The Journal of King Mongkut’s University of Technology North Bangkok

คำแนะนำในการเตรียมต้นฉบับบทความวารสารวิชาการพระจอมเกล้าพระนครเหนือ

คำแนะนำในการเตรียมต้นฉบับบทความ วิชาการพระจอมเกล้าพระนครเหนือ — 2026-09-22

คำแนะนำในการเตรียมต้นฉบับบทความวารสารวิชาการพระจอมเกล้าพระนครเหนือ

Development of a Temperature-Controlled Product Packaging Process Using Designed Tools and ECRS Principles

Choosana Tiantong — 2026-09-03

This study aimed to improve the work process and develop an assistive device for the Temperature Control Product (TCP) box wrapping process in order to reduce operation time. The time study method was applied to determine the standard time, and a Fishbone Diagram together with brainstorming was used to analyze factors affecting work efficiency. The analysis revealed four key factors: 1) Tools–the lack of supporting tools resulted in longer working time; 2) Materials–the film was heavy, requiring workers to lift the film roll during operation, causing fatigue and reducing work efficiency; 3) Process–there were unnecessary steps and no proper data recording system; and 4) Work Environment–the workspace was not conducive to efficient operation. The improvement approach consisted of designing and developing a labor-saving device using SolidWorks to support tools and materials. The work process was improved by applying ECRS principles to reduce unnecessary steps and make the workflow more systematic, along with establishing a new standard time to compare results before and after the improvement. For the environmental aspect, the workspace was organized following the 5S methodology. The results indicate that the TCP box wrapping process initially consisted of 16 steps, which were reduced to 14 steps after improvement, representing a 12.50% reduction. In terms of standard time, the process decreased from 7 minutes and 47 seconds to 5 minutes and 14 seconds, corresponding to a reduction of 2 minutes and 33 seconds, or 32.63%.

Enhanced Antiradical and Anti-inflammatory Capacities of Thai Plant Extract Combinations: A Synergistic Study of Seven Traditional Plant Extracts

Pitchaon Maisuthisakul — 2026-09-11

This study aimed to evaluate the bioactivity and synergistic mechanisms of seven Thai plant extracts, namely mangosteen peel, emblic myrobalan, aloe vera, Indian pennywort, betel, paracress, and Cratoxylum formosum. The evaluation was conducted by determining total phenolic and total flavonoid contents, antioxidant capacity (DPPH assay), and antiproteinase activity. The results indicate that the individual extract of emblic myrobalan possessed the highest total phenolic content (332.46 ±6.84 mg GAE/g plant, DB), whereas mangosteen peel exhibited the highest total flavonoid content (89.19 ±2.45 mg QE/g plant, DB). Furthermore, mangosteen peel and emblic myrobalan demonstrated comparable antiradical capacities, with EC50 values of 0.80 ±0.04 and 0.74 ±0.07 µg/mL, respectively. Functional interaction analysis using the Combination Index (CI) revealed significant synergism (p-value ≤ 0.05) across all binary formulations. Notably, the synergistic blend of mangosteen peel and emblic myrobalan exhibited the most potent antiradical activity (EC50 = 0.65 ±0.03 µg/mL), correlating with an increased total phenolic content (342.92 ±4.11 mg GAE/g plant, DB). Additionally, most herbal combinations demonstrated superior antiproteinase activity compared to their individual extracts, with the combination of mangosteen peel and betel achieving near-complete inhibition (98.03%). These findings imply that the interaction among phenolic compounds, flavonoids, and other phytochemicals significantly enhances the efficacy of combined extracts. This study supports the application of these synergistic formulations in the development of innovative health products and cosmeceuticals targeting oxidative stress and inflammation.

