cover
Article Per Year (5 Year)
All
Home Page
OAI Link
Editorial Team
Contact
Reviewer
Google Scholar
Contact Name
Yuliah Qotimah
Contact Email
yuliah@itb.ac.id
Phone
+6281221296669
Journal Mail Official
jets@itb.ac.id
Editorial Address
ITB Journal, Gedung CRCS ITB Lantai 6 Jalan Ganesa No. 10 40132 Bandung - Indonesia
Location
Kota bandung,
Jawa barat
INDONESIA
Journal of Engineering and Technological Sciences
Published by Institut Teknologi Bandung
ISSN : 23385502     EISSN : 23375779     DOI : 10.5614/j.eng.technol.sci
Core Subject : Engineering,
Aerospace Engineering Automotive Engineering Chemical Engineering, Chemistry & Bioengineering Civil Engineering, Building, Construction & Architecture Electrical & Electronics Engineering
ournal of Engineering and Technological Sciences welcomes full research articles in: General Engineering Earth-Surface Processes Materials Science Environmental Science Mechanical Engineering Chemical Engineering Civil and Structural Engineering Authors are invited to submit articles that have not been published previously and are not under consideration elsewhere.
Arjuna Subject : Teknik (semua kategori) - Teknik (Lain-Lain)
Articles 176 Documents
 14   15   16   17   18 
Comparison of PI and PID Controllers for UPQC Integrated Hybrid Renewable Energy System Manpreet Singh; Lakhwinder Singh
Journal of Engineering and Technological Sciences Vol. 58 No. 4 (2026): Vol. 58 No. 4(2026): August
Publisher : Directorate for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2026.58.4.3

Abstract

Unified Power Quality Conditioner (UPQC) plays a key role in improving power quality by alleviating voltage and current troubles in electrical distribution systems. The ability of UPQC to respond effectively to power quality turbulences is essentially determined by its control technique. The proportional-integral (PI) and proportional-integral-derivative (PID) controllers are the two most popular control techniques for UPQC. The primary objective of this article is to present a comparative analysis of UPQC performance using PI and PID controllers. The proposed system integrates a photovoltaic system, wind turbine and battery energy storage with UPQC. The PI and PID controllers are employed to regulate the dynamic response of the system. The comparative analysis of the controllers is done on the basis of qualitative parameters such as current response, voltage stability, fast fourier transform (FFT) analysis, step response and quantitative parameters such as total harmonic distortion, maximum overshoot, settling time, power factor, voltage regulation and DC-link deviation. Qualitatively, PID offers smoother current and voltage responses, stronger damping, better harmonic mitigation, and faster transient recovery. Quantitatively, the PID achieves 48% lower THD, 50% reduction in overshoot, halved settling time, improved power factor (0.99 vs. 0.95), and improved voltage regulation (1.7% vs. 4.2%).
Reading Method and Experimental Evaluation of the UWB System D-DWM-PG3.6 for Local Positioning Thuan-Tien Tran; Quoc-Thanh Tra; Chi-Ngon Nguyen; Phuong-Lan Tran-Nguyen; Quoc-Khanh Huynh
Journal of Engineering and Technological Sciences Vol. 58 No. 4 (2026): Vol. 58 No. 4(2026): August
Publisher : Directorate for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2026.58.4.4

Abstract

The UWB D-DWM-PG3.6 is a standalone positioning system based on Decawave’s (now Qorvo) ultra-wideband technology. It is designed for local positioning without requiring satellite data systems, making it effective in areas with weak or unstable GPS signals. This study focuses on developing a method for reading and filtering data from the UWB system to obtain stable position parameters.  Outlier data are removed, and filtering by moving average helps to smooth and stabilize the position data. Experiments were conducted in a 40×30 m space to evaluate the method’s accuracy. The results show an average positioning error of 7.1 ± 3.6 cm, with a maximum of 26.9 cm under obstructed conditions. These findings highlight the potential for navigation applications in autonomous devices operating in enclosed spaces, such as warehouses and agricultural greenhouses, at a reasonable cost. However, the error magnitude indicates that the system should be integrated with ultrasonic sensors, recognition cameras, or laser technology to improve accuracy.
Influence of NaOH Treatment Duration on the Properties of High-Loaded Coconut Shell Particle Epoxy Biocomposites Ismail Ismail; Mayang Sari; Syarifah Fathmiyah; Fauzi Fauzi; Adi Rahwanto
Journal of Engineering and Technological Sciences Vol. 58 No. 4 (2026): Vol. 58 No. 4(2026): August
Publisher : Directorate for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2026.58.4.5

