Journal of Engineering and Innovation

Influence of size and epoxy imperfections on vibration in HDD actuator arm

2025-05-01T12:30:50+07:00

This research studied the effects of the thickness, length, and air bubbles in the epoxy of the HDD actuator arm on vibration to analyze the factors that caused the epoxy to fracture due to vibration. The HDD actuator arm model was developed using finite element software (ANSYS program) to achieve a percentage error from the PSV400 test of less than 8%. Subsequently, the thickness, length, and air bubbles in the epoxy of the HDD actuator arm were adjusted. The results demonstrated that the HDD actuator arm model had a maximum error of 7.827% from the PSV400 test. Regarding the adjustments to the thickness, length, and air bubbles in the epoxy, it was found that these factors did not affect the natural frequency in the arm mode shape but had a significant impact on the coil mode shape. Reducing the thickness and length of the epoxy decreased the natural frequency in the coil mode shape. Conversely, increasing the length of the epoxy increased the natural frequency in the coil mode shape. The presence of air bubbles in the epoxy resulted in a decrease in the natural frequency in the coil mode shape, with vertical air bubbles causing a more significant reduction than horizontal air bubbles.

Application of six sigma to prevent accident in manufacturing processes: a case study of a ceramic manufacturing plant

2025-04-27T16:41:27+07:00

This research aims to apply DMAIC methodology of Six Sigma to reduce accidents in the manufacturing process, focusing on data analysis within the context of a case study factory and promoting employee participation in problem identification and solution proposal. The research methodology begins with collecting accident data from the past three months and prioritizing it using Pareto charts. Subsequently, root cause analysis is conducted using Fishbone diagrams and failure mode and effects analysis (FMEA). Solution approaches are grouped using Affinity diagrams, and results are evaluated using Individual-Moving Range charts (I-MR Chart). After six months of improvements, the research results show a significant reduction in project indicators, with accident rates decreasing by 25.89%, accident-related downtime reducing by 25%, accident-related costs declining by 31.42%, and the Risk Priority Number (RPN) decreasing by 37.86%. The study concludes that the application of DMAIC methodology of Six Sigma and DMAIC can effectively reduce risks and enhance safety in manufacturing environments, through systematic data analysis, employee engagement, and the selection of tools appropriate to the organizational context.

Prototype development of an autonomous monorail system for document transportation between buildings

2024-12-17T10:10:49+07:00

Transporting documents between buildings is traditionally accomplished using vehicles, which results in energy waste and pollution. Moreover, the delivery of urgent documents outside the regular schedule necessitates staff involvement, thereby disrupting their regular duties. This research presents the development of a prototype tram system specifically designed for document transport between buildings. The system features a single-track design, facilitating easy installation in confined spaces. The electric trams are governed by algorithms that allow for real-time commands and tracking through wireless technology. The drive system employs a closed-loop Proportional-Integral (PI) controller to maintain the desired speed profile. Experimental results demonstrate that the vehicle can be effectively controlled wirelessly and adheres to the prescribed speed profile, both with and without a load.

Application of the D-optimal design of experimental for determining parameters in compression molding of banana leaf cup containers

2025-06-21T14:16:55+07:00

This research aims the optimal forming parameters for producing cup-shaped containers from banana leaves using the thermoforming process. The study focuses on three main conditions: the number of banana leaf layers, forming temperature, and forming time. A D-optimal experimental design was applied to reduce the number of experimental runs while ensuring analytical reliability. The effects of these parameters on the mechanical strength and water absorption of the containers were analyzed. The experimental results indicate that the optimal forming parameters comprises four layers of banana leaves, a forming temperature of 140 °C, and a forming time of 2 minutes. Under this setting, the containers achieved an average compression strength of 9.12 kN and a water absorption rate of 15.02%. Compared with commercial molded pulp containers, which showed an average strength of 13.61 kN and water absorption of 16.63%, the banana leaf containers exhibited statistically significant differences as confirmed by a two-sample t-test at the 95% confidence level. Although the banana leaf containers showed lower compression strength, the values remained within the requirements of ISO 3037:2022 (minimum 8 kN), and their water absorption met the criteria of ISO 535:2014 (not exceeding 17%). These findings support the suitability of banana leaf containers for practical applications and highlight their potential as biodegradable and environmentally sustainable packaging alternatives.

Analysis of Thai food topics from Youtube transcripts using LDA and NMF techniques

2025-05-23T11:51:21+07:00

This study aims to analyze the views of international users on Thai food through the transcripts in YouTube videos by comparing the performance of Latent Dirichlet Allocation (LDA) and Non-negative Matrix Factorization (NMF) techniques in identifying Thai food-related topics. Data was collected from 352 YouTube videos published between 2010-2024, data preprocessed, and transformed into N-Grams before analysis. The results revealed that LDA achieved optimal performance with the highest coherence score of 0.794 at 5 topics: (1) ingredients and food flavors, (2) tourism and food experiences, (3) Thai food components, (4) street food and popularity, and (5) cooking processes and ingredients. Meanwhile, NMF yielded optimal results with the highest coherence score of 0.956 at 8 topics: (1) seafood ingredients and flavors, (2) taste preferences, (3) street food culture, (4) Thai curry components, (5) dining experiences and food flavors, (6) food exploration, (7) rice and meat dishes, and (8) restaurant experiences and service. From the overall results of both techniques, international users perceive Thai food in four main dimensions: distinctive flavors, specific ingredients, dining experiences, and environmental context. Comparing both techniques, LDA excelled in showing connections between Thai food components through keyword overlap but had limitations in distinguishing subtopics. Meanwhile, NMF demonstrated superiority in identifying specific topics but lacked connections between them. The choice of technique should depend on the intended application, and combining results from both techniques may provide the most comprehensive perspective for developing strategies to promote Thai food internationally.

