EAI Endorsed Transactions on Sustainable Manufacturing and Renewable Energy
The aim of EAI Endorsed Transactions on Sustainable Manufacturing and Renewable Energy is to serve as an advanced forum for researchers, scholars, practitioners, and policymakers to disseminate cutting-edge research and advancements in sustainable manufacturing and renewable energy. This journal focuses on interdisciplinary collaboration and provides insights into sustainable practices, technologies, and methodologies that contribute to the global transition towards environmentally responsible manufacturing and energy systems. INDEXING: Google Scholar, Crossref, Dimensions, Semantic Scholar, Lens
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Robust Hybrid LQR - Integral Control for 2-DOF Robotic Arms: Performance Evaluation under Simulated Agricultural Vibration Conditions
Robotic technologies, particularly robotic manipulators, play an important role in both industrial automation and smart agriculture. In agricultural sectors where automation remains underutilized and labor cost is high, robotic solutions are necessary for enhancing productivity. However, developing agricultural robots faces significant challenges due to harsh environmental conditions, limited resources, and strict human-robot collaboration safety requirements. Consequently, advanced control algorithms are critical for maintaining high precision under operational disturbances, such as vibrations from internal combustion engine-powered tractors. This study proposes a robust Linear-Quadratic Regulator combined with Integral control (LQR-KI) for 2-DOF flexible joint robots. While flexible joint manipulators offer a safety and reduced structural weight compared to traditional rigid systems, they are affected by complex, non-ideal coupling vibrations. The proposed control structure focuses on enhancing stability and positioning accuracy, with its robustness verified through an extensive analysis of closed-loop pole trajectories under non-ideal agricultural excitations. Numerical simulations demonstrate that the LQR - KI scheme effectively isolates base vibrations, achieving a significant link positioning accuracy of 0.03 (rad). Especially, the results validate that the flexible joint configuration, optimized by the proposed controller, can achieves approximately 9.36% energy savings compared to conventional rigid-link counterparts. This research contributes to sustainable production by providing a high-performance, energy-efficient solution for integrating advanced robots into existing agricultural platforms
Copyright (c) 2026 N. L. Quang https://creativecommons.org/licenses/by-nc-sa/4.0
Evaluating the Impact of Integrated Reflective Louver Daylighting and LED Dimming Control Systems on Visual Comfort and Cognitive Performance in Office Environments
The drive towards Zero-Energy Buildings (ZEB) necessitates optimized lighting energy solutions. Integrated technologies combining daylight-concentrating louvers and LED Dimming Control have been shown to significantly reduce energy consumption. However, the impact of these dynamic lighting changes on occupants' visual comfort and work performance remains a research gap. This study aims to evaluate the balance between energy efficiency and occupant comfort by integrating the Daylight Glare Probability (DGP) into the control algorithm. Three lighting scenarios were tested in a simulated office mock-up: A (Baseline: LED ON/OFF), B (Energy Optimization: Dimming based on average illuminance), and C (Comfort Optimization: Dimming based on both illuminance and DGP<0.35). The results demonstrate that Scenario C achieved an average energy saving of 75.7% compared to Scenario A, while successfully maintaining the Daylight Glare Probability (DGP) at an acceptable level (DGP≤0.35). Crucially, Scenario C resulted in an 8.1% faster cognitive reaction time and 50% fewer errors compared to Scenario B, proving that a comfort-prioritized control strategy not only saves energy but also enhances cognitive performance. The study proposes a dual-factor (Illuminance, DGP) control model as the sustainable operational standard for future ZEB lighting systems.
