27 research outputs found

    Design of a networked control system with random transmission delay and uncertain process parameters

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    This paper discusses the compensation of the transmission delay in a networked control system (NCS) with a state feedback, which possesses a randomly varying transmission delay and uncertain process parameters. The compensation is implemented by using a buffer in the actuator node and a state estimator in the controller node. A Linear Matrix Inequality (LMI) based sufficient condition for the stability of the NCS under the designed compensation is proposed. The simulation results illustrate the efficiency of the compensation method

    Robust stability conditions for remote SISO DMC controller in networked control systems

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    A two level hierarchy is employed in the design of Networked Control Systems (NCSs) with bounded random transmission delay. At the lower level a local controller is designed to stabilize the plant. At the higher level a remote controller with the Dynamic Matrix Control (DMC) algorithm is implemented to regulate the desirable set-point for the local controller. The conventional DMC algorithm is not applicable due to the unknown transmission delay in NCSs. To meet the requirements of a networked environment, a new remote DMC controller is proposed in this study. Two methods, maximum delayed output feedback and multi-rate sampling, are used to cope with the delayed feedback sensory data. Under the assumption that the closed-loop local system is described by one FIR model of an FIR model family, the robust stability problem of the remote DMC controller is investigated. Applying Jury's dominant coefficient lemma and some stability results of switching discrete-time systems with multiple delays; several stability criteria are obtained in the form of simple inequalities. Finally, some numerical simulations are given to demonstrate the theoretical results

    Table1_Association between precocious puberty and obesity risk in children: a systematic review and meta-analysis.docx

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    ObjectivesThe aim of this study was to evaluate the potential association between early onset puberty and the risk of different forms of obesity in children.MethodsThe databases PubMed, EMBASE, Web of Science and Cochrane Library were systematically searched for relevant studies. The odds ratio (OR) and 95% confidence interval (CI) of obesity in precocious puberty were calculated using Stata software 14.0. A fixed-effects model was used if P > 0.1 and I2 ≤ 50%. Otherwise, a random-effects model was used. Publication bias was assessed using funnel plots and Egger's test.ResultThe pooling analysis showed that precocious puberty in girls was associated with a higher risk of obesity (OR = 1.98; 95% CI: 1.76–2.24; I2 = 0.00%, P 2 = 22.2%, P 2 = 0.00%, P 2 = 5.1%, P 2 = 50.6%, P = 0.369). In boys, the occurrence of precocious puberty was not associated with an elevated risk of general obesity (OR = 0.96; 95% CI: 0.40–2.27; I2 = 79.6%, P = 0.922), central obesity (OR = 1.17; 95% CI: 0.96–1.43; I2 = 0.00%, P = 0.125), or overweight (OR = 1.03; 95% CI: 0.56–1.88; I2 = 74.4%, P = 0.930).ConclusionThis meta-analysis suggests that the onset of puberty at an early age in girls is associated with an increased risk of obesity, however precocious puberty in boy was not associated with an increased risk of obesity. These findings highlight that precocious puberty should be considered an independent risk factor for obesity in girls.Systematic Review RegistrationCRD42023404479.</p

    Survival and prognostic indicators of Budd–Chiari syndrome: a systematic review of 79 studies

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    <p>This paper aimed to systematically review the survival of Budd–Chiari syndrome and to identify the most robust prognostic predictors. Overall, 79 studies were included. According to the treatment modalities, the median 1-, 5- and 10-year survival rate was 93, 83 and 73% after interventional radiological treatment; 81, 75 and 72.5% after surgery other than liver transplantation; 82.5, 70.2 and 66.5% after liver transplantation and 68.1, 44.4% and unavailable after medical therapy alone. According to the publication years, the median 1-, 5- and 10-year survival rate was 68.6, 44.4% and unavailable before 1990; 75.1, 69.5 and 57% during the year 1991–1995; 77, 69.6 and 65.6% during the year 1996–2000; 86.5, 74 and 63.5% during the year 2001–2005 and 90, 82.5 and 72% after 2006. Bilirubin, creatinine and ascites were more frequently identified as significant prognostic factors in univariate analyses. But their statistical significance was less frequently achieved in multivariate analyses.</p

    Results of Empirical Study.

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    <p>Results of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0081045#s4" target="_blank">Empirical Study</a>.</p
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