Accuracy Assessment of Above-Ground Carbon Estimation in Oil Palm Plantations Using UAV-Based Geo-Information Technology

Jirawat Jantongpoon — 2026-09-15

Accurate estimation of above-ground carbon is essential for carbon accounting and carbon credit verification. However, field-based tree height measurements are constrained in areas with dense canopy cover. This study aims to develop and evaluate the accuracy of a method for estimating oil palm tree height and above-ground carbon across different age classes Using Unmanned Aerial Vehicle (UAV) data. The study was conducted in oil palm plantations aged 6, 8, and 10 years in Phatthalung Province, Thailand, with sample sizes of 39, 54 and 43 trees, respectively (a total of 136 trees). UAV imagery combined with Global Navigation Satellite System (GNSS) data was used to generate a Digital Surface Model (DSM), Digital Terrain Model (DTM), and Canopy Height Model (CHM), and accuracy was assessed by comparison with total station measurements. The results indicate that the 6 year and 10 year plantations showed good agreement (R² = 0.703 and 0.731; RMSE = 0.972 and 0.843 m, respectively), whereas the 8-year plantation exhibited the highest error (RMSE = 1.076 m), mainly due to canopy overlap and uncertainties in the terrain model. In terms of carbon, the estimated values were 3,317.565, 10,362.015 and 8,761.218 kg C, with the highest value observed in the 8 year plantation. The findings suggest that although the height estimation errors ranged from 0.84 to 1.08 m, they remain within an acceptable level and can support MRV systems and plot-level carbon credit assessment.

Preparation of Low-Temperature-Fired Sustainable Ceramic Tiles Using Municipal Waste Incineration Fly Ash, Green Glass Waste, and Lampang Kaolin

Purinut Maingam — 2026-07-24

This study examines the feasibility of producing sustainable ceramic tiles using Municipal Solid Waste Incineration Fly Ash (MSWI FA), Green Glass Waste (GGW), and Lampang Kaolin (LK). Ten experimental mixtures were formulated using a ternary mixture design and categorized into four series with MSWI FA contents of 0, 10, 20, and 30%, respectively. The specimens were uniaxially pressed at 10 MPa and subsequently fired at 850°C and 950°C. The physical properties, including flexural strength, water absorption, linear shrinkage, weight loss after firing, and bulk density, were evaluated. In addition, flexural strength and water absorption were compared with the requirements of the EN 14411 standard for ceramic tiles. The results indicate that mixtures without MSWI FA, containing 60–70% GGW when fired at 850°C and 50–70% GGW when fired at 950°C, satisfied the EN 14411 requirements for both flexural strength and water absorption. Moreover, mixtures incorporating 10% MSWI FA fired at 850°C and 20% MSWI FA fired at 950°C also met the EN 14411 criteria. Optical microscopy supported these findings by revealing enhanced glassy phase formation and increased densification at higher firing temperatures. Furthermore, the combined CaO-rich fluxing oxides derived from GGW and MSWI FA may facilitate the stabilization of hazardous heavy metals within the ceramic matrix, thereby supporting sustainable ceramic tile production, energy-efficient firing, and effective waste valorization.

A Comparative Analysis of Clustering Schemes and Optimal Forecasting Models for Spare Parts Demand Forecast in Maintenance Operation

Thawanluck Jinasee — 2026-09-14

This study aims to identify the most appropriate clustering scheme and forecasting method for spare parts used in maintenance operations with heterogeneous demand characteristics. The proposed methodology first classifies spare parts based on the Average Demand Interval (ADI) and the Squared Coefficient of Variation (CV²). Four clustering techniques are compared: demand segmentation based on demand patterns, K-means clustering, hierarchical clustering, and Density-Based Spatial Clustering of Applications with Noise (DBSCAN). The empirical analysis is conducted using monthly demand data from 2020 to 2023 (48 months) covering 1,735 spare parts. Demand data from 2020 to 2022 (36 months) are used as the training set for model development and parameter calibration, while data from 2023 (12 months) are used as the test set to evaluate out-of-sample forecasting performance. For each cluster, demand is forecast using the Simple Moving Average (SMA), Holt’s exponential smoothing method, Croston’s method, and the Autoregressive Integrated Moving Average (ARIMA) model. Forecast accuracy is evaluated using the Symmetric Mean Absolute Percentage Error (sMAPE). The results indicate that DBSCAN combined with the ARIMA model provides the lowest sMAPE values across all clusters. Specifically, cluster 1, cluster 2, cluster 3, and cluster 4 achieve sMAPE values of 3.01%, 27.03%, 5.37%, and 4.17%, respectively. These findings demonstrate the effectiveness of integrating clustering and forecasting techniques for spare-parts demand forecasting in maintenance operations.

