Stochastic Programming

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

Adaptive Scenario Partitioning for Stochastic Bilevel Linear Programs

Categories Bilevel Optimization, Constrained Nonlinear Optimization, Stochastic Programming Tags , , , ,

This paper develops an adaptive scenario partitioning approach for stochastic bilevel linear programs. The method extends the Adaptive Partitioning Method, originally designed for two-stage stochastic programs, to settings in which a leader makes a first-stage decision while anticipating scenario dependent optimal responses from a follower. The proposed approach solves a sequence of aggregated master problems … Read more

Distributionally Robust Optimization with General Uncertainty Structure

Categories Nonlinear Optimization, Robust Optimization, Stochastic Programming Tags , , , , , ,

We develop an exact solution framework for a broad class of Distributionally Robust Optimization (DRO) problems with general uncertainty structure. Within the class of moment- and confidence-set-based ambiguity sets, existing exact methods are largely limited to max-of-affine functions under ambiguity sets with strictly nested confidence sets. To enlarge this scope while preserving tractability, we introduce … Read more

Stage-wise hybrid nested Benders’ decomposition-stochastic dual dynamic programming for virtual power plants

Categories Dynamic Programming, Energy, Stochastic Programming Tags , , ,

Participants in energy markets make sequential decisions across multiple time horizons under uncertainty, leading to large-scale multistage stochastic optimization problems. Stochastic dual dynamic programming is widely used for its tractability, but its application to modern energy markets is challenged by nested dependencies induced by participation across multiple interrelated markets under increasing uncertainty from distributed energy … Read more

Scalable Finite Adaptability via Polyhedral Partition and Learning

Categories Applications - OR and Management Sciences, Robust Optimization, Stochastic Programming Tags , ,

We study finite adaptability for decision-making under uncertainty, where a small set of candidate solutions is prepared in advance and the best response is selected after uncertainty is realized. While existing methods have made significant progress on exact formulations, scalability remains a persistent challenge due to (i) the combinatorial nature of assigning decisions to uncertainty … Read more

Relief-based Anesthesiologist Scheduling with Stochastic Surgery Durations

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

We present a two-stage stochastic programming model for scheduling anesthesiologists to operating rooms under uncertainty in surgery durations. The proposed model takes a relief order to balance anesthesiologists’ workload as input and captures the trade-offs between anesthesiologist relief times, handoffs and under-staffing. To address the computational challenges of solving the proposed model, we derive supervalid … Read more

Extrapolation-based Direct Search for Nonsmooth Stochastic Zeroth-Order Optimization

Categories Nonlinear Optimization, Nonsmooth Optimization, Stochastic Programming Tags , ,

We propose and analyze a stochastic direct-search method for unconstrained zeroth-order minimization of locally Lipschitz, possibly nonsmooth, objectives. The method combines random polling directions with a stochastic extrapolating line search based on a sufficient-decrease test of order \(p\). Under conditional accuracy assumptions on the stochastic estimates, which can be verified for mean-zero finite-higher-moment oracle noise … Read more

Stochastic Bilevel Optimization for the Network Design of Multimodal Transit Systems with Heterogeneous Rider Preferences under Uncertain Travel Times and Demand

Categories Bilevel Optimization, Stochastic Programming, Transportation

Designing efficient and user-friendly multimodal transit networks is critical for modern urban mobility. We study a novel stochastic multimodal transit network design problem that integrates fixed-route services with on-demand shuttles, explicitly accounting for heterogeneous rider preferences, uncertain travel times, and passenger demand. The hierarchical decision-making process is modeled using a two-stage stochastic bilevel optimization problem, … Read more

Stochastic convergence of parallel asynchronous adaptive first-order methods

Categories Data Science Algorithms, Stochastic Programming, Unconstrained Optimization Tags , , , , ,

A new class of asynchronous adaptive first-order optimization methods is introduced, comprising asynchronous variants of several popular algorithms. Versions of these methods using momentum and/or inexact normalization are also considered. The convergence of methods in the class on non-convex functions is analyzed in a fully stochastic setting, and is shown to be (up to logarithmic … Read more