cover
Article Per Year (5 Year)
All
Home Page
OAI Link
Editorial Team
Contact
Reviewer
Google Scholar
Contact Name
Dwi Sulisworo
Contact Email
sulisworo@iistr.org
Phone
+6281328387777
Journal Mail Official
esl@journal.iistr.org
Editorial Address
Jalan Sugeng Jeroni No. 36 Yogyakarta 55142, Indonesia
Location
Kota yogyakarta,
Daerah istimewa yogyakarta
INDONESIA
Engineering Science Letter
Published by Indonesian Institute of Science and Technology Research
ISSN : 29618924     EISSN : 2961872X     DOI : https://doi.org/10.56741/esl.v1i02
Core Subject : Science, Engineering,
Computer Science & IT Control & Systems Engineering Engineering Industrial & Manufacturing Engineering Materials Science & Nanotechnology
Engineering Science Letter is an international peer-reviewed letter that welcomes short original research submissions on any branch of engineering, computer science, and technology, as well as their applications in industry, education, health, business, and other fields. Artificial intelligence, image processing, data mining, data science, bioinformatics, computational statistics, electrical engineering, electronics engineering, telecommunications, hardware systems, industrial automation, industrial engineering, fluids and physics engineering, mechanical engineering, chemical engineering, and their applications are among the engineering and computer science topics covered by the journal. All papers submitted will go through a peer-review process to ensure their quality. Submissions must contain original research and contributions to their field. The manuscript must adhere to the author’s guidelines and have never been published before.
Arjuna Subject : Teknik (semua kategori) - Teknik (Lain-Lain)
Articles 79 Documents
 4   5   6   7   8 
Forecasting Rice Price Volatility Utilizing BiLSTM-SHAP to Ensure National Food Stability Manurung, Juliana Damayanti; Sikana, Nadya; Simamora, Fandi Presly; Manurung, Zoni Zikro
Engineering Science Letter Vol. 4 No. 03 (2025): Engineering Science Letter
Publisher : The Indonesian Institute of Science and Technology Research

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.56741/IISTR.esl.001360

Abstract

Rice price volatility in Indonesia remains a persistent economic issue, partly driven by climate variability and fluctuations in national rice production, prompting the government to resort to substantial annual imports. However, the extent to which domestic production factors and weather conditions influence future rice prices has not been quantitatively evaluated. This study aims to forecast short-term rice prices in Indonesia by integrating multiple time-series features, including rice prices, harvested area, paddy production, and weather features, using a Bidirectional Long Short-Term Memory (BiLSTM) network. Daily data from 2013 to 2024 were collected from the National Statistics Agency, Food Price Panel, and the Meteorology and Climatology Agency. Chronological split was applied for training, validation, and testing to preserve temporal dependency. The optimal model predicts rice prices seven days ahead using 256 hidden units, achieving MAE of 128.84 IDR, RMSE of 157.98 IDR, and R² of 0.694. SHAP analysis shows that historical rice prices have the strongest contribution with a SHAP value of 0.969652, significantly higher compared to other features. The results demonstrate that integrating agricultural and climatic inputs improves predictive performance while providing interpretable insights into price-forming factors.
Simulation of Updraft and Downdraft Gasification Using Computational Fluid Dynamics (CFD) for Production of Hydrogen-Rich Syngas from Cow Manure Waste Utami, Amaliyah Rohsari Indah; Salma, Anindya Nabila; Muchtar, Daffa Rayhan Betha; Sintawardani, Neni; Suwandi
Engineering Science Letter Vol. 4 No. 03 (2025): Engineering Science Letter
Publisher : The Indonesian Institute of Science and Technology Research