Equivalent Out-of-Plane Shear Center of Steel Howe Truss

Navin Pinlom — 2026-09-07

Evaluating the out-of-plane stiffness of a steel truss by comparing the behavior of the steel truss with that of a steel beam with a single symmetric cross section is possible. However, the location of the shear center is required. For a steel beam, the location of the shear center can be easily calculated. However, calculating the position of the shear center of a steel Howe truss is not possible due to the discontinuity of the web members. This research therefore investigates the relationship between the position of the equivalent out-of-plane shear center and the dimensions of the truss. From the study, it was found that the location of the equivalent out-of-plane shear center can be located both inside and outside the depth of the truss. It depends on the moment of inertia of the chord and web members. When the moment of inertia of the chord members increases, the percentage of the equivalent out-of-plane shear center position measured from the top chord decreases. A truss with a lower moment of inertia of the web members also has a lower percentage location of the equivalent out-of-plane shear center. This research also proposes an equation to calculate the equivalent out-of-plane shear center location of a steel howe truss, which is modified from the equation for a steel beam. The proposed equation shows good results under specific conditions.

Influence of Swirl Number on Flame Stability of an LPG Premixed Swirl Burner under Free-Flame Conditions

Sumeta Sribun — 2026-09-07

Swirl burners are widely used in energy and industrial applications due to their ability to enhance fuel–air mixing and stabilize flames. However, a detailed understanding of Liquefied Petroleum Gas (LPG) combustion in premixed swirl burners under free-flame conditions remains limited. Free-flame operation minimizes wall-confinement effects and allows clearer observation of intrinsic swirl-induced flame stabilization mechanisms. This study numerically investigates the combustion behavior of an LPG-fueled premixed swirl burner, focusing on the effects of equivalence ratio, Reynolds number, and swirl number on flame structure and stability. Computational Fluid Dynamics (CFD) simulations were performed by solving the governing equations of mass, momentum, energy, and species transport. Turbulence was modeled using the RNG k–ε approach, while combustion was represented by the partially premixed combustion model coupled with the discrete ordinates radiation model. The numerical model was validated against experimental data, showing good agreement with a mean error of 8.19%, indicating its reliability. Simulations were conducted for Reynolds numbers of 2,000, 4,000 and 6,000 and equivalence ratios of 0.8, 1.0 and 1.2. The results indicate that lean flames are elongated, stoichiometric flames are compact and symmetric, and rich flames exhibit thicker reaction zones. Increasing Reynolds number improves fuel–air mixing and flame stability. The condition at Reynolds number 6,000 and equivalence ratio 0.8 yields the highest swirl number, producing a strong central recirculation zone, a well-anchored flame, and a maximum temperature of 2,079 K. These findings confirm that swirl number is a key parameter in the design of premixed swirl burners to improve combustion efficiency and flame stability.

Influence of Process Parameters on Mechanical Properties of 5356 Aluminum Alloy Fabricated by Wire Arc Additive Manufacturing Technology

Manoch Numfu — 2026-09-03

This research investigates the influence of process parameters on the mechanical properties of aluminum alloy 5356 fabricated using Wire Arc Additive Manufacturing (WAAM) technology. Thin-wall test specimens were produced by robotic welding, considering three key process parameters: Wire Feed Speed (WS), Travel Speed (TS), and shielding Gas Flow Rate (GF). The effects of these factors on tensile force and hardness were analyzed. The results indicate that travel speed is the most influential parameter on tensile force. The optimal combination of parameters, with WS of 6 m/min, TS of 0.4 m/min, and GF of 10 L/min, yielded the maximum tensile force of 4,918.69 N. Conversely, a combination of WS of 7 m/min, TS of 0.4 m/min, and GF of 14 L/min resulted in a reduced tensile force of 4,703.35 N. In terms of hardness, the shielding gas flow rate exhibited the most significant effect. The highest hardness value of 38.95 HRB was obtained with WS of 6 m/min, TS of 0.4 m/min, and GF of 10 L/min, while the lowest hardness value of 37.15 HRB occurred with WS of 8 m/min, TS of 0.4 m/min, and GF of 14 L/min. These findings confirm that variations in the three process parameters significantly affect the mechanical properties of WAAM-fabricated specimens. Therefore, in applying Wire Arc Additive Manufacturing (WAAM) to fabricate Al5356 thin-walled components, travel speed should be prioritized as the primary factor to achieve high tensile force. Furthermore, an appropriate shielding gas flow rate should be carefully selected to ensure the desired hardness.

