Communication system for a tooth-mounted RF sensor used for continuous monitoring of nutrient intake

In this Thesis, the communication system of a wearable device that monitors the user’s diet is studied. Based in a novel RF metamaterial-based mouth sensor, different decisions have to be made concerning the system’s technologies, such as the power source options for the device, the wireless technology used for communications and the method to obtain data from the sensor. These issues, along with other safety rules and regulations, are reviewed, as the first stage of development of the Food-Intake Monitoring projectOutgoin

A Theory of Political Influence and Economic Organization

I propose a cooperative game theory model of economic reform in a political environment with interest groups. Agents in a better economic position have strategic advantage in formulating economic policy. Agents bargain over policies because they are associated with different income distributions. In this context I examine the robustness of the `Coase Theorem' prediction of efficient bargaining. I use the Aspiration Core and the Aspiration Bargaining Set as solutions to the cooperative game. Even under zero transaction costs, if endogenous coalition formation is allowed, bargaining between interest groups need not result in efficient economic change because the core may be empty. Indeed, I show that there are inefficient equilibrium outcomes if and only if the core is empty.Political Economy, Interest Groups, Institutional Change, Coalition Formation, Cooperative Games, Aspiration Solution Concepts

Interest Groups and Trade Reform in Mexico

Mexico experienced widespread economic reform in the last two decades. From being a protectionist economy with a policy of import substitution, it has turned into an export-oriented open economy. Why was protectionism a stable policy, and how was it overturned by a reform that went against entrenched interests? I apply a game theoretic model of political influence and economic reform to answer these questions using data to calculate the payoffs for the relevant interest groups. In the underlying cooperative game, the core is empty and a protectionist coalition of import-substituting firms and the government was "stable" until the eighties. Adjusting the model's parameters to changes in the government's financing options in the late eighties and early nineties leads to a different and unique outcome. In the predicted outcome a free trade policy is adopted through cooperation between all players.Trade Reform, Mexico, Coalition Formation, Aspirations, Cooperative Games, Interest Groups

Spanning trees of 3-uniform hypergraphs

Masbaum and Vaintrob's "Pfaffian matrix tree theorem" implies that counting spanning trees of a 3-uniform hypergraph (abbreviated to 3-graph) can be done in polynomial time for a class of "3-Pfaffian" 3-graphs, comparable to and related to the class of Pfaffian graphs. We prove a complexity result for recognizing a 3-Pfaffian 3-graph and describe two large classes of 3-Pfaffian 3-graphs -- one of these is given by a forbidden subgraph characterization analogous to Little's for bipartite Pfaffian graphs, and the other consists of a class of partial Steiner triple systems for which the property of being 3-Pfaffian can be reduced to the property of an associated graph being Pfaffian. We exhibit an infinite set of partial Steiner triple systems that are not 3-Pfaffian, none of which can be reduced to any other by deletion or contraction of triples. We also find some necessary or sufficient conditions for the existence of a spanning tree of a 3-graph (much more succinct than can be obtained by the currently fastest polynomial-time algorithm of Gabow and Stallmann for finding a spanning tree) and a superexponential lower bound on the number of spanning trees of a Steiner triple system.Comment: 34 pages, 9 figure

Consumer Cooperatives: An Alternative Institutional Model for Delivery of Urban Water Supply and Sanitation Services?

This paper describes the essential characteristics of consumer cooperatives engaged in the provision of basic services and discusses their applicability as a model for water supply and sanitation service provision in urban areas. A cooperative is an autonomous association of persons united voluntarily to meet their common economic, social, and cultural needs and aspirations through a jointly-owned and democratically-controlled enterprise. The paper focuses on system-wide urban water supply cooperatives and it is thus not concerned with urban or peri-urban cooperatives that depend on either boreholes or bulk purchases of water from a utility for distribution, nor does it refer to rural water supply cooperatives that are generally small. After a general overview of cooperatives and a discussion of the main characteristics of utility cooperatives, the paper reviews the case of SAGUAPAC, a successful urban WSS cooperative in Bolivia, from which it draws some conclusions in the form of a preliminary assessment of cooperatives as a model for delivery of urban water supply and sanitation (WSS) services

A solution to the tennis ball problem

We present a complete solution to the so-called tennis ball problem, which is equivalent to counting lattice paths in the plane that use North and East steps and lie between certain boundaries. The solution takes the form of explicit expressions for the corresponding generating functions. Our method is based on the properties of Tutte polynomials of matroids associated to lattice paths. We also show how the same method provides a solution to a wide generalization of the problem.Comment: 9 pages, Late