Search results for "probability"

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.

Endocrine therapy of breast cancer. The experience of the Italian Cooperative Group for Chemohormonal Therapy of Early Breast Cancer (GROCTA).

1993

Voltage collapse proximity indicators for radial distribution networks

2007

Based on the single-line equivalent system of a radial distribution network, two simple methods to evaluate two efficient voltage collapse proximity indicators are presented and discussed. The two methods differ on the determination of the parameters which define the equivalent system from which the indicators are derived. Both methods can be conveniently used jointly for on-line applications to assess the state of a distribution system from the viewpoint of voltage stability; the first to monitoring the stability margin of the whole system loading, the second to sharpen the stability analysis at the critical node when the system operating point is in the vicinity of the loadability limit. …

Optimal Power Flow in three-phase islanded microgrids with inverter interfaced units

2015

In this paper, the solution of the Optimal Power Flow (OPF) problem for three phase islanded microgrids is studied, the OPF being one of the core functions of the tertiary regulation level for an AC islanded microgrid with a hierarchical control architecture. The study also aims at evaluating the contextual adjustment of the droop parameters used for primary voltage and frequency regulation of inverter interfaced units. The work proposes a mathematical method for the OPF solution also considering the droop parameters as variables. The output of the OPF provides an iso-frequential operating point for all the generation units and a set of droop parameters for primary regulation. In this way, …

Galerkin Scheme-Based Determination of Survival Probability of Oscillators With Fractional Derivative Elements

2016

In this paper, an approximate semi-analytical approach is developed for determining the first-passage probability of randomly excited linear and lightly nonlinear oscillators endowed with fractional derivative elements. The amplitude of the system response is modeled as one-dimensional Markovian process by employing a combination of the stochastic averaging and the statistical linearization techniques. This leads to a backward Kolmogorov equation which governs the evolution of the survival probability of the oscillator. Next, an approximate solution of this equation is sought by resorting to a Galerkin scheme. Specifically, a convenient set of confluent hypergeometric functions, related to …

The Probability Law for Generic Density Operators

2020

In this chapter, the probability law of the non-null eigenstates of a generic density operator—studied in the previous chapter—is determined, by showing that given the composite system and the subsystem being considered, a mapping arises which associates a universal probability distribution to the non-null eigenstates of the generic density operator. We thus recover the Born statistical interpretation without having assumed it as a postulate.

Nonlinear spectral shaping and optical rogue events in fiber-based systems

2012

International audience; We provide an overview of our recent work on the shaping and stability of optical continua in the long pulse regime. Fibers with normal group-velocity dispersion at all-wavelengths are shown to allow for highly coherent continua that can be nonlinearly shaped using appropriate initial conditions. In contrast, supercontinua generated in the anomalous dispersion regime are shown to exhibit large fluctuations in the temporal and spectral domains that can be controlled using a carefully chosen seed. A particular example of this is the first experimental observation of the Peregrine soliton which constitutes a prototype of optical rogue-waves.

Extreme Statistics in Raman Fiber Amplifiers: From Analytical Description to Experiments

2011

International audience; In this work, we investigate the emergence of rare and intense events during the Raman fiber amplification of a continuous wave. We highlight how dispersive properties and pump depletion can strongly influence the statistical properties of the amplified signal and its optical spectrum. Under certain conditions, the probability density functions of the amplified signal are calculated analytically and compared with the results of the numerical simulations. The conclusions are qualitatively validated by experiments carried out at telecommunication wavelengths.

A fast algorithm for muon track reconstruction and its application to the ANTARES neutrino telescope.

2011

An algorithm is presented, that provides a fast and robust reconstruction of neutrino induced upward-going muons and a discrimination of these events from downward-going atmospheric muon background in data collected by the ANTARES neutrino telescope. The algorithm consists of a hit merging and hit selection procedure followed by fitting steps for a track hypothesis and a point-like light source. It is particularly well-suited for real time applications such as online monitoring and fast triggering of optical follow-up observations for multi-messenger studies. The performance of the algorithm is evaluated with Monte Carlo simulations and various distributions are compared with that obtained …

Adaptive design optimization: a mutual information-based approach to model discrimination in cognitive science.

2010

Discriminating among competing statistical models is a pressing issue for many experimentalists in the field of cognitive science. Resolving this issue begins with designing maximally informative experiments. To this end, the problem to be solved in adaptive design optimization is identifying experimental designs under which one can infer the underlying model in the fewest possible steps. When the models under consideration are nonlinear, as is often the case in cognitive science, this problem can be impossible to solve analytically without simplifying assumptions. However, as we show in this letter, a full solution can be found numerically with the help of a Bayesian computational trick d…