Vol. 52 No. 3 (2020)

This paper presents an analysis of cosmic ray intensity in Pakistan air space using spatial interpolation, comparing it with Chinese cosmic ray records from 1984 to 1993. The Exploratory Data Analytic (EDA) approach was applied to compare the cosmic ray fluctuations in both countries. The time series plot of the monthly cosmic rays showed relatively flatter counts in Pakistan than in China. The cosmic ray data for the years 1984 to 1993 fell within Solar Cycle 22, which lasted from 1986 to 1996, with its maximum phase in 1989 to 1991. The cosmic radiation varies between the atmospheric…

The Janus tyrosine kinases (JAKs) have shown great promise as therapeutic protein targets in the treatment of cancer and inflammation diseases. This study used pharmacophore modeling to identify potential inhibitors of Janus kinase 3 (JAK3). A pharmacophore model was developed based on a known JAK3 inhibitor (1NX) and was employed to search for potential JAK3 inhibitors against Indonesian herbal compounds. Among 28 hit molecules that were identified and subjected to a molecular docking protocol against JAK3, the three compounds that had the highest affinities toward JAK3 were camelliaside B,…

One of the most common oral ulcerations is recurrent aphthous stomatitis (RAS), affecting approximately 20% of the general population worldwide. The etiology of RAS is still unclear but it is considered to be multifactorial, including imbalanced nutrition intake and allergic conditions such as atopy. The purpose of this study was to investigate the differences and correlation between the serum level of IL-6, reactive oxygen species (ROS), and cortisol in RAS patients. Our study was cross-sectional and used a consecutive sampling method. There were significant differences of IL-6 and ROS…

The susceptible-infected-recovered (SIR) model of the spread of dengue fever for the case of South Sulawesi is considered. Rangkuti

In this paper, we define subspace-ergodic operators and give examples of these operators. We show that by any given separable infinite-dimensional Banach space, subspace-ergodic operators can be constructed. We demonstrate that an invertible operator T is subspace-ergodic if and only if T-1 is subspace-ergodic. We prove that the direct sum of two subspace-ergodic operators is subspace-ergodic and if the direct sum of two operators is subspace-ergodic, then each of them is subspace-ergodic. Also, we investigate relations between subspace-ergodic and subspace-mixing operators. For example, we…

In this paper we propose an explicit predictor-corrector finite difference scheme to numerically solve one-dimensional conservation laws with discontinuous flux function appearing in various physical model problems, such as traffic flow and two-phase flow in porous media. The proposed method is based on the second-order MacCormack finite difference scheme and the solution is obtained by correcting first-order schemes. It is shown that the order of convergence is quadratic in the grid spacing for uniform grids when applied to problems with discontinuity. To illustrate some properties of the…

In this paper, several parameters of the non-linear Hirota-Satsuma coupled KdV system were estimated using a hybrid between the Firefly Algorithm (FFA) and the Modified Adomian decomposition method (MADM). It turns out that optimal parameters can significantly improve the solutions when using a suitably selected fitness function for this problem. The results obtained show that the approximate solutions are highly compatible with the exact solutions and that the hybrid method FFA_MADM gives higher efficiency and accuracy compared to the classic MADM method.