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All Journal JURNAL MATEMATIKA STATISTIKA DAN KOMPUTASI GRADIEN Edumatsains Panrita Abdi - Jurnal Pengabdian pada Masyarakat BAREKENG: Jurnal Ilmu Matematika dan Terapan JURNAL PENGABDI JMM (Jurnal Masyarakat Mandiri) JTAM (Jurnal Teori dan Aplikasi Matematika) Teorema: Teori dan Riset Matematika Jurnal Pengabdian Masyarakat Bumi Raflesia Sainstek : Jurnal Sains dan Teknologi Jurnal Berdaya Mandiri LOSARI: Jurnal Pengabdian Kepada Masyarakat Jurnal Pengabdian kepada Masyarakat TRIBUTE: JOURNAL OF COMMUNITY SERVICES Mathematical Journal of Modelling and Forecasting Jurnal Integritas Serasan Sekundang Indonesian Journal of Statistics and Its Applications
Siska Yosmar
Department Of Mathematics, Faculty Of Mathematics And Natural Sciences, Bengkulu University, Indonesia
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The Probability Model of Earthquake Frequency in the Enggano Segment using Poisson Mixture Models Yosmar, Siska; Rachmawati, Ramya; Damayanti, Septri; Rizal, Jose
JTAM (Jurnal Teori dan Aplikasi Matematika) Vol 10, No 1 (2026): January
Publisher : Universitas Muhammadiyah Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31764/jtam.v10i1.33446

Abstract

An earthquake is a natural disaster that occurs suddenly resulting in numerous casualties, such as loss of life and property. Bengkulu Province is among the provinces affected by severe earthquakes. Studies on probability models for the frequency of earthquake events in Bengkulu Province are still scarce, as outlined in the 2017 book “Map of Sources and Hazards of Indonesian Earthquakes.” This research uses Poisson mixture models to build a probability model for the frequency of earthquake events in the Enggano segment, located in the coastal area of Bengkulu Province.   ..   The phases of model building are the model diagnosis phase, testing the dispersion state relative to the Poisson distribution, testing the dependence of research data on time variables using the Ljung-Box test, and testing the criteria for selecting the best model using the Bayesian Tests Measures of Information Criterion (BIC) and Akaike Information Criterion (AIC). Annual earthquake frequency data from January 1, 1971, to December 31, 2022, were retrieved from the USGS catalog of data on the frequency of major earthquakes with a magnitude of Mw ≥ 4.40, which occurred a total of 633 times. After completing the model building phase, the AIC and BIC values for each model were determined by determining the number of unobserved groups. Both Poisson mixture models and Poisson hidden Markov models produced the same number of unobserved groups of 3 groups with AIC=302.91 and BIC=324.38.
Using Ant Colony Optimization to Solve a Vehicle Routing Problem: Waste Transportation Routes in Bengkulu City Case Study Ramya Rachmawati; Siska Yosmar
EduMatSains : Jurnal Pendidikan, Matematika dan Sains Vol 9 No 2 (2025): January
Publisher : Fakultas Keguruan dan Ilmu Pendidikan, Universitas Kristen Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33541/edumatsains.v9i2.6635

Abstract

The waste problem is one of the serious problems faced by every city in Indonesia, including Bengkulu City. To overcome the problem of waste production which continues to increase every day, the government's role is needed in efforts to transport waste with various facilities and support from the surrounding community. One effort to solve the problem of waste piling up in Temporary Disposal Sites (TPS) is to schedule effective transportation to Final Disposal Sites (TPA). To do the scheduling, one possible approach is a mathematical approach. The purpose of this research is to build a Vehicle Routing Problem (VRP) model using Ant Colony Optimization (ACO), and determine the solution of this model to determine the optimal solution to the problem of transporting waste from all TPS to TPA. This research involved 29 TPS in Bengkulu City. This model is solved using Python 2.7 programming language and PuLP modeller and CPLEX Solver. With 2000 iterations, solutions were found in a relatively short time, which is less than 10 minutes. There are 6 garbage transportation routes in Bengkulu City which are considered as a VRP problem by using ACO which can transport garbage and considering the capacity of garbage trucks. From this route, a total distance of 128 km is obtained.
Markov Chain Model for Daily Rainfall Modeling in Bengkulu City Rachmawati, Ramya; Firdaus; Ratna Widayati; Siska Yosmar; Risfa Fadila; Ajeng Siti Nurul Kharima
EduMatSains : Jurnal Pendidikan, Matematika dan Sains Vol 10 No 4 (2026): April
Publisher : Fakultas Keguruan dan Ilmu Pendidikan, Universitas Kristen Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33541/edumatsains.v10i4.8000

Abstract

Bengkulu City is a region in Indonesia that is particularly vulnerable to shifts in rainfall patterns, which can have significant impacts on the agricultural sector, water resource management, and disaster mitigation. The uncertainty in rainfall patterns often complicates long-term planning. Hence, it is necessary to adopt a statistical approach that can model and predict rainfall characteristics with greater accuracy. This research aims to develop a Markov Chain model to represent the daily rainfall regime in Bengkulu City. The daily rainfall data are categorized into rainfall intensity states, namely: no rain, light, moderate, heavy, or very heavy rainfall. By leveraging historical daily rainfall data, this model is expected to identify the transition probabilities between these states. Based on the obtained steady-state probabilities, it can be concluded that regardless of today’s rainfall condition in Bengkulu City, the long-term probabilities for tomorrow’s weather are as follows: 38% for no rain, 43% for light rain, 13.8% for moderate rain, 4.2% for heavy rain, and 1% for very heavy rain.
OPTIMALISASI PENGGUNAAN PANEL SURYA PADA POMPA AIR UNTUK MENDORONG KEMANDIRIAN PANGAN Yuliza, Elfi; Sipriyadi, Sipriyadi; Daratha, Novalio; Intara, Yazid Ismi; Yosmar, Siska; Irkhos, Irkhos; Yusup, Pajri; Sihombing, Yosia Pandu
JMM (Jurnal Masyarakat Mandiri) Vol 10, No 2 (2026): April
Publisher : Universitas Muhammadiyah Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31764/jmm.v10i2.38441

