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.

Entwicklung eines anpassungsfähigen Internet-Designs für die Firma „blueways“, unter Berücksichtigung des User- Verhaltens und Aspekten der Usability

[s.c.]

Ramp Adaptive Metering Bottleneck Optimization (RAMBO) user's manual.

Texas Department of Transportation, Austin

WRAP, a model for regional solid waste management planning : a user's guide.

Mode of access: Internet.

TCM analyst 1.0 and user's guide.

Texas Department of Transportation, Austin

Analytical modeling of driver response in crash avoidance maneuvering. Volume IV: user's guide for linear analysis, nonlinear simulation, part task simulation. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Sensitivity analysis of vehicle design attributes that affect vehicle response in critical accident situations - part 1: user's manual. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

PROMETHEUS 2 - a user oriented program for human crash dynamics. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Development of a low cost anti-lock brake system for small motorcycles. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

GRASS: terminal user's guide,

Includes bibliographical references.

Beach Profile Analysis System (BPAS) /

"June 1982."

CHRI user's manual : criminal history record information /

This guide provides examples of juvenile and adult arrest fingerprint cards with instructions and additional record forms.

Draft PC-TARE user's guide.

Cover title.

Ice-atmosphere interactions and sea ice predictability at multiple resolutions in the Community Earth System Model

Thesis (Master's)--University of Washington, 2016-06

Ex ante evaluations of alternate data structures for end user queries: Theory and experimental test

The data structure of an information system can significantly impact the ability of end users to efficiently and effectively retrieve the information they need. This research develops a methodology for evaluating, ex ante, the relative desirability of alternative data structures for end user queries. This research theorizes that the data structure that yields the lowest weighted average complexity for a representative sample of information requests is the most desirable data structure for end user queries. The theory was tested in an experiment that compared queries from two different relational database schemas. As theorized, end users querying the data structure associated with the less complex queries performed better Complexity was measured using three different Halstead metrics. Each of the three metrics provided excellent predictions of end user performance. This research supplies strong evidence that organizations can use complexity metrics to evaluate, ex ante, the desirability of alternate data structures. Organizations can use these evaluations to enhance the efficient and effective retrieval of information by creating data structures that minimize end user query complexity.