Copyright (c) 2026 Quan-Truong Vuong https://creativecommons.org/licenses/by-nc-sa/4.0
Experimental test to analyze and evaluate the exergy and energy efficiency of the AHU in the Waterchiller system
Experimental study to determine the impact of changing AHU operating parameters on exergy and energy efficiency in the water chiller system. The study used both an experimental method and theoretical calculations, with a Trane-brand chiller system with a cooling capacity of 25,3 kW. The results showed that when the supply air temperature increased from 295 K to 299 K, the heat exchanger's exergy consumption (<!-- [if gte msEquation 12]><m:oMath><m:sSub><m:sSubPr><m:ctrlPr></m:ctrlPr></m:sSubPr><m:e><m:r>X</m:r></m:e><m:sub><m:r>cons</m:r><m:r>,</m:r><m:r>HE</m:r></m:sub></m:sSub></m:oMath><![endif]--> <span style="font-size: 12.0pt; line-height: 115%; font-family: 'Aptos',sans-serif; mso-ascii-theme-font: minor-latin; mso-fareast-font-family: 'Times New Roman'; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: 'Times New Roman'; mso-bidi-theme-font: minor-bidi; position: relative; top: 3.0pt; mso-text-raise: -3.0pt; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;"> ) decreased from 0.2 kW to about 0.05 kW. The exergy consumption of the heat exchanger (<!-- [if gte msEquation 12]><m:oMath><m:sSub><m:sSubPr><m:ctrlPr></m:ctrlPr></m:sSubPr><m:e><m:r>X</m:r></m:e><m:sub><m:r>cons</m:r><m:r>,</m:r><m:r>HE</m:r></m:sub></m:sSub></m:oMath><![endif]--> <span style="font-size: 12.0pt; line-height: 115%; font-family: 'Aptos',sans-serif; mso-ascii-theme-font: minor-latin; mso-fareast-font-family: 'Times New Roman'; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: 'Times New Roman'; mso-bidi-theme-font: minor-bidi; position: relative; top: 3.0pt; mso-text-raise: -3.0pt; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;"> ) and the exergy flow of the return air to the AHU (<!-- [if gte msEquation 12]><m:oMath><m:sSub><m:sSubPr><m:ctrlPr></m:ctrlPr></m:sSubPr><m:e><m:r>X</m:r></m:e><m:sub><m:r>a</m:r><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr>,</m:r><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/><m:nor/></m:rPr> re </m:r></m:sub></m:sSub></m:oMath><![endif]--> <span style="font-size: 12.0pt; line-height: 115%; font-family: 'Aptos',sans-serif; mso-ascii-theme-font: minor-latin; mso-fareast-font-family: 'Times New Roman'; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: 'Times New Roman'; mso-bidi-theme-font: minor-bidi; position: relative; top: 3.0pt; mso-text-raise: -3.0pt; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;"> ) were almost constant, maintained at about 0.95 kW and 0.8 kW, showing that the efficiency of the heat exchanger and the exergy of the ambient air were relatively stable, not much affected by changes in ambient temperature. When the inlet water temperature (<!-- [if gte msEquation 12]><m:oMath><m:sSub><m:sSubPr><m:ctrlPr></m:ctrlPr></m:sSubPr><m:e><m:r>X</m:r></m:e><m:sub><m:r>w</m:r><m:r>,</m:r><m:r>in</m:r></m:sub></m:sSub></m:oMath><![endif]--> <span style="font-size: 12.0pt; line-height: 115%; font-family: 'Aptos',sans-serif; mso-ascii-theme-font: minor-latin; mso-fareast-font-family: 'Times New Roman'; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: 'Times New Roman'; mso-bidi-theme-font: minor-bidi; position: relative; top: 3.0pt; mso-text-raise: -3.0pt; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;"> ) increases from 284 K to 289 K. The water exergy flow (<!-- [if gte msEquation 12]><m:oMath><m:sSub><m:sSubPr><m:ctrlPr></m:ctrlPr></m:sSubPr><m:e><m:r>X</m:r></m:e><m:sub><m:r>w</m:r></m:sub></m:sSub></m:oMath><![endif]--> <span style="font-size: 12.0pt; line-height: 115%; font-family: 'Aptos',sans-serif; mso-ascii-theme-font: minor-latin; mso-fareast-font-family: 'Times New Roman'; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: 'Times New Roman'; mso-bidi-theme-font: minor-bidi; position: relative; top: 2.5pt; mso-text-raise: -2.5pt; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;"> ) decreases linearly from about 1.3 kW to about 0.8 kW. In addition, this study also evaluates the impact of changing the chilled water pump frequency and air flow rate on energy efficiency. The results indicate that the optimal operating point is not at the maximum frequency but at about 45 Hz, at which the cooling capacity reaches 7,764 kW.