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.56741/IISTR.esl.001397

Abstract

Biomass gasification offers a promising route to low‑carbon hydrogen, yet the operating conditions and reactor configuration governing hydrogen-rich syngas remain insufficiently compared across practical regimes. This study aims to quantify the effects of gasifier type (updraft vs. downdraft), operating temperature, and superficial velocity on hydrogen production performance, with emphasis on the syngas H2/CO ratio. Computational fluid dynamics simulations were implemented to model devolatilization, oxidation, and reduction pathways under steady-state assumptions, while systematically varying temperature (680-800°C) and air superficial velocity (0.0025-4 m/s). Model validation against experimental reference data demonstrated good agreement, with relative errors ranging from 5.95% to 6.93%. The results indicate that a downdraft configuration operated at 680°C and 2 m/s maximizes the H2/CO ratio, achieving a value of 2.091, outperforming alternative settings in terms of hydrogen yield and energy efficiency, albeit with higher variability than the updraft configuration. Increasing air flow beyond this optimum diminishes the H2/CO ratio due to enhanced oxidation, whereas raising the temperature to 800°C generally reduces the average H2/CO across both configurations. These findings establish a practical operating window for hydrogen‑rich syngas from livestock waste and highlight the need for rigorous process control to manage variability in downdraft operation. The study provides evidence-based guidance for gasifier design and operation, aiming to achieve efficient and renewable hydrogen production.
Analysis of the Effect of Damdex Addition to Concrete Mixture on Compressive Strength Sari, Endah Murtiana; Probokusumo; Rokhmah, Alfiya; Ashidqi, Muhamad Dzaky; Rahmat; Junaedi, Thomas
Engineering Science Letter Vol. 4 No. 03 (2025): Engineering Science Letter
Publisher : The Indonesian Institute of Science and Technology Research

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.56741/IISTR.esl.001420

Abstract

This study aims to determine the compressive strength and modulus of elasticity of concrete with the addition of Damdex variables to obtain the best composition. This research method is classified as quantitative research conducted at PT. Fresh Beton Indonesia Batching Plan BSD. In this study, research was conducted using two different concrete mixtures, namely 1 Pc: 2 S: 3 Gr and 1 Pc: 3 S: 2 Gr, each of which was supplemented with Damdex at concentrations of 0.0%, 0.2%, 0.4%, and 0.6%. According to the study's results, the highest compressive strength and modulus of elasticity were achieved in a concrete mixture of 1 Pc: 2 S: 3 Gr, with a variable addition of Damdex at 0.2%, resulting in a compressive strength of Fc 15.11 MPa and a modulus of elasticity of 18975.061 MPa. Meanwhile, the lowest compressive strength and modulus of elasticity results were obtained in the concrete mixture of 1 Pc: 2 S: 3 Gr with the variable addition of Damdex 0.6%, with a compressive strength of Fc 12.90 MPa and a modulus of elasticity of 17049.89 MPa. In the concrete mixture of 1 Pc: 3 S: 2 Gr, the compressive strength and modulus of elasticity were smaller compared to the concrete mixture of 1 Pc: 2 S: 3 Gr, with the highest results in the variable addition of Damdex 0.2%, with a compressive strength of Fc 9.89 MPa and a modulus of elasticity of 13846.477 MPa. Compressive strength and elastic modulus were measured at 28 days in accordance with SNI 1974:1990/2847 procedures. Among the tested mixtures, the 0.20% Damdex addition achieved the highest average compressive strength and elastic modulus. Within the tested conditions, 0.20% Damdex provided the best average performance; however, further work with larger samples and additional durability metrics is needed to confirm this trend.
A Fuzzy Logic Approach for Temperature Stability in Infant Incubator Systems Syaifudin; Kholiq, Abd.; Maghfiroh, Anita Miftahul
Engineering Science Letter Vol. 4 No. 03 (2025): Engineering Science Letter
Publisher : The Indonesian Institute of Science and Technology Research

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.56741/IISTR.esl.001451

Abstract

An infant incubator is a critical life-support device that provides thermal regulation for premature or low-birth-weight infants who are unable to maintain stable body temperature. Precise temperature control is essential, as instability and prolonged transient responses can increase health risks. Conventional on-off control methods commonly used in basic incubator systems often result in slower stabilization and higher temperature error. Therefore, this study aims to design and implement a baby incubator temperature control system using a fuzzy logic controller (FLC) integrated with a DS18B20 temperature sensor to improve thermal stability. The proposed system was implemented on a physical incubator prototype and evaluated experimentally. System performance was assessed based on dynamic response characteristics, including rise time, peak overshoot, and settling time. Experiments were conducted using three temperature setpoints: 32°C, 35°C, and 36°C. To ensure measurement accuracy, system performance was validated using an Incu Analyzer as a reference device. The experimental results show that the fuzzy logic-based control system achieved a steady-state temperature error of approximately 1% across all setpoints. The maximum observed settling time after peak overshoot was 100 seconds, indicating faster and more stable temperature regulation compared with conventional on-off control methods reported in previous studies. These results demonstrate that fuzzy logic control is effective in handling nonlinear thermal dynamics and improving temperature stability in infant incubator systems. This study focuses on technical performance evaluation; therefore, further investigations related to safety assessment and regulatory compliance are required before clinical implementation. Nevertheless, the proposed system shows strong potential as an intelligent temperature control approach for the development of neonatal incubator technology.
Modelling Optimisation of Distributed PV-Battery Charge and Discharge Modes Using Systems for Improved Sustainable Energy Management Baqaruzi, Syamsyarief; Mustaqim, Amrina; Muhtar, Ali; Rizky Hikmatullah, Muhammad; Fadhilah, Rahmat; Munandar, Andika; Kharisma Army, Edo; Wira Buana, Setiadi; Wahyudi, Rizqi; Rifqi Dwi S, Muhammad
Engineering Science Letter Vol. 5 No. 01 (2026): In Press - Engineering Science Letter
Publisher : The Indonesian Institute of Science and Technology Research

