8,491 research outputs found

    EEG signals analysis using multiscale entropy for depth of anesthesia monitoring during surgery through artificial neural networks

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    In order to build a reliable index to monitor the depth of anesthesia (DOA), many algorithms have been proposed in recent years, one of which is sample entropy (SampEn), a commonly used and important tool to measure the regularity of data series. However, SampEn only estimates the complexity of signals on one time scale. In this study, a new approach is introduced using multiscale entropy (MSE) considering the structure information over different time scales. The entropy values over different time scales calculated through MSE are applied as the input data to train an artificial neural network (ANN) model using bispectral index (BIS) or expert assessment of conscious level (EACL) as the target. To test the performance of the new index's sensitivity to artifacts, we compared the results before and after filtration by multivariate empirical mode decomposition (MEMD). The new approach via ANN is utilized in real EEG signals collected from 26 patients before and after filtering by MEMD, respectively; the results show that is a higher correlation between index from the proposed approach and the gold standard compared with SampEn. Moreover, the proposed approach is more structurally robust to noise and artifacts which indicates that it can be used for monitoring the DOA more accurately.This research was financially supported by the Center for Dynamical Biomarkers and Translational Medicine, National Central University, Taiwan, which is sponsored by Ministry of Science and Technology (Grant no. MOST103-2911-I-008-001). Also, it was supported by National Chung-Shan Institute of Science & Technology in Taiwan (Grant nos. CSIST-095-V301 and CSIST-095-V302) and National Natural Science Foundation of China (Grant no. 51475342)

    Cramér-Rao Bound Optimization for Joint Radar-Communication Beamforming

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    In this paper, we propose multi-input multi-output (MIMO) beamforming designs towards joint radar sensing and multi-user communications. We employ the Cramr-Rao bound (CRB) as a performance metric of target estimation, under both point and extended target scenarios. We then propose minimizing the CRB of radar sensing while guaranteeing a pre-defined level of signal-to-interference-plus-noise ratio (SINR) for each communication user. For the single-user scenario, we derive a closed form for the optimal solution for both cases of point and extended targets. For the multi-user scenario, we show that both problems can be relaxed into semidefinite programming by using the semidefinite relaxation approach, and prove that the global optimum can always be obtained. Finally, we demonstrate numerically that the globally optimal solutions are reachable via the proposed methods, which provide significant gains in target estimation performance over state-of-the-art benchmarks

    Characterization of soluble microbial products as precursors of disinfection byproducts in drinking water supply

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    Water pollution by wastewater discharge can cause the problem of disinfection byproducts (DBPs) in drinking water supply. In this study, DBP formation characteristics of soluble microbial products (SMPs) as the main products of wastewater organic biodegradation were investigated. The results show that SMPs can act as DBP precursors in simulated wastewater biodegradation process. Under the experimental conditions, stabilized SMPs had DBPFP (DBP formation potential) yield of around 5.6 mumol mmol(-1)-DOC (dissolved organic carbon) and DBP speciation profile different from that of the conventional precursor, natural organic matter (NOM). SMPs contained polysaccharides, proteins, and humic-like substances, and the latter two groups can act as reactive DBP precursors. SMP fraction with molecular weight of <1 kDa accounted for 85% of the organic carbon and 65% of the DBP formation. As small SMP molecules are more difficult to remove by conventional water treatment processes, more efforts are needed to control wastewater-derived DBP problem in water resource management.postprin

    Modeling of cable for measurements of small monopole antennas

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    Coaxial cable is often used for measurements of antennas inside anechoic chambers. In the measurement of a monopole antenna with a small ground-plane, the finite-sized ground causes the current to flow back from the radiator to the outer surface of the coaxial cable. This results in secondary radiation which introduces errors to the measured radiation pattern. To reduce the unwanted secondary radiation, the coaxial cable can be covered with EMI suppressant tubing materials. However, this introduces errors to the measured efficiency. In this paper, the models of the coaxial cable with and without suppressant tubing are developed and used for computer simulation. The cable effects on the measured results of a small monopole ultrawide band (UWB) antenna are studied by using the antenna measurement equipment Satimo StarLab and the EM simulation tool CST. The results show great agreements between the simulated and measured results. © 2011 IEEE.published_or_final_versio

