Claim Missing Document
Check
Articles

Found 27 Documents
Search

Investigating Long-Run and Short-Run Dynamics of Palm Oil Production with Key Factors Using the VECM Method Lathifah Zahra; Gustriza Erda
Operations Research: International Conference Series Vol. 6 No. 4 (2025): Operations Research International Conference Series (ORICS), December 2025
Publisher : Indonesian Operations Research Association (IORA)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.47194/orics.v6i4.429

Abstract

This study investigates the long-run and short-run relationships among palm oil production, rainfall, the number of bunches per palm (NOB), and average bunch weight (BTR) using the Vector Error Correction Model (VECM). Monthly data from 2015 to 2024 obtained from PT Perkebunan Nusantara IV (PTPN IV) Regional III, Sei Rokan Estate, were analyzed. Descriptive statistics indicate high variability in rainfall and relatively balanced distributions for production, NOB, and BTR. The Augmented Dickey-Fuller (ADF) test confirmed that all variables became stationary after first differencing, and the Johansen cointegration test identified three cointegrating relationships, suggesting both short-run and long-run linkages among variables. The VECM estimation results reveal positive long-run relationships for palm oil production (ECT = 0,052), rainfall (ECT = 0,090), and NOB (ECT = 0,042), indicating that these variables move toward long-run equilibrium in the same direction. In the short run, previous rainfall significantly affects both current palm oil production and NOB, with coefficients of 0,203 and 0,178, respectively, highlighting the critical role of rainfall fluctuations in influencing short-term productivity and fruit development. Model evaluation using the Root Mean Square Error (RMSE) shows low prediction errors across all variables, with rainfall having the highest RMSE (1,334) and NOB the lowest (0,962), confirming the model’s strong predictive performance. Overall, the findings demonstrate that the VECM approach effectively captures both long-run equilibrium and short-run dynamics among key determinants of palm oil productivity in the Sei Rokan plantation.
Palm Oil Production Forecasting Using the SARIMA Model at the Terantam Plantation of PTPN IV Regional III in 2025 Eky; Erda, Gustriza
Operations Research: International Conference Series Vol. 6 No. 4 (2025): Operations Research International Conference Series (ORICS), December 2025
Publisher : Indonesian Operations Research Association (IORA)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.47194/orics.v6i4.430

Abstract

Palm oil is one of the important plantation commodities that plays a major role in the Indonesian economy because it contributes to state revenues, making palm oil production crucial. Forecasting palm oil production is essential to support effective planning and decision-making in plantation management. This study aims to forecast palm oil production at the Terantam Plantation of PTPN IV Regional III for the year 2025 using the Seasonal Autoregressive Integrated Moving Average (SARIMA) model. The data used consist of monthly production data based on volume (kg) from January 2014 to December 2024. The results of the analysis indicate that the best model obtained is SARIMA(0,1,4)(0,1,1)12 with the smallest Akaike Information Criterion (AIC) value. Diagnostic tests show that the model residuals behave as white noise and are normally distributed, indicating that the model is suitable for forecasting. The Mean Absolute Percentage Error (MAPE) value of 8.02% indicates a very good level of accuracy. The forecasting results reveal a seasonal pattern in palm oil production, with the highest production in September 2025 amounting to 15,108,145 kg, and the lowest in February 2025 at 9,347,573 kg. Overall, the SARIMA model is able to capture both trend and seasonal patterns effectively, making the forecast results useful as a reference for production planning and operational management at the Terantam Plantation. Furthermore, the findings of this study are expected to serve as a reference for applying similar forecasting methods to other plantation commodities.
Modeling Cointegrated Nonstationary Air Pollution Data: A Forecasting Study of NO₂ and SO₂ in Indonesia (1950–2022) Adnan, Arisman; Erda, Gustriza; Wamiliana; Russel, Edwin
Science and Technology Indonesia Vol. 11 No. 1 (2026): January
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26554/sti.2026.11.1.161-173

