KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/123456789/1

Browse

Search Results

Now showing 1 - 10 of 26

Some of the metrics are blocked by your
consent settings
Modeling Equivalent Circulating Density During Drilling Operations in the Gulf of Thailand
(2026-03-31)
Leerojanaprapa, Kanogkan
;
Suttaloon, Sudarat
;
Bhundarak, Komn
;
Sirikasemsuk, Kittiwat
Equivalent Circulating Density (ECD) represents the total hydrostatic pressure generated by drilling fluid while in motion. This prevents the internal pressure within the well from exceeding the fracture resistance of the rock, which could lead to lost circulation and an inability to effectively control the wellbore pressure. This research aims to predict ECD in 6.125-inch production section in Gulf of Thailand field by using five machine learning algorithms were utilized, namely Support Vector Machine (SVM), Random Forest (RF), Artificial Neural Networks (ANN), Gradient Boosting (GB), and Extreme Gradient Boosting (XGBoost). Various sensors from the Measure While Drilling (MWD), Logging While Drilling (LWD), and Pressure While Drilling (PWD) tools were used to collect raw data, totaling 38,863 records and 24 variables to predict the ECD value. The dataset was randomly split into 80% for training and validation and 20% for testing. The results indicate that the RF technique outperformed the other models in predicting ECD values, producing the lowest RMSE of 0.031. Therefore, the RF model is most suitable for further development and real-time application in predicting ECD values.
Some of the metrics are blocked by your
consent settings
Analysis of Rear Differential Component Clustering in Transmission Systems Using Hierarchical Cluster Analysis with and without Procurement Strategy Matrix Variables
(2025-04-01)
Sombunsook, Saowalak
;
Sirikasemsuk, Kittiwat
;
Leerojanaprapa, Kanogkan
The automotive industry has faced significant challenges due to the large number of Tier 2 suppliers for Rear Differential components, with 17 suppliers providing 32 different parts. This situation has resulted in increased production costs and more complex supply chain management. This study aimed to analyze the clustering of Rear Differential components in transmission systems using Hierarchical Cluster Analysis, with the goal of supporting cost reduction in the automotive industry. Two clustering models were compared: Model 1, which excluded procurement strategy matrix variables (Special Requirements, Raw Material Grade, Raw Material Type, Manufacturing Process, Tier 2 Supplier Information, and Company Location), and Model 2, which incorporated an additional variable related to the Procurement Strategy Matrix. The decision criteria for determining the optimal number of clusters were based on four key factors: 1) Product design, 2) Characteristics, 3) Materials, and 4) Manufacturing. The clustering results for both models revealed the same optimal number of 13 clusters; however, the similarity matrix between the clusters differed. Furthermore, the number of members within each cluster varied. Based on the criteria for determining the optimal number of clusters, Model 2, which included the Procurement Strategy Matrix variable, demonstrated superior clustering efficiency compared to Model 1. Ultimately, this research identified 13 optimal clusters, reducing the number of Tier 2 suppliers from 17 to 13, representing a 23.53% reduction.
Some of the metrics are blocked by your
consent settings
Work posture risk comparison of RULA and REBA based on measures of assessment-score variability: A case study of the metal coating industry in Thailand
(2024-01-01)
Sirikasemsuk, Kittiwat
;
Kittipanya-Ngam, Pichawadee
;
Luanwiset, Darin
;
Leerojanaprapa, Kanogkan
This study examines the work posture risk comparison of RULA and REBA based on measures of assessment-score variability. During the metal coating process, chemicals were frequently employed, necessitating a heightened level of caution among the employees. The Cornell Musculoskeletal Discomfort Questionnaires (CMDQ) revealed the manifestation of physical discomfort among employees. In this study, the rapid upper limb assessment (RULA) and the rapid entire body assessment (REBA) were used to identify ergonomic concerns related to the work of employees in the black oxide coating department of a metal coating firm. The sensitivity of risk assessment between the two methods was investigated, considering the mean and variability of the assessment scores. Consideration was given to the diverse and crucial work positions of employees at each station, focusing exclusively on the standing working posture. In the black oxide coating section, there were 12 steps that 20 workers had to complete. Under the same wo rking postures, the overall average RULA score was determined to be at a high-risk level, whereas the overall average REBA score was at a moderate-risk level. As a result, the RULA method had a greater capacity for risk warning than the REBA method. Levene's test was also applied to determine whether the variances of the risk scores computed using the two techniques were equal. The results of the analysis showed that the variances in the scores using the two methods were not significantly different.
