Systems Seminar: Coupled Adaptive Complex Network, by Saray Shai, University of St Andrews

Abstract:

This talk presents the introduction and our early investigation on coupled adaptive complex networks. Generally an adaptive network is the network whose topology adapts and evolves with the dynamics of the network. At present, adaptive networks are ubiquitous across many disciplines, including technical distribution networks such as road networks and the internet; natural and biological networks; and social science networks. These networks are often interact with or depend upon other networks, resulting in coupled adaptive networks.

In this talk, we present our recent study of susceptible-infected-susceptible (SIS) epidemic dynamics on coupled adaptive networks, where susceptible nodes are able to avoid contact with infection by rewiring their intra-network connections. However, infected nodes can pass the disease through inter-network connections, which do not change with time: the dependencies between the coupled networks remain constant.

An analytical formalism is developed and validated using extensive numerical simulation. The experiment results show that the stability is increased with the increase in the number of inter-network links, in the sense that the range of parameters over which both endemic and healthy states coexist (both solution branches are stable) becomes smaller. Also we find a new stable solution branch that does not appear in the case of single adaptive network but only in the case of weakly coupled networks, in which the disease is endemic in one network but neither becomes endemic nor dies out in the other. Instead, it persists only at the nodes that are coupled to nodes in the other network through inter-network links.

Event details

  • When: 29th January 2013 13:00 - 14:00
  • Where: Cole 1.33b
  • Format: Seminar

Towards reliable and responsible social network research by Tristan Henderson – University of St Andrews

This seminar is suitable for CS3053-RPIC

Abstract
Social network sites (SNSs) such as Facebook and Twitter are used by hundreds of millions of people daily. As such they represent an attractive source of data for research. Many researchers have crawled these SNSs to collect data for projects involving psychology, sociology, health, and of course computer science. But there are many risks to naively crawling an SNS, ranging from data protection and privacy concerns to the reliability of the collected data.

Continue reading

Event details

  • When: 11th February 2013 15:00 - 16:00
  • Where: Phys Theatre C
  • Series: CS Colloquia Series
  • Format: Colloquium, Seminar

New EPSRC Grant – Working Together: Constraint Programming and Cloud Computing

We are looking for a Research Fellow to work on this grant! See the job advert (deadline 28 Feb): Research Fellow in Computer Science

Ian Miguel, Adam Barker, and Martin Dominik (of the School of Physics & Astronomy) have been awarded £630K, 3-year grant from the EPSRC for “Working Together: Constraint Programming and Cloud Computing”. Cloud Computing and Constraint Programming are two active, important research streams, both of which will realise significant and sustained benefits from working in concert. Constraint programming is a proven technology for solving complex combinatorial problems. However, the inherent difficulty of these problems means that performance can be variable, often requiring tuning by an expert to obtain best results. One approach to obtaining more robust performance is to employ a portfolio of solvers with complementary strengths. The scalable resource offered by the cloud is perfectly suited to the deployment of such portfolios and presents the opportunity to employ large solver portfolios to tackle challenge problems of exceptional difficulty. Conversely, a major concern in cloud computing is how to deploy an application on the available infrastructure so as to maximise performance and minimise operating costs. Added complexity arises when dealing with Big Data scenarios where it is important to run computation as closely (in terms of network distance) as possible to the data, in order to minimise network latency and maximise the performance of an application. This is a difficult combinatorial problem with a large set of variables including: public cloud provider, cloud configuration, geographical region, pricing etc. to which constraint programming is ideally suited.

Our two primary research streams in ICT will interact and work together with a third in astronomy to deliver a solution to a major challenge application: scheduling telescope observations to measure the abundance of planets throughout the Milky Way. If successful, the benefit to astronomy is clear, but our two primary streams will also benefit greatly from a major evaluation of their ability to work together to solve a large, complex problem.