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.56741/IISTR.esl.001508

Abstract

This study examines the simulation of charge and discharge modes of lithium-ion batteries in a distributed photovoltaic system using MATLAB/ Simulink modeling. The objective is to analyze the integration of solar panels with battery-based energy storage systems to optimize performance and efficiency. The methodology involves mathematical modeling of photovoltaic cells based on p-n junctions, with key parameters such as temperature (15–30°C) and irradiance (1000 W/m²), along with the design of a Solar Charge Controller (SCC) to regulate energy flow. Simulations were conducted on four 150 W photovoltaic panels under varying environmental conditions, integrated with parallel-connected 12 V 250 Ah batteries. Results show a system efficiency of 87% at 25°C and 1000 W/m² irradiance, with panel output voltages aligning with mathematical equations (0.15 A error). Discharge mode analysis, accounting for system losses (inverter 5%, SCC 3%, wiring 2%), confirms the battery can supply a 5 Ω load for approximately 2.00 hours at 45% State of Charge (SOC), representing a 9.5% reduction from the ideal calculation. Simulations also compare SCC performance using DC and photovoltaic sources, demonstrating consistency in energy flow regulation. Validation results indicate the Simulink model’s accuracy in representing real-world characteristics, though MATLAB code simulations exhibit higher precision. The study highlights the importance of SCC control and SOC management to enhance battery lifespan and stability in renewable hybrid energy systems. Implications include potential applications.
Performance Evaluation of Machine Learning Algorithms for Supply Chain Data Classification Maniah
Engineering Science Letter Vol. 5 No. 01 (2026): In Press - Engineering Science Letter
Publisher : The Indonesian Institute of Science and Technology Research

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.56741/IISTR.esl.001524

Abstract

Forecasting systems that are data-driven are of great importance in streamlining industrial and business processes during the digital transformation age. Supply chain management (SCM) is among the most significant processes for enhancing operational efficiency and supporting strategic decision-making. This study seeks to evaluate the performance of two machine learning-based classification algorithms, namely Naive Bayes and the k-Nearest Neighbours (K-NN) algorithm, using data in the supply chain. Some of the most valuable operational attributes, including payment method, customer segment, shipment status, profit per transaction, and customer location, are stored in the database. The data were first cleaned and then normalised and label-encoded, after which they were split into training and test sets with a ratio of 80:20. The performance of the two algorithms was assessed using accuracy, precision, recall, and F1-score. The findings of the research indicate that Naive Bayes is the most promising algorithm; its accuracy and precision are 99.75%, and its recall rate is close to 100% in the majority of the classes. These findings show that Naive Bayes is a probabilistic algorithm that better fits the data distribution than a distance-based K-NN algorithm.
Impact of Sustainable Drainage with Porous Asphalt to Reduce Urban Flood Risk in Vulnerable Residential Areas Sriwati, Meny
Engineering Science Letter Vol. 5 No. 01 (2026): In Press - Engineering Science Letter
Publisher : The Indonesian Institute of Science and Technology Research

