A framework to assess quality and uncertainty in disaster loss data

There is a growing interest in the systematic and consistent collection of disasterloss data for different applications. Therefore, the collected data must follow a set oftechnical requirements to guarantee its usefulness. One of those requirements is theavailability of a measure of the uncertainty in the collected data to express its quality for agiven purpose. Many of the existing disaster loss databases do not provide such uncertainty/qualitymeasures due to the lack of a simple and consistent approach to expressuncertainty. After reviewing existing literature on the subject, a framework to express theuncertainty in disaster loss data is proposed. This framework builds on an existinguncertainty classification that was updated and combined with an existing method for datacharacterization. The proposed approach is able to establish a global score that reflects theoverall uncertainty in a certain loss indicator and provides a measure of its quality

Design and prototype of a personal ascending device based on the principle of a capstan winch

Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014.Cataloged from PDF version of thesis.Includes bibliographical references (page 40).The consumer market currently offers no options for a low-cost, personal ascending device. The purpose of this project is to propose a powered ascender, actuated by common power tool components and operating on the principle of a capstan winch, as a candidate to fill that void. The first objective was to design and construct a working prototype. The second was to explore the feasibility of manufacturing a low cost consumer version of the product. Safety, functionality, and cost drove the design process. The ascender was designed and built around the motor and gearbox from a Dewalt 36v hammerdrill. Individual components were machined in undergraduate machine shops on the MIT campus and in the MIT Hobby Shop. Testing of the ascender was carried out using standard gym equipment and weights. The completed unit can lift 100 kg at 0.4 meters per second with an overall efficiency of 8.5%. This result was 57% lower than the predicted speed of 0.7 meters per second with an expected 14.7% efficiency. Analysis revealed a design flaw which can account for most of the discrepancy in the predicted and observed performance and which can easily be remedied. Powered ascenders within the same speed and load range are sold for several thousand dollars, demonstrating the feasibility of a low cost powered ascender as a viable product.by Daniel P. Gillund.S.B