Copyright (c) 2025 Van Cuong Bui, Duc Khuyen Nguyen, Thanh Nhan Phan https://creativecommons.org/licenses/by-nc-sa/4.0
A Comparative Analysis of Optimal LQR and Conventional PID Control Strategies for Trajectory Tracking in a 3-DOF Spherical Articulated Manipulator
The demand for high-precision, energy-efficient control in industrial robotics necessitates a rigorous comparison between conventional and optimal control methods. This paper presents a detailed comparative analysis of the ubiquitous PID (Proportional-Integral-Derivative) controller and the modern LQR (Linear Quadratic Regulator) optimal controller, applied to the highly non-linear dynamics of a 3-DOF spherical articulated manipulator. The study extends beyond ideal tracking to evaluate performance under realistic industrial constraints, including external disturbances, model uncertainty, and the novel scenario of actuator saturation. Through comprehensive MATLAB/Simulink simulations, we quantify performance using Root Mean Square Error (RMSE) and Integrated Control Effort (∫τ2dt). The results demonstrate that while PID is simple, LQR provides superior stability, higher resistance to parameter uncertainty, and optimal energy consumption across dynamic trajectories. This work offers quantitative guidance for selecting the appropriate controller based on specific industrial requirements, highlighting the trade-offs between implementation complexity and optimal system performance
Copyright (c) 2026 Chau Nhan Phuc Pham, Minh Tan Tram, Quan-Truong Vuong https://creativecommons.org/licenses/by-nc-sa/4.0
Stabilization of a Cart-Pendulum System Using the Pole Placement Technique
This study addresses the stabilization of the Cart Inverted Pendulum (CIP), a system widely recognized as a foundational challenge in control theory because of its unstable, nonlinear, and under controlled properties. Achieving stability in the CIP is essential for developing control methods for modern applications like robotics. This paper implements the Pole Placement method to ensure the system remains stable. The method begins by linearizing the nonlinear system dynamics about the unstable vertical configuration and expressing them in a state-variable form. After confirming the system's controllability, a state-feedback controller is designed by strategically assigning closed-loop pole locations. This placement dictates the system's performance, allowing for specific targets for damping and setting time. The controller's effectiveness is demonstrated through numerical simulations in MATLAB/Simulink, which confirm the system's successful transition from instability to stable, regulated control of both the angle of pendulum and the position of cart. This analysis also illuminates the essential trade-off between the system's response speed and the required energy control. The work ultimately affirms that Pole Placement is a highly effective, understandable, and computationally practical technique for stabilizing complex underactuated systems.
Copyright (c) 2026 Quan Bui Khanh Minh, Hung Nguyen Ngoc, Trung Duong Thanh https://creativecommons.org/licenses/by-nc-sa/4.0
Online PID Parameter Optimization Using Genetic Algorithm for a Wind Power Generation System
INTRODUCTION: In wind power generation systems, the unstable variability of wind energy significantly affects control quality and power stability. Conventional PID controllers often show limitations in nonlinear systems or systems with time-varying parameters, especially when integral windup and degraded transient performance occur. OBJECTIVES: This paper proposes an online optimization method for PID parameters based on a Genetic Algorithm (GA), applied to a simplified dynamic model of a wind power generation system, in order to improve the system response quality. METHODS: The studied system is modeled by a second-order transfer function representing the system’s inertia and friction characteristics. The GA is implemented in a real-time optimization manner, using an objective function based on the ITAE criterion to evaluate and select the optimal PID parameter set. RESULTS: Simulation results show that the proposed online GA–PID approach improves settling time, reduces overshoot, and eliminates steady-state error more effectively than fixed PID and conventional anti-windup PID controllers. CONCLUSION: The proposed online GA–PID method is suitable for energy systems with high variability and adaptive control requirements, especially in wind power generation applications.
Copyright (c) 2025 Huy Ngô, Ngo Dinh Gia Huy https://creativecommons.org/licenses/by-nc-sa/4.0
Advanced Delta Robot Control Using Adaptive Neural PID with Recurrent Fuzzy Neural Network Modeling
This study presents an adaptive control method for a 3-degree-of-freedom parallel Delta robot using a neuron PID controller combined with a recurrent fuzzy neural network (RFNN) identifier. Due to the nonlinear kinematics and dynamics, coupling, and load changes of the Delta robot, traditional PID controllers often do not ensure optimal control quality, thereby requiring adaptive intelligent control techniques [1], [2]. In the proposed model, the PID is represented as a linear neuron capable of self-updating the parameters Kp​, Ki​, Kdd based on the Jacobian information estimated online by the RFNN identifier, inheriting the backpropagation learning principle in the recurrent neuro-fuzzy system [3]. MATLAB simulation results show that the response time is improved, the steady-state error is eliminated, and the system maintains its stability when the load changes, which is consistent with previous studies on neural network-based adaptive PID for nonlinear systems [4]–[6]. This method contributes to affirming the effectiveness of combining PID neuron and RFNN for precise control of parallel robots.
