SDDP has polynomial iteration complexity in the horizon

Stochastic dual dynamic programming (SDDP) and its variants are run in practice with forward passes that sample the noise at random. Recent iteration-complexity results favour another choice: when the trial points are selected deterministically, for instance along the scenario with the largest gap, the number of iterations is polynomial in the horizon $T$, whereas every … Read more

A tight 1/3–approximation algorithm and fully polynomial-time approximation schemes for the Colored Knapsack Problem

The \(\textit{Colored Knapsack Problem}\) (ColKP) generalizes the classical Knapsack Problem by partitioning the items into color classes and requiring the selected items to admit an ordering in which consecutive items have different colors. The problem is weakly \(\mathcal{NP}\)-hard and admits two pseudo-polynomial dynamic programming (DP) algorithms proposed in the literature. These two DP algorithms have … Read more

Differentiating Through Moving Recourse: Feasible Policy Optimization and Finite-Sample Certification for Multistage Stochastic Programs

Multistage stochastic programs model decisions under uncertainty where earlier decisions change later feasible sets. We propose a feasible pathwise gradient method (FeasPG) that can update the policy as new sample paths arrive. The policy proposes a decision and projects it onto the current feasible set, so every decision is feasible. We derive the full trajectory … Read more

Nonlinear optimization over trees with binary coupling decisions

Mixed integer nonlinear programs with binary coupling decisions naturally model selective coordination tasks where a fixed penalty is incurred whenever adjacent continuous variables differ. A prominent example is the classical Potts model, which is widely used in statistical inference. However, exact solvability remains theoretically challenging since the problem is NP hard on general graphs, and … Read more

Convexification of mixed-integer quadratic optimization via decision diagrams

We study mixed-integer quadratic optimization (MIQO) problems with indicator variables. We propose a unified framework, based on decision diagrams, that serves both to solve the associated optimization problems and to construct ideal conic quadratic extended formulations of the closure of the convex hull of the underlying mixed-integer set. The construction applies to arbitrary quadratics and … Read more

DD-suite: A cross-platform package to build Decision Diagrams for optimization purposes

Decision diagrams (DDs) have become a powerful tool for discrete optimization, supporting a wide range of algorithms that span cut-generation procedures, decomposition methods, and specialized branch-and-bound searches. Despite this growth, their adoption remains limited, partly because most existing DD code is tailored to a specific algorithm or application and is therefore hard to reuse. We … Read more

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

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

Approximate solution of infinite-horizon risk-sensitive Markov decision processes

Infinite-horizon risk-sensitive Markov decision processes (MDPs) under the discounted cost criterion are challenging to solve because the optimal policy may be nonstationary. Existing methods  typically reformulate the problem as a continuous-state risk-neutral MDP and rely on state discretization or value-function approximation, often without explicit stopping conditions or error bounds. In this paper, we present approximate … Read more

Stochastic Queens Elimination

This research introduces the Stochastic Sequential Queens Elimination Problem, where on the \(n\)-queens board, each activated queen simultaneously attempts to eliminate all queens in her unblocked neighborhood, each independently succeeding with probability \(p\). The objective is to minimize the expected cumulative conflict count over the trajectory. This research proposes a Markov decision process for this … Read more

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

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