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.56741/IISTR.esl.001551

Abstract

Climate change and rapid urbanization in Makassar have increased the frequency of heavy rainfall, causing excessive runoff and flooding in densely populated areas. Conventional drainage systems are no longer able to accommodate the increased water volume, thus creating an urgent need for sustainable engineering solutions. The objectives of this study were to test the effectiveness of porous asphalt in managing stormwater runoff and increasing infiltration, and to develop a sustainable drainage system model that suits the hydrological, technical, and socio-economic conditions of tropical urban areas. The method used was a quantitative experiment with a hydrological and environmental engineering approach. The study sample included twenty field test locations in flood-prone areas of Makassar. Data were collected through field infiltration measurements, SWMM simulations, and laboratory asphalt porosity tests. Analysis was performed using multiple linear regression and hydrological model validation. The results showed that porous asphalt was able to increase infiltration capacity from 210 to 340 mm/hour and reduce surface runoff volume by 40.7 percent. The inundation depth was reduced by half from the initial condition, and the drainage system efficiency increased from an index of 3.2 to 4.3. The correlation coefficient between porosity and infiltration reached 0.79 (p < 0.01), indicating a strong positive relationship. These findings indicate that the application of porous asphalt effectively reduces flood risk while improving environmental quality. In conclusion, porous asphalt is a feasible technical and ecological solution for water runoff management in tropical areas. Therefore, a sustainable drainage system based on porous asphalt can be a strategic component in adaptive urban development to climate change.
Techno-Economic Analysis of Small-Scale Reverse Osmosis Desalination for Likupang Tourism Area Nauli, Maria Anindita; Harwin; Durry, Kezia Rambu
Engineering Science Letter Vol. 5 No. 01 (2026): In Press - Engineering Science Letter
Publisher : The Indonesian Institute of Science and Technology Research

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.56741/IISTR.esl.001698

Abstract

Likupang, a Super Priority Tourism Destination in Indonesia, faces significant challenges in securing a reliable and affordable fresh water supply, currently depending on expensive trucked-in water. This study evaluates the techno-economic feasibility of a small-scale Reverse Osmosis (RO) desalination system to address this issue. Using DuPont’s WAVE Water Treatment Design software, three distinct operational scenarios (A = 50, B = 80, and C = 90 m³/day capacities) were designed and simulated to accommodate the fluctuating water demand characteristic of a tourism area. The technical analysis identified the 80 m³/day demand-responsive scenario as the most energy-efficient, with a Specific Energy Consumption (SEC) of 3.73 kWh/m³. Meanwhile, the economic evaluation, based on the Levelized Cost of Water (LCOW), determined that the most cost-effective strategy is Scenario A with an LCOW of 60,766 IDR/m³. This cost is significantly lower than the current market price of trucked-in water, demonstrating that small-scale RO desalination is a viable and economically competitive solution to support sustainable tourism development in Likupang.
Analysis of Patterns and Drag of Tandem Minibus Models in Various Configurations Rauf, Wawan; Boli, Rahmad Hidayat; Ishak, Sahional; Talango, Novriyanti
Engineering Science Letter Vol. 5 No. 01 (2026): In Press - Engineering Science Letter
Publisher : The Indonesian Institute of Science and Technology Research

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.56741/IISTR.esl.001961

Abstract

The flow through three mini buses arranged in tandem is one type of fluid flow in infrastructure and transportation engineering. The characteristics of the flow pattern formed in each vehicle have an influence on the flow pattern formed in other vehicles. The purpose of this study is to analyze the drag coefficient and characteristics of the flow pattern in models in various configurations and distances between models. The test was conducted by applying experimental methods and numerical computation to obtain the characteristics of the flow pattern. Specifically to obtain the results of the drag coefficient, the method used was only numerical computation. The results of the study showed that the distance between the M/D models influenced the flow pattern formed in all configurations. The smallest drag coefficient for each configuration 1 Cd = 1.43285 at M/D = 0.03, Configuration 2 Cd = 0.80341 at M/D = 0.01, and configuration 3 Cd = 0.77911 at M/D = 0.03 as well as the model with the lowest drag compared to all distances in configuration 1 and configuration 2.

Page 8 of 8 | Total Record : 79

 4   5   6   7   8 

Filter by Year

2022 2026


Reset
Filter By Issues
All Issue Vol. 5 No. 01 (2026): In Press - Engineering Science Letter Vol. 4 No. 03 (2025): Engineering Science Letter Vol. 4 No. 02 (2025): Engineering Science Letter Vol. 4 No. 01 (2025): Engineering Science Letter Vol. 3 No. 03 (2024): Engineering Science Letter Vol. 3 No. 02 (2024): Engineering Science Letter Vol. 3 No. 01 (2024): Engineering Science Letter Vol. 2 No. 03 (2023): Engineering Science Letter Vol. 2 No. 02 (2023): Engineering Science Letter Vol. 2 No. 01 (2023): Engineering Science Letter Vol. 1 No. 02 (2022): Engineering Science Letter Vol. 1 No. 01 (2022): Engineering Science Letter More Issue