Search results for "maximum likelihood"
showing 10 items of 53 documents
gllvm: Fast analysis of multivariate abundance data with generalized linear latent variable models inr
2019
The work of J.N. was supported by the Wihuri Foundation. The work of S.T. was supported by the CRoNoS COST Action IC1408.F.K.C.H. was also supported by an ANU cross disciplinary grant.
A multi-site study to classify semi-natural grassland types
2009
International audience; Calibration and validation of simulation models describing herbage growth or feed quality of seminatural grasslands is a complex task for agronomists without investing effort into botanical surveys. To facilitate such modelling efforts, a limited number of grassland types were identified using a functional classification of species. These grassland types were characterized by three descriptors required to model herbage growth or feed quality: the abundance-weighted mean leaf dry matter content across grass species, the relative abundance of grasses, and an estimate of species richness. We conducted a multi-site analysis over 749 grasslands from eight temperate region…
A Dirichlet Autoregressive Model for the Analysis of Microbiota Time-Series Data
2021
Growing interest in understanding microbiota dynamics has motivated the development of different strategies to model microbiota time series data. However, all of them must tackle the fact that the available data are high-dimensional, posing strong statistical and computational challenges. In order to address this challenge, we propose a Dirichlet autoregressive model with time-varying parameters, which can be directly adapted to explain the effect of groups of taxa, thus reducing the number of parameters estimated by maximum likelihood. A strategy has been implemented which speeds up this estimation. The usefulness of the proposed model is illustrated by application to a case study.
A heuristic, iterative algorithm for change-point detection in abrupt change models
2017
Change-point detection in abrupt change models is a very challenging research topic in many fields of both methodological and applied Statistics. Due to strong irregularities, discontinuity and non-smootheness, likelihood based procedures are awkward; for instance, usual optimization methods do not work, and grid search algorithms represent the most used approach for estimation. In this paper a heuristic, iterative algorithm for approximate maximum likelihood estimation is introduced for change-point detection in piecewise constant regression models. The algorithm is based on iterative fitting of simple linear models, and appears to extend easily to more general frameworks, such as models i…
Direct and Indirect Effects of Function in Associated Variables Such as Depression and Severity on Pain Intensity in Women with Carpal Tunnel Syndrome
2015
Objective To determine the direct and indirect effects of function on clinical variables such as age, pain intensity, years of the disease, severity of symptoms, and depression in women with electrodiagnostic and clinical diagnosis of carpal tunnel syndrome (CTS). Design A cross-sectional study. Setting Patients from an urban hospital referred to a university clinic. Methods Two hundred and forty-four (n = 224) women with CTS were included. Demographic and clinical data, duration of symptoms, function, symptom's severity of the symptoms, pain intensity, and depression were self-reported collected. Correlation and path analysis with maximum likelihood estimation were conducted to assess the …
On incorporating the paradigms of discretization and Bayesian estimation to create a new family of pursuit learning automata
2013
Published version of an article in the journal: Applied Intelligence. Also available from the publisher at: http://dx.doi.org/10.1007/s10489-013-0424-x There are currently two fundamental paradigms that have been used to enhance the convergence speed of Learning Automata (LA). The first involves the concept of utilizing the estimates of the reward probabilities, while the second involves discretizing the probability space in which the LA operates. This paper demonstrates how both of these can be simultaneously utilized, and in particular, by using the family of Bayesian estimates that have been proven to have distinct advantages over their maximum likelihood counterparts. The success of LA-…
Molecular evolution and complete genome sequences in forensic analysis: Neisseria gonorrhoeae in a transmission case
2019
Molecular epidemiology and phylogenetic analyses are frequently used in the investigation of viral transmission cases in forensic contexts. Here, we present the methods and results of the analysis of a bacterial transmission in an alleged child abuse case using complete genome sequences obtained by high-throughput sequencing (HTS) methods.
An Improved Detection Technique for Cyclic-Prefixed OFDM
2010
A novel Orthogonal Frequency Division Multiplexing detection technique compatible to standard (e.g. Wireless LAN) transmitters is proposed. It features enhanced error-rate performance with flexible computational complexity and robustness to imperfect channel estimation. It is based on exploitation of the redundancy available in the cyclic prefix after cancellation of interference from the preceding block. In order to show the effectiveness of our proposal, an analysis of computational complexity and a number of comparisons to the standard per-subcarrier receiver and a previously existing method in terms of error rates are reported.
Money in an Estimated Business Cycle Model of the Euro Area
2006
We present maximum likelihood estimates of a small scale dynamic general equilibrium model for the Eurozone. We pay special attention to the role of money, both through its direct effect upon private agents’ decisions and as a component of the monetary policy rule. Our results can be summarized as follows. First, we find no direct effect of money upon inflation and output but money growth plays a significant role in the interest rate rule. Second, money demand shocks mainly help to forecast real balances while real shocks explain the bulk of price, output and interest rates fluctuations. Third, the estimated model predicts sensible conditional correlations among those variables both to dema…
Effects of the European Monetary Union on High-Technology Exports
2021
AbstractOur study estimates the effects of the European Monetary Union (EMU) on high-technology (HT) export and assesses the potential knowledge spillovers of such trade. Irrespective of the importance of the HT trade channel, none of the previous studies in the literature focus on the effects of a common currency on HT trade. Increasing trade in the HT sector may lead to more efficient use of resources and help countries to move towards a knowledge-based economy. Moreover, it may lead to higher overall growth. After considering multilateral resistances, pair fixed effects and bias correction in the preferred (three-way bias-corrected) model, EMU membership becomes negative and statisticall…