272 research outputs found

    New Interchange, I-69 and 106th Street, Fishers, Indiana

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    This first-of-its-kind oval-about interchange was an INDOT project with financial support from both the City of Fishers and Hamilton County, in a combined effort to relieve congestion at the two existing adjacent interchanges of 96th and 116th Streets. We will discuss the extensive traffic analysis completed for the FHWA Interchange Justification Study, modifications in roundabout design, cost savings of two parallel two-lane bridges versus one oddshaped five-lane bridge, and lessons learned in utility coordination

    Towards a Theory of Software Development Expertise

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    Software development includes diverse tasks such as implementing new features, analyzing requirements, and fixing bugs. Being an expert in those tasks requires a certain set of skills, knowledge, and experience. Several studies investigated individual aspects of software development expertise, but what is missing is a comprehensive theory. We present a first conceptual theory of software development expertise that is grounded in data from a mixed-methods survey with 335 software developers and in literature on expertise and expert performance. Our theory currently focuses on programming, but already provides valuable insights for researchers, developers, and employers. The theory describes important properties of software development expertise and which factors foster or hinder its formation, including how developers' performance may decline over time. Moreover, our quantitative results show that developers' expertise self-assessments are context-dependent and that experience is not necessarily related to expertise.Comment: 14 pages, 5 figures, 26th ACM Joint European Software Engineering Conference and Symposium on the Foundations of Software Engineering (ESEC/FSE 2018), ACM, 201

    Electrolysing mud: Membraneless electrolysis of water for hydrogen production using montmorillonite-rich marine mud

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    This paper describes a design for a low-cost membraneless water electrolyser for the production of green hydrogen that used a viscous electrolyte of naturally abundant montmorillonite-rich marine mud in a DEFT (divergent electrode flow through) geometry with stainless steel (304) mesh electrodes. The ratio of smectite to non-swelling clays in the mud was 1:2. The electrolyte was prepared by resuspending the mud in tap-water to remove the salt, and NaOH 1 M added to enhance the ionic conductivity, as measured by both Electrochemical Impedance Spectroscopy (EIS) and by the slope of DC current/voltage curves. Successful separation and collection of the hydrogen and oxygen gas was inferred from the ratio of 2:1 in the volumes of hydrogen and oxygen collected. Both acid and alkali treatments were trialled and it was found that, whereas acid treatment flocculated the mud, adding NaOH increased the dispersion, conductivity and viscosity, and reduced clogging. The conductivity of both the 24% dry mass alkali mud and a control 4% dry mass alkali bentonite suspension increased to that of pure NaOH 1 M when repeatedly electrolysed. Hydrogen and oxygen gas was collected for 10% and 24% dry mass muds. The less viscous 10% dry mass mud showed turbulent liquid-like behaviour which led to gas mixing but the 24% mud showed stable, solid-like flow and reliable gas separation. Three components of the energy efficiency of the electrolysis process are reported and discussed – the voltage efficiency of 42%, a gas collection efficiency of 50% and the auxiliary power efficiency of 60%. The overall energy efficiency due to these three contributing efficiencies, was 13% of the Higher Heating Value of 142 MJ/kg H2 for a current density of 45 mA/cm2. This mud electrolyser may still be considered worth developing for an off-grid, low budget site with a low-power source of renewable energy

    Digital Harmony of Sound and Light

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    Using z14 Fused-Multiply-Add Instructions to Accelerate Elliptic Curve Cryptography

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    Due to growing commercial applications like Blockchain, the performance of large-integer arithmetic is the focus of both academic and industrial research. IBM introduced a new integer fused multiply-add instruction in z14, called VMSL, to accelerate such workloads. Unlike their floating-point counterparts, there are a variety of integer fused multiply-add instruction designs. VMSL multiplies two pairs of radix 2562^{56} inputs, sums the two results together with an additional 128-bit input, and stores the resulting 128-bit value in a vector register. In this paper, we will describe the unique features of VMSL, the ways in which it is inherently more efficient than alternative specifications, in particular by enabling multiple carry strategies. We will then look at the issues we encountered implementing Montgomery Modular Multiplication for Elliptic Curve Cryptography on z14, including radix choice, mixed radices, instruction selection to trade instruction count for latency, and VMSL-specific optimizations for Montgomery-friendly moduli. The best choices resulted in a 20% increase in throughput

    AN ANALYSIS of the 20-year use of a deep Broward County lime-rock pit as a natural advanced wastewater treatment and groundwater recycling facility, with a recommendation that: with the large number of similar lime-rock pits in Southeast Florida, the opportunity for expanding the benefits of such inland wastewater retention should be given serious consideration instead of wastefully discharging the water into the ocean.

