A guided tour through the zoo of paired optimization problems

Many mathematical models base on the coupling of two or more optimization problems. This paper surveys possibilities to couple two optimization problems and discusses how solutions of the different models are interrelated with each other. The considered pairs stem from the fields of standard and generalized Nash equilibrium problems, optimistic and pessimistic bilevel problems, saddle … Read more

Data-Driven Optimization for Meal Delivery: A Reinforcement Learning Approach for Order-Courier Assignment and Routing at Meituan

The rapid growth of online meal delivery has introduced complex logistical challenges, where platforms must dynamically assign orders to couriers while accounting for demand uncertainty, courier autonomy, and service efficiency. Traditional dispatching methods, often focused on short-term cost minimization, fail to capture the long-term implications of assignment decisions on system-wide performance. This paper presents a … Read more

blockSQP 2: exploiting structure to improve performance

Abstract One approach to solving optimal control problems is Bock’s direct multiple shoot- ing method. This method yields lifted nonlinear optimization problems (NLPs) with a spe- cific block structure. Exploiting this structure via tailored optimization algorithms can be computationally beneficial. We propose such methods, primarily within the framework of fil- ter line search sequential quadratic … Read more

The Exclusion-Inclusion Gap for Evaluating Finite Pareto Approximations in Multiobjective Stochastic Optimization

We introduce the exclusion–inclusion gap for evaluating finite Pareto approximations constructed from stochastic objective estimates. The gap measures the maximum of two objective-space errors associated with excluding Pareto points from the returned set’s true upper image and including dominated points in the returned set’s true lower image. The terms in its approximation–estimation error decomposition admit … Read more

A Multivariate Loss Ratio Approach for Systemic Risk Measurement and Allocation

The primary challenges in systemic risk measurement involve determining an overall reserve level of risk capital and allocating it to different components based on their systemic relevance. In this paper, we introduce a multivariate loss ratio measure (MLRM), which is the minimum amount of capital to be injected into a financial system such that the … Read more

Properties of Enclosures in Multiobjective Optimization

A widely used approximation concept in multiobjective optimization is the concept of enclosures. These are unions of boxes defined by lower and upper bound sets that are used to cover optimal sets of multiobjective optimization problems in the image space. The width of an enclosure is taken as a quality measure. In this paper, we … Read more

Consistent and unbiased estimation of the hypervolume of an unknown true Pareto front

Hypervolume is most likely the most often used set quality indicator in (evolutionary) multi-objective optimization. It may be used to compare the quality of solution sets whose images in the objective space are approximations of the true Pareto front. Although in this way we may compare two or more approximations, our knowledge is limited without … Read more

Isotonic Optimization with Fixed Costs

This paper introduces a generalized isotonic optimization framework over an arborescence graph, where each node incurs state-dependent convex costs and a fixed cost upon strict increases. We begin with the special case in which the arborescence is a path and develop a dynamic programming (DP) algorithm with an initial complexity of $O(n^3)$, which we improve … Read more

Assessing Green Hydrogen Production via Offshore Wind in the Dutch North Sea: Complementing Techno-Economic Simulation With Machine Learning and Optimization

As countries seek to decarbonize their energy systems, green hydrogen has emerged as a promising energy carrier. This paper studies the production of green hydrogen from offshore wind in the Dutch North Sea, with particular emphasis on understanding how system design decisions and uncertain parameters affect key performance indicators. The analysis builds on a detailed … Read more

On Subproblem Tradeoffs in Decomposition and Coordination of Multiobjective Optimization Problems

We propose a two-stage methodology to support decision-making for large/complex multiobjective optimization problems (MOPs) with a decomposable structure, regardless of whether the MOP, due to its size, is solvable in its entirety. During the first stage, the MOP is decomposed into a collection of multiobjective subproblems each of which have fewer objectives than the original … Read more