Abstract

The objective of this work is to study the effect of soaking time of coconut shell particles in 10% NaOH solution on the performance of the biocomposites. The soaking time was varied from 0, 2, 4, 6, and 8 hours. The size of the coconut shell particles used in this study was 200 mesh. The chemical characterization of coconut shell particles before and after treatment with NaOH was performed using FTIR, XRF, and XRD. The coconut shell biocomposites were prepared by using the press method, consisting of 80 vol.% coconut shell particles and 20 vol.% epoxy resin. The density, porosity, water absorption, thickness swelling, modulus of rupture, modulus of elasticity, and thermal decomposition of biocomposites were measured. The results show that the performance of the biocomposites is significantly affected by the immersion time of coconut shell particles in the NaOH solution. Further, it has been observed that the notable improvements in the properties occur after NaOH treatment of the fillers. SEM images showed a significant reduction in particle agglomeration and porosity after NaOH treatment of the fillers. This indicates that the NaOH treatment modified the surface characteristics of the coconut shell particles by removing lignin, which improved their compatibility and interaction with the epoxy resin.
Coolant Bleed Flow Modeling and Prediction for Aircraft Engines Based on TSO-RF Algorithm Enlai Zhang; Jiaqiang Jiang; Zijuan Ren
Journal of Engineering and Technological Sciences Vol. 58 No. 4 (2026): Vol. 58 No. 4(2026): August
Publisher : Directorate for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2026.58.4.6

Abstract

Coolant bleed flow forecasting is critical for the engineering health of aircraft engines. Using the datasets from Commercial Modular Aero-Propulsion System Simulation (C-MAPSS), this paper aims to establish high-precision coolant bleed flow models by the random forest (RF) algorithm combined with tuna swarm optimization (TSO). 17 sensor variables that are moderately or highly correlated with the low-pressure turbine (LPT) and high-pressure turbine (HPT) are selected as inputs with LPT and HPT as outputs. After being trained and validated on the FD002 and FD004 datasets, the TSO-RF model significantly reduces mean squared error, mean absolute error and root mean squared error, and improves the determination coefficient R² compared to other RF models. It verifies the superiority of the TSO-RF model in predicting engine coolant bleed flow, providing reliable technical support for subsequent evaluation and management in aircraft engine bleed air system.
Charring Depth and Charring Rate of Resak and Jelutong Timber Beams in Two-Dimensional Fire Lannie Francis; Ahmad Beng Hong Kueh; Norshariza Mohamad Bhkari; Zakiah Ahmad; Hafizah Muhamad Azlan; Muhammad Bazli Faliq Mohd Puaad
Journal of Engineering and Technological Sciences Vol. 58 No. 4 (2026): Vol. 58 No. 4(2026): August
Publisher : Directorate for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2026.58.4.8

