26 citations · 58 across the 10 of their papers we have counts for
12 papers
On the convex hull of the graph of a simple monomial
Jon Lee, Daphne Skipper, Emily Speakman
Motivated by previous efforts toward mathematically analyzing the treatment of monomials in spatial branch-and-bound, we study the convex hull of the graph of a simple monomial on…
Volume Formulae for the Convex Hull of the Graph of a Trilinear Monomial: A Complete Characterization for General Box Domains
Lillian Makhoul, Emily Speakman
Solving difficult mixed-integer nonlinear programs via spatial branch-and-bound requires effective convex outer-approximations of nonconvex sets. In this framework, complex problem…
Evacuation Planning on Time-Expanded Networks with Integrated Wildfire Information
Steffen Borgwardt, Nicholas Crawford, Drew Horton +2
We study the problem of evacuation planning for natural disasters, focusing on wildfire evacuations. By creating pre-planned evacuation routes that can be updated based on real-tim…
Hundreds of grocery outlets needed across the United States to achieve walkable cities
Drew Horton, Tom Logan, Daphne Skipper +1
The notion of the -minute city is again popular in urban planning, but the practical implications of developing walkable neighborhoods have not been rigorously explored. What is…
A scalable optimization approach for equitable facility location: Methodology and transportation applications
Drew Horton, Tom Logan, Joshua Murrell +2
Efficient and equitable access to essential services, such as healthcare, food, and education, is an important goal in urban planning, public policy, and transport logistics. Howev…
Gaining or Losing Perspective for Piecewise-Linear Under-Estimators of Convex Univariate Functions
Jon Lee, Daphne Skipper, Emily Speakman +1
We study MINLO (mixed-integer nonlinear optimization) formulations of the disjunction , where is a binary indicator of (),…
Constructing lattice-free gradient polyhedra in dimension two
Joseph Paat, Miriam Schlöter, Emily Speakman
Lattice-free gradient polyhedra can be used to certify optimality for mixed-integer convex minimization models. We consider how to construct these polyhedra for unconstrained model…
Gaining or losing perspective
Jon Lee, Daphne Skipper, Emily Speakman
We study MINLO (mixed-integer nonlinear optimization) formulations of the disjunction , where is a binary indicatorof (), and "…
Computing the volume of the convex hull of the graph of a trilinear monomial using mixed volumes
Emily Speakman, Gennadiy Averkov
Speakman and Lee (2017) gave a formula for the volume of the convex hull of the graph of a trilinear monomial, , over a box in the nonnegative orthant, in terms of the…
On branching-point selection for trilinear monomials in spatial branch-and-bound: the hull relaxation
Emily Speakman, Jon Lee
In Speakman and Lee (2017), we analytically developed the idea of using volume as a measure for comparing relaxations in the context of spatial branch-and-bound. Specifically, for…
Experimental validation of volume-based comparison for double-McCormick relaxations
Emily Speakman, Han Yu, Jon Lee
Volume is a natural geometric measure for comparing polyhedral relaxations of non-convex sets. Speakman and Lee gave volume formulae for comparing relaxations of trilinear monomial…
Quantifying Double McCormick
Emily Speakman, Jon Lee
When using the standard McCormick inequalities twice to convexify trilinear monomials, as is often the practice in modeling and software, there is a choice of which variables to gr…