Resilient planning for sporting mega-events: designing and managing safe and secure urban places for London 2012 and beyond

Since the 1960s both regeneration and security have been prominent themes in Olympic planning. However, this paper argues that the prominence given to post event 'legacies' in London's bid to host the 2012 Summer Games has fomented a merger of these hitherto distinct ambitions oriented around notions of 'resilience'. In addition to identifying this merger, based on analysis of planning for the 2012 Games the paper sets out its component features and considers a range of key implications. These include the accommodation of Olympic security amid shifting national security arrangements and, at a local level, the impact and importance of the 2011 London riots on Olympic safety and security processes. Organised over four areas of discussion - the first three comprising of the coupling of spatial strategies of resilient planning and design with concerns for security; the temporal framework of such approaches; analysis of the altered physical and institutional landscape of London ahead of the 2012 Olympic Games - the paper concludes by identifying and discussing the ways in which urban rejuvenation and securitisation which are increasingly being combined into resilient designs and master plans in the Olympic context and, crucially, standardised, exported and transferred to new urban hosts of similar events

Mathematical models for chemotaxis and their applications in self-organisation phenomena

Chemotaxis is a fundamental guidance mechanism of cells and organisms, responsible for attracting microbes to food, embryonic cells into developing tissues, immune cells to infection sites, animals towards potential mates, and mathematicians into biology. The Patlak-Keller-Segel (PKS) system forms part of the bedrock of mathematical biology, a go-to-choice for modellers and analysts alike. For the former it is simple yet recapitulates numerous phenomena; the latter are attracted to these rich dynamics. Here I review the adoption of PKS systems when explaining self-organisation processes. I consider their foundation, returning to the initial efforts of Patlak and Keller and Segel, and briefly describe their patterning properties. Applications of PKS systems are considered in their diverse areas, including microbiology, development, immunology, cancer, ecology and crime. In each case a historical perspective is provided on the evidence for chemotactic behaviour, followed by a review of modelling efforts; a compendium of the models is included as an Appendix. Finally, a half-serious/half-tongue-in-cheek model is developed to explain how cliques form in academia. Assumptions in which scholars alter their research line according to available problems leads to clustering of academics and the formation of "hot" research topics.Comment: 35 pages, 8 figures, Submitted to Journal of Theoretical Biolog

Transition between immune and disease states in a cellular automaton model of clonal immune response

In this paper we extend the Celada-Seiden (CS) model of the humoral immune response to include infectious virus and cytotoxic T lymphocytes (cellular response). The response of the system to virus involves a competition between the ability of the virus to kill the host cells and the host's ability to eliminate the virus. We find two basins of attraction in the dynamics of this system, one is identified with disease and the other with the immune state. There is also an oscillating state that exists on the border of these two stable states. Fluctuations in the population of virus or antibody can end the oscillation and drive the system into one of the stable states. The introduction of mechanisms of cross-regulation between the two responses can bias the system towards one of them. We also study a mean field model, based on coupled maps, to investigate virus-like infections. This simple model reproduces the attractors for average populations observed in the cellular automaton. All the dynamical behavior connected to spatial extension is lost, as is the oscillating feature. Thus the mean field approximation introduced with coupled maps destroys oscillations.Comment: 27 pages LaTeX + 7 Figures Postscrip

MIXED LOGIT ESTIMATION OF RADICAL ISLAMIC TERRORISM IN EUROPE AND NORTH AMERICA: A COMPARATIVE STUDY

This paper estimates what characteristics (e.g. location, number of casualties, and type of attack) are associated with an Islamic terrorist attack. This is established by identifying the significant determinants of the probability that an attack had been carried out by Islamic terrorists. For Europe, the United States, and Canada, the analysis employs ITERATE data from October 1979 to December 2002 to ascertain the significant characteristics of Islamic terrorist attacks. A random- parameter logit model is used to analyze the probability of such attacks, taking into account the heterogeneity of the sample data. This model outperforms the standard logit model. Some policy implications are presented.Islamic radical terrorism, mixed logit model, and public policy

Localized quantum walks as secured quantum memory

We show that a quantum walk process can be used to construct and secure quantum memory. More precisely, we show that a localized quantum walk with temporal disorder can be engineered to store the information of a single, unknown qubit on a compact position space and faithfully recover it on demand. Since the localization occurss with a finite spread in position space, the stored information of the qubit will be naturally secured from the simple eavesdropper. Our protocol can be adopted to any quantum system for which experimental control over quantum walk dynamics can be achieved.Comment: 7 pages, 4 figure

Measuring Information Leakage in Website Fingerprinting Attacks and Defenses

Tor provides low-latency anonymous and uncensored network access against a local or network adversary. Due to the design choice to minimize traffic overhead (and increase the pool of potential users) Tor allows some information about the client's connections to leak. Attacks using (features extracted from) this information to infer the website a user visits are called Website Fingerprinting (WF) attacks. We develop a methodology and tools to measure the amount of leaked information about a website. We apply this tool to a comprehensive set of features extracted from a large set of websites and WF defense mechanisms, allowing us to make more fine-grained observations about WF attacks and defenses.Comment: In Proceedings of the 2018 ACM SIGSAC Conference on Computer and Communications Security (CCS '18