Feedback and time are essential for the optimal control of computing systems

The performance, reliability, cost, size and energy usage of computing systems can be improved by one or more orders of magnitude by the systematic use of modern control and optimization methods. Computing systems rely on the use of feedback algorithms to schedule tasks, data and resources, but the models that are used to design these algorithms are validated using open-loop metrics. By using closed-loop metrics instead, such as the gap metric developed in the control community, it should be possible to develop improved scheduling algorithms and computing systems that have not been over-engineered. Furthermore, scheduling problems are most naturally formulated as constraint satisfaction or mathematical optimization problems, but these are seldom implemented using state of the art numerical methods, nor do they explicitly take into account the fact that the scheduling problem itself takes time to solve. This paper makes the case that recent results in real-time model predictive control, where optimization problems are solved in order to control a process that evolves in time, are likely to form the basis of scheduling algorithms of the future. We therefore outline some of the research problems and opportunities that could arise by explicitly considering feedback and time when designing optimal scheduling algorithms for computing systems

US Real Estate Investment Performance: 1983-2012

This study provides an overview of real estate investment performance over a 1983-2012 time period. The results show that although equity REITs outperformed all other assets on average annual return, on a risk-adjusted basis both private retail and apartment real estate outperformed all other assets. The study also found a recent trend in increased correlation between common stocks and REITs

Robustly stable feedback min-max model predictive control

Published versio

“Clinic and the wider law curriculum”

The problem this paper addresses is that although there is general consensus as to the value of clinic and recognition that it has enhanced creativity and vitality in legal education, there is still a tendency to see it as something apart from the regular law curriculum. We want to explore the viability of making the key benefits of clinical education pervade the whole of the student’s time learning the law. We draw some encouragement from official reports from the US and the UK which, although not concerned primarily with the place of clinical legal education, do provide general support for an approach which combines theory and practice