Engineering and Technology Horizons

Improving Maintenance Operations on Raw Material Conveying Equipment by Using TRIZ Technique

Pawarit Siriwattanamethanon, Ruephuwan Chantrasa — Mon, 24 Jun 2024 00:00:00 +0700

The objective of this research is to improve equipment used for conveying raw material in the construction material industry and establish standard procedures for maintenance by applying Theory of Inventive Problem Solving (TRIZ). Research methodology consists of 1) studying the maintenance system of raw material conveying equipment of the case study company 2) collecting data and prioritizing problems using a Pareto chart, 3) setting goals, 4) analyzing the causes of the problems with Why-Why analysis and 3 GEN techniques, 5) concluding the results. Results from the study in 2022 showed that problem occurred at sieves and vibrator base used for filtering raw materials resulting in a high maintenance frequency of 28 times. The causes of the problem are the improper shape of the sieves and the installation position of the sieve vibrator including the carelessness of the worker to turn off the vibrator. This research solved the problems by applying TRIZ as guidelines for designing new sieves and applying Total Productive Maintenance (TPM) in establishing standard procedures for maintenance. The results of the improvement during May-November 2023 showed that the frequency of sieves maintenance decreased to 3 times equivalent to 6 times per year approximately, achieving the goal of less than 14 times/year. The MTBF increased from the original 171.67 hours to 1,055.91 hours and the MTTR decreased from 3.04 hours to 2.55 hours. It can be concluded that TRIZ can be applied to improve the material conveying equipment by significantly reducing the maintenance frequency.

Comparative Study on Flexural Behavior of Reinforced Concrete Beams Cast by Using Hydraulic Cement and Ordinary Portland Cement

Mon, 24 Jun 2024 00:00:00 +0700

This paper is a comparative study of the flexural behavior of reinforced concrete beams cast by using hydraulic cement and ordinary Portland cement for construction applications. The main variables used in this research comprise of type of cement, ultimate compressive strength of concretes, and curing time. Two different types of cement, including hydraulic cement and ordinary Portland cement, were used at three different ultimate compressive strengths of 18 MPa, 25 MPa, and 32 MPa with the curing times of 28 and 90 days. The beams' nominal span-to-depth ratio is 8.0. The results showed that the reinforced concrete beams cast by using hydraulic cement and ordinary Portland cement had similar flexural behavior and failure patterns. Both types of the reinforced concrete beams exhibit linear elastic behavior up to approximately 80–90% of their maximum applied load. Then, the behavior of the beams is nonlinear in that the deflection increased rapidly with a slight increase in the applied load until reaching their failure. In addition, based on the experimental results obtained from this study, it was found that the ACI design equations are acceptable for predicting the design strength of the reinforced concrete beams cast by using hydraulic cement and the hydraulic cement can be an equivalent substitute for ordinary Portland cement for the reinforced concrete beams used in this study. Therefore, this application of the hydraulic cement is not only the environmentally friendly practices, but also promoting low-carbon society as well.

Analyzing Factors Influencing the Development of Railway Freight Transportation Service through the Fuzzy Analytic Hierarchy Process Technique

Mon, 24 Jun 2024 00:00:00 +0700

The main objective of this study is to apply the Fuzzy Analytic Hierarchy Process (FAHP) technique to assess factors influencing the development of railway freight transportation services. These factors include four critical performance indicators within the supply chain: responsiveness, cost, reliability, and agility. Moreover, the study aims to develop guidelines for enhancing the effectiveness of railway freight transportation in Chiang Rai province, particularly through the Den Chai–Chiang Rai–Chiang Khong railway route. Data were collected from 9 experts, including logistics service providers, users, and academics then, pairwise comparisons of factors were conducted. The results revealed that the cost factor holds the highest significance at 33.86%, followed by reliability, responsiveness, and agility factors at 28.51%, 26.14%, and 11.49%, respectively. Consistent with satisfaction scores obtained from logistics service users, the cost factor holds the highest satisfaction score at 4.78, followed by reliability, responsiveness, and agility factors with scores of 4.41, 4.16, and 4.01, respectively. The result above will bring towards preparation in railway freight transportation of Chiang Rai province and encouraging entrepreneurs to shift to railway transportation mode in the end.

