Sökresultat

In this article, we propose generalized two-parameter (GTP) estimators and an algorithm for the estimation of shrinkage parameters to combat multicollinearity in the multinomial logit regression model. In addition, the mean squared error properties of the estimators are derived. A simulation study is conducted to investigate the performance of proposed estimators for different sample sizes, degree

This paper introduces a new class of efficient and debiased two-step shrinkage estimators for a linear regression model in the presence of multicollinearity. We derive the proposed estimators’ mean square error and define the necessary and sufficient conditions for superiority over the existing estimators. In addition, we develop an algorithm for selecting the shrinkage parameters for the proposed

Future climate scenarios are predicting considerable threats to sustainable maize production in arid and semi-arid regions. These adverse impacts can be minimized by adopting modern agricultural tools to assess and develop successful adaptation practices. A multi-model approach (climate and crop) was used to assess the impacts and uncertainties of climate change on maize crop. An extensive field s

In this article, we propose a restricted gamma ridge regression estimator (RGRRE) by combining the gamma ridge regression (GRR) and restricted maximum likelihood estimator (RMLE) to combat multicollinearity problem for estimating the parameter (Formula presented.) in the gamma regression model. The properties of the new estimator are discussed, and its superiority over the GRR, RMLE and traditiona

This article investigates the performance of several residuals for the Cox proportional hazards regression model to diagnose the influential observations. The standardized and adjusted forms of residuals are proposed for Cox proportional hazards regression model. In addition, Cook’s distance is proposed for both standardized and adjusted residuals. The assessment of different residuals for the ide

A model, based on the solution of two coupled diffusion equations to the excitation and emission wavelengths, respectively, was developed to describe the Raman signal in the time domain in a reflectance configuration in a two-layer medium. The accuracy of the model is characterized by comparison with the results of Monte Carlo simulations. This solver can correctly account for the Raman emitters w

Soluble urokinase plasminogen activator receptor (suPAR) is an inflammatory marker that has been shown to predict poorer outcomes in cardiovascular disease and after cardiac surgery. The relationship between suPAR concentrations and postoperative complications after valvular surgery, however, remains unclear. This study aims to evaluate the predictive value of suPAR concentrations for infection, a

Hård konkurrens och osäkra anställningar inom akademin skapar dåliga förutsättningar för både forskning och yrkesbana. Kvinnor drabbas särskilt hårt och deras karriärer stagnerar när de får barn. Forskarpapporna då? De är till synes opåverkade och fortsätter att publicera i allt högre tempo, skriver ekonomiforskaren Olof Ejermo i en ny rapport.

The European Spallation Source (ESS) is a research facility under construction aiming to be the world’s most powerful pulsed neutron source. It is powered by a complex particle accelerator designed to provide a 2.86 ms long proton pulse at 2 GeV with a repetition rate of 14 Hz. Commissioning of the first part of the accelerator has begun and the requirements on the control system interfaces varies

The European Spallation Source (ESS) is a research facility under construction aiming to be the world’s most powerful pulsed neutron source. It is powered by a complex particle accelerator designed to provide a 2.86 ms long proton pulse at 2 GeV with a repetition rate of 14 Hz. Protons are accelerated via cavity fields through various accelerating structures that are powered by Radio-Frequency (RF

Electrical storm (ES) presents a difficult management problem that has predominantly been described in adults and there are limited published data relating to children. We set out to characterize ES in children to assist management based on published literature and own institutional experience. We retrospectively analyzed the records of children presenting with ES to our institution between July 2