Improvement of สaminate production line with lean concept

2025-04-27T16:54:31+07:00

This research aimed to apply Lean concepts to reduce waste and improve production efficiency in a laminated glass manufacturing factory facing issues with meeting customer demand. The study employed tools such as the Value Stream Mapping (VSM), Yamazumi chart, and other Lean tools to identify bottlenecks and improve the production process. The results revealed that the cutting process incurred waste due to excessive transportation, while the lamination process experienced a bottleneck at the glass assembly stage. After improvement, the cutting time was reduced from 2.44 minutes to 2.12 minutes, a 19.51% reduction, and the glass assembly time decreased from 4.01 minutes to 3.07 minutes, representing a 22.47% reduction. These findings demonstrate that Lean implementation can enhance the factory's overall efficiency by reducing waste and improving processes. Specifically, the cutting process improved from 2,829 square feet per day to 3,514.9 square feet per day, an increase of 24.25%, while the glass assembly process improved from 1,612 square feet to 2,071.29 square feet, an increase of 28.49%.

Hybrid AHP and Fuzzy-TOPSIS methods in subcontractor selection: Case studies of government construction projects

2025-06-09T14:21:59+07:00

This study aims to develop criteria and a selection framework for subcontractors in the construction project of Uttaradit Hospital by applying the Analytic Hierarchy Process (AHP) in conjunction with the Fuzzy Technique for Order Preference by Similarity to Ideal Solution (Fuzzy-TOPSIS), referred to as AHP-FTOPSIS. The application of this method in the study helps mitigate issues in subcontractor selection through pairwise comparison and enhances the reliability of decision-making under constraints related to limited construction space. The approach emphasizes minimizing adverse impacts on health, safety, and the environment. The development of subcontractor selection criteria began with a literature review, identifying an initial set of 35 criteria, which were then narrowed down to 12 criteria. Subsequently, the evaluation process was conducted to assess three subcontractors, using input from three experts involved in the hospital construction project. The results indicated that Subcontractor 3 had the highest score at 0.6678, followed by Subcontractor 1 at 0.3620, and Subcontractor 2 at 0.3615, respectively. Moreover, this method enhances the accuracy of results by ensuring consistency in the questionnaire index and leveraging expert judgment in the evaluation process. The approach is not only applicable to subcontractor selection in construction projects but can also be adapted for other decision-making problems, such as supplier selection for raw materials and production or service processes.

AU self-balancing and tracking bicycle: implementation of design and control system

2025-02-08T11:27:28+07:00

The AU Self-Balancing and Tracking bicycle (AUBST) utilizes Proportional Derivative (PD) controllers to achieve robust self-balancing and tracking control for unmanned navigation. The system leverages the gyroscopic effect for balance control and integrates gyroscope and encoder sensors to measure lean angles, while GPS and a compass enable precise tracking. The balance system is implemented using a double-loop feedback mechanism, which incorporates additional sensors and optimally tuned gains to enhance performance. Experimental results demonstrate the superiority of the double-loop system, achieving a maximum lean angle of ±2◦ and minimal tracking error. These advancements enable AUBST to deliver reliable self-navigation and open avenues for practical applications, including urban commuting, autonomous delivery systems, safety awareness and mobility solutions for individuals with disabilities.

Application of ergonomic technique for work improvement of the I-beam production occupation

2025-08-01T14:57:23+07:00

The purpose of this research was to apply ergonomic techniques for work improvement of the I-beam production occupation. The researchers applied Rapid Entire Body Assessment (REBA) and Rapid Upper Limp Assessment (RULA) techniques to analyze the risk of 19 postures in the I-beam production. From the ergonomic evaluation using the both techniques, it was found that there were 11 high-risk postures and 8 moderate-risk postures. From the evaluation results, the researchers proposed guidelines for improving the works of the I-beam production by designing working tools, using assistive devices and adjusting work postures for reducing the risk and increasing the convenience of the workers. After the work improvement, the researchers conducted another risk analysis using the same two techniques. It was found that there were 11 working postures with lower risk values. This result led to work improvement and increase safety of the studied occupation’s working.