Factors Affecting User Satisfaction of Local Van (Songthaew): A Case Study of The Local Van (Songthaew) Route 1263 In Pattanakarn Road Soi 20, Bangkok

Chaturaphak Wichian, Jumrus Pitaksringkarn — Mon, 24 Jun 2024 00:00:00 +0700

The research aims to identify the factors affecting satisfaction and suggestions from users of local van (songthaew) route 1263. This will propose measures to manage the operations and improve level of satisfaction. The researcher has established a set of questionnaires for 400 random respondents and using Multiple Regression Analysis to determine the correlation between factors that affect satisfaction. Discover correlations between factors influencing satisfaction using Pearson Product Moment Correlation Coefficient. It was found that factors affecting user satisfaction of local van (songthaew) route 1263 in Pattanakarn road soi 20 by the average satisfaction score of the factors that affect satisfaction (Y₁) would be management (X₁), physical aspects of vehicles (X₂), service (X₃), safety (X₄) and environment (X₅). The equation of predicting satisfaction is Y₁ = -2.164E-15 + 0.148 X₁ + 0.333 X₂ + 0.259 X₃ + 0.148 X₄ + 0.111X₅ The variables can predict the overall satisfaction (Y₁) with adjusted R-Square all four factors have equivalent to 1.000 for accuracy (100.0%), the relationship between variables is equal to 1.000. The above equation shows the overall satisfaction across all with an average predictive value (Predicted Y₁) of 3.28 (moderate satisfaction). There is a correlation (Pearson Correlation) among there five factors and their satisfaction in the order of the relationship as follow: service (r = 0.764), safety (r = 0.739), environment (r = 0.638), physical aspects of vehicles (r = 0.236) and management (r = 0.058) a significant relationship except for management. The top three additional suggestions from users are installation of GPS systems on the local van (songthaew) route 1263 for convenient passenger tracking (23.0%), decreasing the running time (15.5%), and repairing damaged seats (14.5%). Prioritizing the bus operations management and safety regulations must be established by relevant governmental agencies to promote customer satisfaction. Vehicle examinations must strictly adhere to substantial practices. Operators should receive training on safe driving and outstanding service to boost passenger confidence and service. User suggestions regarding the management are, for example, an appropriate schedule and bus operation punctuality. There should be collaboration between government agencies and the private sector in order to accommodate passengers on main public transportation while connecting with local ones. A public hearing among stakeholders from both the private and governmental sectors should be held in order to gain ideas for improvement, such as fare promotion. Customer satisfaction will be improved if the above measures, along with all other recommendations, are taken into serious consideration by the operator and government agencies.

Optimization of Brazing Parameters for 316L Stainless Steel with AgCuZn Filler Metal Under Argon Atmosphere

Mon, 24 Jun 2024 00:00:00 +0700

This research studies the optimal parameters for brazing 316L stainless steel using AgCuZn as filler metal under an argon gas atmosphere. The brazing parameters included temperature, brazing time, and argon gas flow rate. The study employed Box-Behnken design for experimental design and desirability function as the optimization tool. Mechanical properties study included the measurements of shear force, microhardness, microstructure, and fracture of brazing joints through a scanning electron microscope (SEM) as well as the chemical composition using an energy dispersive x-ray spectroscopy (EDS). As a result, the temperature and the brazing time significantly affected the shear force of the brazed joint at a 95 percent confidence interval. The optimal condition of the study was 800°C of temperature and a 20-minutes brazing time which caused the maximum shear force at 5,909.1 N. The brazing joint strength was increased when the temperature and time of brazing were increased and reached the optimal point. Microstructure showed a formation of an Ag-rich phase, a Cu-rich equiaxed dendrite phase, and a eutectic Ag-rich phase, which completely combined as the network structure and evenly small fine grains. Moreover, the shear force of the brazed joint was decreased when the temperature and time of brazing exceeded the optimal point due to the grain growth of the interface layer.

Optimum Weight Parameter of Weight Centroid Method for Indoor Positioning in Environment with Different Path Loss Exponent and Multipath Fading Effect

Pichaya Supanakoon, Monchai Chamchoy — Mon, 24 Jun 2024 00:00:00 +0700

This paper proposes optimum weight parameter of weight centroid method for indoor positioning in environment with different path loss exponent and multipath fading effect. The indoor environment is defined as square with each side 10 m long. There is a transmitter installed in the center of each side. The distance error model is applied to calculate the distances between the location coordinates of user and the location coordinates of transmitters in environment with different path loss exponent and multipath fading. The total 100 location coordinates of user are estimated by using weight centroid method, varying weight parameter in the range of 1 to 10. The optimum weight parameter is defined as the case where mean of distance error of all positions is the least. The optimum weight parameter for environment with different path loss exponent and multipath fading effect is illustrated. The results show that the optimum weight parameter changes slightly with the path loss exponent and tends to change with the standard deviation of the multipath fading effect divided into 3 periods. The first period tends to increase slowly, the second period tends to increase rapidly, and the third period tends to fluctuate up and down. Moreover, the size of the indoor environment has very little impact on the optimum weight parameter. These results make it possible to select optimum weight parameter for case with path loss exponent and standard deviation of multipath fading effect that match or are close to the channel of indoor environment.

