Applications – OR and Management Sciences

A Lifting-and-Splitting Framework for Risk-Averse Distributionally Robust Multi-Item Newsvendor Problems

Categories Robust Optimization, Semi-definite Programming, Supply Chain Management

Risk-averse distributionally robust multi-item newsvendor problems provide a fundamental model for inventory decisions under demand uncertainty, limited distributional information, and downside-risk concerns. We study this problem under mean-covariance demand ambiguity, where the decision maker maximizes the worst-case conditional value-at-risk of profit. While cross-item demand correlations are important for portfolio-level inventory decisions, they are difficult to … Read more

A Numerically-safe Branch-Price-and-Cut Algorithm for the Length-Constrained Cycle Partition Problem

Categories (Mixed) Integer Linear Programming, Applications - OR and Management Sciences, Dynamic Programming Tags , , , ,

The length-constrained cycle partition problem (LCCP) is a graph optimization problem in which a set of nodes must be partitioned into a minimum number of cycles. Every node is associated with a critical time and the length of every cycle must not exceed the critical time of any node in the cycle. We formulate LCCP … Read more

Integrating Power Profile Optimization with Timetabling for Underground Train Networks

Categories (Mixed) Integer Linear Programming, Polyhedra, Transportation Tags , , ,

We study energy-efficient operation of underground train networks by integrating power profile optimization with timetable design in a single mixed-integer optimization framework. The model minimizes traction energy by synchronizing braking and acceleration across trains sharing a power subnetwork to exploit regenerative energy and flexibly allocating running times to promote coasting. Unlike timetable-only approaches with fixed … Read more

Random-Key Optimization for 2D Irregular Packing with Reusable Area Evaluation

Categories Applications - OR and Management Sciences, Meta Heuristics, Parallel Algorithms, Production and Logistics Tags , ,

The diverse constraints of industrial applications lead to variants of 2D irregular packing problems that require tailored solution methods. This paper addresses a real-world industrial challenge by proposing a new problem definition, the Maximum Reusable Contiguous Area Problem (MRCAP), and a novel metric, the Maximum Contiguous Area, developed to measure and maximize the contiguous unused … Read more

A Dynamic-Programming Labeling Approach to Hydrogen-Powered Route Selection in Aviation Networks

Categories Airline Optimization, Applications - OR and Management Sciences Tags , ,

We study passenger routing in an aviation network that blends hydrogen‐ and kerosene‐powered aircraft. Under our assumptions, hydrogen enables carbon‐free short‐ and medium‐haul flights but requires capital‐intensive supply facilities, which lead to varying prices and availabilities of hydrogen at specific airports, creating strong interdependencies between routing, technology choice, and infrastructure availability. To capture these trade‐offs, … Read more

Route `Em and Count `Em: A Two-Stage Stochastic Programming Model for Anti-Submarine Operations

Categories (Mixed) Integer Linear Programming, Stochastic Programming, Transportation Tags , , ,

Tracking targets in undersea warfare requires successful detection by an active search asset. Maximizing detection likelihood requires strategic placement and routing of the search assets in the search region over the planning horizon. We develop a two-stage stochastic integer programming model that maximizes the expected total reward for target detections under uncertainty in target motion … Read more

GPU-accelerated superiorization on constrained physical problems with SupPy

Categories Applications - OR and Management Sciences, Biomedical Applications, Constrained Nonlinear Optimization Tags , , , , ,

The superiorization method (SM) is situated between feasibility-seeking and constrained optimization. Instead of aiming at the minimum of a given objective function over a constraint set, it seeks a feasible point at which the objective function value is reduced — though not necessarily minimal — compared to that reached by the feasibility-seeking algorithm alone. This … Read more

Spatial Optimization Models for Width-Constrained Wildlife Corridor Design

Categories (Mixed) Integer Linear Programming, Applications - OR and Management Sciences, Applications - Science and Engineering Tags , , ,

Human activities increasingly fragment natural habitats, placing many species at risk of population decline. This creates an urgent need to preserve biodiversity and maintain ecological connectivity through wildlife corridors. We present two spatial optimization models for corridor design that explicitly incorporate corridor width as a key ecological criterion. The first model minimizes total corridor cost … Read more

Skip or Insert? A Priori Optimization for the Vehicle Routing Problem with Time Windows and Stochastic Customers

Categories Combinatorial Optimization, Production and Logistics, Stochastic Programming Tags , , , , , , ,

We study an extension of the vehicle routing problem with time windows by incorporating stochastic customers, i.e., ad-hoc service requests. The uncertainty in stochastic customers is captured through scenarios. Two a priori optimization approaches, a classical and a new one lead to two different problems, both of which are modeled as scenario-based two-stage stochastic programs. … Read more

Neural Assortment Optimization

Categories Combinatorial Optimization, Nonsmooth Optimization, Yield Management

Assortment optimization selects a subset of items to maximize expected revenue under a discrete choice model and is widely used in revenue management and online platforms. Its combinatorial nature creates a practical tension among generality, scalability, and provable guarantees: model-specific algorithms can be strong when their structural assumptions hold, but are hard to adapt across … Read more