Abstract

Wood is a widely used material in building construction and infrastructure due to its environmental sustainability and economic benefits. However, timber structures are inherently vulnerable to fire hazards because of the combustible nature of wood. When exposed to fire, the strength and stiffness of timber members significantly decrease as a result of the charring process. In fire design for timber structures, charring depth and charring rate are critical parameters used to evaluate fire performance. This study aimed to investigate the charring characteristics, specifically, the charring depth and rate of solid timber from two Malaysian tropical hardwood species, namely Resak (Cotylelobium sp.), with a density of 1019 kg/m³, and Jelutong (Dyera costulata sp.), with a density of 506 kg/m³. Three beams from each species were subjected to a two-dimensional fire exposure for 60 minutes, following the standard fire testing procedure outlined in BS 476-20. The results indicated that Resak exhibited a lower lateral charring depth compared to Jelutong, averaging 25 mm and 45 mm, respectively. However, the bottom-side charring depths were similar for both species, measuring 54 mm for Resak and 53 mm for Jelutong. In terms of charring rate, Resak showed a lower value of 0.48 mm/min, while Jelutong had a higher rate of 0.83 mm/min. Both values fall within the acceptable range specified in Eurocode 5. A clear understanding of timber charring behavior, including both depth and rate, is essential for the safe and effective design of timber structures under fire conditions.
Hybrid Nanofluid-MQL and Cold Air Cooling for Hard Milling: RSM–PSO Multi-response Optimization The Vinh Do; Nguyen Anh Vu Le
Journal of Engineering and Technological Sciences Vol. 58 No. 5 (2026): Vol. 58 No. 5(2026): October
Publisher : Directorate for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2026.58.5.6

Abstract

This study investigates a hybrid cooling–lubrication approach combining nanofluid-assisted minimum quantity lubrication (MQL) with cold-air cooling in the hard milling of SKD11 steel, aiming to improve both surface quality and productivity. Response surface methodology (RSM) was employed to model the relationships between machining parameters and two key performance indicators, namely surface roughness (Ra) and material removal rate (MRR). The developed models were integrated with particle swarm optimization (PSO) for multi-objective optimization. Compared with conventional MQL, the hybrid approach reduced Ra by approximately 5–10% under similar cutting conditions, indicating enhanced cooling and lubrication performance. The optimization results revealed distinct trade-offs between surface quality and productivity. When surface quality was prioritized (wRa = 0.7), a minimum Ra of 0.160 µm was achieved with a relatively low MRR of about 653 mm³/min. In contrast, both the balanced (wRa = 0.5) and productivity-oriented (wRa = 0.3) scenarios converged to the same optimal solution (Ra ≈ 0.245 µm, MRR ≈ 1790 mm³/min). This convergence suggests that MRR dominates the optimization when its weighting is comparable to or higher than that of Ra, indicating a plateau region on the trade-off surface. The proposed RSM–PSO framework provides both an effective optimization approach and new insight into balancing surface integrity and productivity in hybrid-cooled hard milling
Damage Tolerance Characteristics of Woven-Carbon/Epoxy Laminates under Low-Velocity Impact: Insights from Tests and Simulations Muhamad Giri Suada; Haroen Romadon; Hendri Syamsudin
Journal of Engineering and Technological Sciences Vol. 58 No. 4 (2026): Vol. 58 No. 4(2026): August
Publisher : Directorate for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2026.58.4.10

Abstract

This study investigated the low-velocity impact damage tolerance of woven AS4/8552 carbon/epoxy laminates through combined drop-weight testing and finite element simulation. Five eight-layer [|±45°|/|90°/0°|/|±45°|/|0°/90°|]s specimens were impacted at 8.25 J, and the resulting internal damage was characterized using ultrasonic C-scanning. A detailed FEM model was developed in ABAQUS using SC8R continuum-shell elements for the laminae and COH3D8 cohesive-zone elements for interlaminar delamination, with Hashin failure criteria and the Benzeggagh–Kenane mixed-mode fracture law governing damage initiation and propagation. The numerical model reproduced the main experimental impact response, predicting a peak force of 4950 N compared with the experimental mean of 4360 N, corresponding to a 13% overestimation. The predicted delamination footprint also agreed well with C-scan observations, which showed delamination diameters ranging from 15.9 to 19.9 mm, with an average of 17.9 mm. However, the simulation underestimated absorbed energy by approximately 40% and produced smoother delamination boundaries than those observed experimentally. These discrepancies are attributed to the homogeneous cohesive-zone representation and continuum-shell formulation, which cannot fully capture fiber bridging, microcracking, interlaminar friction, and local stress perturbations caused by woven yarn undulations. The results demonstrate that the proposed framework is effective for predicting the global delamination extent and impact response of aerospace-representative woven laminates, while highlighting key improvements required for higher-fidelity damage-tolerance assessment.
A Comparative Study of Advanced Machine Learning and Deep Learning Models for Municipal Solid Waste Forecasting: A Case Study of Surat, India Abhijit R. Rathod; Vinodkumar M. Patel
Journal of Engineering and Technological Sciences Vol. 58 No. 5 (2026): Vol. 58 No. 5(2026): October
Publisher : Directorate for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2026.58.5.1

