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All Journal BAREKENG: Jurnal Ilmu Matematika dan Terapan JTAM (Jurnal Teori dan Aplikasi Matematika) Jurnal Layanan Masyarakat (Journal of Public Service) Jurnal Statistika dan Komputasi (STATKOM)
Oktavia, Sabrina Salsa
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Humanities Computer Science & IT Control & Systems Engineering Decision Sciences, Operations Research & Management Economics, Econometrics & Finance Energy Engineering Environmental Science Industrial & Manufacturing Engineering Mathematics Mechanical Engineering Physics Social Sciences Transportation Other

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MODELING AND FORECASTING THE TOTAL VOLUME OF GOODS TRANSPORTED BY RAIL IN INDONESIA USING SEASONAL AUTOREGRESSIVE INTEGRATED MOVING AVERAGE (SARIMA) Syahzaqi, Idrus; Sediono, Sediono; Anggakusuma, Aurellia Calista; Wieldyanisa, Ezha Easyfa; Oktavia, Sabrina Salsa
BAREKENG: Jurnal Ilmu Matematika dan Terapan Vol 19 No 2 (2025): BAREKENG: Journal of Mathematics and Its Application
Publisher : PATTIMURA UNIVERSITY

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30598/barekengvol19iss2pp829-842

Abstract

Transportation has an important role in supporting the mobility of people in Indonesia. Trains are included in the most widely used transportation category because they are effective and efficient, not only transporting passengers, trains also have a role in the distribution of goods. This study aims to model and forecast total volume of goods transported through rail transportation in Indonesia using the Seasonal Autoregressive Integrated Moving Average (SARIMA) Method because the data has seasonal trend. The data used comes from the Central Statistics Agency (BPS) from January 2013 to April 2024. The results were obtained that the SARIMA (0,1,1)(0,1,1)12 model is the best model with a MAPE value of 0.96% which is included in the category of accurate model. In addition to being an additional insight, this research can also be a reference in the management of railway transportation considering the number of uses both passengers, the distribution of goods that continue to increase, and can be recommendation for other research that same topic with it.
Peramalan Jumlah Barang Kereta Api di Indonesia Menggunakan Metode Seasonal Autoregressive Integrated Moving Average (SARIMA) Syahzaqi, Idrus; Sediono, Sediono; Oktavia, Sabrina Salsa; Anggakusuma, Aurellia Calista; Wieldyanisa, Ezha Easyfa
Jurnal Statistika dan Komputasi Vol. 4 No. 1 (2025): Jurnal Statistika dan Komputasi
Publisher : Universitas Nahdlatul Ulama Sunan Giri

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32665/statkom.v4i1.4424

Abstract

Background: Freight transportation is an important part of the business run by PT Kereta Api Indonesia. To support effective strategic planning and infrastructure development, an accurate prediction of the amount of goods to be transported in the future is required. Therefore, historical data-based forecasting methods such as Seasonal Autoregressive Interated Moving Average (SARIMA) can be a relevant approach to predict the number of railway goods in Indonesia. Objective: Obtain a suitable model to forecast the number of goods transported by rail transportation in Indonesia, and to determine the results of the forecasting. Methods: This research uses the time series method with the Seasonal Autoregressive Integrated Moving Averang (SARIMA) model approach based on data characteristics that show seasonal patterns. SARIMA itself is able to integrate seasonal pattern components in the data and is able to effectively capture periodic and structural dynamics in seasonal data. Results: The best model obtained is probabilistic SARIMA(0,1,1)(0,1,1)12, using secondary data sourced from the Central Bureau of Statistics (BPS) in the range of January 2013 to March 2024. Forecasting for the next 12 months (April 2023 to March 2024) shows a Mean Absolute Percentage Error (MAPE) value of 8.03% which indicates that the level of forecasting accuracy is very good. Conclusion: The probabilistic ARIMA(0,1,1)(0,1,1)12 model can be used as a reliable reference in predicting the amount of goods transported through rail transportation in Indonesia.
ANALYSIS OF FACTORS AFFECTING PNEUMONIA IN INDONESIAN TODDLERS USING NONPARAMETRIC REGRESSION WITH LEAST SQUARE SPLINE AND FOURIER SERIES METHODS Saifudin, Toha; Suliyanto, Suliyanto; Nurdin, Nabila; Christiano Ginzel, Bryan Given; Oktavia, Sabrina Salsa; Ariyawan, Jovansha; Ubadah, Mohammad Noufal
BAREKENG: Jurnal Ilmu Matematika dan Terapan Vol 20 No 1 (2026): BAREKENG: Journal of Mathematics and Its Application
Publisher : PATTIMURA UNIVERSITY

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30598/barekengvol20iss1pp0087-0104