Abstract

 Air pollution from nitrogen dioxide (NO2) and sulfur dioxide (SO2) poses serious threats to human respiratory health and contributes to environmental degradation through acid rain formation. In Indonesia, despite rapid industrialization and increasing emissions, studies examining the interrelated dynamics between NO2 and SO2 at the national level remain limited, with most research focusing only on provincial areas and short time periods. This study fills this gap by analyzing the dynamic relationship between NO2 and SO2 using comprehensive national-level time series data from 1950 to 2022. The analysis examines short-term adjustments, long-term equilibrium patterns, directional causality, and shock responses between the two pollutants. The analysis focuses on identifying the best statistical model to capture the interaction between the two variables. Granger causality tests, impulse response functions (IRFs), and forecast error variance decomposition are applied to examine causal links and response dynamics. The data exhibits nonstationary but cointegrated with rank r=1, indicating a long-run equilibrium correlation between two pollutants. Consequently, the Vector Error Correction Model, VECM(4), is selected as the most appropriate model. The study also provides 10-year forecasts for both pollutants insights into potential future air pollution trends in Indonesia, with NO2 rising from 5.29 to 8.09 million tons and SO2 from3.38 to 5.10 million tons, underscoring the urgent need for integrated emission control policies that address both pollutants simultaneously rather than in isolation.
Empowering the Community of Kubangsari Village, Cilegon City, through Innovation in Processing Corn into Corn Syrup as an Effort to Increase Local Economic Income Sholihin, Miftahus; Sari, Putri Dina; Abdullah, Syarif; Wicaksono, Agung Satrio; Erda, Gustriza; Rivai, Muklas; Anwaar Al'Fathoni, Muhammad Khoirul; Lidyasari, Nadia Bintang
Journal of Community Service in Science and Engineering (JoCSE) Vol 5, No 1 (2026): Available Online in April 2026
Publisher : Faculty of Engineering, Universitas Sultan Ageng Tirtayasa

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.62870/jocse.v5i1.39911

Abstract

The majority of the community in Kubangsari Village, Cilegon City, are farmers and factory workers, with approximately 20% of the population directly dependent on the corn farming sector. Traditionally, corn harvests have been sold raw at prices around IDR 8,000, leaving farmers vulnerable to economic fluctuations, particularly during the rainy season when fields are prone to flooding. This community service program aims to empower the Kubang Lestari Women Farmers Group (KWT) through the innovation of processing purple corn into a functional health beverage named JAJANTAN (Jahe Jagung Anti Oksidan/Ginger Corn Antioxidant). The implementation method spanned one month, involving field surveys, direct production workshops, and assistance in packaging and halal certification. The results demonstrated a significant increase in the added value of agricultural commodities; raw corn was transformed into a ready-to-sell bottled beverage priced at IDR 10,000 per unit, with a production cost of IDR 7,000. This mentorship has successfully increased public knowledge regarding food product diversification and opened opportunities for the development of local Micro, Small, and Medium Enterprises (MSMEs), with full support from the local village government.
Analysis of the Spatial Distribution Pattern of Poverty Percentage in Central Java in 2024 Using the Spatial Autocorrelation Approach Miftahus Sholihin; Gustriza Erda; Putri Dina Sari; Agung Satrio Wicaksono; Atia Sonda; Muhammad Fabian Reinhard Delano; Syukron Faiz
Theta: Journal of Statistics Vol 1, No 1 (2025): Available Online in March 2025
Publisher : Faculty of Engineering, Univesitas Sultan Ageng Tirtayasa