    A genetic polymorphism and its genetic effects on goat myogenin gene in intron 1

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    Single nucleotide polymorphisms (SNPs) of the myogenin (MyoG) gene were tested using primer induced restriction fragment length polymorphism assay-polymerase chain reaction (PIRA-PCR) from Bore goat and its upgrading offspring to Tangshan diary goat (including F1, F2 and F3). The effects of the myogenin gene on the birth weight, 1-month body weight and the weaning weight were also analyzed. On the basis of the DNA sequence of the goat myogenin gene (FJ607135), primers were designed to amplify myogenin gene. The result showed that one polymorphism (transition of g.558C&gt;T) was found in intron 1 of goat myogenin gene, in which two alleles (A and B) and three genotypes (AA, AB and BB) were examined. The distributions of three genotypes were basically identical in four goat populations, and allele A was the dominant gene. The effect of the myogenin genotypes on the birth weight, 1-month body weight and the weaning weight were all not significant (P &gt; 0.05) due to the small number of BB gaots; however, the values of AA genotype goats and AB genotype goats were obviously higher than those of BB genotype goats for three growth traits, in the order of AA &gt; AB &gt; BB. These results suggest that the myogenin genotype has some effects on partial growth traits of goat, and selecting the individuals with A allele could be favorable to the birth weight, 1-month body weight and the weaning weight.Key words: goats, myogenin gene, primer induced restriction fragment length polymorphism assay-polymerase chain reaction (PIRA-PCR), genetic polymorphisms, genetic effects

    InN Island shape and its dependence on growth condition of molecular-beam epitaxy

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    The three-dimensional (3D) island shapes of the InN and its dependence on growth conditions of molecular-beam epitaxy (MBE) were analyzed. The islands were dislocated and the strain in an island depended on its size. The pillar-shaped islands with low aspect ratios represented the equilibrium shape, and the pyrimidal islands with higher aspect ratios were limited by kinetics during MBE growth. The decreasing trend of island aspect ratio with respect to island size was attributed to gradual relaxation of residual strain in dislocated islands.published_or_final_versio

    Analysis of investigation of undergraduate nurse's critical thinking

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    2003-2004 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Performance improvements of a split-off band infra-red detector using a graded barrier

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    Uncooled split-off band infrared detectors have been demonstrated with an operational device response in the 3–5 μm range. We have shown that it is possible to enhance this device response through reducing the recapture rate by replacing one of the commonly used flat barriers in the device with a graded barrier, which was grown using a “digital alloying” approach. Responsivity of approximately 80 μA/W (D* = 1.4 × 108 Jones) were observed at 78 K under a 1 V applied bias, with a peak response at 2.8 μm. This is an improvement by a factor of ∼25 times compared to an equivalent device with a flat barrier. This enhancement is due to improved carrier transport resulting from the superlattice structure, and a low recapture rate enabled by a reduced distance to the image force potential peak in the graded barrier. The device performance can be further improved by growing a structure with repeats of the single emitter layer reported here

    Scaling of three-dimensional InN islands grown on GaN(0001) by molecular-beam epitaxy

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    The scaling property of three-dimensional InN islands nucleated on GaN(0001) surface during molecular-beam epitaxy (MBE) is investigated. Due to the large lattice mismatch between InN and GaN (∼10%), the islands formed from the Stranski-Krastanow growth mode are dislocated. Despite the variations in (residual) strain and the shape, both the island size and pair separation distributions show the scaling behavior. Further, the size distribution resembles that for submonolayer homoepitaxy with the critical island size i = 1, suggesting that detachment of atoms is not significant. The above results also indicate strain is insignificant in determining the nucleation and growth of dislocated islands during heteroepitaxy by MBE.published_or_final_versio

    New high-definition narrow band imaging versus conventional high-definition white light colonoscopy for detection of colorectal adenomas: a randomised controlled trial with tandem colonoscopy

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    This journal suppl. entitled: 19th Medical Research Conference; Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong KongPoster PresentationINTRODUCTION: Adenoma detection is important in colonoscopy as polypectomy has been shown to reduce the subsequent incidence and mortality of colorectal cancer. Narrow band imaging (NBI), an image-enhanced imaging system of the endoscopy, is developed to improve the diagnostic performance of the endoscopy. We tested whether the new generation of NBI colonoscopy would improve detection of colorectal adenoma when compared with high-definition white light (HD-WL) in a randomised tandem colonoscopy study ...postprin
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