11,873 research outputs found

    The game jam movement:disruption, performance and artwork

    Get PDF
    This paper explores the current conventions and intentions of the game jam - contemporary events that encourage the rapid, collaborative creation of game design prototypes. Game jams are often renowned for their capacity to encourage creativity and the development of alternative, innovative game designs. However, there is a growing necessity for game jams to continue to challenge traditional development practices through evolving new formats and perspectives to maintain the game jam as a disruptive, refreshing aspect of game development culture. As in other creative jam style events, a game jam is not only a process but also, an outcome. Through a discussion of the literature this paper establishes a theoretical basis with which to analyse game jams as disruptive, performative processes that result in original creative artefacts. In support of this, case study analysis of Development Cultures: a series of workshops that centred on innovation and new forms of practice through play, chance, and experimentation, is presented. The findings indicate that game jams can be considered as processes that inspire creativity within a community and that the resulting performances can be considered as a form of creative artefact, thus parallels can be drawn between game jams and performative and interactive art

    Industrial laser welding: An evaluation

    Get PDF
    Report describes 10-kW laser welding system, designed to weld large structures made from 1/4-inch and 1/2-inch aluminum (2219) and D6AC steel

    The Herschel SPIRE Fourier Transform Spectrometer Spectral Feature Finder II. Estimating Radial Velocity of SPIRE Spectral Observation Sources

    Full text link
    The Herschel SPIRE FTS Spectral Feature Finder (FF) detects significant spectral features within SPIRE spectra and employs two routines, and external references, to estimate source radial velocity. The first routine is based on the identification of rotational CO emission, the second cross-correlates detected features with a line template containing most of the characteristic lines in typical far infra-red observations. In this paper, we outline and validate these routines, summarise the results as they pertain to the FF, and comment on how external references were incorporated.Comment: 12 pages, 16 figures, 1 table, accepted by MNRAS March 202

    Laser frequency comb techniques for precise astronomical spectroscopy

    Full text link
    Precise astronomical spectroscopic analyses routinely assume that individual pixels in charge-coupled devices (CCDs) have uniform sensitivity to photons. Intra-pixel sensitivity (IPS) variations may already cause small systematic errors in, for example, studies of extra-solar planets via stellar radial velocities and cosmological variability in fundamental constants via quasar spectroscopy, but future experiments requiring velocity precisions approaching ~1 cm/s will be more strongly affected. Laser frequency combs have been shown to provide highly precise wavelength calibration for astronomical spectrographs, but here we show that they can also be used to measure IPS variations in astronomical CCDs in situ. We successfully tested a laser frequency comb system on the Ultra-High Resolution Facility spectrograph at the Anglo-Australian Telescope. By modelling the 2-dimensional comb signal recorded in a single CCD exposure, we find that the average IPS deviates by <8 per cent if it is assumed to vary symmetrically about the pixel centre. We also demonstrate that series of comb exposures with absolutely known offsets between them can yield tighter constraints on symmetric IPS variations from ~100 pixels. We discuss measurement of asymmetric IPS variations and absolute wavelength calibration of astronomical spectrographs and CCDs using frequency combs.Comment: 11 pages, 7 figures. Accepted for publication in MNRA

    SN 2016iet: The Pulsational or Pair Instability Explosion of a Low Metallicity Massive CO Core Embedded in a Dense Hydrogen-Poor Circumstellar Medium

    Full text link
    We present optical photometry and spectroscopy of SN 2016iet, an unprecedented Type I supernova (SN) at z=0.0676z=0.0676 with no obvious analog in the existing literature. The peculiar light curve has two roughly equal brightness peaks (19\approx -19 mag) separated by 100 days, and a subsequent slow decline by 5 mag in 650 rest-frame days. The spectra are dominated by emission lines of calcium and oxygen, with a width of only 34003400 km s1^{-1}, superposed on a strong blue continuum in the first year, and with a large ratio of L[CaII]/L[OI]4L_{\rm [Ca\,II]}/L_{\rm [O\,I]}\approx 4 at late times. There is no clear evidence for hydrogen or helium associated with the SN at any phase. We model the light curves with several potential energy sources: radioactive decay, central engine, and circumstellar medium (CSM) interaction. Regardless of the model, the inferred progenitor mass near the end of its life (i.e., CO core mass) is 55\gtrsim 55 M_\odot and up to 120120 M_\odot, placing the event in the regime of pulsational pair instability supernovae (PPISNe) or pair instability supernovae (PISNe). The models of CSM interaction provide the most consistent explanation for the light curves and spectra, and require a CSM mass of 35\approx 35 M_\odot ejected in the final decade before explosion. We further find that SN 2016iet is located at an unusually large offset (16.516.5 kpc) from its low metallicity dwarf host galaxy (Z0.1Z\approx 0.1 Z_\odot, M108.5M\approx 10^{8.5} M_\odot), supporting the PPISN/PISN interpretation. In the final spectrum, we detect narrow Hα\alpha emission at the SN location, likely due to a dim underlying galaxy host or an H II region. Despite the overall consistency of the SN and its unusual environment with PPISNe and PISNe, we find that the inferred properties of SN\,2016iet challenge existing models of such events.Comment: 26 Pages, 17 Figures, Submitted to Ap

    Tradition and Prudence in Locke's Exceptions to Toleration

    Get PDF
    Why did Locke exclude Catholics and atheists from toleration? Not, I contend, because he was trapped by his context, but because his prudential approach and practica ljudgments led him to traditiona ltexts. I make this argumentfirst by outlining the connections among prudential exceptionality, practical judgments, and traditional texts. I then describe important continuities betweenc onventional English understandings of the relationship between state and religion and Locke's writings on toleration, discuss Locke's conception of rights, and illustrate his use of prudential exceptions and distinctions. I conclude by arguing that Locke's problems are relevant to assessingc ontemporary liberal discussions of tolerationa nd the separation of state and religion that lean heavily on practical justification

    The development of a new measure of quality of life in the management of gastro-oesophageal reflux disease: the Reflux Questionnaire.