CANCELLED Unikernels: Functional Library Operating Systems for the Cloud by Anil Madhavapeddy, University of Cambridge

(followed by tea/coffee and then informal gatherings at local venues)

ROOM: TBA

ABSTRACT
Public compute clouds provide a flexible platform to host applications
as a set of appliances, e.g., web servers or databases. Each appliance
usually contains an OS kernel and userspace processes, within which
applications access resources via APIs such as POSIX.  The flexible
architecture of the cloud comes at a cost: the addition of another
layer in the already complex software stack. This reduces performance and
increases the size of the trusted computing base. Continue reading

Event details

  • When: 19th February 2013 14:30 - 15:30
  • Format: Seminar

SACHI Seminar: A neurodynamical model of luminance perception by Olivier Penacchio

SACHI seminar

Title: A neurodynamical model of luminance perception

Speaker: Olivier Penacchio, University of St Andrews

Abstract:
The perception of such simple visual features as black, greys and white may sound simple. However, the luminance we perceive, also called brightness, does not match the luminance as physically measured. Instead, the perceived intensity of an area is modulated by the luminance of surrounding areas. This phenomenon is known as brightness induction and provides a striking demonstration that visual perception cannot be considered a simple pixel-wise sampling of the environment.

The talk will start with an overview of the classical examples of brightness induction and a quick look at the different theories underlying this phenomenon. We will next introduce a neurodynamical model of brightness induction, recently published*. This model is based on the architecture of the primary visual cortex and successfully accounts for well-known psychophysical effects both in static and dynamic contexts. It suggests that a common simple mechanism may underlie different fundamental processes of visual perception such as saliency and brightness perception. Finally, we will briefly outline potential applications in the arena of computer vision and medical imaging.
* Penacchio O, Otazu X, Dempere-Marco L (2013) A Neurodynamical Model of Brightness Induction in V1. PLoS ONE 8(5): e64086. doi:10.1371/journal.pone.0064086

Event details

  • When: 11th June 2013 13:00 - 14:00
  • Where: Cole 1.33a
  • Format: Seminar

SACHI Seminar: Modeling and Analyzing development of scripts by Vinodh Rajan

SACHI Seminar

Title:

Modeling and Analyzing development of scripts

Speaker: Vinodh Rajan, University of St. Andrews

Abstract:
Human handwriting is a process that often generates variable output. Scripts generally begin with characters possessing consistent shape. But the effects of variations tend to accumulate and modify the scripts’ appearance over time. The talk will start with a brief overview of scripts and related concepts. Then the example of the Brahmic family of scripts will be addressed, and in particular the variations that led to their development.This will be followed by a general introduction to handwriting modeling methods along with techniques such as trajectory reconstruction, stroke segmentation and stroke modeling. There will further be a discussion of methods and techniques to model and analyze development of scripts, with prospective applications, and lastly there will be a demo of what was achieved so far.

Bio:
Vinodh Rajan is a PhD student based within the School of Computing, here at the University of St. Andrews. Read more about Vinodh here.

Event details

  • When: 28th May 2013 13:00 - 14:00
  • Where: Cole 1.33a
  • Format: Seminar

SACHI Seminar: The SUM framework by Kyle Montague

SACHI Seminar

Title:

The SUM framework: An Exploration of Shared User Models and Adaptive Interfaces to Improve Accessibility of Touchscreen Interactions

Speaker: Kyle Montague, University of Dundee

Abstract:
Touchscreens are ever-present in technologies today. The large featureless sensors are rapidly replacing the physical keys and buttons on a wide array of digital technologies, the most common is the mobile device. Gaining popularity across all demographics and endorsed for their superior interface soft design flexibility and rich gestural interactions, the touchscreen currently plays a pivotal role in digital technologies. However, just as touchscreens have enabled many to engage with digital technologies, its barriers to access are excluding many others with visual and motor impairments. Continue reading

Event details

  • When: 14th May 2013 13:00 - 14:00
  • Where: Cole 1.33a
  • Format: Seminar