Abstract

To make the city planning sustainable, especially in rapidly growing cities of the world like Surat in India, the implementation of effective waste management is crucial.  The primary factor governing this is the ability to accurately predict the quantity of municipal solid waste (MSW) likely to be generated. This study presents a comprehensive comparative analysis of various predictive models including linear regressions, kernel approaches, gradient boosting as well as the deep learning architectures. Using historical data from Surat, systematic preprocessing and feature engineering generated 419 features representing temporal, socio-economic, climatic, COVID-19, and mobility factors. The novel contribution of this study is the systematic feature engineering framework that explicitly encodes temporal structure (419 engineered features including lagged values, rolling statistics, and seasonal decomposition), enabling simple linear models to capture complex waste generation patterns. Ten distinct models, ranging from statistical approaches to machine learning and deep learning were evaluated and compared. Advanced ensemble models, including LightGBM (R² = 0.983), CatBoost (R² = 0.977), and XGBoost (R² = 0.970) demonstrated strong performance. The best-performing models (OLS and Gaussian Process Regression) achieved R² = 0.997 with Mean Absolute Percentage Error (MAPE) = 1.43%. In this study, linear models trained within a few milliseconds and achieved per-sample inference times on the order of 0.004-0.008 ms, whereas the tuned MLP and tree-based ensembles required seconds of training and millisecond-level inference, corresponding to differences of roughly two to three orders of magnitude in computational cost. Other notable performers include Lasso regression (R² = 0.979), tuned MLP (R² = 0.968), and Random Forest (R² = 0.960). The results demonstrate that feature engineering has greater influence on forecasting accuracy than model complexity, with OLS using engineered features (R² = 0.997) outperforming the MLP model (R² = 0.966) by approximately 3.1% while providing substantially faster predictions. Feature importance analysis identified lagged MSW values, rolling statistics, demographic indicators, festival effects, and COVID-19 lockdown impact as key predictors. The research finds that adoption of systematically designed feature engineering framework is a valuable tool for MSW management. The study provides comprehensive model benchmarking and practical recommendations for policymakers pursuing sustainable urban development.
A Comparative Study of Snyder and Clark Hydrological Procedures for Flood Peaks Estimation Ebrahim Al-Qadami; Mohd Adib Mohammad Razi; Syed Muzzamil Hussain Shah; Mohamad Fahmi Ideris; Arman Mokhtar; Jaan H. Pu
Journal of Engineering and Technological Sciences Vol. 58 No. 5 (2026): Vol. 58 No. 5(2026): October
Publisher : Directorate for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2026.58.5.2