Study on the leakage behavior and concentration reduction of ammonia leakage using mechanical ventilation in the ammonia refrigeration machine room for tube ice factory

2025-09-18T11:50:42+07:00

Frequent leakage is observed in industrial refrigeration systems that use ammonia refrigerant. Respiratory toxicity and adverse health effects among large populations are caused by leakage accidents. Ventilation in emergency situations is prescribed by the Ministry of Industry’s regulations. Differences were identified when the requirements were compared with TIS and IIAR standards. The suitability of emergency ventilation for machine rooms in ammonia refrigeration systems was evaluated using a mathematical model. Leakage rates under transient conditions can be analyzed by the model in accordance with ACGIH ventilation principles. From the transient analysis, it was shown that the buildup of ammonia vapor concentration follows a characteristic time-dependent function. When the interplay between system pressure and leak size was examined, increasing system pressure was found to amplify the effect of a given increase in orifice size on the leak rate. The response speed of ammonia detectors is significantly affected by the buildup stage. During an emergency ammonia release, the purging stage is important so that hazardous concentrations are reduced more rapidly to allow a longer evacuation period and safety is improved. Purging time can be estimated and changes in ammonia concentration can be monitored through transient-state analysis and parameter adjustments. The purging time is affected by the initial concentration and by air-mixing conditions in the machine room. A longer purging time is required if the initial concentration is high or if air mixing in the machine room is poor. The purging time is affected by the air-change rate required for the emergency situation. If the air-circulation volume is high, the purging time can be significantly reduced. The dynamic simulation technique developed in this research is expected to serve as an efficient tool for analyzing time-varying ammonia concentrations and can be applied to machine rooms of different sizes. A machine room with a volume of 2,475 m³ was considered as the case study, under normal operating conditions and typical outdoor weather in Thailand. The time evolution of concentration from 0 to 50 ppm was primarily examined. (1) Buildup: When the leak-orifice diameter was increased from 1 mm to 4 mm, the leak rate was increased by a factor of 16. When the refrigeration-system pressure was increased from 1,400 kPa to 1,600 kPa at a fixed orifice size, the leak rate was increased by 35%. For the rise from 0 to 50 ppm, required times of 15.25, 6.77, and 3.81 s were obtained for orifice diameters of 2, 3, and 4 mm, respectively. (2) Purging: For initial concentrations of 35, 40, 45, and 50 ppm, the time required to reach 25 ppm was 1.68, 2.35, 2.94, and 3.47 min, respectively, when K = 2.5. When emergency ventilation of 30 ACH was applied to reduce the concentration from 35 to 25 ppm, times of 0.67, 1.01, and 1.68 min were obtained for K = 1, 1.5, and 2.5, respectively. For reductions from 35 to 25 ppm with emergency-ventilation rates of 3 (ministerial regulation), 10.8 (TIS), 20, 25, 30, 35, and 40 ACH, the required times were 16.82, 4.67, 2.52, 2.02, 1.68, 1.44, and 1.26 min, respectively.

A study of macroscopic pedestrian traffic flow by simulation experimentation of using mobile phone and rushed walking

2024-04-26T13:35:32+07:00

This article studies pedestrian traffic flow by simulating scenarios. Prior to experimentation, surveys were conducted within the pedestrian walkway of a subway station (MRT) to examine behavioral patterns expected to affect pedestrian traffic flow. These behaviors include hurry walking and mobile phone usage while walking. Subsequently, several scenarios were constructed to capture diversify behaviors including current scenarios with proportions from surveys, and scenarios with extreme proportions. Traffic flows were designed to vary in density from light to crowded. Analysis results were separated into two types: (1)comparing walking speeds between current and extreme scenarios revealed a statistically significant increase in average speed with an increase in the proportion of hurried pedestrians, while the average speed decreased significantly with an increase in the proportion of mobile phone users among pedestrians and (2) constructing Fundamental Diagram models revealed that the Northwestern model demonstrated the highest performance based on statistical criteria. This model can be used to forecast pedestrian traffic conditions or to design walkways for optimal efficiency, tailored to the flow behavior in the area.

Decision support system for economic crop planning using tree technique: A case study of Hua Ruea subdistrict, Mueang district, Ubon Ratchathani province

2025-10-14T12:43:27+07:00

This research aimed to develop a decision support system for planning the cultivation of economic crops using decision tree techniques and to evaluate the system’s performance in Hua Ruea Subdistrict, Mueang District, Ubon Ratchathani Province. The developed model aims to predict the suitable economic crop types (rice, cassava, sugarcane, corn) along with estimated yield (kg/rai) and net income (baht/rai) for each crop. The study employed a Research and Development (R&D) methodology, integrating both quantitative and qualitative approaches. The sample group consisted of 294 farmers, determined using Yamane’s formula, and 15 purposively selected experts. The system was developed using Python, Django, and PostgreSQL, with processing based on Decision Tree combined with Random Forest techniques. The research findings indicated that the developed system demonstrated high performance, achieving an accuracy of 88.5%, a precision of 87.2%, a recall of 86.9%, and an F1-score of 87.0%. After six months of real-world use, crop yield per rai increased by 20.5%, production costs decreased by 15.8%, net income increased by 25.4%, and return on investment (ROI) rose by 32.7%. User satisfaction was rated at a high level (4.4 out of 5.0). The developed decision support system effectively assisted farmers in making informed decisions regarding the selection of economic crops, resulting in significant statistical improvements in crop yield and farmers’ income.