Intelligent Systems and Digital Innovations in Agricultural Applications
Copyright (c) 2026 H.Q. Nhan, V.B. Dung, P.B.D. Loc https://creativecommons.org/licenses/by-nc-sa/4.0
Study on the dyeing effectiveness and the antibacterial ability of cotton fabric 100% using the extract from Muntingia Calabura leaves
In the context of the textile industry, which is the second largest polluter in the world just after the oil industry, the demand for natural components is increasing. And the environmental damage is increasing as the industry grows. This study focuses on Muntingia calabura leaves with the aim of exploring natural colorants capable of dyeing cotton fabric as a substitute for chemical dyes and developing an antibacterial finishing method for cotton fabric. The study employs color extraction methods using Ethanol 60% solvent and Deep Eutectic Solvents (DES), and dyeing is performed using microwave irradiation. Color measurement is conducted using an X-Rite Color i5 spectrophotometer, and color parameters are analyzed in the CIELab. Furthermore, the presence of antibacterial substances on the treated fabric is determined by FTIR spectroscopy, and the antibacterial efficacy of the treated cotton fabric is evaluated against two bacterial strains: gram-negative E. coli and gram-positive S. aureus. The Muntingia calabura leaves’ extract demonstrated the ability to dye cotton fabric with Delta E of 36,53 (Ethanol 60%), 39,95 (DES) and the K/S color strength of 5,613 (Ethanol 60%), 6,576 (DES), along with impressive antibacterial activity, achieving up to 100% against E. coli and 96,5% against S. aureus. The dyed fabric exhibited high rubbing fastness at level 5 for both solvents in dry rubbing fastness and exhibited quite good color staining fastness to washing, reaching level 4-5.
Copyright (c) 2026 Hue Trinh Thi Kim, Thao Thach Phan https://creativecommons.org/licenses/by-nc-sa/4.0
Study on the assessment of absorbed energy of bulbous bow in ship collision
The evaluation of energy absorption characteristics of the bulbous bow structure in ship collisions or grounding accidents is a crucial research area. Predicting dynamic reactions or determining the collision energy absorption capability of the bulbous bow structure during impacts is essential in the design process. This paper investigates the collision behavior of the bulbous bow structure impacting a rigid wall using numerical simulations conducted with the commercial finite element code FEA. Namely, impact force histories on the bulbous bow structure, crushing depths/displacements, and collision energy absorption of the ship structure during impact are numerically determined under, consideration of different collision velocities, ship masses, impact angles and impact positions. The FEM results will be compared to results obtained from AASHTO. The results indicate that collision forces, deformations of the bulbous bow structure, and absorbed collision energies can be effectively predicted using current numerical simulation. The maximum collision force and energy absorption are directly influenced by the collision velocity and mass of the impacting ship. Notably, variations in collision positions (𝐻𝐻) and impact angles (𝛼𝛼) result in differences in collision forces and deformations at the bulbous bow structure. Therefore, careful consideration of parameters (𝐻𝐻) and (𝛼𝛼) is crucial to predict structural damage effectively. In addition, the pre-and post-collision motion behavior of the ship is also evaluated using a 6-degree-of-freedom (6 DOF) system.
Copyright (c) 2025 Quyen Tran-manh, Hai Tran, Tao Tran-van https://creativecommons.org/licenses/by-nc-sa/4.0
The application of Adaptive Large Neighborhood Search in Home Health Care Routing and Scheduling problem
Due to an aging population, a significant increase in demand for Home Health Care (HHC) services in most developed and developing countries. This paper addresses the considerations of costs including transportation cost, caregiver’s cost and patients’ load. To mitigate the issue, the objective is to minimize the costs and considerate the patient's load. The resource is defined as an arrangement for patient’s load. The deterministic model is solved by CPLEX, and the Adaptive Large Neighborhood Search based on heuristics.
Copyright (c) 2026 Le Minh Thao Nguyen, Nguyen Ky Phuc Phan, Hoai Phuong Le https://creativecommons.org/licenses/by-nc-sa/4.0
Optimizing the Needle - Thread - Fabric Interaction for Enhanced Seam Performance in Clothing Manufacturing
In apparel industry, product quality is always the key factor determining the success of a business. Not only does this create customer satisfaction, but product quality also directly affects the business's reputation, competitiveness, and market expansion opportunities. In this, seam appearance is one of the most important quality requirements, directly determining customer satisfaction. This paper examines the relationship and impact of three most important specifications, including needle-thread compatibility, fabric weight on the quality of seam performance. Through the experiment according to the full factorial design, this paper has determined the influence of each factor, in which the fabric weight is the factor with the most significant impact on the variation of the seam length, followed by the needle size and thread size. Determining the relationship between material parameters (fabric, thread) and equipment parameters (needle) not only helps to minimize errors but also creates the premise for building standardization processes for technical parameters according to each specific product group. These results will support the operator to adjust the machine faster, more accurately and less dependent on manual experience, thereby improving productivity and efficiency of the whole system.
Copyright (c) 2025 Song Thanh Quynh Le, Thuy My Nguyen Thi https://creativecommons.org/licenses/by-nc-sa/4.0
Research into the Influence of the Ease Coefficient on the Fit of Torso Dresses
This approach offers an alternative method for size selection, one that accounts for the inherent variability in body measurements, thus providing a more tailored and accurate fit for consumers. This study aims to establish a dataset of ease coefficients for torso pattern design across various fabric types and body shapes to ensure proper garment fit. Data were collected from 120 women aged 18–30 in Ho Chi Minh City. Using principal component analysis, K-means clustering, discriminant analysis, and ANOVA via SPSS, participants were classified into four distinct body shape groups. A basic dress pattern was developed based on the average measurements of each group and simulated on different woven fabrics to assess fit and make necessary adjustments. The correlation between body-specific and average-group patterns was analyzed, resulting in a table of ease coefficients for multiple fabric types. Fit evaluations were conducted through 3D simulation and wearer feedback. The study provides ease coefficient data for the bust, waist, and hip areas of Vietnamese women aged 18–30, offering a foundation for the design of dresses and blouses in the fashion industry.
