Search results for "ratio [multiplicity]"

Hypothesis testing for Panels of Semi-Markov Processes with parametric sojourn time distributions

2022

This work deals with the asymptotic properties of maximum likelihood estimators for semi-Markov processes with parametric sojourn time distributions. It is motivated by the comparison, via a two-sample test procedure, of the distribution of two panels of qualitative trajectories modeled by semi-Markov processes and observed over a random number of transitions. Considering first one panel of growing size, we derive, under classical conditions, the convergence in probability of the estimators of the transition probabilities and the parameters of the sojourn time distributions as well as their asymptotic normality. We then consider panels of semi-Markov processes drawn from two different popul…

Housing Affordability in Metropolitan Areas. The Application of a Combination of the Ratio Income and Residual Income Approaches to Two Case Studies …

2017

Housing affordability problems have become more serious over the course of the last few decades and are now also affecting the middle-class, despite the fall in prices on the housing market. This study proposes a methodology to assess threshold-income as an index for measuring housing affordability by applying a combination of the ratio income and residual income approaches. The methodology is applied to two particular areas of Sicily in Italy as case studies consisting of medium-size metropolitan areas located in a less developed European region. The areas have been chosen on the basis of their different territorial structure: a polarized area that comprises a high-density city centre and …

Housing Affordability for Urban Regions

2021

Urban regions are recognised as driving forces of the global economy as well as the main sources of social inequality. In recent decades, particularly, housing access has become a serious problem, not only for the most disadvantaged population, but also for the middle class, as a result of economic crises and despite of prices decline in the housing market. In urban regions with high population density, some social groups face problems of housing affordability that depend not only on market prices but also on income availability. The contribution proposes a methodology for income-threshold assessment through a combination between the ratio income and the residual income approaches, which is…

Real-Time Detection of Incipient Inter-Turn Short Circuit and Sensor Faults in Permanent Magnet Synchronous Motor Drives Based on Generalized Likelih…

2022

This paper presents a robust model-based technique to detect multiple faults in permanent magnet synchronous motors (PMSMs), namely inter-turn short circuit (ITSC) and encoder faults. The proposed model is based on a structural analysis, which uses the dynamic mathematical model of a PMSM in an abc frame to evaluate the system’s structural model in matrix form. The just-determined and over-determined parts of the system are separated by a Dulmage–Mendelsohn decomposition tool. Subsequently, the analytical redundant relations obtained using the over-determined part of the system are used to form smaller redundant testable sub-models based on the number of defined fault terms. Furthermore, fo…

Isotopically (δ13C and δ18O) heavy volcanic plumes from Central Andean volcanoes: a field study

2017

International audience; Stable isotopes of carbon and oxygen in volcanic gases are key tracers of volatile transfer between Earth's interior and atmosphere. Although important, these data are available for few volcanoes because they have traditionally been difficult to obtain and are usually measured on gas samples collected from fumaroles. We present new field measurements of bulk plume composition and stable isotopes (δ13CCO2 and δ18OH2O+CO2) carried out at three northern Chilean volcanoes using MultiGAS and isotope ratio infrared spectroscopy. Carbon and oxygen in magmatic gas plumes of Lastarria and Isluga volcanoes have δ13C in CO2 of +0.76‰ to +0.77‰ (VPDB), similar to slab carbonate;…

Statistical properties of the capacity of Rice channels with MRC and EGC

2009

In this paper, we have studied the statistical properties of the capacity of Rice channels for both maximal ratio combining (MRC) and equal gain combining (EGC) schemes. We have analyzed the effect of the number of diversity branches and the amplitude of the line-of-sight (LOS) components in the diversity branches on the statistics of the channel capacity. Specifically, we have derived analytical expressions for the probability density function (PDF), cumulative distribution function (CDF), level-crossing rate (LCR), and average duration of fades (ADF) of the capacity of Rice channels when using MRC and EGC. It is observed that if the number of diversity branches or the amplitude of the LOS…

Cytokines gene expression in the tunica albuginea in patients with Peyronie’s disease. Pilot study with a control group

2011

INTRODUCTION: We decided to conduct a study to investigate the presence of cytokines in the albuginea of subjects with Peyronie's disease (PD). Cytokines, as responsible for intercellular communication, maybe involved in the pathogenesis of the disease. The identification of one or more involved cytokines may, in fact, be useful in the pharmacological treatment with biologic drugs that are able to interfere with specific cytokines. MATERIALS AND METHODS: Between January 2009 and Decembre 2010 at the Clinic of Urological outpatients clinic of the Policlinico of Palermo were recruited 20 subjects with PD, mean age 62.3 years (range 51-70) and 8 subjects with congenital recurvatum penis (mean …

Trattamento induratio penis plastica: benefici e svantaggi dell'extra-corporeal shock therapy (ESWT). Studio prospettico randomizzato v/s placebo.

2011

Modeling and Mitigating Errors in Belief Propagation for Distributed Detection

2021

We study the behavior of the belief-propagation (BP) algorithm affected by erroneous data exchange in a wireless sensor network (WSN). The WSN conducts a distributed multidimensional hypothesis test over binary random variables. The joint statistical behavior of the sensor observations is modeled by a Markov random field whose parameters are used to build the BP messages exchanged between the sensing nodes. Through linearization of the BP message-update rule, we analyze the behavior of the resulting erroneous decision variables and derive closed-form relationships that describe the impact of stochastic errors on the performance of the BP algorithm. We then develop a decentralized distribute…

Developments in the evolutionary theory of social interactions

2016

Altruistic behaviour, which benefits others but harms the actor, can evolve when copies of the underlying genes are transmitted to future generations by related beneficiaries. While we know that the mechanism of ‘kin selection’ answers to how altruism can evolve, the answers to why and when it can evolve are still obscure. The first aim of this thesis is to shed light to the evolution of altruism by identifying factors that facilitate or promote it. I find that the conditions under which altruism can evolve follow surprisingly simple principles that are independent of the taxon-specific traits such as fecundity. Further, by analysing the unique aspects of haplodiploid sex determination syst…