Some of the metrics are blocked by your
consent settings
Navigating online learning challenges and educational infrastructure in times of crisis: Insights and solutions among Thai engineering students utilizing a mixed-methods analysis
(2024-01-01)
Sirikasemsuk, Kittiwat
;
Leerojanaprapa, Kanogkan
;
Khwanpruk, Kankanit
The rapid shift to online learning during COVID-19 posed challenges for students. This investigation explored these hurdles and suggested effective solutions using mixed methods. By combining a literature review, interviews, surveys, and the analytic hierarchy process (AHP), the study identified five key challenges: lack of practical experience, disruptions in learning environments, condensed assessments, technology and financial constraints, and health and mental well-being concerns. Notably, it found differences in priorities among students across academic years. Freshmen struggled with the absence of hands-on courses, sophomores with workload demands, and upperclassmen with mental health challenges. The research also discussed preferred strategies for resolution, emphasizing independent learning methods, managing distractions, and adjusting assessments. By providing tailored insights, this study aimed to enhance online learning. Governments and universities should support practical work, prioritize student well-being, improve digital infrastructure, adapt assessments, foster innovation, and ensure resilience.
Some of the metrics are blocked by your
consent settings
Improving Automotive Tire Defect in the Vulcanization Process by Leakage Bladders Issues
(2024-01-01)
Kiatcharoenpol, Tossapol
;
Sawangnimitkul, Penpisut
;
Junmewong, Rattanaporn
;
Sirikasemsuk, Kittiwat
The primary objective of this project is to minimize defects in industrial tires resulting from issues with leaking bladders during the curing process. The project aims to reduce the current monthly defective tire production of 1,378.70 kilograms to a target of 1,240.83 kilograms per month, which represents a 10% reduction in defects. Utilizing the QC story methodology, QC 7-tools, and Quality Control techniques, a thorough examination of data and root cause analysis identified five significant factors contributing to defective tires caused by bladder leakage. These factors include 1) a lack of expertise in bladder inspection, 2) excessive usage of bladders, 3) contaminations on the bladder surface, 4) inadequate bladder lubrication and 5) oxidation occurring inside the bladder. To address these issues, a new operational procedure and training program were introduced, alongside modifications to the curing machine to mitigate the oxidation process. Over a span of two months, these changes resulted in a reduction in defective tires to 735.345 kilograms per month, equivalent to a 46.66% decrease in the problem, and a cost savings of 10,000 USD per year.
Some of the metrics are blocked by your
consent settings
Solving the incomplete data problem in Greco-Latin square experimental design by exact-scheme analysis of variance without data imputation
(2024-01-01)
Sirikasemsuk, Kittiwat
;
Wongsriya, Sirilak
;
Leerojanaprapa, Kanogkan
This study introduced a novel exact-scheme analysis of variance to tackle the challenge of incomplete data within the Greco-Latin square experimental design (GLSED), specifically for scenarios with a single missing observation across any treatment and block level, thus eliminating the need for conventional data imputation methods. This approach innovatively addresses and mitigates the bias in the treatment sum of squares, a significant drawback of traditional missing plot techniques, by providing a precise, exact-scheme-based formula for calculating the treatment sum of squares in fixed-effect GLSED contexts with unrecorded values. Moreover, it offers a method for correcting biased treatment sum of squares values, presenting an adjustment mechanism for instances where the least squares method was previously employed to estimate missing values. This comprehensive strategy not only enhances the methodological accuracy and integrity of GLSED studies but also contributes significantly to the field by offering a solution to navigate the complexities of incomplete datasets without resorting to data imputation, thus improving the rigor and validity of experimental designs in the face of missing data challenges.
Some of the metrics are blocked by your
consent settings
Simulating the Impact of Defective Rates on the Bullwhip Effect in a Supply Chain: A Reciprocating Compressor Manufacturing Case Study with Exponential Smoothing Forecasting
(2024-01-01)
Rattanapuchong, Pradthana
;
Sooksaksun, Natanaree
;
Sirikasemsuk, Kittiwat
