1,031 research outputs found

    Calibration and characterisation with a new laser-based magnetostriction measurement system

    Get PDF
    A laser-based magnet measurement system has been developed to measure the magnetostrictive strain of large cylindrical samples. The measurement system incorporates a solenoid capable of generating a maximum magnetic field intensity of 3000 Oe and a laser displacement sensor. For calibration and evaluation purposes, the positive magnetostrictions of two different types of giant magnetostrictive Tb–Dy–Fe-based materials were accessed with this system. A magnetostrictive strain of 622 ppm was obtained at 3000 Oe for TbxDy1-xFe2-y, compared with 725 ppm for Tb0.27Dy0.73Fe2. A rod of sintered cobalt ferrite was also measured. This exhibited negative magnetostriction, with a maximum contraction of 260 ppm at 3000 Oe

    Comparative Analysis of Statistical Model Checking Tools

    Get PDF
    Statistical model checking is a powerful and flexible approach for formal verification of computational models like P systems, which can have very large search spaces. Various statistical model checking tools have been developed, but choosing between them and using the most appropriate one requires a significant degree of experience, not only because different tools have different modelling and property specification languages, but also because they may be designed to support only a certain subset of property types. Furthermore, their performance can vary depending on the property types and membrane systems being verified. In this paper we evaluate the performance of various common statistical model checkers against a pool of biological models. Our aim is to help users select the most suitable SMC tools from among the available options, by comparing their modelling and property specification languages, capabilities and performances

    Environmental orientation of government procurement in Singapore

    Get PDF
    This study focuses on sustainable procurement in the public organisations in Singapore using structural equation modelling (SEM). A total of 570 questionnaires were distributed, 370 were returned and 295 were used for analysis representing 52% response rate. Results of the SEM showed that out of ten hypotheses constructed, eight hypotheses are supported. The results of the SEM showed that Waste Management (WM), Organisational Systems and Processes & Policies (OSPP) and Organisational Values (OVALUES) are determinants of environmentally-oriented government procurement in Singapore. The determinant - WM consists of reverse logistics, recycling and packaging. It influences environmentally-oriented procurement practices in public organisations. Public organisations in Singapore are focussing on the benefits of reverse logistics, recycling and packaging as measures of care for the environment. The determinant - OVALUES consists of entrepreneurship, commitment, learning capability and innovation. These could shape and strengthen the culture of public organisations towards environmentally-oriented procurement practices vis-à-vis the value for money and cost efficiency, which has been the guiding principle of public procurement in the long run. This determinant is expected to have an impact on the marketplace where more innovative environmentally-oriented products could be manufactured. The determinant - OSPP which encompasses the established framework of ISO 14001, eco-labelling, product design and life cycle analysis, could further strengthen sustainable procurement practices in public organisations. The adoption of an established framework of systems, processes and policies would guide government officers in making decisions to procure sustainable products. This determinant would also facilitate their learning capability and shorten the learning curve. This study contributes valuable insight into the determinants of environmentally-oriented procurement in public organisations in Singapore. Both managers and researchers would find it useful to know that WM, OSPP OVALUES could provide a basis in developing a managerial framework to procure environmentally-oriented products in public organisations

    Nonparametric statistical process control : an overview and some results

    Get PDF
    An overview of the literature on some nonparametric or distribution-free quality control procedures is presented for univariate data. A nonparametric control chart is defined along with some general motivations and formulations. Various advantages of these charts are highlighted while some disadvantages of the more traditional, distribution-based. control charts are pointed out. Specific observations are made in the course of the review of articles and constructive criticism is offered. so that opportunities for further research can be identified. Connections to some areas of active research are made. such as sequential analysis, that are of relevance to process control. It is hoped that this article would lead to a wider acceptance of distribution-free control charts among the practitioners and would serve as an impetus to future research and development in this area

    Brain inspired computing networks for smart building monitoring

    Get PDF
    The intelligent sensor systems capable of measuring a wide range of building conditions remotely, and in a real-time manner can reveal useful information on the overall quality of services offered in the maintenance and reliability of building space

    Brain inspired computing networks for smart building monitoring

    Get PDF
    The intelligent sensor systems capable of measuring a wide range of building conditions remotely, and in a real-time manner can reveal useful information on the overall quality of services offered in the maintenance and reliability of building space

    Fouling and boring organisms that deteriorate various European and tropical woods at Turkish seas

    Get PDF
    This study aims to investigate the diversity of fouling and boring organisms damaging wood material at Turkish coasts. Trials were carried out at six harbour sites throughout the seas surrounding Turkey.Various Euopean and tropical wood samples were hanged down at a depth of six meters in the sea for a period of one year. Identification of the organisms obtained from wood panels revealed the presence offive wood borer and 26 fouling species. skenderun harbour had the highest boring organism diversity (five species) and it was followed by Trabzon and Finike harbours (three species) and Bandirma, Eregli and Alacati harbours (two species). The two molluscan boring species, Teredo navalis and Lyrodus pedicellatus were observed at all harbour sites, but Nototeredo norvegica was at Trabzon and skenderun harbours only. Bankia carinata was obtained only at skenderun harbour and the crustacean wood borer Limnoria tripunctata was found at Finike and skenderun harbours. All native tree species, except for the olive, were significantly damaged by fouling and boring organisms

    The left anterior right temporal (LART) placement for electroconvulsive therapy: A computational modelling study

    Full text link
    Electrode placement in electroconvulsive therapy (ECT) has a major impact on treatment efficacy and cognitive side effects. Left Anterior Right Temporal (LART) is a lesser utilised bilateral montage which may produce more optimal clinical outcomes relative to standard bitemporal ECT. In this study we used computational modelling to explore how stimulation effects from LART and two novel variants (LART – F3 and LART – Frontal) compared to the more common bilateral placements of bitemporal and bifrontal ECT. High resolution finite element human head models were generated from MRI scans of three subjects with Major Depressive Disorder. Differences in regional stimulation were examined through parametric tests for regions of interest and subtraction maps. Compared to bitemporal ECT, LART – Original resulted in significantly greater stimulation of the left cingulate gyrus (hypothesised to be associated with treatment efficacy), and relatively reduced stimulation of the bilateral hippocampi (potentially associated with cognitive side effects). No additional clinical benefit was suggested with the novel LART placements compared to the original LART. The original LART placement is a promising montage for further clinical investigation

    HT-FED2004-56824 AEROACOUSTIC CHARACTERISTICS OF EFFICIENT AUTOMOTIVE ENGINE COOLING FAN SYSTEMS

    Get PDF
    ABSTRACT Recent studies on automotive engine cooling fan systems carried out in partnership between LEMFI and Valeo have led to the definition of a range of efficient stator designs. It was shown that an adequate rotor-stator coupling could yield significant efficiency gains over the whole range of Valeo fans with diameters ranging from 280 mm to 460 mm. Efficiency gains ranging from 12 percentage points for the 350 mm fan diameter to 2 points for the 460 mm were estimated by using a simplified radial equilibrium design (SRE). These predictions have been verified experimentally by recent designs for various fan system diameters. The present study then describes a newly developed aeroacoustic test facility dedicated to automotive fan systems. The influence of the rotor-stator coupling is then shown by comparing the rotor alone and rotor-stator configurations, not only on the overall performances and velocity fields at the system outlet measured by a 5-hole probe, but also on the noise generated by the fan systems for various flow conditions. At the nominal flow rate, the efficient stators are shown to bring little or no extra noise if the number of stators and the rotor-distance are carefully chosen. At other flow rates, additional noise might be expected
    corecore