8,067 research outputs found

    Alpha Entanglement Codes: Practical Erasure Codes to Archive Data in Unreliable Environments

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    Data centres that use consumer-grade disks drives and distributed peer-to-peer systems are unreliable environments to archive data without enough redundancy. Most redundancy schemes are not completely effective for providing high availability, durability and integrity in the long-term. We propose alpha entanglement codes, a mechanism that creates a virtual layer of highly interconnected storage devices to propagate redundant information across a large scale storage system. Our motivation is to design flexible and practical erasure codes with high fault-tolerance to improve data durability and availability even in catastrophic scenarios. By flexible and practical, we mean code settings that can be adapted to future requirements and practical implementations with reasonable trade-offs between security, resource usage and performance. The codes have three parameters. Alpha increases storage overhead linearly but increases the possible paths to recover data exponentially. Two other parameters increase fault-tolerance even further without the need of additional storage. As a result, an entangled storage system can provide high availability, durability and offer additional integrity: it is more difficult to modify data undetectably. We evaluate how several redundancy schemes perform in unreliable environments and show that alpha entanglement codes are flexible and practical codes. Remarkably, they excel at code locality, hence, they reduce repair costs and become less dependent on storage locations with poor availability. Our solution outperforms Reed-Solomon codes in many disaster recovery scenarios.Comment: The publication has 12 pages and 13 figures. This work was partially supported by Swiss National Science Foundation SNSF Doc.Mobility 162014, 2018 48th Annual IEEE/IFIP International Conference on Dependable Systems and Networks (DSN

    Technical principles for institutional technologies

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    Report and Recommendations From the Scholarly Publishing Roundtable

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    Report and Recommendations From the Scholarly Publishing Roundtable, January 201

    Testing in the incremental design and development of complex products

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    Testing is an important aspect of design and development which consumes significant time and resource in many companies. However, it has received less research attention than many other activities in product development, and especially, very few publications report empirical studies of engineering testing. Such studies are needed to establish the importance of testing and inform the development of pragmatic support methods. This paper combines insights from literature study with findings from three empirical studies of testing. The case studies concern incrementally developed complex products in the automotive domain. A description of testing practice as observed in these studies is provided, confirming that testing activities are used for multiple purposes depending on the context, and are intertwined with design from start to finish of the development process, not done after it as many models depict. Descriptive process models are developed to indicate some of the key insights, and opportunities for further research are suggested

    Changing Trains at Wigan: Digital Preservation and the Future of Scholarship

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    This paper examines the impact of the emerging digital landscape on long term access to material created in digital form and its use for research; it examines challenges, risks and expectations.

    The role of supply chain integration in achieving competitive advantage: A study of UK automobile manufacturers

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    The competitive nature of the global automobile industry has resulted in a battle for efficiency and consistency in supply chain management (SCM). For manufacturers, the diversified network of suppliers represents more than just a production system; it is a strategic asset that must be managed, evaluated, and revised in order to attain competitive advantage. One capability that has become an increasingly essential means of alignment and assessment is supply chain integration (SCI). Through such practices, manufacturers create informational capital that is inimitable, yet transferrable, allowing suppliers to participate in a mutually-beneficial system of performance-centred outcomes. From cost reduction to time improvements to quality control, the benefits of SCI extend throughout the supply chain lifecycle, providing firms with improved predictability, flexibility, and responsiveness. Yet in spite of such benefits, key limitations including exposure to risks, supplier failures, or changing competitive conditions may expose manufacturers to a vulnerable position that can severely impact value and performance. The current study summarizes the perspectives and predictions of managers within the automobile industry in the UK, highlighting a dynamic model of interdependency and interpolation that embraces SCI as a strategic resource. Full commitment to integration is critical to achieving improved outcomes and performance; therefore, firms seeking to integrate throughout their extended supply chain must be willing to embrace a less centralized locus of control

    Resilience of Digitally Connected Infrastructure Systems

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    Public or private economies of knowledge: The economics of diffusion and appropriation of bioinformatics tools

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    The past three decades have witnessed a period of great turbulence in the economies of biological knowledge, during which there has been great uncertainty as to how and where boundaries could be drawn between public or private knowledge especially with regard to the explosive growth in biological databases and their related bioinformatic tools. This paper will focus on some of the key software tools developed in relation to bio-databases. It will argue that bioinformatic tools are particularly economically unstable, and that there is a continuing tension and competition between their public and private modes of production, appropriation, distribution, and use. The paper adopts an ?instituted economic process? approach, and in this paper will elaborate on processes of making knowledge public in the creation of ?public goods?. The question is one of continuously creating and sustaining new institutions of the commons. We believe this critical to an understanding of the division and interdependency between public and private economies of knowledge

    Economic Autonomy of Regions in the New Reality

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    The article expands on the concept of new reality (new normal) for Russia, which includes the increased role of individuals and larger economic autonomy of territories in their interaction with the federal center. The rationale is based on the hypothesis that, in the new reality, the improved wellbeing of people and elimination of economic disparities between the territories can be ensured by expanding their economic autonomy, because it leads to the increase in their intellectual, industrial and technological capacity. In this study, the author used the basic provisions of the classical economic theory, the theory of behavioral economics, interdisciplinary approach, and the method of statistical groupings. The article presents the trends in the economic autonomy of the territories, which include a decrease in the number of donor regions and differentiation of territories in terms of their socio-economic indicators. It substantiates the assumption that the differentiation of territories puts constrains on their socio-economic development and may lead to the emergence of a «regional peripheral economy,» the attribute of which is the dependence of the periphery from the center, reduced local initiative, and slowdown of technological development. The article identi es the need to use the mindset of people, their psychological attitudes in the economic development, the «second invisible hand of the market» and «soft power» in order to move beyond the «regional peripheral economy.» The conducted study demonstrates that the expansion of economic autonomy of the territories is not the increased self-isolation of regions and municipal entities, but consists in the need to retain a signi cant part of the income from the production of goods and services created by local people, so that it could be autonomously used by regional and municipal authorities and directed to improving the wellbeing of territory’s residents.The author proposes to prepare a regulatory and legal document in order to ensure and strengthen the economic autonomy of the territories, and makes speci c proposals on the principles of its content and structure.This article has been prepared with the financial support of the Ural Branch of the Russian Academy of Sciences, Project No. 15–14–7-2

    AN AUTOMATIC AND METHODOLOGICAL APPROACH FOR ACCESSIBLE WEB APPLICATIONS

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    Semantic Web approaches try to get the interoperability and communication among technologies and organizations. Nevertheless, sometimes it is forgotten that the Web must be useful for every user, consequently it is necessary to include tools and techniques doing Semantic Web be accessible. Accessibility and usability are two usually joined concepts widely used in web application development, however their meaning are different. Usability means the way to make easy the use but accessibility is referred to the access possibility. For the first one, there are many well proved approaches in real cases. However, accessibility field requires a deeper research that will make feasible the access to disable people and also the access to novel non-disable people due to the cost to automate and maintain accessible applications. In this paper, we propose one architecture to achieve the accessibility in web-environments dealing with the WAI accessibility standard and the Universal Design paradigm. This architecture tries to control the accessibility in web applications development life-cycle following a methodology starting from a semantic conceptual model and leans on description languages and controlled vocabularies
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