This study was dedicated to simulating the impact of defective rates on the bullwhip effect within the context of a supply chain, with a specific focus on a case study involving reciprocating compressor manufacturing. The supply chain configuration encompassed a distributor, a factory, customer, and a remanufacturer. Customer demand was forecasted utilizing the exponential smoothing method, while an order-up-to inventory policy was implemented. The results unveiled a direct correlation between an increase in defective rates and a heightened bullwhip effect. Moreover, the study demonstrated that an elevation in the average yield rate corresponded to a mitigation of the bullwhip effect.
Some of the metrics are blocked by your
consent settings
Optimization of Process Conditions for Hard Disk Drive Assembly for Defect Reduction
(2023-11-01)
Sirikasemsuk, Kittiwat
;
Leerojanaprapa, Kanogkan
A spoiler installed in a hard disk drive can reduce the airflow velocity that causes vibration at an actuator arm and its head. In the case study, a hard disk drive manufacturer identified the defect of a loosely tightened spoiler in the hard disk drive by the spoiler installation machine. This occurred as a result of incorrect screw spacing (also called ‘the screwdriver encoder’). There was no study that specifically specified or created a suitable relationship model between the screwdriver encoder and associated parameters for the installation of a spoiler. Factors affecting the screw spacing were determined using multiple regression analysis, and a mathematical model of the significant factors of the screwdriver encoder was built. Data were collected from the spoiler installation machine and its software. Four factors were identified with the potential to impact the screwdriver encoder as (1) vacuum level for picking up the screw, (2) time spent in tightening the screw, (3) bit angle, and (4) screw torque. The ANOVA results pointed out that the screw torque within the range of experimental values did not affect the screw spacing, and a quadratic regression model was the most appropriate under various statistical criteria. This research demonstrated that a sophisticated regression model, i.e., a cubic model, is not always a good choice for an agent. In addition, the optimal values for the spoiler installation machine were determined. The faults decreased by 0.0096% from 0.055% each month. For choosing the relationship model of additional workpiece screw tightening variables, this research phase can be utilized as a guideline.
Some of the metrics are blocked by your
consent settings
Applying Lean Concept and Software Packages to Support Critical Issue Monitoring Process in Office
(2023-03-31)
Kittipanya-Ngam, Pichawadee
;
Chanthavutti, Anunya
;
Sirikasemsuk, Kittiwat
The purpose of this research was to improve the performance monitoring process of critical issues in a case study company. The problem was that the process of tracking the performance of critical issues was ineffective. This research applied the lean concept. We started with the study and analysis of the work in order to find the root causes of the problem by means of the fishbone diagram. Subsequently, ECRS techniques were used to improve activities. The researcher used Microsoft Office 365 platforms, i.e., Microsoft Planner, to track the performance of the important tasks. After work process improvement, the activities 1 (the coordinator of the five departments collected the department forms) and 4 (the central coordinator summarized the forms of the five departments into the agency's form) could be reduced. Finally, the wasteful process time was reduced by more than 50 %. Also, the workload of coordinators was greatly reduced.
Some of the metrics are blocked by your
consent settings
Measuring the Efficiency of Thai Commercial Banks during the COVID-19 Pandemic by Data Envelopment Analysis
(2022-08-26)
Leerojanaprapa, Kanogkan
;
Bhundarak, Komn
;
Atthirawong, Walailak
;
Sirikasemsuk, Kittiwat
This study intends to measure the comparative efficiency of Thai Commercial Banks. The performance data has been collected over the past 2 years, between 2020 and 2021 during the COVID-19 pandemic and then compared to performance during the normal period of 2017-2018. Data Envelopment Analysis (DEA) using Variable Return to Scale (VRS) is applied to measure banking performance. Through Intermediation Approach, specific input variables are considered: employee expenses, directors' remuneration expenses, premises and equipment expenses and deposits. The output variables, including loans to customers and investment, are also analyzed.The same time, through the Production Approach, these specific input variables are analyzed: employee expenses, directors' remuneration expenses, premises and equipment expenses, fees and service expenses, taxes and duties and interest expenses. The output variables, including interest income, fee and service income, deposit, and loans to customers, are used to analyze the efficiency. The results of analysis with the Intermediation Approach indicate 5 of 13 Thai Commercial Banks were considered relatively inefficient including BAY, BBL, KBANK, SCB and SCBT. In addition, CIMB is 1 of 13 Thai Commercial Banks is considered as relatively inefficient under the Production Approach.

KMITL

Browse

Filters

Settings

Sort By

Results per page

Search Results