Design and Control of Two-Serial-Link Piezoelectric Manipulator

Krit Maieam, Nyesunthi Apiwattanalunggarn — Mon, 24 Jun 2024 00:00:00 +0700

This paper describes a methodology for modeling, system identification, and designing a controller of a two degrees-of-freedom manipulator made from piezoelectric material. A piezoelectric bimorph is composed of two piezoelectric ceramic plates bonded to a brass plate which is sandwiched between the piezoelectric plates. One piezoelectric bimorph is attached perpendicularly to the other bimorph to form the manipulator. The manipulator is modeled using the finite element method. A reduced order model of the manipulator is obtained through modal analysis. The reduced order model is used to design closed-loop feedback controllers based on the exact feedback linearization (1) to regulate a tip of the manipulator to a set point or (2) to make the tip to track a desired signal. The closed-loop control manipulator can accomplish the tasks with satisfied results.

Development of Differential Evolution Algorithm for Simple Assembly Line Balancing Problem Type 1

Krit Chantarasamai, Visit Junchuan, Poontana Sresracoo — Mon, 24 Jun 2024 00:00:00 +0700

The Simple Assembly Line Balancing Problem Type 1 (SALBP-1) is a widely embraced method in the industry for its simplicity in organizing production processes and enhancing efficiency. Consequently, a Differential Evolution Algorithm (DDE) using a backward task sequence was developed in this study to assist in production process management by determining the optimal number of stations. The efficacy of this method was assessed by juxtaposing it with heuristic approaches, including Longest Operation Time (LOT), Most Following Tasks (MFT), Ranked Positional Weight (RPW), Shortest Operation Time (SOT), Fewest Following Tasks (FFT), Ant Colony Optimization (ACO), Differential Evolution (DE), and Immune Genetic Algorithm (IGA). The findings reveal that DDE outperforms LOT, MFT, RPW, SOT, and FFT in discovering superior solutions and consistently matches solutions achieved by ACO, DE, and IGA methods across all problems. Notably, the DDE method exhibits a shorter time frame for solution discovery.

Logistic Regression Analysis of Factors Affecting Robot Arm Movement Testing

Nichanach Katemukda — Mon, 24 Jun 2024 00:00:00 +0700

Currently, with the rapid growth of robots in the industrial and service sectors, the robotic arm product is in high demand, and manufacturers need to deliver it on time. The manufacturer has a new product called “robot arm”. The issue is a high failure rate at the test station called the robot arm movement test. The manufacturer focused on the test process in order to reduce any variance that may result in a failure rate, with the operator's performance being their primary interest. Since the first group was built and tested, totaling 233 units of the robot arm, the logistic regression was applied with three independent variables. There are operators, working shifts, and product models. The results indicate day or night shifts are not related to the test failing. The operator and product model are important factors in the test failing. The 1.5–meter–long model has a higher chance of passing the test than the 1–meter–long model by about 13.66 times and the 2–meter–long model by 25.25 times. Operator D is the best at performing the robotic arm test and has a better chance of passing than the other operators (2.07 times for Operator A, 6.53 times for Operator B, and 7.01 times for Operator C). The action is that the software test needs to be updated for the 1– and 2–meter–long models. Moreover, Operators B and C need to be retrained as a priority. Then the manufacturer needs to focus more on the assembly process for yield improvement.

Analysis and Design Approaches for the Transition Zone between Bridges and Embankments in Railway Tracks

Wichain Sommanawat, Surasak Niyompanitpattana — Mon, 24 Jun 2024 00:00:00 +0700

This study presents an analysis of stability improvement methods for the transition zone between bridge structures and embankments in railway systems using the Finite Element Method (FEM) model. The study aims to provide guidelines for designing such transition zones. The three methods investigated are recommended by the International Union of Railways (UIC) standard 719R: 1. Société Nationale des Chemins de fer Français method (SNCF), 2. Magyar Államvasutak method (MAV), and 3. Deutsche Bahn method (DB). Initially, the interaction between the rail and bridge models was calibrated using the E1-3 case from the UIC 774-3, which yielded results close to the reference values. Additionally, it was found that analyzing the sequence of applied loads provides better results than directly combining the responses from each load type. Subsequently, the study examined the stability improvement of the transition zones using the rail properties from the UIC 54 and the load standards from U20, which are applicable in Thailand. The analysis revealed that all three methods effectively reduced settlement in the transition zone, with the DB method achieving the highest reduction at 36.18%, and the SNCF and MAV methods achieving an equal reduction of 32.89%. However, considering both settlement reduction and construction techniques, the SNCF method is recommended as the most suitable approach for the design and construction to improve the stability of transition zones.