1,203 research outputs found

    Torsional rigidity for regions with a Brownian boundary

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    Let TmT^m be the mm-dimensional unit torus, m∈Nm \in N. The torsional rigidity of an open set Ω⊂Tm\Omega \subset T^m is the integral with respect to Lebesgue measure over all starting points x∈Ωx \in \Omega of the expected lifetime in Ω\Omega of a Brownian motion starting at xx. In this paper we consider Ω=Tm\β[0,t]\Omega = T^m \backslash \beta[0,t], the complement of the path β[0,t]\beta[0,t] of an independent Brownian motion up to time tt. We compute the leading order asymptotic behaviour of the expectation of the torsional rigidity in the limit as t→∞t \to \infty. For m=2m=2 the main contribution comes from the components in T2\β[0,t]T^2 \backslash \beta [0,t] whose inradius is comparable to the largest inradius, while for m=3m=3 most of T3\β[0,t]T^3 \backslash \beta [0,t] contributes. A similar result holds for m≥4m \geq 4 after the Brownian path is replaced by a shrinking Wiener sausage Wr(t)[0,t]W_{r(t)}[0,t] of radius r(t)=o(t−1/(m−2))r(t)=o(t^{-1/(m-2)}), provided the shrinking is slow enough to ensure that the torsional rigidity tends to zero. Asymptotic properties of the capacity of β[0,t]\beta[0,t] in R3R^3 and W1[0,t]W_1[0,t] in RmR^m, m≥4m \geq 4, play a central role throughout the paper. Our results contribute to a better understanding of the geometry of the complement of Brownian motion on TmT^m, which has received a lot of attention in the literature in past years.Comment: 26 pages, 1 figur

    Direct Speech Quote Attribution for Dutch Literature

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    We present a dataset and system for quote attribution in Dutch literature. The system is implemented as a neural module in an existing NLP pipeline for Dutch literature (dutchcoref; van Cranenburgh, 2019). Our contributions are as follows. First, we provide guidelines for Dutch quote attribution and annotate 3,056 quotes in fragments of 42 Dutch literary novels, both contemporary and classic. Second, we present three neural quote attribution classifiers, optimizing for precision, recall, and F1. Third, we perform an evaluation and analysis of quote attribution performance, showing that in particular, quotes with an implicit speaker are challenging, and that such quotes are prevalent in contemporary fiction (57%, compared to 32% for classic novels). On the task of quote attribution, we achieve an improvement of 8.0% F1 points on contemporary fiction and 1.9% F1 points on classic novels. Code, data, and models are available at https://github.com/anonymized/repository

    An ISFET-based anion sensor for the potentiometric detection of organic acids in liquid chromatography

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    An ion-selective field effect transistor (ISFET) was applied as a potentiometric detector in liquid chromatography (LC) for the determination of organic acids. The ISFET was prepared by coating the gate insulator of the encapsulated transistor with a poly(vinyl chloride) (PVC) matrix membrane containing methyltridodecylammoniumchloride, which enables the detection of organic anions. The ISFET was tested for its applicability as detector for carboxylic acids in ion-exchange and reversed-phase chromatography. Its analytical characteristics were compared to those of a coated-wire electrode (CWE) and of a conventional type of ion-selective electrode (ISE)

    The efficacy of oral corticoids in treating complex regional pain syndrome:A retrospective cohort study

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    Objectives: There is growing evidence supporting the role of inflammatory mechanisms in complex regional pain syndrome (CRPS). Corticoids, as most effective anti-inflammatory drugs, are widely used in treating inflammation. The aim of this study was to retrospectively assess the efficacy of oral corticoid treatment in CRPS patients. Methods: Patients treated at the center of pain medicine in the Erasmus University Medical Centre between January 2015 and January 2020 were approached to partake in this study. Medical records were screened for age, gender, medical history, duration of CRPS, and CRPS severity score. Also, treatment effect, dose and duration, pain scores (NRS), and side effects were extracted from medical records. In addition, global perceived effect was completed in patients treated with corticoids. Results: Between January 2015 and January 2020, twenty-nine CRPS patients received corticoids and met the inclusion criteria. One extreme outlier was excluded and treatment effect was unknown for one patient. Average daily dose was 28.9 mg (range 10–30 mg) and the mean treatment duration was 10.5 days (7–21 days). Fourteen patients (51.9%) responded positively to treatment and thirteen (48.1%) did not respond. Side effects were reported in five patients (17.9%). Conclusions: Corticoid treatment was effective in more than half of the patients. With only mild side effects reported the treatment also appears to be relatively safe. Further research is needed to investigate the efficacy of corticoids in treating (early) CRPS, preferably in an intervention study.</p

    A Hybrid Rule-Based and Neural Coreference Resolution System with an Evaluation on Dutch Literature

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    We introduce a modular, hybrid coreference resolution system that extends a rule-based baseline with three neural classifiers for the subtasks mention detection, mention attributes (gender, animacy, number), and pronoun resolution. The classifiers substantially increase coreference performance in our experiments with Dutch literature across all metrics on the development set: mention detection, LEA, CoNLL, and especially pronoun accuracy. However, on the test set, the best results are obtained with rule-based pronoun resolution. This inconsistent result highlights that the rule-based system is still a strong baseline, and more work is needed to improve pronoun resolution robustly for this dataset. While end-to-end neural systems require no feature engineering and achieve excellent performance in standard benchmarks with large training sets, our simple hybrid system scales well to long document coreference (&gt;10k words) and attains superior results in our experiments on literature
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