26 research outputs found

    Artificial Intelligence based Position Detection for Hydraulic Cylinders using Scattering Parameters

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    Position detection of hydraulic cylinder pistons is crucial for numerous industrial automation applications. A typical traditional method is to excite electromagnetic waves in the cylinder structure and analytically solve the piston position based on the scattering parameters measured by a sensor. The core of this approach is a physical model that mathematically describes the relationship between the measured scattering parameters and the targeted piston position. However, this physical model has shortcomings in accuracy and adaptability, especially in extreme conditions. To overcome this problem, we propose Artificial Intelligence (AI)-based methods to learn the relationship directly data-driven. As a result, all Artificial Neural Network (ANN) models in this paper consistently outperform the physical one by a large margin. Given the success of AI-based models for our task, we further deliberate the choice of models based on domain knowledge and provide in-depth analyses combining model performance with the physical characteristics. Specifically, we use Convolutional Neural Network (CNN)s to discover local interactions of input among adjacent frequencies, apply Complex-Valued Neural Network (CVNN) to exploit the complex-valued nature of electromagnetic scattering parameters, and introduce a novel technique named Frequency Encoding to add weighted frequency information to the model input. By combining these three techniques, our best performing model, a complex-valued CNN with Frequency Encoding, manages to significantly reduce the test error to hardly 1/12 of the one given by the traditional physical model.Comment: 16 pages, 10 figure

    Six sequence variants on chromosome 9p21.3 are associated with a positive family history of myocardial infarction: a multicenter registry

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    <p>Abstract</p> <p>Background</p> <p>Recent genome-wide association studies have identified several genetic loci linked to coronary artery disease (CAD) and myocardial infarction (MI). The 9p21.3 locus was verified by numerous replication studies to be the first common locus for CAD and MI. In the present study, we investigated whether six single nucleotide polymorphisms (SNP) rs1333049, rs1333040, rs10757274, rs2383206, rs10757278, and rs2383207 representing the 9p21.3 locus were associated with the incidence of an acute MI in patients with the main focus on the familial aggregation of the disease.</p> <p>Methods</p> <p>The overall cohort consisted of 976 unrelated male patients presenting with an acute coronary syndrome (ACS) with ST-elevated (STEMI) as well as non-ST-elevated myocardial infarction (NSTEMI). Genotyping data of the investigated SNPs were generated and statistically analyzed in comparison to previously published findings of matchable control cohorts.</p> <p>Results</p> <p>Statistical evaluation confirmed a highly significant association of all analyzed SNP's with the occurrence of MI (p < 0.0001; OR: 1.621-2.039). When only MI patients with a positive family disposition were comprised in the analysis a much stronger association of the accordant risk alleles with incident disease was found with odds ratios up to 2.769.</p> <p>Conclusions</p> <p>The findings in the present study confirmed a strong association of the 9p21.3 locus with MI particularly in patients with a positive family history thereby, emphasizing the pathogenic relevance of this locus as a common genetic cardiovascular risk factor.</p

    Конкурентоспособность фирм в условиях рыночной экономики

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    Анализ эффективности организации коммерческой деятельности предприятия и оценка конкурентоспособности фирмы. Исследование и разработка системы повышения конкурентоспособности предприятия рынка рекламных услуг.Analysis of the effectiveness of the organization of commercial activities of the enterprise and evaluation of the firm's competitiveness. Research and development of a system for increasing the competitiveness of a service enterprise

    Effect and safety of treatment with ACE-inhibitor Enalapril and β-blocker metoprolol on the onset of left ventricular dysfunction in Duchenne muscular dystrophy - a randomized, double-blind, placebo-controlled trial