Fighting Plant Diseases in the Climate Crisis: Sustainable Management Strategies for a Global Boiling Era

Patcharavipa Chaijuckam — 2026-08-24

เกือบ 20 ปีที่ผ่านมา ได้มีการกล่าวถึงปัญหาภาวะโลกร้อน (Global Warming) และการเปลี่ยนแปลงสภาพภูมิอากาศหรือภาวะโลกรวน (Climate Change) อย่างกว้างขวาง [1] คำว่า “Global Warming” และ “Climate Change” มักถูกใช้แทนกัน แต่แท้จริงแล้วมีความหมายต่างกัน Global Warming เป็นสภาวะที่โลกมีอุณหภูมิเฉลี่ยสูงขึ้นในระยะยาว ส่วน Climate Change คือ การเปลี่ยนแปลงสภาพภูมิอากาศโดยรวมของโลก ครอบคลุมถึง Global Warming และผลกระทบอื่น ๆ เช่น ฝนตกหนัก ภัยแล้ง ระดับน้ำทะเลที่สูงขึ้น การเปลี่ยนแปลงของช่วงเวลาที่ดอกไม้ผลิบาน ซึ่งเป็นผลสืบเนื่องมาจากโลกร้อนมากขึ้น [2]

Prediction of Feature Importance for YouTube Premium Cancellation Using Artificial Neural Network and Ensemble Learning Algorithms

Chakkarin Santirattanaphakdi — 2026-08-19

This research aims to develop a high-performance predictive model for subscriber churn in the YouTube Premium service and to identify key determinants influencing user decisions, providing a basis for proactive customer retention strategies. Utilizing a dataset of 10,983 records, the study integrates Artificial Neural Networks (ANN) with ensemble learning algorithms, specifically XGBoost, LightGBM, and CatBoost. The methodology incorporates Optuna for hyperparameter optimization and an iterative feature selection framework combined with SHAP (SHapley Additive exPlanations) for model interpretability. The results demonstrate that the optimized LightGBM model, adjusted for class imbalance, achieves superior performance, with an Area Under the Curve (AUC) of 0.93, an accuracy of 0.85, and a recall of 0.90, while utilizing only eight critical variables. The analysis reveals that behavioral factors significantly outweigh demographic variables in predicting churn. Positive indicators for retention include “ContentCount” which exerts the highest influence, followed by “Period” “WatchTime” and “Subscribed” (number of channels followed). Conversely, “CamelCase” and “SupportTickets” are identified as critical negative indicators that significantly increase churn risk. Additionally, “Contract” type and “TechSupport” serve as supplementary factors in reducing cancellation rates. These findings not only validate the effectiveness of ensemble learning in handling complex behavioral data but also provide strategic insights for monitoring users with low engagement or transaction-related issues. Implementing these proactive measures can effectively mitigate customer loss and ensure long-term business sustainability.

ปกวารสารวิชาการพระจอมเกล้าพระนครเหนือ

ปกวารสาร มจพ. วารสารวิชาการพระจอมเกล้าพระนครเหนือ — 2026-09-22

บรรณาธิการวารสารวิชาการพระจอมเกล้าพระนครเหนือ

บรรณาธิการ วารสารวิชาการพระจอมเกล้าพระนครเหนือ — 2026-09-22

บรรณาธิการวารสารวิชาการพระจอมเกล้าพระนครเหนือ