Optimization of Generalized Multichannel Quantum Defect reference functions for Feshbach resonance characterization

This work stresses the importance of the choice of the set of reference functions in the Generalized Multichannel Quantum Defect Theory to analyze the location and the width of Feshbach resonance occurring in collisional cross-sections. This is illustrated on the photoassociation of cold rubidium atom pairs, which is also modeled using the Mapped Fourier Grid Hamiltonian method combined with an optical potential. The specificity of the present example lies in a high density of quasi-bound states (closed channel) interacting with a dissociation continuum (open channel). We demonstrate that the optimization of the reference functions leads to quantum defects with a weak energy dependence across the relevant energy threshold. The main result of our paper is that the agreement between the both theoretical approaches is achieved only if optimized reference functions are used.Comment: submitte to Journal of Physics

A quantitative theory-versus-experiment comparison for the intense laser dissociation of H2+

A detailed theory-versus-experiment comparison is worked out for H$_2^+$ intense laser dissociation, based on angularly resolved photodissociation spectra recently recorded in H.Figger's group. As opposite to other experimental setups, it is an electric discharge (and not an optical excitation) that prepares the molecular ion, with the advantage for the theoretical approach, to neglect without lost of accuracy, the otherwise important ionization-dissociation competition. Abel transformation relates the dissociation probability starting from a single ro-vibrational state, to the probability of observing a hydrogen atom at a given pixel of the detector plate. Some statistics on initial ro-vibrational distributions, together with a spatial averaging over laser focus area, lead to photofragments kinetic spectra, with well separated peaks attributed to single vibrational levels. An excellent theory-versus-experiment agreement is reached not only for the kinetic spectra, but also for the angular distributions of fragments originating from two different vibrational levels resulting into more or less alignment. Some characteristic features can be interpreted in terms of basic mechanisms such as bond softening or vibrational trapping.Comment: submitted to PRA on 21.05.200

Characterizing a source of fission fragments for a gas jet

A model for the rate at which various primary fission products stop in the gas of the source chamber of a gas jet has been constructed. It describes the absorption of fission fragments in Al foils placed between the 235 U deposit and the gas chamber as well as the penetration of fragments through the gas. The model is based on reported ranges (mean values as a function of A and the dispersion in ranges) and measured activities of Kr and Xe.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43112/1/10967_2005_Article_BF02060552.pd

Digital copyright and disability discrimination: from braille books to bookshare

In Australia, blind people are able to access texts in braille and books on tape, but the demand for these media is decreasing. Blind people today are increasingly reliant on texts in electronic form, and these are much less readily available in Australia. Electronic texts are more portable and less cumbersome than large braille volumes, and are much faster to navigate than audio recordings. However, in Australia it is difficult for blind people to get access to a wide range of electronic texts and there exists no scheme enabling such access. At the same time sighted people are using electronic text and other digital media at an ever-increasing rate. In order to approximate the same level of access as sighted people, blind people require access to accessible electronic versions of all published material. The authors suggest that given the legal imperatives of Australia’s domestic legislation, treaty obligations and social values, that there exists a moral imperative to create a scheme providing blind people with access to digital print media

Pugwash : les physiciens, l’arme nucléaire, la responsabilité des scientifiques

National audienceDans les années qui suivirent la Seconde Guerre mondiale, les physiciens réalisèrent que la bombe qu’ils avaient construite était en train de leur échapper. Afin de promouvoir un usage pacifique de la science, ils fondèrent le Mouvement Pugwash, qui agit en coulisse en faveur de la paix dans le monde et a été l’un des instigateurs du traité sur la non-prolifération. Il a reçu en 1995 le prix Nobel de la Paix, et encore récemment a contribué à convaincre le gouvernement syrien de détruire ses armes chimiques.L’évolution actuelle est à l’ouverture, vers les scientifiques de toutes disciplines, mais aussi vers un large public qui doit être informé et associé à la réflexion sur les conditions de survie de l’humanité, et de sa survie en paix

Fan based production for computer games: User led innovation, the 'drift of value' and the negotiation of intellectual property rights

Copyright 2005 (The authors). Copyright © QUT. All rights reserved.Fan based or third party content creation has assumed an integral place in the multimillion dollar computer games industry. The emerging production ecology that involves new kinds of distributed organisations and ad-hoc networks epitomises the ‘drift of value’ from producer to consumer and allows us to understand how user-led innovation influences the creative industries. But the ability to control intellectual property rights in content production is critical to the power structures and social dynamic that are being created in this space. Trainz, a train simulation game released by Brisbane developer Auran, which relies heavily on fan created content for its success is used as a case study. The licence agreements between Auran and the fan creators are analysed in order to understand how the balance between the commercial and non-commercial is achieved and how the tension between open networks of collaboration and closed structures of commercial competitive environments are negotiated. It explains the intellectual property issues involved and highlights how the interface between copyright and contract will have a critical impact on this example of user led innovation.Humphreys Sal, Fitzgerald Brian, Banks John and Suzor Ni

Dead cats in the mail: Dallas Buyers Club and the emergence of the user in Australian intermediary copyright law

In this chapter, we provide an account of the burgeoning trend in Australian copyright case law towards a more sympathetic treatment of copyright users. Traditionally, Australian cases involving internet intermediaries have disregarded the interests of copyright users, treating the fundamental balance as being between protecting creative authors, on the one hand, and promoting technological innovation on the other. Users’ interests were therefore relegated to the sidelines. However, hints of judicial dissatisfaction with the copyright status quo have begun to appear in the case law. In this chapter, we discuss the subtle shifts in the Federal Court’s approach to copyright users as people rather than pirates, beginning around the turn of this last decade in EMI Songs Australia Pty Ltd v Larrikin Music Publishing Pty Ltd [2011] FCAFC 47 and Singtel Optus Pty Ltd v National Rugby League Investments Pty Ltd (No 2) [2012] FCA 34. We then turn to consider the recent Dallas Buyer Club litigation in Australia. We argue that the Dallas Buyers Club decisions are a significant development in the concept of user rights under Australian copyright law, and that the discretionary way in which the court drafted its order is an important foil against dubious rightsholder practices like speculative invoicing

Evaluating the legitimacy of platform governance: A review of research and a shared research agenda

This paper provides an overview of the key values that we argue should underpin an index of the legitimacy of the governance of online intermediaries. The aim is ultimately to allow scholars to rank the policies and practices of intermediaries against core human rights values and principles of legitimate governance in a way that enables comparison across different intermediaries and over time. This work builds on the efforts of a broad range of researchers already working to systematically investigate the governance of social media platforms and telecommunications intermediaries. In this paper, we present our review and analysis of the work that has been carried out to date, using the digital constitutionalism literature to identify opportunities for further research and collaboration

Misogynistic tweet detection: Modelling CNN with small datasets

Online abuse directed towards women on the social media platform such as Twitter has attracted considerable attention in recent years. An automated method to effectively identify misogynistic abuse could improve our understanding of the patterns, driving factors, and effectiveness of responses associated with abusive tweets over a sustained time period. However, training a neural network (NN) model with a small set of labelled data to detect misogynistic tweets is difficult. This is partly due to the complex nature of tweets which contain misogynistic content, and the vast number of parameters needed to be learned in a NN model. We have conducted a series of experiments to investigate how to train a NN model to detect misogynistic tweets effectively. In particular, we have customised and regularised a Convolutional Neural Network (CNN) architecture and shown that the word vectors pre-trained on a task-specific domain can be used to train a CNN model effectively when a small set of labelled data is available. A CNN model trained in this way yields an improved accuracy over the state-of-the-art models