This paper addresses two second-best toll pricing problems, one with fixed and the other with elastic travel demands, as mathematical programs with equilibrium constraints. Several equivalent nonlinear programming formulations for the two problems are discussed. One formulation leads to properties that are of interest to transportation economists. Another produces an algorithm that is capable o...

This paper introduces six ways for handling a chain of lexicographic ordering constraint between the origins of identical orthotopes (e.g., rectangles, boxes, hyper-rectangles) subject to the fact that they should not pairwise overlap. While the first two ways deal with the integration of a chain of lexicographic ordering constraint within a generic geometric constraint kernel, the four latter ...

Symmetry is an important feature of many constraint programs. We show that any problem symmetry acting on a set of symmetry breaking constraints can be used to break symmetry. Different symmetries pick out different solutions in each symmetry class. This simple but powerful idea can be used in a number of different ways. We describe one application within model restarts, a search technique desi...

Microblog retrieval enables users to access relevant information from the huge number of tweets posted on social media. Since tweets are different from traditional documents, existing IR models might not be the optimal choice for this problem. Tie-breaking has been recently proposed as a new way of combining multiple retrieval signals. In this paper, we focus on studying the potential of this a...

The jaw plays a significant role in speech production. This work introduces a muscle activated dynamic jaw model that will be connected in the future to the 3D tongue model already developed by our group. The bone structure of the jaw, extracted from CT Images, is represented as a biomechanical model using quadrilateral shell elements. Opener and closer muscles are represented as line-segmented...

We consider a problem of managing a system of spatially distributed markets under capacity and balance constraints and show that solutions of a variational inequality enjoy auction principle properties implicitly. This enables us to develop efficient tools both for derivation of existence and uniqueness results and for creation of solution methods.

We analyze the effects of restricted participation in a two-period general equilibrium model with uncertainty in the second period and real assets. Similar to certain arrangements in the markets for bank loans, household borrowing is restricted by a household-specific lower bound on wealth in all states of uncertainty in the final period. After establishing that, generically in the set of the e...

This paper develops a model to examine the impacts of uncertainty about crop production and irreversibility of program participation on determining land rental payments and least-cost land retirement targeting in the Conservation Reserve Enhancement Program. Results show that under risk aversion only, the marginal cost of abatement and the average land rental payment are less than those under r...

This paper describes and demonstrates the derivation of a system of demands for activity participation by applying microeconomic theory in a time-price setting. Both time and money constraints are incorporated explicitly and the integer nature of demand observations is accommodated via a multivariate negative binomial stochastic specification. A model based on this theory is calibrated, providi...

With the widespread use of mobile phones in the developing world, interactive voice response (IVR) systems are increasingly accessible to people with low literacy and/or limited financial resources. Interest in using IVR systems as a means to increase citizen participation in society has increased. Yet, research exploring the potential of IVRs—with particular affordances, constraints, and norms...