Monthly data about oil production at several drilling wells is an example of
spatio-temporal data. The aim of this research is to propose nonlinear spatio-temporal
model, i.e. Feedforward Neural Network - VectorAutoregressive (FFNN-VAR) and FFNN
- Generalized Space-Time Autoregressive (FFNN-GSTAR), and compare their forecast
accuracy to linearspatio-temporal model, i.e. VAR and GSTAR. These spatio-temporal
models are proposed and applied for forecasting monthly oil production data at three
drilling wells in East Java, Indonesia. There are 60 observations that be divided to two
parts, i.e. the first 50 observations for training data and the last 10 observations for
testing data. The results show that FFNN-GSTAR(11) and FFNN-VAR(1) as nonlinear
spatio-temporal models tend to give more accurate forecast than VAR(1) and GSTAR(11)
as linear spatio-temporal models. Moreover, further research about nonlinear spatiotemporal
models based on neural networks and GSTAR is needed for developing new
hybrid models that could improve the forecast accuracy.
A total of 170 bambara groundnut (Vigna subterranea) accessions were evaluated using both simple sequence repeat (SSR) and single nucleotide polymorphism (SNP) markers generated using genotyping-by-sequencing (GbS), of which 56 accessions were collected from West and East Java. Principal coordinate analysis (PCoA), population structure, and cluster analysis suggest that the East Java accessions could be a result of the introduction of selected West Java accessions. In addition, the current Indonesian accessions were likely introduced from Southern Africa, which would have produced a very marked founding effect such that these accessions present only a fraction of the genetic variability that exists within this species.