Search results for "Markov"
showing 10 items of 628 documents
A sliding mode approach to H∞ non-fragile observer-based control design for uncertain Markovian neutral-type stochastic systems
2015
This paper is focused on designing an H ∞ sliding-mode control for a class of neutral-type stochastic systems with Markovian switching parameters and nonlinear uncertainties. An H ∞ non-fragile observer subjected to the transition rates of the switching mode is firstly constructed. By some specified matrices, the connections among the designed sliding surfaces corresponding to every mode are established. Then, the state-estimation-based sliding mode control law is designed to guarantee the reachability of the sliding surface in finite time interval. Furthermore, a stochastic stability criterion is established for all admissible uncertainties, which can guarantee the error system and sliding…
A mobility analysis of the occupational status of the graduates of the University of Palermo in an economic crisis context
2019
In such a global economic crisis context, our aims are describing the mobility of the Palermitan graduates in the labour market, identifying the variables that influence most their occupational status and finally outlining a transition probability structure among the states: Work, Search for a Job, Study, Other. The availability of a large amount of longitudinal data provided by the surveys carried out by STELLA (Statistics about Graduates and Labour Market) allowed us to analyze the mobility of the graduates of the University of Palermo among the different occupational states in three different times. We analyze data coming from a disproportionate stratified sample of graduates in 2009, in…
Population pharmacokinetic model of lithium and drug compliance assessment.
2016
Population pharmacokinetic analysis of lithium during therapeutic drug monitoring and drug compliance assessment was performed in 54 patients and 246 plasma concentrations levels were included in this study. Patients received several treatment cycles (1-9) and one plasma concentration measurement for each patient was obtained always before starting next cycle (pre-dose) at steady state. Data were analysed using the population approach with NONMEM version 7.2. Lithium measurements were described using a two-compartment model (CL/F=0.41Lh-1, V1/F=15.3L, Q/F=0.61Lh-1, and V2/F = 15.8L) and the most significant covariate on lithium CL was found to be creatinine clearance (reference model). Lith…
Utility-based criteria for selecting patients with hepatocellular carcinoma for liver transplantation: A multicenter cohort study using the alpha-fet…
2015
The lifetime utility of liver transplantation (LT) in patients with hepatocellular carcinoma (HCC) is still controversial. The aim of this study was to ascertain when LT is cost-effective for HCC patients, with a view to proposing new transplant selection criteria. The study involved a real cohort of potentially transplantable Italian HCC patients (n = 2419 selected from the Italian Liver Cancer group database) who received nontransplant therapies. A non-LT survival analysis was conducted, the direct costs of therapies were calculated, and a Markov model was used to compute the cost utility of LT over non-LT therapies in Italian and US cost scenarios. Post-LT survival was calculated using t…
Osimertinib in first-line treatment of advanced EGFR-mutated non-small-cell lung cancer: a cost–effectiveness analysis
2019
Aim: Osimertinib improves progression-free survival in first-line EGFR mutation–positive non-small-cell lung cancer. Materials & methods: A Markov cohort model including costs, utilities and disutilities, was conducted to estimate quality-adjusted life-year (QALY) and incremental cost–effectiveness ratio when treating with osimertinib versus standard first-line tyrosine kinase inhibitors (TKIs). Results: Osimertinib presented higher QALYs (0.61) compared with standard EGFR–TKIs (0.42). Osimertinib costs were €83,258.99, in comparison with €29,209.45 for the standard EGFR–TKIs. An incremental cost–effectiveness ratio of €273,895.36/QALY was obtained for osimertinib. Conclusion: Osimerti…
An Ordinal Joint Model for Breast Cancer
2017
We propose a Bayesian joint model to analyze the association between longitudinal measurements of an ordinal marker and time to a relevant event. The longitudinal process is defined in terms of a proportional-odds cumulative logit model and the time-to-event process through a left-truncated Cox proportional hazards model with information of the longitudinal marker and baseline covariates. Both longitudinal and survival processes are connected by a common vector of random effects.
H<inf>&#x221E;</inf> synchronization of Markovian jump master-slave systems with delay
2012
The problem of synchronization is investigated for a class of master-slave systems with time-varying delays and Markovian switching parameters. Using an appropriate Lyapunov-Krasovskii functional, a synchronization law which includes the master-slave parameters is established for designing a mode-dependent output feedback control law in terms of LMIs. A numerical example is given to show the effectiveness of the method.
An Output Feedback Control Design for $$ {\rm H}_\infty $$ Synchronization of Master-Slave Markovian Jump Systems with Time-Varying Delays
2012
In this chapter, an output feedback control proach is proposed for exponential synchronization problem of master slave systems with both discrete and distributed time-varying delays and Markovian switching parameters. Using an appropriate Lyapunov Krasovskii functional, some delay-dependent sufficient conditions and a synchronization law which include the master slave parameters are established for designing a mode-dependent output feedback control law in terms of linear matrix inequalities. The controller guarantees the \( {\rm{H}}_\infty \) synchronization of the two coupled master and slave systems regardless of their initial states. A numerical example is given to show the effectiveness…
Google matrix analysis of worldwide football mercato
2018
[EN] The worldwide football transfer market is analyzed as a directed complex network: the football clubs are the network nodes and the directed edges are weighted by the total amount of money transferred from a club to another. The Google matrix description allows to treat every club independently of their richness and allows to measure for a given club the efficiency of player sales and player acquisitions. The PageRank algorithm, developed initially for the World Wide Web, naturally characterizes the ability of a club to import players. The CheiRank algorithm, also developed to analyze large scale directed complex networks, characterizes the ability of a club to export players. The analy…
M/M/1 queue in two alternating environments and its heavy traffic approximation
2018
We investigate an M/M/1 queue operating in two switching environments, where the switch is governed by a two-state time-homogeneous Markov chain. This model allows to describe a system that is subject to regular operating phases alternating with anomalous working phases or random repairing periods. We first obtain the steady-state distribution of the process in terms of a generalized mixture of two geometric distributions. In the special case when only one kind of switch is allowed, we analyze the transient distribution, and investigate the busy period problem. The analysis is also performed by means of a suitable heavy-traffic approximation which leads to a continuous random process. Its d…