Copyright (c) 2025 Mong Hien Thi Nguyen, Phuong Nhi Thi Le https://creativecommons.org/licenses/by-nc-sa/4.0
Design and Implementation of a Line-Tracking Robot for Autonomous Navigation
This study presents the design and implementation of a line-following Automated Guided Vehicle (AGV) for stock distribution using color detection. The AGV incorporates mechanical, electrical, and control engineering principles to improve warehouse automation. The primary goal is to develop an AGV that autonomously follows a designated path and sorts stocks by color. This project enhances students’ understanding of mechatronics system design by integrating fabrication, sensor integration, embedded programming, and control system optimization. The methodology includes system modeling, hardware selection, circuit design, algorithm implementation, and experimental validation. The AGV’s performance was assessed under different conditions to evaluate accuracy, stability, and adaptability. The AGV successfully follows predefined paths and accurately classifies stocks by color, optimizing logistics and automation processes. Experimental and simulation data confirm the system’s effectiveness. This project establishes a fundamental framework for AGV-based logistics and contributes to the advancement of autonomous warehouse solutions.
Copyright (c) 2025 L. H. Huynh, D. T. Duong, Lourve Vincent https://creativecommons.org/licenses/by-nc-sa/4.0
FEM-Based Analysis of Interference Fit for High-Precision Mechanical Assemblies
This study presents an interference fit study that supports the design and evaluation of press-fit assemblies. The simulation model is based on the Thick-Walled Cylinder Theory (TCT) to accurately predict contact pressure, pressing force, and stress distribution during assembly and disassembly. The shaft-bearing assembly is machined with high precision for experimentation. The results show good agreement between the FEM simulation and the theoretical stress distribution, confirming the mechanical behavior of the interference fit. Experimental verification of the pressing force is also performed and compared with the simulation, showing consistent trends. The simulation model helps evaluate the assembly performance in different tolerance and coefficient of friction domains, providing a practical solution for high-precision mechanical assemblies.
Copyright (c) 2025 Minh Nhat Truong https://creativecommons.org/licenses/by-nc-sa/4.0
An Optimization Model for Reverse Logistics of Electric Vehicle Batteries
Currently, the trend toward sustainable development is a top priority in the economic and social agendas of countries worldwide. This global commitment is clearly reflected in the rapid adoption and expansion of electric vehicles, which are widely regarded as a key solution to reducing greenhouse gas emissions and minimizing dependence on fossil fuels. However, the accelerated deployment of EVs has also led to new challenges, particularly the scarcity of critical metals such as lithium, nickel, and cobalt essential elements in the production of lithium-ion batteries. It points out the need for efficient and sustainable systems for battery recovery, recycling, and reuse. This study addresses this challenge by proposing an optimization model for the design and operation of a reverse logistics system dedicated to electric vehicle battery repair, recovery, and recycling. The model integrates three fundamental decision-making dimensions: firstly, the optimal location of battery repair centers; secondly, the selection and placement of recovery and recycling facilities; and the final one is the determination of inventory levels and transportation quantities between all nodes in the system. The model is formulated as a Mixed-Integer Linear Programming (MILP) problem and is optimally solved using CPLEX and Excel. In addition to minimizing total costs including transportation, inventory, and facility opening costs the model explicitly incorporates environmental objectives by reducing carbon emissions from logistics activities and processing technologies. Moreover, although the model is developed for electric vehicle batteries, it can be generalized to other types of electronic waste to support broader circular economy initiatives. The results offer practical implications for supply chain managers, policymakers, and sustainability advocates in designing greener and more resilient reverse logistics networks.
Copyright (c) 2025 Vinh-Thanh Phan, Thuy-Nhi Le Nguyen, Ivan Kristianto Singgih https://creativecommons.org/licenses/by-nc-sa/4.0
The Fuzzy AHP for Prioritizing Factors in the Selection of Shipping Lines within the Maritime Transport Market in Vietnam
INTRODUCTION: Selecting suitable shipping lines is crucial for supply chain efficiency, particularly in Vietnam’s maritime sector. OBJECTIVES: This study seeks to identify and prioritise key criteria affecting shipping line selection from the perspective of freight forwarders. METHODS: The Fuzzy Analytic Hierarchy Process (FAHP) was applied to evaluate multiple decision-making factors. RESULTS: Competitive freight rates, container availability, and special cargo capabilities were ranked as the most influential criteria. CONCLUSION: Findings highlight the need for carriers to enhance service reliability and cost-efficiency to meet the demands of developing markets.