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    Background: X-linked Duchenne muscular dystrophy (DMD), the most frequent human hereditary skeletal muscle myopathy, inevitably leads to progressive dilated cardiomyopathy. We assessed the effect and safety of a combined treatment with the ACE-inhibitor enalapril and the β-blocker metoprolol in a German cohort of infantile and juvenile DMD patients with preserved left ventricular function. Methods, Trial design: Sixteen weeks single-arm open run-in therapy with enalapril and metoprolol followed by a two-arm 1:1 randomized double-blind placebo-controlled treatment in a multicenter setting. Inclusion criteria: DMD boys aged 10–14 years with left ventricular fractional shortening [LV-FS] ≥ 30% in echocardiography. Primary endpoint: time from randomization to first occurrence of LV-FS &lt; 28%. Secondary: changes of a) LV-FS from baseline, b) blood pressure, c), heart rate and autonomic function in ECG and Holter-ECG, e) cardiac biomarkers and neurohumeral serum parameters, f) quality of life, and g) adverse events. Results: From 3/2010 to 12/2013, 38 patients from 10 sites were centrally randomized after run-in, with 21 patients continuing enalapril and metoprolol medication and 17 patients receiving placebo. Until end of study 12/2015, LV-FS &lt; 28% was reached in 6/21 versus 7/17 patients. Cox regression adjusted for LV-FS after run-in showed a statistically non-significant benefit for medication over placebo (hazard ratio: 0.38; 95% confidence interval: 0.12 to 1.22; p = 0.10). Analysis of secondary outcome measures revealed a time-dependent deterioration of LV-FS with no statistically significant differences between the two study arms. Blood pressure, maximal heart rate and mean-NN values were significantly lower at the end of open run-in treatment compared to baseline. Outcome analysis 19 months after randomization displayed significantly lower maximum heart rate and higher noradrenalin and renin values in the intervention group. No difference between treatments was seen for quality of life. As a single, yet important adverse event, the reversible deterioration of walking abilities of one DMD patient during the run-in period was observed. Conclusions: Our analysis of enalapril and metoprolol treatment in DMD patients with preserved left ventricular function is suggestive to delay the progression of the intrinsic cardiomyopathy to left ventricular failure, but did not reach statistical significance, probably due to insufficient sample size. Clinical trial registration: DRKS-number 00000115, EudraCT-number 2009–009871-36

    Detection of hepatitis B virus in serum using amplification of viral DNA by means of the polymerase chain reaction

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    A new assay was developed for the detection of hepatitis B virus (HBV) in human serum using amplification of a short viral DNA sequence by means of the polymerase chain reaction. As little as 0.4 fg viral DNA, corresponding to about 130 genome equivalents, per ml serum could be detected after the amplification procedure. This assay detected viral DNA in a number of patients with proven or suspected chronic HBV infection who were all negative for HBV DNA in the conventional hybridisation assay. We found HBV DNA in all of six HBeAg-positive and in three of eight HBeAg-negative HBsAg carriers, as well as in all of 11 patients with chronic liver disease with antibodies against the HBV core antigen (anti-HBc) as the sole marker for HBV infection, and in three of five apparently healthy individuals showing only anti HBc. Thus, this method is an important improvement for the diagnosis of persistent HBV infections, especially in patients where a definitive serological diagnosis is not possible

    Mechanisms of histamine-induced coronary vasodilatation: H1-receptor-mediated release of endothelium-derived nitric oxide

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    Although the content of histamine in myocardial tissue is high, its contribution to the regulation of coronary blood flow has not been clearly defined. The aim of the present study was to investigate whether or not nitric oxide (NO), an important modulator of coronary vascular tone, is involved in histamine-induced coronary vasomotion and to characterize which histaminergic receptor subtype mediates this process. Isolated, constant-flow-perfused guinea pig hearts were challenged with histamine, the H1-receptor agonist pyridylethylamine (PYR) and the H2-receptor agonist dimaprit (DIM). Apart from coronary perfusion pressure (CPP), left ventricular pressure (LVP) and the development of contractile force (dp/dt), the release of NO and cyclic GMP (cGMP) were continuously measured. Histamine and DIM induced concentration dependently a coronary vasodilatation with an almost 50% decrease in CPP paralleled by an enhancement of LVP and dp/dt by more than 80%. PYR selectively reduced CPP by 47% without affecting LVP and dp/dt. Histamine- and PYR-induced coronary vasodilatation were paralleled by a more-than-twofold increase in basal cGMP release from isolated hearts, whereas DIM exerted no effects on cGMP release. Oxyhemoglobin (4 µM), an effective scavenger of NO, shifted the concentration-response curve for histamine- and PYR-induced changes in CPP significantly to the right and in parallel inhibited the increase in cGMP release. Histamine and PYR rapidly (within 2 s) decreased CPP, while the onset of DIM-induced coronary vasodilatation followed changes in LVP with a lag period of 10 s. Histamine increased basal NO release concentration dependently by a maximum of 351 ± 21 pmol/min
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