Conditional Autoregressive (CAR) Model

Author(s):  
Alexandra M. Schmidt ◽  
Widemberg S. Nobre
2021 ◽  
Vol 2 (1) ◽  
pp. 28-34
Author(s):  
SANDIKA S. RAJAK ◽  
SUMARNO ISMAIL ◽  
RESMAWAN RESMAWAN

This research discusses the use of CAR model in finding out factors that significantly influence TBC transmission and figuring out its transmission patterns in Gorontalo city. The methods apply CAR model aiming to discover factors that significantly influence TBC transmission and Moran's Index aiming to identify its transmission pattern Findings reveal that the number of impoverished population and highlands in Gorontalo city are factors that significantly influence disease transmission The transmission patterns also indicate positive spatial autocorrelation that signifies a similar category among sub-districts


Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 545
Author(s):  
Dwi Rantini ◽  
Nur Iriawan ◽  
Irhamah Irhamah

In spatial data analysis, the prior conditional autoregressive (CAR) model is used to express the spatial dependence on random effects from adjacent regions. This paper provides a new proposed approach regarding the development of the existing normal CAR model into a more flexible, Fernandez–Steel skew normal (FSSN) CAR model. This approach is able to capture spatial random effects that have both symmetrical and asymmetrical patterns. The FSSN CAR model is built on the basis of the normal CAR with an additional skew parameter. The FSSN distribution is able to provide good estimates for symmetry with heavy- or light-tailed and skewed-right and skewed-left data. The effects of this approach are demonstrated by establishing the FSSN distribution and FSSN CAR model in spatial data using Stan language. On the basis of the plot of the estimation results and histogram of the model error, the FSSN CAR model was shown to behave better than both models without a spatial effect and with the normal CAR model. Moreover, the smallest widely applicable information criterion (WAIC) and leave-one-out (LOO) statistical values also validate the model, as FSSN CAR is shown to be the best model used.


Author(s):  
Giancarlo Alfonsi ◽  
Agostino Lauria ◽  
Leonardo Primavera

Author(s):  
Maria Aline Gonçalves ◽  
Rodrigo Tumolin Rocha ◽  
Frederic Conrad Janzen ◽  
José Manoel Balthazar ◽  
Angelo Marcelo Tusset

2010 ◽  
Vol 49 (3) ◽  
pp. 463-480 ◽  
Author(s):  
Damien Maher ◽  
Paul Young

2021 ◽  
Vol 31 (4) ◽  
Author(s):  
Duncan Lee ◽  
Kitty Meeks ◽  
William Pettersson

AbstractSpatio-temporal count data relating to a set of non-overlapping areal units are prevalent in many fields, including epidemiology and social science. The spatial autocorrelation inherent in these data is typically modelled by a set of random effects that are assigned a conditional autoregressive prior distribution, which is a special case of a Gaussian Markov random field. The autocorrelation structure implied by this model depends on a binary neighbourhood matrix, where two random effects are assumed to be partially autocorrelated if their areal units share a common border, and are conditionally independent otherwise. This paper proposes a novel graph-based optimisation algorithm for estimating either a static or a temporally varying neighbourhood matrix for the data that better represents its spatial correlation structure, by viewing the areal units as the vertices of a graph and the neighbour relations as the set of edges. The improved estimation performance of our methodology compared to the commonly used border sharing rule is evidenced by simulation, before the method is applied to a new respiratory disease surveillance study in Scotland between 2011 and 2017.


RSC Advances ◽  
2018 ◽  
Vol 8 (69) ◽  
pp. 39602-39610
Author(s):  
Hailiu Fan ◽  
Jianbang Xuan ◽  
Xinyun Du ◽  
Ningzhi Liu ◽  
Jianlan Jiang

CAR models for the Fuzi–Gancao herb pair were constructed by BP, SVR, GA and PSO, and used to fit experimental data. The main active antitumor components were recognized from MIVs based on the optimal CAR model.


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