MSc BBQ

The Scottish weather proved favourable for the MSc barbecue yesterday. An excellent turn out with over 50 MSc students sampling burgers, sausages and the local delicacy Irn Bru. Photographic evidence provided.

The Dependability of Complex Socio-technical Infrastructure & Smart Grids and Smart Meters: Game Changer, or Serious Danger? by Prof. Ross Anderson

DLS Programme

Lecture 1: The Dependability of Complex Socio-technical Infrastructure

Abstract: We have all become dependent on large complex systems such as Facebook, the bank payment system and even the Internet itself.

Keeping these systems dependable in the face of accidents, errors and malice is one of the most important, and interesting, challenges facing engineers today. It brings not only technical problems of the highest order, but also some intricate economics; how do we persuade firms to invest in spare capacity that will mostly help their competitors offer better service? I’ll discuss such problems in two contexts: frauds against payment networks, and the resilience of the Internet. The talk will draw on a recent major study we did for ENISA of the resilience of the Internet interconnect.

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Event details

  • When: 5th December 2011 13:30 - 17:00
  • Where: Purdie Theatre B
  • Series: Distinguished Lectures Series

Learning hard chart constraints for efficient context-free parsing by Brian Roark – Oregon Health & Science University

Abstract: In this talk, I’ll present some recent work in learning hard constraints for cells within a context-free parsing chart, to reduce parsing time. Each cell in the chart represents one of the O(n^2) substrings of the input string, and characteristics of each substring can be used to decide how much work to do in the associated chart cell. I’ll discuss finite-state models for tagging chart constraints on words, including methods for bounding the worst-case complexity of the parsing pipeline to quadratic or sub-quadratic in the length of the string. Empirical results will be presented for English and Chinese, achieved by constraining various high accuracy parsers.

Finally, I will present a generalization of these finite-state approaches that performs a quadratic number of classifications (one for each substring) to produce further (finer) constraints on the amount of processing within each cell. This latter approach has the nice property of being trained on maximum likelihood parses, rather than reference parses, making for a straightforward method for tuning parsing efficiency to new tasks and domains.

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Event details

  • When: 27th September 2011 13:00 - 14:00
  • Where: Cole 1.33
  • Series: CS Colloquia Series
  • Format: Colloquium

Is provenance logical? (James Cheney, University of Edinburgh)

Research on provenance in databases (or other settings) sometimes has an arbitrary flavor. Once we abandon the classical semantics of queries there is a large design space for alternative semantics that could provide some useful provenance information, but there is little guidance for how to explore this space or justify or compare different proposals. Topics from mathematical or philosophical logic could be used as a way of inspiring, justifying or comparing different approaches to provenance in databases. This talk will give a short tutorial on provenance in databases and present several topics in logic that may bear upon provenance techniques. These areas include nonclassical logics (e.g. relevance logic), algebraic logic (cylindric algebras), substructural logic (e.g. linear logic) and logics of knowledge, belief or causality.

Event details

  • When: 21st September 2011 13:00 - 14:00
  • Where: Cole 1.33a
  • Format: Seminar

Staff BBQ

Despite the weather conditions, the end of summer BBQ went ahead, on Friday.

It provided the perfect opportunity to welcome new members of staff and newly arrived PhD students. Congratulations also to Greg on submitting his thesis, and farewell to Angus who will be starting work in New York soon.

Exploring semantics in situation identification using context lattices by Dr.Juan Ye

Pervasive systems must offer an open, extensible, and evolving portfolio of services which integrate sensor data from a diverse range of sources. The core challenge is to provide appropriate and consistent adaptive behaviours for these services in the face of huge volumes of sensor data exhibiting varying degrees of precision, accuracy and dynamism. Situation identification is an enabling technology that resolves noisy sensor data and abstracts it into higher-level concepts that are interesting to applications. 

In this talk, I will provide a comprehensive analysis of the nature and characteristics of situations, discuss the complexities of situation identification, and introduce a novel situation identification technique called “context lattice”. The context lattice is built on a sound mathematical model, aiming to identify situations by systematically exploring the semantics of sensor data, domain knowledge, and situations in a pervasive computing system. I will present and discuss the evaluation results when applying this technique to recognising human activities in smart home environments. This talk will be concluded with challenging questions in the area of situation identification.
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Event details

  • When: 3rd October 2011 14:00 - 15:00
  • Where: Cole 1.33
  • Series: CS Colloquia Series
  • Format: Colloquium