This paper addresses the optimal design and planning of cellulosic ethanol supply chains under economic, environmental, and social objectives. The economic objective is measured by the total annualized cost, the environmental objective is measured by the life cycle greenhouse gas emissions, and the social objective is measured by the number of accrued local jobs. A multiobjective mixed-integer ...

A new planning method for optimal control of multi-robot systems is discussed which accounts for the (continuous) physical locomotion dynamics of the robots and its tight coupling to the distribution and allocation of (discrete) subtasks to the robots to fulfill a joint mission. The point of departure is a nonlinear and nonconvex hybrid optimal control problem (HOCP) formulation which incorpora...

Partially observed Markov decision processes (POMDPs) serve as powerful tools to model stochastic systems with partial state information. Since the exact solution methods for POMDPs are limited to problems with very small sizes of state, action and observation spaces, approximate pointbased solution methods like Perseus have gained popularity. In this work, a mixed integer linear program (MILP)...

Power gating is a very effective technique to reduce the subthreshold leakage by using sleep transistors to turn off the functional blocks or cells when they are not used. When the sleep transistors are turned on, the power grid may experience a huge current surge which may violate the integrity of the power grid. This paper addresses this problem by formulating the wakeup scheduling of sleep t...

A large number of planning and scheduling problems can be formulated as multiperiod MILP models which often require substantial computational expense for their sohition. This paper presents and demonstrates the value of nonstandard formulations of such problems. Based on a variable disaggregation technique which exploits lot sizing substructures, we propose a strategy for the reformulation of c...

In this work we present an Outer-Approximation algorithm to obtain the global optimum of a nonconvex Mixed Integer Nonlinear Programming (MINLP) model for the scheduling of crude oil movement at the front-end of a petroleum refinery. The model relies on a continuous time representation making use of transfer events. The proposed technique focuses on effectively solving a Mixed Integer Linear Pr...

We discuss the problem of combining the conflicting objectives of equity and utilitarianism, for social policy making, in a single mathematical programming model. The definition of equity we use is the Rawlsian one of maximising the minimum utility over individuals or classes of individuals. However, when the disparity of utility becomes too great, the objective becomes progressively utilitaria...

First-order programming (FOP) is a new representation language that combines the strengths of mixed-integer linear programming (MILP) and first-order logic (FOL). In this paper we describe a novel feasibility proving system for FOP formulas that combines MILP solving with instance-based methods from theorem proving. This prover allows us to perform lifted inference by repeatedly refining a prop...