Copyright (c) 2025 Xuan-Hoang Anh Dang, Thuy-Trang Nguyen https://creativecommons.org/licenses/by-nc-sa/4.0
Production Scheduling for Hybrid Flow Shop Systems with Heterogeneous Parallel Machines and Integrated Work-in-Progress Inventory
To secure a larger market share in the dynamically evolving personalized market, enterprises must adopt more flexible production modes. One critical challenge in this context is the optimization of production scheduling within hybrid flow shop systems featuring heterogeneous parallel machines. In such systems, machines differ in capabilities, setup requirements, and processing speeds, and not all machines are qualified to process every job - adding complexity to scheduling decisions. This study proposes a multi-objective hybrid flow shop scheduling model that integrates both time and material flow considerations. The model is designed to minimize two key objectives: the minimum of the makespan and the Work-in-Progress (WIP) inventory, which together influence overall system efficiency and responsiveness. By leveraging the strengths of traditional scheduling strategies, the proposed approach supports better planning and execution under increasing demand conditions. A comprehensive scheduling model incorporating time and cost constraints is developed, and numerical experiments are conducted to validate its effectiveness. The results demonstrate that the proposed model significantly improves production efficiency, reduces operational costs, and increases adaptability to market variations. Furthermore, the study provides actionable insights for decision-makers in complex manufacturing environments, offering a scalable framework for dynamic scheduling optimization. These findings contribute to advancing research in production scheduling and support practical applications in industries seeking to enhance competitiveness through agile and cost-effective operations.
Copyright (c) 2025 Phong-Nhat Nguyen, Truong Pham-Nguyen-Dan, Quyen Le-Thi-Ngoc https://creativecommons.org/licenses/by-nc-sa/4.0
A Study on dyeing ability of cotton fabric 100% with naphthaquinone extracted from nipa coconut shells
Natural dyes are known widely thanks to friendly properties to environment as health protecting ability for human. In this study, naphthaquinone of nipa coconut shells extracted by the reflux method that created effectively. The influences of ratio of dye extract, temperatures and time of dyeing and types of mordants based on the color strength (K/S) and color difference (DE) were studied. Our study applies the methods of extracting colorants in ethanol solvent, dyeing on an infrared dyeing machine, Mesdan by the exhaust dyeing method, measuring color on an X-Rite Color i5 spectrometer machine, analyzing effecting parameters by CIELab popular color space, and measuring Fourier-transform infrared (FTIR) spectroscopy to evaluate the presence of naphthaquinone in dye extract and bonding on fabric, testing more scanning electron microscopy (SEM) to observe the surface of dyed samples clearly. As results, the Nipa fruticans shell extract can dye 100% cotton fabric with a color difference ∆E of 41.07 and a K/S color strength of 12.96 when dyed with 10% CuSO4.7H2O because of their complex formation with the colorant with cellulose. Color fastness to washing on dyed cotton samples according to the ISO 105 – C06 A1S and ISO 105-X12 standard were tested to clarify further impacts of mordants to dye ability.
Copyright (c) 2025 Hue Trinh Thi Kim, Thanh Quynh Le Song https://creativecommons.org/licenses/by-nc-sa/4.0
Cost Optimization for Electronic Waste Recovery in a Reverse Logistics Network
INTRODUCTION: The rapid advancement of science and technology has fueled the widespread adoption of electronic devices, ranging from semiconductors to complex electronic circuits. These devices, typically classified into large household appliances, IT and telecommunications equipment, and consumer electronics, have significantly enhanced both the quality of life and operational efficiency in businesses. However, the increasing volume of these electronics has introduced a major challenge: the effective management of electronic waste (e - waste). Without a well - designed system, the accumulation of e - waste can lead to severe environmental and public health consequences. OBJECTIVES: This study aims to address the pressing issue of e-waste by analyzing the costs associated with its processing and proposing an optimized reverse logistics network. Specifically, the primary goal is to design a system that not only reduces operational costs but also minimizes the environmental footprint associated with e - waste management. By leveraging advanced modeling techniques, the research seeks to provide a practical framework that can be adopted in both industrial and municipal settings. METHODS: To achieve these objectives, a Mixed - Integer Linear Programming (MILP) model was developed to represent the cost optimization problem associated with e - waste collection and recycling. The model incorporates various stages of the reverse logistics process, including collection, sorting, transportation, and final processing. Its solution was derived using CPLEX optimization software, which allowed for the identification of the most cost - effective network configuration. Sensitivity analyses were conducted to ensure the robustness of the proposed framework, enabling stakeholders to make informed decisions based on different scenarios and constraints. RESULTS: The MILP model produced an optimized solution that minimizes recovery costs while maximizing the retrieval of reusable components and materials. In addition, the study found that incorporating sustainability factors into the model significantly improved the overall efficiency of the reverse logistics network. The optimized configuration demonstrates the potential of a well - structured reverse logistics system to reduce processing expenses, improve resource efficiency, and encourage the reuse of valuable materials, ultimately contributing to a more circular economy. CONCLUSION: Improper disposal of electronic waste presents significant environmental and health risks, particularly during the mechanical and chemical treatment of circuit boards. By introducing an optimized reverse logistics model, this study offers a practical solution that reduces processing costs, promotes resource conservation, and supports long - term environmental sustainability. Moreover, the findings underscore the importance of integrating advanced optimization techniques into the design of e - waste management systems, paving the way for more sustainable and cost - effective practices.