    Get PDF
    INTRODUCTION This paper reports on the development of a new measure of health-related quality of life for use among patients with gastro-oesophageal reflux disease (GORD), funded as part of the REFLUX trial. This is a large UK multi centre trial that aims to compare the clinical and cost effectiveness of minimal access surgery with best medical treatment for patients with GORD within the NHS. Method Potential items were identified via a series of interviews and focus groups carried out with patients who were receiving/had received medical or surgical treatment for GORD. The final measure consisted of 31 items covering 7 categories (Heartburn; Acid reflux; Wind; Eating and swallowing; Bowel movements; Sleep; Work, physical and social activities). The measure produced two outputs: a quality of life score (RQLS) and five Reflux symptom scores. Reliability (internal consistency), criterion validity with the SF-36 and, sensitivity to change in terms of relationship with reported change in prescribed medication were assessed amongst a sample of 794 patients recruited into the trial. RESULTS The measure was shown to be internally consistent, to show criterion validity with the SF-36 and sensitive to changes in patients use of prescribed medication at baseline and 3 month follow-up. DISCUSSION The Reflux questionnaire is a new self-administered questionnaire for use amongst patients with GORD. Initial findings suggest that the new measure is valid, reliable, acceptable to respondents and simple to administer in both a clinical and research context

    Global parameter search reveals design principles of the mammalian circadian clock

    Get PDF
    Background: Virtually all living organisms have evolved a circadian (~24 hour) clock that controls physiological and behavioural processes with exquisite precision throughout the day/night cycle. The suprachiasmatic nucleus (SCN), which generates these ~24 h rhythms in mammals, consists of several thousand neurons. Each neuron contains a gene-regulatory network generating molecular oscillations, and the individual neuron oscillations are synchronised by intercellular coupling, presumably via neurotransmitters. Although this basic mechanism is currently accepted and has been recapitulated in mathematical models, several fundamental questions about the design principles of the SCN remain little understood. For example, a remarkable property of the SCN is that the phase of the SCN rhythm resets rapidly after a 'jet lag' type experiment, i.e. when the light/ dark (LD) cycle is abruptly advanced or delayed by several hours. Results: Here, we describe an extensive parameter optimization of a previously constructed simplified model of the SCN in order to further understand its design principles. By examining the top 50 solutions from the parameter optimization, we show that the neurotransmitters' role in generating the molecular circadian rhythms is extremely important. In addition, we show that when a neurotransmitter drives the rhythm of a system of coupled damped oscillators, it exhibits very robust synchronization and is much more easily entrained to light/dark cycles. We were also able to recreate in our simulations the fast rhythm resetting seen after a 'jet lag' type experiment. Conclusion: Our work shows that a careful exploration of parameter space for even an extremely simplified model of the mammalian clock can reveal unexpected behaviours and non-trivial predictions. Our results suggest that the neurotransmitter feedback loop plays a crucial role in the robustness and phase resetting properties of the mammalian clock, even at the single neuron level

    Conversion and Extraction of Insoluble Organic Materials in Meteorites

    Get PDF
    We endeavor to develop and implement methods in our laboratory to convert and extract insoluble organic materials (IOM) from low car-bon bearing meteorites (such as ordinary chondrites) and Precambrian terrestrial rocks for the purpose of determining IOM structure and prebiotic chemistries preserved in these types of samples. The general scheme of converting and extracting IOM in samples is summarized in Figure 1. First, powdered samples are solvent extracted in a micro-Soxhlet apparatus multiple times using solvents ranging from non-polar to polar (hexane - non-polar, dichloromethane - non-polar to polar, methanol - polar protic, and acetonitrile - polar aprotic). Second, solid residue from solvent extractions is processed using strong acids, hydrochloric and hydrofluoric, to dissolve minerals and isolate IOM. Third, the isolated IOM is subjected to both thermal (pyrolysis) and chemical (oxidation) degradation to release compounds from the macromolecular material. Finally, products from oxidation and pyrolysis are analyzed by gas chromatography - mass spectrometry (GCMS). We are working toward an integrated method and analysis scheme that will allow us to determine prebiotic chemistries in ordinary chondrites and Precambrian terrestrial rocks. Powerful techniques that we are including are stepwise, flash, and gradual pyrolysis and ruthenium tetroxide oxidation. More details of the integrated scheme will be presented

    Formal change impact analyses for emulated control software

    Get PDF
    Processor emulators are a software tool for allowing legacy computer programs to be executed on a modern processor. In the past emulators have been used in trivial applications such as maintenance of video games. Now, however, processor emulation is being applied to safety-critical control systems, including military avionics. These applications demand utmost guarantees of correctness, but no verification techniques exist for proving that an emulated system preserves the original system’s functional and timing properties. Here we show how this can be done by combining concepts previously used for reasoning about real-time program compilation, coupled with an understanding of the new and old software architectures. In particular, we show how both the old and new systems can be given a common semantics, thus allowing their behaviours to be compared directly
    corecore