Hierarchical Benders Decomposition for Open-Pit Mine Block Sequencing
The open-pit mine block sequencing problem (OPBS) models a deposit of ore and surrounding material near the Earth’s surface as a three-dimensional grid of blocks. A solution in discretized time identifies a profit-maximizing extraction (mining) schedule ...
Combining Spot and Futures Markets: A Hybrid Market Approach to Dynamic Spectrum Access
Dynamic spectrum access is a new paradigm of secondary spectrum utilization and sharing. It allows unlicensed secondary users (SUs) to exploit the opportunistically underutilized licensed spectrum. Market mechanism is a widely used promising means to ...
Efficient Advert Assignment
We develop a framework for the analysis of large-scale ad auctions where adverts are assigned over a continuum of search types. For this pay-per-click market, we provide an efficient mechanism that maximizes social welfare. In particular, we show that the ...
New Formulations for the Conflict Resolution Problem in the Scheduling of Television Commercials
We consider the conflict-resolution problem arising in the allocation of commercial advertisements to television program breaks. Because of the competition-avoidance requirements issued by advertisers, broadcasters aim to allocate any pairs of commercials ...
Tax-Aware Dynamic Asset Allocation
We consider dynamic asset allocation problems where the agent is required to pay capital gains taxes on her investment gains. These are very challenging problems because the tax owed whenever a security is sold depends on the cost basis, and this results ...
Modeling Load and Overwork Effects in Queueing Systems with Adaptive Service Rates
Servers in many real queueing systems do not work at a constant speed. They adapt to the system state by speeding up when the system is highly loaded or slowing down when load has been high for an extended time period. Their speed can also be constrained ...
A Markov Chain Approximation to Choice Modeling
Assortment planning is an important problem that arises in many industries such as retailing and airlines. One of the key challenges in an assortment planning problem is to identify the “right” model for the substitution behavior of customers from the ...
Exact Analysis of Divergent Inventory Systems with Time-Based Shipment Consolidation and Compound Poisson Demand
Sustainable and efficient management of a distribution system requires coordination between transportation planning and inventory control decisions. In this context, we consider a one warehouse multi-retailer inventory system with a time-based shipment ...
A Cycle-Based Formulation and Valid Inequalities for DC Power Transmission Problems with Switching
It is well known that optimizing network topology by switching on and off transmission lines improves the efficiency of power delivery in electrical networks. In fact, the USA Energy Policy Act of 2005 (Section 1223) states that the United States should “...
Solving Chance-Constrained Optimization Problems with Stochastic Quadratic Inequalities
We propose a new and systematic reformulation and algorithmic approach to solve a complex class of stochastic programming problems involving a joint chance constraint with random technology matrix and stochastic quadratic inequalities. The method is ...
Statistical Optimization in High Dimensions
We consider optimization problems whose parameters are known only approximately, based on noisy samples. In large-scale applications, the number of samples one can collect is typically of the same order of (or even less than) the dimensionality of the ...
Multistage Robust Mixed-Integer Optimization with Adaptive Partitions
We present a new partition-and-bound method for multistage adaptive mixed-integer optimization (AMIO) problems that extends previous work on finite adaptability. The approach analyzes the optimal solution to a static (nonadaptive) version of an AMIO ...
Robust Control of Partially Observable Failing Systems
This paper is concerned with optimal maintenance decision making in the presence of model misspecification. Specifically, we are interested in the situation where the decision maker fears that a nominal Bayesian model may be miss-specified or unrealistic, ...
Unemployment Risks and Optimal Retirement in an Incomplete Market
We develop a new approach for solving the optimal retirement problem for an individual with an unhedgeable income risk. The income risk stems from a forced unemployment event, which occurs as an exponentially distributed random shock. The optimal ...
Routing and Staffing When Servers Are Strategic
Traditionally, research focusing on the design of routing and staffing policies for service systems has modeled servers as having fixed (possibly heterogeneous) service rates. However, service systems are generally staffed by people. Furthermore, people ...