271 research outputs found

    Envisioning a Community Exemplar for Sustainability in and by ICT

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    We understand sustainability as a perspective on the performance of various kinds of systems that puts human well-being in the center of focus. Recognizing that information and communication technology (ICT) is shaping our modern society, there is a need to understand the impact of ICT on sustainability. On the one hand this can be achieved, for example, by extending classic software development approaches to cover sustainability issues. This can be coined sustainability in ICT. On the other hand, innovative ICT approaches offer the potential of directly addressing sustainability issues (sustainability by ICT). Within the ICT4S community, both perspectives are addressed. What is missing, is an overarching perspective that helps to identify interlinkages. In this contribution, we present the case of an online-shop selling ICT hardware products as an community exemplar. We exemplify the usefulness as an overarching example, by relating parts of our existing work on ICT sustainability to it: a process model of the sales process, as well as a representation of sustainability risks related to the sold ICT products. Additionally, we show how ICT4S papers from 2016 can be mapped to the exemplar. We conclude with presenting a community website, where we invite fellow researchers and practitioners to contribute to a growing wealth of sustainability insights

    Evaluation of Social Value Icons for a Domain-Specific Modeling Language

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    The Different Stages of PRPD Pattern for Positive Point to Plane Corona Driven by a dc Voltage Containing a Ripple

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    The different phase resolved partial discharge patterns, which can be recognized when a positive dc voltage containing a ripple due to a half-wave rectification is used are presented in this paper. Results are given from corona onset to the appearance of breakdown streamers. The outcomes are five different patterns, which represent the four stages of positive corona and their transition zones. Three of them are clearly identifiable with respect to patterns from other discharge sources that have already been reported for dc voltages containing a ripple. For an assessment of pattern formation discharge pulses as recorded at the test object are presented. Finally, the appearance of patterns is explained with support of the measured discharge pulses and the underlying physical processes

    The different stages of PRPD pattern for negative point to plane corona driven by a DC voltage containing a ripple

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    This paper presents the different patterns, which can be observed by means of a phase resolved partial discharge analysis, when a negative dc voltage is applied to a point to plane arrangement in air. The required phase relation is obtained due to the ripple being present on the dc voltage generated by a half-wave rectification. Phase resolved partial discharge patterns are given from corona onset to glow inception. Discharge pulses appearing at the test object are used to support physical explanations of the pattern occurrence. It is shown that five clearly identifiable patterns accompany the evolution of corona discharges when a dc voltage with a ripple is used. The uniqueness of the different patterns and the accompanied reduction in test effort for dc partial discharges is emphasized

    An Equivalent Circuit for Corona Discharges Caused by a Point to Plane Arrangement at ac, dc and Combined Voltages

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    In this paper a new two stage equivalent circuit for corona discharges is introduced. Its aim is to fill the gap between complexity of the circuit and accurate representation of the physical properties, which underlay a corona discharge. The first stage represents the voltage distribution and the occurrence of a discharge with respect to the applied voltage. The second stage models the physical discharge behavior like ionization, number of electrons, positive and negative ions as well as their interaction. The proposed circuit is able to model the different modes of corona discharges, which is experimentally verified. The simulation results are in good agreement with the measured results but cannot compete with simulations based on solving continuity equations. Nevertheless, due to the solely basement on network theory, it provides an easy access to the occurring physical effects during a corona discharge for all electrical engineers

    Pathways to Greener Pastures: Research Opportunities to Integrate Life Cycle Assessment and Sustainable Business Process Management Based on a Systematic Tertiary Literature Review

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    Sustainable Business Process Management (BPM) is a research field that aims to improve the sustainability performance of organizations’ operations. With its focus on business processes, it has the potential to bring sustainability considerations from external reporting to the core of organizations. We present a systematic tertiary literature study to provide a catalog of existing literature reviews and primary work and to give a consolidated overview of the state and research needs of the field. We find that Sustainable BPM research has focused on modeling approaches and most of the work so far is largely conceptual, with a limited sustainability perspective. Based on these findings, we propose an integration of BPM and Life Cycle Assessment (LCA), an established and rigorous method for sustainability analysis. We present research opportunities to show how both disciplines can synergize and leverage methods and techniques for business process automation and innovation to effectively improve the sustainability performance of organizations

    Excitonic recombinations in hBN: from bulk to exfoliated layers

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    Hexagonal boron nitride (h-BN) and graphite are structurally similar but with very different properties. Their combination in graphene-based devices meets now a huge research focus, and it becomes particularly important to evaluate the role played by crystalline defects in them. In this work, the cathodoluminescence (CL) properties of hexagonal boron nitride crystallites are reported and compared to those of nanosheets mechanically exfoliated from them. First the link between the presence of structural defects and the recombination intensity of bound-excitons, the so-called D series, is confirmed. Low defective h-BN regions are further evidenced by CL spectral mapping (hyperspectral imaging), allowing us to observe new features in the near-band-edge region, tentatively attributed to phonon replica of exciton recombinations. Second the h-BN thickness was reduced down to six atomic layers, using mechanical exfoliation, as evidenced by atomic force microscopy. Even at these low thicknesses, the luminescence remains intense and exciton recombination energies are not strongly modified with respect to the bulk, as expected from theoretical calculations indicating extremely compact excitons in h-BN

    Citizen Empowerment by a Technical Approach for Privacy Enforcement

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    It is a fundamental right of every natural person to control which personal information is collected, stored and processed by whom, for what purposes and how long. In fact, many (cloud based) services can only be used if the user allows them broad data collection and analysis. Often, users can only decide to either give their data or not to participate in communities. The refusal to provide personal data results in significant drawbacks for social interaction. That is why we believe that there is a need for tools to control one\u27s own data in an easy and effective way as protection against economic interest of global companies and their cloud computing systems (as data collector from apps, mobiles and services). Especially, as nowadays everybody is permanently online using different services and devices, users are often lacking the means to effectively control the access to their private data. Therefore, we present an approach to manage and distribute privacy settings: PRIVACY-AVARE is intended to enable users to centrally determine their data protection preferences and to apply them on different devices. Thus, users gain control over their data when using cloud based services. In this paper, we present the main idea of PRIVACY-AVARE

    TracyML - A Modeling Language for Social Impacts of Product Life Cycles

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    In order to analyse the impacts of production and consumption on social sustainability, Social Life Cycle Assessment (S-LCA) has emerged as an extensive and promising, yet still young methodology. S-LCA captures the whole life cycle of a product and aims to include all relevant affected stakeholders. It therefore requires large amounts of data and produces likewise complex results, which makes the presentation of findings challenging. We argue that conceptual models make the complexity of S-LCA study results easier to handle. In particular, Domain-Specific Modeling Languages (DSML) support users in structuring and communicating a complex problem domain. This paper presents TracyML, a DSML which provides transparency of social impacts associated with a product’s life cycle. Special emphasis has been laid on the graphical notation and understandability of the resulting models. We have evaluated the utility of TracyML by performing interviews with domain experts
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