5,455 research outputs found

    Rational's experience using Ada for very large systems

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    The experience using the Rational Environment has confirmed the advantages forseen when the project was started. Interactive syntatic and semantic information makes a tremendous difference in the ease of constructing programs and making changes to them. The ability to follow semantic references makes it easier to understand exisiting programs and the impact of changes. The integrated debugger makes it much easier to find bugs and test fixes quickly. Taken together, these facilites have helped greatly in reducing the impact of ongoing maintenance of the ability to produce a new code. Similar improvements are anticipated as the same level of integration and interactivity are achieved for configuration management and version control. The environment has also proven useful in introducing personnel to the project and existing personnel to new parts of the system. Personnel benefit from the assistance with syntax and semantics; everyone benefits from the ability to traverse and understand the structure of unfamiliar software. It is often possible for someone completely unfamiliar with a body of code to use these facilities, to understand it well enough to successfully with a body of code to use these facilities to understand it well enough to successfully diagnose and fix bugs in a matter of minutes

    Early Sydney punk : methods in visual ethnography

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    This thesis explores the recollections of participants who were part of a cohort associated with a small punk venue known as the Grand Hotel, which operated at Railway Square, Sydney, between 1977 and 1979. While Australia’s first-wave moment has been increasingly recognised within a growing body of literature on punk, it has been considered almost exclusively in a music context. This study emphasises the sociality of punk subculture which has been largely absent from the record. The thesis comprises a creative component based on a series of video-recorded interviews, and a written exegesis. The video production, titled Distorted: Reflections on early Sydney punk, was developed through methods drawn from ethnography and other qualitative methodologies. The work presents discussion on a range of social, personal and political concerns of late 1970s Sydney through the reflections of participants. As such, it is a visual ethnography with a research focus on the past and on memory as articulated in a present setting. The written component of the thesis discusses aspects of cultural studies and subcultural theory in relation to punk as experienced in a post-colonial space, which is framed within an analysis of anthropologically-oriented ethnography. The text then discusses in detail the methodological underpinnings of the research. It is here that I advance an approach to audiovisual production which utilises computer assisted data analysis software within an analytical and conceptual framework drawn from grounded theory and narrative analysis

    Identifying Image Manipulation Software from Image Features

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    As technology steadily increases in the field of image manipulation, determining which software was used to manipulate an image becomes increasingly complex for law enforcement and intelligence agencies. To combat this difficult problem, new techniques that examine the artifacts left behind by a specific manipulation are converted to features for classification. This research implemented four preexisting image manipulation detection techniques into a framework of modules: Two-Dimensional Second Derivative, One-Dimensional Zero Crossings, Quantization Matrices Identification, and File Metadata analysis. The intent is the creation of a framework to develop a capability to determine which specific image manipulation software program manipulated an image. The determination is based on each image manipulation software program having implemented the manipulation algorithms differently. These differences in the implementation will leave behind different artifacts in the resultant image. Experimental results demonstrate the framework\u27s ability to identify from the 48 combinations of image manipulation software programs, scaling, and the algorithm used with a true positive rate of 0.54, false positive rate of 0.01, and a Kappa statistic of 0.53 for Joint Photographic Experts Group (JPEG). The results for Tagged Image File Format (TIFF) images were a true positive rate of 0.53, false positive rate of 0.01, and a Kappa statistic of 0.52

    Accelerator measurement of the energy spectra of neutrons emitted in the interaction of 3-GeV protons with several elements

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    The application of time of flight techniques for determining the shapes of the energy spectra of neutrons between 20 and 400 MeV is discussed. The neutrons are emitted at 20, 34, and 90 degrees in the bombardment of targets by 3 GeV protons. The targets used are carbon, aluminum, cobalt, and platinum with cylindrical cross section. Targets being bombarded are located in the internal circulating beam of a particle accelerator

    Network-Based Criterion for the Success of Cooperation in an Evolutionary Prisoner\u27s Dilemma

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    We consider an evolutionary prisoner\u27s dilemma on a random network. We introduce a simple quantitative network-based parameter and show that it effectively predicts the success of cooperation in simulations on the network. The criterion is shown to be accurate on a variety of networks with degree distributions ranging from regular to Poisson to scale free. The parameter allows for comparisons of random networks regardless of their underlying topology. Finally, we draw analogies between the criterion for the success of cooperation introduced here and existing criteria in other contexts

    Reply To Comment on \u27Cooperation in an Evolutionary Prisoner\u27s Dilemma on Networks with Degree-Degree Correlations\u27 

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    We respond to the comment of Zhu et al. [Phys. Rev. E 82, 038101 (2010)] and show that the results in question are not misleading

    Evolution of Cooperation through the Heterogeneity of Random Networks

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    We use the standardized variance (nu_{st}) of the degree distribution of a random network as an analytic measure of its heterogeneity. We show that nu_{st} accurately predicts, quantitatively, the success of cooperators in an evolutionary prisoner\u27s dilemma. Moreover, we show how the generating functional expression for nu_{st} suggests an intrinsic interpretation for the heterogeneity of the network that helps explain local mechanisms through which cooperators thrive in heterogeneous populations. Finally, we give a simple relationship between nu_{st} , the cooperation level, and the epidemic threshold of a random network that reveals an appealing connection between epidemic disease models and the evolutionary prisoner\u27s dilemma

    Cooperation in an Evolutionary Prisoner\u27s Dilemma on Networks with Degree-Degree Correlations

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    We study the effects of degree-degree correlations on the success of cooperation in an evolutionary prisoner\u27s dilemma played on a random network. When degree-degree correlations are not present, the standardized variance of the network\u27s degree distribution has been shown to be an accurate analytical measure of network heterogeneity that can be used to predict the success of cooperation. In this paper, we use a local-mechanism interpretation of standardized variance to give a generalization to graphs with degree-degree correlations. Two distinct mechanisms are shown to influence cooperation levels on these types of networks. The first is an intrinsic measurement of base-line heterogeneity coming from the network\u27s degree distribution. The second is the increase in heterogeneity coming from the degree-degree correlations present in the network. A strong linear relationship is found between these two parameters and the average cooperation level in an evolutionary prisoner\u27s dilemma on a network

    Integrating visual and tactile information in the perirhinal cortex

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    By virtue of its widespread afferent projections, perirhinal cortex is thought to bind polymodal information into abstract object-level representations. Consistent with this proposal, deficits in cross-modal integration have been reported after perirhinal lesions in nonhuman primates. It is therefore surprising that imaging studies of humans have not observed perirhinal activation during visual–tactile object matching. Critically, however, these studies did not differentiate between congruent and incongruent trials. This is important because successful integration can only occur when polymodal information indicates a single object (congruent) rather than different objects (incongruent). We scanned neurologically intact individuals using functional magnetic resonance imaging (fMRI) while they matched shapes. We found higher perirhinal activation bilaterally for cross-modal (visual–tactile) than unimodal (visual–visual or tactile–tactile) matching, but only when visual and tactile attributes were congruent. Our results demonstrate that the human perirhinal cortex is involved in cross-modal, visual–tactile, integration and, thus, indicate a functional homology between human and monkey perirhinal cortices
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