Copyright (c) 2025 Chi Nguyen, Ivan Kristianto Singgih https://creativecommons.org/licenses/by-nc-sa/4.0
Evaluation of a 3D-Printed Exoskeleton for Reducing Lower Back Muscle Load in Tomato Greenhouse Applications
Lifting and carrying tasks are known to increase the risk of work-related musculoskeletal disorders, particularly in the lower back region. This study aims to evaluate the effectiveness of a 3D-printed prototyping exoskeleton (RPE) in reducing the strain on lower back muscles during the transport of fruit boxes in a tomato greenhouse. A 3D-printed exoskeleton was designed and tested, with participants performing tasks such as lifting, carrying, and lowering heavy objects on tomato farms. The evaluation involved comparing muscle activity with and without the exoskeleton intervention. Muscle activity data were collected from 15 participants, focusing on the erector spinae (ES), latissimus dorsi (LD), anterior deltoid (AD), and medial deltoid (MD) muscles. The results demonstrated that using the exoskeleton significantly reduced the load on back muscles by 55.65% to 63.55% during lifting. Additionally, during carrying tasks, the exoskeleton reduced the load on the anterior deltoid muscle by 7.00% to 8.61%. The RPE also effectively decreased rectus femoris activity during dynamic lifting and carrying tasks, potentially alleviating pain and discomfort and reducing the risk of developing back-related disorders.
Copyright (c) 2025 Dang Khanh Linh Le https://creativecommons.org/licenses/by-nc-sa/4.0
An Aerodynamic Performance Analysis of E387 and S1010 Turbine Blade Profile
This paper investigates the changes in lift and drag coefficients, as well as the lift-to-drag ratio, of two airfoils designed for small wind turbines operating at low Reynolds numbers. The results include 2D simulations performed using the commercial software ANSYS Fluent 2019. The two selected airfoils, EPU-E387 and EPU-S1010, are newly developed and have not yet been studied for their aerodynamic performance. The research method involves varying the angle of attack to determine the optimal angle and identify which airfoil offers greater stability. The Reynolds numbers applied in the 2D simulations include 50,000, 60,000, 90,000, and 120,000. The simulation results indicate that the EPU-E387 airfoil achieves the highest lift-to-drag coefficient at the optimal angle of attack, which is 13.13% greater than that of the EPU-S1010 airfoil at Reynolds number 120,000. Additionally, the EPU-E387 airfoil demonstrates greater stability compared to the EPU-S1010 at higher angles of attack.
Copyright (c) 2025 Thi Tuyet Nhung Le https://creativecommons.org/licenses/by-nc-sa/4.0
Influence of Magnetic Fields on the Microstructure and Mechanical Properties of MIG Welds
This study investigates the impact of magnetic fields on the microstructure and mechanical properties of Metal Inert Gas (MIG) welds. Steel plate samples were welded under the influence of a magnetic field generated by permanent magnets, with simulations and experimental analyses used to evaluate weld quality. Key parameters such as magnetic field strength, magnet rotation speed, and distance were varied to assess their effects on the weld structure. The results revealed that applying a dynamic magnetic field improves weld penetration, alters grain structure, and reduces defects, enhancing mechanical strength and weld integrity. Finite element modeling was employed to simulate the effects of rotating magnets on the welding area, showing a uniform temperature distribution and significant changes in the fluid flow of the molten pool. These findings provide insights into optimizing welding parameters and demonstrate the potential for using magnetic fields to enhance welding processes, offering practical applications for advanced manufacturing.
