THE DESIGN OF A POWER SYSTEM FOR A WIRELESS SENSOR NETWORK FOR LONG-TERM OPERATION

Wireless sensor networks (WSNs) have shown wide applicability to many fields including monitoring of environmental, civil, and industrial settings. WSNs however are resource constrained by many competing factors that span their hardware, software, and networking. One of the central resource constrains is the charge consumption of WSN nodes. With finite energy supplies, low charge consumption is needed to ensure long lifetimes and success of WSNs. This thesis details the design of a power system to support long-term operation of WSNs. The power system’s development occurs in parallel with a custom WSN from the Queen’s MEMS Lab (QML-WSN), with the goal of supporting a 1+ year lifetime without sacrificing functionality. The final power system design utilizes a TPS62740 DC-DC converter with AA alkaline batteries to efficiently supply the nodes while providing battery monitoring functionality and an expansion slot for future development. Testing tools for measuring current draw and charge consumption were created along with analysis and processing software. Through their use charge consumption of the power system was drastically lowered and issues in QML-WSN were identified and resolved including the proper shutdown of accelerometers, and incorrect microcontroller unit (MCU) power pin connection. Controlled current profiling revealed unexpected behaviour of nodes and detailed current-voltage relationships. These relationships were utilized with a lifetime projection model to estimate a lifetime between 521-551 days, depending on the mode of operation. The power system and QML-WSN were tested over a long term trial lasting 272+ days in an industrial testbed to monitor an air compressor pump. Environmental factors were found to influence the behaviour of nodes leading to increased charge consumption, while a node in an office setting was still operating at the conclusion of the trail. This agrees with the lifetime projection and gives a strong indication that a 1+ year lifetime is achievable. Additionally, a light-weight charge consumption model was developed which allows charge consumption information of nodes in a distributed WSN to be monitored. This model was tested in a laboratory setting demonstrating +95% accuracy for high packet reception rate WSNs across varying data rates, battery supply capacities, and runtimes up to full battery depletion.

The political economy of industrial policy in Peru and Ecuador: 1980-2010

This dissertation focuses on industrial policy in two developing countries: Peru and Ecuador. Informed by comparative historical analysis, it explains how the Import-Substitution Industrialization policies promoted during the 1970s by military administration unravelled in the following 30 years under the guidance of Washington Consensus policies. Positioning political economy in time, the research objectives were two-fold: understanding long-term policy reform patterns, including the variables that conditioned cyclical versus path-dependent dynamics of change and; secondly, investigating the direction and leverage of state institutions supporting the manufacturing sector at the dawn, peak and consolidation of neoliberal discourse in both countries. Three interconnected causal mechanisms explain the divergence of trajectories: institutional legacies, coordination among actors and economic distribution of power. Peru’s long tradition of a minimal state contrasts with the embedded character of Ecuador long tradition of legal protectionism dating back to the Liberal Revolution. Peru’s close policy coordination among stakeholders –state technocrats and business elites- differs from Ecuador’s “winners-take-all” approach for policy-making. Peru’s economic dynamism concentrated in Lima sharply departs from Ecuador’s competitive regional economic leaderships. This dissertation paid particular attention to methodology to understand the intersection between structure and agency in policy change. Tracing primary and secondary sources, as well as key pieces of legislation, became critical to understand key turning points and long-term patterns of change. Open-ended interviews (N=58) with two stakeholder groups (business elites and bureaucrats) compounded the effort to knit motives, discourses, and interests behind this long transition. In order to understand this amount of data, this research build an index of policy intervention as a methodological contribution to assess long patterns of policy change. These findings contribute to the current literature on State-market relations and varieties of capitalism, institutional change, and policy reform.