Comment on "Equivalence of the variational matrix product method and the density matrix renormalization group applied to spin chains"

Dukelsky, Mart\'in-Delgado, Nishino and Sierra (Europhys. Lett., 43, 457 (1998) - hereafter referred to as DMNS) investigated the matrix product method (MPM), comparing it with the infinite-size density matrix renormalization group (DMRG). For equivalent basis size, the MPM produces an improved variational energy over that produced by DMRG and, unlike DMRG, produces a translationally-invariant wavefunction. The DMRG results presented were significantly worse than the MPM, caused by a shallow bound state appearing at the join of the two DMRG blocks. They also suggested that the DMRG results can be improved by using an alternate superblock construction $[B] \bullet [B]$ for the last few steps of the calculation. In this comment, we show that the DMRG results presented by DMNS are in error and the artificial bound state produced by the standard superblock configuration is very small even for $m=2$ states kept. In addition, we calculate explicitly the energy and wavefunction for the $[B] \bullet [B]$ superblock structure and verify that the energy coincides with that of the MPM, as conjectured by S. Ostlund and S. Rommer (Phys. Rev. Lett., 75, 3537 (1995)).Comment: 2 pages, 1 eps figure included. eps.cls include

The e-Framework and a service oriented approach

Article describing the JISC e-Framework, which is intended to assist educational institutions and research organisations to "harness the potential of ICT to realise their strategic goals" by recognising that there are benefits to be gained from the use of small modular tools and web services that can be combined and applied in different ways

An analytical approach to modelling epidemics on networks : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Applied Mathematics at Massey University, Albany, New Zealand

A significant amount of effort has been directed at understanding how the structure of a contact network can impact the spread of an infection through a population. This thesis is focused on obtaining tractable analytic results to aid our understanding of how infections spread through contact networks and to contribute to the existing body of research that is aimed at determining exact epidemic results on finite networks. We use SIR (Susceptible-Infected-Recovered) and SIS (Susceptible- Infected-Susceptible) models to investigate the impact network topology has on the spread of an infection through a population. For an SIR model, the probability mass functions of the final epidemic size are derived for eight small networks of different topological structure. Results from the small networks are used to illustrate how it is possible to describe how an infection spreads through a larger network, namely a line of triangles network. The key here is to correctly decompose the larger network into an appropriate assemblage of small networks so that the results are exact. We use Markov Chain theory to derive results for an SIS model on eight small networks such as the expected time to absorption, the expected number of times each individual is infected and the cumulative incidence of the epidemic. An algorithm to derive the transition matrix for any small network structure is presented, from which, in theory, all other results for the SIS model can be obtained using Markov Chain theory. In theory, this algorithm is applicable to networks of any size, however in practice it is too computationally intensive to be practical for larger networks than those presented in this thesis. We give examples for both types of model and illustrate how to parameterise the small networks to investigate the spread of influenza, measles, rabies and chlamydia through a small community or population

Thesauri : practical guidance for construction

Purpose - With the growing recognition that thesauri aid information retrieval, organisations are beginning to adopt, and in many cases, create thesauri. This paper offers some guidance on the construction process. Design/methodology/approach - An opinion piece with a practical focus, based on recent experiences gleaned from consultancy work. Findings - A number of steps can be taken to ensure any thesaurus under construction is fit for purpose. Due consideration is therefore given to aspects such as term selection, structure and notation, thesauri standards, software and Web display issues, thesauri evaluation and maintenance. This paper also notes that creating new subject schemes from scratch, however attractive, contributes to the plethora of terminologies currently in existence and can limit user searching within particular contexts. The decision to create a "new" thesaurus should therefore be taken carefully and observance of standards is paramount. Practical implications - This paper offers advice to assist practitioners in the development of thesauri. Originality/value - Useful guidance for those practitioners new to the area of thesaurus construction is provided, together with an overview of selected key processes involved in the construction of a thesaurus

"'Most People Bring Their Own Spoons': THE ROOM's participatory audiences as comedy mediators"

