427 research outputs found

    De digitale wichelroede en haar gebruikers : interactieve location based services voor cultuur-historische landschapsbeleving

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    Project de Digitale Wichelroede onderzoekt hoe op innovatieve wijze cultuurhistorische kennis beschikbaar gemaakt kan worden via een PDA met GPS en UMTS-transmissie voor de wandelaar of fietser die zijn omgeving fysiek en virtueel wil beleven, en via de Volksmondfunctie op interactieve wijze informatie kan toevoegen. Circa 70% van de deelnemers oordeelt positief over de Digitale Wichelroede. De belangrijkste conclusie is dat een wandel- of fietstocht met de digitale wichelroede een meerwaarde bevat ten opzichte van een “gewone” wandel- of fietstoch

    Regulatory Compliance in Multi-Tier Supplier Networks

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    Over the years, avionics systems have increased in complexity to the point where 1st tier suppliers to an aircraft OEM find it financially beneficial to outsource designs of subsystems to 2nd tier and at times to 3rd tier suppliers. Combined with challenging schedule and budgetary pressures, the environment in which safety-critical systems are being developed introduces new hurdles for regulatory agencies and industry. This new environment of both complex systems and tiered development has raised concerns in the ability of the designers to ensure safety considerations are fully addressed throughout the tier levels. This has also raised questions about the sufficiency of current regulatory guidance to ensure: proper flow down of safety awareness, avionics application understanding at the lower tiers, OEM and 1st tier oversight practices, and capabilities of lower tier suppliers. Therefore, NASA established a research project to address Regulatory Compliance in a Multi-tier Supplier Network. This research was divided into three major study efforts: 1. Describe Modern Multi-tier Avionics Development 2. Identify Current Issues in Achieving Safety and Regulatory Compliance 3. Short-term/Long-term Recommendations Toward Higher Assurance Confidence This report presents our findings of the risks, weaknesses, and our recommendations. It also includes a collection of industry-identified risks, an assessment of guideline weaknesses related to multi-tier development of complex avionics systems, and a postulation of potential modifications to guidelines to close the identified risks and weaknesses

    Social Movements and Institutional Entrepreneurship as Facilitators of Technology Transition: The Case of Free/Open-Source Software

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    We integrate insights from the literature on social movements and institutional entrepreneurship into the strategic niche management (SNM) and multilevel perspective (MLP) frameworks to understand the emergence of Linux, a free/open-source operating system, in a regime dominated by proprietary operating systems such as Unix and Windows NT. Employing a “microhistories” methodology, we document how actors in the free/open-source movement took steps that enabled an alternate technological niche to form, gain momentum and eventually infiltrate the extant regime. Our account delineates the key role that actors play in shaping the identity of a niche, amplifying its presence, and finally mainstreaming it. We observe a heterogenous response by incumbents to the emergent niche and highlight the sustained coexistence of a niche and regime as a distinct form of technological transition. Finally, we demonstrate the significant impact that a niche can have, spanning beyond the targeted regime, and becoming part of the landscape. Our insights highlight how tracing the processes involved in the emergence and development of a niche can provide a prospective and generative understanding of technological transition, thereby contributing to and complementing the extant SNM and MLP literatures

    Tourist activities description. SASTDes WP3.6 Report

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    Mechanisms in Open Innovation: A Review and Synthesis of the Literature

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    A large body of literature explores the role of context, structure, actors, and outcomes of open innovation (OI), yet pays little attention to the mechanisms underlying these relationships. In this review paper, we synthesize the OI literature using a context-mechanism-outcome approach to identify and classify the various mechanisms observed in empirical OI studies. Our findings demonstrate that the OI literature draws on a wide variety of mechanisms originating from the fields of management, sociology, economics, and psychology. The fifteen mechanisms most frequently observed in the literature fall into four categories: governance and policies; environmental dynamics and interactions; knowledge, skills, and capabilities; and learning by doing. Moreover, by examining the levels of analysis of these mechanisms, we observe substantial differences in how these mechanisms operate at the individual, project, firm, network, and society level. Finally, we identify various avenues for future research arising from our synthesis of the literature