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.62870/tjs.v1i1.31320

Abstract

Poverty remains a critical socio-economic issue in Central Java, Indonesia, exhibiting significant regional disparities. This study aims to analyze the spatial distribution pattern of poverty rates in Central Java in 2024 using a spatial autocorrelation approach with an inverse distance weight matrix. Secondary data from the Central Bureau of Statistics (BPS) of Central Java is utilized, covering poverty percentages across regencies and cities. The analysis method involves Moran’s I to assess global spatial autocorrelation and Local Indicators of Spatial Association (LISA) to identify local spatial clusters. The findings indicate a positive Moran’s I value, suggesting a significant spatial dependence in poverty distribution. Several high-poverty clusters are identified in specific regions, confirming spatial concentration patterns. The study highlights that regional proximity influences poverty rates, where areas with high poverty tend to be surrounded by regions with similar conditions. These results provide empirical evidence for policymakers to design targeted poverty alleviation programs based on spatial characteristics. The study concludes that understanding spatial autocorrelation in poverty distribution is crucial for formulating effective regional development policies and reducing socio-economic disparities.
Forecasting Fire Hotspots in Indonesia: A Comparative Performance Analysis of SARIMA and Pulse Intervention Models Bustami Bustami; Gustriza Erda; Putri Soraya Tampubolon
Jambura Journal of Probability and Statistics Vol 7, No 1 (2026): Jambura Journal of Probability and Statistics
Publisher : Department of Mathematics, Universitas Negeri Gorontalo

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.37905/jjps.v7i1.38133

Abstract

Wildfires in Indonesia have a widespread impact on health, the environment, society, and the economy. The number of hotspots, detected through satellite imagery, is a key indicator in monitoring the severity of fires. Because hotspot data is seasonal and prone to spikes due to extraordinary events such as El Niño, an adaptive forecasting method is needed. The SARIMA model is effective for capturing seasonal patterns, but it is less responsive to extreme spikes. Therefore, intervention analysis with pulse functions is used as an alternative to model sudden and temporary changes in time series data. This study aims to compare the performance of the SARIMA model and an intervention model using a pulse function in forecasting the number of hotspots in Indonesia. The data used in this study were obtained from the Ministry of Environment and Forestry through the SiPongi platform, consisting of monthly data from January 2014 to December 2022. The modeling results show that the SARIMA   model produced  a MAPE value of 36.93%, an RMSE of 66.27, and an MAE of 47.83. In contrast, the intervention model with a pulse function at order b=0, s=0, and r=1 specifically SARIMAachieved  a MAPE of 8.06%, an RMSE of 8.45, and an MAE of 6.67, substantially outperforming the SARIMA model across all metrics. These findings indicate that the intervention model provides much more accurate forecasts of hotspot occurrences in Indonesia. Furthermore, forecasts up to 2025 indicate a declining trend in the number of hotspots over time. However, seasonal patterns remain evident, with expected increases in hotspot activity during the months of February, August, and October. These results are expected to contribute valuable insights for developing more effective forest fire mitigation strategies in Indonesia  
EFEKTIVITAS MEDIA STATAK DIGITAL DALAM MENINGKATKAN HASIL BELAJAR MATEMATIKA SISWA SDN 02 SELAT PANJANG Susilawati Susilawati; Gustriza Erda; Ihda Hasbiyati; Musraini M; Efni Agustiarni; Haposan Sirait Bustami; Fadhila Rahman
Unri Conference Series: Community Engagement Vol 7 (2025): Seminar Nasional Pemberdayaan Masyarakat
Publisher : Lembaga Penelitian dan Pengabdian kepada Masyarakat Universitas Riau

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31258/unricsce.7.643-651

Abstract

Mathematics learning in elementary schools is often considered abstract, difficult to understand, and uninteresting for students. On the other hand, traditional games such as Statak have the potential to be a fun, contextual learning medium. Digitizing this traditional game is seen as a solution to increase student interest and learning outcomes. This study aims to determine the effectiveness of digital Statak media in improving mathematics learning outcomes of fourth-sixth grade students at SDN 02 Selat Panjang. This study used a quasi-experimental approach with a one-group pretest-posttest design. The subjects were 26 fourth-sixth grade students. The instruments used consisted of a mathematics learning achievement test and a student response questionnaire. Data were analyzed using paired t-tests and descriptive analysis. The average pretest score was 77.5, while the average posttest score increased to 87. The t-test results showed a significant difference (p < 0.05) between the pretest and posttest scores. Digital Statak media has proven effective in improving mathematics learning outcomes for students at SDN 02 Selat Panjang. Furthermore, this media fosters learning motivation and plays a role in preserving local culture through the digitization of traditional games.