Estimation of Marginal Cost to Serve Individual Customers

This paper proposes a scenario sampling-based framework to estimate the expected incremental routing cost required so as to incorporate a target customer into an inherently stochastic supply chain network. Inspired from a real-life setting arising in the distribution of industrial gases, we demonstrate our framework and elucidate the quality of the marginal cost estimates it … Read more

Substitution-based Equipment Balancing in Service Networks with Multiple Equipment Types

We investigate substitution-based equipment balancing for a package express carrier operating multiple equipment types in its service network. The weekly schedule of movements used to transport packages through the service network leads to changes in equipment inventory at the facilities in the network. We seek to reduce this change, i.e., the equipment imbalance associated with … Read more

Robust location-transportation problems with integer-valued demand

A location-transportation problem concerns designing a company’s distribution network consisting of one central warehouse with ample stock and multiple local warehouses for a long but finite time horizon. The network is designed to satisfy the demands of geographically dispersed customers for multiple products within given delivery time targets. The company needs to first decide on … Read more

On pricing-based equilibrium for network expansion planning. A multi-period bilevel approach under uncertainty

This study focuses on the development of a mixed binary primal-dual bilinear model for multi-period bilevel network expansion planning under uncertainty, where pricing-based equilibrated strategic and operational decisions are to be made. The periodwise dependent parameters’ uncertainty is represented by a _nite set of scenarios. Pricing-based equilibrium is required in the models to be optimized … Read more

Dynamic programming for the time-dependent traveling salesman problem with time windows

The recent growth of direct-to-consumer deliveries has stressed the importance of last-mile logistics, becoming one of the critical factors in city planning. One of the key factors lies in the last-mile deliveries, reaching in some cases nearly 50% of the overall parcel delivery cost. Different variants of the the well-known Traveling Salesman Problem (TSP) arise … Read more

Risk-Neutral and Risk-Averse Transmission Switching for Load Shed Recovery

Maintaining an uninterrupted supply of electricity is a fundamental goal of power systems operators. However, due to critical outage events, customer demand or load is at times disconnected or shed temporarily. While deterministic optimization models have been devised to help operators expedite load shed recovery by harnessing the flexibility of the grid’s topology (i.e., transmission … Read more

Joint Pricing and Production: A Fusion of Machine Learning and Robust Optimization

We integrate machine learning with distributionally robust optimization to address a two-period problem for the joint pricing and production of multiple items. First, we generalize the additive demand model to capture both cross-product and cross-period effects as well as the demand dependence across periods. Next, we apply K-means clustering to the demand residual mapping based … Read more

An integrated planning model in centralized power systems

In the context of centralized electricity markets, we propose an integrated planning model for power pricing and network expansion, which endogenizes the scaling costs from power losses. While the substitutability pattern between pricing and expansion has been overlooked in the power flow optimization literature, this becomes particularly relevant in centralized electricity markets (where the headquarters … Read more

A subspace-accelerated split Bregman method for sparse data recovery with joint l1-type regularizers

We propose a subspace-accelerated Bregman method for the linearly constrained minimization of functions of the form f(u)+tau_1 ||u||_1 + tau_2 ||D*u||_1, where f is a smooth convex function and D represents a linear operator, e.g. a finite difference operator, as in anisotropic Total Variation and fused-lasso regularizations. Problems of this type arise in a wide … Read more

Distributionally Robust Facility Location Problem under Decision-dependent Stochastic Demand

Facility location decisions significantly impact customer behavior and consequently the resulting demand in a wide range of businesses. Furthermore, sequentially realized uncertain demand enforces strategically determining locations under partial information. To address these issues, we study a facility location problem where the distribution of customer demand is dependent on location decisions. We represent moment information … Read more