170,040 research outputs found

    Identification of Evolving Rule-based Models.

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    An approach to identification of evolving fuzzy rule-based (eR) models is proposed. eR models implement a method for the noniterative update of both the rule-base structure and parameters by incremental unsupervised learning. The rule-base evolves by adding more informative rules than those that previously formed the model. In addition, existing rules can be replaced with new rules based on ranking using the informative potential of the data. In this way, the rule-base structure is inherited and updated when new informative data become available, rather than being completely retrained. The adaptive nature of these evolving rule-based models, in combination with the highly transparent and compact form of fuzzy rules, makes them a promising candidate for modeling and control of complex processes, competitive to neural networks. The approach has been tested on a benchmark problem and on an air-conditioning component modeling application using data from an installation serving a real building. The results illustrate the viability and efficiency of the approach. (c) IEEE Transactions on Fuzzy System

    Carbon load in aquatic ecosystems affects the diversity and biomass of water biofilm consortia and the persistence of the pathogen Campylobacter jejuni within them

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    The influence of carbon load on autochthonous water microflora population distribution and diversity, and on the persistence of Campylobacter jejuni, was examined with a two-stage aquatic biofilm model. Serine was chosen since it is a carbon source utilised by C. jejuni and concentrations were chosen to reflect upper limits of amino acid load reported in surface water. The total viable count of the autochthonous biofilm microflora increased with increasing serine concentration (10-fold and 20-fold with 5nM and 5μM serine, respectively), as did the counts of the microflora in the planktonic phase. Differences in biofilm species distribution as determined by culture were small with changes in temperature or the addition of serine; but was markedly affected by serine as determined by light microscopy, becoming more luxuriant and dominated by long filamentous cells. The addition of serine to the water significantly and progressively reduced the persistence of C. jejuni, which decreased by 25% and 50% with serine concentrations of 5 nM and 5 μM respectively. We have demonstrated that carbon load affects the species diversity and density of both the planktonic and biofilm phase of aquatic autochthonous microflora. Although the survival of C. jejuni in water in a culturable form was sufficient for this to be an important vehicle for its transmission, carbon load significantly influenced survival an increase in serine concentration significantly reduced survival

    Coaggregation amongst aquatic biofilm bacteria

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    Aquatic autochthonous flora isolated directly from a water biofilm model was tested for its capacity to take part in coaggregation. Two assay methods were compared and a visual semi-quantitative method was found to be the most consistent and easy to use. All isolates demonstrated coaggregation with at least one other isolate to some extent, giving rise to visible flocs. One isolate, identified as Micrococcus luteus, was found to coaggregate with all of the other isolates to different degrees, highlighting a possible role as a bridging organism in the biofilm consortium. The addition of certain simple sugars reversed coaggregation between particular isolates suggesting that lectin-like adhesins were operating between these members of the aquatic autochthonous flora by a mechanism similar to that reported to occur between dental plaque bacteria. The time taken for coaggregation to begin varied considerably between different pairs of isolates (1-16 h), suggesting that this may play a role in determining the successional order of isolates during biofilm development.</p

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    Mitomycin C in highly myopic eyes - Author reply

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    Ophthalmology. 2005 Feb;112(2):208-18; discussion 219. Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes. Gambato C, Ghirlando A, Moretto E, Busato F, Midena E. SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy. Abstract PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes. DESIGN: Prospective, double-masked, randomized clinical trial. PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia. METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months). MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH. RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively). CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK. Comment in Ophthalmology. 2006 Feb;113(2):357; author reply 357-8

    Dispelling the Myths Behind First-author Citation Counts

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    We conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more sophisticated methods

    Evolving rule-based models: a tool for intelligent adaptation

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    An online approach for rule-base evolution by recursive adaptation of rule structure and parameters is described . An integral part of the procedure is to maximise the model transparency by simplifying the fuzzy linguistic descriptions of the input variables. The rule base evolves over time, utilising direct calculation approaches and hence minimising the reliance on the use of computationally expensive techniques, such as genetic algorithms. An online version of subtractive clustering recently introduced by the authors (P.P. Angelov and R.A. Buswell) is used for determination of the antecedent part of the fuzzy rules. Recursive least squares estimation is employed to determine the parameters of the consequent part of each rule. The use of these efficient non-iterative techniques is the key to the low computational demands of the algorithm. The application of similarity measures improves the interpretability and compactness of the resulting eR model, with no significant detriment to the model precision. A time series prediction problem on data from a real indoor climate control (ICC) system has been considered to test and validate the proposed model simplification method (c) IEEE Pres