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    The benefits of the inland retention of freshwaters in South Florida are indisputable. During periods of prolonged drought, the maintenance of a higher groundwater table, which benefits terrestrial vegetation and retards saltwater intrusion, is clearly preferable to the alternative of discharging up to 400,000 gallons of freshwater per day into the ocean. Therefore, the only objections to the retention of treated sewage effluent in an inland lime-rock pit, with the physical, chemical and biologic characteristics of our pits, would have to do with possible detrimental effects to public health or the environment. The major public health concern involves the possible discharge of human pathogens. This can be prevented by high-level chlorination of well-treated effluent such as that of the Ferncrest Utilities. With the cooperation and help of the Nova University Oceanographic Center, the Florida Agricultural Research and Education Station, the Broward County Environmental Quality Control Board and the landowners, the Tindall Hammock Irrigation and Soil Conservation District and the Ferncrest Utilities respectfully submit that retention of the excellent tertiary-treated Ferncrest Utilities effluent in such a lime-rock pit accomplishes the following: • Provides an inexpensive, safe, practical, alternative, non-structural, natural, and environmentally sound drainage and wastewater pollutant treatment and inactivation facility that uses no energy except sunlight. • Conserves, stores and recycles stormwater and wastewater instead of wasteful discharge into canals or the ocean. • Helps to maintain a higher groundwater elevation, thereby reducing the volume of irrigation water needed for area lawns and shrubbery, and the energy and expense thereof. • Retards the rate of saltwater intrusion into the aquifer. • Enhances the U.S. EPA\u27s goal of fishable, swimmable public waters by complexing and precipitating runoff and wastewater pollutants, thereby keeping them out of the North New River Canal, the New River and the ocean. With the large number of similar lime-rock pits in Southeast Florida, the opportunity for expanding the benefits of such inland wastewater retention should be given serious consideration

    Managing Technical Debt in Software Engineering

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    Sustainable and scalable software systems require careful consideration over the force known as technical debt, i.e., the additional project cost connected to sub-optimal technical decisions. However, the friction that software systems can accumulate is not connected to technical decisions alone, but reflects also organizational, social, ontological and management decisions that refer to the social nature and any connected social debt of software – this nature is yet to be fully elaborated and understood. In a joint industry & academia panel, we refined our understanding of the emerging notion of social debt in pursuit of a crisper definition. We observed that social debt is not only a prime cause for technical debt but is also tightly knit to many of the dimensions that were observed so far concerning technical debt, for example software architectures and their reflection on organizations. Also we observed that social debt reflects and weighs heavily on the human process behind software engineering, since it is caused by circumstances such as cognitive distance, (lack of or too much of) communication, misaligned architectures and organizational structures.The goal for social debt in the next few years of research should be to reach a crisp definition that contains the essential traits of social debt which can be refined into practical operationalizations for use by software engineering professionals in need of knowing more about their organizational structure and the properties/cost trade-off that structure currently reflects.</p

    Modelling and mapping of exceedance of critical loads and critical levels for acidification and eutrophication in the UK 2013-2016. Final report

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    This report covers the work of the original contract (2013-15) and the following one-year extension (2015-16). The overall purpose of this project was to maintain, and where appropriate update, the UK critical loads database, and to provide estimates of critical load and critical level exceedance based on current pollutant deposition or concentrations, and scenarios for the future. The exceedance results were used to inform policy makers on the areas of sensitive habitats and designated sites potentially at risk from air pollution and were updated annually to provide a UK indicator of the impacts of air pollution on ecosystems. The project also supported the UK National Focal Centre (NFC) for critical loads modelling and mapping. The 1-year extension to this contract additionally included the biodiversity modelling required to enable the UK NFC to begin work in preparation for responding to the 2015-17 “Call for Data” under the UNECE Convention on Long-Range Transboundary Air Pollution (CLRTAP)
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