THE ROOM (Tommy Wiseau, 2003) has developed the unenviable reputation as being one of the worst films ever made, yet at the same time is celebrated by ‘fans’ who take considerable pleasure from its perceived ineptitude. Considerable media attention has also been afforded to the film’s participatory theatrical screenings, which typically feature constant heckling, chants, and the throwing of plastic spoons. Through the analysis of the film’s British audiences (in the form of surveys, interviews, observation and autoethnography), this article argues that The Room demonstrates the impact of audience participation on a film’s reception, which in this case transforms an ostensible drama into a comedy experience. These audiences function as temporary communities that encourage the search for humour in ‘badness’, creating a cycle of comedy mediation and verification that affirms the interpretive competence of all attendees. The article begins to theorise the previously underdeveloped concept of ‘so bad it’s good’ by drawing a link between comedy and cult media audiences, as well as exploring the social functions of comedy as they relate to cultural texts

“Within Ourselves”: The Development of British Light Infantry in North America during the Seven Years’ War

The first British regulars to appear in North America were those accompanying a small British expedition to wrest Manhattan from the Dutch in 1664. Colonel Richard Nicolls’ troops landed on Long Island 25 August 1664 at the exact site where General William Howe’s troops would disembark over a century later. After a swift Dutch capitulation, Nicolls’ redcoats and subsequent garrisons of British regulars would maintain a solid presence in New York for a virtually uninterrupted period of 119 years. It has been suggested by one American historian that this factual record has been conveniently overlooked by most of his colleagues in order that “the dismal episode of Braddock’s defeat” can figure prominently in history books as the first appearance of British redcoats on the North American scene. Thus “they could be made to appear as stupid brutes led by an eighteenth century Colonel Blimp while American militia simultaneously appeared as a keen and valiant yeomanry led by that paragon of all virtue and destined military hero of the fight for American liberty, George Washington.” His accusation is a valid one, but not very surprising, as much of early American history has become firmly embedded in myth, legend and folklore. “Braddock’s Defeat,” “The Massacre at Fort William Henry,” “The Boston Massacre” and even “George Washington’s Cutting Down the Cherry Tree” have all served a variety of purposes down through the centuries. All have become part of the “usable past” and have been extensively deployed in any discussions of one of those favourite themes of North American historians—the conflict between European and colonial values and methods. Inevitably European warfare vs. North American warfare (la petite guerre) has been drawn into the mythic vortex. Canadian historian I.K. Steele writes that “North American pride in the ways of the New World has often led to the assumption that, in warfare as in everything else, the new men of the New World were better than the history-laden men of the Old.” Braddock’s defeat more than any other engagement of the Seven Years’ War has, “with some misrepresentation,” been used as key evidence to support this assumption of superiority. Stanley Pargellis reinforces this view: Military historians hold that Braddock’s defeat taught a lesson badly needed for the time: you cannot employ parade ground tactics in the bush. To almost everyone who in one connection or another remembers Braddock, this episode stands as a conflict between Old World and New World ways, with the outcome justifying the new. However, many historians led by Pargellis, with Paul Koppermans, Ian Strachan, and Steele in close support, stress that Braddock’s defeat can no longer be perceived or used as such. While broad generalizations about the utility of close-order formations in woods or the cunning and ruthlessness of Indian tactics or the command abilities of the young Washington may all be still true, they are not true as inferences from Braddock’s defeat. The general consensus now is that Braddock’s debacle was precipitated in large part by his critical neglect on the day of battle to observe the fundamental rules of war laid down in the European manuals of the day. His leadership lapse and complacency once nearing his objective meant that his soldiers were never given a chance to demonstrate that Old World methods, properly applied, might have very well won the day. His column from the day it launched into the North American wilderness adopted well-conceived and generally well-executed security measures as per the manuals. On the day however, these careful measures were inexplicably not ordered nor implemented by Braddock and his staff and their absence was enough to ensure the ruin of their army and give British officers a reputation for ineptitude under frontier conditions. This reputation is undeserved, for British regulars took especial care to prepare themselves for the American theatre, including Braddock and subsequent commanders. After Braddock’s defeat no inferior guerilla force would ever overcome any substantial body of British regulars during the Seven Years’ War in North America

Not hearing us: An exploration of the experience of deaf prisoners in English and Welsh prisons

This research explores the experiences of profoundly deaf prisoners in England and Wales. It analyses current provisions for deaf prisoners and uses interviews and case studies to investigate the manner in which provision is delivered in order to make a set of recommendations for improving the treatment of deaf people in prison