84 research outputs found

    Checking sequence construction using adaptive and preset distinguishing sequences

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    Methods for testing from finite state machine-based specifications often require the existence of a preset distinguishing sequence for constructing checking sequences. It has been shown that an adaptive distinguishing sequence is sufficient for these methods. This result is significant because adaptive distinguishing sequences are strictly more common and up to exponentially shorter than preset ones. However, there has been no study on the actual effect of using adaptive distinguishing sequences on the length of checking sequences. This paper describes experiments that show that checking sequences constructed using adaptive distinguishing sequences are almost consistently shorter than those based on preset distinguishing sequences. This is investigated for three different checking sequence generation methods and the results obtained from an extensive experimental study are given

    A Test of Independence in Two-Way Contingency Tables Based on Maximal Correlation

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    Cataloged from PDF version of article.Maximal correlation has several desirable properties as a measure of dependence, including the fact that it vanishes if and only if the variables are independent. Except for a few special cases, it is hard to evaluate maximal correlation explicitly. We focus on two-dimensional contingency tables and discuss a procedure for estimating maximal correlation, which we use for constructing a test of independence. We compare the maximal correlation test with other tests of independence by Monte Carlo simulations. When the underlying continuous variables are dependent but uncorrelated, we point out some cases for which the new test is more powerful

    The stability and dispersion of carbon nanotube-polymer solutions: A molecular dynamics study

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    Carbon nanotubes have been explored to increase the mechanical properties and electrical conductivity of polymeric fibers through compounding with polymer to be extruded into fibers. However, this route creates major challenges because carbon nanotubes have strong cohesion and tend to aggregate and precipitate due to their poor interfacial interaction with polymers. In this study, classical molecular dynamics simulations are used to predict and characterize carbon nanotubes-polymer interface mechanism in two different polymer matrices: polyvinyl butyral and polystyrene-co-glycidyl methacrylate. The dominated interface mechanisms are discovered to shed light on carbon nanotubes dispersion in solvent based systems and to explore the prerequisites for stabilized nanofluids. Our results showed that π-stacking interactions between aromatic groups and graphene surfaces of carbon nanotubes as in polystyrene-co-glycidyl methacrylate systems, play an important role in dispersion of carbon nanotubes, whereas slight repulsions between carbon nanotubes and polyvinyl butyral chains lead to large morphological differences and carbon nanotubes bundles in many chain systems. Altogether, the results indicated that polymers with structures having strong interactions with the surfaces of carbon nanotubes through π–π interactions are more effective in dispersing carbon nanotubes and caused stabilized solutions in wet fiber processing

    Nanofiber-enhanced lightweight composite textiles for acoustic applications

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    This paper proposes lightweight textile acoustic structure, wherein electrospun polyacrylonitrile-based nanofibers enhance sound absorption properties with no weight and thickness penalty. Polyacrylonitrile nanofibers with diameter of 110 ± 7 nm were electrospun on spacer-knitted fabrics by varying deposition amount and surface coating arrangement. Proposed novel approach eliminated additional processing steps such as handling and post-lamination and provided easy scalability of nanofibers at macro-scale. The results showed that the sound absorption of nano-enhanced specimens was improved drastically when deposited amount of nanofibers or its effective surface area increased. Sound propagation paths in different configurations were interpreted from sound absorption and air permeability measurements. The sound absorption coefficient values up to 0.7 are achieved in the low and medium frequency ranges with no weight and thickness penalty by tuning deposition amount and surface coating arrangement

    Using synchronizing heuristics to construct homing sequences

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    Computing a shortest synchronizing sequence of an automaton is an NP-Hard problem. There are well-known heuristics to find short synchronizing sequences. Finding a shortest homing sequence is also an NP-Hard problem. Unlike existing heuristics to find synchronizing sequences, homing heuristics are not widely studied. In this paper, we discover a relation between synchronizing and homing sequences by creating an automaton called homing automaton. By applying synchronizing heuristics on this automaton we get short homing sequences. Furthermore, we adapt some of the synchronizing heuristics to construct homing sequences

    Facilitation of oral sensitivity by electrical stimulation of the faucial pillars

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    Dysphagia is common in neurological disease. However, our understanding of swallowing and its central nervous control is limited. Sensory information plays a vital role in the initiation of the swallowing reflex and is often reduced in stroke patients. We hypothesized that the sensitivity threshold of the anterior faucial pillar could be facilitated by either electrical stimulation (ES) or taste and smell information. The sensitivity threshold was measured by ES in the anterior faucial pillar region. The measurement was repeated 5 min after baseline. Thirty minutes after baseline, the participants underwent a test for taste and smell. Immediately after the test, the ES was repeated. Thirty healthy volunteers with a mean age of 275.1 participated in the trial. Mean sensitivity threshold at baseline was 1.9 +/- 0.59 mA. The values 5 min after baseline (1.74 +/- 0.56 mA, p=0.027) and 30 min after baseline (1.67 +/- 0.58 mA, p=0.011) were significantly lower compared to the baseline, but there was no difference between the latter (p=0.321). After 5 min, a potentially facilitating effect was found on oral sensitivity by ES of the faucial pillar area. Thirty minutes later, this effect was still present. Trial registration Clinicaltrials.gov, NCT03240965. Registered 7th August 2017-https://clinicaltrials.gov/ct2/show/NCT03240965