Copyright (c) 2024 Thanh Phong Nguyen, Phat Dat Huynh, Quang Thanh Le, Thanh Long Bui, Tan Nam Le https://creativecommons.org/licenses/by-nc-sa/4.0
Optimizing Casting Processes with Rotating Magnetic Fields: Influence on Metal Solidification and Microstructure Homogeneity
This study explores the effect of rotating magnetic fields on the quality of casting low-carbon steel. Magnetic casting influences the molten metal flow through a controlled permanent magnetic field, which optimizes heat dissipation and induces fluid stirring within the mold. Our simulations reveal that a rotating magnetic field can enhance crystal fragmentation and improve microstructure homogeneity by inducing a vortex in the superheated region of the molten metal. The impact of variables, including the distance and magnetic flux density of the permanent magnet, was analyzed, showing their influence on the molten metal flow and casting outcomes. Experimental results, supported by modeling, highlight that higher magnetic flux densities contribute to a more uniform microstructure. This approach can refine casting processes, reduce defects, and promote structural consistency. Our findings offer valuable insights for optimizing magnetic-assisted casting technologies for enhanced metal solidification and improved casting quality.
Copyright (c) 2024 Quang Thanh Le https://creativecommons.org/licenses/by-nc-sa/4.0
A Comparative Review of Air Quality in India’s Most Populated Capitals: Analyzing AQI Based on Environmental pollutants PM2.5, Carbon Monoxide (CO), Nitrogen dioxide (NO2), Sulfur dioxide (SO2), and Ozone (O3)
Air pollution in India has become a significant environmental and public health issue, particularly in densely populated urban centers. This paper reviews and compares the Air Quality Index (AQI) in five of India's most populous and polluted capital cities—New Delhi, Mumbai, Kolkata, Chennai, and Bengaluru—focusing on key pollutants: Particulate Matter (PM2.5 and PM10), Carbon Monoxide (CO), and Sulfur Dioxide (SO₂). Data for this review were sourced from the Central Pollution Control Board (CPCB), WHO reports, and city-level environmental monitoring agencies. (1) Each city's AQI trends are analyzed to highlight the major contributors to air pollution, such as vehicular emissions, industrial activities, and seasonal factors like stubble burning and weather patterns. New Delhi consistently ranks as the most polluted city with hazardous PM2.5 and PM10 levels, while other cities like Mumbai and Chennai, though polluted, exhibit lower AQI levels due to geographical and climatic conditions. This review also examines the health risks posed by prolonged exposure to these pollutants and evaluates current mitigation efforts by the government. The study emphasizes the need for more stringent policies, sustainable urban planning, and public awareness campaigns to reduce air pollution in these urban areas. Further research is recommended to assess the long-term impact of current policy measures and explore alternative solutions for improving urban air quality.
Copyright (c) 2024 jaspreet https://creativecommons.org/licenses/by-nc-sa/4.0
Usability Assessment of Diesel Blends with Vegetable Oil and Ethanol in Diesel Engines
Vegetable oil is a type of biofuel that is renewable and capable of reducing emissions and harmful components in diesel engine exhaust. However, vegetable oil has several properties that differ from mineral diesel, such as high viscosity and large surface tension, making it unsuitable for direct use in conventional diesel engines. To overcome these drawbacks, several solutions have been proposed, such as pyrolysis, blending, esterification, and emulsification. Among these, the method of blending vegetable oil with low-viscosity fuels is considered simple and highly feasible. This paper presents some research results on the technical characteristics and emissions of a diesel engine using a diesel-ethanol-vegetable oil blended fuel.
Copyright (c) 2024 Thu Hoang Van https://creativecommons.org/licenses/by-nc-sa/4.0
An approach to determining garment sizes with fuzzy logic
This paper introduces a method for determining men's trousers sizes using a fuzzy logic technique. The Sugeno model is employed in a MISO fuzzy system with three inputs and one output. The process begins by choosing primary dimensions from the size chart, specifically one horizontal and one vertical dimension, followed by defining the value ranges for the membership functions. The model results, based on a size chart that includes six different dimensions. In this study, waist girth and outseam are selected as the primary dimensions, acting as input variables for the simulation model. Fuzzy logic is utilized to determine the size based on the Min-Max rule, with the IF-THEN structure effectively implementing commands within this model. The result of this process is an optimal size selection that aligns more accurately with the individual's body measurements. Moreover, the application of fuzzy logic significantly reduces the time required for size determination compared to traditional methods. This approach offers an alternative method for size selection, one that accounts for the inherent variability in body measurements, thus providing a more tailored and accurate fit for consumers. The study underscores the potential of fuzzy logic to enhance the efficiency and effectiveness of garment sizing systems, offering a promising solution to the challenges posed by standardized sizing methods.
Copyright (c) 2024 Mong Hien Nguyen https://creativecommons.org/licenses/by-nc-sa/4.0