Search results for "DELAYS"
showing 10 items of 42 documents
Input-Output Finite-Time Stability of Discrete-Time Impulsive Switched Linear Systems with State Delays
2013
Published version of an article in the journal: Circuits, Systems, and Signal Processing. Also available from the publisher at: http://dx.doi.org/10.1007/s00034-013-9610-7 This paper is concerned with the problem of input-output finite-time stability (IO-FTS) for discrete impulsive switched systems with state delays. Sufficient conditions are presented for the existence of IO-FTS for such systems under the cases of certain switching, arbitrary switching, and uncertain switching. All the obtained results are formulated in a set of linear matrix inequalities (LMIs). Two numerical examples are given to illustrate the effectiveness of the proposed results.
A Lyapunov–Razumikhin approach for stability analysis of logistics networks with time-delays
2012
Logistics network represents a complex system where different elements that are logistic locations interact with each other. This interaction contains delays caused by time needed for delivery of the material. Complexity of the system, time-delays and perturbations in a customer demand may cause unstable behaviour of the network. This leads to the loss of the customers and high inventory costs. Thus the investigation of the network on stability is desired during its design. In this article we consider local input-to-state stability of such logistics networks. Their behaviour is described by a functional differential equation with a constant time-delay. We are looking for verifiable conditio…
Temporal trends in prehospital management of ST-segment elevation myocardial infarction from 2002 to 2010 in Cote d’Or: Data from the RICO registry (…
2012
Summary Background Myocardial infarction with ST-segment elevation (STEMI) is a medical emergency requiring specific management, with the main aim of achieving reperfusion as quickly as possible. Guidelines from medical societies have defined optimal management, with proven efficacy on morbi-mortality. Aims Our study aimed to evaluate trends in practices between 2002 and 2010 in the emergency management of STEMI in a single French department, namely Cote d’Or. Methods All patients admitted with a first STEMI to one of the six participating coronary care units (private or public) in Cote d’Or since January 2001 were included in a prospective registry (obseRvatoire des Infarctus de Cote d’Or …
Non-office-hours admission affects intravenous thrombolysis treatment times and clinical outcome
2018
In patients treated with intravenous thrombolysis (IVT), an unfavourable ‘non-office-hours effect’ on door-to-needle time (DNT) and clinical outcome has been suggested. This effect has been attributed to a number of factors, mostly related to either less efficient logistics or less (experienced) staffing during non-office hours (NH). These factors could result in longer DNTs and more protocol violations and thus in worse clinical outcome. On the other hand, one could also argue that the workload during NH is lower, which could result in less time delays in the various diagnostic processes and thus in better clinical outcome. Our hypothesis is that admission during NH has a negative effect o…
Design of robust observer for T-S fuzzy time-delayed systems subject to unknown inputs
2013
In this paper, a novel approach is proposed to design a robust observer for a class of Takagi-Sugeno (T-S) fuzzy models with unknown inputs and delays. The main contribution of this paper is to consider unknown inputs and a mixed neutral and discrete delay in the model. Also, the system is subject to disturbances, which are imposed on both state and output signals. Delay-dependent sufficient conditions for the design of an unknown input T-S observer with time delays are given in terms of linear matrix inequalities (LMIs). Some relaxations are introduced by using intermediate variables. A numerical example is given to illustrate the effectiveness of the given results.
Knowledge of alpha-1 deficiency and primary ciliary dyskinesia by medical students and health professionals
2016
Background: Under-diagnosis and delayed diagnosis are common features in rare diseases, which have negative effects on the patients9 prognosis. A possible explanation could be lack of awareness and education of the health professionals involved in the managements of these patients. Alpha-1-antitrypsin deficiency (AATD) and primary ciliary dyskinesia (DCP) are under-diagnosed rare diseases showing a median diagnosis delay of five to ten years. Methods: A survey was undertaken in paediatricians (general, paediatric pulmonologists and paediatric gastroenterologist) and medical school students to assess their knowledge on AATD and PCD. Results: A total of 624 surveys on AATD and 457 on PCD were…
Size of the accretion disk in the gravitationally lensed quasar SDSS J1004+4112 from the statistics of microlensing magnifications
2016
We present eight monitoring seasons of the four brightest images of the gravitational lens SDSS J1004+4112 observed between December 2003 and October 2010. Using measured time delays for the images A, B and C and the model predicted time delay for image D we have removed the intrinsic quasar variability, finding microlensing events of about 0.5 and 0.7 mag of amplitude in the images C and D. From the statistics of microlensing amplitudes in images A, C, and D, we have inferred the half-light radius (at {\lambda} rest = 2407 {\AA}) for the accretion disk using two different methods, $R_{1/2}=8.7^{+18.5}_{-5.5} \sqrt{M/0.3 M_\odot}$ (histograms product) and $R_{1/2} = 4.2^{+3.2}_{-2.2} \sqrt{…
Quantification of synchronization during atrial fibrillation by Shannon entropy: Validation in patients and computer model of atrial arrhythmias
2005
Atrial fibrillation (AF), a cardiac arrhythmia classically described as completely desynchronized, is now known to show a certain amount of synchronized electrical activity. In the present work a new method for quantifying the level of synchronization of the electrical activity recorded in pairs of atrial sites during atrial fibrillation is presented. A synchronization index (Sy) was defined by quantifying the degree of complexity of the distribution of the time delays between sites by Shannon entropy estimation. The capability of Sy to discriminate different AF types in patients was assessed on a database of 60 pairs of endocardial recordings from a multipolar basket catheter. The analysis…
Neural Network Based Finite-Time Stabilization for Discrete-Time Markov Jump Nonlinear Systems with Time Delays
2013
Published version of an article in the journal: Abstract and Applied Analysis. Also available from the publisher at: http://dx.doi.org/10.1155/2013/359265 Open Access This paper deals with the finite-time stabilization problem for discrete-time Markov jump nonlinear systems with time delays and norm-bounded exogenous disturbance. The nonlinearities in different jump modes are parameterized by neural networks. Subsequently, a linear difference inclusion state space representation for a class of neural networks is established. Based on this, sufficient conditions are derived in terms of linear matrix inequalities to guarantee stochastic finite-time boundedness and stochastic finite-time stabi…
Synchronization of Uncertain Neural Networks with H8 Performance and Mixed Time-Delays
2011
An exponential H8 synchronization method is addressed for a class of uncertain master and slave neural networks with mixed time-delays, where the mixed delays comprise different neutral, discrete and distributed time-delays. An appropriate discretized Lyapunov-Krasovskii functional and some free weighting matrices are utilized to establish some delay-dependent sufficient conditions for designing a delayed state-feedback control as a synchronization law in terms of linear matrix inequalities under less restrictive conditions. The controller guarantees the exponential H8 synchronization of the two coupled master and slave neural networks regardless of their initial states. Numerical simulatio…