Abstract

Abstrak: Desa Banjarsari memiliki lahan pertanian yang cukup luas dengan sistem pengairan bersifat tadah hujan. Di sisi lain, disekitar persawahan terdapat sungai yang dapat dimanfaatkan sebagai sumber pengairan, namun dengan posisi lebih rendah . Oleh karena itu, pada kegiatan pengabdian ini dilakukan inovasi sistem pengairan pompa air berbasis energi surya dengan tujuan penyediaan sistem pengairan berbasis energi bersih dan sosilisasi penggunaan sistem. Adapun khalayak sasaran pada kegiatan ini adalah kelompok tani dan perangkat desa yang berjumlah 20 orang. Pelaksanaan pengabdian dibagi menjadi 3 tahap yakni persiapan, pelaksanaan dan evaluasi. Tahap persiapan dilakukan penyiapan sistem di laboratorium dan diskusi pelaksanaan kegiatan dengan mitra. Pelaksanaan kegiatan dimulai dengan pemasangan sistem, sosialisasi dan pelatihan. Sedangkan tahap evaluasi dilakukan melalui kuesioner dan wawancara. Berdasarkan tahapan yang dilakukan, dihasilkan sistem pengairan berbasis pompa panel, peningkatan pengetahuan dan keahlian khalayak. Hasil kuesioner menunjukan peningkatan pengetahuan khalayak tentang pemanfaatan panel surya, dari 80% menjadi 100% setelah pelaksanaan kegiatan.Abstract: Banjarsari Village has extensive farmland irrigated by rainwater. In Additon, a river located below the rice fields offers additional irrigation potential. To optimize this resource, a solar-powered water pump irrigation system was introduced as part of a community service initiative. The project aimed to provide a clean and sustainable irrigation solution while enhancing community awareness and capacity in utilizing renewable energy technology. The program engaged 20 participants, including farmers and village officials. Activities were conducted in three stages: preparation, implementation, and evaluation. During the preparation phase, the system was assembled and tested in the laboratory, followed by coordination meetings with local partners. The implementation phase involved on-site installation, community outreach, and hands-on training for users. The evaluation phase employed questionnaires and interviews to assess outcomes. The project successfully established a functional solar-powered irrigation system and strengthened participants’ knowledge and technical skills. Questionnaire results indicated a significant increase in awareness of solar panel utilization, rising from 80% prior to the program to 100% after its completion.
LQ45 Stock Portfolio Selection using Black-Litterman Model in Pandemic Time Covid-19 Yosmar, Siska; Damayanti, S; Febrika, S
Indonesian Journal of Statistics and Applications Vol 5 No 2 (2021)
Publisher : Statistics and Data Science Program Study, SSMI, IPB University, in collaboration with the Forum Pendidikan Tinggi Statistika Indonesia (FORSTAT) and the Ikatan Statistisi Indonesia (ISI)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29244/ijsa.v5i2p343-354

Abstract

The world was shocked by the emergence of a virus that spread very quickly to several countries including Indonesia at the end of 2019. This virus infection is called Corona Virus Disease 2019 (Covid-19). The outbreak of Covid-19 not only threatens human lives but also disrupts various economic, financial, and business activities, especially in Indonesia. A stock portfolio is a collection of financial assets in a unit that is held or created by an investor, investment company, or financial institution. The Black-Litterman model of the stock portfolio is a portfolio model that involves the CAPM equilibrium return and investor views. The purpose of this study is to determine the stock portfolio with the Black-Litterman model using company data listed in the LQ45 stock index from January 2020 to June 2020. Four of the twenty-nine LQ45 stocks were selected as assets in the stock portfolio. The stock portfolio containing the four stocks, namely ICBP, KLBF, MNCN, and TLKM with the Black-Litterman model resulted in an expected return of 2.07% and a risk of 2.82%.
Co-Authors Acnesya, Vivin Ajeng Siti Nurul Kharima Arita Nurul Khotimah Baki Swita Damayanti, S Daratha, Novalio Dian Agustina Dion Raja Kusumah Dwi Miranda, Anggel Dyah Setyo Rini Elfi Yuliza Etis Sunandi Fajri Ramadan Fanani Haryo Widodo Febrika, S Firdaus Gumaratia, Deriani Herlin Fransiska Hisyam Rahmatullah Akbar Irkhos Irkhos Jose Rizal Kelfin Hardiansyah Lidya Savitri marsela, esti Meca Nerdika Moradarma Taksiyah Nova Asri Ramdhani Nur Afandi Nur Afandi Nur El Hasanah Nurul Hidayati Ramya Rachmawati Ratna Widayati Rewan Jayadi Risfa Fadila S Damayanti S Febrika Septri Damayanti Septri Damayanti SIHOMBING, YOSIA PANDU Sipriyadi Swita, Baki Syahrul Akbar Winalia Agwil Yazid Ismi Intara Yusup, Pajri Zulfia Memi Mayasari