Abstract

Pneumonia is the leading cause of death among children under five, with the highest prevalence in Indonesia found in West Papua Province (75%) and the lowest in North Sulawesi (0.3%). This study aims to analyze the factors influencing the prevalence of pneumonia in Indonesian toddlers using nonparametric regression approach by comparing Least Square Spline (LS-Spline) and Fourier Series. Data sourced from the Indonesian Ministry of Health website, consisting of 34 provinces in Indonesia in 2023, with one response variable (Y) and five predictor variables (X). The analyzed factors include the coverage of vitamin A supplementation, malnutrition rates, low birth weight prevalence, measles immunization coverage, and exclusive breastfeeding rates. The analysis was conducted by modeling with nonparametric Least Square Spline regression using up to three optimal knot points, then performing analysis using nonparametric regression with the Fourier series approach. The two methods were compared based on GCV and R², with the best model having lower GCV and higher R². The results showed that LS-Spline was better than Fourier Series, with a GCV value of 233.16 and a coefficient of determination of 92.5%. The findings reveal that the relationships between predictor factors and pneumonia prevalence are nonlinear, with varying influence patterns across different variable ranges. These results indicate that LS-Spline has a strong ability to explain data variability. The Fourier series is limited in this study because it is best suited for periodic data, unlike pneumonia data and its causal factors which do not show such patterns. The weakness of the Fourier Series in this study lies in its suitability for periodic data, while pneumonia cases and their causal factors do not follow such patterns. This study offers insights into health policy making to reduce pneumonia cases, improve their lives, in line with the SDGs target on Good Health and Well-being.
Modelling the Prevalence of Stunting in Toddlers Aged 6 – 23 Months in Indonesia with Approaches Multivariate Adaptive Regression Splines and Generalized Additive Model Aflaha, Nabila Shafa; Oktavia, Sabrina Salsa; Kurniawan, Ardi
JTAM (Jurnal Teori dan Aplikasi Matematika) Vol 10, No 2 (2026): April
Publisher : Universitas Muhammadiyah Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31764/jtam.v10i2.35644

Abstract

Stunting remains a major global public health issue, marked by growth failure caused by long-term nutritional deficiencies in early childhood. In Indonesia, stunting prevalence among children under five was reported at 21.5% in 2023. This study employs an analytical observational approach with a cross-sectional design to examine nutritional factors associated with stunting among children aged 6–23 months in Indonesia, using Multivariate Adaptive Regression Splines (MARS) and Generalized Additive Models (GAM). Secondary data were obtained from the 2024 Indonesian Nutritional Status Survey (SSGI), encompassing 36 provinces. Stunting prevalence was defined as the response variable, while predictor variables included the consumption of animal-source protein, sweetened beverages, unhealthy foods, and the lack of fruit and vegetable intake. The analysis began with descriptive statistics and was followed by MARS and GAM modelling. Model performance was assessed using the coefficient of determination (R²) and Root Mean Square Error (RMSE). The findings indicate that the GAM model outperformed MARS, achieving a higher R² 0.7734 and a lower RMSE 2.5968, compared to MARS with an R² of 0.7319 and an RMSE of 2.8249. While MARS effectively identified structural changes through hinge functions, GAM offered greater modelling flexibility via smooth functions. Among the examined factors, animal-source protein intake showed the strongest association with stunting, followed by the consumption of sweetened beverages and unhealthy foods, whereas inadequate fruit and vegetable intake exhibited a weaker relationship. Overall, both approaches were effective, although GAM demonstrated superior predictive capability for provincial-level stunting analysis.
MOJORAYUNG BISA: ADVANCING FOOD SECURITY THROUGH HOUSEHOLD ORGANIC WASTE UTILIZATION IN MOJORAYUNG VILLAGE, MADIUN Anggriyanto, Nastiti Ivory Putri; Ummam, Muhammad Iqdam Amrul; Witama, I Wayan Dimas Yasa; Jannadra, Kala Kirana; Alfiyanti, Berta Very; Oktavia, Sabrina Salsa; Permatasari, Senja; Tsabitah, Alvina; Fitria, S.Gz, M.Sc, Anisa Lailatul
Jurnal Layanan Masyarakat (Journal of Public Services) Vol. 10 No. 1 (2026): JURNAL LAYANAN MASYARAKAT
Publisher : Universitas Airlangga

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Abstract

Household organic waste management and yard utilization in Mojorayung Village, Wungu District, Madiun Regency have not been optimally implemented, indicating the need for a practical household-based empowerment model. This study aims to improve community knowledge and skills in managing organic waste and utilizing household yards productively through the Mojorayung BISA program. The activities were conducted in July 2025 using a participatory action-based approach consisting of preparation, education, implementation, monitoring–evaluation, and initial replication stages. Program evaluation was carried out by measuring compost technical parameters and administering pre-tests and post-tests to 30 participants. The results showed an increase in the average score from 75.0 to 83.7 (an increase of 8.7 points), indicating improved understanding of organic waste management and yard utilization. The implementation of the Takakura composting method using approximately 9 kg of organic waste produced about 5.4 kg of mature compost within ±3 weeks, characterized by a temperature decrease from 36–40°C to 26°C and a pH increase from 3.5 to 7. The compost produced was utilized for tomato and chili cultivation and supported the production of organic pesticide made from lemongrass. These findings indicate that the integrated household-level circular model is technically feasible, participatory, and potentially replicable in communities with similar socio-environmental characteristics.
Co-Authors Aflaha, Nabila Shafa Alfiyanti, Berta Very Anggakusuma, Aurellia Calista Anggriyanto, Nastiti Ivory Putri Ardi Kurniawan Ariyawan, Jovansha Christiano Ginzel, Bryan Given Fitria, S.Gz, M.Sc, Anisa Lailatul Idrus Syahzaqi Jannadra, Kala Kirana Nurdin, Nabila Permatasari, Senja Sediono, Sediono Suliyanto Suliyanto Toha Saifudin Tsabitah, Alvina Ubadah, Mohammad Noufal Ummam, Muhammad Iqdam Amrul Wieldyanisa, Ezha Easyfa Witama, I Wayan Dimas Yasa