994 research outputs found

    Wither Interpretivism? Re-interpreting interpretation to fit a world of ubiquitous ICT

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    Interpretivism in IS emerged in the 1980s. While at the time it presented an important alternative to positivism, the world has changed significantly since then, raising questions about its efficacy for IS relevant to the emerging world of ubiquitous IT. Some have suggested it should be abandoned because of its dualist inheritance from positivism. In this paper we explore a less radical approach of replacing the notion of interpretation at the heart of the approach with a non-dualist alternative. We explore how its problematic commitments to dualism, mentalism and individualism might be overcome by re-interpreting ‘interpretation’ using the holistic notions of ‘equipment’, ‘world’ and ‘being-in-the-world’ drawn from recent non-dualist work in IS. Such an ‘evolved’ interpretivism would retain key elements of the received view but repair others, allowing the existing acceptance and knowledge of interpretivism to be leveraged rather than replaced

    On Putting the Score ahead of the Game

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    We support the call by Nik Hassan for a more nuanced account of the value of Information Systems (IS) research situated in “the intellectual ideals of the academic field, its goals and mission, intellectual structures activities and relationship with its environment” (paper in this issue). In this paper we examine the process by which this notion of ‘knowledge value’ is increasingly being marginalised in the IS discipline by more pragmatic measures of the value of research as a ‘product’ in certain academic ‘markets’. We argue that the increasing centrality that maximising this ‘product value’ assumes in the lives of IS academics helps make sense of the IS ‘discourses of anxiety’ that Nik Hassan documents. Further, the distortion of research practices that widely accepted ideologies of measurement and efficiency bring about, threatens to diminish the holistic knowledge value of research that Nik Hassan articulates. In short, we argue that we are at risk of putting the score ahead of the game. We make our case by showing that the mechanisms by which this value displacement is transpiring in IS, exhibit strong parallels to those that have been shown to underpin disastrous episodes of large-scale efficiency-motivated social reengineering more generally

    A parameterisation of the soot aging for global climate models

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    International audienceThe representation of soot in global climate models is desirable since it contributes to both the direct and indirect climate effect. While freshly emitted soot is initially hydrophobic and externally mixed, it can be transferred into an internal mixture by coagulation, condensation or photochemical processes. These aging processes affect the hygroscopic qualities and hence the growth behaviour, the optical properties and eventually the lifetime of the soot particles. However, due to computational limits the aging of soot in global climate models is often only parameterised by an estimated turnover rate resulting in a lifetime of soot of several days. Based on the results of our simulations with a comprehensive mesoscale model, we derive the timescale on which diesel soot is transferred from an external to internal mixture, and propose a parameterisation for the use in global climate models. This parameterisation is applicable to continental conditions in industrialised areas as can be found in Central Europe and North America. For daytime conditions, away from the sources, condensation is dominant and the aging process occurs very fast with a timescale of ?=2 h. During night time condensation is not effective. Then coagulation is the most important aging process and our parameterisation leads to a timescale between 10 h and 40 h

    Soot aging time scales in polluted regions during day and night

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    The aging of soot is one of the key uncertainties in the estimation of both the direct and indirect climate effect. While freshly emitted soot is initially hydrophobic and externally mixed, it can be transferred into an internal mixture by coagulation, condensation or photochemical processes. These aging processes affect the hygroscopic qualities and hence the growth behaviour, the optical properties and eventually the lifetime of the soot particles. However, due to computational limits the aging of soot in global climate models is often only parameterised by an estimated turnover rate resulting in a lifetime of soot of several days. Hence, the aging process of soot is one of the key uncertainties governing the burden and effect of black carbon. In this study, we discuss the time scale on which diesel soot is transferred from an external to an internal mixture based on the results of our simulations with a comprehensive mesoscale model. For daytime conditions during summer condensation of sulphuric acid is dominant and the aging process occurs on a time scale of τ =8h close to the sources and τ =2h above the source region. During winter comparable time scales are found but ammonium nitrate becomes more important. During night time condensation is not effective. Then coagulation is the most important aging process and our results show time scales between 10h and 40h

    Technology Introduction as Social Interpretation by End-Users: Key Articulations in the Literature

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    What happens after new technologies have been rolled out in organisations? Current literature studying technology introduction often explicitly or implicitly focusses more on the adaptation of technologies than on the role of social interpretation of technology by end-users. Focusing specifically on how end-users, collectively and over time, respond to new technologies in organisational settings, we performed an extensive review of literature employing elements of structured and hermeneutical approaches. We identify 5 key dimensions employed by authors to conceptualise technology introduction and distinguish 3 major streams of literature using the particular positions that each paper takes along these dimensions. The streams are mainly distinguished by how they conceive the social aspects of the process and how they understand the effects of technology. This finding has implications for appropriate management of the process under each conception

