3,836 research outputs found

    Evaluating some computer enhancement algorithms that improve the visibility of cometary morphology

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    The observed morphology of cometary comae is determined by ejection circumstances and the interaction of the ejected material with the local environment. Anisotropic emission can provide useful information on such things as orientation of the nucleus, location of active areas on the nucleus, and the formation of ion structure near the nucleus. However, discrete coma features are usually diffuse, of low amplitude, and superimposed on a steep intensity gradient radial to the nucleus. To improve the visibility of these features, a variety of digital enhancement algorithms were employed with varying degrees of success. They usually produce some degree of spatial filtering, and are chosen to optimize visibility of certain detail. Since information in the image is altered, it is important to understand the effects of parameter selection and processing artifacts can have on subsequent interpretation. Using the criteria that the ideal algorithm must enhance low contrast features while not introducing misleading artifacts (or features that cannot be seen in the stretched, unprocessed image), the suitability of various algorithms that aid cometary studies were assessed. The strong and weak points of each are identified in the context of maintaining positional integrity of features at the expense of photometric information

    A Landslide Climate Indicator from Machine Learning

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    In order to create a Landslide Hazard Index, we accessed rain, snow, and a dozen other variables from the National Climate Assessment Land Data Assimilation System. These predictors were converted to probabilities of landslide occurrence with XGBoost, a major machine-learning tool. The model was fitted with thousands of historical landslides from the Pacific Northwest Landslide Inventory (PNLI)

    Empirical Studies of Evolving Systems

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    This paper describes the results of the working group investigating the issues of empirical studies for evolving systems. The groups found that there were many issues that were central to successful evolution and this concluded that this is a very important area within software engineering. Finally nine main areas were selected for consideration. For each of these areas the central issues were identified as well as success factors. In some cases success stories were also described and the critical factors accounting for the success analysed. In some cases it was later found that a number of areas were so tightly coupled that it was important to discuss them together

    The poverty of journal publishing

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    The article opens with a critical analysis of the dominant business model of for-profit, academic publishing, arguing that the extraordinarily high profits of the big publishers are dependent upon a double appropriation that exploits both academic labour and universities’ financial resources. Against this model, we outline four possible responses: the further development of open access repositories, a fair trade model of publishing regulation, a renaissance of the university presses, and, finally, a move away from private, for-profit publishing companies toward autonomous journal publishing by editorial boards and academic associations. </jats:p

    Influences on academics' approaches to development: voices from below

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    The purpose of this qualitative case study research was to explore faculty-based academics’ views on what influences their behaviours and attitudes towards their development. Informed by critical realist ontology, the data collection was carried out through narrative interviews with academics in two contrasting English Universities. Findings, or areas for reflection, have emerged about the constraints and enablements academics perceive in respect of their professional development. In particular, themes such as the significance of professional status; misaligned initiatives and priorities; the influence of supportive networks; and emergent personal, individual concerns have surfaced. The conclusion is drawn that the significance of agency raises the importance of responding to the ‘voices from below’

    Patenting and licensing of university research: promoting innovation or undermining academic values?

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    Since the 1980s in the US and the 1990s in Europe, patenting and licensing activities by universities have massively increased. This is strongly encouraged by governments throughout the Western world. Many regard academic patenting as essential to achieve 'knowledge transfer' from academia to industry. This trend has far-reaching consequences for access to the fruits of academic research and so the question arises whether the current policies are indeed promoting innovation or whether they are instead a symptom of a pro-intellectual property (IP) culture which is blind to adverse effects. Addressing this question requires both empirical analysis (how real is the link between academic patenting and licensing and 'development' of academic research by industry?) and normative assessment (which justifications are given for the current policies and to what extent do they threaten important academic values?). After illustrating the major rise of academic patenting and licensing in the US and Europe and commenting on the increasing trend of 'upstream' patenting and the focus on exclusive as opposed to non-exclusive licences, this paper will discuss five negative effects of these trends. Subsequently, the question as to why policymakers seem to ignore these adverse effects will be addressed. Finally, a number of proposals for improving university policies will be made

    High-pressure x-ray diffraction and ab initio study of Ni2Mo3N, Pd2Mo3N, Pt2Mo3N, Co3Mo3N, and Fe3Mo3N: Two families of ultra-incompressible bimetallic interstitial nitrides

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    We have studied by means of high-pressure x-ray diffraction the structural stability of Ni2Mo3N, Co3Mo3N, and Fe3Mo3N. We also report ab initio computing modeling of the high-pressure properties of these compounds, Pd2Mo3N, and Pt2Mo3N. We have found that the nitrides remain stable in the ambient-pressure cubic structure at least up to 50 GPa and determined their equation of state. All of them have a bulk modulus larger than 300 GPa. Single-crystal elastic constants have been calculated in order to quantify the stiffness of the investigated nitrides. We found that they should have a Vickers hardness similar to that of cubic spinel nitrides like gamma-Si3N4Comment: 25 pages, 6 figures, 3 table
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