    Graphene-based soft wearable antennas

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    Electronic textiles (e-textiles) are about to face tremendous environmental and resource challenges due to the complexity of sorting, the risk to supplies and metal contamination in textile recycling streams. This is because e-textiles are heavily based on the integration of valuable metals, including gold, silver and copper. In the context of exploring sustainable materials in e-textiles, we tested the boundaries of chemical vapour deposition (CVD) grown multi-layer (ML) graphene in wearable communication applications, in which metal assemblies are leading the way in wearable communication. This study attempts to create a soft, textile-based communication interface that does not disrupt tactile comfort and conformity by introducing ML graphene sheets. The antenna design proposed is based on a multidisciplinary approach that merges electromagnetic engineering and material science and integrates graphene, a long-lasting alternative to metal components. The designed antenna covers a wide bandwidth ranging from 3 GHz to 9 GHz, which is a promising solution for a high data rate and efficient communication link. We also described the effects of bending and proximity to the human body on the antenna's overall performance. Overall, the results suggested that graphene-based soft antennas are a viable solution for a fully integrated textile-based communication interface that can replace the current rigid, restrictive and toxic approaches, leading to a future where eco-friendliness and sustainability is the only way forward

    Graphene-enabled adaptive infrared textiles

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    Interactive clothing requires sensing and display functionalities to be embedded on textiles. Despite the significant progress of electronic textiles, the integration of optoelectronic materials on fabrics remains as an outstanding challenge. In this Letter, using the electro-optical tunability of graphene, we report adaptive optical textiles with electrically controlled reflectivity and emissivity covering the infrared and near-infrared wavelengths. We achieve electro-optical modulation by reversible intercalation of ions into graphene layers laminated on fabrics. We demonstrate a new class of infrared textile devices including display, yarn, and stretchable devices using natural and synthetic textiles. To show the promise of our approach, we fabricated an active device directly onto a t-shirt, which enables long-wavelength infrared communication via modulation of the thermal radiation from the human body. The results presented here provide complementary technologies which could leverage the ubiquitous use of functional textiles

    A review exploring the overarching burden of Zika virus with emphasis on epidemiological case studies from Brazil

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    This paper explores the main factors for mosquito-borne transmission of the Zika virus by focusing on environmental, anthropogenic, and social risks. A literature review was conducted bringing together related information from this genre of research from peer-reviewed publications. It was observed that environmental conditions, especially precipitation, humidity, and temperature, played a role in the transmission. Furthermore, anthropogenic factors including sanitation, urbanization, and environmental pollution promote the transmission by affecting the mosquito density. In addition, socioeconomic factors such as poverty as well as social inequality and low-quality housing have also an impact since these are social factors that limit access to certain facilities or infrastructure which, in turn, promote transmission when absent (e.g., piped water and screened windows). Finally, the paper presents short-, mid-, and long-term preventative solutions together with future perspectives. This is the first review exploring the effects of anthropogenic aspects on Zika transmission with a special emphasis in Brazil

    Glycemic control and long-acting insulin analog utilization in patients with type 2 diabetes

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    Introduction: The objective was to compare glycemic control, insulin utilization, and body weight in patients with type 2 diabetes (T2D) initiated on insulin detemir (IDet) or insulin glargine (IGlar) in a real-life setting in the Netherlands. Methods: Insulin-naïve patients with T2D, starting treatment with IDet or IGlar between January 1, 2004 and June 30, 2008, were selected from the PHARMO data network. Glycemic control (hemoglobin A1c [HbA1c]), target rates (HbA1c <7%), daily insulin dose, and weight gain were analyzed comparing IDet and IGlar for patients with available HbA1c levels both at baseline and at 1-year follow-up. Analysis of all eligible patients (AEP) and a subgroup of patients without treatment changes (WOTC) in the follow-up period were adjusted for patient characteristics, propensity scores, and baseline HbA1c. Results: A total of 127 IDet users and 292 IGlar users were included in the WOTC analyses. The mean HbA1c dropped from 8.4%-8.6% at baseline to 7.4% after 1 year. Patients at HbA1c goal increased from 9% at baseline to 32% for IDet and 11% to 35% for IGlar, which was not significantly different (OR 0.75, 95% CI 0.46, 1.24). Weight gain (n=90) was less among IDet users (+0.4kg) than among IGlar users (+1.1kg), albeit not significant. The AEP analysis (252 IDet
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