This study aims to implement Bayesian quantile regression method in constructing the model of Low Birth Weight. The data of Low Birth Weight is violated of nonnormal assumption for error terms. This study considers quantile regression approach and use Gibbs sampling algorithm from Bayesian method for fitting the quantile regression model. This study explores the performance of the asymmetric Laplace distribution for working likelihood in posterior estimation process. This study also compare the result of variable selection in quantile regression and Bayesian quantile regression for Low Birth Weight model. This study. proved that Bayesan quantile method produced better model than just quantile approach. Bayesian quantile method proved that it can handle the nonnormal problem although using moderate size of data.

Bird flu infection processes within a poultry farm are formulated mathematically. A spatial effect is taken into account for the virus concentration with a diffusive term. An infection process is represented in terms of a traveling wave solutions. For a small removal rate, a singular perturbation analysis lead to existence of traveling wave solutions, that correspond to progressive infection in one direction.

In this paper, we analyse the bifurcation of epidemic models. Those model is waning immunity. First, the stability of those system is analyzed by analyzing the stability of critical points. The threshold number that associated with the stability was determined. Later, the existence of bifurcation was analyzed. The result show that bifurcation exist and threshold number is considered as bifurcation parameter. Numerical simulation is given to confirm the analytical results by showing the graphic solutions and phase portrait.

Vaksinasi adalah salah satu cara untuk mengendalikan sekaligus mencegah penyebaran penyakit menular. Tingkat vaksinasi yang diberikan kepada individu dalam suatu populasi, menentukan apakah populasi tersebut tahan atau tidak terhadap penyakit. Penelitian ini mengembangkan model SIR (susceptible, infected, recovered) tanpa dan dengan vaksinasi. Perilaku solusi dari kedua model dianalisis melalui analisis kestabilan di sekitar titik-titik ekuilibriumnya. Kestabilan tersebut juga dikaitkan dengan nilai ambang batas yang menandakan apakah ppopulasi bebas atau terinfeksi penyakit. Hasil analitik dikonfirmasi dengan hasil numerik.

The prey predator interaction is fundamental and important process in a population dynamic. In this paper, a diffusive prey predator holling type II model considering limitation of the prey growth is presented. The model consists two distinct populations. Model is a nonlinear system of partial differential equations which is a initial boundary value problem. The behaviour solution of the model was analyzed by analyzing stability of the critical point. In solving this system, we use Homogeneous Neumann boundary conditions. Numerical solution was determined by using finite difference method. The results show that the diffusive model illustrates a spreading population over a limited area.