    Online shopping and potential changes to the low value threshold: costs and benefits for government, consumers and retailers

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    Imposing the GST on different types of imports has been a contentious topic for some time. Different parts of Australian society stand to benefit or lose significantly depending on how, or whether, the system is changed. This paper outlines the regulatory framework, including the relationship between online shopping and the low value threshold. Executive summary Australians spent 15.7billionintheyeartoAugust2014buyingonlinefrombothinternationalandAustralianretailers.OnlineshoppingbyAustralianshasincreasedovertime,andislikelytocontinuedoingso.AsignificantportionofAustralianpurchasesonlinearefromAustralianretailers.Thelowvaluethreshold(LVT)exemptseligibleimportsbelow15.7 billion in the year to August 2014 buying online from both international and Australian retailers. Online shopping by Australians has increased over time, and is likely to continue doing so. A significant portion of Australian purchases online are from Australian retailers. The low value threshold (LVT) exempts eligible imports below 1,000 in value from a number of Commonwealth legal requirements. One of these exemptions is that goods below 1,000invaluearegenerallynotsubjecttothegoodsandservicestax(GST).ThisLVTexemptionenablesinternationalretailerstoselltoAustralianconsumerswithoutchargingGST.ThiscancontributetoapricedifferentialbetweengoodssoldbyAustralianretailersandbyinternationalretailers,whichcanbeasignificantfactorinconsumerchoices.TotheextentthattheLVTinfluencesconsumerchoices(andthusreducestheimpactofunderlyingmarketfactors),itdistortscompetitionbetweenAustralianandinternationalretailers.TheLVTisnotindexed,andhasremainedat1,000 in value are generally not subject to the goods and services tax (GST). This LVT exemption enables international retailers to sell to Australian consumers without charging GST. This can contribute to a price differential between goods sold by Australian retailers and by international retailers, which can be a significant factor in consumer choices. To the extent that the LVT influences consumer choices (and thus reduces the impact of underlying market factors), it distorts competition between Australian and international retailers. The LVT is not indexed, and has remained at 1,000 since 1985, losing value in real terms. If indexed, the threshold would be significantly higher. The majority of imported items below the LVT are quite low in value (many are less than 100).TocollectGSTonitemsbelowtheLVTwouldrequireadditionalprocessing.Thecostofthisadditionalprocessingdependsonthelevelatwhichanewthresholdwouldapplywhetheratzero,orsomevaluebetweenzeroand100). To collect GST on items below the LVT would require additional processing. The cost of this additional processing depends on the level at which a new threshold would apply—whether at zero, or some value between zero and 1,000. Depending on the level at which a new threshold is applied, the cost of the additional processing required might be greater than the revenue raised, resulting in a net cost. This would reduce the GST revenue flowing to state and territory governments. A number of previous reviews have examined the issue: –&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; The Productivity Commission recommended in 2011 that the LVT not be lowered unless it was cost-effective to do so, and that further work be undertaken. –&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; The Low Value Parcel Processing Taskforce undertook more detailed research in 2012. They recommended further analysis, and that any goods which were subject to a lower GST threshold also be subject to border agency fees and charges. A number of countries apply fees and charges to incoming international mail items. These fees and charges cover the cost of processing, enabling governments to collect tax revenue on low-value items. Previous analysis suggests that removing the LVT (charging GST on all items) would have a very marginal negative impact on the economy overall, but would benefit the retail sector. The extent to which state and territory governments, household or retail sectors benefit or lose from changes would depend on the level at which the threshold is set, and whether fees and charges are used to cover the cost of processing

    A Multi-Language Comparison of Influences on Author Verification using Character N-Grams

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    We create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc

    A 0.12mm<sup>2</sup> Wien-Bridge Temperature Sensor with 0.1°C (3σ) Inaccuracy from -40°C to 180°C

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    Resistor-based temperature sensors can achieve much higher resolution and energy efficiency than conventional BJT-based sensors [1], but they typically occupy more area (&gt; 0.25 mm 2 ) and have lower operating temperatures (le 125 {circ} {C}) [2]-[4]. This work describes a 0.12mm 2 resistor-based sensor that uses a Wien-bridge (WB) filter to achieve 0.1 {circ} {C} (3 sigma) inaccuracy from - 40 {circ} {C} to 180 {circ} {C}. Compared to a state-of-the-art WB sensor [4], it occupies 6 × less area and achieves comparable relative accuracy over a 76% wider operating range. Session 10.3 Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
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