Information for

2018 technical reports


Research Report on Infra Sound 


Richard Mann


We have successfully produced infrasound, as a mirror of that produced by Industrial Wind Turbines, in a chamber capable of accommodating a human test subject. This will permit others, with appropriate medical training and ethical oversight, to research the effects of infrasound on humans.

Date February 25, 2018; public release: March 2, 2018
Report CS-2018-01 (PDF)

Optimal Matching of Stochastic Solar Generators to Stochastic Loads


Sun Sun, Srinivasan Keshav, Catherine Rosenberg, Matthew Peloso


To meet the demand for locally-produced and sustainable power, community microgrids distribute power generated by roof-mounted solar PV systems to ‘green’ consumers. In this context, we consider the problem of matching one or more inherently intermittent solar energy producers with each green consumer so that, with a high probability, a certain component of their load is met from solar generation. We formulate this optimal matching as a stochastic optimization problem which incorporates the uncertainty of both solar and loads. To solve the problem, we propose four algorithms which make different assumptions on the distributions of solar generation and loads. We compare the performance of these algorithms using real data, and find that, for our dataset, an approach that assumes Gaussian mixture models for solar and loads best fits our design requirements. We also investigate admission control algorithms to admit customers based on our matching algorithms so that the solar allocation is feasible. 

Date April 2018
Report CS-2018-02 (PDF)

An Experimental Investigation on Understanding the Difficulties and Challenges of Software Modellers When Using Modelling Tools


Parsa Pourali, Joanne M. Atlee


Software modelling is a challenging, error-prone and tedious task. Existing Model-Driven Engineering (MDE) tools provide modellers with little aid, partly because tool providers have not investigated users’ difficulties through empirical investigations such as field studies. This report presents the results of a two-phase user study to identify the most prominent difficulties that users might face when using UML modelling tools. In the first phase, we identified the preliminary modelling challenges by analysing 30 models that were previously developed by students as a course assignment. The result of the first phase helped us to design the second phase of our user study where we empirically investigated different aspects of using modelling tools: the tools’ effectiveness, users’ efficiency, users’ satisfaction, the gap between users’ expectation and experience, and users’ cognitive difficulties. Our results suggest that users’ greatest difficulties are in (1) remembering contextual information and (2) identifying and fixing errors and inconsistencies.

Date May 2018
Report CS-2018-03 (PDF)