Abstract

The Snyder (HP11) and Clark (HP27) hydrological procedures are valuable tools in managing water resources in urban and rural areas across Malaysia. This study presents an extensive comparative assessment of these two procedures in estimating different watersheds flood peak flows. A total of 22 watersheds on Langkawi Island were simulated, representing a range of catchment types and characteristics, with catchment areas ranging from 1 to 68.2 km², and slopes between 1.54% to 24.77%, encompassing small to moderately large basins with gentle to steep terrain. For HP11 analysis, a Microsoft Excel spreadsheet was developed and used to perform the analysis based on triangular distribution of direct runoff following Snyder’s method. On the other hand, HEC-HMS software was used to perform hydrological analysis based on HP27 guidelines for both current and future land-use scenarios following Clark Unit Hydrograph Method. Obtained results were analyzed statistically using SPSS covering several parameters and tests. The results showed that the estimated design peak flows using HP11 procedure were higher compared with those estimated using HP27 for same land-use condition especially at higher ARIs. The percentage difference reached more than 70% depends on catchment characteristics. The estimated design peak discharge flows for future land use distribution were increased as expected due to the increment in the imperviousness of the catchment area, which contributes to higher peak discharge values as the critical storm duration shifts to a shorter period. Overall, the study demonstrates that the choice of hydrological procedure has a significant impact on flood estimation and should be carefully considered in future planning and design.
Influence of Machining Parameters on Surface Roughness in Trochoidal Milling of Ti-6Al-4V via Response Surface Methodology Nur Aina Farhanah Aziz; Norfauzi Tamin; Kahirol Mohd Salleh; Hairizal Osman; Tun Danish Tun Mohamed Kamarul
Journal of Engineering and Technological Sciences Vol. 58 No. 5 (2026): Vol. 58 No. 5(2026): October
Publisher : Directorate for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2026.58.5.3

Abstract

Machining of Ti-6Al-4V titanium alloy poses significant challenges, mainly due to its low thermal conductivity and tendency to form a built-up edge (BUE), which can lead to high surface roughness (Ra) and rapid tool wear. In this context, the trochoidal milling strategy emerges as a promising solution, as it can reduce thermal and mechanical loads by using a spiral-shaped tool path with intermittent contact between the tool and Ti-6Al-4V. Therefore, this research aims to evaluate the effectiveness and optimise the machining parameters, specifically, cutting speed (vc) and feed rate (vf), when using the trochoidal strategy for machining Ti-6Al-4V, with the primary objective of minimising Ra. The methodology used is Response Surface Methodology (RSM) with a Central Composite Design (CCD) to model the nonlinear relationships among vc, vf, and Ra. The experiment was conducted using a 3-axis CNC machining centre with carbide cutting tools. Based on the optimisation results, the optimal parameter combination to minimise Ra is 155 m/min for vc and 124 mm/min for vf. Experimental validation tests of the predicted optimal parameters yielded an Ra value of 0.118 μm, with an error of 2.47% relative to the RSM-predicted value, confirming the model’s applicability. In conclusion, this research confirms that targeted parameter optimisation using RSM is highly effective in improving the surface quality of Ti-6Al-4V, further proving the potential of the trochoidal strategy as an efficient method for critical applications in the aerospace and biomedical sectors where surface integrity is a prerequisite.

Page 17 of 18 | Total Record : 176

 14   15   16   17   18 

Filter by Year

2024 2026


Reset
Filter By Issues
All Issue Vol. 58 No. 5 (2026): Vol. 58 No. 5(2026): October Vol. 58 No. 4 (2026): Vol. 58 No. 4(2026): August Vol. 58 No. 3 (2026): Vol. 58 No. 3(2026): June Vol. 58 No. 2 (2026): Vol. 58 No. 2 (2026): April Vol. 58 No. 1 (2026): Vol. 58 No. 1(2026): February Vol. 57 No. 6 (2025): Vol. 57 No. 6 (2025): December Vol. 57 No. 5 (2025): Vol. 57 No. 5 (2025): October Vol. 57 No. 4 (2025): Vol. 57 No. 4 (2025): August Vol. 57 No. 3 (2025): Vol. 57 No. 3 (2025): June Vol. 57 No. 2 (2025): Vol. 57 No. 2 (2025): April Vol. 57 No. 1 (2025): Vol. 57 No. 1 (2025): February Vol. 57 No. 1 (2025): February Vol. 56 No. 6 (2024) Vol. 56 No. 5 (2024) Vol. 56 No. 4 (2024) Vol. 56 No. 3 (2024) Vol. 56 No. 2 (2024) Vol. 56 No. 1 (2024) More Issue