    Photovoltaic quantum well infrared photodetectors

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    Quantum well infrared photodetectors (QWIP) are a promising new approach to long-wavelength infrared detector arrays. Both single-well photovoltaic and multiple-well photoconductive devices have been demonstrated. The author discusses noise considerations as they apply to photovoltaic devices, grating coupling of the infrared light into QWIPs, and recently demonstrated electrically tunable detectors. The use of light trapping to enhance the quantum efficiency and reduce cross-talk in an array is addressed

    3,3′,5,5′-Tetra­nitro­biphen­yl

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    The title compound, C12H6N4O8, is a biphenyl system that was synthesized as a building block for a new series of anti­malarial compounds. The aromatic rings are oriented at a dihedral angle of 45.5 (2)°, and inter­molecular short O⋯O contacts form a chain along the b axis. The strength of the inter­actions involved in this chain cause one of the rings to be slightly distorted, with the torsion angle between the nitro groups being 23.4 (2)°, whereas, in the other ring, both nitro systems are parallel, forming an angle of 9.6 (2)° with the plane of the aromatic ring to which they are bound. Furthermore, the three ring C atoms around the ring–ring linkage belong to a plane inclined by 4.5 (1)° in relation to the plane containing the other three C atoms, i.e. (NO2–)C—C—C(NO2). This distortion of the ring causes uncommonly short intermolecular O⋯O [3.038 (2) Å] and O⋯C [3.000 (4) and 3.214 (1) Å] contacts

    Icodextrin Versus Glucose Solutions for the Once-Daily Long Dwell in Peritoneal Dialysis: An Enriched Systematic Review and Meta-analysis of Randomized Controlled Trials

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    Rationale & Objective The efficacy and safety of icodextrin versus glucose-only peritoneal dialysis (PD) regimens is unclear. The aim of this study was to compare once-daily long-dwell icodextrin versus glucose among patients with kidney failure undergoing PD. Study Design Systematic review of randomized controlled trials (RCTs), enriched with unpublished data from investigator-initiated and industry-sponsored studies. Setting & Study Populations Individuals with kidney failure receiving regular PD treatment enrolled in clinical trials of dialysate composition. Selection Criteria for Studies Medline, Embase, CENTRAL, Ichushi Web, 10 Chinese databases, clinical trials registries, conference proceedings, and citation lists from inception to November 2018. Further data were obtained from principal investigators and industry clinical study reports. Data Extraction 2 independent reviewers selected studies and extracted data using a prespecified extraction instrument. Analytic Approach Qualitative synthesis of demographics, measurement scales, and outcomes. Quantitative synthesis with Mantel-Haenszel risk ratios (RRs), Peto odds ratios (ORs), or (standardized) mean differences (MDs). Risk of bias of included studies at the outcome level was assessed using the Cochrane risk-of-bias tool for RCTs. Results 19 RCTs that enrolled 1,693 participants were meta-analyzed. Ultrafiltration was improved with icodextrin (medium-term MD, 208.92 [95% CI, 99.69-318.14] mL/24 h; high certainty of evidence), reflected also by fewer episodes of fluid overload (RR, 0.43 [95% CI, 0.24-0.78]; high certainty). Icodextrin-containing PD probably decreased mortality risk compared to glucose-only PD (Peto OR, 0.49 [95% CI, 0.24-1.00]; moderate certainty). Despite evidence of lower peritoneal glucose absorption with icodextrin-containing PD (medium-term MD, −40.84 [95% CI, −48.09 to −33.59] g/long dwell; high certainty), this did not directly translate to changes in fasting plasma glucose (−0.50 [95% CI, −1.19 to 0.18] mmol/L; low certainty) and hemoglobin A1c levels (−0.14% [95% CI, −0.34% to 0.05%]; high certainty). Safety outcomes and residual kidney function were similar in both groups; health-related quality-of-life and pain scores were inconclusive. Limitations Trial quality was variable. The follow-up period was heterogeneous, with a paucity of assessments over the long term. Mortality results are based on just 32 events and were not corroborated using time-to-event analysis of individual patient data. Conclusions Icodextrin for once-daily long-dwell PD has clinical benefit for some patients, including those not meeting ultrafiltration targets and at risk for fluid overload. Future research into patient-centered outcomes and cost-effectiveness associated with icodextrin is needed
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