Engineering Journal of Research and Development

APPLICATION OF STANDARD TIME FOR HALF- RED BRICK WALLING INSTALLATION USING DIRECT TIME STUDY

Somjintana Kanangkaew — 2025-09-30

Effective time management is crucial for the success of construction projects. Therefore, the study of standard time for brick wall installation is essential for construction planning and control. This research presents a study of the standard time for brick wall installation using the direct time study method. The study was conducted at a government hospital bathroom renovation and extension project in Chiang Mai Province. This research aimed to determine the standard time for half- red brick walling installation using the direct time study method and identify the various sub-activities involved. The results showed that brick wall installation can be divided into 19 sub-activities, with an average standard time of 750.20 minutes or 12.50 hours with 25 square meters. The three sub-activities with the most extended standard times were final inspection and cleaning 106.50 minutes, finishing the top row of bricks 82.60 minutes, and laying the top row 71.30 minutes, respectively. In addition, the standard time obtained from this study can be applied to brick wall installation planning, cost estimation, productivity assessment, and work process improvement.

DEVELOPING A SOFT SKILLS ENHANCEMENT MODEL FOR THIRD-PARTY INSPECTION ENGINEERS IN THAILAND

Wasawat Kitsiriteeraphak — 2025-09-30

This research aims to develop a competency enhancement model for essential soft skills required by third-party inspection engineers in Thailand. The study was conducted through a comprehensive process that included literature review, in-depth interviews, focus group discussions, questionnaire surveys, and factor analysis. The findings revealed four main components of soft skills: presentation skills, lifelong learning, complex problem-solving, and personality traits. The knowledge obtained was applied to the development of a soft skill enhancement model comprising four essential steps: (1) initial skill assessment to tailor development plans according to participant needs, (2) active learning-based training, (3) learning outcome evaluation through pre- and post-assessment, with performance categorized into three levels—basic, applied, and expert competencies, and (4) long-term follow-up using a portfolio system and periodic reassessment, with curriculum reviews and improvements scheduled at least every five years. Evaluation by experts and stakeholders from government, private sectors, and professional associations rated the curriculum as highly appropriate. The presentation skill received the highest average score (4.88), with recommendations to update the content, incorporate additional case studies, and enhance personality development on an individual basis. It can effectively support practical skill development through hands-on learning, alongside ongoing review of relevant soft skills to align with evolving work contexts. This research, therefore, proposes a systematic, practice-linked curriculum development approach that can be adapted to other professional fields, promoting efficient and sustainable competency enhancement for practitioners.

A STUDY ON QUALITY ISSUES AND SOLUTIONS IN ROAD CONSTRUCTION: A CASE STUDY OF ARMED FORCES DEVELOPMENT COMMAND, ROYAL THAI ARMED FORCES HEADQUARTERS

Arnon Nangsoongnern — 2025-09-30

This research aims to investigate the quality issues and solutions in road construction projects of the Armed Forces Development Command, Royal Thai Armed Forces Headquarters. The study also assesses and prioritizes the problems and their causes. The researcher employed the Delphi technique to develop a questionnaire. The research was divided into three phases. Phase 1 involved studying and gathering the causes of problems and potential solutions through interviews with 12 experts. The information collected was then categorized into various topics. Phase 2 focused on creating a questionnaire for experts to evaluate their level of agreement with the causes of the problems and proposed solutions. The results were used to create a questionnaire in Phase 3, which was distributed to 146 stakeholders involved in the road construction projects to assess their level of agreement with the problems, causes, and solutions. The research findings revealed that the stakeholders identified the following issues as the most important: personnel issues (M = 3.85 out of 5.00) with the primary cause being the shortage of skilled and specialized personnel, machinery issues (M = 3.83 out of 5.00) with the primary cause being outdated machinery, construction process issues (M = 3.78 out of 5.00) primarily caused by the inspection and quality control processes in construction, material issues (M = 3.77 out of 5.00) with the primary cause being the quality and source of materials, and environmental issues (M = 3.75 out of 5.00) primarily caused by the impact of climate and natural conditions. The research findings provide clear causes and solutions which can be applied by stakeholders and interested parties to manage and administer road construction projects and other related projects in the future.

A COMPARATIVE STUDY OF CEILING HEAT GAIN OF VENTILATED-DOUBLE CEILING AND INSULATED-CEILING

Ong-ard Udomsiri — 2025-09-30

This paper proposes a comparative investigation of ceiling heat gain reduction of ventilated-double ceiling and insulted-ceiling. The roof of test houses is shed roof with 25°. The attic and room volumetrics are 0.3 m³ and 1.2 m³, respectively. The total thermal resistance of the test house with insulated-ceiling and the test house with ventilated-double ceiling is equally valued to determine the thermal resistance due to ventilation through the double ceiling. Experimental results showed that the room temperature of the test house with ventilated-double ceiling is lower than the house with insulated-ceiling by maximum 1.5°C. The thermal image shown that the bottom surface (room side) of ceiling temperature of ventilated-double ceiling is lower than the house with insulated-ceiling by about 1.2°C. Finally, the functions of ventilated-double ceiling are to decrease the ceiling heat gain, to induce the ventilation rate, which provides the indoor thermal comfort.

DEMAND FORECASTING AND MODERN INVENTORY MANAGEMENT: A CASE STUDY ON AUTOMOTIVE PARTS

Wirunpuch Prommachan — 2025-09-30

This research aims to enhance the efficiency of inventory management for a children's car seat parts manufacturing company. The study utilized historical stock and sales data to forecast demand, comparing the effectiveness of the Moving Average method over 4-month and 6-month periods. A comparative analysis revealed that the 6-month Moving Average method yielded the most optimal results for procurement planning. Subsequently, ABC Analysis was applied to systematically categorize all spare parts and components based on their consumption value and usage volume. The analysis segmented the inventory into three primary groups: Group A, comprising 3 items (codes N005, N001, N009), which accounted for 39.96% of the usage volume and a high inventory value of 73.11%; Group B, with 2 items (codes N007, N0012), representing 36.53% of the usage volume and 13.68% of the inventory value; and Group C, consisting of 9 items (codes N0011, N0014, N002, N0013, N003, N006, N004, N0010, N008), which accounted for 23.52% of the usage volume and 13.21% of the inventory value. The findings of this study underscore that the combined application of these two techniques can significantly improve the company's inventory management by facilitating a strategic focus on high-value items, thereby reducing unnecessary costs and enhancing overall operational agility.

ENHANCING MAIZE LEAF DISEASE CLASSIFICATION PERFORMANCE USING IMAGE PROCESSING TECHNIQUES

keerachart suksut — 2025-09-30

The outbreak of maize (corn) diseases poses a major challenge, significantly reducing yield and affecting market prices. Timely and accurate diagnosis is essential for effective management, including prevention and treatment. However, self-diagnosis is often unreliable due to fatigue and symptom similarity. Artificial Intelligence (AI) offers a promising solution to reduce farmer burden and improve accuracy. Nevertheless, traditional algorithms may struggle with effective classification. This research proposes an enhanced maize disease classification approach using leaf images, employing HSV color space processing (to better distinguish disease-related color shades) and Data Augmentation (to increase data diversity and balance) prior to Deep Learning model training. Experimental results demonstrate an improved average classification accuracy of 93.17%, compared to 91.69% with conventional methods.