    Liquefaction of Soils in the 1989 Loma Prieta Earthquake

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    The Loma Prieta Earthquake of October 17, 1989 was the most costly single natural disaster in U.S. history, resulting in losses of 7to7 to 9 billion, and claiming 63 lives. These damages were concentrated mainly at a number of distinct sites comprising a relatively small fraction of the affected region, as local site conditions and related geotechnical factors exerted a major influence on damage patterns and loss of life in this catastrophic event. This paper discusses one of these geotechnical factors, the widespread occurrence of soil liquefaction during the earthquake, as well as the associated damages and the resulting lessons learned. Additional significant geotechnical factors which exerted a strong influence on damage patterns during this event, including site-dependent dynamic response and seismically-induced slope instability, are discussed in companion papers in these proceedings

    Global atmospheric budget of acetaldehyde: 3-D model analysis and constraints from in-situ and satellite observations

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    We construct a global atmospheric budget for acetaldehyde using a 3-D model of atmospheric chemistry (GEOS-Chem), and use an ensemble of observations to evaluate present understanding of its sources and sinks. Hydrocarbon oxidation provides the largest acetaldehyde source in the model (128 Tg a<sup>−1</sup>, a factor of 4 greater than the previous estimate), with alkanes, alkenes, and ethanol the main precursors. There is also a minor source from isoprene oxidation. We use an updated chemical mechanism for GEOS-Chem, and photochemical acetaldehyde yields are consistent with the Master Chemical Mechanism. We present a new approach to quantifying the acetaldehyde air-sea flux based on the global distribution of light absorption due to colored dissolved organic matter (CDOM) derived from satellite ocean color observations. The resulting net ocean emission is 57 Tg a<sup>−1</sup>, the second largest global source of acetaldehyde. A key uncertainty is the acetaldehyde turnover time in the ocean mixed layer, with quantitative model evaluation over the ocean complicated by known measurement artifacts in clean air. Simulated concentrations in surface air over the ocean generally agree well with aircraft measurements, though the model tends to overestimate the vertical gradient. PAN:NO<sub>x</sub> ratios are well-simulated in the marine boundary layer, providing some support for the modeled ocean source. We introduce the Model of Emissions of Gases and Aerosols from Nature (MEGANv2.1) for acetaldehyde and ethanol and use it to quantify their net flux from living terrestrial plants. Including emissions from decaying plants the total direct acetaldehyde source from the land biosphere is 23 Tg a<sup>−1</sup>. Other terrestrial acetaldehyde sources include biomass burning (3 Tg a<sup>−1</sup>) and anthropogenic emissions (2 Tg a<sup>−1</sup>). Simulated concentrations in the continental boundary layer are generally unbiased and capture the spatial gradients seen in observations over North America, Europe, and tropical South America. However, the model underestimates acetaldehyde levels in urban outflow, suggesting a missing source in polluted air. Ubiquitous high measured concentrations in the free troposphere are not captured by the model, and based on present understanding are not consistent with concurrent measurements of PAN and NO<sub>x</sub>: we find no compelling evidence for a widespread missing acetaldehyde source in the free troposphere. We estimate the current US source of ethanol and acetaldehyde (primary + secondary) at 1.3 Tg a<sup>−1</sup> and 7.8 Tg a<sup>−1</sup>, approximately 60{%} and 480% of the corresponding increases expected for a national transition from gasoline to ethanol fuel

    Use of Cyclic Simple Shear Testing in Evaluation of the Deformation Potential of Liquefiable Soils

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    In recent years, a significant research effort has been focused on assessing the performance of structures founded on potentially liquefiable materials. While significant progress has been made on predictive tools for cases in which large deformations are likely, the ability to accurately and reliably predict small to moderate lateral deformations (\u3c1m) has proven more elusive. As a result, there is a universal need for high quality, element-level laboratory test data to calibrate and validate constitutive laws and numerical models for predicting the deformation of soil with limited liquefaction potential. To address this increasingly urgent need, a comprehensive cyclic simple shear testing program on liquefiable sands has been undertaken using the UC Berkeley Bi-directional Simple Shear Device. Many of the tests performed have new and innovative aspects that can provide information and insight into the behavior of soils showing limited deformation potential. Descried in this paper are results from a Kα test series, which replicates sloping ground conditions, and a newly developed and innovative “fabric” test series, which examines the influence of previous loading history on soil fabric and behavior
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