Journal of Mathematical and Fundamental Sciences <p><img class="imgdesc" src="" alt="" width="173" height="220" /></p> <p style="text-align: justify;"><em>Journal of Mathematical and Fundamental Sciences </em>welcomes full research articles in the area of Mathematics and Natural Sciences from the following subject areas: Astronomy, Chemistry, Earth Sciences (Geodesy, Geology, Geophysics, Oceanography, Meteorology), Life Sciences (Agriculture, Biochemistry, Biology, Health, Medical, Pharmacy), Mathematics, Physics, and Statistics. New submissions of mathematics articles starting in January 2020 are required to focus on applied mathematics with real relevance to the field of natural sciences.</p> <p style="text-align: justify;">Starting from Vol. 1, No. 1, 1961, full articles published are available online at ITB Journals and indexed by <a href=";origin=recordpage">Scopus</a>, <a href=";ISSN=2337-5760">Web of Science (Emerging Sources Citation Index) - Clarivate Analytics</a>, <a href=";tip=sid&amp;clean=0">Scimago JR</a>, <a href="">Directory of Open Access Journals (DOAJ)</a>, <a href=";user=xdqQsgUAAAAJ&amp;view_op=list_works&amp;sortby=pubdate">Google Scholar</a>, <a href=",p24780956,3.html">Index Copernicus</a>, <a href=";colors=7&amp;lang=en&amp;jq_type1=QS&amp;jq_term1=journal+of+mathematical+and+fundamental+sciences">The Elektronische Zeitschriftenbibliothek (EZB) by University Library of Regensburg</a>, <a href=";Find=Journal+of+Mathematical+fundamental+Sciences&amp;GetResourcesBy=QuickSearch&amp;resourceTypeName=allTitles&amp;resourceType=&amp;radioButtonChanged=">EBSCO Open Science Directory</a>, <a href="">ASEAN Citation Index</a>, <a href="">Garba Rujukan Digital (Garuda)</a> and <a href="">Science and Technology Index (SINTA)</a>.</p> <p style="text-align: justify;">The journal has been also accredited for five years based on The Decree of Directorate General of Research and Development Strengthening, Ministry of Research, Technology and Higher Education of the Republic of Indonesia <a href="">No. 030/E/KPT/2018</a>, dated on October 24th, 2018.</p> <p style="text-align: justify;">Published by Institute for Research and Community Services, Institut Teknologi Bandung, in collaboration with <a href="">Indonesian Chemical Society (Himpunan Kimia Indonesia - HKI)</a>.</p> <p>ISSN: <a href="">2337-5760</a>; E-ISSN: <a href="">2338-5510</a></p> <p><strong><u>Publication History</u></strong></p> <p><strong>Formerly known as:</strong></p> <ul> <li>ITB Journal of Science (2008 - 2012)</li> <li>Proceedings ITB Science and Technology (2003 - 2007)</li> <li>Proceedings ITB (1961 - 2002)</li> </ul> <p>Back issues also can be read online at <a href=""></a></p> <p><a title="SCImago Journal &amp; Country Rank" href=";tip=sid&amp;exact=no"><img src=";title=true" alt="SCImago Journal &amp; Country Rank" border="0" /></a></p> Institute for Research and Community Services (LPPM) ITB en-US Journal of Mathematical and Fundamental Sciences 2337-5760 Designing Aquifer Model for the Banks of the Serayu River, Sokawera, Somagede, Banyumas, Indonesia by Means of 1D-Electrical Resistivity Data <p>A geoelectric survey using the 1D-electrical resistivity method was applied to design a groundwater aquifer model for the banks of the Serayu River in Sokawera Village, Somagede District, Banyumas Regency, Indonesia. The aim of this research was to identify the characteristics of aquifers in the research area based on resistivity log data. Acquisition, modeling, and interpretation of resistivity data were carried out and the results were lithological logs at seven sounding points. Correlation between the lithological logs resulted in a hydrostratigraphic model. This model is composed of several hydrological units, i.e. shallow aquifer, aquitard, and deep aquifer. The shallow aquifers are composed of sandy clay (10.81-18.21 Wm) and clayey sand (3.04-7.43 Wm) with a depth of groundwater from the water table to 27.51 m. The deep aquifers are composed of sandstone with variation of porosity (2.24-12.04 Wm) at a depth of more than 54.98 m. Based on this model, potential shallow aquifers were estimated to be at sounding points Sch-5, Sch-6, and Sch-7. This hydrostratigraphic model shows that the two types of aquifers are separated by an aquitard layer, allowing groundwater infiltration from the shallow aquifer to the deep aquifer and vice versa. Moreover, the Serayu riverbanks in this research area are estimated to be a groundwater discharge area.</p> Sehah Hartono Zaroh Irayani Urip Nurwijayanto Prabowo Copyright (c) 2021 Journal of Mathematical and Fundamental Sciences 2021-12-03 2021-12-03 53 3 344 357 10.5614/ Purely Data-driven Exploration of COVID-19 Pandemic After Three Months of the Outbreak <p>Many research studies have been carried out to understand the epidemiological characteristics of the COVID-19 pandemic in its early phase. The current study is yet another contribution to better understand the disease properties by parameter estimation based on mathematical SIR epidemic modeling. The authors used Johns Hopkins University’s dataset to estimate the basic reproduction number of COVID-19 for five representative countries (Japan, Germany, Italy, France, and the Netherlands) that were selected using cluster analysis. As byproducts, the authors estimated the transmission, recovery, and death rates for each selected country and carried out statistical tests to see if there were any significant differences.</p> Shirali Kadyrov Alibek Orynbassar Hayot Berk Saydaliev Copyright (c) 2021 Journal of Mathematical and Fundamental Sciences 2021-12-03 2021-12-03 53 3 358 368 10.5614/ Slater-Pauling-like Behavior of Spin Hall Conductivity in Pt-based Superlattices <p>The intrinsic spin Hall effect in the bulk systems of late transition metals (Os, Ir, Pt, and Au) as well as the Pt-based superlattices were investigated by using first-principle calculations. By comparing the computed spin Hall conductivities of Pt−M superlattices (M=Os, Ir, and Au) with different compositions and those obtained from atomic bulk composition, we saw that the spin Hall conductivities (SHCs) follow the behavior described by the Slater-Pauling curve, the maximum of which is at pure Pt bulk. From the examination of the band structures of the considered systems, we found that the origin of this behavior comes from the variation of the band structures as a direct consequence of the change of the number of electrons and hybridization effects.</p> Abdul-Muizz Pradipto Kohji Nakamura Copyright (c) 2021 Journal of Mathematical and Fundamental Sciences 2021-12-03 2021-12-03 53 3 369 379 10.5614/ Optimal Control in a Mathematical Model of Smoking <p>This paper presents a dynamic model of smoking with optimal control. The mathematical model is divided into 5 sub-classes, namely, non-smokers, occasional smokers, active smokers, individuals who have temporarily stopped smoking, and individuals who have stopped smoking permanently. Four optimal controls, i.e., anti-smoking education campaign, anti-smoking gum, anti-nicotine drug, and government prohibition of smoking in public spaces are considered in the model. The existence of the controls is also presented. The Pontryagin maximum principle (PMP) was used to solve the optimal control problem. The fourth-order Runge-Kutta was employed to gain the numerical solutions.</p> Nur Ilmayasinta Heri Purnawan Copyright (c) 2021 Journal of Mathematical and Fundamental Sciences 2021-12-03 2021-12-03 53 3 380 394 10.5614/