam Collins +5
In airborne light detection and ranging (LiDAR) systems, misalignments between the LiDAR-scanner and the inertial navigation system (INS) mounted on an unmanned aerial vehicle (UAV…
Verifying Global Optimality of Candidate Solutions to Polynomial Optimization Problems using a Determinant Relaxation Hierarchy
Sikun Xu, Ruoyi Ma, Daniel K. Molzahn +2
We propose a method for verifying that a given feasible point for a polynomial optimization problem is globally optimal. The approach relies on the Lasserre hierarchy and the resul…
Disjunctive linear separation conditions and mixed-integer formulations for aircraft conflict resolution
Fernando H. C. Dias, Hassan Hijazi, David Rey
We address the aircraft conflict resolution problem in air traffic control. We introduce new mixed-integer programming formulations for aircraft conflict resolution with speed, hea…
Proving Global Optimality of ACOPF Solutions
S. Gopinath, H. L. Hijazi, T. Weisser +4
We present our latest contributions in terms of mathematical modeling and algorithm development for the global optimization of the ACOPF problem. These contributions allow us to cl…
Convex Hull Formulations for Mixed-Integer Multilinear Functions
Harsha Nagarajan, Kaarthik Sundar, Hassan Hijazi +1
In this paper, we present convex hull formulations for a mixed-integer, multilinear term/function (MIMF) that features products of multiple continuous and binary variables. We deve…
Juniper: An Open-Source Nonlinear Branch-and-Bound Solver in Julia
Ole Kröger, Carleton Coffrin, Hassan Hijazi +1
Nonconvex mixed-integer nonlinear programs (MINLPs) represent a challenging class of optimization problems that often arise in engineering and scientific applications. Because of n…
Exploiting sparsity for the min k-partition problem
Guanglei Wang, Hassan Hijazi
The minimum k-partition problem is a challenging combinatorial problem with a diverse set of applications ranging from telecommunications to sports scheduling. It generalizes the m…
Invex Optimization Revisited
Ksenia Bestuzheva, Hassan Hijazi
Given a non-convex optimization problem, we study conditions under which every Karush-Kuhn-Tucker (KKT) point is a global optimizer. This property is known as KT-invexity and allow…
Complex Number Formulation and Convex Relaxations for Aircraft Conflict Resolution
David Rey, Hassan Hijazi
We present a novel complex number formulation along with tight convex relaxations for the aircraft conflict resolution problem. Our approach combines both speed and heading control…
Strengthening the SDP Relaxation of AC Power Flows with Convex Envelopes, Bound Tightening, and Lifted Nonlinear Cuts
Carleton Coffrin, Hassan Hijazi, Pascal Van Hentenryck
This paper considers state-of-the-art convex relaxations for the AC power flow equations and introduces new valid cuts based on convex envelopes and lifted nonlinear constraints. T…
Efficient Dynamic Compressor Optimization in Natural Gas Transmission Systems
Terrence W. K. Mak, Pascal Van Hentenryck, Anatoly Zlotnik +2
The growing reliance of electric power systems on gas-fired generation to balance intermittent sources of renewable energy has increased the variation and volume of flows through n…
Polynomial SDP Cuts for Optimal Power Flow
Hassan Hijazi, Carleton Coffrin, Pascal Van Hentenryck
The use of convex relaxations has lately gained considerable interest in Power Systems. These relaxations play a major role in providing global optimality guarantees for non-convex…
Network Flow and Copper Plate Relaxations for AC Transmission Systems
Carleton Coffrin, Hassan L. Hijazi, Pascal Van Hentenryck
Nonlinear convex relaxations of the power flow equations and, in particular, the Semi-Definite Programming (SDP), Convex Quadratic (QC), and Second-Order Cone (SOC) relaxations, ha…
DistFlow Extensions for AC Transmission Systems
Carleton Coffrin, Hassan L. Hijazi, Pascal Van Hentenryck
Convex relaxations of the power flow equations and, in particular, the Semi-Definite Programming (SDP), Second-Order Cone (SOC), and Convex DistFlow (CDF) relaxations, have attract…
The QC Relaxation: Theoretical and Computational Results on Optimal Power Flow
Carleton Coffrin, Hassan L. Hijazi, Pascal Van Hentenryck
Convex relaxations of the power flow equations and, in particular, the Semi-Definite Programming (SDP) and Second-Order Cone (SOC) relaxations, have attracted significant interest…