Results 261 to 270 of about 12,179,068 (306)

Fixed Effects and Random Effects

2008
One of the major benefits from using panel data as compared to cross-section data on individuals is that it enables us to control for individual heterogeneity. Not controlling for these unobserved individual specific effects leads to bias in the resulting estimates.
openaire   +1 more source

On the Unidentifiability of the Fixed-Effects 3PL Model

Psychometrika, 2015
The paper offers a general review of the basic concepts of both statistical model and parameter identification, and revisits the conceptual relationships between parameter identification and both parameter interpretability and properties of parameter estimates. All these issues are then exemplified for the 1PL, 2PL, and 1PL-G fixed-effects models.
San Martín, Ernesto, González Burgos, Jorge Andrés, Tuerlinckx, Francis   +2 more
openaire   +4 more sources

Latent Variable Models with Fixed Effects

Biometrics, 1996
We discuss latent variable models that allow for fixed effect covariates, as well as covariates affecting the latent variable directly. Restricted maximum likelihood and maximum likelihood are used to estimate model parameters. A generalized likelihood ratio test can be used to test significance of the covariates effecting the latent outcomes.
Sammel, Mary Dupuis, Ryan, Louise M.
openaire   +2 more sources

Are Fixed Effects Fixed? [PDF]

, 1997
In attempts to overcome the problem of omitted variables, the assumption of fixed effects is widely implemented when working with panel data. This paper examines the validity of this technique, in the context of estimating a production function using panels of US textile plants.
openaire  

Fixed Effect Models and Fixed Coefficient Models

1992
As noted in the introductory chapter, the simplest and most intuitive way to account for individual and/or time differences in behaviour, in the context of a panel data regression problem, is to assume that some of the regression coefficients are allowed to vary across individuals and/or through time.
openaire   +1 more source

Chitinase and peroxidase in effective (fix+) and ineffective (fix?) soybean nodules

Planta, 1992
Chitinase and peroxidase, two enzymes thought to be involved in the defense of plants against pathogens, were measured in soybean (Glycine max L. Merr.) roots and in nodules colonized by Bradyrhizobium japonicum strains differing in their symbiotic potential. Activities of both enzymes were higher in nodules than in roots.
Staehelin C, Müller J, Mellor RB, Wiemken A, Boller T   +4 more
openaire   +3 more sources

Porous fixed-bed photoreactor for boosting C–C coupling in photocatalytic CO2 reduction

EScience, 2022
Ya Liu, Liejin Guo, Shengjie Bai
exaly  

Robust fixed-time tracking control for underactuated AUVs based on fixed-time disturbance observer

Ocean Engineering, 2022
Longjin Wang, Shun An
exaly  

Fixed Effects

2021
openaire   +1 more source

A new fixed-time stability theorem and its application to the fixed-time synchronization of neural networks

Neural Networks, 2020
Chuan Chen, Lixiang Li, Hui Zhao
exaly